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Sample records for enzyme inhibitory properties

  1. Physicochemical, functional and angiotensin converting enzyme inhibitory properties of amaranth (Amaranthus hypochondriacus) 7S globulin.

    Science.gov (United States)

    Quiroga, Alejandra V; Aphalo, Paula; Ventureira, Jorge L; Martínez, E Nora; Añón, María C

    2012-01-30

    Amaranth 7S globulin is a minor globulin component and its impact on the properties of an amaranth protein ingredient depends on its proportion in the variety of amaranth being considered. Some physicochemical, functional and angiotesin I-converting enzyme (ACE) inhibitory properties of amaranth vicilin were studied in this work and compared with the 11S globulin. Fluorescence spectroscopy results indicated that 7S globulin tryptophans were more exposed to the solvent and, by calorimetry, the 7S globulin denaturation temperature (T(d) ) was found lower than the 11S globulin T(d) , suggesting a more flexible structure. The 7S globulin surface hydrophobicity was higher than that of the 11S globulin, which is in agreement with the better emulsifying properties of the 7S globulin. The solubility in neutral buffer of the 7S globulin (851 ± 25 g kg(-1) ) was also higher than that of the 11S globulin (195 ± 6 g kg(-1) ). Bioinformatic analyses showed the presence of ACE inhibitory peptides encrypted in 7S tryptic sequences and peptides released after in vitro gastrointestinal digestion showed a high ACE-inhibitory capacity (IC(50) = 0.17 g L(-1) ), similar to that of 11S globulin peptides. Compared with the 11S globulin, the 7S globulin presents similar ACE inhibitory activity and some functional advantages, better solubility and emulsifying activity, which suits some food requirements. The functional behavior has been related with the structural properties. Copyright © 2011 Society of Chemical Industry.

  2. Drying Methods Alter Angiotensin-I Converting Enzyme Inhibitory Activity, Antioxidant Properties, and Phenolic Constituents of African Mistletoe (Loranthus bengwensis L) Leaves.

    Science.gov (United States)

    Oboh, Ganiyu; Omojokun, Olasunkanmi Seun; Ademiluyi, Adedayo Oluwaseun

    2016-10-01

    This study investigated the most appropriate drying method (sun drying, oven drying, or air drying) for mistletoe leaves obtained from almond tree. The phenolic constituents were characterized using high-performance liquid chromatography-diode array detector, while the inhibitory effect of the aqueous extracts of the leaves on angiotensin-I converting enzyme (ACE) was determined in vitro as also the antioxidant properties. Oven-dried extract (kidney [276.09 μg/mL] and lungs [303.41 μg/mL]) had the highest inhibitory effect on ACE, while air-dried mistletoe extract (kidney [304.47 μg/mL] and lungs [438.72 μg/mL]) had the least. Furthermore, the extracts dose-dependently inhibited Fe(2+) and sodium nitroprusside-induced lipid peroxidation in rat's heart and kidney. Also, all extracts exhibited antioxidative properties as typified by their radical scavenging and Fe-chelating ability. Findings from this study revealed that oven drying is the best of the 3 drying methods used for mistletoe obtained from almond host tree, thus confirming that diversity in drying methods leads to variation in phenolic constituents and biological activity of plants. © The Author(s) 2015.

  3. Health attributes of ethnic vegetables consumed in the Eastern Anatolia region of Turkey: Antioxidant and enzyme-inhibitory properties

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    Abdullah Dalar

    2016-06-01

    Conclusions: Among the investigated ethnic vegetables, P. lanceolata and C. intybus represent a valuable source of antioxidant phytochemicals of phenolic nature that modulated in vitro the activities of digestive enzymes. These ethnic food sources diversify diet and enhance health attributes of foods.

  4. Inhibitory properties of 1,4-dideoxy-1,4-imino-d-arabinitol (DAB) derivatives acting on glycogen metabolising enzymes.

    Science.gov (United States)

    Díaz-Lobo, Mireia; Concia, Alda Lisa; Gómez, Livia; Clapés, Pere; Fita, Ignacio; Guinovart, Joan J; Ferrer, Joan C

    2016-09-26

    Glycogen synthase (GS) and glycogen phosphorylase (GP) are the key enzymes that control, respectively, the synthesis and degradation of glycogen, a multi-branched glucose polymer that serves as a form of energy storage in bacteria, fungi and animals. An abnormal glycogen metabolism is associated with several human diseases. Thus, GS and GP constitute adequate pharmacological targets to modulate cellular glycogen levels by means of their selective inhibition. The compound 1,4-dideoxy-1,4-imino-d-arabinitol (DAB) is a known potent inhibitor of GP. We studied the inhibitory effect of DAB, its enantiomer LAB, and 29 DAB derivatives on the activity of rat muscle glycogen phosphorylase (RMGP) and E. coli glycogen synthase (EcGS). The isoform 4 of sucrose synthase (SuSy4) from Solanum tuberosum L. was also included in the study for comparative purposes. Although these three enzymes possess highly conserved catalytic site architectures, the DAB derivatives analysed showed extremely diverse inhibitory potential. Subtle changes in the positions of crucial residues in their active sites are sufficient to discriminate among the structural differences of the tested inhibitors. For the two Leloir-type enzymes, EcGS and SuSy4, which use sugar nucleotides as donors, the inhibitory potency of the compounds analysed was synergistically enhanced by more than three orders of magnitude in the presence of ADP and UDP, respectively. Our results are consistent with a model in which these compounds bind to the subsite in the active centre of the enzymes that is normally occupied by the glucosyl residue which is transferred between donor and acceptor substrates. The ability to selectively inhibit the catalytic activity of the key enzymes of the glycogen metabolism may represent a new approach for the treatment of disorders of the glycogen metabolism.

  5. Antibacterial and glucosyltransferase enzyme inhibitory activity of helmyntostachyszelanica

    Science.gov (United States)

    Kuspradini, H.; Putri, AS; Mitsunaga, T.

    2018-04-01

    Helminthostachyszeylanica is a terrestrial, herbaceous, fern-like plant of southeastern Asia and Australia, commonly known as tunjuk-langit. This kind of plant have a medicinal properties such as treatment of malaria, dysentery and can be eaten with betel in the treatment of whooping cough. To evaluate the scientific basis for the use of the plant, the antimicrobial activities of extracts of the stem and leaves were evaluated. The bacteria used in this study is Streptococcus sobrinus, a species of gram-positive, that may be associated with human dental caries. The dried powdered plant parts were extracted using methanol and 50% aqueous extract and screened for their antibacterial effects of Streptococcus sobrinus using the 96 well-plate microdilution broth method. The inhibitory activities of its related enzyme were also determined. The plant extracts showed variable antibacterial and Glucosyltransferase enzyme inhibitory activity while some extracts could not cause any inhibition. It was shown that 50% ethanolics of Helminthostachyzeylanica stem have a potency as anti dental caries agents.

  6. Correlation between enzymes inhibitory effects and antioxidant ...

    African Journals Online (AJOL)

    ... and phytochemical content of fractions was investigated. The n-butanol fraction showed significant α-glucosidase and α-amylase inhibitory effects (IC50 values 15.1 and 39.42 μg/ml, respectively) along with the remarkable antioxidant activity when compared to the other fractions. High performance liquid chromatography ...

  7. Antioxidant and inhibitory properties of Clerodendrum volubile leaf extracts on key enzymes relevant to non-insulin dependent diabetes mellitus and hypertension

    Directory of Open Access Journals (Sweden)

    Stephen A. Adefegha

    2016-07-01

    Conclusion: The inhibitory properties of phenolic rich extracts on α-amylase, α-glucosidase, ACE, and Fe2+- and sodium nitroprusside-induced lipid peroxidation in the pancreas could be attributed to the antioxidant properties of the extracts and their phenolic composition. The stronger action of the bound phenolic extract on α-glucosidase may provide the possible bioactivity at the brush border end of the intestinal wall. This study may thus suggest that leaves represent a functional food and nutraceutical in the management of non-insulin dependent diabetes mellitus and hypertension.

  8. Enzyme inhibitory activity of selected Philippine plants

    International Nuclear Information System (INIS)

    Sasotona, Joseph S.; Hernandez, Christine C.

    2015-01-01

    In the Philippines, the number one cause of death are cardiovascular diseases. Diseases linked with inflammation are proliferating. This research aims to identify plant extracts that have potential activity of cholesterol-lowering, anti-hypertension, anti-gout, anti-inflammatory and fat blocker agents. Although there are commercially available drugs to treat the aforementioned illnesses, these medicine have adverse side-effects, aside from the fact that they are expensive. The results of this study will serve as added knowledge to contribute to the development of cheaper, more readily available, and effective alternative medicine. 100 plant extracts from different areas in the Philippines have been tested for potential inhibitory activity against Hydroxymethylglutaryl-coenzyme A (HMG-CoA), Lipoxygenase, and Xanthine Oxidase. The plant samples were labeled with codes and distributed to laboratories for blind testing. The effective concentration of the samples tested for Xanthine oxidase is 100 ppm. Samples number 9, 11, 14, 29, 43, 46, and 50 have shown significant inhibitory activity at 78.7%, 78.4%, 70%, 89.2%, 79%, 67.4%, and 67.5% respectively. Samples tested for Lipoxygenase inhibition were set at 33ppm. Samples number 2, 37, 901, 1202, and 1204 have shown significant inhibitory activity at 66, 84.9%, 88.55%, 93.3%, and 84.7% respectively. For HMG-CoA inhibition, the effective concentration of the samples used was 100 ppm. Samples number 1 and 10 showed significant inhibitory activity at 90.1% and 81.8% respectively. (author)

  9. Angiotensin I-Converting Enzyme (ACE Inhibitory Activity and ACE Inhibitory Peptides of Salmon (Salmo salar Protein Hydrolysates Obtained by Human and Porcine Gastrointestinal Enzymes

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    Małgorzata Darewicz

    2014-08-01

    Full Text Available The objectives of the present study were two-fold: first, to detect whether salmon protein fractions possess angiotensin I-converting enzyme (ACE inhibitory properties and whether salmon proteins can release ACE inhibitory peptides during a sequential in vitro hydrolysis (with commercial porcine enzymes and ex vivo digestion (with human gastrointestinal enzymes. Secondly, to evaluate the ACE inhibitory activity of generated hydrolysates. A two-step ex vivo and in vitro model digestion was performed to simulate the human digestion process. Salmon proteins were degraded more efficiently by porcine enzymes than by human gastrointestinal juices and sarcoplasmic proteins were digested/hydrolyzed more easily than myofibrillar proteins. The ex vivo digested myofibrillar and sarcoplasmic duodenal samples showed IC50 values (concentration required to decrease the ACE activity by 50% of 1.06 and 2.16 mg/mL, respectively. The in vitro hydrolyzed myofibrillar and sarcoplasmic samples showed IC50 values of 0.91 and 1.04 mg/mL, respectively. Based on the results of in silico studies, it was possible to identify 9 peptides of the ex vivo hydrolysates and 7 peptides of the in vitro hydrolysates of salmon proteins of 11 selected peptides. In both types of salmon hydrolysates, ACE-inhibitory peptides IW, IY, TVY and VW were identified. In the in vitro salmon protein hydrolysates an ACE-inhibitory peptides VPW and VY were also detected, while ACE-inhibitory peptides ALPHA, IVY and IWHHT were identified in the hydrolysates generated with ex vivo digestion. In our studies, we documented ACE inhibitory in vitro effects of salmon protein hydrolysates obtained by human and as well as porcine gastrointestinal enzymes.

  10. Improvement in antioxidant activity, angiotensin-converting enzyme inhibitory activity and in vitro cellular properties of fermented pepino milk by Lactobacillus strains containing the glutamate decarboxylase gene.

    Science.gov (United States)

    Chiu, Tsai-Hsin; Tsai, Shwu-Jene; Wu, Tsung-Yen; Fu, Szu-Chieh; Hwang, Yi-Ting

    2013-03-15

    The purpose of this study was to evaluate the functional potential of fermented pepino extract (PE) milk by Lactobacillus strains containing the glutamate decarboxylase (GAD) gene. Three Lactobacillus strains were selected, including L. brevis BCRC 12310, L. casei BCRC 14082 and L. salivarius subsp. salivarius BCRC 14759. The contents of free amino acids, total phenolics content, total carotenoids and the associated functional and antioxidant abilities were analyzed, including angiotensin-converting enzyme (ACE) inhibition activity, 1,1-diphenyl-2-picylhydrazyl (DPPH) radical-scavenging ability and oxygen radical absorbance capacity (ORAC). Cell proliferation of fermented PE milk was also evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Compared to the unfermented PE, fermented PE milk from Lactobacillus strains with the GAD gene showed higher levels of total phenolics, γ-aminobutyric acid, ACE inhibitory activity, DPPH, and ORAC. The viability of human promyelocytic leukemia cells (HL-60) determined by the MTT method decreased significantly when the cells were incubated with the PE and the fermented PE milk extracts. The consumption of fermented PE milk from Lactobacillus strains with the GAD gene is expected to benefit health. Further application as a health food is worthy of investigation. © 2012 Society of Chemical Industry. © 2012 Society of Chemical Industry.

  11. Effect of partially purified angiotensin converting enzyme inhibitory ...

    African Journals Online (AJOL)

    This study evaluated the effect of partially-purified angiotensin converting enzyme (ACE) inhibitory proteins obtained from the leaves of Moringa oleifera on blood glucose, serum ACE activity and lipid profile of alloxaninduced diabetic rats. Twenty-five apparently healthy male albino rats were divided into five groups of five ...

  12. Angiotensin I-Converting Enzyme (ACE Inhibitory Activity, Antioxidant Properties, Phenolic Content and Amino Acid Profiles of Fucus spiralis L. Protein Hydrolysate Fractions

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    Lisete Paiva

    2017-10-01

    Full Text Available Food protein-derived hydrolysates with multi-bioactivities such as antihypertensive and antioxidant properties have recently received special attention since both activities can play significant roles in preventing cardiovascular diseases. This study reports, for the first time, the angiotensin I-converting enzyme (ACE-inhibition and antioxidant properties of ultrafiltrate fractions (UF with different molecular weight ranges (<1, 1–3 and ≥3 kDa obtained from Fucus spiralis protein hydrolysate (FSPH digested with cellulase–bromelain. The amino acids profile, recovery yield, protein, peptide and total phenolic contents of these FSPH-UF, and the in vitro digestibility of F. spiralis crude protein were also investigated. FSPH-UF ≥3 kDa presented remarkably higher ACE-inhibition, yield, peptide and polyphenolic (phlorotannins contents. Antioxidant analysis showed that FSPH-UF <1 kDa and ≥3 kDa exhibited significantly higher scavenging of 2,2-diphenyl-1-picrylhydrazyl radical and ferrous ion-chelating (FIC activity. FSPH-UF ≥3 kDa had also notably higher ferric reducing antioxidant power (FRAP. Strong correlations were observed between ACE-inhibition and antioxidant activities (FIC and FRAP. The results suggest that ACE-inhibition and antioxidant properties of FSPH-UF may be due to the bioactive peptides and polyphenols released during the enzymatic hydrolysis. In conclusion, this study shows the potential use of defined size FSPH-UF for the prevention/treatment of hypertension and/or oxidative stress-related diseases.

  13. Selected Enzyme Inhibitory Effects of Euphorbia characias Extracts

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    Antonella Fais

    2018-01-01

    Full Text Available Extracts of aerial part of Euphorbia characias were examined to check potential inhibitors for three selected enzymes involved in several metabolic disorders. Water and ethanol extracts from leaves and flowers showed in vitro inhibitory activity toward α-amylase, α-glucosidase, and xanthine oxidase. IC50 values were calculated for all the extracts and the ethanolic extracts were found to exert the best effect. In particular, for the α-glucosidase activity, the extracts resulted to be 100-fold more active than the standard inhibitor. The inhibition mode was investigated by Lineweaver-Burk plot analysis. E. characias extracts display different inhibition behaviors toward the three enzymes acting as uncompetitive, noncompetitive, and mixed-type inhibitors. Moreover, ethanolic extracts of E. characias showed no cytotoxic activity and exhibited antioxidant capacity in a cellular model. The LC-DAD metabolic profile was also performed and it showed that leaves and flowers extracts contain high levels of quercetin derivatives. The results suggest that E. characias could be a promising source of natural inhibitors of the enzymes involved in carbohydrate uptake disorders and oxidative stress.

  14. Chemical Composition and Enzymes Inhibitory, Brine Shrimp Larvae Toxicity, Antimicrobial and Antioxidant Activities of Caloplaca biatorina

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    Tahereh Valadbeigi

    2016-10-01

    Full Text Available Background This study evaluated the brine shrimp larvae toxicity and enzymes inhibitory especially anti-diabetic potential of Caloplaca biatorina via in vitro inhibition of α-amylase and α-glucosidase using the methanol extracts. Also aldehyde oxidase and xanthine oxidase enzymes inhibitory, cytotoxicity, and antioxidant activities of the species were determined. Methods In this experimental study, different concentrations of the extracts (0.2, 5.0, 1 and 1.5 mg/mL were incubated with enzyme substrate solution and the percentage of enzyme inhibitory activity and IC50 was calculated. Folin- Ciocalteu reagent and aluminium chloride colorimetric methods were used to estimate total phenolic and flavonoid content of extracts. The toxicity of the extract was assessed using the brine shrimp lethality bioassay. The minimal inhibitory concentration (MIC and minimum bactericidal concentration (MBC were determined. High-performance liquid chromatography and Thin-layer chromatography analysis were evaluated. The data were analyzed by SPSS V.21 software. Results Parietin, Emodin, 1,8-Dihydroxy-3-(hydroxymethyl-6- methoxy-9.10-anthracenedione and Rhein were identified. The extract showed strong α-glucosidase, aldehyde oxidase and xanthine oxidase inhibitory activities with IC50 value of 17.12, 40.09 and 11.02 µg/mL respectively. Also methanol extract displayed the strongest DPPH radical scavenging and brine shrimp toxicity (IC50 = 91.11 properties. Conclusions The result obtained suggests that the C. biatorina extract can be classified as non-toxic. Also, it revealed the antioxidant and antidiabetic potential of the lichen.

  15. Acetyl-cholinesterase Enzyme Inhibitory Effect of Calophyllum species

    African Journals Online (AJOL)

    Purpose: To search for new acetylcholinesterase enzyme inhibitors from Calopyllum species. Methods: Six stem bark extracts of Calophyllum inophyllum, C. soulattri, C. teysmannii, C. lowii, C. benjaminum and C. javanicum were subjected to anti-cholinesterase analysis against acetylcholinesterase (AChE) enzyme using ...

  16. Antioxidant and Angiotensin-Converting Enzyme Inhibitory Activity of Eucalyptus camaldulensis and Litsea glaucescens Infusions Fermented with Kombucha Consortium

    OpenAIRE

    Gamboa-Gómez, Claudia I.; González-Laredo, Rubén F.; Gallegos-Infante, José Alberto; Pérez, MŞ del Mar Larrosa; Moreno-Jiménez, Martha R.; Flores-Rueda, Ana G.; Rocha-Guzmán, Nuria E.

    2016-01-01

    Physicochemical properties, consumer acceptance, antioxidant and angiotensin-converting enzyme (ACE) inhibitory activities of infusions and fermented beverages of Eucalyptus camaldulensis and Litsea glaucescens were compared. Among physicochemical parameters, only the pH of fermented beverages decreased compared with the unfermented infusions. No relevant changes were reported in consumer preference between infusions and fermented beverages. Phenolic profi le measured by UPLC MS/MS analysis d...

  17. Acetyl-cholinesterase Enzyme Inhibitory Effect of Calophyllum species

    African Journals Online (AJOL)

    1Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, ... Purpose: To search for new acetylcholinesterase enzyme inhibitors from ... Index Medicus, JournalSeek, Journal Citation Reports/Science Edition, .... The data are expressed as mean ± standard .... The authors acknowledge financial support from.

  18. Purification of Angiotensin Converting Enzyme Inhibitory Peptide Derived From Kacang Goat Meat Protein Hydrolysate

    OpenAIRE

    Jamhari, J; Yusiati, L.M; Suryanto, E; Cahyanto, M.N; Erwanto, Y; Muguruma, M

    2013-01-01

    The objective of this study was to identify the Angiotensin Converting Enzyme (ACE) inhibitorypeptide derived from Kacang goat meat protein hydrolysate. Kacang goat meat loin section washydrolyzed with pepsin, trypsin and chymotrypsin. Protein hydrolysate of Kacang goat meat was thentested the protein concentration and ACE inhibitory activity. ACE inhibitory peptide of the proteinhydrolysate was purified through several steps of purification by column SEP-PAK Plus C18 Cartridgeand RP-HPLC usi...

  19. Enzyme Inhibitory and Molecular Docking Studies on Some Organic Molecules of Natural Occurrence

    International Nuclear Information System (INIS)

    Abbasi, M. A.; Hussain, G.; Rehman, A. U.; Shahwar, D.; Mohyuddin, A.; Ashraf, M.; Rahman, J.; Lodhi, M. A.; Khan, F. A.

    2016-01-01

    In the present study, in vitro enzyme inhibitory studies on cinchonidine (1), cinchonine (2), quinine (3), noscapine (narcotine, 4) and santonine (5) were carried out. The various enzymes included in the study were lipoxygenase, xanthine oxidase, acetyl cholinesterase, butyryl cholinesterase and protease. The results revealed that 2, 3, and 4 were moderate active against lipoxygenase and xanthine oxidase enzymes. The molecule 3 possessed weak activity against butyryl cholinesterase enzyme while remaining molecules were inactive against this enzyme. However, all these compounds were inactive against acetyl cholinestrase and protease enzymes. The synthesized compounds were computationally docked into the active site of lipoxygenase enzyme. The compounds 3 and 4 showed decent interactions, hence strengthening the observed results. (author)

  20. High similarity of phylogenetic profiles of rate-limiting enzymes with inhibitory relation in Human, Mouse, Rat, budding Yeast and E. coli.

    Science.gov (United States)

    Zhao, Min; Qu, Hong

    2011-11-30

    The phylogenetic profile is widely used to characterize functional linkage and conservation between proteins without amino acid sequence similarity. To survey the conservative regulatory properties of rate-limiting enzymes (RLEs) in metabolic inhibitory network across different species, we define the enzyme inhibiting pair as: where the first enzyme in a pair is the inhibitor provider and the second is the target of the inhibitor. Phylogenetic profiles of enzymes in the inhibiting pairs are further generated to measure the functional linkage of these enzymes during evolutionary history. We find that the RLEs generate, on average, over half of all in vivo inhibitors in each surveyed model organism. And these inhibitors inhibit on average over 85% targets in metabolic inhibitory network and cover the majority of targets of cross-pathway inhibiting relations. Furthermore, we demonstrate that the phylogenetic profiles of the enzymes in inhibiting pairs in which at least one enzyme is rate-limiting often show higher similarities than those in common inhibiting enzyme pairs. In addition, RLEs, compared to common metabolic enzymes, often tend to produce ADP instead of AMP in conservative inhibitory networks. Combined with the conservative roles of RLEs in their efficiency in sensing metabolic signals and transmitting regulatory signals to the rest of the metabolic system, the RLEs may be important molecules in balancing energy homeostasis via maintaining the ratio of ATP to ADP in living cells. Furthermore, our results indicate that similarities of phylogenetic profiles of enzymes in the inhibiting enzyme pairs are not only correlated with enzyme topological importance, but also related with roles of the enzymes in metabolic inhibitory network.

  1. Inhibitory Competition between Shape Properties in Figure-Ground Perception

    Science.gov (United States)

    Peterson, Mary A.; Skow, Emily

    2008-01-01

    Theories of figure-ground perception entail inhibitory competition between either low-level units (edge or feature units) or high-level shape properties. Extant computational models instantiate the 1st type of theory. The authors investigated a prediction of the 2nd type of theory: that shape properties suggested on the ground side of an edge are…

  2. Enzyme inhibitory and radical scavenging effects of some antidiabetic plants of Turkey

    Science.gov (United States)

    Orhan, Nilüfer; Hoçbaç, Sanem; Orhan, Didem Deliorman; Asian, Mustafa; Ergun, Fatma

    2014-01-01

    Objective(s): Ethnopharmacological field surveys demonstrated that many plants, such as Gentiana olivieri, Helichrysum graveolens, Helichrysum plicatum ssp. plicatum, Juniperus oxycedrus ssp. oxycedrus, Juniperus communis var. saxatilis, Viscum album (ssp. album, ssp. austriacum), are used as traditional medicine for diabetes in different regions of Anatolia. The present study was designed to evaluate the in vitro antidiabetic effects of some selected plants, tested in animal models recently. Materials and Methods: α-glucosidase and α-amylase enzyme inhibitory effects of the plant extracts were investigated and Acarbose was used as a reference drug. Additionally, radical scavenging capacities were determined using 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) ABTS radical cation scavenging assay and total phenolic content of the extracts were evaluated using Folin Ciocalteu method. Results: H. graveolens ethanol extract exhibited the highest inhibitory activity (55.7 % ± 2.2) on α-amylase enzyme. Additionally, J. oxycedrus hydro-alcoholic leaf extract had potent α-amylase inhibitory effect, while the hydro-alcoholic extract of J. communis fruit showed the highest α-glucosidase inhibitory activity (IC50: 4.4 μg/ml). Conclusion: Results indicated that, antidiabetic effect of hydro-alcoholic extracts of H. graveolens capitulums, J. communis fruit and J. oxycedrus leaf might arise from inhibition of digestive enzymes. PMID:25140204

  3. Enzyme inhibitory and radical scavenging effects of some antidiabetic plants of Turkey

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    Nilüfer Orhan

    2014-06-01

    Full Text Available Objective(s:Ethnopharmacological field surveys demonstrated that many plants, such as Gentiana olivieri, Helichrysum graveolens, Helichrysum plicatum ssp. plicatum, Juniperus oxycedrus ssp. oxycedrus, Juniperus  communis var. saxatilis, Viscum album (ssp. album, ssp. austriacum, are used as traditional medicine for diabetes in different regions of Anatolia. The present study was designed to evaluate the in vitro antidiabetic effects of some selected plants, tested in animal models recently. Materials and Methods: α-glucosidase and α-amylase enzyme inhibitory effects of the plant extracts were investigated and Acarbose was used as a reference drug. Additionally, radical scavenging capacities were determined using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid ABTS radical cation scavenging assay and total phenolic content of the extracts were evaluated using Folin Ciocalteu method. Results: H. graveolens ethanol extract exhibited the highest inhibitory activity (55.7 % ± 2.2 on α-amylase enzyme. Additionally, J. oxycedrus hydro-alcoholic leaf extract had potent α-amylase inhibitory effect, while the hydro-alcoholic extract of J. communis fruit showed the highest α-glucosidase inhibitory activity (IC50: 4.4 μg/ml. Conclusion:Results indicated that, antidiabetic effect of hydro-alcoholic extracts of H. graveolens capitulums, J. communis fruit and J. oxycedrus leaf might arise from inhibition of digestive enzymes.

  4. Characterization of angiotensin-converting enzyme inhibitory activity of fermented milk produced by Lactobacillus helveticus.

    Science.gov (United States)

    Chen, Yongfu; Li, Changkun; Xue, Jiangang; Kwok, Lai-yu; Yang, Jie; Zhang, Heping; Menghe, Bilige

    2015-08-01

    Hypertension affects up to 30% of the adult population in most countries. It is a known risk factor for cardiovascular diseases, including coronary heart disease, peripheral artery disease, and stroke. Owing to the increased health awareness of consumers, the application of angiotensin-converting enzyme (ACE)-inhibitory peptides produced by Lactobacillushelveticus to prevent or control high blood pressure has drawn wide attention. A total of 59 L. helveticus strains were isolated from traditional fermented dairy products and the ACE-inhibitory activity of the fermented milks produced with the isolated microorganisms was assayed. The ACE-inhibitory activity of 38 L. helveticus strains was more than 50%, and 3 strains (IMAU80872, IMAU80852, and IMAU80851) expressing the highest ACE-inhibitory activity were selected for further studies. Particularly, the gastrointestinal protease tolerance and thermostability of the ACE-inhibitory activity in the fermented milks were assessed. Based on these 2 criteria, IMAU80872 was found to be superior over the other 2 strains. Furthermore, IMAU80872 exhibited a high in vitro ACE-inhibitory activity at the following fermentation conditions: fermentation temperature at 40°C, inoculation concentration of 1×10(6) cfu/mL, and fermentation for 18h. Finally, by using ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry analysis, we observed changes of the metabolome along the milk fermentation process of IMAU80872. Furthermore, 6 peptides were identified, which might have ACE-inhibitory activity. In conclusion, we identified a novel ACE-inhibitory L. helveticus strain suitable for the production of fermented milk or other functional dairy products. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  5. Production, optimisation and characterisation of angiotensin converting enzyme inhibitory peptides from sea cucumber (Stichopus japonicus) gonad.

    Science.gov (United States)

    Zhong, Chan; Sun, Le-Chang; Yan, Long-Jie; Lin, Yi-Chen; Liu, Guang-Ming; Cao, Min-Jie

    2018-01-24

    In this study, production of bioactive peptides with angiotensin converting enzyme (ACE) inhibitory activity from sea cucumber (Stichopus japonicus) gonad using commercial protamex was optimised by response surface methodology (RSM). As a result, the optimal condition to achieve the highest ACE inhibitory activity in sea cucumber gonad hydrolysate (SCGH) was hydrolysis for 1.95 h and E/S of 0.75%. For further characterisation, three individual peptides (EIYR, LF and NAPHMR) were purified and identified. The peptide NAPHMR showed the highest ACE inhibitory activity with IC 50 of 260.22 ± 3.71 μM. NAPHMR was stable against simulated gastrointestinal digestion and revealed no significant cytotoxicity toward Caco-2 cells. Molecular docking study suggested that Arg, His and Asn residues in NAPHMR interact with the S2 pocket or Zn 2+ binding motifs of ACE via hydrogen or π-bonds, potentially contributing to ACE inhibitory effect. Sea cucumber gonad is thus a potential resource to produce ACE inhibitory peptides for preparation of functional foods.

  6. Effect of Jatropha curcas Peptide Fractions on the Angiotensin I-Converting Enzyme Inhibitory Activity

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    Maira R. Segura-Campos

    2013-01-01

    Full Text Available Hypertension is one of the most common worldwide diseases in humans. Angiotensin I-converting enzyme (ACE plays an important role in regulating blood pressure and hypertension. An evaluation was done on the effect of Alcalase hydrolysis of defatted Jatropha curcas kernel meal on ACE inhibitory activity in the resulting hydrolysate and its purified fractions. Alcalase exhibited broad specificity and produced a protein hydrolysate with a 21.35% degree of hydrolysis and 34.87% ACE inhibition. Ultrafiltration of the hydrolysate produced peptide fractions with increased biological activity (24.46–61.41%. Hydrophobic residues contributed substantially to the peptides’ inhibitory potency. The 5–10 and <1 kDa fractions were selected for further fractionation by gel filtration chromatography. ACE inhibitory activity (% ranged from 22.66 to 45.96% with the 5–10 kDa ultrafiltered fraction and from 36.91 to 55.83% with the <1 kDa ultrafiltered fraction. The highest ACE inhibitory activity was observed in F2 ( μg/mL from the 5–10 kDa fraction and F1 ( μg/mL from the <1 kDa fraction. ACE inhibitory fractions from Jatropha kernel have potential applications in alternative hypertension therapies, adding a new application for the Jatropha plant protein fraction and improving the financial viability and sustainability of a Jatropha-based biodiesel industry.

  7. A virtual screening method for inhibitory peptides of Angiotensin I-converting enzyme.

    Science.gov (United States)

    Wu, Hongxi; Liu, Yalan; Guo, Mingrong; Xie, Jingli; Jiang, XiaMin

    2014-09-01

    Natural small peptides from foods have been proven to be efficient inhibitors of Angiotensin I-converting enzyme (ACE) for the regulation of blood pressure. The traditional ACE inhibitory peptides screening method is both time consuming and money costing, to the contrary, virtual screening method by computation can break these limitations. We establish a virtual screening method to obtain ACE inhibitory peptides with the help of Libdock module of Discovery Studio 3.5 software. A significant relationship between Libdock score and experimental IC(50) was found, Libdock score = 10.063 log(1/IC(50)) + 68.08 (R(2) = 0.62). The credibility of the relationship was confirmed by testing the coincidence of the estimated log(1/IC(50)) and measured log(1/IC(50)) (IC(50) is 50% inhibitory concentration toward ACE, in μmol/L) of 5 synthetic ACE inhibitory peptides, which was virtual hydrolyzed and screened from a kind of seafood, Phascolosoma esculenta. Accordingly, Libdock method is a valid IC(50) estimation tool and virtual screening method for small ACE inhibitory peptides. © 2014 Institute of Food Technologists®

  8. Acetylcholinesterase Inhibitory and Antioxidant Properties of Euphorbiacharacias Latex

    Directory of Open Access Journals (Sweden)

    Francesca Pintus

    2013-03-01

    Full Text Available The aim of the present study was to evaluate the acetylcholinesterase inhibitory capacity and the antioxidant properties of extracts of Euphorbia characias latex, a Mediterranean shrub. We performed a new extraction method involving the use of the trichloroacetic acid. The extract showed high antioxidant activity, was rich in total polyphenolic and flavonoid content and exhibited substantial inhibition of acetylcholinesterase activity.

  9. distribution, abundance and properties of restriction enzymes

    African Journals Online (AJOL)

    DNA of granule-bound starch synthase (GBSS) I and II with a view to ... properties for manipulation of the genes for production of modified starch. .... procurement, storage and handling of the ..... been made on restriction enzymes of potato,.

  10. Effect of Jatropha curcas Peptide Fractions on the Angiotensin I-Converting Enzyme Inhibitory Activity

    Science.gov (United States)

    Segura-Campos, Maira R.; Peralta-González, Fanny; Castellanos-Ruelas, Arturo; Chel-Guerrero, Luis A.; Betancur-Ancona, David A.

    2013-01-01

    Hypertension is one of the most common worldwide diseases in humans. Angiotensin I-converting enzyme (ACE) plays an important role in regulating blood pressure and hypertension. An evaluation was done on the effect of Alcalase hydrolysis of defatted Jatropha curcas kernel meal on ACE inhibitory activity in the resulting hydrolysate and its purified fractions. Alcalase exhibited broad specificity and produced a protein hydrolysate with a 21.35% degree of hydrolysis and 34.87% ACE inhibition. Ultrafiltration of the hydrolysate produced peptide fractions with increased biological activity (24.46–61.41%). Hydrophobic residues contributed substantially to the peptides' inhibitory potency. The 5–10 and Jatropha kernel have potential applications in alternative hypertension therapies, adding a new application for the Jatropha plant protein fraction and improving the financial viability and sustainability of a Jatropha-based biodiesel industry. PMID:24224169

  11. Escherichia coli photoreactivating enzyme: purification and properties

    International Nuclear Information System (INIS)

    Snapka, R.M.; Sutherland, B.M.

    1980-01-01

    Researchers have purified large quantities of Escherichia coli photoreactivating enzyme to apparent homogeneity and have studied its physical and chemical properties. The enzyme has a molecular weight of 36,800 and a S/sub 20,w/ 0 of 3.72 S. Amino acid analysis revealed an apparent absence of tryptophan, a low content of aromatic residues, and the presence of no unusual amino acids. The N terminus is arginine. The purified enzyme contained up to 13% carbohydrate by weight. The carbohydrate was composed of mannose, galactose, glucose, and N-acetylglucosamine. The enzyme is also associated with RNA containing uracil, adenine, guanine, and cytosine with no unusual bases detected

  12. Polyphenols isolated from Acacia mearnsii bark with anti-inflammatory and carbolytic enzyme inhibitory activities

    Institute of Scientific and Technical Information of China (English)

    XIONG Jia; GRACE Mary H; ESPOSITO Debora; KOMARNYTSKY Slavko; WANG Fei; LILA Mary Ann

    2017-01-01

    The present study was designed to characterize the polyphenols isolated from Acacia mearnsii bark crude extract (B) and fractions (B1-B7) obtained by high-speed counter-current chromatography (HSCCC) and evaluate their anti-inflammatory and carbolytic enzymes (α-glucosidase and α-amylase) inhibitory activities.Fractions B4,B5,B6,B7 (total phenolics 850.3,983.0,843.9,and 572.5 mg·g-1,respectively;proanthocyanidins 75.7,90.5,95.0,and 44.8 mg·g-1,respectively) showed significant activities against reactive oxygen species (ROS),nitric oxide (NO) production,and expression of pro-inflammatory genes interleukin-lβ (IL-1β) and inducible nitric oxide synthase (iNOS) in a lipopolysaccharide (LPS)-stimulated mouse macrophage cell line RAW 264.7.All the extracts suppressed α-glucosidase and α-amylase activities,two primary enzymes responsible for carbohydrate digestion.A.mearnsii bark samples possessed significantly stronger inhibitory effects against α-glucosidase enzyme (IC50 of 0.4-1.4 tg·mL-1) than the pharmaceutical acarbose (IC50 141.8 μg·mL-1).B6 and B7 (IC5017.6 and 11.7 μg·mL-1,respectively) exhibited α-amylase inhibitory activity as efficacious as acarbose (IC50 15.4 μg·mL-1).Moreover,B extract,at 25 μg·mL-l,significantly decreased the non-mitochondrial oxidative burst that is often associated with inflammatory response in human monocytic macrophages.

  13. Antioxidant and enzyme inhibitory activities of Plebeian herba (Salvia plebeia R. Br.) under different cultivation conditions.

    Science.gov (United States)

    Chen, Lei; Kang, Young-Hwa

    2014-03-12

    An adaptation of cultural management to the specific cultural system, as well as crop demand, can further result in the improvement of the quality of horticultural products. Therefore, this study focused on the antioxidant and enzyme inhibitory activities of Plebeian herba (Salvia plebeia R. Br.) grown in hydroponics in comparison with those of the plant grown in soil. The antioxidant activities of Plebeian herba extract were measured as 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging abilities as well as the reducing power by decreasing nitric oxide (NO) and superoxide dismutase activity (SOD) in vitro. Interestingly, by comparison with hydroponics and traditional cultivation, Plebeian herba cultivated in nutrition-based soil improved inhibitory effect on free radicals of DPPH, ABTS, and NO and increased the contents of phenolics such as caffeic acid (1), luteolin-7-glucoside (2), homoplantaginin (3), hispidulin (4), and eupatorin. Free radical scavenging and SOD activity, as well as α-glucosidase inhibitory effect, were higher in Plebeian herba grown in nutrition-based soil than in plants grown in hydroponics and traditional condition.

  14. PURIFICATION OF ANGIOTENSIN CONVERTING ENZYME INHIBITORY PEPTIDE DERIVED FROM KACANG GOAT MEAT PROTEIN HYDROLYSATE

    Directory of Open Access Journals (Sweden)

    J. Jamhari

    2014-10-01

    Full Text Available The objective of this study was to identify the Angiotensin Converting Enzyme (ACE inhibitorypeptide derived from Kacang goat meat protein hydrolysate. Kacang goat meat loin section washydrolyzed with pepsin, trypsin and chymotrypsin. Protein hydrolysate of Kacang goat meat was thentested the protein concentration and ACE inhibitory activity. ACE inhibitory peptide of the proteinhydrolysate was purified through several steps of purification by column SEP-PAK Plus C18 Cartridgeand RP-HPLC using a Cosmosil column 5PE-SM, 4.6 x 250 mm. The sequence of amino acid of ACEinhibitory peptide was identified by amino acid sequencer. The results showed that amino acidssequence of ACE inhibitory peptide derived from protein hydrolysate of Kacang goat meat was leu-thrglu-ala-pro-leu-asn-pro-lys-ala-arg- asn-glu-lys. It had a molecular weight (MW of 1581 and occurredat the position of 20th to 33rd residues of b-actin of goat meat protein (Capra hircus. The ACE inhibitoryactivity (IC50 of the peptide was 190 mg/mL or 120 mM.

  15. Fungal growth inhibitory properties of new phytosphingolipid analogues.

    Science.gov (United States)

    Mormeneo, D; Manresa, A; Casas, J; Llebaria, A; Delgado, A

    2008-04-01

    To study the growth inhibitory properties of a series of phytosphingosine (PHS) and phytoceramide (PHC) analogues. A panel of two yeast (Candida albicans and Saccharomyces cerevisiae) and six moulds (Aspergillus repens, Aspergillus niger, Penicillium chrysogenum, Cladosporium cladosporioides, Arthroderma uncinatum and Penicillium funiculosum) has been used in this study. A series of new PHS and PHC analogues differing at the sphingoid backbone and the functional group at C1 position were synthesized. Among PHS analogues, 1-azido derivative 1c, bearing the natural D-ribo stereochemistry, showed a promising growth inhibitory profile. Among PHC analogues, compound 12, with a bulky N-pivaloyl group and a Z double bond at C3 position of the sphingoid chain, was the most active growth inhibitor. Minimal inhibitory concentration values were in the range of 23-48 micromol l(-1) for 1c and 44-87 micromol l(-1) for 12. Only scattered data on the antifungal activity of phytosphingolipids have been reported in the literature. This is the first time that a series of analogues of this kind are tested and compared to discern their structural requirements for antifungal activity.

  16. Bioaccessibility and inhibitory effects on digestive enzymes of carnosic acid in sage and rosemary.

    Science.gov (United States)

    Ercan, Pınar; El, Sedef Nehir

    2018-04-28

    In this study, the aim was to determine the bioaccessibilities of carnosic acid in sage and rosemary and in vitro inhibitory effects of these samples on lipid and starch digestive enzymes by evaluating the lipase, α-amylase and α-glucosidase enzyme inhibition activities. The content of carnosic acid in rosemary (18.72 ± 0.33 mg/g) was found to be higher than that content of that in sage (3.76 ± 0.13 mg/g) (p sage and rosemary, respectively. The tested sage and rosemary showed inhibitory activity against α-glucosidase (Concentration of inhibitor required to produce a 50% inhibition of the initial rate of reaction - IC 50 88.49 ± 2.35, 76.80 ± 1.68 μg/mL, respectively), α-amylase (IC 50 107.65 ± 12.64, 95.65 ± 2.73 μg/mL, respectively) and lipase (IC 50 6.20 ± 0.63, 4.31 ± 0.62 μg/mL, respectively). Furthermore, to the best of our knowledge, this is the first work that carnosic acid standard equivalent inhibition capacities (CAEIC 50 ) for these food samples were determined and these values were in agreement with the IC 50 values. These results show that sage and rosemary are potent inhibitors of lipase, α-amylase and α-glucosidase digestive enzymes. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Aqueous extract of Psidium guajava leaves: phenolic compounds and inhibitory potential on digestive enzymes

    Directory of Open Access Journals (Sweden)

    ANDERSON A. SIMÃO

    Full Text Available ABSTRACT Leaves of Psidium guajava L. (guava have been widely used in the popular way for prevention and treatment of various diseases. Thus, the objective of this study was to evaluate the inhibitory potential of leaves aqueous extract from three cultivars of P. guajava (Pedro Sato, Paluma and Século XXI on α-amylase, α-glycosidase, lipase, and trypsin enzymes, in the presence or not of simulated gastric fluid and to determine the content of phenolic compounds by high performance liquid chromatography. All cultivars presented the same composition in phenolic compounds, but in different proportions. The compounds identified are gallic acid, epigallocatechin gallate, syringic acid, o-coumaric acid, resveratrol, quercetin, and catechin (which was the major compound in all the cultivars evaluated. In the absence of simulated gastric fluid, it was observed different inhibitions exercised by the leaves aqueous extracts from three cultivars of P. guajava on each enzyme. In presence of simulated gastric fluid, all cultivars showed increase in the inhibition of lipase and α-glycosidase, and decrease in inhibition of α-amylase and trypsin enzymes. These results indicate that P. guajava leaves aqueous extracts from all cultivars evaluated possess potential of use as an adjuvant in the treatment of obesity and other dyslipidemias.

  18. Aqueous extract of Psidium guajava leaves: phenolic compounds and inhibitory potential on digestive enzymes.

    Science.gov (United States)

    Simão, Anderson A; Marques, Tamara R; Marcussi, Silvana; Corrêa, Angelita D

    2017-01-01

    Leaves of Psidium guajava L. (guava) have been widely used in the popular way for prevention and treatment of various diseases. Thus, the objective of this study was to evaluate the inhibitory potential of leaves aqueous extract from three cultivars of P. guajava (Pedro Sato, Paluma and Século XXI) on α-amylase, α-glycosidase, lipase, and trypsin enzymes, in the presence or not of simulated gastric fluid and to determine the content of phenolic compounds by high performance liquid chromatography. All cultivars presented the same composition in phenolic compounds, but in different proportions. The compounds identified are gallic acid, epigallocatechin gallate, syringic acid, o-coumaric acid, resveratrol, quercetin, and catechin (which was the major compound in all the cultivars evaluated). In the absence of simulated gastric fluid, it was observed different inhibitions exercised by the leaves aqueous extracts from three cultivars of P. guajava on each enzyme. In presence of simulated gastric fluid, all cultivars showed increase in the inhibition of lipase and α-glycosidase, and decrease in inhibition of α-amylase and trypsin enzymes. These results indicate that P. guajava leaves aqueous extracts from all cultivars evaluated possess potential of use as an adjuvant in the treatment of obesity and other dyslipidemias.

  19. Inhibitory activities of Moringa oleifera leaf extract against α-glucosidase enzyme in vitro

    Science.gov (United States)

    Natsir, H.; Wahab, A. W.; Laga, A.; Arif, A. R.

    2018-03-01

    Alpha-glucosidase is a key enzyme in the final process of breaking carbohydrates into glucose. Inhibition of α-glucosidase affected more absorption of glucose, so it can reduce hyperglycemia condition. The aims of this study is to determine the effectiveness of inhibition wet and dried Moringa oleifera leaf extract through α-glucosidase activity in vitro. The effectiveness study of inhibition on the activity of α-glucosidase enzyme obtained from white glutinous rice (Oryza sativa glutinosa) was carried out using wet and dried kelor leaf extract of 13% (w/v) with 10 mM α-D-glucopyranoside (PNPG) substrate. A positive control used 1% acarbose and substrate without addition of extract was a negative control. Inhibitory activity was measured using spectrophotometers at a wavelength of 400 nm. The result showed that the inhibition activity against α-glucosidase enzyme of dried leaf extract, wet leaf extract and acarbose was 81,39%, 83,94%, and 95,4%, respectively on pH 7,0. The effectiveness inhibition of the wet Moringa leaf extract was greater than the dried leaf extract. The findings suggest that M. oleifera leaf has the potential to be developed as an alternative food therapy for diabetics.

  20. Antioxidant and Angiotensin-Converting Enzyme Inhibitory Activity of Eucalyptus camaldulensis and Litsea glaucescens Infusions Fermented with Kombucha Consortium.

    Science.gov (United States)

    Gamboa-Gómez, Claudia I; González-Laredo, Rubén F; Gallegos-Infante, José Alberto; Pérez, Mş Del Mar Larrosa; Moreno-Jiménez, Martha R; Flores-Rueda, Ana G; Rocha-Guzmán, Nuria E

    2016-09-01

    Physicochemical properties, consumer acceptance, antioxidant and angiotensin-converting enzyme (ACE) inhibitory activities of infusions and fermented beverages of Eucalyptus camaldulensis and Litsea glaucescens were compared. Among physicochemical parameters, only the pH of fermented beverages decreased compared with the unfermented infusions. No relevant changes were reported in consumer preference between infusions and fermented beverages. Phenolic profile measured by UPLC MS/MS analysis demonstrated significant concentration changes of these compounds in plant infusions and fermented beverages. Fermentation induced a decrease in the concentration required to stabilize 50% of DPPH radical ( i . e . lower IC 50 ). Additionally, it enhanced the antioxidant activity measured by the nitric oxide scavenging assay (14% of E. camaldulensis and 49% of L. glaucescens ); whereas relevant improvements in the fermented beverage were not observed in the lipid oxidation assay compared with unfermented infusions. The same behaviour was observed in the inhibitory activity of ACE; however, both infusions and fermented beverages had lower IC 50 than positive control (captopril). The present study demonstrated that fermentation has an influence on the concentration of phenolics and their potential bioactivity. E. camaldulensis and L. glaucescens can be considered as natural sources of biocompounds with antihypertensive potential used either as infusions or fermented beverages.

  1. Antioxidant and Angiotensin-Converting Enzyme Inhibitory Activity of Eucalyptus camaldulensis and Litsea glaucescens Infusions Fermented with Kombucha Consortium

    Directory of Open Access Journals (Sweden)

    Claudia I. Gamboa-Gómez

    2016-01-01

    Full Text Available Physicochemical properties, consumer acceptance, antioxidant and angiotensin-converting enzyme (ACE inhibitory activities of infusions and fermented beverages of Eucalyptus camaldulensis and Litsea glaucescens were compared. Among physicochemical parameters, only the pH of fermented beverages decreased compared with the unfermented infusions. No relevant changes were reported in consumer preference between infusions and fermented beverages. Phenolic profi le measured by UPLC MS/MS analysis demonstrated significant concentration changes of these compounds in plant infusions and fermented beverages. Fermentation induced a decrease in the concentration required to stabilize 50 % of DPPH radical (i.e. lower IC50. Additionally, it enhanced the antioxidant activity measured by the nitric oxide scavenging assay (14 % of E. camaldulensis and 49 % of L. glaucescens; whereas relevant improvements in the fermented beverage were not observed in the lipid oxidation assay compared with unfermented infusions. The same behaviour was observed in the inhibitory activity of ACE; however, both infusions and fermented beverages had lower IC50 than positive control (captopril. The present study demonstrated that fermentation has an influence on the concentration of phenolics and their potential bioactivity. E. camaldulensis and L. glaucescens can be considered as natural sources of biocompounds with antihypertensive potential used either as infusions or fermented beverages.

  2. Short communication: Effect of casein haplotype on angiotensin-converting enzyme inhibitory and antioxidant capacities of milk casein from Italian Holstein cows before and following in vitro digestion with gastrointestinal enzymes.

    Science.gov (United States)

    Perna, Annamaria; Simonetti, Amalia; Gambacorta, Emilio

    2016-09-01

    The aim of this work was to investigate the effect of casein haplotype (αS1, β, and κ) on antioxidative and angiotensin-converting enzyme (ACE) inhibitory capacities of milk casein from Italian Holstein cows before and following in vitro digestion with gastrointestinal enzymes. The antioxidant capacity was measured using 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid and ferric-reducing antioxidant power assays, whereas ACE inhibition was determined by ACE-inhibitory assay. The ACE-inhibitory and antioxidant capacities of milk casein increased during in vitro gastrointestinal digestion. Casein haplotype significantly influenced the antioxidative and ACE-inhibitory capacities of digested casein. In particular, BB-A(2)A(1)-AA casein and BB-A(1)A(1)-AA casein showed the highest ACE-inhibitory capacity, BB-A(2)A(2)-AA casein showed the highest antioxidant capacity, whereas BB-A(2)A(2)-BB casein showed the lowest biological capacity. To date, few studies have been done on the effect of casein haplotype on biological capacity of milk casein, thus the present study sets the basis for a new knowledge that could lead to the production of milk with better nutraceutical properties. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  3. Novel angiotensin-converting enzyme (ACE) inhibitory peptides derived from boneless chicken leg meat.

    Science.gov (United States)

    Terashima, Masaaki; Baba, Takako; Ikemoto, Narumi; Katayama, Midori; Morimoto, Tomoko; Matsumura, Saki

    2010-06-23

    Four peptides that inhibit angiotensin-converting enzyme (ACE) were separated from the hydorlysate of boneless chicken leg meat digested with artificial gastric juice (pepsin). Two peptides were identified as the peptides encrypted in myosin heavy chain. The peptide P1 (MNVKHWPWMK) corresponds to the amino acid sequence from amino acids 825 to 834 of myosin heavy chain, and the peptide P4 (VTVNPYKWLP) corresponds to the amino acid sequence from amino acids 125 to 135 of myosin heavy chain. They are novel ACE inhibitory peptides derived from chicken, and IC(50) values of P1 and P4 were determined as 228 and 5.5 microM, respectively. Although these values were much larger than 0.022 microM for captopril, a typical synthetic ACE inhibitor, they are comparable to IC(50) values reported for various ACE inhibitory peptides derived from foods. Because the peptide P4 has a relatively low IC(50) value, it is a good starting substance for designing food supplements for hypertensive patients.

  4. Inhibitory effects of kale ingestion on metabolism by cytochrome P450 enzymes in rats.

    Science.gov (United States)

    Yamasaki, Izumi; Yamada, Masayoshi; Uotsu, Nobuo; Teramoto, Sachiyuki; Takayanagi, Risa; Yamada, Yasuhiko

    2012-01-01

    Kale (Brassica oleracea L. var acephala DC) is a leafy green vegetable belonging to the cabbage family (Brassicaceae) that contains a large amount of health-promoting phytochemicals. There are any reports about the effects of kale ingestion on the chemoprevention function and mechanism, but the interactions between kale and drugs have not been researched. We investigated the effects of kale intake on cytochrome P450 (CYP) metabolism by using cocktail probe drugs, including midazolam (for CYP3A4), caffeine (for CYP1A2), dextromethorphan (for CYP2D6), tolbutamide (for CYP2C9), omeprazole (for CYP2C19), and chlorzoxazone (for CYP2E1). Cocktail drugs were administered into rats treated with kale and cabbage (2000 mg/kg) for a week. The results showed that kale intake induced a significant increase in plasma levels and the AUC of midazolam, caffeine, and dextromethorphan. In addition, the plasma concentration and AUC of omeprazole tended to increase. Additionally, no almost differences in the mRNA expression levels of CYP enzymes in the liver were observed. In conclusion, kale ingestion was considered to have an inhibitory effect on the activities of CYP3A4, 1A2, 2D6, and 2C19 for a reason competitive inhibition than inhibitory changes in the mRNA expressions.

  5. Enzyme inhibitory and antioxidant activities of traditional medicinal plants: Potential application in the management of hyperglycemia

    Directory of Open Access Journals (Sweden)

    Gulati Vandana

    2012-06-01

    Full Text Available Abstract Background Traditional Indian and Australian medicinal plant extracts were investigated to determine their therapeutic potential to inhibit key enzymes in carbohydrate metabolism, which has relevance to the management of hyperglycemia and type 2 diabetes. The antioxidant activities were also assessed. Methods The evaluation of enzyme inhibitory activity of seven Australian aboriginal medicinal plants and five Indian Ayurvedic plants was carried out against α-amylase and α-glucosidase. Antioxidant activity was determined by measuring (i the scavenging effect of plant extracts against 2, 2-diphenyl-1-picryl hydrazyl (DPPH and 2, 2′-azinobis-3-ethylbenzothiazoline-6-sulfonate (ABTS and (ii ferric reducing power. Total phenolic and total flavonoid contents were also determined. Results Of the twelve plant extracts evaluated, the highest inhibitory activity against both α-amylase and α-glucosidase enzymes was exerted by Santalum spicatum and Pterocarpus marsupium with IC50 values of 5.43 μg/ml and 0.9 μg/ml, respectively, and 5.16 μg/ml and 1.06 μg/ml, respectively. However, the extracts of Acacia ligulata (IC50 = 1.01 μg/ml, Beyeria leshnaultii (0.39 μg/ml, Mucuna pruriens (0.8 μg/ml and Boerhaavia diffusa (1.72 μg/ml exhibited considerable activity against α-glucosidase enzyme only. The free radical scavenging activity was found to be prominent in extracts of Acacia kempeana, Acacia ligulata followed by Euphorbia drummondii against both DPPH and ABTS. The reducing power was more pronounced in Euphorbia drummondii and Pterocarpus marsupium extracts. The phenolic and flavonoid contents ranged from 0.42 to 30.27 μg/mg equivalent of gallic acid and 0.51 to 32.94 μg/mg equivalent of quercetin, respectively, in all plant extracts. Pearson’s correlation coefficient between total flavonoids and total phenolics was 0.796. Conclusion The results obtained in this study showed that most of the plant extracts

  6. Report: screening of selected medicinal plants for their enzyme inhibitory potential - a validation of their ethnopharmacological uses.

    Science.gov (United States)

    Khuda, Fazli; Iqbal, Zafar; Khan, Ayub; Zakiullah; Shah, Yasar; Khan, Abad

    2014-05-01

    In present study four medicinal plants namely Valeriana wallichii, Xanthium strumarium, Achyranthes aspera and Duchesnea indica belonging to different families were collected in Khyber Pakhtunkhwa province and crude extract and subsequent fractions were analyzed for their inhibitory potential against acetylcholinesterase, butyrylcholinesterase and α-glucosidase enzymes. Valeriana wallichii, Xanthium strumarium and Achyranthes aspera were significantly active against cholinesterases. Chloroform and ethylacetate fractions of Valeriana wallichii exhibited significant activity against acetylcholinesterase (IC50: 61μg/ml) and butyrylcholinesterase enzymes (IC50: 58μg/ml), respectively. Similarly ethylacetate fraction of Achyranthes aspera showed significant activity against acetylcholinesterase (IC50: 61 μg/ml) and butyrylcholinesterase enzymes (IC50: 61 μg/ml), respectively. In case of α-glucosidase enzyme, the chloroform fraction of Xanthium strumarium exhibited significant inhibitory activity (IC50: 72 μg/ml) as compared to the standard compound acarbose (IC50: 483 μg/ml). Duchesnea indica showed no such activities.

  7. Fermentation characteristics and angiotensin I-converting enzyme-inhibitory activity of Lactobacillus helveticus isolate H9 in cow milk, soy milk, and mare milk.

    Science.gov (United States)

    Wang, Jicheng; Li, Changkun; Xue, Jiangang; Yang, Jie; Zhang, Qing; Zhang, Heping; Chen, Yongfu

    2015-06-01

    Lactobacillus helveticus isolate H9 demonstrated high angiotensin I-converting enzyme (ACE)-inhibitory activity in previous research. Here, we evaluated the fermentation characteristics (pH, titratable acidity, free amino nitrogen, and viable bacterial counts), ACE-inhibitory activity, and contents of Val-Pro-Pro (VPP) and Ile-Pro-Pro (IPP) peptides of stored yogurt (4°C for 28 d) fermented by L. helveticus isolate H9 (initially inoculated at 4 concentrations), from cow, mare, and soy milks. During storage, the pH and titratable acidity remained stable in yogurts produced from all milk types and all inoculation concentrations. The viable bacterial counts in all stored yogurts ranged between 10(6.72) and 10(8.59) cfu/g. The highest ACE-inhibitory activity (70.9-74.5%) was achieved at inoculation concentrations of 5×10(6) cfu/mL. The ACE-inhibitory tripeptides VPP and IPP as determined by ultra-performance liquid chromatography-tandem mass spectrometry were not produced in yogurt made from soy milk or mare milk. These evaluations indicate that L. helveticus H9 has good probiotic properties and would be a promising candidate for production of fermented food with probiotic properties. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  8. In vitro caries-inhibitory properties of a silver cermet.

    Science.gov (United States)

    Swift, E J

    1989-06-01

    Recurrent caries is one of the primary causes of failure of dental restorations. One method for reducing the frequency and severity of this problem is the use of fluoride-releasing restorative materials. The glass-ionomer cements are a type of fluoride-releasing material. They have been used extensively in recent years for a variety of clinical applications. However, in comparison with other restorative materials such as amalgam and composite resins, glass ionomers have relatively poor physical properties. Sintering of silver particles to glass-ionomer powder is a means of improving these physical properties. The sintered material is called a silver-glass ionomer or silver cermet. This study examined the in vitro caries-inhibitory potential of a silver cement by means of two methods. First, long-term fluoride release was measured. Second, an artificial caries system was used for evaluation of caries inhibition by cerment restorations in extracted teeth. In comparison with a standard glass-ionomer restorative material, fluoride release from the cermet material was significantly less throughout a 12-month period. The results from the artificial caries system indicated that this decreased fluoride release corresponded with a lesser degree of caries inhibition. Lesions around cermet restorations in both enamel and root surfaces were significantly more severe than those around conventional glass-ionomer restorations. However, in comparison with amalgam and composite resin restorations, the cermet did have some cariostatic activity.

  9. Identification and molecular docking study of novel angiotensin-converting enzyme inhibitory peptides from Salmo salar using in silico methods.

    Science.gov (United States)

    Yu, Zhipeng; Chen, Yang; Zhao, Wenzhu; Li, Jianrong; Liu, Jingbo; Chen, Feng

    2018-01-25

    In order to circumvent some challenges of the classical approach, the in silico method has been applied to the discovery of angiotensin-converting enzyme (ACE) inhibitory peptides from food proteins. In this study, some convenient and efficient in silico tools were utilized to identify novel ACE inhibitory peptides from Salmo salar. Collagen from Salmo salar was digested in silico into hundreds of peptides. Results revealed that tetrapeptides PGAR and IGPR showed potent ACE inhibitory activity, with IC 50 values of 0.598 ± 0.12 and 0.43 ± 0.09 mmol L -1 , respectively. The molecular docking result showed that PGAR and IGPR interact with ACE mostly via hydrogen bonds and attractive charge. Peptide IGPR interacts with Zn + at the ACE active site, showing high inhibitory activity. Interaction with Zn + in ACE may lead to higher inhibitory activity of peptides, and Pi interactions may promote the effect of peptides on ACE. The in silico method can be an effective method to predict potent ACE inhibitory peptides from food proteins. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  10. Identification of Angiotensin I-Converting Enzyme Inhibitory Peptides Derived from Enzymatic Hydrolysates of Razor Clam Sinonovacula constricta

    Directory of Open Access Journals (Sweden)

    Yun Li

    2016-06-01

    Full Text Available Angiotensin I-converting enzyme (ACE inhibitory activity of razor clam hydrolysates produced using five proteases, namely, pepsin, trypsin, alcalase, flavourzyme and proteases from Actinomucor elegans T3 was investigated. Flavourzyme hydrolysate showed the highest level of degree of hydrolysis (DH (45.87% followed by A. elegans T3 proteases hydrolysate (37.84% and alcalase (30.55%. The A. elegans T3 proteases was observed to be more effective in generating small peptides with ACE-inhibitory activity. The 3 kDa membrane permeate of A. elegans T3 proteases hydrolysate showed the highest ACE-inhibitory activity with an IC50 of 0.79 mg/mL. After chromatographic separation by Sephadex G-15 gel filtration and reverse phase-high performance liquid chromatography, the potent fraction was subjected to MALDI/TOF-TOF MS/MS for identification. A novel ACE-inhibitory peptide (VQY was identified exhibiting an IC50 of 9.8 μM. The inhibitory kinetics investigation by Lineweaver-Burk plots demonstrated that the peptide acts as a competitive ACE inhibitor. The razor clam hydrolysate obtained by A. elegans T3 proteases could serve as a source of functional peptides with ACE-inhibitory activity for physiological benefits.

  11. Quantitative Structure-Activity Relationship Modeling Coupled with Molecular Docking Analysis in Screening of Angiotensin I-Converting Enzyme Inhibitory Peptides from Qula Casein Hydrolysates Obtained by Two-Enzyme Combination Hydrolysis.

    Science.gov (United States)

    Lin, Kai; Zhang, Lanwei; Han, Xue; Meng, Zhaoxu; Zhang, Jianming; Wu, Yifan; Cheng, Dayou

    2018-03-28

    In this study, Qula casein derived from yak milk casein was hydrolyzed using a two-enzyme combination approach, and high angiotensin I-converting enzyme (ACE) inhibitory activity peptides were screened by quantitative structure-activity relationship (QSAR) modeling integrated with molecular docking analysis. Hydrolysates (casein presents an excellent source to produce ACE inhibitory peptides.

  12. Analysis and Evaluation of the Inhibitory Mechanism of a Novel Angiotensin-I-Converting Enzyme Inhibitory Peptide Derived from Casein Hydrolysate.

    Science.gov (United States)

    Tu, Maolin; Liu, Hanxiong; Zhang, Ruyi; Chen, Hui; Mao, Fengjiao; Cheng, Shuzhen; Lu, Weihong; Du, Ming

    2018-04-25

    Casein hydrolysates exert various biological activities, and the responsible functional peptides are being identified from them continuously. In this study, the tryptic casein hydrolysate was fractionated by an ultrafiltration membrane (3 kDa), and the peptides were identified by capillary electrophoresis-quadrupole-time-of-flight-tandem mass spectrometry. Meanwhile, in silico methods were used to analyze the toxicity, solubility, stability, and affinity between the peptides and angiotensin-I-converting enzyme (ACE). Finally, a new angiotensin-I-converting enzyme inhibitory (ACEI) peptide, EKVNELSK, derived from α s1 -casein (fragment 35-42) was screened. The half maximal inhibitory concentration value of the peptide is 5.998 mM, which was determined by a high-performance liquid chromatography method. The Lineweaver-Burk plot indicated that this peptide is a mixed-type inhibitor against ACE. Moreover, Discovery Studio 2017 R2 software was adopted to perform molecular docking to propose the potential mechanisms underlying the ACEI activity of the peptide. These results indicated that EKVNELSK is a new ACEI peptide identified from casein hydrolysate.

  13. Angiotensin-I Converting Enzyme (ACE Inhibitory and Anti-Oxidant Activities of Sea Cucumber (Actinopyga lecanora Hydrolysates

    Directory of Open Access Journals (Sweden)

    Raheleh Ghanbari

    2015-12-01

    Full Text Available In recent years, food protein-derived hydrolysates have received considerable attention because of their numerous health benefits. Amongst the hydrolysates, those with anti-hypertensive and anti-oxidative activities are receiving special attention as both activities can play significant roles in preventing cardiovascular diseases. The present study investigated the angiotensin-I converting enzyme (ACE inhibitory and anti-oxidative activities of Actinopyga lecanora (A. lecanora hydrolysates, which had been prepared by alcalase, papain, bromelain, flavourzyme, pepsin, and trypsin under their optimum conditions. The alcalase hydrolysate showed the highest ACE inhibitory activity (69.8% after 8 h of hydrolysis while the highest anti-oxidative activities measured by 2,2-diphenyl 1-1-picrylhydrazyl radical scavenging (DPPH (56.00% and ferrous ion-chelating (FIC (59.00% methods were exhibited after 24 h and 8 h of hydrolysis, respectively. The ACE-inhibitory and anti-oxidative activities displayed dose-dependent trends, and increased with increasing protein hydrolysate concentrations. Moreover, strong positive correlations between angiotensin-I converting enzyme (ACE inhibitory and anti-oxidative activities were also observed. This study indicates that A. lecanora hydrolysate can be exploited as a source of functional food owing to its anti-oxidant as well as anti-hypertension functions.

  14. Yak milk casein as potential precursor of angiotensin I-converting enzyme inhibitory peptides based on in silico proteolysis.

    Science.gov (United States)

    Lin, Kai; Zhang, Lan-Wei; Han, Xue; Xin, Liang; Meng, Zhao-Xu; Gong, Pi-Min; Cheng, Da-You

    2018-07-15

    Yak milk casein was selected as a potential precursor of bioactive peptides based on in silico analysis. Most notable among these are the angiotensin I-converting enzyme (ACE) inhibitory peptides. First, yak milk casein has high homology with cow milk casein by homologous analysis. The potential of yak milk casein for the releasing bioactive peptides was evaluated by determining the frequency of occurrence of fragments with a given activity. Through the BIOPEP database analysis, there are many bioactive peptides in yak milk casein sequences. Then, an in silico proteolysis using single or combined enzymes to obtained ACE inhibitory peptides was investigated. Cytotoxicity analysis using the online toxic prediction tool ToxinPred revealed that all in silico proteolysis derived ACE inhibitory peptides are non-cytotoxic. Overall, the present study highlights a in silico proteolysis approach to assist the yak milk casein releasing ACE inhibitory peptides and provides a guidance for the actual hydrolysis of proteins for the production of bioactive peptides. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. In vitro digestion of purified β-casein variants A(1), A(2), B, and I: effects on antioxidant and angiotensin-converting enzyme inhibitory capacity.

    Science.gov (United States)

    Petrat-Melin, B; Andersen, P; Rasmussen, J T; Poulsen, N A; Larsen, L B; Young, J F

    2015-01-01

    Genetic polymorphisms of bovine milk proteins affect the protein profile of the milk and, hence, certain technological properties, such as casein (CN) number and cheese yield. However, reports show that such polymorphisms may also affect the health-related properties of milk. Therefore, to gain insight into their digestion pattern and bioactive potential, β-CN was purified from bovine milk originating from cows homozygous for the variants A(1), A(2), B, and I by a combination of cold storage, ultracentrifugation, and acid precipitation. The purity of the isolated β-CN was determined by HPLC, variants were verified by mass spectrometry, and molar extinction coefficients at λ=280nm were determined. β-Casein from each of the variants was subjected to in vitro digestion using pepsin and pancreatic enzymes. Antioxidant and angiotensin-converting enzyme (ACE) inhibitory capacities of the hydrolysates were assessed at 3 stages of digestion and related to that of the undigested samples. Neither molar extinction coefficients nor overall digestibility varied significantly between these 4 variants; however, clear differences in digestion pattern were indicated by gel electrophoresis. In particular, after 60min of pepsin followed by 5min of pancreatic enzyme digestion, one ≈4kDa peptide with the N-terminal sequence (106)H-K-E-M-P-F-P-K- was absent from β-CN variant B. This is likely a result of the (122)Ser to (122)Arg substitution in variant B introducing a novel trypsin cleavage site, leading to the changed digestion pattern. All investigated β-CN variants exhibited a significant increase in antioxidant capacity upon digestion, as measured by the Trolox-equivalent antioxidant capacity assay. After 60min of pepsin + 120min of pancreatic enzyme digestion, the accumulated increase in antioxidant capacity was ≈1.7-fold for the 4 β-CN variants. The ACE inhibitory capacity was also significantly increased by digestion, with the B variant reaching the highest inhibitory

  16. Sympatho-inhibitory properties of various AT1 receptor antagonists

    NARCIS (Netherlands)

    Balt, Jippe C.; Mathy, Marie-Jeanne; Pfaffendorf, Martin; van Zwieten, Peter A.

    2002-01-01

    It is well known that angiotensin II (Ang II) can facilitate the effects of sympathetic neurotransmission. In the present study, using various experimental models, we investigated the inhibitory effects of several Ang II subtype 1 receptor (AT1) antagonists on this Ang II-induced facilitation. We

  17. A conformational switch in the inhibitory gamma-subunit of PDE6 upon enzyme activation by transducin.

    Science.gov (United States)

    Granovsky, A E; Artemyev, N O

    2001-11-06

    In response to light, a photoreceptor G protein, transducin, activates cGMP-phosphodiesterase (PDE6) by displacing the inhibitory gamma-subunits (Pgamma) from the enzyme's catalytic sites. Evidence suggests that the activation of PDE6 involves a conformational change of the key inhibitory C-terminal domain of Pgamma. In this study, the C-terminal region of Pgamma, Pgamma-73-85, has been targeted for Ala-scanning mutagenesis to identify the point-to-point interactions between Pgamma and the PDE6 catalytic subunits and to probe the nature of the conformational change. Pgamma mutants were tested for their ability to inhibit PDE6 and a chimeric PDE5-conePDE6 enzyme containing the Pgamma C-terminus-binding site of cone PDE. This analysis has revealed that in addition to previously characterized Ile86 and Ile87, important inhibitory contact residues of Pgamma include Asn74, His75, and Leu78. The patterns of mutant PDE5-conePDE6 enzyme inhibition suggest the interaction between the PgammaAsn74/His75 sequence and Met758 of the cone PDE6alpha' catalytic subunit. This interaction, and the interaction between the PgammaIle86/Ile87 and PDE6alpha'Phe777/Phe781 residues, is most consistent with an alpha-helical structure of the Pgamma C-terminus. The analysis of activation of PDE6 enzymes containing Pgamma mutants with Ala-substituted transducin-contact residues demonstrated the critical role of PgammaLeu76. Accordingly, we hypothesize that the initial step in PDE6 activation involves an interaction of transducin-alpha with PgammaLeu76. This interaction introduces a bend into the alpha-helical structure of the Pgamma C-terminus, allowing transducin-alpha to further twist the C-terminus thereby uncovering the catalytic pocket of PDE6.

  18. Evaluation of phenolic profile, enzyme inhibitory and antimicrobial activities of Nigella sativa L. seed extracts

    Directory of Open Access Journals (Sweden)

    Anela Topcagic

    2017-11-01

    Full Text Available Black cumin (Nigella sativa L. [N.sativa] seed extracts demonstrated numerous beneficial biological effects including, among others, antidiabetic, anticancer, immunomodulatory, antimicrobial, anti-inflammatory, antihypertensive, and antioxidant activity. To better understand the phytochemical composition of N. sativa seeds, methanol seed extracts were analyzed for phenolic acid and flavonoid content. Furthermore, we tested N. sativa methanol, n-hexane, and aqueous seed extracts for their inhibitory activity against butyrylcholinesterase (BChE and catalase (CAT as well as for antimicrobial activity against several bacterial and a yeast strains. The phenolic content of N. sativa was analyzed using ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS. The inhibition of BChE was assessed by modified Ellman’s method, and the inhibition of CAT was determined by monitoring hydrogen peroxide consumption. The extracts were tested against Bacillus subtilis, Staphylococcus aureus, Salmonella enterica, and Escherichia coli using the agar diffusion method. The UHPLC-MS/MS method allowed the identification and quantification of 23 phenolic compounds within 15 minutes. The major components found in N. sativa seed extract were sinapinic acid (7.22 ± 0.73 µg/mg as a phenolic acid and kaempferol (11.74 ± 0.92 µg/mg as a flavonoid. All extracts showed inhibitory activity against BChE, with methanol seed extract demonstrating the highest inhibitory activity (inhibitory concentration 50% [IC50] 79.11 ± 6.06 µg/ml. The methanol seed extract also showed strong inhibitory activity against CAT with an IC50 value of 6.61 ± 0.27 µg/ml. Finally, the methanol extract exhibited considerable inhibitory activity against the tested microbial strains. Overall, this is the first study to investigate the ability of black cumin seed extracts to inhibit CAT. Our results indicate that N. sativa seed can be considered as an effective inhibitor

  19. The inhibitory effect of convulsant agents on the enzyme in brain which inactivates nerveside.

    Science.gov (United States)

    Toh, C C

    1969-07-01

    1. An enzyme which can be extracted from brain inactivates nerveside in the optimum pH range 5.8-7.0.2. The polybasic acids trypan blue and its analogue trypan red, bromphenol blue and its analogue bromthymol blue at concentrations of 0.22 mM and ethylenediaminetetra-acetic acid (EDTA) at a concentration of 1 mM are strong inhibitors of the enzyme.3. Penicillin which is a monobasic carboxylic acid also inhibits the enzyme but only if concentrations as high as 3.6 mM are used. The antibiotic streptomycin which is a basic substance does not inhibit the enzyme.4. Caffeine at a concentration of 7.2 mM only weakly inhibits the enzyme.5. Chymotrypsin and wheat germ acid phosphatase also inactivate nerveside at pH 5.9 and are inhibited by the acidic dyes and penicillin. EDTA inhibits wheat germ phosphatase but activates chymotrypsin.6. Inactivation of nerveside by the brain enzyme and by wheat germ phosphatase is different from the action of chymotrypsin. Nerveside solutions incubated with chymotrypsin completely lose all biological activity whereas if incubation is carried out with either the brain enzyme or wheat germ acid phosphatase a residual biological activity remains even when the concentration of these two enzymes is increased. This residual biological activity is due to a peptide as it is destroyed by chymotrypsin.7. The manner in which nerveside is inactivated by the brain enzyme is uncertain as the preparation of the latter contained phosphodiesterase and protease activities which were similarly inhibited by the acid dyes, penicillin and EDTA.8. Pentylenetetrazole, picrotoxin, strychnine and tetanus toxin do not inhibit the brain enzyme.9. The nerveside-inactivating enzyme is not identical with the Substance P-inactivating enzyme in brain as the former is inhibited by EDTA while the latter is not.

  20. Enzymes inhibitory and radical scavenging potentials of two selected tropical vegetable (Moringa oleifera and Telfairia occidentalis leaves relevant to type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Tajudeen O. Jimoh

    Full Text Available ABSTRACT Moringa oleifera Lam., Moringaceae, and Telfairia occidentalis Hook. f., Curcubitaceae, leaves are two tropical vegetables of medicinal properties. In this study, the inhibitory activities and the radical scavenging potentials of these vegetables on relevant enzymes of type 2-diabetes (α-amylase and α-glucosidase were evaluated in vitro. HPLC-DAD was used to characterize the phenolic constituents and Fe2+-induced lipid peroxidation in rat's pancreas was investigated. Various radical scavenging properties coupled with metal chelating abilities were also determined. However, phenolic extracts from the vegetables inhibited α-amylase, α-glucosidase and chelated the tested metals (Cu2+ and Fe2+ in a concentration-dependent manner. More so, the inhibitory properties of phenolic rich extracts from these vegetables could be linked to their radical scavenging abilities. Therefore, this study may offer a promising prospect for M. oleifera and T. occidentalis leaves as a potential functional food sources in the management of type 2-diabetes mellitus.

  1. Two Novel Bioactive Peptides from Antarctic Krill with Dual Angiotensin Converting Enzyme and Dipeptidyl Peptidase IV Inhibitory Activities.

    Science.gov (United States)

    Ji, Wei; Zhang, Chaohua; Ji, Hongwu

    2017-07-01

    Inhibition of dipeptidyl peptidase IV (DPP-IV) and angiotensin converting enzyme (ACE) are considered useful in managing 2 often associated conditions: diabetes and hypertension. In this study, corolase PP was used to hydrolyze Antarctic krill protein. The hydrolysate (AKH) was isolated by ultrafiltration and purified by size-exclusion chromatography, ion exchange chromatography and reversed-phase high-performance liquid chromatography (RP-HPLC) sequentially. The in vitro inhibitory activities of all AKHs and several fractions obtained against ACE and DPP-IV were assessed. Two peptides, purified with dual-strength inhibitory activity against ACE and DPP-IV, were identified by TOF-MS/MS. Results indicated that not all fractions exhibited dual inhibitory activities of ACE and DPP-IV. The purified peptide Lys-Val-Glu-Pro-Leu-Pro had half-maximal inhibitory concentrations (IC 50 ) of 0.93±0.05 and 0.73±0.04 mg/mL against ACE and DPP-IV, respectively. The other peptide Pro-Ala-Leu had IC 50 values of 0.64±0.05 and 0.88±0.03 mg/mL against ACE and DPP-IV, respectively. This study firstly reported the sequences of dual bioactive peptides from Antarctic krill proteins, further provided new insights into the bioactive peptides responsible for the ACE and DPP-IV inhibitory activities from the Antarctic krill protein hydrolysate to manage hypertension and diabetes. © 2017 Institute of Food Technologists®.

  2. Angiotensin-converting enzyme-inhibitory activity in protein hydrolysates from normal and anthracnose disease-damaged Phaseolus vulgaris seeds.

    Science.gov (United States)

    Hernández-Álvarez, Alan Javier; Carrasco-Castilla, Janet; Dávila-Ortiz, Gloria; Alaiz, Manuel; Girón-Calle, Julio; Vioque-Peña, Javier; Jacinto-Hernández, Carmen; Jiménez-Martínez, Cristian

    2013-03-15

    Bean seeds are an inexpensive source of protein. Anthracnose disease caused by the fungus Colletotrichum lindemuthianum results in serious losses in common bean (Phaseolus vulgaris L.) crops worldwide, affecting any above-ground plant part, and protein dysfunction, inducing the synthesis of proteins that allow plants to improve their stress tolerance. The aim of this study was to evaluate the use of beans damaged by anthracnose disease as a source of peptides with angiotensin-converting enzyme (ACE-I)-inhibitory activity. Protein concentrates from beans spoiled by anthracnose disease and from regular beans as controls were prepared by alkaline extraction and precipitation at isolelectric pH and hydrolysed using Alcalase 2.4 L. The hydrolysates from spoiled beans had ACE-I-inhibitory activity (IC(50) 0.0191 mg protein mL(-1)) and were very similar to those from control beans in terms of ACE-I inhibition, peptide electrophoretic profile and kinetics of hydrolysis. Thus preparation of hydrolysates using beans affected by anthracnose disease would allow for revalorisation of this otherwise wasted product. The present results suggest the use of spoiled bean seeds, e.g. anthracnose-damaged beans, as an alternative for the isolation of ACE-I-inhibitory peptides to be further introduced as active ingredients in functional foods. © 2012 Society of Chemical Industry.

  3. Transepithelial transport of milk-derived angiotensin I-converting enzyme inhibitory peptide with the RLSFNP sequence.

    Science.gov (United States)

    Guo, Yuxing; Gan, Junai; Zhu, Qian; Zeng, Xiaoqun; Sun, Yangying; Wu, Zhen; Pan, Daodong

    2018-02-01

    To exert an antihypertensive effect after oral administration, angiotensin I-converting enzyme (ACE)-inhibitory peptides must remain active after intestinal transport. The purpose of this article is to elucidate the transport permeability and route of ACE-inhibitory peptide Arg-Leu-Ser-Phe-Asn-Pro (RLSFNP) across the intestinal epithelium using Caco-2 cell monolayers. Intact RLSFNP and RLSFNP breakdown fragments F, FNP, SFNP and RLSF were found in RLSFNP transport solution across Caco-2 cell monolayers using ultra-performance liquid chromatography-tandem mass spectrometry. RLSFNP fragments FNP, SFNP and RLSF also contributed to ACE inhibitory effects. Protease inhibitors (bacitracin and leupeptin) and absorption enhancers (sodium glycocholate hydrate, sodium deoxycholate and Na 2 EDTA) improved the transport flux of RLSFNP. A transport inhibitor experiment showed that intact RLSFNP may be transported via the paracellular route. Intact RLSFNP can be transported across the Caco-2 cell monolayers via the paracellular route. Extensive hydrolysis was the chief reason for the low permeability of RLSFNP. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  4. Angiotensin I converting enzyme inhibitory activity and antihypertensive effect in spontaneously hypertensive rats of cobia (Rachycentron canadum) head papain hydrolysate.

    Science.gov (United States)

    Yang, Ping; Jiang, Yuchuan; Hong, Pengzhi; Cao, Wenhong

    2013-06-01

    Cobia head protein hydrolysate (CHPH) with angiotensin I converting enzyme (ACE) inhibitory activity was prepared with papain. The 3 kDa ultrafiltration filtrate CHPH-IV of the hydrolysate exerted a potent ACE inhibitory activity with IC50 being 0.24 mg/mL. The fractions with molecular weight located between 1749 Da and 173 Da represented up 66.96% of CHPH-IV, and those between 494 Da and 173 Da represented up 31.37% of CHPH-IV. It was found that the ACE inhibitory activity of CHPH-IV was intensified from IC50 0.24 mg/mL to 0.17 mg/mL after incubation with gastrointestinal proteases. The CHPH-IV significantly decreased the systolic blood pressure in a dose-dependent manner after oral administration to spontaneously hypertensive rats (SHR) at dose of 150 mg/kg, 600 mg/kg and 1200 mg/kg body weight. These results suggested that CHPH-IV from cobia head protein hydrolysate by papain could serve as a source of peptides with antihypertensive activity in functional food industry.

  5. Hypotensive and Angiotensin-Converting Enzyme Inhibitory Activities of Eisenia fetida Extract in Spontaneously Hypertensive Rats

    Directory of Open Access Journals (Sweden)

    Shumei Mao

    2015-01-01

    Full Text Available Objectives. This study aimed to investigate the antihypertensive effects of an Eisenia fetida extract (EFE and its possible mechanisms in spontaneously hypertensive rats (SHR rats. Methods. Sixteen-week-old SHR rats and Wistar-Kyoto rats (WKY rats were used in this study. Rats were, respectively, given EFE (EFE group, captopril (captopril group, or phosphate-buffered saline (PBS (normal control group and SHR group for 4 weeks. ACE inhibitory activity of EFE in vitro was determined. The systolic blood pressure (SBP and diastolic blood pressure (DBP were measured using a Rat Tail-Cuff Blood Pressure System. Levels of angiotensin II (Ang II, aldosterone (Ald, and 6-keto-prostaglandin F1 alpha (6-keto-PGF1α in plasma were determined by radioimmunoassay, and serum nitric oxide (NO concentration was measured by Griess reagent systems. Results. EFE had marked ACE inhibitory activity in vitro (IC50 = 2.5 mg/mL. After the 4-week drug management, SHR rats in EFE group and in captopril group had lower SBP and DBP, lower levels of Ang II and Ald, and higher levels of 6-keto-PGF1α and NO than the SHR rats in SHR group. Conclusion. These results indicate that EFE has hypotensive effects in SHR rats and its effects might be associated with its ACE inhibitory activity.

  6. Flavor Enhancer From Catfish (Clarias batrachus) Bekasam Powder and Angiotensin-I-Converting Enzyme (ACE) Inhibitory Activity in Various Dishes

    Science.gov (United States)

    Lestari, Yanesti N.; Murwani, Retno; Agustini, Tri W.

    2018-02-01

    Flavor enhancer is characterized by high glutamic acid content and it can be obtained from fermented food such as Bekasam. Fermented food had inhibitory effect on Angiotensin-I-Converting Enzyme (ACE) activity which is advantageous for hypertension. However, such activity was not known to sustain in food system. The aim of this research was to study addition of flavour enhancer from Catfish Bekasam Powder (CBP) in various food systems and to determine the ACE inhibitory (ACEI) activity in the food system. Four food system consisted of carrot, champignon, and chicken meat dishes were boiled in water and added with CBP or MSG. Each food system was added with graded level of CBP (0%; 0.5%; 0.8%; 1.1%; and 1,4%) and for control monosodium glutamate (MSG) was used. ACEI activity in each food system and organoleptic test using multiple comparison differentiation on 15 semi-trained panellists were determined. The results showed that there were fluctuation of ACEI activity in the carrot, champignon, and chicken meat dishes (p=0.017; 0.043; and 0.032). The MSG containing dishes showed the lowest ACEI activity. Addition of graded level of CBP on carrot, champignon, and chicken meat dishes were directly proportional to glutamic acid content but inversely proportional to ACEI activity (pacid content but reduced ACE-inhibitory activity significantly (p<0.05). Comparing CBP to MSG addition in champignon dish revealed that increasing level of CBP increased the flavour preference of the panellists. On the contrary the higher the addition CBP in noodle and chicken meat dishes the worse were the flavour score (p<0.05). It can be concluded that the addition of CBP as flavour enhancer on various dishes can deliver better flavour and ACE-inhibitory activity than the addition of commercial MSG.

  7. Cloning and expression of synthetic genes encoding angiotensin-I converting enzyme (ACE)-inhibitory bioactive peptides in Bifidobacterium pseudocatenulatum.

    Science.gov (United States)

    Losurdo, Luca; Quintieri, Laura; Caputo, Leonardo; Gallerani, Raffaele; Mayo, Baltasar; De Leo, Francesca

    2013-03-01

    A wide range of biopeptides potentially able to lower blood pressure through inhibition of the angiotensin-I converting enzyme (ACE) is produced in fermented foods by proteolytic starter cultures. This work applies a procedure based on recombinant DNA technologies for the synthesis and expression of three ACE-inhibitory peptides using a probiotic cell factory. ACE-inhibitory genes and their pro-active precursors were designed, synthesized by PCR, and cloned in Escherichia coli; after which, they were cloned into the pAM1 E. coli-bifidobacteria shuttle vector. After E. coli transformation, constructs carrying the six recombinant clones were electrotransferred into the Bifidobacterium pseudocatenulatum M115 probiotic strain. Interestingly, five of the six constructs proved to be stable. Their expression was confirmed by reverse transcription PCR. Furthermore, transformed strains displayed ACE-inhibitory activity linearly correlated to increasing amounts of cell-free cellular lysates. In particular, 50 μg of lysates from constructs pAM1-Pro-BP3 and pAM1-BP2 showed a 50% higher ACE-inhibitory activity than that of the controls. As a comparison, addition of 50 ng of Pro-BP1 and Pro-BP3 synthetic peptides to 50 μg of cell-free extracts of B. pseudocatenulatum M115 wild-type strain showed an average of 67% of ACE inhibition; this allowed estimating the amount of the peptides produced by the transformants. Engineering of bifidobacteria for the production of biopeptides is envisioned as a promising cell factory model system. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  8. In vitro inhibitory activities of selected Australian medicinal plant extracts against protein glycation, angiotensin converting enzyme (ACE) and digestive enzymes linked to type II diabetes.

    Science.gov (United States)

    Deo, Permal; Hewawasam, Erandi; Karakoulakis, Aris; Claudie, David J; Nelson, Robert; Simpson, Bradley S; Smith, Nicholas M; Semple, Susan J

    2016-11-04

    There is a need to develop potential new therapies for the management of diabetes and hypertension. Australian medicinal plants collected from the Kuuku I'yu (Northern Kaanju) homelands, Cape York Peninsula, Queensland, Australia were investigated to determine their therapeutic potential. Extracts were tested for inhibition of protein glycation and key enzymes relevant to the management of hyperglycaemia and hypertension. The inhibitory activities were further correlated with the antioxidant activities. Extracts of five selected plant species were investigated: Petalostigma pubescens, Petalostigma banksii, Memecylon pauciflorum, Millettia pinnata and Grewia mesomischa. Enzyme inhibitory activity of the plant extracts was assessed against α-amylase, α-glucosidase and angiotensin converting enzyme (ACE). Antiglycation activity was determined using glucose-induced protein glycation models and formation of protein-bound fluorescent advanced glycation endproducts (AGEs). Antioxidant activity was determined by measuring the scavenging effect of plant extracts against 1, 1-diphenyl-2-picryl hydrazyl (DPPH) and using the ferric reducing anti-oxidant potential assay (FRAP). Total phenolic and flavonoid contents were also determined. Extracts of the leaves of Petalostigma banksii and P. pubescens showed the strongest inhibition of α-amylase with IC 50 values of 166.50 ± 5.50 μg/mL and 160.20 ± 27.92 μg/mL, respectively. The P. pubescens leaf extract was also the strongest inhibitor of α-glucosidase with an IC 50 of 167.83 ± 23.82 μg/mL. Testing for the antiglycation potential of the extracts, measured as inhibition of formation of protein-bound fluorescent AGEs, showed that P. banksii root and fruit extracts had IC 50 values of 34.49 ± 4.31 μg/mL and 47.72 ± 1.65 μg/mL, respectively, which were significantly lower (p < 0.05) than other extracts. The inhibitory effect on α-amylase, α-glucosidase and the antiglycation potential of

  9. Assessment of Enzyme Inhibition: A Review with Examples from the Development of Monoamine Oxidase and Cholinesterase Inhibitory Drugs.

    Science.gov (United States)

    Ramsay, Rona R; Tipton, Keith F

    2017-07-15

    The actions of many drugs involve enzyme inhibition. This is exemplified by the inhibitors of monoamine oxidases (MAO) and the cholinsterases (ChE) that have been used for several pharmacological purposes. This review describes key principles and approaches for the reliable determination of enzyme activities and inhibition as well as some of the methods that are in current use for such studies with these two enzymes. Their applicability and potential pitfalls arising from their inappropriate use are discussed. Since inhibitor potency is frequently assessed in terms of the quantity necessary to give 50% inhibition (the IC 50 value), the relationships between this and the mode of inhibition is also considered, in terms of the misleading information that it may provide. Incorporation of more than one functionality into the same molecule to give a multi-target-directed ligands (MTDLs) requires careful assessment to ensure that the specific target effects are not significantly altered and that the kinetic behavior remains as favourable with the MTDL as it does with the individual components. Such factors will be considered in terms of recently developed MTDLs that combine MAO and ChE inhibitory functions.

  10. Physicochemical Properties and Enzymes Activity Studies in a ...

    African Journals Online (AJOL)

    Soil Physicochemical properties and enzyme concentration were evaluated in soil from a refined-oil contaminated community in Isiukwuato, Abia State three years after the spill. The soil enzymes examined were urease, lipase, oxidase, alkaline and acid phosphatases. Results show a significant (P< 0.05) decrease in the ...

  11. Influence of baking enzymes on antimicrobial activity of five bacteriocin-like inhibitory substances produced by lactic acid bacteria isolated from Lithuanian sourdoughs.

    Science.gov (United States)

    Narbutaite, V; Fernandez, A; Horn, N; Juodeikiene, G; Narbad, A

    2008-12-01

    To evaluate the effect of four different baking enzymes on the inhibitory activity of five bacteriocin-like inhibitory substances (BLIS) produced by lactic acid bacteria (LAB) isolated from Lithuanian sourdoughs. The overlay assay and the Bioscreen methods revealed that the five BLIS exhibited an inhibitory effect against spore germination and vegetative outgrowth of Bacillus subtilis, the predominant species causing ropiness in bread. The possibility that the observed antibacterial activity of BLIS might be lost after treatment with enzymes used for baking purposes was also examined. The enzymes tested; hemicellulase, lipase, amyloglucosidase and amylase had little or no effect on the majority of the antimicrobial activities associated with the five BLIS studied. This study suggests a potential application in the sourdough baking industry for these antimicrobial producing LAB strains in the control of B. subtilis spore germination and vegetative outgrowth.

  12. Chemical constituents, radical scavenging activity and enzyme inhibitory capacity of fruits from Cotoneaster pannosus Franch.

    Science.gov (United States)

    Les, Francisco; López, Víctor; Caprioli, Giovanni; Iannarelli, Romilde; Fiorini, Dennis; Innocenti, Marzia; Bellumori, Maria; Maggi, Filippo

    2017-05-24

    Cotoneaster pannosus (Rosaceae) is a semievergreen shrub, producing globose dark red pomes, native to China and widely used as an ornamental plant all over the world. Despite its extensive cultivation, little information is available on the chemical composition and biological activities of its fruits. In this work, the analysis of the chemical composition of C. pannosus fruits, in terms of phenolic components, carotenoids and ascorbic acid by HPLC/DAD, HPLC/ESI-MS and MS/MS as well as in terms of macro- and micro-nutrients was performed. The fruits proved to be a good source of shikimic acid and caffeoylquinic acids, whereas β-carotene, pelargonidin-3-O glucoside and cyanidin-3,5-rutinoside gave an important contribution to the color of the fruit. Both the polar and apolar fruit extracts showed noteworthy radical scavenger activity and inhibitory effects against monoamine oxidase A (MAO-A), tyrosinase (TYR) and α-glucosidase, making C. pannosus red pomes a promising candidate ingredient in functional foods and dietary supplements.

  13. Inhibitory effect of tributyltin on expression of steroidogenic enzymes in mouse testis.

    Science.gov (United States)

    Kim, Suel-Kee; Kim, Jong-Hoon; Han, Jung Ho; Yoon, Yong-Dal

    2008-01-01

    Tributyltin (TBT) is known to disrupt the development of reproductive organs, thereby reducing fertility. The aim of this study was to evaluate the acute toxicity of TBT on the testicular development and steroid hormone production. Immature (3-week-old) male mice were given a single administration of 25, 50, or 100 mg/kg of TBT by oral gavage. Lumen formation in seminiferous tubule was remarkably delayed, and the number of apoptotic germ cells found inside the tubules was increased in the TBT-exposed animals, whereas no apoptotic signal was observed in interstitial Leydig cells. Reduced serum testosterone concentration and down-regulated expressions of the mRNAs for cholesterol side-chain cleavage enzyme (P450scc), 17alpha -hydroxylase/C(17-20) lyase (P450(17alpha)), 3beta -hydroxysteroid-dehydrogenase (3beta -HSD), and 17beta -hydroxysteroid-dehydrogenase (17beta -HSD) were also observed after TBT exposure. Altogether, these findings demonstrate that exposure to TBT is associated with induced apoptosis of testicular germ cells and inhibition of steroidogenesis by reduction in the expression of steroidogenic enzymes in interstitial Leydig cells. These adverse effects of TBT would cause serious defects in testicular development and function.

  14. Empirical evaluation of inhibitory product, substrate, and enzyme effects during the enzymatic saccharification of lignocellulosic biomass.

    Science.gov (United States)

    Smith, Benjamin T; Knutsen, Jeffrey S; Davis, Robert H

    2010-05-01

    The cellulose hydrolysis kinetics during batch enzymatic saccharification are typified by a rapid initial rate that subsequently decays, resulting in incomplete conversion. Previous studies suggest that changes associated with the solution, substrate, or enzymes may be responsible. In this work, kinetic experiments were conducted to determine the relative magnitude of these effects. Pretreated corn stover (PCS) was used as a lignocellulosic substrate likely to be found in a commercial saccharification process, while Avicel and Kraft lignin were used to create model substrates. Glucose inhibition was observed by spiking the reaction slurry with glucose during initial-rate experiments. Increasing the glucose concentration from 7 to 48 g/L reduced the cellulose conversion rate by 94%. When product sugars were removed using ultrafiltration with a 10 kDa membrane, the glucose-based conversion increased by 9.5%. Reductions in substrate reactivity with conversion were compared directly by saccharifying PCS and Avicel substrates that had been pre-reacted to different conversions. Reaction of substrate with a pre-conversion of 40% resulted in about 40% reduction in the initial rate of saccharification, relative to fresh substrate with identical cellulose concentration. Overall, glucose inhibition and reduced substrate reactivity appear to be dominant factors, whereas minimal reductions of enzyme activity were observed.

  15. In vitro inhibitory effects of plumbagin, the promising antimalarial candidate, on human cytochrome P450 enzymes.

    Science.gov (United States)

    Sumsakul, Wiriyaporn; Chaijaroenkul, Wanna; Na-Bangchang, Kesara

    2015-11-01

    To investigate the propensity of plumbagin to inhibit the three isoforms of human cytochrome P450 (CYP), i.e., CYP1A2, CYP2C19, and CYP3A4 using human liver microsomes in vitro. Inhibitory effects of plumbagin on the three human CYP isoforms were investigated using pooled human liver microsomes. Phenacetin O-deethylation, omeprazole hydroxylation and nifedipine oxidation were used as selective substrates for CYP1A2, CYP2C19 and CYP3A4 activities, respectively. Concentrations of paracetamol, 5-hydroxyomeprazole, and oxidized nifedipine were determined in microsomal incubation mixture using high-performance liquid chromatography. Plumbagin showed significant inhibitory effects on all CYP isoforms, but with the most potent activity on CYP2C19-mediated omeprazole hydroxylation. The IC50 (concentration that inhibits enzyme activity by 50%) values of plumbagin and nootkatone (selective inhibitor) for CYP2C19 were (0.78 ± 0.01) and (27.31 ± 0.66) μM, respectively. The inhibitory activities on CYP1A2-mediated phenacetin O-deethylation and CYP3A4-mediated nifedipine oxidation were moderate. The IC50 values of plumbagin and α-naphthoflavone (selective inhibitor) for CYP1A2 were (1.39 ± 0.01) and (0.02 ± 0.36) μM, respectively. The corresponding IC50 values of plumbagin and ketoconazole (selective inhibitor) for CYP3A4 were (2.37 ± 0.10) and (0.18 ± 0.06) μM, respectively. Clinical relevance of the interference of human drug metabolizing enzymes should be aware of for further development scheme of plumbagin as antimalarial drug when used in combination with other antimalarial drugs which are metabolized by these CYP isoforms. Copyright © 2015 Hainan Medical College. Production and hosting by Elsevier B.V. All rights reserved.

  16. COMPARATIVE STUDY ON ANGIOTENSIN CONVERTING ENZYME INHIBITORY ACTIVITY OF HYDROLYSATE OF MEAT PROTEIN OF INDONESIAN LOCAL LIVESTOCKS

    Directory of Open Access Journals (Sweden)

    J. Jamhari

    2014-10-01

    Full Text Available The experiment was conducted to investigate the angiotensin converting enzyme (ACE inhibitoryactivity of hydrolysate in meat protein of Bali cattle, Kacang goat, native chicken, and local duck. Themeats of Bali cattle, Kacang goat, native chicken, and local duck were used in this study. The meatswere ground using food processor added with aquadest to obtain meat extract. The meat extracts werethen hydrolyzed using protease enzymes to obtain hydrolysate of meat protein. Protein concentration ofmeat extract and hydrolysate of meat protein were determined, and were confirmed by sodium dodecylsulfate - poly acrylamide gel electrophoresis (SDS-PAGE. ACE inhibitory activity of hydrolysate ofmeat protein derived from Bali cattle, Kacang goat, native chicken, and local duck was also determined.The results showed that protein concentration of hydrolysate of meat protein of Bali cattle, Kacang goat,native chicken, and local duck meat was significantly higher than their meat extracts. SDS-PAGEanalysis indicated that hydrolysate of meat protein of Bali cattle, Kacang goat, native chicken, and localduck had more peptides with lower molecular weight, compared to their meat extracts. Hydrolysate ofmeat protein of Bali cattle, Kacang goat, native chicken, and local duck had potencies in inhibiting ACEactivity, so it will potentially reduce blood pressure.

  17. In vitro inhibitory mechanisms and molecular docking of 1'-S-1'-acetoxychavicol acetate on human cytochrome P450 enzymes.

    Science.gov (United States)

    Haque, A K M Mahmudul; Leong, Kok Hoong; Lo, Yoke Lin; Awang, Khalijah; Nagoor, Noor Hasima

    2017-07-15

    The compound, 1'-S-1'-acetoxychavicol acetate (ACA), isolated from the rhizomes of a Malaysian ethno-medicinal plant, Alpinia conchigera Griff. (Zingiberaceae), was previously shown to have potential in vivo antitumour activities. In the development of a new drug entity, potential interactions of the compound with the cytochrome P450 superfamily metabolizing enzymes need to be ascertain. The concomitant use of therapeutic drugs may cause potential drug-drug interactions by decreasing or increasing plasma levels of the administered drugs, leading to a suboptimal clinical efficacy or a higher risk of toxicity. Thus, evaluating the inhibitory potential of a new chemical entity, and to clarify the mechanism of inhibition and kinetics in the various CYP enzymes is an important step to predict drug-drug interactions. This study was designed to assess the potential inhibitory effects of Alpinia conchigera Griff. rhizomes extract and its active constituent, ACA, on nine c-DNA expressed human cytochrome P450s (CYPs) enzymes using fluorescent CYP inhibition assay. The half maximal inhibitory concentration (IC 50 ) of Alpinia conchigera Griff. rhizomes extract and ACA was determined for CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C19, CYP2D6, CYP2E1, CYP3A4 and CYP3A5. A. conchigera extract only moderately inhibits on CYP3A4 (IC 50 = 6.76 ± 1.88µg/ml) whereas ACA moderately inhibits the activities of CYP1A2 (IC 50 = 4.50 ± 0.10µM), CYP2D6 (IC 50 = 7.50 ± 0.17µM) and CYP3A4 (IC 50 = 9.50 ± 0.57µM) while other isoenzymes are weakly inhibited. In addition, mechanism-based inhibition studies reveal that CYP1A2 and CYP3A4 exhibited non-mechanism based inhibition whereas CYP2D6 showed mechanism-based inhibition. Lineweaver-Burk plots depict that ACA competitively inhibited both CYP1A2 and CYP3A4, with a K i values of 2.36 ± 0.03 µM and 5.55 ± 0.06µM, respectively, and mixed inhibition towards CYP2D6 with a K i value of 4.50 ± 0.08µ

  18. Enzyme Inhibitory Radicinol Derivative from Endophytic fungus Bipolaris sorokiniana LK12, Associated with Rhazya stricta

    Directory of Open Access Journals (Sweden)

    Abdul Latif Khan

    2015-07-01

    Full Text Available Endophytes, living inside plant tissues, play an essential role in plant growth and development, whilst producing unique bioactive secondary metabolites. In the current study, the endophytic fungus Bipolaris sorokiniana LK12 was isolated from the leaves of ethno-medicinal and alkaloidal rich Rhazya stricta. The bulk amount of ethyl acetate extract of fungus was subjected to advance column chromatographic techniques, which resulted in the isolation of a new radicinol derivative, bipolarisenol (1. It was found to be a derivative of radicinol. The structure elucidation was carried out by the combined use of 1D and 2D nuclear magnetic resonance, infrared spectroscopy, mass, and UV spectrometric analyses. The bipolarisenol was assessed for its potential role in enzyme inhibition of urease and acetyl cholinesterase (AChE. Results showed that bipolarisenol significantly inhibited the AChE activity with low IC50 (67.23 ± 5.12 µg·mL−1. Bipolarisenol inhibited urease in a dose-dependent manner with high IC50 (81.62 ± 4.61 µg·mL−1. The new compound also showed a moderate anti-lipid peroxidation potential (IC50 = 168.91 ± 4.23 µg·mL−1. In conclusion, endophytes isolated from medicinal plants possess a unique potential to be considered for future drug discovery.

  19. Angiotensin-converting enzyme (ACE) inhibitory potential of standardized Mucuna pruriens seed extract.

    Science.gov (United States)

    Chaudhary, Sushil Kumar; De, Apurba; Bhadra, Santanu; Mukherjee, Pulok K

    2015-01-01

    Mucuna pruriens Linn. (Fabaceae) is a tropical legume, traditionally used for controlling blood pressure. Inhibition of angiotensin-converting enzyme (ACE) is one of the successful strategies for controlling hypertension. The present study evaluated the ACE inhibition potential of the standardized extract of M. pruriens seeds. Standardization of the extract and its fractions were carried out by RP-HPLC method [methanol and 1% v/v acetic acid in water (5:95 v/v)] using levodopa as a marker. The ACE inhibition activity of the extract and fractions was evaluated at different concentrations (20, 40, 60, 80, and 100 µg/mL) using the HPLC-DAD and the UV spectrophotometric method. The liberation of hippuric acid (HA) from hippuryl-L-histidyl-L-leucine (HHL) was estimated in the spectrophotometric method and RP-HPLC assay at 228 nm. Methanol extract and aqueous fraction showed a maximum activity with IC50 values of 38.44 ± 0.90 and 57.07 ± 2.90 µg/mL (RP-HPLC), and 52.68 ± 2.02 and 67.65 ± 2.40 µg/mL (spectrophotometry), respectively. The study revealed that the aqueous extract contains the highest amount of levodopa. Eventually the methanol extract showed highest ACE inhibition activity except levodopa alone. It was further observed that the inhibition was altered with respect to the change in the content of levodopa in the extract. Thus, it can be assumed that levodopa may be responsible for the ACE inhibition activity of M. pruriens seeds. It can be concluded that M. pruriens seed is a potential ACE inhibitor can be explored further as an effective antihypertensive agent.

  20. Effect of low severity dilute-acid pretreatment of barley straw and decreased enzyme loading hydrolysis on the production of fermentable substrates and the release of inhibitory compounds

    NARCIS (Netherlands)

    Panagiotopoulos, I.A.; Lignos, G.D.; Bakker, R.R.C.; Koukios, E.G.

    2012-01-01

    The objective of this work was to investigate the feasibility of combining low severity dilute-acid pretreatment of barley straw and decreased enzyme loading hydrolysis for the high production of fermentable substrates and the low release of inhibitory compounds. For most of the pretreatments at 160

  1. Lytic Polysaccharide Monooxygenases - Studies of Fungal Secretomes and Enzyme Properties

    DEFF Research Database (Denmark)

    Nekiunaite, Laura

    degradation, were also identified upstream the LPMO genes, providing evidence for a co-regulatory mechanism of LPMOs and amylolytic hydrolases. The second part of the PhD thesis is focused on understanding the binding properties of LPMOs to starch and starch mimic substrate. It was shown that LPMOs possessing...... to different substrates at the protein level. It could help to design better enzyme cocktails that increase efficiency of biomass degradation. The secretomes of A. nidulans revealed differences in growth and secretion of enzymes, depending on the type and properties of starches. A common characteristic...... conversion as they produce a wide diversity of degrading enzymes. In the first part of this PhD thesis, the secretomes of the well-known fungus Aspergillus nidulans grown on cereal and legume starches were analyzed. Secretomics is a powerful tool to unravel secretion patterns of fungi and their response...

  2. Production of Angiotensin-I-Converting-Enzyme-Inhibitory Peptides in Fermented Milks Started by Lactobacillus delbrueckii subsp. bulgaricus SS1 and Lactococcus lactis subsp. cremoris FT4

    Science.gov (United States)

    Gobbetti, M.; Ferranti, P.; Smacchi, E.; Goffredi, F.; Addeo, F.

    2000-01-01

    Two fermented milks containing angiotensin-I-converting-enzyme (ACE)-inhibitory peptides were produced by using selected Lactobacillus delbrueckii subsp. bulgaricus SS1 and L. lactis subsp. cremoris FT4. The pH 4.6-soluble nitrogen fraction of the two fermented milks was fractionated by reversed-phase fast-protein liquid chromatography. The fractions which showed the highest ACE-inhibitory indexes were further purified, and the related peptides were sequenced by tandem fast atom bombardment-mass spectrometry. The most inhibitory fractions of the milk fermented by L. delbrueckii subsp. bulgaricus SS1 contained the sequences of β-casein (β-CN) fragment 6-14 (f6-14), f7-14, f73-82, f74-82, and f75-82. Those from the milk fermented by L. lactis subsp. cremoris FT4 contained the sequences of β-CN f7-14, f47-52, and f169-175 and κ-CN f155-160 and f152-160. Most of these sequences had features in common with other ACE-inhibitory peptides reported in the literature. In particular, the β-CN f47-52 sequence had high homology with that of angiotensin-II. Some of these peptides were chemically synthesized. The 50% inhibitory concentrations (IC50s) of the crude purified fractions containing the peptide mixture were very low (8.0 to 11.2 mg/liter). When the synthesized peptides were used individually, the ACE-inhibitory activity was confirmed but the IC50s increased considerably. A strengthened inhibitory effect of the peptide mixtures with respect to the activity of individual peptides was presumed. Once generated, the inhibitory peptides were resistant to further proteolysis either during dairy processing or by trypsin and chymotrypsin. PMID:10966406

  3. Influence of gas-liquid two-phase flow on angiotensin-I converting enzyme inhibitory peptides separation by ultra-filtration.

    Science.gov (United States)

    Charoenphun, Narin; Youravong, Wirote

    2017-01-01

    Membrane fouling is a major problem in ultra-filtration systems and two-phase flow is a promising technique for permeate flux enhancement. The objective of this research was to study the use of an ultra-filtration (UF) system to enrich angiotensin-I converting enzyme (ACE) inhibitory peptides from tilapia protein hydrolysate. To select the most appropriate membrane and operating condition, the effects of membrane molecular weight cut-off (MWCO), transmembrane pressure (TMP) and cross-flow velocity (CFV) on permeate flux and ACE inhibitory peptide separation were studied. Additionally, the gas-liquid two-phase flow technique was applied to investigate its effect on the process capability. The results showed that the highest ACE inhibitory activity was obtained from permeate of the 1 kDa membrane. In terms of TMP and CFV, the permeate flux tended to increase with TMP and CFV. The use of gas-liquid two-phase flow as indicated by shear stress number could reduce membrane fouling and increase the permeate flux up to 42%, depending on shear stress number. Moreover, the use of a shear stress number of 0.039 led to an augmentation in ACE inhibitory activity of permeates. Operating conditions using a shear stress number of 0.039 were recommended for enrichment of ACE inhibitory peptides. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  4. KARAKTERISTIK FISIK, KIMIA, MIKROBIOLOGI WHEY KEFIR DAN AKTIVITASNYA TERHADAP PENGHAMBATAN ANGIOTENSIN CONVERTING ENZYME (ACE [Physical, Chemical and Microbiological Characteristics of Whey Kefir and Its Angiotensin Converting Enzyme (ACE Inhibitory Activity

    Directory of Open Access Journals (Sweden)

    Andi Febrisiantosa*

    2013-12-01

    Full Text Available This study was conducted to evaluate the characteristics of whey-based kefir products and their activity to inhibit the angiotensin converting enzyme (ACE. Kefir was produced by using many types of whey, namely SK: skim milk based kefir (control; WK: gouda cheese whey based kefir; and WKB: commercial whey powder based kefir. The experimental design was a completely randomized design. Each treatment was conducted in triplicates. Kefirs were evaluated for physical and chemical properties (pH, total titratable acidity, viscosity, protein, fat, lactose, and alcohol, microbiological (lactic acid bacteria and yeast population, peptide concentration, ACE inhibition, IC50 and Inhibition Efficiency Ratio (IER. The results showed that the types of whey used for kefir productions significantly affected the physical and chemical characteristics of the products (p0.05. The peptide concentration and ACE inhibitory activity of WK, 1.54±0.02 mg/mL and 73.07±0.91%, was significantly higher (p0.05 from the control (47.19±0.09% per mg/mL but was significantly higher (p<0.05 than that of WKB (45.75±0.18% per mg/mL. This research indicated that whey kefir is a potential source of bioactive peptide for antihypertention agent.

  5. Differential Receptive Field Properties of Parvalbumin and Somatostatin Inhibitory Neurons in Mouse Auditory Cortex.

    Science.gov (United States)

    Li, Ling-Yun; Xiong, Xiaorui R; Ibrahim, Leena A; Yuan, Wei; Tao, Huizhong W; Zhang, Li I

    2015-07-01

    Cortical inhibitory circuits play important roles in shaping sensory processing. In auditory cortex, however, functional properties of genetically identified inhibitory neurons are poorly characterized. By two-photon imaging-guided recordings, we specifically targeted 2 major types of cortical inhibitory neuron, parvalbumin (PV) and somatostatin (SOM) expressing neurons, in superficial layers of mouse auditory cortex. We found that PV cells exhibited broader tonal receptive fields with lower intensity thresholds and stronger tone-evoked spike responses compared with SOM neurons. The latter exhibited similar frequency selectivity as excitatory neurons. The broader/weaker frequency tuning of PV neurons was attributed to a broader range of synaptic inputs and stronger subthreshold responses elicited, which resulted in a higher efficiency in the conversion of input to output. In addition, onsets of both the input and spike responses of SOM neurons were significantly delayed compared with PV and excitatory cells. Our results suggest that PV and SOM neurons engage in auditory cortical circuits in different manners: while PV neurons may provide broadly tuned feedforward inhibition for a rapid control of ascending inputs to excitatory neurons, the delayed and more selective inhibition from SOM neurons may provide a specific modulation of feedback inputs on their distal dendrites. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  6. Inhibitory Effects of Dimethyllirioresinol, Epimagnolin A, Eudesmin, Fargesin, and Magnolin on Cytochrome P450 Enzyme Activities in Human Liver Microsomes

    Directory of Open Access Journals (Sweden)

    Ju-Hyun Kim

    2017-05-01

    Full Text Available Magnolin, epimagnolin A, dimethyllirioresinol, eudesmin, and fargesin are pharmacologically active tetrahydrofurofuranoid lignans found in Flos Magnoliae. The inhibitory potentials of dimethyllirioresinol, epimagnolin A, eudesmin, fargesin, and magnolin on eight major human cytochrome P450 (CYP enzyme activities in human liver microsomes were evaluated using liquid chromatography–tandem mass spectrometry to determine the inhibition mechanisms and inhibition potency. Fargesin inhibited CYP2C9-catalyzed diclofenac 4’-hydroxylation with a Ki value of 16.3 μM, and it exhibited mechanism-based inhibition of CYP2C19-catalyzed [S]-mephenytoin 4’-hydroxylation (Ki, 3.7 μM; kinact, 0.102 min−1, CYP2C8-catalyzed amodiaquine N-deethylation (Ki, 10.7 μM; kinact, 0.082 min−1, and CYP3A4-catalyzed midazolam 1’-hydroxylation (Ki, 23.0 μM; kinact, 0.050 min−1 in human liver microsomes. Fargesin negligibly inhibited CYP1A2-catalyzed phenacetin O-deethylation, CYP2A6-catalyzed coumarin 7-hydroxylation, CYP2B6-catalyzed bupropion hydroxylation, and CYP2D6-catalyzed bufuralol 1’-hydroxylation at 100 μM in human liver microsomes. Dimethyllirioresinol weakly inhibited CYP2C19 and CYP2C8 with IC50 values of 55.1 and 85.0 μM, respectively, without inhibition of CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2D6, and CYP3A4 activities at 100 μM. Epimagnolin A, eudesmin, and magnolin showed no the reversible and time-dependent inhibition of eight major CYP activities at 100 μM in human liver microsomes. These in vitro results suggest that it is necessary to investigate the potentials of in vivo fargesin-drug interaction with CYP2C8, CYP2C9, CYP2C19, and CYP3A4 substrates.

  7. Enzyme

    Science.gov (United States)

    Enzymes are complex proteins that cause a specific chemical change in all parts of the body. For ... use them. Blood clotting is another example of enzymes at work. Enzymes are needed for all body ...

  8. Photosynthetic carboxylating enzymes in Phaeodactylum tricornutum: assay methods and properties

    Energy Technology Data Exchange (ETDEWEB)

    Mukerji, D [Bigelow Lab. for Ocean Sciences, West Boothbay Harbor, ME; Morris, I

    1976-01-01

    Rapid freezing (in liquid nitrogen) of the marine diatom Phaeodactylum tricornutum Bohlin followed by thawing permits a convenient and sensitive measurement of the activities of carboxylating enzymes without the need to prepare a cell-free extract. Using this method, the properties of RuDP and PEP carboxylases have been compared with those assayed in cell-free extracts. The most significant difference was in the Michaelis' constants (K/sub m/'s), the values being lower in the freeze/thaw assay. The absolute rate of carbon-dioxide fixation by the enzymes was less than the rate of photosynthesis by the intact alga. Significantly, the activity of PEP carboxylase was comparable (in some experiments, greater) to that of RuDP carboxylase. The significance of this and the possibility of an enzymatic approach to measurements of marine primary productivity are discussed.

  9. Angiotensin converting enzyme (ACE) inhibitory and antihypertensive activities of protein hydrolysate from meat of Kacang goat (Capra aegagrus hircus).

    Science.gov (United States)

    Mirdhayati, Irdha; Hermanianto, Joko; Wijaya, Christofora H; Sajuthi, Dondin; Arihara, Keizo

    2016-08-01

    The meat of Kacang goat has potential for production of a protein hydrolysate. Functional ingredients from protein hydrolysate of Kacang goat meat were determined by the consistency of angiotensin-converting enzyme (ACE) inhibitory activity and antihypertensive effect. This study examined the potency of Kacang goat protein hydrolysate in ACE inhibition and antihypertensive activity. Protein hydrolysates of Kacang goat meat were prepared using sequential digestion of endo-proteinase and protease complex at several concentrations and hydrolysis times. The highest ACE inhibitory activity resulted from a hydrolysate that was digested for 4 h with 5 g kg(-1) of both enzymes. An ACE inhibitory peptide was purified and a novel peptide found with a sequence of Phe-Gln-Pro-Ser (IC50 value of 27.0 µmol L(-1) ). Both protein hydrolysates and a synthesised peptide (Phe-Gln-Pro-Ser) demonstrated potent antihypertensive activities in spontaneously hypertensive rats. Protein hydrolysate of Kacang goat meat produced by sequential digestion with endo-proteinase and protease complex has great potential as a functional ingredient, particularly as an antihypertensive agent. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  10. Human gut endogenous proteins as a potential source of angiotensin-I-converting enzyme (ACE-I)-, renin inhibitory and antioxidant peptides.

    Science.gov (United States)

    Dave, Lakshmi A; Hayes, Maria; Montoya, Carlos A; Rutherfurd, Shane M; Moughan, Paul J

    2016-02-01

    It is well known that endogenous bioactive proteins and peptides play a substantial role in the body's first line of immunological defence, immune-regulation and normal body functioning. Further, the peptides derived from the luminal digestion of proteins are also important for body function. For example, within the peptide database BIOPEP (http://www.uwm.edu.pl/biochemia/index.php/en/biopep) 12 endogenous antimicrobial and 64 angiotensin-I-converting enzyme (ACE-I) inhibitory peptides derived from human milk and plasma proteins are listed. The antimicrobial peptide database (http://aps.unmc.edu/AP/main.php) lists over 111 human host-defence peptides. Several endogenous proteins are secreted in the gut and are subject to the same gastrointestinal digestion processes as food proteins derived from the diet. The human gut endogenous proteins (GEP) include mucins, serum albumin, digestive enzymes, hormones, and proteins from sloughed off epithelial cells and gut microbiota, and numerous other secreted proteins. To date, much work has been carried out regarding the health altering effects of food-derived bioactive peptides but little attention has been paid to the possibility that GEP may also be a source of bioactive peptides. In this review, we discuss the potential of GEP to constitute a gut cryptome from which bioactive peptides such as ACE-I inhibitory, renin inhibitory and antioxidant peptides may be derived. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Antihypertensive Effects, Molecular Docking Study, and Isothermal Titration Calorimetry Assay of Angiotensin I-Converting Enzyme Inhibitory Peptides from Chlorella vulgaris.

    Science.gov (United States)

    Xie, Jingli; Chen, Xujun; Wu, Junjie; Zhang, Yanyan; Zhou, Yan; Zhang, Lujia; Tang, Ya-Jie; Wei, Dongzhi

    2018-02-14

    The aim of this work is to explore angiotensin I-converting enzyme (ACE) inhibitory peptides from Chlorella vulgaris (C. vulgaris) and discover the inhibitory mechanism of the peptides. After C. vulgaris proteins were gastrointestinal digested in silico, several ACE inhibitory peptides with C-terminal tryptophan were screened. Among them, two novel noncompetitive ACE inhibitors, Thr-Thr-Trp (TTW) and Val-His-Trp (VHW), exhibited the highest inhibitory activity indicated by IC 50 values 0.61 ± 0.12 and 0.91 ± 0.31 μM, respectively. Both the peptides were demonstrated stable against gastrointestinal digestion and ACE hydrolysis. The peptides were administrated to spontaneously hypertensive rats (SHRs) in the dose 5 mg/kg body weight, and VHW could decrease 50 mmHg systolic blood pressure of SHRs (p < 0.05). Molecular docking displayed that both TTW and VHW formed six hydrogen bonds with active site pockets of ACE. Besides, isothermal titration calorimetry assay discovered that VHW could form more stable complex with ACE than TTW. Therefore, VHW was an excellent ACE inhibitor.

  12. Short communication: Potential of Fresco-style cheese whey as a source of protein fractions with antioxidant and angiotensin-I-converting enzyme inhibitory activities.

    Science.gov (United States)

    Tarango-Hernández, S; Alarcón-Rojo, A D; Robles-Sánchez, M; Gutiérrez-Méndez, N; Rodríguez-Figueroa, J C

    2015-11-01

    Recently, traditional Mexican Fresco-style cheese production has been increasing, and the volume of cheese whey generated represents a problem. In this study, we investigated the chemical composition of Fresco-style cheese wheys and their potential as a source of protein fractions with antioxidant and angiotensin-I-converting enzyme (ACE)-inhibitory activities. Three samples from Fresco, Panela, and Ranchero cheeses whey were physicochemically characterized. Water-soluble extracts were fractionated to obtain whey fractions with different molecular weights: 10-5, 5-3, 3-1 and wheys. All whey fractions had antioxidant and ACE-inhibitory activities. The 10-5 kDa whey fraction of Ranchero cheese had the highest Trolox equivalent antioxidant capacity (0.62 ± 0.00 mM), and the 3-1 kDa Panela and Fresco cheese whey fractions showed the highest ACE-inhibitory activity (0.57 ± 0.02 and 0.59 ± 0.04 μg/mL 50%-inhibitory concentration values, respectively). These results suggest that Fresco-style cheese wheys may be a source of protein fractions with bioactivity, and thus could be useful ingredients in the manufacture of functional foods with increased nutritional value. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  13. Utilisation of rapeseed protein isolates for production of peptides with angiotensin I-converting enzyme (ACE-inhibitory activity

    Directory of Open Access Journals (Sweden)

    Vioque, Javier

    2004-12-01

    Full Text Available ACE activity is related to increased arterial pressure and coronary diseases. A rapeseed protein isolate was hydrolyzed with the protease Alcalase in order to investigate the possible presence of ACE inhibitory peptides in the resulting hydrolysates. Hydrolysis for 30 min yielded a hydrolysate with the highest ACE inhibitory activity. Two fractions of this hydrolysate obtained by Biogel P2 gel filtration chromatography were used for further purification of ACE inhibitory peptides. Three fractions with ACE inhibitory activity were purified by reverse-phase HPLC of Biogel P2 f ractions. This demonstrates that rapeseed protein hydrolysates represent a good source of ACE inhibitory peptides .La actividad de ECA está relacionada con una presión arterial alta y enfermedades cardíacas. Un aislado proteico de colza se hidrolizó con alcalasa para estudiar la posible presencia de péptidos inhibidores de ECA en el hidrolizado. La hidrólisis durante 30 min produjo el hidrolizado con la mayor actividad inhibidora de ECA. Dos fracciones de este hidrolizado, obtenidas por cromatografía de filtración en gel Biogel P2, se usaron para la purificación de péptidos inhibidores de ECA. Tres fracciones con actividad inhibidora de ECA se purificaron mediante HPLC en fase reversa de las fracciones obtenidas mediante Biogel P2. Esto demuestra que los hidrolizados proteicos de colza representan una buena fuente de péptidos inhibidores de ECA.

  14. Isolation of an Angiotensin I-Converting Enzyme Inhibitory Protein with Antihypertensive Effect in Spontaneously Hypertensive Rats from the Edible Wild Mushroom Leucopaxillus tricolor

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    Xueran Geng

    2015-06-01

    Full Text Available An 86-kDa homodimeric angiotensin I-converting enzyme (ACE inhibitory protein designated as LTP was isolated from fruit bodies of the mushroom Leucopaxillus tricolor. The isolation procedure involved ultrafiltration through a membrane with a molecular weight cutoff of 10-kDa, ion exchange chromatography on Q-Sepharose, and finally fast protein liquid chromatography-gel filtration on Superdex 75. LTP exhibited an IC50 value of 1.64 mg∙mL−1 for its ACE inhibitory activity. The unique N-terminal amino acid sequence of LTP was disclosed by Edman degradation to be DGPTMHRQAVADFKQ. In addition, seven internal sequences of LTP were elucidated by liquid chromatography-tandem mass spectrometry (LC-MS/MS analysis. Results of the Lineweaver-Burk plot suggested that LTP competitively inhibited ACE. Both LTP and the water extract of L. tricolor exhibited a clear antihypertensive effect on spontaneously hypertensive rats.

  15. The impact of fermentation and in vitro digestion on formation angiotensin converting enzyme (ACE) inhibitory peptides from pea proteins.

    Science.gov (United States)

    Jakubczyk, Anna; Karaś, Monika; Baraniak, Barbara; Pietrzak, Marlena

    2013-12-15

    Pea seeds were fermented by Lactobacillus plantarum 299v in monoculture under different time and temperature conditions and the fermented products were digested in vitro under gastrointestinal conditions. After fermentation and digestion ACE inhibitory activity was determined. In all samples after fermentation no ACE inhibitory activity was noted. Potentially antihypertensive peptides were released during in vitro digestion. The highest DH (68.62%) were noted for control sample, although the lowest IC50 value (0.19 mg/ml) was determined for product after 7 days fermentation at 22 °C. The hydrolysate characterised by the highest ACE inhibitory activity was separated on Sephadex G10 and two peptides fractions were obtained. The highest ACE inhibitory activity (IC50=64.04 μg/ml) for the first fraction was noted. This fraction was separated by HPLC and identified by LC-MS/MS and the sequence of peptide derived from pea proteins was determined as KEDDEEEEQGEEE. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Anthraquinone profile, antioxidant and enzyme inhibitory effect of root extracts of eight Asphodeline taxa from Turkey: can Asphodeline roots be considered as a new source of natural compounds?

    Science.gov (United States)

    Zengin, Gokhan; Locatelli, Marcello; Ceylan, Ramazan; Aktumsek, Abdurrahman

    2016-10-01

    Plant-based foods have become attractive for scientists and food producers. Beneficial effects related to their consumption as dietary supplements are due to the presence of natural occurring secondary metabolites. In this context, studies on these products are important for natural and safely food ingredients evaluation. The aim of this study was to evaluate root extract of eight Asphodeline species as antioxidants, enzyme inhibitors and phytochemical content. Spectrophotometric antioxidant and enzyme inhibitory assays were performed. Total phenolic and flavonoids contents as well as the chemical free-anthraquinones profiles were determined using routinely procedure (HPLC-PDA). Data show that Asphodeline roots can be considered as a new source of natural compounds and can be used as a valuable dietary supplement. Some differences related to biological activities can be inferred to other phytochemicals that can be considered in the future for their synergic or competitive activities.

  17. Potential anti-cholinesterase and β-site amyloid precursor protein cleaving enzyme 1 inhibitory activities of cornuside and gallotannins from Cornus officinalis fruits.

    Science.gov (United States)

    Bhakta, Himanshu Kumar; Park, Chan Hum; Yokozawa, Takako; Tanaka, Takashi; Jung, Hyun Ah; Choi, Jae Sue

    2017-07-01

    Cholinesterase (ChE) and β-site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibitors are promising agents for the treatment of Alzheimer's disease (AD). In the present study, we examined the inhibitory activity of seven compounds isolated from the fruits of Cornus officinalis, cornuside, polymeric proanthocyanidins, 1,2,3-tri-O-galloyl-β-D-glucose, 1,2,3,6-tetra-O-galloyl-β-D-glucose, tellimagrandin I, tellimagrandin II, and isoterchebin, against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and BACE1. All of the compounds displayed concentration-dependent in vitro inhibitory activity toward the ChEs and BACE1. Among them, tellimagrandin II exhibited the best inhibitory activity toward ChEs, whereas the best BACE1 inhibitor was 1,2,3,6-tetra-O-galloyl-β-D-glucose. Isoterchebin and polymeric proanthocyanidins were also significant ChE inhibitors. The kinetic and docking studies demonstrated that all compounds interacted with both the catalytic active sites and the peripheral anionic sites of the ChEs and BACE1. Tellimagrandin II, isoterchebin, and the polymeric proanthocyanidins exhibited concentration-dependent inhibition of peroxynitrite-mediated protein tyrosine nitration. In conclusion, we identified significant ChE and BACE1 inhibitors from Corni Fructus that could have value as new multi-targeted compounds for anti-AD agents.

  18. Identification of novel dipeptidyl peptidase-IV and angiotensin-I-converting enzyme inhibitory peptides from meat proteins using in silico analysis.

    Science.gov (United States)

    Lafarga, Tomas; O'Connor, Paula; Hayes, Maria

    2014-09-01

    Angiotensin-I-converting enzyme (ACE-I, EC 3.4.15.1), renin (EC 3.4.23.15), and dipeptidyl peptidase-IV (DPP-IV, EC 3.4.14.5) play key roles in the control of hypertension and the development of type-2 diabetes and other diseases associated with metabolic syndrome. The aim of this work was to utilize known in silico methodologies, peptide databases and software including ProtParam (http://web.expasy.org/protparam/), Basic Local Alignment Tool (BLAST), ExPASy PeptideCutter (http://web.expasy.org/peptide_cutter/) and BIOPEP (http://www.uwm.edu.pl/biochemia/index.php/pl/biopep) to assess the release of potentially bioactive DPP-IV, renin and ACE-I inhibitory peptides from bovine and porcine meat proteins including hemoglobin, collagen and serum albumin. These proteins were chosen as they are found commonly in meat by-products such as bone, blood and low-value meat cuts. In addition, the bioactivities of identified peptides were confirmed using chemical synthesis and in vitro bioassays. The concentration of peptide required to inhibit the activity of ACE-I and DPP-IV by 50% was determined for selected, active peptides. Novel ACE-I and DPP-IV inhibitory peptides were identified in this study using both in silico analysis and a literature search to streamline enzyme selection for peptide production. These novel peptides included the ACE-I inhibitory tri-peptide Ile-Ile-Tyr and the DPP-IV inhibitory tri-peptide Pro-Pro-Leu corresponding to sequences f (182-184) and f (326-328) of both porcine and bovine serum albumin which can be released following hydrolysis with the enzymes papain and pepsin, respectively. This work demonstrates that meat proteins are a suitable resource for the generation of bioactive peptides and further demonstrates the usefulness of in silico methodologies to streamline identification and generation of bioactive peptides. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Inhibitory effects of black pepper (Piper nigrum) extracts and compounds on human tumor cell proliferation, cyclooxygenase enzymes, lipid peroxidation and nuclear transcription factor-kappa-B.

    Science.gov (United States)

    Liu, Yunbao; Yadev, Vivek R; Aggarwal, Bharat B; Nair, Muraleedharan G

    2010-08-01

    Black pepper (Piper nigrum) and hot pepper (Capsicum spp.) are widely used in traditional medicines. Although hot Capsicum spp. extracts and its active principles, capsaicinoids, have been linked with anticancer and anti-inflammatory activities, whether black pepper and its active principle exhibit similar activities is not known. In this study, we have evaluated the antioxidant, anti-inflammatory and anticancer activities of extracts and compounds from black pepper by using proinflammatory transcription factor NF-kappaB, COX-1 and -2 enzymes, human tumor cell proliferation and lipid peroxidation (LPO). The capsaicinoids, the alkylamides, isolated from the hot pepper Scotch Bonnet were also used to compare the bioactivities of alkylamides and piperine from black pepper. All compounds derived from black pepper suppressed TNF-induced NF-kappaB activation, but alkyl amides, compound 4 from black pepper and 5 from hot pepper, were most effective. The human cancer cell proliferation inhibitory activities of piperine and alklyl amides in Capsicum and black pepper were dose dependant. The inhibitory concentrations 50% (IC50) of the alklylamides were in the range 13-200 microg/mL. The extracts of black pepper at 200 microg/mL and its compounds at 25 microg/mL inhibited LPO by 45-85%, COX enzymes by 31-80% and cancer cells proliferation by 3.5-86.8%. Overall, these results suggest that black pepper and its constituents like hot pepper, exhibit anti-inflammatory, antioxidant and anticancer activities.

  20. Synthesis and enzyme inhibitory studies of some new N-alkylated/aralkylated N-(4-ethoxyphenyl)-2,3-drobenzo-(1,4)-dioxin-6-sulfonamides

    International Nuclear Information System (INIS)

    Abbasi, M.A.; Islam, M.; Rehman, A.U.; Siddiqui, S.Z.

    2016-01-01

    The research endeavor was aimed to synthesize N-alkyl/aralkylated-N-(4-ethoxyphenyl)-2,3-dihydrobenzo-(1,4)-dioxine-6 sulfonamides and to evaluate their enzyme inhibitory potential. The target molecules were synthesized in two steps. The first step involved the reaction of 4-ethoxyaniline (1) with N-2,3-dihydrobenzo(1,4)-dioxin-6-sulfonyl chloride (2) under dynamic pH control maintained by 10% aqueous Na/sub 2/CO/sub 3/ to yield N-(4-ethoxyphenyl)-2,3-dihydrobenzo-(1,4)-dioxine-6-sulfonamide (3). In second step parent compound 3 was reacted with various alkyl/aralkyl halides (4a-l) in N,N'-dimethylformamide and catalytic amount of lithium hydride to accomplish some new N-alkyl/aralkylated-N-(4-ethoxyphenyl)-2,3-dihydrobenzo-(1,4)-dioxine-6 sulfonamides (5a-l). Probable structures of the synthesized compounds were characterized by contemporary spectral techniques i.e. IR, 1H-NMR and EIMS and were finally evaluated for enzyme inhibitory potential against a-glucosidase and urease. The synthesized compounds exhibited moderate to weak therapeutic potential throughout the series. (author)

  1. Abscisic Acid Induced Changes in Production of Primary and Secondary Metabolites, Photosynthetic Capacity, Antioxidant Capability, Antioxidant Enzymes and Lipoxygenase Inhibitory Activity of Orthosiphon stamineus Benth.

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    Mohd Hafiz Ibrahim

    2013-07-01

    Full Text Available An experiment was conducted to investigate and distinguish the relationships in the production of total phenolics, total flavonoids, soluble sugars, H2O2, O2−, phenylalanine ammonia lyase (PAL activity, leaf gas exchange, antioxidant activity, antioxidant enzyme activity [ascorbate peroxidase (APX, catalase (CAT, superoxide dismutase (SOD and Lipoxygenase inhibitory activity (LOX] under four levels of foliar abscisic acid (ABA application (0, 2, 4, 6 µM for 15 weeks in Orthosiphon stamineus Benth. It was found that the production of plant secondary metabolites, soluble sugars, antioxidant activity, PAL activity and LOX inhibitory activity was influenced by foliar application of ABA. As the concentration of ABA was increased from 0 to 6 µM the production of total phenolics, flavonoids, sucrose, H2O2, O2−, PAL activity and LOX inhibitory activity was enhanced. It was also observed that the antioxidant capabilities (DPPH and ORAC were increased. This was followed by increases in production of antioxidant enzymes APX, CAT and SOD. Under high application rates of ABA the net photosynthesis and stomatal conductance was found to be reduced. The production of primary and secondary metabolites displayed a significant positive relationship with H2O2 (total phenolics, r2 = 0.877; total flavonoids, r2 = 0.812; p ≤ 0.05 and O2− (total phenolics, r2 = 0.778; total flavonoids, r2 = 0.912; p ≤ 0.05. This indicated that increased oxidative stress at high application rates of ABA, improved the production of phytochemicals.

  2. Angiotensin I-Converting-Enzyme-Inhibitory and Antibacterial Peptides from Lactobacillus helveticus PR4 Proteinase-Hydrolyzed Caseins of Milk from Six Species

    Science.gov (United States)

    Minervini, F.; Algaron, F.; Rizzello, C. G.; Fox, P. F.; Monnet, V.; Gobbetti, M.

    2003-01-01

    Sodium caseinates prepared from bovine, sheep, goat, pig, buffalo or human milk were hydrolyzed by a partially purified proteinase of Lactobacillus helveticus PR4. Peptides in each hydrolysate were fractionated by reversed-phase fast-protein liquid chromatography. The fractions which showed the highest angiotensin I-converting-enzyme (ACE)-inhibitory or antibacterial activity were sequenced by mass spectrum and Edman degradation analyses. Various ACE-inhibitory peptides were found in the hydrolysates: the bovine αS1-casein (αS1-CN) 24-47 fragment (f24-47), f169-193, and β-CN f58-76; ovine αS1-CN f1-6 and αS2-CN f182-185 and f186-188; caprine β-CN f58-65 and αS2-CN f182-187; buffalo β-CN f58-66; and a mixture of three tripeptides originating from human β-CN. A mixture of peptides with a C-terminal sequence, Pro-Gly-Pro, was found in the most active fraction of the pig sodium caseinate hydrolysate. The highest ACE-inhibitory activity of some peptides corresponded to the concentration of the ACE inhibitor (S)-N-(1-[ethoxycarbonyl]-3-phenylpropyl)-ala-pro maleate (enalapril) of 49.253 μg/ml (100 μmol/liter). Several of the above sequences had features in common with other ACE-inhibitory peptides reported in the literature. The 50% inhibitory concentration (IC50) of some of the crude peptide fractions was very low (16 to 100 μg/ml). Some identified peptides were chemically synthesized, and the ACE-inhibitory activity and IC50s were confirmed. An antibacterial peptide corresponding to β-CN f184-210 was identified in human sodium caseinate hydrolysate. It showed a very large spectrum of inhibition against gram-positive and -negative bacteria, including species of potential clinical interest, such as Enterococcus faecium, Bacillus megaterium, Escherichia coli, Listeria innocua, Salmonella spp., Yersinia enterocolitica, and Staphylococcus aureus. The MIC for E. coli F19 was ca. 50 μg/ml. Once generated, the bioactive peptides were resistant to further

  3. β-Citronellol, an alcoholic monoterpene with inhibitory properties on the contractility of rat trachea

    Directory of Open Access Journals (Sweden)

    T.B. Vasconcelos

    2016-01-01

    Full Text Available β-Citronellol is an alcoholic monoterpene found in essential oils such Cymbopogon citratus (a plant with antihypertensive properties. β-Citronellol can act against pathogenic microorganisms that affect airways and, in virtue of the popular use of β-citronellol-enriched essential oils in aromatherapy, we assessed its pharmacologic effects on the contractility of rat trachea. Contractions of isolated tracheal rings were recorded isometrically through a force transducer connected to a data-acquisition device. β-Citronellol relaxed sustained contractions induced by acetylcholine or high extracellular potassium, but half-maximal inhibitory concentrations (IC50 for K+-elicited stimuli were smaller than those for cholinergic contractions. It also inhibited contractions induced by electrical field stimulation or sodium orthovanadate with pharmacologic potency equivalent to that seen against acetylcholine-induced contractions. When contractions were evoked by selective recruitment of Ca2+ from the extracellular medium, β-citronellol preferentially inhibited contractions that involved voltage-operated (but not receptor-operated pathways. β-Citronellol (but not verapamil inhibited contractions induced by restoration of external Ca2+ levels after depleting internal Ca2+ stores with the concomitant presence of thapsigargin and recurrent challenge with acetylcholine. Treatment of tracheal rings with L-NAME, indomethacin or tetraethylammonium did not change the relaxing effects of β-citronellol. Inhibition of transient receptor potential vanilloid subtype 1 (TRPV1 or transient receptor potential ankyrin 1 (TRPA1 receptors with selective antagonists caused no change in the effects of β-citronellol. In conclusion, β-citronellol exerted inhibitory effects on rat tracheal rings, with predominant effects on contractions that recruit Ca2+ inflow towards the cytosol by voltage-gated pathways, whereas it appears less active against contractions elicited by

  4. Angiotensin-converting enzyme inhibitory activity of Lactobacillus helveticus strains from traditional fermented dairy foods and antihypertensive effect of fermented milk of strain H9.

    Science.gov (United States)

    Chen, Yongfu; Liu, Wenjun; Xue, Jiangang; Yang, Jie; Chen, Xia; Shao, Yuyu; Kwok, Lai-yu; Bilige, Menghe; Mang, Lai; Zhang, Heping

    2014-11-01

    Hypertension is a major global health issue which elevates the risk of a large world population to chronic life-threatening diseases. The inhibition of angiotensin-converting enzyme (ACE) is an effective target to manage essential hypertension. In this study, the fermentation properties (titratable acidity, free amino nitrogen, and fermentation time) and ACE-inhibitory (ACEI) activity of fermented milks produced by 259 Lactobacillus helveticus strains previously isolated from traditional Chinese and Mongolian fermented foods were determined. Among them, 37 strains had an ACEI activity of over 50%. The concentrations of the antihypertensive peptides, Ile-Pro-Pro and Val-Pro-Pro, were further determined by ultra performance liquid chromatography with quadrupole-time-of-flight mass spectrometry. The change of ACEI activity of the fermented milks of 3 strains exhibiting the highest ACEI activity upon gastrointestinal protease treatment was assayed. Fermented milks produced by strain H9 (IMAU60208) had the highest in vitro ACEI activity (86.4 ± 1.5%), relatively short fermentation time (7.5 h), and detectable Val-Pro-Pro (2.409 ± 0.229 µM) and Ile-Pro-Pro (1.612 ± 0.114 µM) concentrations. Compared with the control, a single oral dose of H9-fermented milk significantly attenuated the systolic, diastolic, and mean blood pressure of spontaneously hypertensive rats (SHR) by 15 to 18 mmHg during the 6 to 12 h after treatment. The long-term daily H9-fermented milk intake over 7 wk exerted significant antihypertensive effect to SHR, but not normotensive rats, and the systolic and diastolic blood pressure were significantly lower, by 12 and 10 mmHg, respectively, compared with the control receiving saline. The feeding of H9-fermented milk to SHR resulted in a significantly higher weight gain at wk 7 compared with groups receiving saline, commercial yogurt, and captopril. Our study identified a novel probiotic L. helveticus strain originated from kurut sampled from Tibet

  5. In Vitro Antioxidant Properties, HIV-1 Reverse Transcriptase and Acetylcholinesterase Inhibitory Effects of Traditional Herbal Preparations Sold in South Africa

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    Johannes Van Staden

    2010-10-01

    Full Text Available The antioxidant potentials for fourteen multipurpose traditional herbal preparations sold in South Africa were determined using the DPPH radical scavenging, ferric reducing power and β-carotene-linoleic acid model system, the anti-HIV-1 reverse transcriptase (RT enzyme inhibitory effects using an ELISA kit and acetylcholinesterase (AChE enzyme inhibition using the microtitre plate assay. Nine of the herbal mixtures (Umzimba omubi, Umuthi wekukhwehlela ne zilonda, Mvusa ukunzi, Umpatisa inkosi, Imbiza ephuzwato, Vusa umzimba, Supreme one hundred, Sejeso herbal mixture Ingwe® and Ingwe® special muti exhibited higher antioxidant potentials, while only four (Imbiza ephuzwato, Ingwe® muthi mixture, Sejeso herbal mixture Ingwe® and African potato extractTM showed potent activity against the RT enzyme. Nine mixtures (Imbiza ephuzwato, Umpatisa inkosi, African potato extractTM, Sejeso herbal mixture Ingwe®, Vusa umzimba; Ingwe® muthi mixture, Ibhubezi™, Lion izifozonke Ingwe® and Ingwe® special muti showed AChE enzyme inhibitory activity greater than 50%. The observed activity exhibited by some of the herbal mixtures gives some credence to the manufacturers’ claims and goes part of the way towards validating their use against certain conditions such as oxidative stress, HIV/AIDS proliferation and some mental conditions. It is however, desirable to carry out further studies to determine the effects of mixing plant species/parts in one mixture on the antioxidant potency as well as isolating active constituents from the herbal mixtures.

  6. Inhibitory effects of astaxanthin, β-cryptoxanthin, canthaxanthin, lutein, and zeaxanthin on cytochrome P450 enzyme activities.

    Science.gov (United States)

    Zheng, Yu Fen; Bae, Soo Hyeon; Kwon, Min Jo; Park, Jung Bae; Choi, Hye Duck; Shin, Wan Gyoon; Bae, Soo Kyung

    2013-09-01

    Astaxanthin, β-cryptoxanthin, canthaxanthin, lutein and zeaxanthin, the major xanthophylls, are widely used in food, medicine, and health care products. To date, no studies regarding the inhibitory effects of these xanthophylls on the nine CYPs isozymes have been reported. This study investigated the reversible and time-dependent inhibitory potentials of five xanthophylls on CYPs activities in vitro. The reversible inhibition results showed that the five compounds had only a weak inhibitory effect on the nine CYPs. Lutein did not inhibit the nine CYPs activities. Astaxanthin weakly inhibited CYP2C19, with an IC₅₀ of 16.2 μM; and β-cryptoxanthin weakly inhibited CYP2C8, with an IC₅₀ of 13.8 μM. In addition, canthaxanthin weakly inhibited CYP2C19 and CYP3A4/5, with IC₅₀ values of 10.9 and 13.9 μM, respectively. Zeaxanthin weakly inhibited CYP3A4/5, with an IC₅₀ of 15.5 μM. However, these IC₅₀ values were markedly greater than the Cmax values reported in humans. No significant IC₅₀ shift was observed in the time-dependent inhibition screening. Based on these observations, it is unlikely that these five xanthophylls from the diet or nutritional supplements alter the pharmacokinetics of drugs metabolized by CYPs. These findings provide some useful information for the safe use of these five xanthophylls in clinical practice. Copyright © 2013. Published by Elsevier Ltd.

  7. Inhibitory effects of Urtica dioica L. root on electrophysiological properties of isolated rabbit atrioventricular node

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    A. Enayati

    2017-11-01

    Full Text Available Background and objectives: The ideal drug for treatment of a wide range of supraventricular arrhythmia hasn't yet been developed. Previous studies have shown antihypertensive and negative inotropic effects of the Urtica dioica L. (nettle. Therefore, the aim of present study is to determine the rate dependent inhibitory effects of ethanol extract of nettle root and investigate the role of adrenoceptors in the anti-arrhythmic mechanism of nettle on the isolated rabbit atrio-ventricular node. Methods: Urtica dioica roots were collected from Gorgan (Golestan, Iran. Male New Zealand rabbits (n=7 were used in all of the experiments. Experimental stimulation protocols (WBCL; Recovery, Facilitation, Fatigue were applied to assess electrophysiological properties of Node. All protocols were repeated in the presence and absence (control of different concentration (0.25-0.5 w/v % of nettle and 1 μM nadolol. Data were shown as Mean±SE, difference between groups statistically were assessed by SPSS software. Results: Nettle (0.5 w/v significantly decreased basic and functional properties of node as WBCL, ERP, FRP, AVCT and magnitude of fatigue (∆AH significantly increased but ∆FRP significantly decreased. In the presence of nadolol (1μM as a nonselective β-blocker, nettle (0.3 mg/L could not repeat its effects on electrophysiological properties of AV-node. Conclusion: The results showed the modifying properties of Urtica dioica root extract. It may be considered as a candidate for the treatment of supraventicular arrhythmias.

  8. Inhibitory and enzyme-kinetic investigation of chelerythrine and lupeol isolated from Zanthoxylum rhoifolium against krait snake venom acetylcholinesterase

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Mustaq, E-mail: mushtaq213@yahoo.com [University of Science and Technology, Bannu, (Pakistan). Department of Biotechnology; Weber, Andrea D.; Zanon, Graciane; Tavares, Luciana de C.; Ilha, Vinicius; Dalcol, Ionara I.; Morel, Ademir F., E-mail: ademirfariasm@gmail.com [Universidade Federal de Santa Maria, RS (Brazil). Dept. de Quimica

    2014-01-15

    The in vitro activity of chelerythrine and lupeol, two metabolites isolated from Zanthoxylum rhoifolium were studied against the venom of the snake Bungarus sindanus (Elapidae). The venom, which is highly toxic to humans, consists mainly by the enzyme acetylcholinesterase (AChE). Both compounds showed activity against the venom, and the alkaloid chelerythrine presented higher activity than did triterpene lupeol. (author)

  9. Inhibitory effect on Streptococcus mutans and mechanical properties of the chitosan containing composite resin

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    Ji-Sun Kim

    2013-02-01

    Full Text Available Objectives This study evaluated the antibacterial effect and mechanical properties of composite resins (LCR, MCR, HCR incorporating chitosan with three different molecular weights (L, Low; M, Medium; H, High. Materials and Methods Streptococcus (S. mutans 100 mL and each chitosan powder were inoculated in sterilized 10 mL Brain-Heart Infusion (BHI solution, and was centrifuged for 12 hr. Absorbance of the supernatent was measured at OD660 to estimate the antibacterial activities of chitosan. After S. mutans was inoculated in the disc shaped chitosan-containing composite resins, the disc was cleansed with BHI and diluted with serial dilution method. S. mutans was spread on Mitis-salivarius bacitracin agar. After then, colony forming unit (CFU was measured to verify the inhibitory effect on S. mutans biofilm. To ascertain the effect on the mechanical properties of composite resin, 3-point bending and Vickers hardness tests were done after 1 and 3 wk water storage, respectively. Using 2-way analysis of variance (ANOVA and Scheffe test, statistical analysis was done with 95% significance level. Results All chitosan powder showed inhibition effect against S. mutans. CFU number in chitosan-containing composite resins was smaller than that of control resin without chitosan. The chitosan containing composite resins did not show any significant difference in flexural strength and Vickers hardness in comparison with the control resin. However, the composite resin, MCR showed a slightly decreased flexural strength and the maximum load than those of control and the other composite resins HCR and LCR. Conclusions LCR and HCR would be recommended as a feasible antibacterial restorative due to its antibacterial nature and mechanical properties.

  10. Investigation of lactic acid bacterial strains for meat fermentation and the product's antioxidant and angiotensin-I-converting-enzyme inhibitory activities.

    Science.gov (United States)

    Takeda, Shiro; Matsufuji, Hisashi; Nakade, Koji; Takenoyama, Shin-Ichi; Ahhmed, Abdulatef; Sakata, Ryoichi; Kawahara, Satoshi; Muguruma, Michio

    2017-03-01

    In the lactic acid bacteria (LAB) strains screened from our LAB collection, Lactobacillus (L.) sakei strain no. 23 and L. curvatus strain no. 28 degraded meat protein and tolerated salt and nitrite in vitro. Fermented sausages inoculated strains no. 23 and no. 28 showed not only favorable increases in viable LAB counts and reduced pH, but also the degradation of meat protein. The sausages fermented with these strains showed significantly higher antioxidant activity than those without LAB or fermented by each LAB type strain. Angiotensin-I-converting-enzyme (ACE) inhibitory activity was also significantly higher in the sausages fermented with strain no. 23 than in those fermented with the type strain. Higher ACE inhibitory activity was also observed in the sausages fermented with strain no. 28, but did not differ significantly from those with the type strain. An analysis of the proteolysis and degradation products formed by each LAB in sausages suggested that those bioactivities yielded fermentation products such as peptides. Therefore, LAB starters that can adequately ferment meat, such as strains no. 23 and no. 28, should contribute to the production of bioactive compounds in meat products. © 2016 Japanese Society of Animal Science.

  11. Both dioscorin, the tuber storage protein of yam (Dioscorea alata cv. Tainong No. 1), and its peptic hydrolysates exhibited angiotensin converting enzyme inhibitory activities.

    Science.gov (United States)

    Hsu, Feng-Lin; Lin, Yaw-Huei; Lee, Mei-Hsien; Lin, Chien-Liang; Hou, Wen-Chi

    2002-10-09

    Dioscorin, the tuber storage protein of yam (Dioscorea alata cv. Tainong No. 1), was purified to homogeneity by DE-52 ion-exchange chromatography. This purified dioscorin was shown by spectrophotometric methods to inhibit angiotensin converting enzyme (ACE) in a dose-dependent manner (12.5-750 microg, respectively, 20.83-62.5% inhibitions) using N-[3-(2-furyl)acryloyl]-Phe-Gly-Gly (FAPGG) as substrates. The 50% inhibition (IC(50)) of ACE activity was 6.404 microM dioscorin (250 microg corresponding to 7.81 nmol) compared to that of 0.00781 microM (0.0095 nmol) for captopril. The commercial bovine serum albumin and casein (bovine milk) showed less ACE inhibitory activity. The use of qualitative TLC also showed dioscorin as ACE inhibitors. Dioscorin showed mixed noncompetitive inhibitions against ACE; when 31.25 microg of dioscorin (0.8 microM) was added, the apparent inhibition constant (K(i)) was 2.738 microM. Pepsin was used for dioscorin hydrolysis at 37 degrees C for different times. It was found that the ACE inhibitory activity was increased from 51.32% to about 75% during 32 h hydrolysis. The smaller peptides were increased with increasing pepsin hydrolytic times. Dioscorin and its hydrolysates might be a potential for hypertension control when people consume yam tuber.

  12. Synthesis, enzyme inhibitory kinetics mechanism and computational study of N-(4-methoxyphenethyl-N-(substituted-4-methylbenzenesulfonamides as novel therapeutic agents for Alzheimer’s disease

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    Muhammad Athar Abbasi

    2018-06-01

    Full Text Available The present study comprises the synthesis of a new series of sulfonamides derived from 4-methoxyphenethylamine (1. The synthesis was initiated by the reaction of 1 with 4-methylbenzenesulfonyl chloride (2 in aqueous sodium carbonate solution at pH 9 to yield N-(4-methoxyphenethyl-4-methylbenzensulfonamide (3.This parent molecule 3 was subsequently treated with various alkyl/aralkyl halides, (4a–j, using N,N-dimethylformamide (DMF as solvent and LiH as activator to produce a series of new N-(4-methoxyphenethyl-N-(substituted-4-methylbenzenesulfonamides (5a–j. The structural characterization of these derivatives was carried out by spectroscopic techniques like IR, 1H-NMR, and 13C-NMR. The elemental analysis data was also coherent with spectral data of these molecules. The inhibitory effects on acetylcholinesterase and DPPH were evaluated and it was observed that N-(4-Methoxyphenethyl-4-methyl-N-(2-propylbenzensulfonamide (5c showed acetylcholinesterase inhibitory activity 0.075 ± 0.001 (IC50 0.075 ± 0.001 µM comparable to Neostigmine methylsulfate (IC50 2.038 ± 0.039 µM.The docking studies of synthesized ligands 5a–j were also carried out against acetylcholinesterase (PDBID 4PQE to compare the binding affinities with IC50 values. The kinetic mechanism analyzed by Lineweaver-Burk plots demonstrated that compound (5c inhibits the acetylcholinesterase competitively to form an enzyme inhibitor complex. The inhibition constants Ki calculated from Dixon plots for compound (5c is 2.5 µM. It was also found from kinetic analysis that derivative 5c irreversible enzyme inhibitor complex. It is proposed on the basis of our investigation that title compound 5c may serve as lead structure for the design of more potent acetylcholinesterase inhibitors.

  13. Inhibitory effect of leaves extracts of Ocimum basilicum and Ocimum gratissimum on two key enzymes involved in obesity and hypertension in vitro

    Directory of Open Access Journals (Sweden)

    Emmanuel Anyachukwu Irondi

    2016-12-01

    Full Text Available Aim: To evaluate the phenolics composition and inhibitory effect of the leaves extracts of Ocimum basilicum (O. basilicum and Ocimum gratissimum (O. gratissimum on two key enzymes [pancreatic lipase (PL and angiotensin 1-converting enzyme (ACE] involved in obesity and hypertension in vitro. Methods: The phenolics (flavonoids and phenolic acids were quantified using high performance liquid chromatrography coupled with diode array detection (HPLC-DAD. PL and ACE inhibitory effects; and DPPH* and ABTS*+ scavenging activities of the extracts were tested using Spectrophotometric methods. Results: O. basilicum had the following major phenolics: rutin, quercetin and quercitrin (flavonoids; caffeic, chlorogenic and gallic acids (phenolic acids; while O. gratissimum had the following major phenolics: rutin, quercitrin and luteolin (flavonoids; ellagic and chlorogenic acids (phenolic acids. Extracts of both plants inhibited PL and ACE; and scavenged DPPH* in a dose-dependent manner. O. gratissimum extract was more potent in inhibiting PL (IC50: 20.69 μg/mL and ACE (IC50: 29.44 μg/mL than O. basilicum (IC50: 52.14 μg/mL and IC50: 64.99 μg/mL, against PL and ACE, respectively. O. gratissimum also scavenged DPPH* and ABTS*+ more than O. basilicum. Conclusion: O. basilicum and O. gratissimum leaves could be used as functional foods for the management of obesity and obesity-related hypertension. However, O. gratissimum may be more effective than O. basilicum. [J Complement Med Res 2016; 5(4.000: 396-402

  14. Current concepts on selected plant secondary metabolites with promising inhibitory effects against enzymes linked to Alzheimer's disease.

    Science.gov (United States)

    Orhan, I Erdogan

    2012-01-01

    Alzheimer's disease (AD) has become one of the deadliest diseases for human beings with special incidence in elderly population. It is a progressive neurodegenerative disease and the most prevalent cause of dementia. The neuropathology of AD has not been fully elucidated yet, however, cholinergic hypothesis is the most accepted theory nowadays, resulting from the cholinergic deficit emerging in the brains of AD patients. Shortage of the neurotransmitters, acetylcholine and butyrylcholine has been demonstrated, and therefore, inhibition of the enzymes; acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) that break down acetylcholine and butyrylcholine has become a standard approach for AD treatment. However, cholinesterase inhibitors are only effective in symptomatic treatment and have no ability to impede the disease. The pathogenesis of AD is highly complex and another hypothesis is the formation of amyloid plaques containing beta-amyloid peptide, which causes neurolesions in the brains of AD patients. Beta-amyloid peptide is generated after the sequential cleavage of amyloid precursor protein, especially by the beta- and gamma-secretase in the amyloidogenic pathway. The secretases involved in the processing of amyloid precursor protein are of particular interest and, consequently, the inhibition of secretase enzyme family of protease type has become another desired treatment strategy for AD. On the other hand, medicinal plants are attractive sources for drug research and development as they produce chemically-varying molecules with preferred biological activities. The aim of this article is to review the available data on selected inhibitors from plant secondary metabolites with emphasis on cholinesterase, prolyl endopeptidase, and secretase enzyme families as being the current treatments of AD.

  15. Preparation and evaluation of a coumarin library towards the inhibitory activity of the enzyme gGAPDH from Trypanosoma cruzi

    Energy Technology Data Exchange (ETDEWEB)

    Alvim Junior, Joel; Dias, Ricardo L.A.; Correa, Arlene G. [Universidade Federal de Sao Carlos, SP (Brazil). Dept. de Quimica]. E-mail: agcorrea@power.ufscar.br; Castilho, Marcelo S.; Oliva, Glaucius [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Fisica

    2005-07-15

    Chagas' disease, caused by Trypanosoma cruzi, is endemic in 15 countries in Latin America. In this work a library of 38 coumarins was prepared in solution phase and evaluated against T. cruzi glycolytic enzyme glyceraldehyde-3-phosphate-dehydrogenase (gGAPDH). The synthetic route was based on the Knoevenagel condensation of different 2-hydroxybenzaldehydes with Meldrum's acid or diethyl malonate, followed by O-alkylation and/or transesterification reactions. Among the prepared coumarins, the best values obtained to inhibit 50% of the enzymatic activity range from 80 to 130 {mu}M. (author)

  16. Preparation and evaluation of a coumarin library towards the inhibitory activity of the enzyme gGAPDH from Trypanosoma cruzi

    International Nuclear Information System (INIS)

    Alvim Junior, Joel; Dias, Ricardo L.A.; Correa, Arlene G.; Castilho, Marcelo S.; Oliva, Glaucius

    2005-01-01

    Chagas' disease, caused by Trypanosoma cruzi, is endemic in 15 countries in Latin America. In this work a library of 38 coumarins was prepared in solution phase and evaluated against T. cruzi glycolytic enzyme glyceraldehyde-3-phosphate-dehydrogenase (gGAPDH). The synthetic route was based on the Knoevenagel condensation of different 2-hydroxybenzaldehydes with Meldrum's acid or diethyl malonate, followed by O-alkylation and/or transesterification reactions. Among the prepared coumarins, the best values obtained to inhibit 50% of the enzymatic activity range from 80 to 130 μM. (author)

  17. Novel zinc(II)phthalocyanines bearing azo-containing schiff base: Determination of pKa values, absorption, emission, enzyme inhibition and photochemical properties

    Science.gov (United States)

    Kantar, Cihan; Mavi, Vildan; Baltaş, Nimet; İslamoğlu, Fatih; Şaşmaz, Selami

    2016-10-01

    Azo-containing schiff bases are well known and there are many studies about their various properties in literature. However, phthalocyanines bearing azo-containing schiff bases, their spectral, analytical and biological properties are unknown. Therefore, new zinc (II) phthalocyanines bearing azo-containing schiff base were synthesized and investigated to determine pKa values, absorption, emission, enzyme inhibition and photochemical properties. Emission spectra were reported and large Stokes shift values were determined for all compounds, indicating that all molecules exhibit excited state intramolecular proton transfer. These phthalocyanines were the first examples of phthalocyanine showing excited state intramolecular proton transfer. Singlet oxygen quantum yields of zinc (II) phthalocyanines were determined. pKa values and indicator properties of all compounds were investigated by potentiometry. All compounds were assayed for inhibitory activity against bovine milk xanthine oxidase and acetylcholinesterase enzyme in vitro. Compound 2 showed the high inhibitory effect against xanthine oxidase (IC50 = 0.24 ± 0.01 μM). However, phthalocyanine compounds did not show enzyme inhibitor behavior.

  18. Biocatalysis with thermostable enzymes: structure and properties of a thermophilic 'ene'-reductase related to old yellow enzyme.

    Science.gov (United States)

    Adalbjörnsson, Björn V; Toogood, Helen S; Fryszkowska, Anna; Pudney, Christopher R; Jowitt, Thomas A; Leys, David; Scrutton, Nigel S

    2010-01-25

    We report the crystal structure of a thermophilic "ene" reductase (TOYE) isolated from Thermoanaerobacter pseudethanolicus E39. The crystal structure reveals a tetrameric enzyme and an active site that is relatively large compared to most other structurally determined and related Old Yellow Enzymes. The enzyme adopts higher order oligomeric states (octamers and dodecamers) in solution, as revealed by sedimentation velocity and multiangle laser light scattering. Bead modelling indicates that the solution structure is consistent with the basic tetrameric structure observed in crystallographic studies and electron microscopy. TOYE is stable at high temperatures (T(m)>70 degrees C) and shows increased resistance to denaturation in water-miscible organic solvents compared to the mesophilic Old Yellow Enzyme family member, pentaerythritol tetranitrate reductase. TOYE has typical ene-reductase properties of the Old Yellow Enzyme family. There is currently major interest in using Old Yellow Enzyme family members in the preparative biocatalysis of a number of activated alkenes. The increased stability of TOYE in organic solvents is advantageous for biotransformations in which water-miscible organic solvents and biphasic reaction conditions are required to both deliver novel substrates and minimize product racemisation.

  19. Angiotensin-I converting enzyme inhibitory peptides from antihypertensive skate (Okamejei kenojei) skin gelatin hydrolysate in spontaneously hypertensive rats.

    Science.gov (United States)

    Ngo, Dai-Hung; Kang, Kyong-Hwa; Ryu, BoMi; Vo, Thanh-Sang; Jung, Won-Kyo; Byun, Hee-Guk; Kim, Se-Kwon

    2015-05-01

    The aim of this study was to investigate antihypertensive effect of bioactive peptides from skate (Okamejei kenojei) skin gelatin. The Alcalase/protease gelatin hydrolysate below 1 kDa (SAP) exhibited the highest angiotensin-I converting enzyme (ACE) inhibition compared to other hydrolysates. SAP can decrease systolic blood pressure significantly in spontaneously hypertensive rats. SAP inhibited vasoconstriction via PPAR-γ expression, activation and phosphorylation of eNOS in lungs. Moreover, the expression levels of endothelin-1, RhoA, α-smooth muscle actin, cleaved caspase 3 and MAPK were decreased by SAP in lungs. Vascularity, muscularization and cellular proliferation in lungs were detected by immunohistochemical staining. Finally, two purified peptides (LGPLGHQ, 720Da and MVGSAPGVL, 829Da) showed potent ACE inhibition with IC50 values of 4.22 and 3.09 μM, respectively. These results indicate that bioactive peptides isolated from skate skin gelatin may serve as candidates against hypertension and could be used as functional food ingredients. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Two Ganoderma species: profiling of phenolic compounds by HPLC-DAD, antioxidant, antimicrobial and inhibitory activities on key enzymes linked to diabetes mellitus, Alzheimer's disease and skin disorders.

    Science.gov (United States)

    Zengin, Gokhan; Sarikurkcu, Cengiz; Gunes, Erdogan; Uysal, Ahmet; Ceylan, Ramazan; Uysal, Sengul; Gungor, Halil; Aktumsek, Abdurrahman

    2015-08-01

    This work reports the antioxidant, antimicrobial, and inhibitory effects of methanol and water extracts from Ganoderma applanatum (GAM: methanol extract and GAW: water extract) and G. resinaceum (GRM: methanol extract and GRW: water extract) against cholinesterase, tyrosinase, α-amylase and α-glucosidase. The total phenolics, flavonoids contents, and HPLC profile of phenolic components present in the extracts, were also determined. Antioxidant activities were investigated by using different assays, including DPPH, ABTS, FRAP, CUPRAC, phosphomolybdenum and metal chelating assays. Antimicrobial activity of the tested Ganoderma extracts was also studied by the broth microdilution method. Generally, the highest antioxidant (59.24 mg TEs per g extract for DPPH, 41.32 mg TEs per g extract for ABTS, 41.35 mg TEs per g extract for CUPRAC, 49.68 mg TEs per g extract for FRAP, 130.57 mg AAEs per g extract for phosphomolybdenum and 26.92 mg EDTAEs per g extract) and enzyme inhibitory effects (1.47 mg GALAEs per g extract for AChE, 1.51 mg GALAEs per g extract for BChE, 13.40 mg KAEs per g extract for tyrosinase, 1.13 mmol ACEs per g extract for α-amylase and 2.20 mmol ACEs per g extract for α-glucosidase) were observed in GRM, which had the highest concentrations of phenolics (37.32 mg GAEs g(-1) extract). Again, Ganoderma extracts possess weak antibacterial and antifungal activities. Apigenin and protocatechuic acid were determined as the main components in GRM (1761 μg per g extract) and GAM (165 μg per g extract), respectively. The results suggest that the Ganoderma species may be considered as a candidate for preparing new food supplements and can represent a good model for the development of new drug formulations.

  1. Inhibitory potentials of phenolic-rich extracts from Bridelia ferruginea on two key carbohydrate-metabolizing enzymes and Fe2+-induced pancreatic oxidative stress.

    Science.gov (United States)

    Afolabi, Olakunle Bamikole; Oloyede, Omotade Ibidun; Agunbiade, Shadrack Oludare

    2018-05-01

    The current study was designed to evaluate the various antioxidant potentials and inhibitory effects of phenolic-rich leaf extracts of Bridelia ferruginea (BF) on the in vitro activities of some key enzymes involved in the metabolism of carbohydrates. In this study, BF leaf free and bound phenolic-rich extracts were used. We quantified total phenolic and flavonoid contents, and evaluated several antioxidant activities using assays for ferric reducing antioxidant power, total antioxidant activity (phosphomolybdenum reducing ability), 1,1-diphenyl-2-picrylhydrazyl and thiobarbituric acid reactive species. Also, extracts were tested for their ability to inhibit α-amylase and α-glucosidase activity. The total phenolic and total flavonoid contents in the free phenolic extract of BF were significantly greater than in the bound phenolic extract. Also, all the antioxidant activities considered were significantly greater in the free phenolic extract than in the bound phenolic extract. In the same vein, the free phenolic-rich extract had a significantly higher percentage inhibition against α-glucosidase activity (IC 50  = 28.5 µg/mL) than the bound phenolic extract (IC 50  = 340.0 µg/mL). On the contrary, the free phenolic extract (IC 50  = 210.0 µg/mL) had significantly lower inhibition against α-amylase than the bound phenolic-rich extract (IC 50  = 190.0 µg/mL). The phenolic-rich extracts of BF leaves showed antioxidant potentials and inhibited two key carbohydrate-metabolizing enzymes in vitro. Copyright © 2018 Shanghai Changhai Hospital. Published by Elsevier B.V. All rights reserved.

  2. Inhibitory Effects of Aschantin on Cytochrome P450 and Uridine 5′-diphospho-glucuronosyltransferase Enzyme Activities in Human Liver Microsomes

    Directory of Open Access Journals (Sweden)

    Soon-Sang Kwon

    2016-04-01

    Full Text Available Aschantin is a bioactive neolignan found in Magnolia flos with antiplasmodial, Ca2+-antagonistic, platelet activating factor-antagonistic, and chemopreventive activities. We investigated its inhibitory effects on the activities of eight major human cytochrome P450 (CYP and uridine 5′-diphospho-glucuronosyltransferase (UGT enzymes of human liver microsomes to determine if mechanistic aschantin–enzyme interactions were evident. Aschantin potently inhibited CYP2C8-mediated amodiaquine N-de-ethylation, CYP2C9-mediated diclofenac 4′-hydroxylation, CYP2C19-mediated [S]-mephenytoin 4′-hydroxylation, and CYP3A4-mediated midazolam 1′-hydroxylation, with Ki values of 10.2, 3.7, 5.8, and 12.6 µM, respectively. Aschantin at 100 µM negligibly inhibited CYP1A2-mediated phenacetin O-de-ethylation, CYP2A6-mediated coumarin 7-hydroxylation, CYP2B6-mediated bupropion hydroxylation, and CYP2D6-mediated bufuralol 1′-hydroxylation. At 200 µM, it weakly inhibited UGT1A1-catalyzed SN-38 glucuronidation, UGT1A6-catalyzed N-acetylserotonin glucuronidation, and UGT1A9-catalyzed mycophenolic acid glucuronidation, with IC50 values of 131.7, 144.1, and 71.0 µM, respectively, but did not show inhibition against UGT1A3, UGT1A4, or UGT2B7 up to 200 µM. These in vitro results indicate that aschantin should be examined in terms of potential interactions with pharmacokinetic drugs in vivo. It exhibited potent mechanism-based inhibition of CYP2C8, CYP2C9, CYP2C19, and CYP3A4.

  3. Purification and properties of a new dehalogenase enzyme from ...

    African Journals Online (AJOL)

    Halogenated compounds are widely used in agriculture and industries and have been associated with environmental pollution. Degradation of 3-chloropropionate (3CP) by microorganism has been established and this enzyme could only remove halogen atom at the â- position of 3-carbon alkanoic acids. Pseudomonas sp ...

  4. Green asparagus (Asparagus officinalis) prevented hypertension by an inhibitory effect on angiotensin-converting enzyme activity in the kidney of spontaneously hypertensive rats.

    Science.gov (United States)

    Sanae, Matsuda; Yasuo, Aoyagi

    2013-06-12

    Green asparagus (Asparagus officinalis) is known to be rich in functional components. In the present study, spontaneously hypertensive rats (SHR) were used to clarify whether green asparagus prevents hypertension by inhibition of angiotensin-converting enzyme (ACE) activity. Six-week-old male SHR were fed a diet with (AD group) or without (ND group) 5% asparagus for 10 weeks. Systolic blood pressure (SBP) (AD: 159 ± 4.8 mmHg, ND: 192 ± 14.7 mmHg), urinary protein excretion/creatinine excretion, and ACE activity in the kidney were significantly lower in the AD group compared with the ND group. Creatinine clearance was significantly higher in the AD group compared with the ND group. In addition, ACE inhibitory activity was observed in a boiling water extract of asparagus. The ACE inhibitor purified and isolated from asparagus was identified as 2″-hydroxynicotianamine. In conclusion, 2″-hydroxynicotianamine in asparagus may be one of the factors inhibiting ACE activity in the kidney, thus preventing hypertension and preserving renal function.

  5. Inhibitory Activities of Zygophyllum album: A Natural Weight-Lowering Plant on Key Enzymes in High-Fat Diet-Fed Rats

    Science.gov (United States)

    Mnafgui, Kais; Hamden, Khaled; Ben Salah, Hichem; Kchaou, Mouna; Nasri, Mbarek; Slama, Sadok; Derbali, Fatma; Allouche, Noureddine; Elfeki, Abdelfattah

    2012-01-01

    Obesity is a serious health problem that increased risk for many complications, including diabetes and cardiovascular disease. The results showed EZA, which found rich in flavonoids and phenolic compounds, exhibited an inhibitory activity on pancreatic lipase in vitro with IC50 of 91.07 μg/mL. In vivo administration of this extract to HFD-rats lowered body weight and serum leptin level; and inhibited lipase activity of obese rats by 37% leading to notable decrease of T-Ch, TGs and LDL-c levels accompanied with an increase in HDL-c concentration in serum and liver of EZA treated HFD-rats. Moreover, the findings revealed that EZA helped to protect liver tissue from the appearance of fatty cysts. Interestingly, supplementation of EZA modulated key enzyme related to hypertension such as ACE by 36% in serum of HFD animals and improve some of serum electrolytes such as Na+, K+, Cl−, Ca2+ and Mg2+. Moreover, EZA significantly protected the liver-kidney function by reverted back near to normal the values of the liver-kidney dysfunction indices AST&ALT, ALP, CPK and GGT activities, decreased T-Bili, creat, urea and uric acid rates. In conclusion, these results showed a strong antihypelipidemic effect of EZA which can delay the occurrence of dislipidemia and hypertension. PMID:23258993

  6. Effect of oxidative enzymes on bulk rheological properties of wheat flour doughs

    NARCIS (Netherlands)

    Dunnewind, B.; Vliet, T. van; Orsel, R.

    2002-01-01

    The use of enzymes such as peroxidases or glucose oxidase instead of chemical oxidants is a very interesting option for improving breadmaking performance of doughs. In this study the effect of such enzymes on bulk rheological properties of dough was quantified and their influence on the polymer

  7. Effect of Oxidative Enzymes on Bulk Rheological Properties of Wheat Flour Doughs

    NARCIS (Netherlands)

    Dunnewind, B.; Vliet, van T.; Orsel, R.

    2002-01-01

    The use of enzymes such as peroxidases or glucose oxidase instead of chemical oxidants is a very interesting option for improving breadmaking performance of doughs. In this study the effect of such enzymes on bulk rheological properties of dough was quantified and their influence on the polymer

  8. Effect of enzyme and oxidative treatments on the properties of coarse wool and mohair

    CSIR Research Space (South Africa)

    Barkhuysen, FA

    2005-09-01

    Full Text Available and the current study focused on the effect of enzymes, either alone or in combination with an oxidative (chlorine) treatment, on the softness and other properties of the fibres. It was found that an enzyme treatment reduced the feltability of wool. Furthermore...

  9. Inhibitory effects of Urtica dioica L. root on electrophysiological properties of isolated rabbit atrioventricular node

    OpenAIRE

    A. Enayati; V. Khori*; M. Azadbakhat; M. Zahedi

    2017-01-01

    Background and objectives: The ideal drug for treatment of a wide range of supraventricular arrhythmia hasn't yet been developed. Previous studies have shown antihypertensive and negative inotropic effects of the Urtica dioica L. (nettle). Therefore, the aim of present study is to determine the rate dependent inhibitory effects of ethanol extract of nettle root and investigate the role of adrenoceptors in the anti-arrhythmic mechanism of nettle on the isolated rabbit atrio-ventricular node. M...

  10. Inhibitory Properties of Lactic Acid Bacteria against Moulds Associated with Spoilage of Bakery Products

    OpenAIRE

    I. A. Adesina; A. O. Ojokoh; D. J. Arotupin

    2017-01-01

    Aim: To evaluate the potentiality of LAB strains isolated from different fermented products to inhibit moulds associated with spoilage of bakery products. Methodology: Lactic acid bacterial (LAB) strains obtained from fermented products (“burukutu”, “pito”, yoghurt, and “iru”) were screened for antifungal activity against moulds (Aspergillus flavus, Aspergillus fumigatus, Aspergillus repens and Penicillium sp.) isolated from spoilt bakery products. Inhibitory activities of the lactic acid...

  11. Statistical properties of multistep enzyme-mediated reactions

    OpenAIRE

    de Ronde, Wiet H.; Daniels, Bryan C.; Mugler, Andrew; Sinitsyn, Nikolai A.; Nemenman, Ilya

    2008-01-01

    Enzyme-mediated reactions may proceed through multiple intermediate conformational states before creating a final product molecule, and one often wishes to identify such intermediate structures from observations of the product creation. In this paper, we address this problem by solving the chemical master equations for various enzymatic reactions. We devise a perturbation theory analogous to that used in quantum mechanics that allows us to determine the first () and the second (variance) cumu...

  12. Starch Hydrolysis, Polyphenol Contents, and In Vitro Alpha Amylase Inhibitory Properties of Some Nigerian Foods As Affected by Cooking

    Directory of Open Access Journals (Sweden)

    Sani Saidu

    2017-12-01

    Full Text Available The effect of cooking on starch hydrolysis, polyphenol contents, and in vitro α-amylase inhibitory properties of mushrooms (two varieties Russula virescens and Auricularia auricula-judae, sweet potato (Ipomea batatas, and potato (Solanum tuberosum was investigated. The total, resistant, and digestible starch contents of the raw and cooked food samples (FS ranged from 6.4 to 64.9; 0 to 10.1; and 6.4 to 62.7 g/100 g, respectively, while their percentages of starch digestibility (DS values expressed as percentages of total starch hydrolyzed ranged from 45.99 to 100. Raw and boiled unpeeled potato, raw and boiled peeled potato, raw A. auricula-judae, and sweet potato showed mild to high α-amylase inhibition (over a range of concentration of 10–50 mg/mL, which was lower than that of acarbose (that had 69% inhibition of α-amylase over a range of concentration of 2–10 mg/mL, unlike raw R. virescens, boiled A. auricula-judae, and boiled sweet potatoes that activated α-amylase and boiled R. virescens that gave 0% inhibition. The FS contained flavonoids and phenols in addition. The significant negative correlation (r = −0.55; P = 0.05 between the α-amylase inhibitory properties of the raw and cooked FS versus their SD indicates that the α-amylase inhibitors in these FS also influenced the digestibility of their starches. In addition, the significant positive correlation between the α-amylase inhibitory properties of the raw and cooked FS versus their resistant starch (RS (r = 0.59; P = 0.01 contents indicates that the RS constituents of these FS contributed to their α-amylase inhibitory properties. The study showed the usefulness of boiled unpeeled potato, boiled potato peeled, and raw sweet potato as functional foods for people with type 2 diabetes.

  13. Assessment of inhibitory effects on major human cytochrome P450 enzymes by spasmolytics used in the treatment of overactive bladder syndrome.

    Science.gov (United States)

    Dahlinger, Dominik; Aslan, Sevinc; Pietsch, Markus; Frechen, Sebastian; Fuhr, Uwe

    2017-07-01

    The objective of this study was to examine the inhibitory potential of darifenacin, fesoterodine, oxybutynin, propiverine, solifenacin, tolterodine and trospium chloride on the seven major human cytochrome P450 enzymes (CYP) by using a standardized and validated seven-in-one cytochrome P450 cocktail inhibition assay. An in vitro cocktail of seven highly selective probe substrates was incubated with human liver microsomes and varying concentrations of the seven test compounds. The major metabolites of the probe substrates were simultaneously analysed using a validated liquid chromatography tandem mass spectrometry (LC-MS/MS) method. Enzyme kinetics were estimated by determining IC 50 and K i values via nonlinear regression. Obtained K i values were used for predictions of potential clinical impact of the inhibition using a static mechanistic prediction model. In this study, 49 IC 50 experiments were conducted. In six cases, IC 50 values lower than the calculated threshold for drug-drug interactions (DDIs) in the gut wall were observed. In these cases, no increase in inhibition was determined after a 30 min preincubation. Considering a typical dosing regimen and applying the obtained K i values of 0.72 µM (darifenacin, 15 mg daily) and 7.2 µM [propiverine, 30 mg daily, immediate release (IR)] for the inhibition of CYP2D6 yielded a predicted 1.9-fold and 1.4-fold increase in the area under the curve (AUC) of debrisoquine (CYP2D6 substrate), respectively. Due to the inhibition of the particular intestinal CYP3A4, the obtained K i values of 14 µM of propiverine (30 mg daily, IR) resulted in a predicted doubling of the AUC for midazolam (CYP3A4 substrate). In vitro / in vivo extrapolation based on pharmacokinetic data and the conducted screening experiments yielded similar effects of darifenacin on CYP2D6 and propiverine on CYP3A4 as obtained in separately conducted in vivo DDI studies. As a novel finding, propiverine was identified to potentially inhibit CYP2D6 at

  14. Effect of enzyme treatment on pea starch physicomechanical properties of biofilms

    OpenAIRE

    A. Sh. Zakirova; T. N. Manahova; A. V. Kanarskiy; Z. A. Kanarskaya

    2013-01-01

    The regularities of change in physical and mechanical properties of biofilms based on pea starch treated with pullulanase enzyme preparation were obtained. The possibility of formation of linear pea starch amylopectin polymers, which contribute to improvement of the mechanical and rheological properties of biofilms was identified.

  15. Effect of enzyme treatment on pea starch physicomechanical properties of biofilms

    Directory of Open Access Journals (Sweden)

    A. Sh. Zakirova

    2013-01-01

    Full Text Available The regularities of change in physical and mechanical properties of biofilms based on pea starch treated with pullulanase enzyme preparation were obtained. The possibility of formation of linear pea starch amylopectin polymers, which contribute to improvement of the mechanical and rheological properties of biofilms was identified.

  16. Thermophysical properties of enzyme clarified Lime (Citrus aurantifolia L) juice at different moisture contents.

    Science.gov (United States)

    Manjunatha, S S; Raju, P S; Bawa, A S

    2014-11-01

    Thermophysical properties of enzyme clarified lime (Citrus aurantifolia L.) juice were evaluated at different moisture contents ranging from 30.37 % to 89.30 % (wet basis) corresponding to a water activity range of 0.835 to 0.979. The thermophysical properties evaluated were density, Newtonian viscosity, thermal conductivity, specific heat and thermal diffusivity. The investigation showed that density and Newtonian viscosity of enzyme clarified lime juice decreased significantly (p lime juice with moisture content/water activity employing regression analysis by the method of least square approximation. Results indicated the existence of strong correlation between thermophysical properties and moisture content/water activity of enzyme clarified lime juice, a significant (p < 0.0001) negative correlation between physical and thermal properties was observed.

  17. Reconstructed Ancestral Enzymes Impose a Fitness Cost upon Modern Bacteria Despite Exhibiting Favourable Biochemical Properties.

    Science.gov (United States)

    Hobbs, Joanne K; Prentice, Erica J; Groussin, Mathieu; Arcus, Vickery L

    2015-10-01

    Ancestral sequence reconstruction has been widely used to study historical enzyme evolution, both from biochemical and cellular perspectives. Two properties of reconstructed ancestral proteins/enzymes are commonly reported--high thermostability and high catalytic activity--compared with their contemporaries. Increased protein stability is associated with lower aggregation rates, higher soluble protein abundance and a greater capacity to evolve, and therefore, these proteins could be considered "superior" to their contemporary counterparts. In this study, we investigate the relationship between the favourable in vitro biochemical properties of reconstructed ancestral enzymes and the organismal fitness they confer in vivo. We have previously reconstructed several ancestors of the enzyme LeuB, which is essential for leucine biosynthesis. Our initial fitness experiments revealed that overexpression of ANC4, a reconstructed LeuB that exhibits high stability and activity, was only able to partially rescue the growth of a ΔleuB strain, and that a strain complemented with this enzyme was outcompeted by strains carrying one of its descendants. When we expanded our study to include five reconstructed LeuBs and one contemporary, we found that neither in vitro protein stability nor the catalytic rate was correlated with fitness. Instead, fitness showed a strong, negative correlation with estimated evolutionary age (based on phylogenetic relationships). Our findings suggest that, for reconstructed ancestral enzymes, superior in vitro properties do not translate into organismal fitness in vivo. The molecular basis of the relationship between fitness and the inferred age of ancestral LeuB enzymes is unknown, but may be related to the reconstruction process. We also hypothesise that the ancestral enzymes may be incompatible with the other, contemporary enzymes of the metabolic network.

  18. Adhesive Properties and Acid-Forming Activity of Lactobacilli and Streptococci Under Inhibitory Substances, Such as Nitrates.

    Science.gov (United States)

    Hakobyan, L; Harutyunyan, K; Harutyunyan, N; Melik-Andreasyan, G; Trchounian, A

    2016-06-01

    One of the main requirements for probiotics is their ability to survive during passage through gastrointestinal tract and to maintain their activity at different adverse conditions. The aim of the study was to look for the strains of lactobacilli and streptococci with high adhesive properties even affected by inhibitory substances, such as nitrates (NO3 (-)). To study the adhesion properties hemagglutination reaction of bacterial cells with red blood cells of different animals and humans was used. The acid formation ability of bacteria was determined by the method of titration after 7 days of incubation in the sterile milk. These properties were investigated at different concentrations of NO3 (-). The high concentration (mostly ≥2.0 %) NO3 (-) inhibited the growth of both lactobacilli and streptococci, but compared with streptococcal cultures lactobacilli, especially Lactobacillus acidophilus Ep 317/402, have shown more stability and higher adhesive properties. In addition, the concentrations of NO3 (-) of 0.5-2.0 % decreased the acid-forming activity of the strains, but even under these conditions they coagulated milk and, in comparison to control, formed low acidity in milk. Thus, the L. acidophilus Ep 317/402 with high adhesive properties has demonstrated a higher activity of NO3 (-) transformation.

  19. Alpha-glucosidase inhibitory and antiplasmodial properties of terpenoids from the leaves of Buddleja saligna Willd.

    Science.gov (United States)

    Chukwujekwu, Jude C; Rengasamy, Kannan R R; de Kock, Carmen A; Smith, Peter J; Slavětínská, Lenka Poštová; van Staden, Johannes

    2016-01-01

    In our continuing search for biologically active natural product(s) of plant origin, Buddleja saligna, a South African medicinal plant, was screened in line with its traditional use for antidiabetic (yeast alpha glucosidase inhibitory) and antiplasmodial (against a chloroquine sensitive strain of Plasmodium falciparum (NF54)) activities. The hexane fraction showed the most promising activity with regards to its antidiabetic (IC(50) = 260 ± 0.112 µg/ml) and antiplasmodial (IC(50) = 8.5 ± 1.6 µg/ml) activities. Using activity guided fractionation three known terpenoids (betulonic acid, betulone and spinasterol) were isolated from this species for the first time. The compounds displayed varying levels of biological activities (antidiabetic: 27.31 µg/ml ≥ IC(50) ≥ 5.6 µg/ml; antiplasmodial: 14 µg/ml ≥ IC(50) ≥ 2 µg/ml) with very minimal toxicity.

  20. Inhibitory activity of phenolic-rich pistachio green hull extract-enriched pasta on key type 2 diabetes relevant enzymes and glycemic index.

    Science.gov (United States)

    Lalegani, Sajjad; Ahmadi Gavlighi, Hassan; Azizi, Mohammad Hossein; Amini Sarteshnizi, Roghayeh

    2018-03-01

    Phenolic compounds as agro-industrial by-products have been associated with health benefits since they exhibit high antioxidant activity and anti-diabetic properties. In this study, polyphenol-rich extract from pistachio green hull (PGH) was evaluated for antioxidant activity and its ability to inhibit α-amylase and α-glucosidase activity in vitro. The effect of PGH extract powder on in vitro starch digestibility was also evaluated. The results showed that PGH had stronger antioxidant activity than Trolox. The inhibitory effect of PGH extract against α-amylase from porcine pancreas was dose dependent and the IC 50 value was ~174μgGAE/mL. The crude PGH extract was eight times more potent on baker yeast α-glucosidase activity (IC 50 ~6μgGAE/mL) when compared to acarbose, whereas the IC 50 value of PGH extract against rat intestinal maltase activity obtained ~2.6mgGAE/mL. The non-tannin fraction of PGH extract was more effective against α-glucosidase than tannin fraction whereas the α-amylase inhibitor was concentrated in the tannin fraction. In vitro starch digestibility and glycemic index (GI) of pasta sample supplemented with PGH extract powder (1.5%) was significantly lower than the control pasta. The IC 50 value of PGH extract obtained from cooked pasta against α-amylase and α-glucosidase was increased. These results have important implications for the processing of PGH for food industry application and therefore could comply with glucose control diets. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. ENZYME ACTIVITIES OF PADDY SOILS AND RELATIONSHIPS WITH THE SOIL PROPERTIES

    Directory of Open Access Journals (Sweden)

    Rıdvan KIZILKAYA

    1998-03-01

    Full Text Available This study was carried out to determine the effect of soil properties on enzyme activities of paddy soils, the sample of which were taken from Üçpınar, Harız, Doğancı, Kaygusuz, Emenli, Sarıköy and Gelemenağarı villages where rice cultivation is an intensive agricultural system. In this study, soil properties having effects on urease, phosphatase, ß-glucosidase and catalase enzyme activities were setforth. Urease enzyme activities of soil samples varied from 24.12 to 39.03 mg N 100 g dry soil -1 . Significant correlations were determined between urease enzyme activities and organic matter (r = 0.89**, extractable Mn (r = 0.74**, exchangable K (r = 0.73** and total P content of soil (r = 0.81*. Acid phosphatase enzyme activity varied between 3.00-17.44 mg phenol 100 g dry soil -1 , alkaline phosphatase enzyme activity between 12.00-25.53 mg phenol 100 g dry soil-1 . Exchangable Mg (r = 0.71* and extractable Cu (r = 0.74* were found to have positive effect on acid phosphatase enzyme activity and pH (r = 0.73*, exchangable Ca (r = 0.74*, exchangable Mg (r = 0.71*, exchangable total basic cations (r = 0.79* and extractable Cu (r = 0.70* had positive effects on alkaline phosphatase enzyme activity, whereas total P (r = - 0.84** affected the activity negatively. ß-glucosidase enzyme activity was measured to vary between 1.12-3.64 mg salingen 100 g dry soil -1 . It was also observed that extractable Zn content of soil samples (r = - 0.97** had negative effect on ß-glucosidase activity, wheras total exchangable acidic cations (r = 0.70* affected the activity positively. Catalase enzyme activities of soils changed between 5.25 - 9.00 mg O2 5 g dry soil -1 . Significant correlations were found between catalase activities and fraction of soils and extractable Fe content. Positive correlations, however, were determined between catalase activities and clay fraction (r = 0.82* and salt content (r = 0.83** of samples.

  2. Angiotensin I-converting enzyme inhibitory activity and antioxidant capacity of bioactive peptides derived from enzymatic hydrolysis of buffalo milk proteins

    DEFF Research Database (Denmark)

    Abdel-Hamid, Mahmoud; Otte, Jeanette; De Gobba, Cristian

    2017-01-01

    was hydrolysed using papain, pepsin or trypsin. The papain hydrolysate showed the highest ACE-inhibitory activity and radical scavenging capacity and was fractionated by size exclusion chromatography (SEC) and characterized by LC-MS analysis. A SEC-fraction with intermediate peptide size showed very high ACE...

  3. A general overview of support materials for enzyme immobilization: Characteristics, properties, practical utility

    DEFF Research Database (Denmark)

    Zdarta, Jakub; Meyer, Anne S.; Jesionowski, Teofil

    2018-01-01

    on the properties of the produced catalytic system. A large variety of inorganic and organic as well as hybrid and composite materials may be used as stable and efficient supports for biocatalysts. This review provides a general overview of the characteristics and properties of the materials applied for enzyme...... immobilization. For the purposes of this literature study, support materials are divided into two main groups, called Classic and New materials. The review will be useful in selection of appropriate support materials with tailored properties for the production of highly effective biocatalytic systems for use...

  4. Cytotoxicity and inhibitory properties against topoisomerase II of doxorubicin and its formamidine derivatives.

    Science.gov (United States)

    Kik, Krzysztof; Studzian, Kazimierz; Wasowska-Łukawska, Małgorzata; Oszczapowicz, Irena; Szmigiero, Leszek

    2009-01-01

    This work was undertaken to compare cytotoxicity, DNA damaging properties and effect on DNA cleavage by topoisomerase II of the anthracycline drug doxorubicin (DOX) and its two derivatives with a formamidino group containing a cyclic amine moiety such as morpholine (DOXM) or hexamethyleneimine (DOXH). The tetrazolium dye colorimetric assay was used to determine the cytotoxic activity of anthracyclines toward L1210 leukemia cells. DNA damage was measured by alkaline elution technique. The effect of anthracyclines on DNA cleavage was studied in a cell-free system containing supercoiled pBR322 DNA and purified human topoisomerase II. The cytotoxicity data and the results of studies on the mechanism of DNA break formation by anthracyclines at the cellular level and in the cell-free system showed that the presence of the formamidino group in the doxorubicin molecule reduced its ability to stimulate DNA cleavage by DNA topoisomerase II. DNA topoisomerase II is not a primary cellular target for DOXM or DOXH. An advantageous feature of formamidinoanthracyclines is their mechanism of cytotoxic action which is not related to the inhibition of DNA topoisomerase II. Therefore this class of anthracyclines seems to be a good source for selection of an anticancer drug directed toward cancer cells with the developed multidrug resistance attributed to the presence of altered DNA topoisomerase II.

  5. Vasoactive and radioprotective properties of isothiourea derivatives having NOS-inhibitory activity

    Energy Technology Data Exchange (ETDEWEB)

    Filimonova, Marina V.; Shevchenko, Ludmila I.; Ulyanenko, Stepan E.; Makarchuk, Victorya M.; Kuznetsova, Mary N.; Shevchuk, Aza S.; Lushnikova, Galina A.; Chesnakova, Ekaterina A. [Medical Radiological Research Center Health Ministry of Russia, 4, Korolev street, Obninsk, 249036, Kaluga region (Russian Federation)

    2014-07-01

    We studied vasoactive and radioprotective properties of new original N-acyl, S-alkyl isothiourea derivatives which are potent inhibitors of nitric oxide synthases (preferably eNOS and iNOS). These compounds have a moderate toxicity (LD50 - 400-550 mg/kg), and are stable in aqueous solutions. In hemodynamic studies, these compounds exhibited high vasotropic activity. The use of these compounds in doses of 5-15 mg/kg (0,01-0,03 LD{sub 50}) in the experimental animals in a state of the severe hemorrhagic or endo-toxic shock causes a potent vasopressor effect, accompanied by a significant and continuous rise in blood pressure. The increasing of vascular tone developed over 2-5 min after injection and persisted for at least 60-90 minutes, excelling at least 3-5 times the duration of α1-adreno-mimetic vasopressor action. The rapid increase in vascular tone under the influence of these compounds in normo-tonic animals caused protective baroreflex to prevent high blood pressure. At doses of 10-15 mg/kg the reflex reaction was mild, but at higher doses (30-40 mg/kg) the reaction was fierce and prolonged, and was accompanied by severe bradycardia, decreasing of the cardiac output and a significant weakening of the peripheral blood flow. In all cases, the hemodynamic response was reflexive and easily eliminated by atropine. The ability of these compounds to induce circulatory hypoxia was the basis for the study of their radioprotective properties. The study of radioprotective effect on the survival of animals exposed to lethal doses of γ-radiation (10 Gy) and on the survival of hematopoietic clonogenic cells showed that these compounds in doses of 80-150 mg/kg (0,2-0,3 LD50) have considerable radioprotective action, which is comparable with the protective effect of the maximum tolerated dose of cystamine. The factor of change in dose for γ-radiation, estimated by the LD{sub 50}, was 1,42-1,58. We also investigated the ability of the test compounds, due to their hypoxic

  6. The Evaluation of Dipeptidyl Peptidase (DPP)-IV, α-Glucosidase and Angiotensin Converting Enzyme (ACE) Inhibitory Activities of Whey Proteins Hydrolyzed with Serine Protease Isolated from Asian Pumpkin (Cucurbita ficifolia).

    Science.gov (United States)

    Konrad, Babij; Anna, Dąbrowska; Marek, Szołtysik; Marta, Pokora; Aleksandra, Zambrowicz; Józefa, Chrzanowska

    2014-01-01

    In the present study, whey protein concentrate (WPC-80) and β-lactoglobulin were hydrolyzed with a noncommercial serine protease isolated from Asian pumpkin ( Cucurbita ficifolia ). Hydrolysates were further fractionated by ultrafiltration using membranes with cut-offs equal 3 and 10 kDa. Peptide fractions of molecular weight lower than 3 and 3-10 kDa were further subjected to the RP-HPLC. Separated preparations were investigated for their potential as the natural inhibitors of dipeptidyl peptidase (DPP-IV), α-glucosidase and angiotensin converting enzyme (ACE). WPC-80 hydrolysate showed higher inhibitory activities against the three tested enzymes than β-lactoglobulin hydrolysate. Especially high biological activities were exhibited by peptide fractions of molecular weight lower than 3 kDa, with ACE IC50 food ingredients in the diet of patients with type 2 diabetes.

  7. A monomeric variant of insulin degrading enzyme (IDE loses its regulatory properties.

    Directory of Open Access Journals (Sweden)

    Eun Suk Song

    2010-03-01

    Full Text Available Insulin degrading enzyme (IDE is a key enzyme in the metabolism of both insulin and amyloid beta peptides. IDE is unique in that it is subject to allosteric activation which is hypothesized to occur through an oligomeric structure.IDE is known to exist as an equilibrium mixture of monomers, dimers, and higher oligomers, with the dimer being the predominant form. Based on the crystal structure of IDE we deleted the putative dimer interface in the C-terminal region, which resulted in a monomeric variant. Monomeric IDE retained enzymatic activity, however instead of the allosteric behavior seen with wild type enzyme it displayed Michaelis-Menten kinetic behavior. With the substrate Abz-GGFLRKHGQ-EDDnp, monomeric IDE retained approximately 25% of the wild type activity. In contrast with the larger peptide substrates beta-endorphin and amyloid beta peptide 1-40, monomeric IDE retained only 1 to 0.25% of wild type activity. Unlike wild type IDE neither bradykinin nor dynorphin B-9 activated the monomeric variant of the enzyme. Similarly, monomeric IDE was not activated by polyphosphates under conditions in which the activity of wild type enzyme was increased more than 50 fold.These findings serve to establish the dimer interface in IDE and demonstrate the requirement for an oligomeric form of the enzyme for its regulatory properties. The data support a mechanism where the binding of activators to oligomeric IDE induces a conformational change that cannot occur in the monomeric variant. Since a conformational change from a closed to a more open structure is likely the rate-determining step in the IDE reaction, the subunit induced conformational change likely shifts the structure of the oligomeric enzyme to a more open conformation.

  8. Binding of Dumbbell Oligonucleotides to MoMuLV Reverse Transcriptase: Inhibitory Properties of RNase H Activity

    Directory of Open Access Journals (Sweden)

    Ajay Kumar

    2010-01-01

    Full Text Available Dumbbell oligonucleotides with loops of various chemistry were synthesized. Incubation of dumbbell oligonucleotides containing phosphorothioate bonds or trimethylene phosphate linkages in loops with S1 nuclease did not result in significant cleavage under conditions which led to the degradation of dumbbell oligonucleotide containing phophodiester bonds in the loops. The binding of reverse transcriptase of Moloney Murine Leukemia Virus (MoMuLV was evaluated with all the five oligonucleotides. The protein binds to all the dumbbell oligonucleotides with similar affinity. The dissociation constants evaluated using PAGE band mobility shift assays were of the order of 10-7. The inhibitory properties of the retroviral RNase H activity was evaluated using 3H –UTP-labeled RNA:RNA-DNA hybrid. It was found that the best dumbbell oligonucleotide, inhibitor contained phosphorothioate residues in both the loops. Our value studies demonstrated that this particularly designed oligonucleotide displays an IC50 of 18 nM in its inhibition on the reverse transcriptase RNase H activity, a magnitude lower than that of first nucleotide reverse transcriptase of HIV-1, tenofovir, introduced by Gilead Science in the market.

  9. Screening of Peruvian Medicinal Plants for Tyrosinase Inhibitory Properties: Identification of Tyrosinase Inhibitors in Hypericum laricifolium Juss.

    Science.gov (United States)

    Quispe, Yanymee Nimesia Guillen; Hwang, Seung Hwan; Wang, Zhiqiang; Lim, Soon Sung

    2017-03-04

    Tyrosinase inhibitors are of far-ranging importance in cosmetics, medicinal products, and food industries. Peru is a diverse country with a wide variety of plants that may contain excellent anti-tyrosinase inhibitors. In the present study, the tyrosinase inhibitory properties of 50 medicinal plant extracts from Peru were investigated using tyrosinase assay. Among plant extracts, those that showed an inhibition rate >50% were Hypericum laricifolium Juss ., Taraxacum officinale F.H.Wigg ., and Muehlenbeckia vulcanica Meisn ., with H. laricifolium Juss. showing the greatest anti-tyrosinase activity. Although H. laricifolium Juss. has been widely used as a medicinal plant by Peruvians, little is known regarding its bioactive components and effects on tyrosinase activity. For this reason, we attempted to discover tyrosinase inhibitors in H. laricifolium Juss. for the first time. The bioactive components were separated by Sephadex LH-20 chromatography and eluted with 100% methanol. Eight compounds were discovered and characterized by high-performance liquid chromatography coupled with diode array detection (HPLC-DAD): protocatechuic acid, p -hydroxybenzoic acid, chlorogenic acid, vanilic acid, caffeic acid, kaempferol 3- O -glucuronide, quercetin, and kaempferol. In addition, the concentration of these compounds required for 50% inhibition (IC 50 ) of tyrosinase activity were evaluated. Quercetin exhibited the strongest tyrosinase inhibition (IC 50 14.29 ± 0.3 μM). Therefore, the Peruvian plant H. laricifolium Juss. could be a novel source for anti-tyrosinase activity.

  10. Enhancing the functional properties of thermophilic enzymes by chemical modification and immobilization.

    Science.gov (United States)

    Cowan, Don A; Fernandez-Lafuente, Roberto

    2011-09-10

    The immobilization of proteins (mostly typically enzymes) onto solid supports is mature technology and has been used successfully to enhance biocatalytic processes in a wide range of industrial applications. However, continued developments in immobilization technology have led to more sophisticated and specialized applications of the process. A combination of targeted chemistries, for both the support and the protein, sometimes in combination with additional chemical and/or genetic engineering, has led to the development of methods for the modification of protein functional properties, for enhancing protein stability and for the recovery of specific proteins from complex mixtures. In particular, the development of effective methods for immobilizing large multi-subunit proteins with multiple covalent linkages (multi-point immobilization) has been effective in stabilizing proteins where subunit dissociation is the initial step in enzyme inactivation. In some instances, multiple benefits are achievable in a single process. Here we comprehensively review the literature pertaining to immobilization and chemical modification of different enzyme classes from thermophiles, with emphasis on the chemistries involved and their implications for modification of the enzyme functional properties. We also highlight the potential for synergies in the combined use of immobilization and other chemical modifications. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Effect of enzyme/substrate ratio on the antioxidant properties of ...

    African Journals Online (AJOL)

    The antioxidant properties of African yam bean hydrolysates (AYH) produced at different enzyme to substrate (E/S) ratios of 1: 100 and 3: 100 (W/V) using pepsin (pH 2.0, 37°C) were studied. 2, 2-Diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging activity of the hydrolysates was significantly influenced by the E\\S ratio as ...

  12. Ultrafast Screening of a Novel, Moderately Hydrophilic Angiotensin-Converting-Enzyme-Inhibitory Peptide, RYL, from Silkworm Pupa Using an Fe-Doped-Silkworm-Excrement-Derived Biocarbon: Waste Conversion by Waste.

    Science.gov (United States)

    Liu, Long; Wei, Yanan; Chang, Qing; Sun, Huaju; Chai, Kungang; Huang, Zuqiang; Zhao, Zhenxia; Zhao, Zhongxing

    2017-12-27

    A novel, moderately hydrophilic peptide (RYL) with high ACE-inhibitory activity was screened ultrafast via a concept of waste conversion using waste. This novel peptide was screened from silkworm pupa using an Fe-doped porous biocarbon (FL/Z-SE) derived from silkworm excrement. FL/Z-SE possessed magnetic properties and specific selection for peptides due to Fe's dual functions. The selected RYL, which has moderate hydrophilicity (LogP = -0.22), exhibited a comparatively high ACE-inhibitory activity (IC 50 = 3.31 ± 0.11 μM). The inhibitory kinetics and docking-simulation results show that, as a competitive ACE inhibitor, RYL formed five hydrogen bonds with the ACE residues in the S1 and S2 pockets. In this work, both the screening carbon material and the selected ACE-inhibitory peptide were derived from agricultural waste (silkworm excrement and pupa), which offers a new way of thinking about the development of advanced uses of the silkworm byproducts and wastes.

  13. Rhaponticum acaule (L) DC essential oil: chemical composition, in vitro antioxidant and enzyme inhibition properties.

    Science.gov (United States)

    Mosbah, Habib; Chahdoura, Hassiba; Kammoun, Jannet; Hlila, Malek Besbes; Louati, Hanen; Hammami, Saoussen; Flamini, Guido; Achour, Lotfi; Selmi, Boulbaba

    2018-03-05

    α-glucosidase is a therapeutic target for diabetes mellitus (DM) and α-glucosidase inhibitors play a vital role in the treatments for the disease. Furthermore, xanthine oxidase (XO) is a key enzyme that catalyzes hypoxanthine and xanthine to uric acid which at high levels can lead to hyperuricemia which is an important cause of gout. Pancreatic lipase (PL) secreted into the duodenum plays a key role in the digestion and absorption of fats. For its importance in lipid digestion, PL represents an attractive target for obesity prevention. The flowers essential oil of Rhaponticum acaule (L) DC (R. acaule) was characterized using gas chromatography-mass spectrometry (GC-MS). The antioxidant activities of R. acaule essential oil (RaEO) were also determined using 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), reducing power, phosphomolybdenum, and DNA nicking assays. The inhibitory power of RaEO against α-glucosidase, xanthine oxidase and pancreatic lipase was evaluated. Enzyme kinetic studies using Michaelis-Menten and the derived Lineweaver-Burk (LB) plots were performed to understand the possible mechanism of inhibition exercised by the components of this essential oil. The result revealed the presence of 26 compounds (97.4%). The main constituents include germacrene D (49.2%), methyl eugenol (8.3%), (E)-β-ionone (6.2%), β-caryophyllene (5.7%), (E,E)-α-farnesene (4.2%), bicyclogermacrene (4.1%) and (Z)-α-bisabolene (3.7%). The kinetic inhibition study showed that the essential oil demonstrated a strong α-glucosidase inhibiton and it was a mixed inhibitor. On the other hand, our results evidenced that this oil exhibited important xanthine oxidase inhibitory effect, behaving as a non-competitive inhibitor. The essential oil inhibited the turkey pancreatic lipase, with maximum inhibition of 80% achieved at 2 mg/mL. Furthermore, the inhibition of turkey pancreatic lipase by RaEO was an irreversible one. The results revealed that the RaEO is a new

  14. Inhibitory noise

    Directory of Open Access Journals (Sweden)

    Alain Destexhe

    2010-03-01

    Full Text Available Cortical neurons in vivo may operate in high-conductance states, in which the major part of the neuron's input conductance is due to synaptic activity, sometimes several-fold larger than the resting conductance. We examine here the contribution of inhibition in such high-conductance states. At the level of the absolute conductance values, several studies have shown that cortical neurons in vivo are characterized by strong inhibitory conductances. However, conductances are balanced and spiking activity is mostly determined by fluctuations, but not much is known about excitatory and inhibitory contributions to these fluctuations. Models and dynamic-clamp experiments show that, during high-conductance states, spikes are mainly determined by fluctuations of inhibition, or by inhibitory noise. This stands in contrast to low-conductance states, in which excitatory conductances determine spiking activity. To determine these contributions from experimental data, maximum likelihood methods can be designed and applied to intracellular recordings in vivo. Such methods indicate that action potentials are indeed mostly correlated with inhibitory fluctuations in awake animals. These results argue for a determinant role for inhibitory fluctuations in evoking spikes, and do not support feed-forward modes of processing, for which opposite patterns are predicted.

  15. Mono-N-acyl-2,6-diaminopimelic acid derivatives: Analysis by electromigration and spectroscopic methods and examination of enzyme inhibitory activity

    Czech Academy of Sciences Publication Activity Database

    Hlaváček, Jan; Vítovcová, M.; Sázelová, Petra; Pícha, Jan; Vaněk, Václav; Buděšínský, Miloš; Jiráček, Jiří; Gillner, D. M.; Holz, R. C.; Mikšík, Ivan; Kašička, Václav

    2014-01-01

    Roč. 467, Dec 15 (2014), s. 4-13 ISSN 0003-2697 R&D Projects: GA ČR(CZ) GAP206/12/0453; GA ČR(CZ) GA13-17224S; GA AV ČR IAA400550614 Institutional support: RVO:61388963 ; RVO:67985823 Keywords : 2,6-diaminopimelic acid derivatives * capillary zone electrophoresis * micellar electrokinetic chromatography * enzyme inhibition Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 2.219, year: 2014

  16. The combi-targeting concept: a novel 3,3-disubstituted nitrosourea with EGFR tyrosine kinase inhibitory properties.

    Science.gov (United States)

    Qiu, Qiyu; Dudouit, Fabienne; Matheson, Stephanie L; Brahimi, Fouad; Banerjee, Ranjita; McNamee, James P; Jean-Claude, Bertrand J

    2003-01-01

    To study the dual mechanism of action of FD137, a 3,3-disubstituted nitrosourea designed to block signaling mediated by the epidermal growth factor receptor (EGFR) on its own and to be hydrolyzed to an inhibitor of EGFR plus a DNA-damaging species. HPLC was used to determine the half-life (t(1/2)) of FD137 and to characterize its derived metabolite FD110. The dual mechanisms of DNA damaging and EGFR tyrosine kinase (TK) targeting were ascertained by the comet assay for DNA damage and by inmunodetection of phosphotyrosine in an ELISA and a whole-cell assay for EGFR-mediated signaling. The antiproliferative effects of the different drugs and their combinations were determined by the sulforhodamine B (SRB) assay. In contrast to BCNU, FD137 significantly blocked EGF-induced EGFR autophosphorylation (IC(50) 4 micro M) in the human solid tumor cell line A431. DNA damage induced by FD137 could only be observed after 24 h exposure, but the level of DNA damage remained 3.6-fold lower than that induced by BCNU. This difference was rationalized by the 160-fold greater stability of FD137 when compared with BCNU in serum-containing medium. Further, degradation of FD137 was accompanied by the slow release of FD110, an extremely potent inhibitor of EGFR TK [IC(50) (EGFR autophosphorylation) <0.3 micro M]. The complex properties of FD137 translated into a 55-fold greater antiproliferative activity than BCNU against the EGFR-overexpressing A431 cells that coexpresses the O(6)-alkylguanine transferase (AGT). Depletion of AGT in these cells by the use of O(6)-benzylguanine (O(6)-BG) enhanced their sensitivity to BCNU by 8-fold, but only by 3-fold to FD137. The results overall suggest that the superior antiproliferative activity of FD137 when compared with BCNU may be associated with its ability to behave as a combination of many species with different mechanisms of action. However, the enhancement of its potency by O(6)-BG suggests that its antiproliferative effect was at least

  17. Antioxidant and Inhibitory Effects of Saponin Extracts from Dianthus basuticus Burtt Davy on Key Enzymes Implicated in Type 2 Diabetes In vitro.

    Science.gov (United States)

    Nafiu, Mikhail Olugbemiro; Ashafa, Anofi Omotayo Tom

    2017-01-01

    Dianthus basuticus is a plant of South African origin with various acclaimed pharmaceutical potentials. This study explored the antioxidant and antidiabetic activities of saponin extract from D. basuticus in vitro . Antioxidant activity of saponin was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide (*NO)-free radical scavenging activity while antidiabetic potentials were measured by the α-amylase and α-glucosidase inhibitory activities of the saponin extract. The results showed that the saponin extract, compared with quercetin, displayed better DPPH (IC 50 = 6.95 mg/ml) and NO (IC 50 = 3.31 mg/ml) radical scavenging capabilities. Similarly, the saponin extracts elicited stronger α-glucosidase (IC 50 = 3.80 mg/ml) and moderate α-amylase (IC 50 = 4.18 mg/ml) inhibitory activities as compared to acarbose. Saponin exhibited a competitive mode of inhibition on α-amylase with same maximum velocity (Vmax) of 0.0093 mM/min for saponin compared with control 0.0095 mM/min and different the Michaelis constant (Km) values of 2.6 × 10 -6 mM and 2.1 × 10 -5 mM, respectively, while for α-glucosidase, the inhibition was uncompetitive, Vmax of 0.027 mM/min compared with control 0.039 mM/min and Km values of 1.02 × 10 -6 mM and 1.38 × 10 -6 mM, respectively. The gas chromatography-mass spectrometric analysis revealed the presence of bioactive like β- and α-amyrin, 3-O-methyl-D-glucose, methyl commate, and olean-12-en-3-beta-ol. Overall, the data suggested that the saponin extract from D. basuticus has potentials as natural antioxidants and antidiabetics. Saponin extract from Dianthus basuticus displayed promising antidiabetic and antioxidant activitySaponin competitively and uncompetitively inhibited a-amylase and a-glucosidase, respectivelyThe stronger inhibition of α-glucosidase and moderate inhibition of α-amylase by saponin extract from D. basuticus is promising good antidiabetes compared with existing drugs with associated side effects

  18. Effect of domestic cooking on the starch digestibility, predicted glycemic indices, polyphenol contents and alpha amylase inhibitory properties of beans (Phaseolis vulgaris) and breadfruit (Treculia africana).

    Science.gov (United States)

    Chinedum, E; Sanni, S; Theressa, N; Ebere, A

    2018-01-01

    The effect of processing on starch digestibility, predicted glycemic indices (pGI), polyphenol contents and alpha amylase inhibitory properties of beans (Phaseolis vulgaris) and breadfruit (Treculia africana) was studied. Total starch ranged from 4.3 to 68.3g/100g, digestible starch ranged from 4.3 to 59.2 to 65.7g/100g for the raw and processed legumes; Resistance starch was not detected in most of the legumes except in fried breadfruit and the starches in both the raw and processed breadfruit were more rapidly digested than those from raw and cooked beans. Raw and processed breadfruit had higher hydrolysis curves than raw and processed beans with the amylolysis level in raw breadfruit close to that of white bread. Raw beans had a low glycemic index (GI); boiled beans and breadfruit had intermediate glycemic indices respectively while raw and fried breadfruit had high glycemic indices. Aqueous extracts of the food samples had weak α-amylase inhibition compared to acarbose. The raw and processed legumes contained considerable amounts of dietary phenols and flavonoids. The significant correlation (r=0.626) between α-amylase inhibitory actions of the legumes versus their total phenolic contents suggests the contribution of the phenolic compounds in these legumes to their α-amylase inhibitory properties. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Anti-inflammatory and enzyme inhibitory activities of a crude extract and a pterocarpan isolated from the aerial parts of Vitex agnus-castus.

    Science.gov (United States)

    Ahmad, Bashir; Azam, Sadiq; Bashir, Shumaila; Khan, Ibrar; Adhikari, Achyut; Choudhary, Muhammad Iqbal

    2010-11-01

    A new compound, 6a,11a-dihydro-6H-[1] benzofuro [3,2-c][1,3]dioxolo[4,5-g]chromen-9-ol was isolated from the ethyl acetate fraction of Vitex agnus-castus. The structure of this compound was identified with the help of spectroscopic techniques ((13)C NMR, (1)H NMR, HMBC, HMQC, NOESY and COSY). The compound showed low urease- (32.0%) and chymotrypsin- (31.4%) inhibitory activity, and moderate (41.3%) anti-inflammatory activity. The crude extract and various fractions obtained from the aerial parts of the plant were also screened for possible in vitro hemagglutination, antibacterial and phytotoxic activities. No hemagglutination activity against human erythrocytes was observed in crude extracts and fractions of V. agnus-castus. The fractions and crude methanolic extract showed moderate and low antibacterial activity. Exceptions were the CHCl(3) fraction, which showed significant antibacterial activity against Klebsiella pneumonia (81% with MIC(50)=2.19 mg/mL), the n-hexane fraction, which exhibited no activity against Salmonella typhi, and the CHCl(3) and aqueous fractions, which showed no activity against Bacillus pumalis. Moderate phytotoxic activity (62.5%) was observed by n-hexane fraction of V. agnus-castus against Lemna minor L at 1000 μg/mL.

  20. Graphene immobilized enzyme/polyethersulfone mixed matrix membrane: Enhanced antibacterial, permeable and mechanical properties

    International Nuclear Information System (INIS)

    Duan, Linlin; Wang, Yuanming; Zhang, Yatao; Liu, Jindun

    2015-01-01

    Graphical abstract: - Highlights: • Lysozyme was immobilized on the surface of graphene oxide (GO) and reduced GO (RGO). • The novel hybrid membranes based on lysozyme and graphene were fabricated firstly. • These membranes showed good antibacterial and mechanical performance. - Abstract: Enzyme immobilization has been developed to address lots of issues of free enzyme, such as instability, low activity and difficult to retain. In this study, graphene was used as an ideal carrier for lysozyme immobilization, including graphene oxide (GO) immobilized lysozyme (GO-Ly) and chemically reduced graphene oxide (CRGO) immobilized lysozyme (CRGO-Ly). Herein, lysozyme as a bio-antibacterial agent has excellent antibacterial performance and the products of its catalysis are safety and nontoxic. Then the immobilized lysozyme materials were blended into polyethersulfone (PES) casting solution to prepare PES ultrafiltration membrane via phase inversion method. GO and CRGO were characterized by Fourier transform infrared spectroscopy (FTIR), Ultraviolet–visible spectrum (UV), X-ray diffraction (XRD), and transmission electron microscopy (TEM) and the immobilized lysozyme composites were observed by fluorescent microscopy. The results revealed that GO and CRGO were successfully synthesized and lysozyme was immobilized on their surfaces. The morphology, hydrophilicity, mechanical properties, separation properties and antibacterial activity of the hybrid membranes were characterized in detail. The hydrophilicity, water flux and mechanical strength of the hybrid membranes were significantly enhanced after adding the immobilized lysozyme. In the antibacterial experiment, the hybrid membranes exhibited an effective antibacterial performance against Escherichia coli (E. coli).

  1. Resistive switching memory properties of layer-by-layer assembled enzyme multilayers

    International Nuclear Information System (INIS)

    Baek, Hyunhee; Cho, Jinhan; Lee, Chanwoo; Lim, Kwang-il

    2012-01-01

    The properties of enzymes, which can cause reversible changes in currents through redox reactions in solution, are of fundamental and practical importance in bio-electrochemical applications. These redox properties of enzymes are often associated with their charge-trap sites. Here, we demonstrate that reversible changes in resistance in dried lysozyme (LYS) films can be generated by an externally applied voltage as a result of charge trap/release. Based on such changes, LYS can be used as resistive switching active material for nonvolatile memory devices. In this study, cationic LYS and anionic poly(styrene sulfonate) (PSS) layers were alternately deposited onto Pt-coated silicon substrates using a layer-by-layer assembly method. Then, top electrodes were deposited onto the top of LYS/PSS multilayers to complete the fabrication of the memory-like device. The LYS/PSS multilayer devices exhibited typical resistive switching characteristics with an ON/OFF current ratio above 10 2 , a fast switching speed of 100 ns and stable performance. Furthermore, the insertion of insulating polyelectrolytes (PEs) between the respective LYS layers significantly enhanced the memory performance of the devices showing a high ON/OFF current ratio of ∼10 6 and low levels of power consumption. (paper)

  2. Effect of Allium sativum and fish collagen on the proteolytic and angiotensin-I converting enzyme-inhibitory activities in cheese and yogurt.

    Science.gov (United States)

    Shori, A B; Baba, A S; Keow, J N

    2012-12-15

    There is an increasing demand of functional foods in developed countries. Yogurt plays an important role in the management of blood pressure. Several bioactive peptides isolated from Allium sativum or fish collagen have shown antihypertensive activity. Thus, in the present study the effects of A. sativum and/or Fish Collagen (FC) on proteolysis and ACE inhibitory activity in yogurt (0, 7 and 14 day) and cheese (0, 14 and 28 day) were investigated. Proteolytic activities were the highest on day 7 of refrigerated storage in A. sativum-FC-yogurt (337.0 +/- 5.3 microg g(-1)) followed by FC-yogurt (275.3 +/- 2.0 microg g(-1)), A. sativum-yogurt (245.8 +/- 4.2 microg g(-1)) and plain-yogurt (40.4 +/- 1.2 microg g(-1)). On the other hand, proteolytic activities in cheese ripening were the highest (p sativum-cheeses (411.4 +/- 4.3 and 528.7 +/- 1.6 microg g(-1), respectively). However, the presence of FC increased the proteolysis to the highest level on day 28 of storage for FC- and A. sativum-FC cheeses (641.2 +/- 0.1 and 1128.4 +/- 4.5 microg g(-1), respectively). In addition, plain- and A. sativum-yogurts with or without FC showed maximal inhibition of ACE on day 7 of storage. Fresh plain- and A. sativum-cheeses showed ACE inhibition (72.3 +/- 7.8 and 50.4 +/- 1.6 % respectively), the presence of FC in both type of cheeses reduced the ACE inhibition to 62.9 +/- 0.8 and 44.5 +/- 5.0%, respectively. However, refrigerated storage increased ACE inhibition in cheeses (p sativum-yogurt or cheese enhanced the proteolytic activity. Thus, it has potential in the development of an effective dietary strategy for hypertension associated cardiovascular diseases.

  3. Application of the Kombucha 'tea fungus' for the enhancement of antioxidant and starch hydrolase inhibitory properties of ten herbal teas.

    Science.gov (United States)

    Watawana, Mindani I; Jayawardena, Nilakshi; Choo, Candy; Waisundara, Viduranga Y

    2016-03-01

    Ten herbal teas (Acacia arabica, Aegle marmelos flower, A. marmelos root bark, Aerva lanata, Asteracantha longifolia, Cassia auriculata, Hemidesmus indicus, Hordeum vulgare, Phyllanthus emblica, Tinospora cordifolia) were fermented with the Kombucha 'tea fungus'. The pH values of the fermented beverages ranged from 4.0 to 6.0 by day 7, while the titratable acidity ranged from 2.5 to 5.0g/mL (PKombucha beverages to have statistically significant increases (P<0.05) by day 7. The α-amylase inhibitory activities ranged from 52.5 to 67.2μg/mL in terms of IC50 values following fermentation, while the α-glucosidase inhibitory activities ranged from 95.2 to 196.1μg/mL. In conclusion, an enhancement of the antioxidant and starch hydrolase inhibitory potential of the herbal teas was observed by adding the tea fungus. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Phlorotannin Extracts from Fucales Characterized by HPLC-DAD-ESI-MSn: Approaches to Hyaluronidase Inhibitory Capacity and Antioxidant Properties

    Science.gov (United States)

    Ferreres, Federico; Lopes, Graciliana; Gil-Izquierdo, Angel; Andrade, Paula B.; Sousa, Carla; Mouga, Teresa; Valentão, Patrícia

    2012-01-01

    Purified phlorotannin extracts from four brown seaweeds (Cystoseira nodicaulis (Withering) M. Roberts, Cystoseira tamariscifolia (Hudson) Papenfuss, Cystoseira usneoides (Linnaeus) M. Roberts and Fucus spiralis Linnaeus), were characterized by HPLC-DAD-ESI-MSn. Fucophloroethol, fucodiphloroethol, fucotriphloroethol, 7-phloroeckol, phlorofucofuroeckol and bieckol/dieckol were identified. The antioxidant activity and the hyaluronidase (HAase) inhibitory capacity exhibited by the extracts were also assessed. A correlation between the extracts activity and their chemical composition was established. F. spiralis, the species presenting higher molecular weight phlorotannins, generally displayed the strongest lipid peroxidation inhibitory activity (IC50 = 2.32 mg/mL dry weight) and the strongest HAase inhibitory capacity (IC50 = 0.73 mg/mL dry weight). As for superoxide radical scavenging, C. nodicaulis was the most efficient species (IC50 = 0.93 mg/mL dry weight), followed by F. spiralis (IC50 = 1.30 mg/mL dry weight). These results show that purified phlorotannin extracts have potent capabilities for preventing and slowing down the skin aging process, which is mainly associated with free radical damage and with the reduction of hyaluronic acid concentration, characteristic of the process. PMID:23222802

  5. Assessment of Soil Health in Urban Agriculture: Soil Enzymes and Microbial Properties

    Directory of Open Access Journals (Sweden)

    Avanthi Deshani Igalavithana

    2017-02-01

    Full Text Available Urban agriculture has been recently highlighted with the increased importance for recreation in modern society; however, soil quality and public health may not be guaranteed because of continuous exposure to various pollutants. The objective of this study was to evaluate the soil quality of urban agriculture by soil microbial assessments. Two independent variables, organic and inorganic fertilizers, were considered. The activities of soil enzymes including dehydrogenase, β-glucosidase, arylsulfatase, urease, alkaline and acid phosphatases were used as indicators of important microbial mediated functions and the soil chemical properties were measured in the soils applied with organic or inorganic fertilizer for 10 years. Fatty acid methyl ester analysis was applied to determine the soil microbial community composition. Relatively higher microbial community richness and enzyme activities were found in the organic fertilizers applied soils as compared to the inorganic fertilizers applied soils. Principal component analysis explained the positive influence of organic fertilizers on the microbial community. The application of organic fertilizers can be a better alternative compared to inorganic fertilizers for the long-term health and security of urban agriculture.

  6. Bioactive properties of commercialised pomegranate (Punica granatum) juice: antioxidant, antiproliferative and enzyme inhibiting activities.

    Science.gov (United States)

    Les, Francisco; Prieto, Jose M; Arbonés-Mainar, Jose Miguel; Valero, Marta Sofía; López, Víctor

    2015-06-01

    Pomegranate juice and related products have long been used either in traditional medicine or as nutritional supplements claiming beneficial effects. Although there are several studies on this food plant, only a few studies have been performed with pomegranate juice or marketed products. The aim of this work is to evaluate the antioxidant effects of pomegranate juice on cellular models using hydrogen peroxide as an oxidizing agent or DPPH and superoxide radicals in cell free systems. The antiproliferative effects of the juice were measured on HeLa and PC-3 cells by the MTT assay and pharmacologically relevant enzymes (cyclooxygenases, xanthine oxidase, acetylcholinesterase and monoamine oxidase A) were selected for enzymatic inhibition assays. Pomegranate juice showed significant protective effects against hydrogen peroxide induced toxicity in the Artemia salina and HepG2 models; these effects may be attributed to radical scavenging properties of pomegranate as the juice was able to reduce DPPH and superoxide radicals. Moderate antiproliferative activities in HeLa and PC-3 cancer cells were observed. However, pomegranate juice was also able to inhibit COX-2 and MAO-A enzymes. This study reveals some mechanisms by which pomegranate juice may have interesting and beneficial effects in human health.

  7. The inhibitory effect of an extract of Sanguisorba officinalis L. on ultraviolet B-induced pigmentation via the suppression of endothelin-converting enzyme-1{alpha}

    Energy Technology Data Exchange (ETDEWEB)

    Hachiya, Akira; Kobayashi, Akemi; Ohuchi, Atsushi; Kitahara, Takashi; Takema, Yoshinori [Kao Biological Science Lab., Ichikai, Tochigi (Japan)

    2001-06-01

    Endothelin-1 (ET-1) has been reported to be expressed in human epidermis at both the gene and protein levels. ET-1 plays a pivotal role in ultraviolet B (UVB)-induced pigmentation due to its accentuated secretion after UVB irradiation and its function as a mitogen and as a melanogen for human melanocytes. We have recently found that endothelin-converting enzyme (ECE)-1{alpha} plays a constitutive role in the secretion of ET-1 by human keratinocytes and that an extract of Sanguisorba officinalis L. inhibits ECE activity in human endothelial cells, which predominantly express ECE-1{alpha}. In this report, to clarify the potential use of this botanical extract as a whitening agent, we examined whether this extract inhibits UVB-induced pigmentation in vivo. When this extract was applied to human keratinocytes after UVB irradiation, secretion of ET-1 by those cells was reduced, and this was accompanied by a concomitant increase in the secretion of inactive precursor Big endothelin-1. When hairless mice were exposed to UVB light and were treated with the extract, it suppressed the induction of ET-1 in the UVB-irradiated epidermis. In the course of UVB-induced pigmentation of brownish guinea pig skin, this extract significantly diminished pigmentation in UVB-exposed areas. These findings indicate that ECE-1{alpha} in keratinocytes plays a pivotal role in the induction of pigmentation following UVB irradiation and that an extract of S. officinalis, which inhibits ET-1 production in human keratinocytes, is a good ingredient for a whitening agent. (author)

  8. The inhibitory effect of an extract of Sanguisorba officinalis L. on ultraviolet B-induced pigmentation via the suppression of endothelin-converting enzyme-1α

    International Nuclear Information System (INIS)

    Hachiya, Akira; Kobayashi, Akemi; Ohuchi, Atsushi; Kitahara, Takashi; Takema, Yoshinori

    2001-01-01

    Endothelin-1 (ET-1) has been reported to be expressed in human epidermis at both the gene and protein levels. ET-1 plays a pivotal role in ultraviolet B (UVB)-induced pigmentation due to its accentuated secretion after UVB irradiation and its function as a mitogen and as a melanogen for human melanocytes. We have recently found that endothelin-converting enzyme (ECE)-1α plays a constitutive role in the secretion of ET-1 by human keratinocytes and that an extract of Sanguisorba officinalis L. inhibits ECE activity in human endothelial cells, which predominantly express ECE-1α. In this report, to clarify the potential use of this botanical extract as a whitening agent, we examined whether this extract inhibits UVB-induced pigmentation in vivo. When this extract was applied to human keratinocytes after UVB irradiation, secretion of ET-1 by those cells was reduced, and this was accompanied by a concomitant increase in the secretion of inactive precursor Big endothelin-1. When hairless mice were exposed to UVB light and were treated with the extract, it suppressed the induction of ET-1 in the UVB-irradiated epidermis. In the course of UVB-induced pigmentation of brownish guinea pig skin, this extract significantly diminished pigmentation in UVB-exposed areas. These findings indicate that ECE-1α in keratinocytes plays a pivotal role in the induction of pigmentation following UVB irradiation and that an extract of S. officinalis, which inhibits ET-1 production in human keratinocytes, is a good ingredient for a whitening agent. (author)

  9. Application of enzymes for efficient extraction, modification, and development of functional properties of lime pectin

    DEFF Research Database (Denmark)

    Dominiak, Malgorzata Maria; Marie Søndergaard, Karen; Wichmann, Jesper

    2014-01-01

    pectin. The most efficient enzyme preparation was Laminex C2K derived from Penicillium funiculosum which, during 4 h treatment at pH 3.5, 50 °C, released pectin with similar yield (23% w/w), molecular weight (69 kDa), and functional properties e.g. gelling, stabilization of acidified milk drinks...... and viscosity as the classically acid-extracted pectins (8 h treatment at 70 °C, pH ... at higher temperatures. The Laminex CK2 extracted pectin polymers were not sensitive to the presence of Ca2+ ions, they formed a gel at low pH in the presence of sugar and were able to stabilize acidified milk drinks. Further modification by enzymatic de-esterification of the pectin extracted with Laminex C...

  10. Inhibitory Effects of Commonly Used Herbal Extracts on UDP-Glucuronosyltransferase 1A4, 1A6, and 1A9 Enzyme Activities

    Science.gov (United States)

    Mohamed, Mohamed-Eslam F.

    2011-01-01

    The aim of this study was to investigate the effect of commonly used botanicals on UDP-glucuronosyltransferase (UGT) 1A4, UGT1A6, and UGT1A9 activities in human liver microsomes. The extracts screened were black cohosh, cranberry, echinacea, garlic, ginkgo, ginseng, milk thistle, saw palmetto, and valerian in addition to the green tea catechin epigallocatechin gallate (EGCG). Formation of trifluoperazine glucuronide, serotonin glucuronide, and mycophenolic acid phenolic glucuronide was used as an index reaction for UGT1A4, UGT1A6, and UGT1A9 activities, respectively, in human liver microsomes. Inhibition potency was expressed as the concentration of the inhibitor at 50% activity (IC50) and the volume in which the dose could be diluted to generate an IC50-equivalent concentration [volume/dose index (VDI)]. Potential inhibitors were EGCG for UGT1A4, milk thistle for both UGT1A6 and UGT1A9, saw palmetto for UGT1A6, and cranberry for UGT1A9. EGCG inhibited UGT1A4 with an IC50 value of (mean ± S.E.) 33.8 ± 3.1 μg/ml. Milk thistle inhibited both UGT1A6 and UGT1A9 with IC50 values of 59.5 ± 3.6 and 33.6 ± 3.1 μg/ml, respectively. Saw palmetto and cranberry weakly inhibited UGT1A6 and UGT1A9, respectively, with IC50 values >100 μg/ml. For each inhibition, VDI was calculated to determine the potential of achieving IC50-equivalent concentrations in vivo. VDI values for inhibitors indicate a potential for inhibition of first-pass glucuronidation of UGT1A4, UGT1A6, and UGT1A9 substrates. These results highlight the possibility of herb-drug interactions through modulation of UGT enzyme activities. Further clinical studies are warranted to investigate the in vivo extent of the observed interactions. PMID:21632963

  11. Identification and structural analysis of an L-asparaginase enzyme from guinea pig with putative tumor cell killing properties.

    Science.gov (United States)

    Schalk, Amanda M; Nguyen, Hien-Anh; Rigouin, Coraline; Lavie, Arnon

    2014-11-28

    The initial observation that guinea pig serum kills lymphoma cells marks the serendipitous discovery of a new class of anti-cancer agents. The serum cell killing factor was shown to be an enzyme with L-asparaginase (ASNase) activity. As a direct result of this observation, several bacterial L-asparaginases were developed and are currently approved by the Food and Drug Administration for the treatment of the subset of hematological malignancies that are dependent on the extracellular pool of the amino acid asparagine. As drugs, these enzymes act to hydrolyze asparagine to aspartate, thereby starving the cancer cells of this amino acid. Prior to the work presented here, the precise identity of this guinea pig enzyme has not been reported in the peer-reviewed literature. We discovered that the guinea pig enzyme annotated as H0W0T5_CAVPO, which we refer to as gpASNase1, has the required low Km property consistent with that possessed by the cell-killing guinea pig serum enzyme. Elucidation of the ligand-free and aspartate complex gpASNase1 crystal structures allows a direct comparison with the bacterial enzymes and serves to explain the lack of L-glutaminase activity in the guinea pig enzyme. The structures were also used to generate a homology model for the human homolog hASNase1 and to help explain its vastly different kinetic properties compared with gpASNase1, despite a 70% sequence identity. Given that the bacterial enzymes frequently present immunogenic and other toxic side effects, this work suggests that gpASNase1 could be a promising alternative to these bacterial enzymes. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  12. In Situ Earthworm Breeding to Improve Soil Aggregation, Chemical Properties, and Enzyme Activity in Papayas

    Directory of Open Access Journals (Sweden)

    Huimin Xiang

    2018-04-01

    Full Text Available The long-term use of mineral fertilizers has decreased the soil fertility in papaya (Carica papaya L. orchards in South China. In situ earthworm breeding is a new sustainable practice for improving soil fertility. A field experiment was conducted to compare the effects of four treatments consisting of the control (C, chemical fertilizer (F, compost (O, and in situ earthworm breeding (E on soil physico-chemical properties and soil enzyme activity in a papaya orchard. The results showed that soil chemical properties, such as pH, soil organic matter (SOM, total nitrogen (TN, available nitrogen (AN, and total phosphorus (TP were significantly improved with the E treatment but declined with the F treatment. On 31 October 2008, the SOM and TN with the O and E treatments were increased by 26.3% and 15.1%, respectively, and by 32.5% and 20.6% compared with the F treatment. Furthermore, the O and E treatments significantly increased the activity of soil urease and sucrase. Over the whole growing season, soil urease activity was 34.4%~40.4% and 51.1%~58.7% higher with the O and E treatments, respectively, than that with the C treatment. Additionally, the activity of soil sucrase with the E treatment was always the greatest of the four treatments, whereas the F treatment decreased soil catalase activity. On 11 June 2008 and 3 July 2008, the activity of soil catalase with the F treatment was decreased by 19.4% and 32.0% compared with C. Soil bulk density with the four treatments was in the order of O ≤ E < F < C. The O- and E-treated soil bulk density was significantly lower than that of the F-treated soil. Soil porosity was in the order of C < F < E < O. Soil porosity with the O and E treatments was 6.0% and 4.7% higher, respectively, than that with the F treatment. Meanwhile, the chemical fertilizer applications significantly influenced the mean weight diameter (MWD of the aggregate and proportion of different size aggregate fractions. The E treatment

  13. Mono-N-acyl-2,6-diaminopimelic acid derivatives: analysis by electromigration and spectroscopic methods and examination of enzyme inhibitory activity.

    Science.gov (United States)

    Hlaváček, Jan; Vítovcová, Miloslava; Sázelová, Petra; Pícha, Jan; Vaněk, Václav; Buděšínský, Miloš; Jiráček, Jiří; Gillner, Danuta M; Holz, Richard C; Mikšík, Ivan; Kašička, Václav

    2014-12-15

    Thirteen mono-N-acyl derivatives of 2,6-diaminopimelic acid (DAP)-new potential inhibitors of the dapE-encoded N-succinyl-l,l-diaminopimelic acid desuccinylase (DapE; EC 3.5.1.18)-were analyzed and characterized by infrared (IR) and nuclear magnetic resonance (NMR) spectroscopies and two capillary electromigration methods: capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography (MEKC). Structural features of DAP derivatives were characterized by IR and NMR spectroscopies, whereas CZE and MEKC were applied to evaluate their purity and to investigate their electromigration properties. Effective electrophoretic mobilities of these compounds were determined by CZE in acidic and alkaline background electrolytes (BGEs) and by MEKC in acidic and alkaline BGEs containing a pseudostationary phase of anionic detergent sodium dodecyl sulfate (SDS) or cationic detergent cetyltrimethylammonium bromide (CTAB). The best separation of DAP derivatives, including diastereomers of some of them, was achieved by MEKC in an acidic BGE (500 mM acetic acid [pH 2.54] and 60mM SDS). All DAP derivatives were examined for their ability to inhibit catalytic activity of DapE from Haemophilus influenzae (HiDapE) and ArgE from Escherichia coli (EcArgE). None of these DAP derivatives worked as an effective inhibitor of HiDapE, but one derivative-N-fumaryl, Me-ester-DAP-was found to be a moderate inhibitor of EcArgE, thereby providing a promising lead structure for further studies on ArgE inhibitors. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Endoglucanase enzyme protein engineering by site-directed mutagenesis to improve the enzymatic properties and its expression in yeast

    Directory of Open Access Journals (Sweden)

    Farnaz Nikzad Jamnani

    2013-11-01

    Full Text Available Introduction: Fossil fuel is an expensive and finite energy source. Therefore, the use of renewable energy and biofuels production has been taken into consideration. One of the most suitable raw materials for biofuels is cellulosic compounds. Only microorganisms that contain cellulose enzymes can decompose cellulose and fungus of Trichodermareesei is the most important producer of this enzyme. Methods: In this study the nucleotide sequence of endoglucanase II, which is the starter of attack to cellulose chains, synthesized from amino acid sequence of this enzyme in fungus T.reesei and based on codon usage in the host; yeast Pichiapastoris. To produce optimized enzyme and to decrease the production time and enzyme price, protein engineering will be used. There are some methods to improve the enzymatic properties like site-directed mutagenesis in which amino-acid replacement occur. In this study two mutations were induced in endoglucanase enzyme gene by PCR in which free syctein positions 169 and 393 were switched to valine and histidine respectively. Then this gene was inserted into the pPinka expression vector and cloned in Escherichia coli. The recombinant plasmids were transferred into P.pastoris competent cells with electroporation, recombinant yeasts were cultured in BMMY medium and induced with methanol. Results: The sequencing of gene proved the induction of the two mutations and the presence of recombinant enzyme was confirmed by dinitrosalicilic acid method and SDS-PAGE. Conclusion: Examination of biochemical properties revealed that the two mutations simultaneously decreased catalytic power, thermal stability and increased the affinity of enzyme and substrate.

  15. Improving oral bioavailability of resveratrol by a UDP-glucuronosyltransferase inhibitory excipient-based self-microemulsion.

    Science.gov (United States)

    Yang, Fei-Fei; Zhou, Jing; Hu, Xiao; Cong, Zhao-Qing; Liu, Chun-Yu; Pan, Rui-Le; Chang, Qi; Liu, Xin-Min; Liao, Yong-Hong

    2018-03-01

    Self-microemulsifying (SME) drug delivery system has been developed to increase oral bioavailabilities, and inhibitory excipients are capable of improving oral bioavailability by inhibiting enzyme mediated intestinal metabolism. However, the potential of enzyme inhibitory excipients containing SME in boosting resveratrol bioavailability remains largely uninvestigated. In this study, we set out to prepare SME-1 with UGT inhibitory excipients (excipients without inhibitory activities named SME-2 as control) to increase the bioavailability of RES by inhibiting intestinal metabolism. Results demonstrated that similar physicochemical properties such as size, polydistribution index and in vitro release, cellular uptake and permeability in Caco-2 cells as well as in vivo lymphatic distribution between inhibitory SME-1 and non-inhibitory SME-2 were observed. In vivo study demonstrated that the molar ratios of RES-G/RES were 7.25±0.48 and 5.06±2.42 for free drug and SME-2, respectively, and the molar ratio decreased to 0.36±0.10 in SME-1 group. Pharmacokinetic study confirmed that the inhibitory excipients containing SME demonstrated potential in increasing bioavailability of RES from 6.5% for the free RES and 12.9% for SME-2 to 76.1% in SME-1 through modulating the glucuronidation by UGT inhibitory excipients. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. Ultrasound assisted intensification of enzyme activity and its properties: a mini-review.

    Science.gov (United States)

    Nadar, Shamraja S; Rathod, Virendra K

    2017-08-22

    Over the last decade, ultrasound technique has emerged as the potential technology which shows large applications in food and biotechnology processes. Earlier, ultrasound has been employed as a method of enzyme inactivation but recently, it has been found that ultrasound does not inactivate all enzymes, particularly, under mild conditions. It has been shown that the use of ultrasonic treatment at appropriate frequencies and intensity levels can lead to enhanced enzyme activity due to favourable conformational changes in protein molecules without altering its structural integrity. The present review article gives an overview of influence of ultrasound irradiation parameters (intensity, duty cycle and frequency) and enzyme related factors (enzyme concentration, temperature and pH) on the catalytic activity of enzyme during ultrasound treatment. Also, it includes the effect of ultrasound on thermal kinetic parameters and Michaelis-Menten kinetic parameters (k m and V max ) of enzymes. Further, in this review, the physical and chemical effects of ultrasound on enzyme have been correlated with thermodynamic parameters (enthalpy and entropy). Various techniques used for investigating the conformation changes in enzyme after sonication have been highlighted. At the end, different techniques of immobilization for ultrasound treated enzyme have been summarized.

  17. Exploiting Unique Structural and Functional Properties of Malarial Glycolytic Enzymes for Antimalarial Drug Development

    Directory of Open Access Journals (Sweden)

    Asrar Alam

    2014-01-01

    Full Text Available Metabolic enzymes have been known to carry out a variety of functions besides their normal housekeeping roles known as “moonlighting functions.” These functionalities arise from structural changes induced by posttranslational modifications and/or binding of interacting proteins. Glycolysis is the sole source of energy generation for malaria parasite Plasmodium falciparum, hence a potential pathway for therapeutic intervention. Crystal structures of several P. falciparum glycolytic enzymes have been solved, revealing that they exhibit unique structural differences from the respective host enzymes, which could be exploited for their selective targeting. In addition, these enzymes carry out many parasite-specific functions, which could be of potential interest to control parasite development and transmission. This review focuses on the moonlighting functions of P. falciparum glycolytic enzymes and unique structural differences and functional features of the parasite enzymes, which could be exploited for therapeutic and transmission blocking interventions against malaria.

  18. Evaluation of Antioxidant, Cholinesterase Inhibitory and Antimicrobial Properties of Mentha longifolia subsp. noeana and Its Secondary Metabolites

    Directory of Open Access Journals (Sweden)

    Abdulselam Ertaş

    2015-01-01

    Full Text Available The aim of the present study was to determine the chemical structures of the isolated compounds, the essential oil and fatty acid compositions of Mentha longifolia subsp. noeana with their biological activities. Ursolic acid (1, u vaol (2, stigmast-5-ene-3 b -yl formate (3, stigmast-5-en-3-one (4, b -sitosterol (5, bis(2-ethylhexyl benzene-1,2-dicarboxylate (6,hexacosyl (E-ferulate (7 and 5-hydroxy-6,7,3',4'-tetramethoxy flavone (8 were obtained from the aerial parts. The compounds (2-4, 6, 7 were isolated for the first time from a Mentha species. Palmitic acid (40.8% was the major component of the non-polar fraction obtained from the petroleum ether extract. Pulegone (32.3% was the main constituent of the essential oil which exhibited strong butyrylcholinesterase inhibitory activity (77.36 ± 0.29%, moderate antimicrobial activity against Escherichia coli, Staphylococcus aureus, and Candida albicans. The methanol extract showed 80% inhibition of lipid peroxidation, and the acetone extract possessed moderate DPPH free radical scavenging activity (60% inhibition at 100 m g/mL.

  19. Breast Cancer Stem Cell Therapeutics, Multiple Strategies Versus Using Engineered Mesenchymal Stem Cells With Notch Inhibitory Properties: Possibilities and Perspectives.

    Science.gov (United States)

    Bose, Bipasha; Sen, Utsav; Shenoy P, Sudheer

    2018-01-01

    Relapse cases of cancers are more vigorous and difficult to control due to the preponderance of cancer stem cells (CSCs). Such CSCs that had been otherwise dormant during the first incidence of cancer gradually appear as radiochemoresistant cancer cells. Hence, cancer therapeutics aimed at CSCs would be an effective strategy for mitigating the cancers during relapse. Alternatively, CSC therapy can also be proposed as an adjuvant therapy, along-with the conventional therapies. As regenerative stem cells (RSCs) are known for their trophic effects, anti-tumorogenicity, and better migration toward an injury site, this review aims to address the use of adult stem cells such as dental pulp derived; cord blood derived pure populations of regenerative stem cells for targeting CSCs. Indeed, pro-tumorogenicity of RSCs is of concern and hence has also been dealt with in relation to breast CSC therapeutics. Furthermore, as notch signaling pathways are upregulated in breast cancers, and anti-notch antibody based and sh-RNA based therapies are already in the market, this review focuses the possibilities of engineering RSCs to express notch inhibitory proteins for breast CSC therapeutics. Also, we have drawn a comparison among various possibilities of breast CSC therapeutics, about, notch1 inhibition. J. Cell. Biochem. 119: 141-149, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  20. Evaluation of the sensor properties of the pH-static enzyme sensor

    NARCIS (Netherlands)

    van der Schoot, B.H.; van der Schoot, Bart H.; Bergveld, Piet

    1990-01-01

    The pH-static enzyme sensor consists of a chemical sensor-actuator system covered with a thin enzyme-entrapping membrane. By the electrochemical generation of protons or hydroxyl ions, pH changes induced by the conversion of a substrate by the enzymatic reaction are compensated. The pH inside the

  1. Purification and properties of amylolytic enzyme from Aspergillus oryzae MIBA316

    OpenAIRE

    仮屋, 麻紀子; 矢野, めぐむ; 瀧井, 幸男; Makiko, Kariya; Megumu, Yano; Yukio, Takii

    2003-01-01

    Amylolytic enzyme was purified to electrophoretically homogeneous state from culture broth of Aspergillus oryzae MIBA316. This enzyme hydrolyzed preferentially amylopectin, starch and glycogen. Approaches to complete breakdown of starch to its components and their utilization in food processing were discussed.

  2. Porous chitosan beads of superior mechanical properties for the covalent immobilization of enzymes.

    Science.gov (United States)

    Wahba, Marwa I

    2017-12-01

    Porous chitosan beads of superior mechanical properties were produced via a two stepped treatment process. First, the chitosan ionotropic gelation solution was supplemented with Na 2 CO 3 , which acted as a porogen. Afterwards, the beads were chemically cross-linked with glutaraldehyde. This treatment also caused the produced porous chitosan beads to acquire higher observed activities of immobilized β-d-galactosidase (β-gal). The observed activities of the β-gal immobilized onto the 0.2M and the 0.35M Na 2 CO 3 treated beads were 1.63 and 1.91 fold respectively, higher than the activity offered by the control beads. Nevertheless, both the control beads and the 0.2M Na 2 CO 3 beads caused the optimum pH range of β-gal to shift from 4.6-5.1 to ∼2.7-5. The enzyme's optimum temperature shifted from 55 to 60°C after its immobilization onto the control chitosan beads whereas the β-gal immobilized onto the 0.2M Na 2 CO 3 chitosan beads exhibited a temperature optimum of 55-60°C. The reusability study revealed the superiority of the 0.2M Na 2 CO 3 treated beads which retained 59.1% of their initial activity during the 13th enzymatic cycle. On the other hand, the control chitosan beads were fragmented and lost their activity after only four enzymatic cycles. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Copper stressed anaerobic fermentation: biogas properties, process stability, biodegradation and enzyme responses.

    Science.gov (United States)

    Hao, He; Tian, Yonglan; Zhang, Huayong; Chai, Yang

    2017-12-01

    The effect of copper (added as CuCl 2 ) on the anaerobic co-digestion of Phragmites straw and cow dung was studied in pilot experiments by investigating the biogas properties, process stability, substrate degradation and enzyme activities at different stages of mesophilic fermentation. The results showed that 30 and 100 mg/L Cu 2+ addition increased the cumulative biogas yields by up to 43.62 and 20.77% respectively, and brought forward the daily biogas yield peak, while 500 mg/L Cu 2+ addition inhibited biogas production. Meanwhile, the CH 4 content in the 30 and 100 mg/L Cu 2+ -added groups was higher than that in the control group. Higher pH values (close to pH 7) and lower oxidation-reduction potential (ORP) values in the Cu 2+ -added groups after the 8th day indicated better process stability compared to the control group. In the presence of Cu 2+ , the degradation of volatile fatty acids (VFAs) and other organic molecules (represented by chemical oxygen demand, COD) generated from hydrolysis was enhanced, and the ammonia nitrogen (NH 4 + -N) concentrations were more stable than in the control group. The contents of lignin and hemicellulose in the substrate declined in the Cu 2+ -added groups while the cellulose contents did not. Neither the cellulase nor the coenzyme F 420 activities could determine the biogas producing efficiency. Taking the whole fermentation process into account, the promoting effect of Cu 2+ addition on biogas yields was mainly attributable to better process stability, the enhanced degradation of lignin and hemicellulose, the transformation of intermediates into VFA, and the generation of CH 4 from VFA.

  4. Enzymes in cleaning products: an overview of toxicological properties and risk assessment/management.

    Science.gov (United States)

    Basketter, David; Berg, Ninna; Broekhuizen, Cees; Fieldsend, Mark; Kirkwood, Sheila; Kluin, Cornelia; Mathieu, Sophie; Rodriguez, Carlos

    2012-10-01

    Enzymes used in cleaning products have an excellent safety profile, with little ability to cause adverse responses in humans. For acute toxicity, genotoxicity, sub-acute and repeated dose toxicity, enzymes are unremarkable. Reproductive toxicity and carcinogenicity are also not endpoints of concern. Exceptions are the ability of some proteases to produce irritating effects at high concentrations and more importantly, the intrinsic potential of these bacterial/fungal proteins to act as respiratory sensitizers. It is a reasonable assumption that the majority of enzyme proteins possess this hazard. However, methods for characterising the respiratory sensitisation hazard of enzymes are lacking and the information required for risk assessment and risk management, although sufficient, remains limited. Previously, most data was generated in animal models and in in vitro immunoassays that assess immunological cross-reactivity. Nevertheless, by the establishment of strict limits on airborne exposure (based on a defined minimal effect limit of 60ng active enzyme protein/m(3)) and air and health monitoring, occupational safety can be assured. Similarly, by ensuring that airborne exposure is kept similarly low, coupled with knowledge of the fate of these enzymes on skin and fabrics, it has proven possible to establish a long history of safe consumer use of enzyme containing products. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Secretion of acid phosphatase by axenic Entamoeba histolytica NIH-200 and properties of the extracellular enzyme.

    Science.gov (United States)

    Agrawal, A; Pandey, V C; Kumar, S; Sagar, P

    1989-01-01

    Entamoeba histolytica (NIH-200) secreted large amounts of acid phosphatase in its external environment when grown axenically in modified TPS-II medium. Fractionation by DEAE-cellulose chromatography of the precipitate obtained from the cell-free medium at 60% ammonium sulfate saturation yielded 3 distinct peaks of enzyme activity. The enzyme in all the peaks showed resistance to tartrate but was inhibited by fluoride, cupric chloride, ethylene diamine-tetra acetic acid, ammonium molybdate and cysteine; however, enzyme associated with different peaks differed in its polyacrylamide gel electrophoretic profiles and behavior towards concanavalin A.

  6. Inhibitory effect of burdock leaves on elastase and tyrosinase activity

    Science.gov (United States)

    Horng, Chi-Ting; Wu, Hsing-Chen; Chiang, Ni-Na; Lee, Chiu-Fang; Huang, Yu-Syuan; Wang, Hui-Yun; Yang, Jai-Sing; Chen, Fu-An

    2017-01-01

    Burdock (Arctium lappa L.) leaves generate a considerable amount of waste following burdock root harvest in Taiwan. To increase the use of burdock leaves, the present study investigated the optimal methods for producing burdock leaf extract (BLE) with high antioxidant polyphenolic content, including drying methods and solvent extraction concentration. In addition, the elastase and tyrosinase inhibitory activity of BLE was examined. Burdock leaves were dried by four methods: Shadow drying, oven drying, sun drying and freeze-drying. The extract solution was then subjected to total polyphenol content analysis and the method that produced BLE with the highest amount of total antioxidant components was taken forward for further analysis. The 1,1-diphenyl-2-pycrylhydrazyl scavenging, antielastase and antityrosinase activity of the BLE were measured to enable the evaluation of the antioxidant and skin aging-associated enzyme inhibitory activities of BLE. The results indicated that the total polyphenolic content following extraction with ethanol (EtOH) was highest using the freeze-drying method, followed by the oven drying, shadow drying and sun drying methods. BLE yielded a higher polyphenol content and stronger antioxidant activity as the ratio of the aqueous content of the extraction solvent used increased. BLE possesses marked tyrosinase and elastase inhibitory activities, with its antielastase activity notably stronger compared with its antityrosinase activity. These results indicate that the concentration of the extraction solvent was associated with the antioxidant and skin aging-associated enzyme inhibitory activity of BLE. The reactive oxygen species scavenging theory of skin aging may explain the tyrosinase and elastase inhibitory activity of BLE. In conclusion, the optimal method for obtaining BLE with a high antioxidant polyphenolic content was freeze-drying followed by 30–50% EtOH extraction. In addition, the antielastase and antityrosinase activities of the

  7. Response of soil physicochemical properties and enzyme activities to long-term reclamation of coastal saline soil, Eastern China.

    Science.gov (United States)

    Xie, Xuefeng; Pu, Lijie; Wang, Qiqi; Zhu, Ming; Xu, Yan; Zhang, Meng

    2017-12-31

    Soil enzyme activity during different years of reclamation and land use patterns could indicate changes in soil quality. The objective of this research is to explore the dynamics of 5 soil enzyme activities (dehydrogenase, amylase, urease, acid phosphatase and alkaline phosphatase) involved in C, N, and P cycling and their responses to changes in soil physicochemical properties resulting from long-term reclamation of coastal saline soil. Soil samples from a total of 55 sites were collected from a coastal reclamation area with different years of reclamation (0, 7, 32, 40, 63a) in this study. The results showed that both long-term reclamation and land use patterns have significant effects on soil physicochemical properties and enzyme activities. Compared with the bare flat, soil water content, soil bulk density, pH and electrical conductivity showed a decreasing trend after reclamation, whereas soil organic carbon, total nitrogen and total phosphorus tended to increase. Dehydrogenase, amylase and acid phosphatase activities initially increased and then decreased with increasing years of reclamation, whereas urease and alkaline phosphatase activities were characterized by an increase-decrease-increase trend. Moreover, urease, acid phosphatase and alkaline phosphatase activities exhibited significant differences between coastal saline soil with 63years of reclamation and bare flat, whereas dehydrogenase and amylase activities remained unchanged. Aquaculture ponds showed higher soil water content, pH and EC but lower soil organic carbon, total nitrogen and total phosphorus than rapeseed, broad bean and wheat fields. Rapeseed, broad bean and wheat fields displayed higher urease and alkaline phosphatase activities and lower dehydrogenase, amylase and acid phosphatase activities compared with aquaculture ponds. Redundancy analysis revealed that the soil physicochemical properties explained 74.5% of the variation in soil enzyme activities and that an obvious relationship

  8. Exploring functionally related enzymes using radially distributed properties of active sites around the reacting points of bound ligands

    Directory of Open Access Journals (Sweden)

    Ueno Keisuke

    2012-04-01

    Full Text Available Abstract Background Structural genomics approaches, particularly those solving the 3D structures of many proteins with unknown functions, have increased the desire for structure-based function predictions. However, prediction of enzyme function is difficult because one member of a superfamily may catalyze a different reaction than other members, whereas members of different superfamilies can catalyze the same reaction. In addition, conformational changes, mutations or the absence of a particular catalytic residue can prevent inference of the mechanism by which catalytic residues stabilize and promote the elementary reaction. A major hurdle for alignment-based methods for prediction of function is the absence (despite its importance of a measure of similarity of the physicochemical properties of catalytic sites. To solve this problem, the physicochemical features radially distributed around catalytic sites should be considered in addition to structural and sequence similarities. Results We showed that radial distribution functions (RDFs, which are associated with the local structural and physicochemical properties of catalytic active sites, are capable of clustering oxidoreductases and transferases by function. The catalytic sites of these enzymes were also characterized using the RDFs. The RDFs provided a measure of the similarity among the catalytic sites, detecting conformational changes caused by mutation of catalytic residues. Furthermore, the RDFs reinforced the classification of enzyme functions based on conventional sequence and structural alignments. Conclusions Our results demonstrate that the application of RDFs provides advantages in the functional classification of enzymes by providing information about catalytic sites.

  9. Kinetic properties of a sex pheromone-degrading enzyme: the sensillar esterase of Antheraea polyphemus.

    OpenAIRE

    Vogt, R G; Riddiford, L M; Prestwich, G D

    1985-01-01

    Behavioral and electrophysiological evidence has suggested that sex pheromone is rapidly inactivated within the sensory hairs soon after initiation of the action-potential spike. We report the isolation and characterization of a sex-pheromone-degrading enzyme from the sensory hairs of the silkmoth Antheraea polyphemus. In the presence of this enzyme at physiological concentration, the pheromone [(6E,11Z)-hexadecadienyl acetate] has an estimated half-life of 15 msec. Our findings suggest a mol...

  10. Discriminative Stimulus Properties of the Endocannabinoid Catabolic Enzyme Inhibitor SA-57 in Mice

    OpenAIRE

    Owens, Robert A.; Ignatowska-Jankowska, Bogna; Mustafa, Mohammed; Beardsley, Patrick M.; Wiley, Jenny L.; Jali, Abdulmajeed; Selley, Dana E.; Niphakis, Micah J.; Cravatt, Benjamin F.; Lichtman, Aron H.

    2016-01-01

    Whereas the inhibition of fatty acid amide hydrolase (FAAH) or monoacylglycerol lipase (MAGL), the respective major hydrolytic enzymes of N-arachidonoyl ethanolamine (AEA) and 2-arachidonoylglycerol (2-AG), elicits no or partial substitution for Δ9-tetrahydrocannabinol (THC) in drug-discrimination procedures, combined inhibition of both enzymes fully substitutes for THC, as well as produces a constellation of cannabimimetic effects. The present study tested whether C57BL/6J mice would learn t...

  11. Novel Biocatalysts Combining the Special Assembly Properties of S-Layer Proteins and the Functionality of Enzymes of Extremophiles (BIOCAT)

    Science.gov (United States)

    2010-04-14

    recrystallization properties of rSbpA/LamAAs shown by transmission electron microscopy of negatively stained preparations. rSbpA/LamA had the capability...the restriction sites BamHl and Noll were introduced at the 5’ and 3’ ends, respectively. For expression, all recombinant plasm ids were established...Laccase oxidizes hydroquinone to quinone by releasing two protons and two electrons . In the presence of oxygen, the enzyme forms water. First of all the

  12. Selected essential oils inhibit key physiological enzymes and possess intracellular and extracellular antimelanogenic properties in vitro

    Directory of Open Access Journals (Sweden)

    Zaahira Aumeeruddy-Elalfi

    2018-01-01

    Full Text Available Essential oils (EOs extracted from six medicinal herbs and food plants [Cinnamomum zeylanicum (CZ, Psiadia arguta (PA, Psiadia terebinthina (PT, Citrus grandis (CGp, Citrus hystrix (CH, and Citrus reticulata (CR] were studied for any inhibitory potential against key physiological enzymes involved in diabetes (α-glucosidase, skin aging (collagenase and elastase, and neurodegenerative disorders (acetylcholinesterase. Kinetic studies of the active EOs on the aforementioned enzymes were determined using Lineweaver–Burk plots. The intracellular and extracellular antimelanogenic potential of the EOs were evaluated on B16F10 mouse melanocytes. CH and CR were found to significantly inhibit (2.476 ± 0.13 μg/mL and 3.636 ± 0.10 μg/mL, respectively acetylcholinesterase, compared with galantamine (3.989 ± 0.16 μg/mL. CH inhibited collagenase (50% inhibitory concentration 28.71 ± 0.16 μg/mL compared with the control (24.45 ± 0.19 μg/mL. The percentage inhibition in the elastase assay of CH was 63.21% compared to the positive control (75.09%. In addition, CH, CR, CGp, CZ, and PT were found to significantly inhibit α-glucosidase (276.70 ± 0.73 μg/mL, 169.90 ± 0.58 μg/mL, 240.60 ± 6.50 μg/mL, 64.52 ± 0.69 μg/mL, and 313.0 ± 5.0 μg/mL, respectively, compared to acarbose (448.80 ± 0.81 μg/mL. Active EOs showed both uncompetitive and competitive types of inhibition. The EOs also inhibited intracellular (50% inhibitory concentration 15.92 ± 1.06 μg/mL, 23.75 ± 4.47 μg/mL, and 28.99 ± 5.70 μg/mL for CH, CR, and CGp, respectively and extracellular (< 15.625 μg/mL for CH, CR, CGp, and PT melanin production when tested against B16F10 mouse melanocytes. Results from the present study tend to show that EOs extracted from these medicinal plants can inhibit key enzymes and may be potential candidates for cosmetic and pharmaceutical industries.

  13. Chilean berry Ugni molinae Turcz. fruit and leaves extracts with interesting antioxidant, antimicrobial and tyrosinase inhibitory properties.

    Science.gov (United States)

    López de Dicastillo, Carol; Bustos, Fernanda; Valenzuela, Ximena; López-Carballo, Gracia; Vilariño, Jose M; Galotto, Maria Jose

    2017-12-01

    The knowledge of the biological properties of fruits and leaves of murta (Ugni molinae Turcz.) has been owned by native Chilean culture. The present study investigated the phenolic content, the antioxidant, antimicrobial and anti-tyrosinase activities of different murta fruit and leaves extracts to approach their uses on future food, pharmaceutical and cosmetic applications. Extractions of murta fruit and leaves were carried out under water, ethanol and ethanol 50%. Phenolic content of these extracts was measured through Folin Ciocalteu test and the antioxidant power by four different antioxidant systems (ORAC, FRAP, DPPH and TEAC assays) owing to elucidate the main mechanism of antioxidant. Some flavonoids, such as rutin, isoquercitrin and quercitrin hydrate were identified and quantified through HPLC analysis. Antimicrobial activity was determined measuring minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) values against Escherichia coli and Listeria monocytogenes, and the effect of these extracts on L. monocytogenes was confirmed by flow cytometry. Highest contents of polyphenol compounds were obtained in hydroalcoholic extracts (28±1mggallicacid/g dry fruit, and 128±6mggallicacid/g dry leaves). The same trend was found for the values of biological properties: hydroalcoholic extracts showed the strongest activities. Leaves presented higher antioxidant, antimicrobial and anti-tyrosinase properties than murta fruit. Highest antioxidant activity values according to ORAC, FRAP, TEAC and DPPH were 80±8mgTrolox/g, 70±2mgTrolox/g, 87±8mgTrolox/g and 110±12mgTrolox/g, respectively, for murta fruit samples, and 280±10mgTrolox/g, 192±4mgTrolox/g, 286±13mgTrolox/g and 361±13mgTrolox/g, respectively, for murta leaves. These activities were confirmed by HPLC analysis that revealed highest presence of analyzed compounds on leaves hydroalcoholic extract. Regarding to antimicrobial analysis, hydroalcoholic leaves extract presented the

  14. Changes in wetting properties of silica surface treated with DPPC in the presence of phospholipase A{sub 2} enzyme

    Energy Technology Data Exchange (ETDEWEB)

    Wiacek, Agnieszka Ewa, E-mail: a.wiacek@poczta.umcs.lublin.pl [Department of Interfacial Phenomena, Faculty of Chemistry, Maria Curie-Sklodowska University, 20031 Lublin (Poland)

    2010-10-01

    Wetting properties of silica plates contacted with dipalmitoylphosphatidylcholine (DPPC) or DPPC/enzyme (phospholipase PLA{sub 2}) in NaCl solution were determined by thin layer wicking and with a help of Washburn equation. The wicking experiments were performed both for bare plates and the silica plates precontacted overnight with the probe liquid saturated vapors the silica plates, as well as untreated and DPPC (or DPPC/enzyme) treated. Adsorption of DPPC on original silica plates increases a bit hydrophobic character of silica surface in such a way that hydrocarbon chains are directed outwards and the polar part towards the silica surface. However, after the enzyme action the products of DPPC hydrolysis by PLA{sub 2} (palmitic acid and lysophosphatidylcholine) increase again hydrophilic character of silica surface (an increase in acid-base interactions, {gamma}{sub s}{sup AB}). The changes of silica surface wettability are evidently dependent on the time of enzyme contacting with DPPC in NaCl solution. Although, the changes of total surface free energy of silica after treatment with DPPC/enzyme solution are minor about 2-6 mJ/m{sup 2}, the changes of the electron-donor ({gamma}{sub s}{sup -}) and Lifshitz-van der Waals ({gamma}{sub s}{sup LW}) component of the surface free energy are noticeable. Despite, these results are somehow preliminary, it seems that thin layer wicking method is an interesting tool for investigation of the effect of adsorbed DPPC on hydrophobicity/hydrophilicity of silica surface and influence of enzyme PLA{sub 2} action.

  15. Mammalian folylpoly-γ-glutamate synthetase. 1. Purification and general properties of the hog liver enzyme

    International Nuclear Information System (INIS)

    Cichowicz, D.J.; Shane, B.

    1987-01-01

    Folylpolyglutamate synthetase was purified 30,000-150,000-fold from hog liver. Purification required the use of protease inhibitors, and the protein was purified to homogeneity in two forms. Both forms of the enzyme were monomers of M/sub r/ 62,000 and had similar specific activities. The specific activity of the homogeneous protein was over 2000-fold higher than reported for partially purified folylpolyglutamate synthetases from other mammalian sources. Enzyme activity was absolutely dependent on the presence of a reducing agent and a monovalent cation, of which K + was most effective. The purified enzyme catalyzed a MgATP-dependent addition of glutamate to tetrahydrofolate with the concomitant stoichiometric formation of MgADP and phosphate. Under conditions that resembled the expected substrate and enzyme concentrations in hog liver, tetrahydrofolate was metabolized to long glutamate chain length derivatives with the hexaglutamate, the major in vivo folate derivative, predominating. Enzyme activity was maximal at about pH 9.5. The high-pH optimum was primarily due to an increase in the K/sub m/ value for the L-glutamate substrate at lower pH values, and the reaction proceeded effectively at physiological pH provided high levels of glutamate were supplied

  16. Catalytic properties of immobilized tannase produced from Aspergillus aculeatus compared with the free enzyme

    Directory of Open Access Journals (Sweden)

    A. B El-Tanash

    2011-09-01

    Full Text Available Aspergillus aculeatus tannase was immobilized on several carriers by entrapment and covalent binding with cross - linking. Tannase immobilized on gelatin with cross - linking agent showed the highest activity and immobilization yield. The optimum pH of the immobilized enzyme was shifted to a more acidic range compared with the free enzyme (from pH 5.5 to pH 5.0. The optimum temperature of the reaction was determined to be 50ºC for the free enzyme and 60ºC for the immobilized form. The thermal stability, as well as stability over a wide range of pH, was significantly improved by the immobilization process. The calculated Km of the immobilized tannase (11.8 mg ml-1 is higher than that of the free tannase (6.5 mg ml-1, while Vmax of the immobilized enzyme (0.32 U (µg protein-1 is lower than that of the free tannase (2.7 U (µg protein-1. The immobilized enzyme was able to retain 84 % of the initial catalytic activity after 5.0 cycles.

  17. Purification and Properties of a Polyester Polyurethane-Degrading Enzyme from Comamonas acidovorans TB-35.

    Science.gov (United States)

    Akutsu, Y; Nakajima-Kambe, T; Nomura, N; Nakahara, T

    1998-01-01

    A polyester polyurethane (PUR)-degrading enzyme, PUR esterase, derived from Comamonas acidovorans TB-35, a bacterium that utilizes polyester PUR as the sole carbon source, was purified until it showed a single band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). This enzyme was bound to the cell surface and was extracted by addition of 0.2% N,N-bis(3-d-gluconamidopropyl)deoxycholamide (deoxy-BIGCHAP). The results of gel filtration and SDS-PAGE showed that the PUR esterase was a monomer with a molecular mass of about 62,000 Da. This enzyme, which is a kind of esterase, degraded solid polyester PUR, with diethylene glycol and adipic acid released as the degradation products. The optimum pH for this enzyme was 6.5, and the optimum temperature was 45 degrees C. PUR degradation by the PUR esterase was strongly inhibited by the addition of 0.04% deoxy-BIGCHAP. On the other hand, deoxy-BIGCHAP did not inhibit the activity when p-nitrophenyl acetate, a water-soluble compound, was used as a substrate. These observations indicated that this enzyme degrades PUR in a two-step reaction: hydrophobic adsorption to the PUR surface and hydrolysis of the ester bond of PUR.

  18. Facile synthesis of enzyme-embedded magnetic metal-organic frameworks as a reusable mimic multi-enzyme system: mimetic peroxidase properties and colorimetric sensor.

    Science.gov (United States)

    Hou, Chen; Wang, Yang; Ding, Qinghua; Jiang, Long; Li, Ming; Zhu, Weiwei; Pan, Duo; Zhu, Hao; Liu, Mingzhu

    2015-11-28

    This work reports a facile and easily-achieved approach for enzyme immobilization by embedding glucose oxidase (GOx) in magnetic zeolitic imidazolate framework 8 (mZIF-8) via a de novo approach. As a demonstration of the power of such materials, the resulting GOx embedded mZIF-8 (mZIF-8@GOx) was utilized as a colorimetric sensor for rapid detection of glucose. This method was constructed on the basis of metal-organic frameworks (MOFs), which possessed very fascinating peroxidase-like properties, and the cascade reaction for the visual detection of glucose was combined into one step through the mZIF-8@GOx based mimic multi-enzyme system. After characterization by electron microscopy, X-ray diffraction, nitrogen sorption, fourier transform infrared spectroscopy and vibrating sample magnetometry, the as-prepared mZIF-8@GOx was confirmed with the robust core-shell structure, the monodisperse nanoparticle had an average diameter of about 200 nm and displayed superparamagnetism with a saturation magnetization value of 40.5 emu g(-1), it also exhibited a large surface area of 396.10 m(2) g(-1). As a peroxidase mimic, mZIF-8 was verified to be highly stable and of low cost, and showed a strong affinity towards H2O2. Meanwhile, the mZIF-8 embedded GOx also exhibited improved activity, stability and greatly enhanced selectivity in glucose detection. Moreover, the mZIF-8@GOx had excellent recyclability with high activity (88.7% residual activity after 12 times reuse).

  19. Purification and Properties of a Polyester Polyurethane-Degrading Enzyme from Comamonas acidovorans TB-35

    OpenAIRE

    Akutsu, Yukie; Nakajima-Kambe, Toshiaki; Nomura, Nobuhiko; Nakahara, Tadaatsu

    1998-01-01

    A polyester polyurethane (PUR)-degrading enzyme, PUR esterase, derived from Comamonas acidovorans TB-35, a bacterium that utilizes polyester PUR as the sole carbon source, was purified until it showed a single band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). This enzyme was bound to the cell surface and was extracted by addition of 0.2% N,N-bis(3-d-gluconamidopropyl)deoxycholamide (deoxy-BIGCHAP). The results of gel filtration and SDS-PAGE showed that the PUR este...

  20. S-protected thiolated chitosan for oral delivery of hydrophilic macromolecules: evaluation of permeation enhancing and efflux pump inhibitory properties.

    Science.gov (United States)

    Dünnhaupt, Sarah; Barthelmes, Jan; Rahmat, Deni; Leithner, Katharina; Thurner, Clemens C; Friedl, Heike; Bernkop-Schnürch, Andreas

    2012-05-07

    The objective of this study was the investigation of permeation enhancing and P-glycoprotein (P-gp) inhibition effects of a novel thiolated chitosan, the so-named S-protected thiolated chitosan. Mediated by a carbodiimide, increasing amounts of thioglycolic acid (TGA) were covalently bound to chitosan (CS) in the first step of modification. In the second step, these thiol groups of thiolated chitosan were protected by disulfide bond formation with the thiolated aromatic residue 6-mercaptonicotinamide (6-MNA). Mucoadhesive properties of all conjugates were evaluated in vitro on porcine intestinal mucosa based on tensile strength investigations. Permeation enhancing effects were evaluated ex vivo using rat intestinal mucosa and in vitro via Caco-2 cells using the hydrophilic macromolecule FD(4) as the model drug. Caco-2 cells were further used to show P-gp inhibition effects by using Rho-123 as P-gp substrate. Apparent permeability coefficients (P(app)) were calculated and compared to values obtained from each buffer control. Three different thiolated chitosans were generated in the first step of modification, which displayed increasing amounts of covalently attached free thiol groups on the polymer backbone. In the second modification step, more than 50% of these free thiol groups were covalently linked with 6-MNA. Within 3 h of permeation studies on excised rat intestine, P(app) values of all S-protected chitosans were at least 1.3-fold higher compared to those of corresponding thiomers and more than twice as high as that of unmodified chitosan. Additional permeation studies on Caco-2 cells confirmed these results. Because of the chemical modification and higher amount of reactive thiol groups, all S-protected thiolated chitosans exhibit at least 1.4-fold pronounced P-gp inhibition effects in contrast to their corresponding thiomers. These features approve S-protected thiolated chitosan as a promising excipient for various drug delivery systems providing improved

  1. Design and Properties of an Immobilization Enzyme System for Inulin Conversion.

    Science.gov (United States)

    Hang, Hua; Wang, Changbao; Cheng, Yiqun; Li, Ning; Song, Liuli

    2018-02-01

    A commercial inulinase could convert inulin into fructose, which was optimized to be entrapped in the calcium alginate-gelatin beads with the immobilization yield of 86% for free inulinase activities. The optimum pH values and temperatures were 4.5 and 40 °C for the free enzyme and 5.0-5.5 and 45-50 °C for the immobilized enzyme. The kinetic parameters of V max and K m were 5.24 μmol/min and 57.6 mg/mL for the free inulinase and 4.32 μmol/min and 65.8 mg/mL for the immobilized inulinase, respectively. The immobilized enzyme retained 80% of its initial activities at 45 °C for 4 days, which could exhibit better thermal stability. The reuse of immobilized inulinase throughout the continuous batch operations was explored, which had better reusability of the immobilized biocatalyst. At the same time, the stability of immobilized enzyme in the continuous packed-bed bioreactor was estimated, which showed the better results and had its potential scale-up fructose production for inulin conversion.

  2. DNA-tension dependence of restriction enzyme activity reveals mechanochemical properties of the reaction pathway

    NARCIS (Netherlands)

    van den Broek, B.; Noom, M.C.; Wuite, G.J.L.

    2005-01-01

    Type II restriction endonucleases protect bacteria against phage infections by cleaving recognition sites on foreign double-stranded DNA (dsDNA) with extraordinary specificity. This capability arises primarily from large conformational changes in enzyme and/or DNA upon target sequence recognition.

  3. Structural Basis for Specificity of Propeptide-Enzyme Interaction in Barley C1A Cysteine Peptidases

    Science.gov (United States)

    Cambra, Inés; Hernández, David; Diaz, Isabel; Martinez, Manuel

    2012-01-01

    C1A cysteine peptidases are synthesized as inactive proenzymes. Activation takes place by proteolysis cleaving off the inhibitory propeptide. The inhibitory capacity of propeptides from barley cathepsin L and B-like peptidases towards commercial and barley cathepsins has been characterized. Differences in selectivity have been found for propeptides from L-cathepsins against their cognate and non cognate enzymes. Besides, the propeptide from barley cathepsin B was not able to inhibit bovine cathepsin B. Modelling of their three-dimensional structures suggests that most propeptide inhibitory properties can be explained from the interaction between the propeptide and the mature cathepsin structures. Their potential use as biotechnological tools is discussed. PMID:22615948

  4. Anti-Inflammatory and Antioxidant Properties of Casein Hydrolysate Produced Using High Hydrostatic Pressure Combined with Proteolytic Enzymes.

    Science.gov (United States)

    Bamdad, Fatemeh; Shin, Seulki Hazel; Suh, Joo-Won; Nimalaratne, Chamila; Sunwoo, Hoon

    2017-04-10

    Casein-derived peptides are shown to possess radical scavenging and metal chelating properties. The objective of this study was to evaluate novel anti-inflammatory properties of casein hydrolysates (CH) produced by an eco-friendly process that combines high hydrostatic pressure with enzymatic hydrolysis (HHP-EH). Casein was hydrolysed by different proteases, including flavourzyme (Fla), savinase (Sav), thermolysin (Ther), trypsin (Try), and elastase (Ela) at 0.1, 50, 100, and 200 MPa pressure levels under various enzyme-to-substrate ratios and incubation times. Casein hydrolysates were evaluated for the degree of hydrolysis (DH), molecular weight distribution patterns, and anti-inflammatory properties in chemical and cellular models. Hydrolysates produced using HHP-EH exhibited higher DH values and proportions of smaller peptides compared to atmospheric pressure-enzymatic hydrolysis (AP-EH). Among five enzymes, Fla-digested HHP-EH-CH (HHP-Fla-CH) showed significantly higher antioxidant properties than AP-Fla-CH. The anti-inflammatory properties of HHP-Fla-CH were also observed by significantly reduced nitric oxide and by the suppression of the synthesis of pro-inflammatory cytokines in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells. Liquid chromatography with tandem mass spectrometry (LC-MS/MS) revealed that 59% of the amino acids of the peptides in HHP-Fla-CH were composed of proline, valine, and leucine, indicating the potential anti-inflammatory properties. In conclusion, the HHP-EH method provides a promising technology to produce bioactive peptides from casein in an eco-friendly process.

  5. Enzyme oxidation of plant galactomannans yielding biomaterials with novel properties and applications, including as delivery systems.

    Science.gov (United States)

    Galante, Yves M; Merlini, Luca; Silvetti, Tiziana; Campia, Paola; Rossi, Bianca; Viani, Fiorenza; Brasca, Milena

    2018-06-01

    New biomaterials from renewable sources and the development of "functionalized biopolymers" are fields of growing industrial interest. Plant polysaccharides represent a valid alternative to traditional synthetic polymers, which are obtained from monomers of fossil, non-renewable origin. Several polysaccharides, either in their natural or chemically/biochemically modified forms, are currently employed in the biomedical, food and feed, and industrial fields, including packaging. Sustainable biochemical reactions, such as enzyme modifications of polysaccharides, open further possibilities for new product and process innovation. In the present review, we summarize the recent progress on enzyme oxidation of galactomannans (GM) from few leguminous plants (performed either with galactose oxidase or laccase) and we focus on the versatile and easily accessible laccase/TEMPO oxidative reaction. The latter causes a steep viscosity increase of GM water solutions and a transition of the gels from a viscous to an elastic form, due to formation of emiacetalic bonds and thus of internal cross-linking of the polymers. Following lyophilization of these hydrogels, stable aerogels can be obtained, which were shown to have good potential as delivery systems (DS) of actives. The active molecules tested and herewith described are polymyxin B, an antibiotic; nisin, an antimicrobial peptide; the enzymes lysozyme, protease and lipase; the mixture of the industrial microbiocides 5-chloro-2-methyl-4-isothiazolin-3-one (CIT) and 2-methyl-4-isothiazolin-3-one (MIT). The advantages of such aerogel systems and the possibilities they open for future developments, including as DS, are described.

  6. [Heidaigou Opencast Coal Mine: Soil Enzyme Activities and Soil Physical and Chemical Properties Under Different Vegetation Restoration].

    Science.gov (United States)

    Fang, Ying; Ma, Ren-tian; An, Shao-shan; Zhao, Jun-feng; Xiao, Li

    2016-03-15

    Choosing the soils under different vegetation recovery of Heidaigou dump as the research objects, we mainly analyzed their basic physical and chemical properties and enzyme activities with the method of Analysis of Variance as well as their relations using Pearson correlation analysis and path analysis hoping to uncover the driving factors of the differences between soil enzyme activities under different vegetation restoration, and provide scientific suggestions for the plant selection as well as make a better evaluation to the reclamation effect. The results showed that: (1) Although the artificial vegetation restoration improved the basic physical and chemical properties of the soils while increasing their enzyme activities to a certain extent, the soil conditions still did not reach the level of the natural grassland; (2) Contents of soil organic carbon (SOC) and soil total nitrogen (TN) of the seabuckthorns were the nearest to those of the grassland, which reached 54. 22% and 70. 00% of those of the grassland. In addition, the soil bulk density of the seabuckthorns stand was 17. 09% lower than the maximum value of the amorpha fruitcosa land. The SOC and TN contents as well as the bulk density showed that seabuckthorns had advantages as the species for land reclamation of this dump; Compared with the seabuckthorn, the pure poplar forest had lower contents of SOC and TN respectively by 35.64% and 32.14% and displayed a 16.79% higher value of soil bulk density; (3) The activities of alkaline phosphotase under different types of vegetation rehabilitation had little variation. But soil urease activities was more sensitive to reflect the effects of vegetation restoration on soil properties; (4) Elevation of the SOC and TN turned out to be the main cause for soil fertility restoration and increased biological activities of the dump.

  7. γ-Aminobutyric Acid (GABA) Production and Angiotensin-I Converting Enzyme (ACE) Inhibitory Activity of Fermented Soybean Containing Sea Tangle by the Co-Culture of Lactobacillus brevis with Aspergillus oryzae.

    Science.gov (United States)

    Jang, Eun Kyeong; Kim, Nam Yeun; Ahn, Hyung Jin; Ji, Geun Eog

    2015-08-01

    To enhance the γ-aminobutyric acid (GABA) content, the optimized fermentation of soybean with added sea tangle extract was evaluated at 30°C and pH 5.0. The medium was first inoculated with Aspergillus oryzae strain FMB S46471 and fermented for 3 days, followed by the subsequent inoculation with Lactobacillus brevis GABA 100. After fermentation for 7 days, the fermented soybean showed approximately 1.9 g/kg GABA and exhibited higher ACE inhibitory activity than the traditional soybean product. Furthermore, several peptides in the fraction containing the highest ACE inhibitory activity were identified. The novel fermented soybean enriched with GABA and ACE inhibitory components has great pharmaceutical and functional food values.

  8. Improvement of ACE inhibitory activity of casein hydrolysate by Maillard reaction with xylose.

    Science.gov (United States)

    Hong, Xu; Meng, Jun; Lu, Rong-Rong

    2015-01-01

    The Maillard reaction is widely used to improve the functional properties or biological activities of food. The purpose of this study was to investigate the effect of the Maillard reaction on angiotensin I converting enzyme (ACE) inhibitory activity in a casein hydrolysate-xylose system. Two-step hydrolysis was used to prepare casein ACE inhibitory peptides. Maillard reaction products (MRPs) were prepared by heating hydrolyzed casein with xylose at pH 8.0, 110 °C for up to 16 h. The results showed that the content of free amino group decreased (P Maillard reaction (P reaction in the MRPs. The study shows that the Maillard reaction under appropriate conditions can improve the ACE inhibitory activity of casein hydrolysate effectively. © 2014 Society of Chemical Industry.

  9. Plant nucleoside 5'-phosphoramidate hydrolase; simple purification from yellow lupin (Lupinus luteus) seeds and properties of homogeneous enzyme.

    Science.gov (United States)

    Guranowski, Andrzej; Wojdyła, Anna M; Rydzik, Anna M; Stepiński, Janusz; Jemielity, Jacek

    2011-01-01

    Adenosine 5'-phosphoramidate (NH₂-pA) is an uncommon natural nucleotide of poorly understood biochemistry and function. We studied a plant enzyme potentially involved in the catabolism of NH₂-pA. A fast and simple method comprising extraction of yellow lupin (Lupinus luteus) seed-meal with a low ionic strength buffer, ammonium sulfate and acetone fractionations, removal of contaminating proteins by heat denaturation, and affinity chromatography on AMP-agarose, yielded homogenous nucleoside 5'-phosphoramidase. Mass spectrometric analysis showed that the lupin hydrolase exhibits closest similarity to Arabidopsis thaliana Hint1 protein. The substrate specificity of the lupin enzyme, in particular its ability to split the P-S bond in adenosine 5'-phosphorothioate, is typical of known Hint1 proteins. Adenosine 5'-phosphofluoride and various derivatives of guanosine 5'-phosphoramidate were also substrates. Neither common divalent metal cations nor 10 mM EDTA or EGTA affected the hydrolysis of NH₂-pA. The enzyme functions as a homodimer (2 x 15,800 Da). At the optimum pH of 7.0, the K(m) for NH₂-pA was 0.5 µM and k(cat) 0.8 s⁻¹ (per monomer active site). The properties of the lupin nucleoside 5'-phosphoramidase are compared with those of its counterparts from other organisms.

  10. Effects of Heat Shock on Photosynthetic Properties, Antioxidant Enzyme Activity, and Downy Mildew of Cucumber (Cucumis sativus L..

    Directory of Open Access Journals (Sweden)

    Xiaotao Ding

    Full Text Available Heat shock is considered an abiotic stress for plant growth, but the effects of heat shock on physiological responses of cucumber plant leaves with and without downy mildew disease are still not clear. In this study, cucumber seedlings were exposed to heat shock in greenhouses, and the responses of photosynthetic properties, carbohydrate metabolism, antioxidant enzyme activity, osmolytes, and disease severity index of leaves with or without the downy mildew disease were measured. Results showed that heat shock significantly decreased the net photosynthetic rate, actual photochemical efficiency, photochemical quenching coefficient, and starch content. Heat shock caused an increase in the stomatal conductance, transpiration rate, antioxidant enzyme activities, total soluble sugar content, sucrose content, soluble protein content and proline content for both healthy leaves and downy mildew infected leaves. These results demonstrate that heat shock activated the transpiration pathway to protect the photosystem from damage due to excess energy in cucumber leaves. Potential resistance mechanisms of plants exposed to heat stress may involve higher osmotic regulation capacity related to an increase of total accumulations of soluble sugar, proline and soluble protein, as well as higher antioxidant enzymes activity in stressed leaves. Heat shock reduced downy mildew disease severity index by more than 50%, and clearly alleviated downy mildew development in the greenhouses. These findings indicate that cucumber may have a complex physiological change to resist short-term heat shock, and suppress the development of the downy mildew disease.

  11. Pathological manifestations in lymphatic filariasis correlate with lack of inhibitory properties of IgG4 antibodies on IgE-activated granulocytes.

    Science.gov (United States)

    Prodjinotho, Ulrich F; von Horn, Charlotte; Debrah, Alex Y; Batsa Debrah, Linda; Albers, Anna; Layland, Laura E; Hoerauf, Achim; Adjobimey, Tomabu

    2017-07-01

    Helminth parasites are known to be efficient modulators of their host's immune system. To guarantee their own survival, they induce alongside the classical Th2 a strong regulatory response with high levels of anti-inflammatory cytokines and elevated plasma levels of IgG4. This particular antibody was shown in different models to exhibit immunosuppressive properties. How IgG4 affects the etiopathology of lymphatic filariasis (LF) is however not well characterized. Here we investigate the impact of plasma and affinity-purified IgG/IgG4 fractions from endemic normals (EN) and LF infected pathology patients (CP), asymptomatic microfilaraemic (Mf+) and amicrofilaraemic (Mf-) individuals on IgE/IL3 activated granulocytes. The activation and degranulation states were investigated by monitoring the expression of CD63/HLADR and the release of granule contents (neutrophil elastase (NE), eosinophil cationic protein (ECP) and histamine) respectively by flow cytometry and ELISA. We could show that the activation of granulocytes was inhibited in the presence of plasma from EN and Mf+ individuals whereas those of Mf- and CP presented no effect. This inhibitory capacity was impaired upon depletion of IgG in Mf+ individuals but persisted in IgG-depleted plasma from EN, where it strongly correlated with the expression of IgA. In addition, IgA-depleted fractions failed to suppress granulocyte activation. Strikingly, affinity-purified IgG4 antibodies from EN, Mf+ and Mf- individuals bound granulocytes and inhibited activation and the release of ECP, NE and histamine. In contrast, IgG4 from CP could not bind granulocytes and presented no suppressive capacity. Reduction of both the affinity to, and the suppressive properties of anti-inflammatory IgG4 on granulocytes was reached only when FcγRI and II were blocked simultaneously. These data indicate that IgG4 antibodies from Mf+, Mf- and EN, in contrast to those of CP, natively exhibit FcγRI/II-dependent suppressive properties on

  12. Inference of functional properties from large-scale analysis of enzyme superfamilies.

    Science.gov (United States)

    Brown, Shoshana D; Babbitt, Patricia C

    2012-01-02

    As increasingly large amounts of data from genome and other sequencing projects become available, new approaches are needed to determine the functions of the proteins these genes encode. We show how large-scale computational analysis can help to address this challenge by linking functional information to sequence and structural similarities using protein similarity networks. Network analyses using three functionally diverse enzyme superfamilies illustrate the use of these approaches for facile updating and comparison of available structures for a large superfamily, for creation of functional hypotheses for metagenomic sequences, and to summarize the limits of our functional knowledge about even well studied superfamilies.

  13. Inference of Functional Properties from Large-scale Analysis of Enzyme Superfamilies*

    Science.gov (United States)

    Brown, Shoshana D.; Babbitt, Patricia C.

    2012-01-01

    As increasingly large amounts of data from genome and other sequencing projects become available, new approaches are needed to determine the functions of the proteins these genes encode. We show how large-scale computational analysis can help to address this challenge by linking functional information to sequence and structural similarities using protein similarity networks. Network analyses using three functionally diverse enzyme superfamilies illustrate the use of these approaches for facile updating and comparison of available structures for a large superfamily, for creation of functional hypotheses for metagenomic sequences, and to summarize the limits of our functional knowledge about even well studied superfamilies. PMID:22069325

  14. The persistent inhibitory properties of saxagliptin on renal dipeptidyl peptidase-4: Studies with HK-2 cells in vitro and normal rats in vivo

    Directory of Open Access Journals (Sweden)

    Masako Uchii

    2017-11-01

    Full Text Available Saxagliptin, a potent and selective DPP-4 inhibitor, exhibits a slow dissociation from DPP-4. We investigated the sustained effects of saxagliptin on renal DPP-4 activity in a washout study using renal tubular (HK-2 cells, and in a pharmacodynamic study using normal rats. In HK-2 cells, the inhibitory potency of saxagliptin on DPP-4 activity persisted after washout, while that of sitagliptin was clearly reduced. In normal rats, a single treatment of saxagliptin or sitagliptin inhibited the plasma DPP-4 activity to similar levels. The inhibitory action of saxagliptin on the renal DPP-4 activity was retained, even when its inhibitory effect on the plasma DPP-4 activity disappeared. However, the inhibitory action of sitagliptin on the renal DPP-4 activity was abolished in correlation with the inhibition of the plasma DPP-4 activity. In situ staining showed that saxagliptin suppressed the DPP-4 activity in both glomerular and tubular cells and its inhibitory effects were significantly higher than those of sitagliptin. Saxagliptin exerted a sustained inhibitory effect on the renal DPP-4 activity in vitro and in vivo. The long binding action of saxagliptin in renal tubular cells might involve the sustained inhibition of renal DPP-4.

  15. Virtual Dual inhibition of COX-2 / 5-LOX enzymes based on binding properties of alpha-amyrins, the anti-inflammatory compound as a promising anti-cancer drug

    Science.gov (United States)

    Ranjbar, Mohammad Mehdi; Assadolahi, Vahideh; Yazdani, Mohsen; Nikaein, Donya; Rashidieh, Behnam

    2016-01-01

    Hydro-alcoholic fruit extract of Cordia myxa was considerably effective on curing acute inflammation in mouse model. Previous studies suggested significant anti-inflammatory activities as well as potential anticancer agent of α-amyrins in seeds. Inhibition of Cyclooxygenase-2 (COX-2) and 5-Lipooxygenase (5-LOX) is significant in cancer prevention and therapeutics although this inhibition with chemo-drugs has its own side-effects. It is shown that these enzymes pathways are related to several cancers including colon, breast and lung cancer. This study was conducted based on Cordia species' α-amyrins as a safer natural anti-cancer compound for inhibition of COX-2 and 5-LOX enzymes by molecular docking. The X-ray crystal structure of COX2 / 5-LOX enzymes and α-amyrins was retrieved and energetically minimized respectively. The binding site and surface of enzymes were detected. Docking studies were performed by AutoDock 4.2 using Lamarckian genetic algorithm (LGA). Finally drug likeness, molecular pharmacokinetic properties and toxicity of α-amyrins was calculated. Molecular Docking revealed hydrogen and hydrophobic interactions between α-amyrins with both active sites of COX-2 and 5-LOX enzymes. Interestingly, it covalently bonded to Fe cofactor of 5-LOX enzyme and chelated this molecule. Base on binding energies (∆G) α-amyrin has more inhibitory effects on 5-LOX (-10.45 Kcal/mol) than COX-2 (-8.02 Kcal/mol). Analysis of molecular pharmacokinetic parameters suggested that α-amyrins complied with most sets of Lipinski's rules, and so it could be a suitable ligand for docking studies. Eventually, bioactivity score showed α-amyrins possess considerable biological activities as nuclear receptor, enzyme inhibitor, GPCR and protease inhibitor ligand. These results clearly demonstrate that α-amyrins could act as potential highly selective COX-/5-LOX inhibitor. Also, it is a safe compound in comparison with classical non-steroidal anti-inflammatory drugs (NSAIDs

  16. Phosphoenolpyruvate-dependent protein kinase enzyme I of Streptococcus faecalis: purification and properties of the enzyme and characterization of its active center

    International Nuclear Information System (INIS)

    Alpert, C.A.; Frank, R.; Stueber, K.D.; Deutscher, J.; Hengstenberg, W.

    1985-01-01

    Enzyme I, the phosphoenolpyruvate:protein phosphotransferase (EC 2.7.3.9), which is part of the bacterial phosphoenolpyruvate-(PEP) dependent phosphotransferase system, has been purified from Streptococcus faecalis by using a large-scale preparation. Size exclusion chromatography revealed a molecular weight of 140,000. On sodium dodecyl sulfate gels, enzyme I gave one band with a molecular weight of 70,000, indicating that enzyme I consists of two identical subunits. The first 59 amino acids of the amino-terminal part of the protein have been sequenced. It showed some similarities with enzyme I of Salmonella typhimurium. The active center of enzyme I has also been determined. After phosphorylation with [ 32 P]PEP, the enzyme was cleaved by using different proteases. Labeled peptides were isolated by high-performance liquid chromatography on a reversed-phase column. The amino acid composition or amino acid sequence of the peptides has been determined. The largest labeled peptide was obtained with Lys-C protease and had the following sequence: -Ala-Phe-Val-Thr-Asp-Ile-Gly- Gly-Arg-Thr-Ser-His*-Ser-Ala-Ile-Met-Ala-Arg-Ser-Leu-Glu-Ile-Pro-Ala- Ile-Val-Gly-Thr-Lys-. It has previously been shown that the phosphoryl group is bound to the N-3 position of a histidyl residue in phosphorylated enzyme I. The single His in position 12 of the above peptide must therefore carry the phosphoryl group

  17. [Substrate-inhibitory analysis of monoamine oxidase from hepatopancreas of the octopus Bathypolypus arcticus].

    Science.gov (United States)

    Basova, I N; Iagodina, O V

    2012-01-01

    Study of the substrate-inhibitory specificity of mitochondrial monoamine oxidase (MAO) of hepatopancreas of the octopus Bathypolypus arcticus revealed distinctive peculiarities of catalytic properties of this enzyme. The studied enzyme, on one hand, like the classic MAO of homoiothermal animals, is able to deaminate tyramine, serotonin, benzylamine, tryptamine, beta-phenylethylamine, while, on the other hand, deaminates histamine and does not deaminate putrescine--classic substrates of diamine oxidase (DAO). Results of the substrate-inhibitory analysis with use of chlorgiline and deprenyl are indirect proofs of the existence in the octopus hepatopancreas of one molecular MAO form. Semicarbazide and pyronine G turned out to be weak irreversible inhibitors, four derivatives of acridine--irreversible inhibitors of the intermediate effectiveness with respect to the octopus hepatopancreas MAO; specificity of action of inhibitors at deamination of different substrates was equal.

  18. Sempervivum davisii: phytochemical composition, antioxidant and lipase-inhibitory activities.

    Science.gov (United States)

    Uzun, Yusuf; Dalar, Abdullah; Konczak, Izabela

    2017-12-01

    Sempervivum davisii Muirhead (Crassulaceae) is a traditional medicinal herb from Eastern Anatolia. To date the composition of phytochemicals and physiological properties of this herb were not subjected to any research. This study identifies compounds in S. davisii hydrophilic extracts and evaluates their potential biological properties. Ethanol-based lyophilized extracts were obtained from aerial parts of plant (10 g of ground dry plant material in 200 mL of acidified aqueous ethanol, shaken for 2 h at 22 °C with supernatant collected and freeze-dried under vacuum). Phytochemical composition was investigated by liquid chromatography mass spectrometry (LC-MS/MS, phenolics) and gas chromatography mass spectrometry (GC-MS, volatiles). Phenolic compounds were quantified by high-performance liquid chromatography (HPLC) and the Folin-Ciocalteu assay. Subsequently, antioxidant capacity [ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC) assays] and enzyme inhibitory properties (isolated porcine pancreatic lipase) of the extracts were determined. Polyphenolic compounds were the main constituents of lyophilized extracts, among which kaempferol glycosides and quercetin hexoside dominated. The extracts exhibited potent antioxidant (FRAP values of 1925.2-5973.3 μM Fe 2+ /g DW; ORAC values of 1858.5-4208.7 μM Trolox Eq./g DW) and moderate lipase inhibitory (IC 50 : 11.6-2.96 mg/mL) activities. Volatile compounds (nonanal, dehydroxylinalool oxide isomers, 2-decenal, 2-undecenal, 2,6-di-tetr-butylphenol) were also found. Phenolic compounds with the dominating kaempferol and quercetin derivatives are the sources of potent antioxidant properties of S. davisii hydrophilic extracts. The extracts exhibit moderate inhibitory properties towards isolated pancreatic lipase.

  19. Inorganic pyrophosphatase in uncultivable hemotrophic mycoplasmas: identification and properties of the enzyme from Mycoplasma suis

    Directory of Open Access Journals (Sweden)

    Wittenbrink Max M

    2010-07-01

    Full Text Available Abstract Background Mycoplasma suis belongs to a group of highly specialized hemotrophic bacteria that attach to the surface of host erythrocytes. Hemotrophic mycoplasmas are uncultivable and the genomes are not sequenced so far. Therefore, there is a need for the clarification of essential metabolic pathways which could be crucial barriers for the establishment of an in vitro cultivation system for these veterinary significant bacteria. Inorganic pyrophosphatases (PPase are important enzymes that catalyze the hydrolysis of inorganic pyrophosphate PPi to inorganic phosphate Pi. PPases are essential and ubiquitous metal-dependent enzymes providing a thermodynamic pull for many biosynthetic reactions. Here, we describe the identification, recombinant production and characterization of the soluble (sPPase of Mycoplasma suis. Results Screening of genomic M. suis libraries was used to identify a gene encoding the M. suis inorganic pyrophosphatase (sPPase. The M. suis sPPase consists of 164 amino acids with a molecular mass of 20 kDa. The highest identity of 63.7% was found to the M. penetrans sPPase. The typical 13 active site residues as well as the cation binding signature could be also identified in the M. suis sPPase. The activity of the M. suis enzyme was strongly dependent on Mg2+ and significantly lower in the presence of Mn2+ and Zn2+. Addition of Ca2+ and EDTA inhibited the M. suis sPPase activity. These characteristics confirmed the affiliation of the M. suis PPase to family I soluble PPases. The highest activity was determined at pH 9.0. In M. suis the sPPase builds tetramers of 80 kDa which were detected by convalescent sera from experimentally M. suis infected pigs. Conclusion The identification and characterization of the sPPase of M. suis is an additional step towards the clarification of the metabolism of hemotrophic mycoplasmas and, thus, important for the establishment of an in vitro cultivation system. As an antigenic and conserved

  20. Synthesis, crystal structures, fluorescence and xanthine oxidase inhibitory activity of pyrazole-based 1,3,4-oxadiazole derivatives

    Science.gov (United States)

    Qi, De-Qiang; Yu, Chuan-Ming; You, Jin-Zong; Yang, Guang-Hui; Wang, Xue-Jie; Zhang, Yi-Ping

    2015-11-01

    A series of pyrazole-based 1,3,4-oxadiazole derivatives were rationally designed and synthesized in good yields by following a convenient route. All the newly synthesized molecules were fully characterized by IR, 1H NMR and elemental analysis. Eight compounds were structurally determined by single crystal X-ray diffraction analysis. The fluorescence properties of all the compounds were investigated in dimethyl sulfoxide media. In addition, these newly synthesized compounds were evaluated for in vitro inhibitory activity against commercial enzyme xanthine oxidase (XO) by measuring the formation of uric acid from xanthine. Among the compounds synthesized and tested, 3d and 3e were found to be moderate inhibitory activity against commercial XO with IC50 = 72.4 μM and 75.6 μM. The studies gave a new insight in further optimization of pyrazole-based 1,3,4-oxadiazole derivatives with excellent fluorescence properties and XO inhibitory activity.

  1. Antitumor properties and modulation of antioxidant enzymes' activity by Aloe vera leaf active principles isolated via supercritical carbon dioxide extraction.

    Science.gov (United States)

    El-Shemy, H A; Aboul-Soud, M A M; Nassr-Allah, A A; Aboul-Enein, K M; Kabash, A; Yagi, A

    2010-01-01

    The aim of this study was to evaluate the potential anticancer properties and modulatory effect of selected Aloe vera (A. vera) active principles on antioxidant enzyme activities. Thus, three anthraquinones (Namely: aloesin, aloe-emodin and barbaloin) were extracted from A. vera leaves by supercritical fluid extraction and subsequently purified by high performance liquid chromatography. Additionally, the N-terminal octapeptide derived from verectin, a biologically active 14 kDa glycoprotein present in A. vera, was also tested. In vivo, active principles exhibited significant prolongation of the life span of tumor-transplanted animals in the following order: barbaloin> octapeptide> aloesin > aloe-emodin. A. vera active principles exhibited significant inhibition on Ehrlich ascite carcinoma cell (EACC) number, when compared to positive control group, in the following order: barbaloin> aloe-emodin > octapeptide > aloesin. Moreover, in trypan blue cell viability assay, active principles showed a significant concentration-dependent cytotoxicity against acute myeloid leukemia (AML) and acute lymphocytes leukemia (ALL) cancerous cells. Furthermore, in MTT cell viability test, aloe-emodin was found to be active against two human colon cancer cell lines (i.e. DLD-1 and HT2), with IC(50) values of 8.94 and 10.78 microM, respectively. Treatments of human AML leukemic cells with active principles (100 microg ml(-1)) resulted in varying intensities of internucleosomal DNA fragmentation, hallmark of cells undergoing apoptosis, in the following order: aloe-emodin> aloesin> barbaloin> octapeptide. Intererstingly, treatment of EACC tumors with active principles resulted in a significant elevation activity of key antioxidant enzymes (SOD, GST, tGPx, and LDH). Our data suggest that the tested A. vera compounds may exert their chemo-preventive effect through modulating antioxidant and detoxification enzyme activity levels, as they are one of the indicators of tumorigenesis. These

  2. Catalytic Properties of Amylolytic Enzymes Produced by Gongronella butleri Using Agroindustrial Residues on Solid-State Fermentation

    Science.gov (United States)

    Cavalheiro, Gabriéla Finoto; Sanguine, Isadora Stranieri; Santos, Flávia Regina da Silva; da Costa, Ana Carolina; Fernandes, Matheus; da Paz, Marcelo Fossa; Fonseca, Gustavo Graciano

    2017-01-01

    Amylases catalyze the hydrolysis of starch, a vegetable polysaccharide abundant in nature. These enzymes can be utilized in the production of syrups, alcohol, detergent, pharmaceutical products, and animal feed formulations. The aim of this study was to optimize the production of amylases by the filamentous fungus Gongronella butleri by solid-state fermentation and to evaluate the catalytic properties of the obtained enzymatic extract. The highest amylase production, 63.25 U g−1 (or 6.32 U mL−1), was obtained by culturing the fungus in wheat bran with 55% of initial moisture, cultivated for 96 h at 25°C. The enzyme presented optimum activity at pH 5.0 and 55°C. The amylase produced was stable in a wide pH range (3.5–9.5) and maintained its catalytic activity for 1 h at 40°C. Furthermore, the enzymatic extract hydrolyzed starches from different vegetable sources, presenting predominant dextrinizing activity for all substrates evaluated. However, the presence of glucose was observed in a higher concentration during hydrolysis of corn starch, indicating the synergistic action of endo- and exoamylases, which enables the application of this enzymatic extract to produce syrups from different starch sources. PMID:29376074

  3. PHYSICOCHEMICAL PROPERTIES OF THE PROTEOLYTIC ENZYME FROM THE LATEX OF THE MILKWEED, ASCLEPIAS SPECIOSA TORR. SOME COMPARISONS WITH OTHER PROTEASES

    Science.gov (United States)

    Winnick, Theodore; Davis, Alva R.; Greenberg, David M.

    1940-01-01

    1. A study has been made of the properties of a hitherto unreported proteolytic enzyme from the latex of the milkweed, Asclepias speciosa. The new protease has been named asclepain by the authors. 2. The results of chemical, diffusion, and denaturation tests indicate that asclepain is a protein. 3. Like papain, asclepain dots milk and digests most proteins, particularly if they are dissolved in concentrated urea solution. Unlike papain, asclepain did not clot blood. 4. The activation and inhibition phenomena of asclepain resemble those of papain, and seem best explained on the assumption that free sulfhydryl in the enzyme is necessary for proteolytic activity. The sulfhydryl of asclepain appears more labile than that of papain. 5. The measurement of pH-activity curves of asclepain on casein, ovalbumin, hemoglobin, edestin, and ovovitellin showed no definite digestion maxima for most of the undenatured proteins, while in urea solution there were well defined maxima near pH 7.0. Native hemoglobin and ovovitellin were especially undigestible, while native casein was rapidly attacked. 6. Temperature-activity curves were determined for asclepain on hemoglobin, casein, and milk solutions. The optimum temperature was shown to increase with decreasing time of digestion. PMID:19873154

  4. Catalytic Properties of Amylolytic Enzymes Produced by Gongronella butleri Using Agroindustrial Residues on Solid-State Fermentation

    Directory of Open Access Journals (Sweden)

    Gabriéla Finoto Cavalheiro

    2017-01-01

    Full Text Available Amylases catalyze the hydrolysis of starch, a vegetable polysaccharide abundant in nature. These enzymes can be utilized in the production of syrups, alcohol, detergent, pharmaceutical products, and animal feed formulations. The aim of this study was to optimize the production of amylases by the filamentous fungus Gongronella butleri by solid-state fermentation and to evaluate the catalytic properties of the obtained enzymatic extract. The highest amylase production, 63.25 U g−1 (or 6.32 U mL−1, was obtained by culturing the fungus in wheat bran with 55% of initial moisture, cultivated for 96 h at 25°C. The enzyme presented optimum activity at pH 5.0 and 55°C. The amylase produced was stable in a wide pH range (3.5–9.5 and maintained its catalytic activity for 1 h at 40°C. Furthermore, the enzymatic extract hydrolyzed starches from different vegetable sources, presenting predominant dextrinizing activity for all substrates evaluated. However, the presence of glucose was observed in a higher concentration during hydrolysis of corn starch, indicating the synergistic action of endo- and exoamylases, which enables the application of this enzymatic extract to produce syrups from different starch sources.

  5. Purification of PON1 from human serum and assessment of enzyme kinetics against metal toxicity.

    Science.gov (United States)

    Ekinci, Deniz; Beydemir, Sükrü

    2010-06-01

    Paraoxonase-1 (PON1) is an organophosphate hydrolyser enzyme which has also antioxidant properties in metabolism. Due to its crucial functions, inhibition of the enzyme is undesirable and very dangerous. PON1 enzyme activity should not be altered in any case. Inhibitory investigations of this enzyme are therefore important and useful. Metal toxicology of enzymes has become popular in the recent years. Here, we report the in vitro inhibitory effects of some metal ions, including Pb(+2), Cr(+2), Fe(+2), and Zn(+2), on the activity of human serum PON1 (hPON1; EC 3.1.8.1.). For this purpose, we purified the enzyme from human serum and analyzed the alterations in the enzyme activity in the presence of metal ions. The results show that metal ions exhibit inhibitory effects on hPON1 at low concentrations with IC (50) values ranging from 0.838 to 7.410 mM. Metal ions showed different inhibition mechanisms: lead and iron were competitive, chrome was noncompetitive, and zinc was uncompetitive. Lead was determined to be the most effective inhibitor.

  6. Pressure stabilization is not a general property of thermophilic enzymes: the adenylate kinases of Methanococcus voltae, Methanococcus maripaludis, Methanococcus thermolithotrophicus, and Methanococcus jannaschii.

    OpenAIRE

    Konisky, J; Michels, P C; Clark, D S

    1995-01-01

    The application of 50-MPa pressure did not increase the thermostabilities of adenylate kinases purified from four related mesophilic and thermophilic marine methanogens. Thus, while it has been reported that some thermophilic enzymes are stabilized by pressure (D. J. Hei and D. S. Clark, Appl. Environ. Microbiol. 60:932-939, 1994), hyperbaric stabilization is not an intrinsic property of all enzymes from deep-sea thermophiles.

  7. Toward "stable-on-the-table" enzymes: improving key properties of catalase by covalent conjugation with poly(acrylic acid).

    Science.gov (United States)

    Riccardi, Caterina M; Cole, Kyle S; Benson, Kyle R; Ward, Jessamyn R; Bassett, Kayla M; Zhang, Yiren; Zore, Omkar V; Stromer, Bobbi; Kasi, Rajeswari M; Kumar, Challa V

    2014-08-20

    Several key properties of catalase such as thermal stability, resistance to protease degradation, and resistance to ascorbate inhibition were improved, while retaining its structure and activity, by conjugation to poly(acrylic acid) (PAA, Mw 8000) via carbodiimide chemistry where the amine groups on the protein are appended to the carboxyl groups of the polymer. Catalase conjugation was examined at three different pH values (pH 5.0, 6.0, and 7.0) and at three distinct mole ratios (1:100, 1:500, and 1:1000) of catalase to PAA at each reaction pH. The corresponding products are labeled as Cat-PAA(x)-y, where x is the protein to polymer mole ratio and y is the pH used for the synthesis. The coupling reaction consumed about 60-70% of the primary amines on the catalase; all samples were completely water-soluble and formed nanogels, as evidenced by gel electrophoresis and electron microscopy. The UV circular dichroism (CD) spectra indicated substantial retention of protein secondary structure for all samples, which increased to 100% with increasing pH of the synthesis and polymer mole fraction. Soret CD bands of all samples indicated loss of ∼50% of band intensities, independent of the reaction pH. Catalytic activities of the conjugates increased with increasing synthesis pH, where 55-80% and 90-100% activity was retained for all samples synthesized at pH 5.0 and pH 7.0, respectively, and the Km or Vmax values of Cat-PAA(100)-7 did not differ significantly from those of the free enzyme. All conjugates synthesized at pH 7.0 were thermally stable even when heated to ∼85-90 °C, while native catalase denatured between 55 and 65 °C. All conjugates retained 40-90% of their original activities even after storing for 10 weeks at 8 °C, while unmodified catalase lost all of its activity within 2 weeks, under similar storage conditions. Interestingly, PAA surrounding catalase limited access to the enzyme from large molecules like proteases and significantly increased

  8. [Angiotensin converting enzyme: the antigenic properties of the domain, role in Alzheimer's disease and tumor progression].

    Science.gov (United States)

    Kugaevskaya, E V; Timoshenko, O S; Solovyeva, N I

    2015-01-01

    Angiotensin converting enzyme (ACE, EC 3.4.15.1) was discovered and characterized in the Laboratory of biochemistry and chemical pathology of proteins under the direction of academician V.N. Orekhovich, where its physiological function, associated with a key role in the regulation of the renin-angiotensin (RAS) and the kallikrein-kinin systems that control blood flow in the body and homeostasis was first deciphered. We carried out a search for structural differences between the two highly homologous domains (N- and C-domains) of somatic ACE (sACE); it was based on a comparative analysis of antigenic determinants (or B-epitopes) of both domains. The revealed epitopes were classified with variable and conserved regions and functionally important sites of the molecule ACE. Essential difference was demonstrated between locations of the epitopes in the N- and C-domains. These data indicate the existence of structural differences between the domains of sACE. We studied the role of the domains of ACE in the metabolism of human amyloid beta peptide (Ab) - the main component of senile plaques, found in the brains of patients with Alzheimer's disease (AD). Our results demonstrated that only N-domain ACE cleaved the Ab between residues R5-H6, while, the C-domain of ACE failed to hydrolyze this region. In addition, the effect of post-translational modifications of Ab on its hydrolysis by the ACE was investigated. We show that isomerization of residue D7, a common non-enzymatic age-related modification found in AD-associated species, does not reduce the affinity of the peptide to the N-domain of ACE, and conversely, it increases. According to our data, the role of ACE in the metabolism of Ab becomes more significant in the development of AD. RAS is involved in malignant transformation and tumor progression. RAS components, including ACE and angiotensin II receptors type 1 (AT1R) are expressed in various human tumors. We found a significant increase in the level of ACE activity

  9. Nutritional, amylolytic enzymes inhibition and antioxidant properties of bread incorporated with Stevia rebaudiana.

    Science.gov (United States)

    Ruiz-Ruiz, Jorge C; Moguel-Ordoñez, Yolanda B; Matus-Basto, Angel J; Segura-Campos, Maira R

    2015-01-01

    Wheat bread with sucrose content replaced with different levels of stevia extract was compared with traditional wheat bread. The ability to reduce glucose intake was highlighted by performing enzymatic assays using α-amylase and α-glucosidase. Antioxidant activity was measured by determining the scavenging effect on α,α-diphenyl-β-picrylhydrazyl radical. In comparison with the control, the bread with stevia extract was softer and had lower microbial growth during the shelf-life study. The sensory test showed that the substitution of 50% stevia extract was more acceptable when comparing with all the quality characteristics. Regarding the nutritional contribution, the content of dietary fiber and digestible carbohydrates in the bread with stevia extract was higher and lower respectively, so caloric intake was significantly reduced. The results showed that the biological properties of Stevia rebaudiana extract were retained after the bread making process and that the proposed bread could be suitable as functional food in human nutrition.

  10. Fruit Wines Inhibitory Activity Against α-Glucosidase.

    Science.gov (United States)

    Cakar, Uros; Grozdanic, Nada; Petrovic, Aleksandar; Pejin, Boris; Nastasijevic, Branislav; Markovic, Bojan; Dordevic, Brizita

    2017-01-01

    Fruit wines are well known for their profound health-promoting properties including both enzyme activations and inhibitions. They may act preventive in regard to diabetes melitus and other chronic diseases. Potential α-glucosidase inhibitory activity of fruit wines made from blueberry, black chokeberry, blackberry, raspberry and sour cherry was the subject of this study. In order to increase the alcohol content due to enriched extraction of total phenolics, sugar was added in the fruit pomace of the half of the examined fruit wine samples. Compared with acarbose used as a positive control (IC50 = 73.78 µg/mL), all fruit wine samples exhibited higher α-glucosidase inhibitory activity. Indeed, blueberry wine samples stood out, both prepared with IC50 = 24.14 µg/mL, lyophilised extract yield 3.23% and without IC50 = 46.39 µg/mL, lyophilised extract yield 2.89% and with addition of sugar before fermentation. Chlorogenic acid predominantly contributed to α-glucosidase inhibitory activity of the blueberry, black chokeberry and sour cherry wine samples. However, ellagic acid, a potent α-glucosidase inhibitor possessing a planar structure, only slightly affected the activity of the blueberry wine samples, due to the lower concentration. In addition to this, molecular docking study of chlorogenic acid pointed out the importance of binding energy (-8.5 kcal/mol) for the inhibition of the enzyme. In summary, fruit wines made from blueberry should be primarily taken into consideration as a medicinal food targeting diabetes mellitus type 2 in the early stage, if additional studies would confirm their therapeutic potential for the control of postprandial hyperglycemia. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  11. In vitro tissue-digesting properties of krill enzymes compared with fibrinolysin/DNAse, papain and placebo

    NARCIS (Netherlands)

    Mekkes, J. R.; Le Poole, I. C.; Das, P. K.; Kammeyer, A.; Westerhof, W.

    1997-01-01

    Wound debridement, the removal of necrotic tissue, can be achieved with proteolytic enzymes. Recently, a new multi-enzyme preparation, krill enzyme, isolated from Antarctic shrimp-like organisms (Euphausia superba), was reported to possess powerful proteolytic activity towards protein substrates. In

  12. Inhibition of raw starch digestion by one glucoamylase preparation from black Aspergillus at high enzyme concentration

    Energy Technology Data Exchange (ETDEWEB)

    Saka, B C; Veda, S

    1981-09-01

    Raw starch digestion by glucoamylase I (Ab. G-I) preparation from black Aspergillus was inhibited significantly at relatively high concentration of the enzyme. The properties of this enzyme were studied together with those of another glucoamylase I (Nor. G-I), also from black Aspergillus. The two glucoamylases do not differ so much in their physico-chemical properties such as molecular weight, pH and thermal stability, pH and temperature optimum, substrate specificity, debranching activity, isoelectric point etc. The adsorption rate of both enzymes on raw starch increased by the increase of enzyme concentration. The raw starch digestion rate by adsorbed Ab. G-I, however, was decreased with the increase of concentration of enzyme whereas the same was increased in case of Nor. G-I. The inhibitory effect was weaker at 60 deg. Celcius or above. (Refs. 11).

  13. Antioxidant and Cholesterol Esterase Inhibitory Properties of Supplementation with Coconut Water in Submerged Cultivation of the Medicinal Chinese Caterpillar Mushroom, Ophiocordyceps sinensis CS1197 (Ascomycetes).

    Science.gov (United States)

    Shashidhar, G M; Kumar, S Sravan; Giridhar, P; Manohar, B

    2017-01-01

    We investigated the potential use of coconut water to supplement potato dextrose broth (PDB) in the production of Ophiocordyceps sinensis CS1197 by submerged cultivation. The basal PDB medium was modified by supplementation with tender coconut water (TCW) and mature coconut water (MCW) at 10% and 5% (v/v), respectively; these mixtures were cultured at 28°C for 14 days, with a pH of 7 and an inoculum volume of 10%. The addition of optimized levels of TCW and MCW improved the biomass yield by 2.2- and 2.5-fold, respectively, and adenosine, cordycepin, and polysaccharide content by 58% and 69%, 50% and 55%, and 19% and 27%, respectively. Antioxidant and cholesterol esterase (CE) inhibitory activities of the aqueous extract from O. sinensis CS1197 mycelia supplemented with TCW and MCW were high compared with those of the control, indicating that coconut water has a positive correlation with the enhanced antioxidant and CE inhibitory activities. These antioxidant and CE inhibitory responses were dependent on concentration, and the larger amounts of bioactives in O. sinensis CS1197 are beneficial in pharmaceutical formulations.

  14. The influence of addition of papain enzyme and Carboxyl Methyl Cellulose on the textural properties of Tofu

    Science.gov (United States)

    Faridah; Fachraniah; Arifien; Sari, C. M.

    2018-03-01

    Papain enzyme and carboxyl methyl cellulosa was used in tofu production as coagulant and thickener. Papain enzyme is a protease enzyme that can break proteins. Papain enzymeuseful as coagulant to replace acid and base coagulant. The goal of this study is to observe papain enzyme as coagulant and carboxyl methyl cellulose as thickener to increase characteristic of tofu. Tofu is from soy milk has been pasteurized at 70 °C with the addition of papain enzyme and carboxyl methly cellulose. The concenration of papain enzyme is varied such as 200, 400, 800, and 1000 ppm. After Temperature reachs at 90 °C, carboxyl methyl cellulosa is added in soy milk to produce tofu. This study focuses on introducing papain enzyme as coagulant as well as investigating its potential in improving tofu making process productivity. Further the present work attempts to determine the synergistic effect of combining CMC/enzyme in tofu characteristic. This research was conducted with soy milk pasteurized at 70 °C with increasing papain enzyme. Protein from tofu was determined by using Spectrophotometer UV-VIS Shimadzu UV-1800 type. The highest protein concentration of the papain enzyme was found in 1000 ppm with CMC concentration of 0.6% w/v and based on organoleptic tests that the adding CMC and enzyme papain does not effect the taste, smell, texture and color of tofu. The taste of tofu produced is similar to the taste of tofu in the market.

  15. One-year enzyme-linked immunosorbent assay follow-up of human interleukin for Da cells/leukemia inhibitory factor in blood and urine of 22 kidney transplant recipients.

    Science.gov (United States)

    Morel, D; Taupin, J L; Combe, C; Potaux, L; Gualde, N; Moreau, J F

    1994-12-15

    The cytokine human interleukin for Da cells/leukemia inhibitory factor (HILDA/LIF) exerts multiple biological effects in vitro. In mice, high circulating levels of HILDA/LIF induce a wide range of pathophysiological events, some of them closely involved with immunological and inflammatory responses. Using a sandwich ELISA recognizing the natural human HILDA/LIF molecule with a threshold of 50 pg/ml in urine and 150 pg/ml in plasma, we monitored the urine and plasma HILDA/LIF levels of 22 patients in their first year after a kidney transplant. HILDA/LIF urine excretion is increased during acute rejection, and infections also trigger heavy HILDA/LIF plasma concentrations or urine excretion. In addition, this study raises the question of HILDA/LIF involvement in post-kidney-transplant phenomena such as hypercalcemia, osteoporosis, or the reversal of anemia.

  16. Significant inhibitory impact of dibenzyl trisulfide and extracts of Petiveria alliacea on the activities of major drug-metabolizing enzymes in vitro: An assessment of the potential for medicinal plant-drug interactions.

    Science.gov (United States)

    Murray, J; Picking, D; Lamm, A; McKenzie, J; Hartley, S; Watson, C; Williams, L; Lowe, H; Delgoda, R

    2016-06-01

    Dibenzyl trisulfide (DTS) is the major active ingredient expressed in Petiveria alliacea L., a shrub widely used for a range of conditions, such as, arthritis, asthma and cancer. Given its use alone and concomitantly with prescription medicines, we undertook to investigate its impact on the activities of important drug metabolizing enzymes, the cytochromes P450 (CYP), a key family of enzymes involved in many adverse drug reactions. DTS and seven standardized extracts from the plant were assessed for their impact on the activities of CYPs 1A2, 2C19, 2C9, 2D6 and 3A4 on a fluorometric assay. DTS revealed significant impact against the activities of CYPs 1A2, 2C19 and 3A4 with IC50 values of 1.9, 4.0 and 3.2μM, respectively, which are equivalent to known standard inhibitors of these enzymes (furafylline, and tranylcypromine), and the most potent interaction with CYP1A2 displayed irreversible enzyme kinetics. The root extract, drawn with 96% ethanol (containing 2.4% DTS), displayed IC50 values of 5.6, 3.9 and 4.2μg/mL respectively, against the same isoforms, CYPs 1A2, 2C19 and 3A4. These investigations identify DTS as a valuable CYP inhibitor and P. alliacea as a candidate plant worthy of clinical trials to confirm the conclusions that extracts yielding high DTS may lead to clinically relevant drug interactions, whilst extracts yielding low levels of DTS, such as aqueous extracts, are unlikely to cause adverse herb-drug interactions. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Purification and Physico-Chemical Properties of Milk Clotting Enzyme Produced by Mucor Lamprosporus Comparable with Calf Rennet

    International Nuclear Information System (INIS)

    Moussa, L.A.; El-Fouly, M.Z.; El-Kabbany, H.; Kamel, Z.M.; Moubasher, M.H.

    1999-01-01

    Fractional precipitation of the crude enzyme produced by Mucor Lamprosporus fungus using 70% ammonium sulfate gave the highest MCA at 40 degree. Further purification of the partially purified enzyme was achieved by using Sephadex G-100 and rechromatographed on DEAE Sephadex A-50 and gave 22.5 fold then the crude enzyme with 301% enzyme recovery. Addition of NaCl to the skim milk caused pronounced decline in MCA of the enzyme while addition of 160 ppm of NaCl increased the MCA from 26.6 su/ml to 200 su/ml. The optimum temperature of the skin milk which induced the maximum activity of the purified enzyme in skim milk was found to be 40 degree while preheating the enzyme at 50 degree for 10 min caused a complete inhibition. Mild acidic condition did not affect the activity of the purified enzyme which remained almost stable till pH 6.0 while at pH 7.0 or more, the enzyme completely lost its clotting activity. The present data also showed that Mucor Lamprosporus rennin like enzyme exhibited higher activity than calf rennet

  18. Hypocholesterolemic properties of grapefruit (Citrus paradisii and shaddock (Citrus maxima juices and inhibition of angiotensin-1-converting enzyme activity

    Directory of Open Access Journals (Sweden)

    Ganiyu Oboh

    2014-12-01

    Full Text Available Grapefruit (Citrus paradisii and shaddock (Citrus maxima juices are used in folk medicine for the management of hypertension and other cardiovascular diseases, but the mechanism of action by which they exert their therapeutic action is unclear. The aim of this study was to investigate the effect of grapefruit and shaddock juices on angiotensin-1-converting enzyme (ACE activity in vitro and the hypocholesterolemic properties of the juices in rats fed a high-cholesterol diet. Grapefruit juice had higher total phenol and flavonoid contents than shaddock juice, while both juices inhibited ACE activity in a dose-dependent manner. Furthermore, administration of the juices to rats fed a high-cholesterol diet caused a significant reduction in plasma total cholesterol, triglyceride, and low-density lipoprotein–cholesterol levels and an increase in high-density lipoprotein–cholesterol levels. The inhibition of ACE activity in vitro and in vivo hypocholesterolemic effect of the juices could explain the use of the juices in the management of cardiovascular diseases.

  19. Effect of modification with 1,4-α-glucan branching enzyme on the rheological properties of cassava starch.

    Science.gov (United States)

    Li, Yadi; Li, Caiming; Gu, Zhengbiao; Hong, Yan; Cheng, Li; Li, Zhaofeng

    2017-10-01

    Steady and dynamic shear measurements were used to investigate the rheological properties of cassava starches modified using the 1,4-α-glucan branching enzyme (GBE) from Geobacillus thermoglucosidans STB02. GBE treatment lowered the hysteresis loop areas, the activation energy (E a ) values and the parameters in rheological models of cassava starch pastes. Moreover, GBE treatment increased its storage (G') and loss (G″) moduli, and decreased their tan δ (ratio of G″/G') values and frequency-dependencies. Scanning electron microscopic studies showed the selective and particular attack of GBE on starch granules, and X-ray diffraction analyses showed that GBE treatment produces significant structural changes in amylose and amylopectin. These changes demonstrate that GBE modification produces cassava starch with a more structured network and improved stability towards mechanical processing. Differential scanning calorimetric analysis and temperature sweeps indicated greater resistance to granule rupture, higher gel rigidity, and a large decrease in the rate of initial conformational ordering with increasing GBE treatment time. Pronounced changes in rheological parameters revealed that GBE modification enhances the stability of cassava starch and its applicability in the food processing industry. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. UHPLC-ESI-ORBITRAP-MS analysis of the native Mapuche medicinal plant palo negro (Leptocarpha rivularis DC. - Asteraceae) and evaluation of its antioxidant and cholinesterase inhibitory properties.

    Science.gov (United States)

    Jiménez-González, Andrea; Quispe, Cristina; Bórquez, Jorge; Sepúlveda, Beatriz; Riveros, Felipe; Areche, Carlos; Nagles, Edgar; García-Beltrán, Olimpo; Simirgiotis, Mario J

    2018-12-01

    UHPLC/ESI/MS identification of organic compounds is the first step in the majority of screening techniques for the characterization of biologically active metabolites in natural sources. This paper describes a method for the fast identification and characterisation of secondary metabolites in Leptocarpha rivularis DC. (Palo negro) extracts by HPLC/UV (DAD)-Mass Spectrometry (HPLC/MS). The plant is used for the treatment of several diseases since pre-hispanic Mapuche times. Thirty-seven compounds were detected in the aqueous edible extract for the first time including 4 sesquiterpenes, 10 flavonoids, 9 oxylipins, 2 organic acids, and 11 phenolic acids. In addition, phenolic content antioxidant and cholinesterase inhibitory activities were measured for the first time using the edible infusion. The total polyphenol content of the infusion was 230.76 ± 2.5 mmol GAE/kg dry weight, while the antioxidant activity was 176.51 ± 28.84; 195.28 ± 4.83; and 223.92 ± 2.95 mmol TE/kg dry weight, for the DPPH, ABTS, and FRAP assays, respectively. The cholinesterase inhibitory activity was 7.38 ± 0.03 and 5.74 ± 0.06 mmol GALAE/kg, for the inhibition of acetylcholinesterase AChE and BChE, respectively, showing that this plant is a candidate for the isolation of compounds that can be useful for the treatment of neurodegenerative diseases. Furthermore, this plant could serve also as a raw material for the production of dietary supplements, due to its content of polyphenolic compounds.

  1. Pancreatic Enzymes

    Science.gov (United States)

    ... Contact Us DONATE NOW GENERAL DONATION PURPLESTRIDE Pancreatic enzymes Home Facing Pancreatic Cancer Living with Pancreatic Cancer ... and see a registered dietitian. What are pancreatic enzymes? Pancreatic enzymes help break down fats, proteins and ...

  2. Antioxidant properties of digestive enzyme-treated fibre-rich fractions from wheat, finger millet, pearl millet and sorghum: A comparative evaluation

    Directory of Open Access Journals (Sweden)

    Aisha Siddiq A.

    2015-12-01

    Full Text Available Whole grains are rich in antioxidant components (AC, most of which are bound to fibre fraction and released during digestion. The study investigated the effect of digestive enzymes on the antioxidant properties of fibre-rich fractions from wheat (Triticum aestivum, finger millet (Eleusine coracana, pearl millet (Pennisetum typhoides and sorghum (Sorghum bicolor. Coarse (CF and fine fractions (FF of milled flour were separated using a standard sieve and analysed for nutritional composition, AC extractable in different solvents and antioxidant activity (AA in untreated and enzyme-treated fractions. The CF had a higher range of insoluble dietary fibre (17.26–20.93% than FF (10.65–17.29%. The highest amount of polyphenols and flavonoids was extractable in different solvents from finger millet and pearl millet, respectively. FF of pearl millet showed higher total AA in all solvents. Enzyme-treated samples had a much higher content of AC as well as higher total AA. Free radical scavenging assay revealed that enzyme-treated millet flours had higher activity in comparison to wheat. Between fractions, wheat exhibited variable results. Among millets, CF of finger millet and FF of pearl millet and sorghum had higher AA. In conclusion, digestive enzyme treatment released more AC from grains, and exhibited a higher AA.

  3. The inhibitory effect of apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3G (APOBEC3G) and its family members on the activity of cellular microRNAs.

    Science.gov (United States)

    Zhang, Hui

    2010-01-01

    The apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3G (APOBEC3G or APOBEC3G) and its fellow cytidine deaminase family members are potent restrictive factors for human immunodeficiency virus type 1 (HIV-1) and many other retroviruses. However, the cellular function of APOBEC3G remains to be further clarified. It has been reported that APOBEC3s can restrict the mobility of endogenous retroviruses and LTR-retrotransposons, suggesting that they can maintain stability in host genomes. However, APOBEC3G is normally cytoplasmic. Further studies have demonstrated that it is associated with an RNase-sensitive high molecular mass (HMM) and located in processing bodies (P-bodies) of replicating T-cells, indicating that the major cellular function of APOBEC3G seems to be related to P-body-related RNA processing and metabolism. As the function of P-body is closely related to miRNA activity, APOBEC3G could affect the miRNA function. Recent studies have demonstrated that APOBEC3G and its family members counteract miRNA-mediated repression of protein translation. Further, APOBEC3G enhances the association of miRNA-targeted mRNA with polysomes, and facilitates the dissociation of miRNA-targeted mRNA from P-bodies. As such, APOBEC3G regulate the activity of cellular miRNAs. Whether this function is related to its potent antiviral activity remains to be further determined.

  4. Drug Delivery by an Enzyme-Mediated Cyclization of a Lipid Prodrug with Unique Bilayer-Formation Properties

    DEFF Research Database (Denmark)

    Linderoth, Lars; Peters, Günther H.j.; Madsen, Robert

    2009-01-01

    Special delivery: Liposomal drug-delivery systems in which prodrugs are activated specifically by disease-associated enzymes have great potential for the treatment of severe diseases, such as cancer. A new type of phospholipid-based prodrug has the ability to form stable small unilamellar vesicle...... (see picture). Activation of the prodrug vesicles by the enzyme sPLA2 initiates a cyclization reaction, which leads to the release of the drug....

  5. Purification of camel liver catalase by zinc chelate affinity chromatography and pH gradient elution: An enzyme with interesting properties.

    Science.gov (United States)

    Chafik, Abdelbasset; Essamadi, Abdelkhalid; Çelik, Safinur Yildirim; Mavi, Ahmet

    2017-12-01

    Climate change and increasing temperatures are global concerns. Camel (Camelus dromedarius) lives most of its life under high environmental stress in the desert and represent ideal model for studying desert adaptation among mammals. Catalase plays a key role in protecting cells against oxidative stress. For the first time, catalase from camel liver was purified to homogeneity by zinc chelate affinity chromatography using pH gradient elution, a better separation was obtained. A purification fold of 201.81 with 1.17% yield and a high specific activity of 1132539.37U/mg were obtained. The native enzyme had a molecular weight of 268kDa and was composed of four subunits of equal size (65kDa). The enzyme showed optimal activity at a temperature of 45°C and pH 7.2. Thiol reagents, β-Mercaptoethanol and D,L-Dithiothreitol, inhibited the enzyme activity. The enzyme was inhibited by Al 3+ , Cd 2+ and Mg 2+ , whereas Ca 2+ , Co 2+ and Ni 2+ stimulated the catalase activity. Reduced glutathione has no effect on catalase activity. The K m and V max of the enzyme for hydrogen peroxide were 37.31mM and 6185157U/mg, respectively. Sodium azide inhibited the enzyme noncompetitively with K i value of 14.43μM, the IC 50 was found to be 16.71μM. The properties of camel catalase were different comparing to those of mammalian species. Relatively higher molecular weight, higher optimum temperature, protection of reduced glutathione from hydrogen peroxide oxidation and higher affinity for hydrogen peroxide and sodium azide, these could be explained by the fact that camel is able to live in the intense environmental stress in the desert. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. PHYSICOCHEMICAL PROPERTIES OF THE PROTEOLYTIC ENZYME FROM THE LATEX OF THE MILKWEED, ASCLEPIAS SPECIOSA TORR. SOME COMPARISONS WITH OTHER PROTEASES

    Science.gov (United States)

    Winnick, Theodore; Davis, Alva R.; Greenberg, David M.

    1940-01-01

    1. The kinetics of milk clotting by asclepain, the protease of Asclepias speciosa, were investigated. At higher concentrations of enzyme, the clotting time was inversely proportional to the enzyme concentration. 2. The digestion of casein and hemoglobin in 6.6 M urea by asclepain follows the second order reaction rate. The rate was roughly second order for casein in water. 3. Evaluation of the nature of the enzyme-substrate intermediate indicates that one molecule of asclepain combines with one molecule of casein or hemoglobin in urea solution. 4. Inhibition by the reaction products was deduced from the fact that the digestion velocity of hemoglobin in urea solution varied with the asclepain concentration in agreement with the Schütz-Borissov rule. PMID:19873155

  7. Investigation of cytochrome P450 inhibitory properties of maslinic acid, a bioactive compound from Olea europaea L., and its structure-activity relationship.

    Science.gov (United States)

    Sun, Min; Tang, Yu; Ding, Tonggui; Liu, Mingyao; Wang, Xin

    2015-01-15

    Maslinic acid (MA), the main pentacyclic triterpene of Olea europaea L. fruit, possesses a variety of pharmacological actions, including hypoglycemic, antioxidant, cardioprotective and antitumoral activities. Despite its importance, little is known about its effects on the cytochrome P450 (CYP) activity in both humans and animals. Therefore, the aim of this study was to investigate the effects of MA on the CYP 1A2, 2C9/11, 2D1/6, 2E1 and 3A2/4 activities by human and rat liver microsomes and specific CYP isoforms. In humans, MA only weakly inhibited CYP3A4 activity in human liver microsomes and specific CYP3A4 isoform with IC50 value at 46.1 and 62.3µM, respectively. In rats, MA also exhibited weak inhibition on CYP2C11, CYP2E1 and CYP3A2 activities with IC50 values more than 100µM. Enzyme kinetic studies showed that the MA was not only a competitive inhibitor of CYP3A4 in humans, but also a competitive inhibitor of CYP2C11 and 3A2 in rats, with Ki of 18.4, 98.7 and 66.3µM, respectively. Moreover, the presence of hydroxyl group at C-2 position of triterpenic acid in MA compared with oleanolic acid could magnify its competitive inhibition on human CYP3A4 activity. The relatively high Ki values of MA would have a low potential to cause the possible toxicity and drug interactions involving CYP enzymes, thus suggesting a sufficient safety for its putative use as a nutraceutical taken together with drugs. Copyright © 2014 Elsevier GmbH. All rights reserved.

  8. In vivo hypotensive effect and in vitro inhibitory activity of some Cyperaceae species

    Directory of Open Access Journals (Sweden)

    Monica Lacerda Lopes Martins

    2013-12-01

    Full Text Available In 1820, French naturalist August Saint Hillaire, during a visit in Espírito Santo (ES, a state in southeastern Brazil, reported a popular use of Cyperaceae species as antidote to snake bites. The plant may even have a hypotensive effect, though it was never properly researched. The in vitro inhibitory of the angiotensin converting enzyme (ACE activity of eigth ethanolic extracts of Cyperaceae was evaluated by colorimetric assay. Total phenolic and flavonoids were determined using colorimetric assay. The hypotensive effect of the active specie (Rhychonospora exaltata, ERE and the in vivo ACE assay was measured in vivo using male Wistar Kyoto (ERE, 0.01-100mg/kg, with acetylcholine (ACh as positive control (5 µg/kg, i.v.. The evaluation of ACE in vivo inhibitory effect was performed comparing the mean arterial pressure before and after ERE (10 mg/kg in animals which received injection of angiotensin I (ANG I; 0,03, 03 and 300 µg/kg, i.v.. Captopril (30 mg/kg was used as positive control. Bulbostylis capillaris (86.89 ± 15.20% and ERE (74.89 ± 11.95%, ERE were considered active in the in vitro ACE inhibition assay, at 100 µg/mL concentration. ACh lead to a hypotensive effect before and after ERE's curve (-40±5% and -41±3%. ERE showed a dose-dependent hypotensive effect and a in vivo ACE inhibitory effect. Cyperaceae species showed an inhibitory activity of ACE, in vitro, as well as high content of total phenolic and flavonoids. ERE exhibited an inhibitory effect on both in vitro and in vivo ACE. The selection of species used in popular medicine as antidotes, along with the in vitro assay of ACE inhibition, might be a biomonitoring method for the screening of new medicinal plants with hypotensive properties.

  9. Antioxidant and ACE Inhibitory Bioactive Peptides Purified from Egg Yolk Proteins

    Directory of Open Access Journals (Sweden)

    Marwa Yousr

    2015-12-01

    Full Text Available Protein by-products from the extraction of lecithin from egg yolk can be converted into value-added products, such as bioactive hydrolysates and peptides that have potential health enhancing antioxidant, and antihypertensive properties. In this study, the antioxidant and angiotensin converting enzyme (ACE inhibitory activities of peptides isolated and purified from egg yolk protein were investigated. Defatted egg yolk was hydrolyzed using pepsin and pancreatin and sequentially fractionated by ultrafiltration, followed by gel filtration to produce egg yolk gel filtration fractions (EYGF. Of these, two fractions, EYGF-23 and EYGF-33, effectively inhibited the peroxides and thiobarbituric acid reactive substance (TBARS in an oxidizing linoleic acid model system. The antioxidant mechanism involved superoxide anion and hydroxyl radicals scavenging and ferrous chelation. The presence of hydrophobic amino acids such as tyrosine (Y and tryptophan (W, in sequences identified by LC-MS as WYGPD (EYGF-23 and KLSDW (EYGF-33, contributed to the antioxidant activity and were not significantly different from the synthetic BHA antioxidant. A third fraction (EYGF-56 was also purified from egg yolk protein by gel filtration and exhibited high ACE inhibitory activity (69% and IC50 value (3.35 mg/mL. The SDNRNQGY peptide (10 mg/mL had ACE inhibitory activity, which was not significantly different from that of the positive control captopril (0.5 mg/mL. In addition, YPSPV in (EYGF-33 (10 mg/mL had higher ACE inhibitory activity compared with captopril. These findings indicated a substantial potential for producing valuable peptides with antioxidant and ACE inhibitory activity from egg yolk.

  10. Antioxidant and ACE Inhibitory Bioactive Peptides Purified from Egg Yolk Proteins.

    Science.gov (United States)

    Yousr, Marwa; Howell, Nazlin

    2015-12-07

    Protein by-products from the extraction of lecithin from egg yolk can be converted into value-added products, such as bioactive hydrolysates and peptides that have potential health enhancing antioxidant, and antihypertensive properties. In this study, the antioxidant and angiotensin converting enzyme (ACE) inhibitory activities of peptides isolated and purified from egg yolk protein were investigated. Defatted egg yolk was hydrolyzed using pepsin and pancreatin and sequentially fractionated by ultrafiltration, followed by gel filtration to produce egg yolk gel filtration fractions (EYGF). Of these, two fractions, EYGF-23 and EYGF-33, effectively inhibited the peroxides and thiobarbituric acid reactive substance (TBARS) in an oxidizing linoleic acid model system. The antioxidant mechanism involved superoxide anion and hydroxyl radicals scavenging and ferrous chelation. The presence of hydrophobic amino acids such as tyrosine (Y) and tryptophan (W), in sequences identified by LC-MS as WYGPD (EYGF-23) and KLSDW (EYGF-33), contributed to the antioxidant activity and were not significantly different from the synthetic BHA antioxidant. A third fraction (EYGF-56) was also purified from egg yolk protein by gel filtration and exhibited high ACE inhibitory activity (69%) and IC50 value (3.35 mg/mL). The SDNRNQGY peptide (10 mg/mL) had ACE inhibitory activity, which was not significantly different from that of the positive control captopril (0.5 mg/mL). In addition, YPSPV in (EYGF-33) (10 mg/mL) had higher ACE inhibitory activity compared with captopril. These findings indicated a substantial potential for producing valuable peptides with antioxidant and ACE inhibitory activity from egg yolk.

  11. Inhibitory potency of Withania somnifera extracts against DPP-4: an ...

    African Journals Online (AJOL)

    Materials and Methods: Young and matured fresh roots, leaves, and fruits of WS plant extract were considered and were systematically evaluated for DPP-4 inhibitory activity using in vitro method, enzyme kinetics, phytochemical analysis, RP-HPLC, LCMS and 1H and 13C NMR method and structure-activity relationship ...

  12. Inhibitory coupling between inhibitory interneurons in the spinal cord dorsal horn

    Directory of Open Access Journals (Sweden)

    Ribeiro-da-Silva Alfredo

    2009-05-01

    Full Text Available Abstract Local inhibitory interneurons in the dorsal horn play an important role in the control of excitability at the segmental level and thus determine how nociceptive information is relayed to higher structures. Regulation of inhibitory interneuron activity may therefore have critical consequences on pain perception. Indeed, disinhibition of dorsal horn neuronal networks disrupts the balance between excitation and inhibition and is believed to be a key mechanism underlying different forms of pain hypersensitivity and chronic pain states. In this context, studying the source and the synaptic properties of the inhibitory inputs that the inhibitory interneurons receive is important in order to predict the impact of drug action at the network level. To address this, we studied inhibitory synaptic transmission in lamina II inhibitory interneurons identified under visual guidance in spinal slices taken from transgenic mice expressing enhanced green fluorescent protein (EGFP under the control of the GAD promoter. The majority of these cells fired tonically to a long depolarizing current pulse. Monosynaptically evoked inhibitory postsynaptic currents (eIPSCs in these cells were mediated by both GABAA and glycine receptors. Consistent with this, both GABAA and glycine receptor-mediated miniature IPSCs were recorded in all of the cells. These inhibitory inputs originated at least in part from local lamina II interneurons as verified by simultaneous recordings from pairs of EGFP+ cells. These synapses appeared to have low release probability and displayed potentiation and asynchronous release upon repeated activation. In summary, we report on a previously unexamined component of the dorsal horn circuitry that likely constitutes an essential element of the fine tuning of nociception.

  13. Changes in physicochemical properties and in vitro starch digestion of native and extruded maize flours subjected to branching enzyme and maltogenic α-amylase treatment.

    Science.gov (United States)

    Román, Laura; Martínez, Mario M; Rosell, Cristina M; Gómez, Manuel

    2017-08-01

    Extrusion is an increasingly used type of processing which combined with enzymatic action could open extended possibilities for obtaining clean label modified flours. In this study, native and extruded maize flours were modified using branching enzyme (B) and a combination of branching enzyme and maltogenic α-amylase (BMA) in order to modulate their hydrolysis properties. The microstructure, pasting properties, in vitro starch hydrolysis and resistant starch content of the flours were investigated. Whereas BMA treatment led to greater number of holes on the granule surface in native samples, B and BMA extruded samples showed rougher surfaces with cavities. A reduction in the retrogradation trend was observed for B and BMA native flours, in opposition to the flat pasting profile of their extruded counterparts. The glucose release increased gradually for native flours as the time of reaction did, whereas for extruded flours a fast increase of glucose release was observed during the first minutes of reaction, and kept till the end, indicating a greater accessibility to their porous structure. These results suggested that, in enzymatically treated extruded samples, changes produced at larger hierarchical levels in their starch structure could have masked a slowdown in the starch digestion properties. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Effect of Alpinia zerumbet components on antioxidant and skin diseases-related enzymes

    Directory of Open Access Journals (Sweden)

    Chompoo Jamnian

    2012-07-01

    Full Text Available Abstract Background The skin is chronically exposed to endogenous and environmental pro-oxidant agents, leading to the harmful generation of reactive oxygen species. Antioxidant is vital substances which possess the ability to protect the body from damage cause by free radicals induce oxidative stress. Alpinia zerumbet, a traditionally important economic plant in Okinawa, contains several interesting bioactive constituents and possesses health promoting properties. In this regard, we carried out to test the inhibitory effect of crude extracts and isolated compounds from A. zerumbet on antioxidant and skin diseases-related enzymes. Methods The antioxidant activities were examined by DPPH, ABTS and PMS-NADH radical scavenging. Collagenase, elastase, hyaluronidase and tyrosinase were designed for enzymatic activities to investigate the inhibitory properties of test samples using a continuous spectrophotometric assay. The inhibitory capacity of test samples was presented at half maximal inhibitory concentration (IC50. Results The results showed that aqueous extract of the rhizome was found to have greater inhibitory effects than the others on both of antioxidant and skin diseases-related enzymes. Furthermore, 5,6-dehydrokawain (DK, dihydro-5,6-dehydrokawain (DDK and 8(17,12-labdadiene-15,16-dial (labdadiene, isolated from rhizome, were tested for antioxidant and enzyme inhibitions. We found that DK showed higher inhibitory activities on DPPH, ABTS and PMS-NADH scavenging (IC50 = 122.14 ± 1.40, 110.08 ± 3.34 and 127.78 ± 4.75 μg/ml, respectively. It also had stronger inhibitory activities against collagenase, elastase, hyaluronidase and tyrosinase (IC50 = 24.93 ± 0.97, 19.41 ± 0.61, 19.48 ± 0.24 and 76.67 ± 0.50 μg/ml, respectively than DDK and labdadiene. Conclusion Our results indicate that the rhizome aqueous extract proved to be the source of bioactive compounds against enzymes responsible for

  15. Cucurbitacin delta 23-reductase from the fruit of Cucurbita maxima var. Green Hubbard. Physicochemical and fluorescence properties and enzyme-ligand interactions.

    Science.gov (United States)

    Dirr, H W; Schabort, J C; Weitz, C

    1986-02-01

    Cucurbitacin delta 23-reductase from Cucurbita maxima var. Green Hubbard fruit displays an apparent Mr of 32,000, a Stokes radius of 263 nm and a diffusion coefficient of 8.93 X 10(-7) cm2 X s-1. The enzyme appears to possess a homogeneous dimeric quaternary structure with a subunit Mr of 15,000. Two tryptophan and fourteen tyrosine residues per dimer were found. Emission spectral properties of the enzyme and fluorescence quenching by iodide indicate the tryptophan residues to be buried within the protein molecule. In the pH range 5-7, where no conformational changes were detected, protonation of a sterically related ionizable group with a pK of approx. 6.0 markedly influenced the fluorescence of the tryptophan residues. Protein fluorescence quenching was employed to determine the dissociation constants for binding of NADPH (Kd 17 microM), NADP+ (Kd 30 microM) and elaterinide (Kd 227 microM). Fluorescence energy transfer between the tryptophan residues and enzyme-bound NADPH was observed.

  16. Physical structure and absorption properties of tailor-made porous starch granules produced by selected amylolytic enzymes.

    Directory of Open Access Journals (Sweden)

    Yi-Seul Jung

    Full Text Available Porous starch granules (PSGs with various pores and cavity sizes were prepared by amylolysis enzymes. The greatest hydrolysis rate on corn starch granule was observed with α-amylase, followed by gluco- and β-amylases. Temperature increase enhanced glucoamylase reaction rate more drastically than other enzyme treatments. Final hydrolysis level with glucoamylase reached to 66.9%, close to 67.5% of α-amylolysis. The α-amylase-treated PSGs displayed the greatest pore size and ratio of cavity-to-granule diameters. Gelatinization onset temperatures of PSGs increased to 72.1 (α-, 68.7 (β-, and 68.1°C (gluco-amylolysis after 8 h; enthalpy changes of β- and gluco-amylase-treated PSGs increased to 13.4, and 13.1 J/g but α-amylase-treated one showed slightly reduced value of 8.5 J/g. Water holding capacities of PSGs were 209.7 (α-, 94.6 (β-, and 133.8% (gluco-amylolysis, and the untreated control had 89.1%; oil holding capacities of them showed 304.5, 182.7, and 211.5%, respectively, while the untreated control had 161.8%. Thus, enzyme types and their reaction conditions can be applied to generate desirable cavity and pore sizes in starch granules. This biocatalytic approach could contribute to develop tailor-made PSGs with distinct internal structure for specific uses in wide range of food, pharmaceutical and other industrial applications.

  17. RC1339/APRc from Rickettsia conorii is a novel aspartic protease with properties of retropepsin-like enzymes.

    Directory of Open Access Journals (Sweden)

    Rui Cruz

    2014-08-01

    Full Text Available Members of the species Rickettsia are obligate intracellular, gram-negative, arthropod-borne pathogens of humans and other mammals. The life-threatening character of diseases caused by many Rickettsia species and the lack of reliable protective vaccine against rickettsioses strengthens the importance of identifying new protein factors for the potential development of innovative therapeutic tools. Herein, we report the identification and characterization of a novel membrane-embedded retropepsin-like homologue, highly conserved in 55 Rickettsia genomes. Using R. conorii gene homologue RC1339 as our working model, we demonstrate that, despite the low overall sequence similarity to retropepsins, the gene product of rc1339 APRc (for Aspartic Protease from Rickettsia conorii is an active enzyme with features highly reminiscent of this family of aspartic proteases, such as autolytic activity impaired by mutation of the catalytic aspartate, accumulation in the dimeric form, optimal activity at pH 6, and inhibition by specific HIV-1 protease inhibitors. Moreover, specificity preferences determined by a high-throughput profiling approach confirmed common preferences between this novel rickettsial enzyme and other aspartic proteases, both retropepsins and pepsin-like. This is the first report on a retropepsin-like protease in gram-negative intracellular bacteria such as Rickettsia, contributing to the analysis of the evolutionary relationships between the two types of aspartic proteases. Additionally, we have also shown that APRc is transcribed and translated in R. conorii and R. rickettsii and is integrated into the outer membrane of both species. Finally, we demonstrated that APRc is sufficient to catalyze the in vitro processing of two conserved high molecular weight autotransporter adhesin/invasion proteins, Sca5/OmpB and Sca0/OmpA, thereby suggesting the participation of this enzyme in a relevant proteolytic pathway in rickettsial life-cycle. As a

  18. Physical structure and absorption properties of tailor-made porous starch granules produced by selected amylolytic enzymes

    Science.gov (United States)

    Jung, Yi-seul; Lee, Byung-Hoo

    2017-01-01

    Porous starch granules (PSGs) with various pores and cavity sizes were prepared by amylolysis enzymes. The greatest hydrolysis rate on corn starch granule was observed with α-amylase, followed by gluco- and β-amylases. Temperature increase enhanced glucoamylase reaction rate more drastically than other enzyme treatments. Final hydrolysis level with glucoamylase reached to 66.9%, close to 67.5% of α-amylolysis. The α-amylase-treated PSGs displayed the greatest pore size and ratio of cavity-to-granule diameters. Gelatinization onset temperatures of PSGs increased to 72.1 (α-), 68.7 (β-), and 68.1°C (gluco-amylolysis) after 8 h; enthalpy changes of β- and gluco-amylase-treated PSGs increased to 13.4, and 13.1 J/g but α-amylase-treated one showed slightly reduced value of 8.5 J/g. Water holding capacities of PSGs were 209.7 (α-), 94.6 (β-), and 133.8% (gluco-amylolysis), and the untreated control had 89.1%; oil holding capacities of them showed 304.5, 182.7, and 211.5%, respectively, while the untreated control had 161.8%. Thus, enzyme types and their reaction conditions can be applied to generate desirable cavity and pore sizes in starch granules. This biocatalytic approach could contribute to develop tailor-made PSGs with distinct internal structure for specific uses in wide range of food, pharmaceutical and other industrial applications. PMID:28727742

  19. Phosphoribosylpyrophosphate synthetase of Escherichia coli. Properties of the purified enzyme and primary structure of the prs gene

    DEFF Research Database (Denmark)

    Hove-Jensen, Bjarne; Harlow, Kenneth W.; King, Cheryl J.

    1986-01-01

    of ADP. The nucleotide sequence of the E. coli prs gene has been determined and the coding segment established. The deduced amino acid sequence of P-Rib-PP synthetase contained 314 amino acid residues and the molecular weight was calculated as 34,060. The initiation site of transcription was determined......Phosphoribosylpyrophosphate (P-Rib-PP) synthetase of Escherichia coli has been purified to near homogeneity from a strain harboring the prs gene, encoding P-Rib-PP synthetase, on a multicopy plasmid. Analysis of the enzyme showed that it required inorganic phosphate for activity and for stability...

  20. Lactosylamidine-based affinity purification for cellulolytic enzymes EG I and CBH I from Hypocrea jecorina and their properties.

    Science.gov (United States)

    Ogata, Makoto; Kameshima, Yumiko; Hattori, Takeshi; Michishita, Kousuke; Suzuki, Tomohiro; Kawagishi, Hirokazu; Totani, Kazuhide; Hiratake, Jun; Usui, Taichi

    2010-12-10

    Selective adsorption and separation of β-glucosidase, endo-acting endo-β-(1→4)-glucanase I (EG I), and exo-acting cellobiohydrolase I (CBH I) were achieved by affinity chromatography with β-lactosylamidine as ligand. A crude cellulase preparation from Hypocrea jecorina served as the source of enzyme. When crude cellulase was applied to the lactosylamidine-based affinity column, β-glucosidase appeared in the unbound fraction. By contrast, EG I and CBH I were retained on the column and then separated from each other by appropriately adjusting the elution conditions. The relative affinities of the enzymes, based on their column elution conditions, were strongly dependent on the ligand. The highly purified EG I and CBH I, obtained by affinity chromatography, were further purified by Mono P and DEAE chromatography, respectively. EG I and CBH I cleave only at the phenolic bond in p-nitrophenyl glycosides with lactose and N-acetyllactosamine (LacNAc). By contrast, both scissile bonds in p-nitrophenyl glycosides with cellobiose were subject to hydrolysis although with important differences in their kinetic parameters. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. Enzyme Informatics

    Science.gov (United States)

    Alderson, Rosanna G.; Ferrari, Luna De; Mavridis, Lazaros; McDonagh, James L.; Mitchell, John B. O.; Nath, Neetika

    2012-01-01

    Over the last 50 years, sequencing, structural biology and bioinformatics have completely revolutionised biomolecular science, with millions of sequences and tens of thousands of three dimensional structures becoming available. The bioinformatics of enzymes is well served by, mostly free, online databases. BRENDA describes the chemistry, substrate specificity, kinetics, preparation and biological sources of enzymes, while KEGG is valuable for understanding enzymes and metabolic pathways. EzCatDB, SFLD and MACiE are key repositories for data on the chemical mechanisms by which enzymes operate. At the current rate of genome sequencing and manual annotation, human curation will never finish the functional annotation of the ever-expanding list of known enzymes. Hence there is an increasing need for automated annotation, though it is not yet widespread for enzyme data. In contrast, functional ontologies such as the Gene Ontology already profit from automation. Despite our growing understanding of enzyme structure and dynamics, we are only beginning to be able to design novel enzymes. One can now begin to trace the functional evolution of enzymes using phylogenetics. The ability of enzymes to perform secondary functions, albeit relatively inefficiently, gives clues as to how enzyme function evolves. Substrate promiscuity in enzymes is one example of imperfect specificity in protein-ligand interactions. Similarly, most drugs bind to more than one protein target. This may sometimes result in helpful polypharmacology as a drug modulates plural targets, but also often leads to adverse side-effects. Many cheminformatics approaches can be used to model the interactions between druglike molecules and proteins in silico. We can even use quantum chemical techniques like DFT and QM/MM to compute the structural and energetic course of enzyme catalysed chemical reaction mechanisms, including a full description of bond making and breaking. PMID:23116471

  2. Improving soil enzyme activities and related quality properties of reclaimed soil by applying weathered coal in opencast-mining areas of the Chinese loess plateau

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hua [College of Environment and Resources, Shanxi University, Taiyuan (China); CAS/Shandong Provincial Key Laboratory of Coastal Environmental Process, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences (CAS), Yantai (China); Shao, Hongbo [CAS/Shandong Provincial Key Laboratory of Coastal Environmental Process, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences (CAS), Yantai (China); Institute for Life Sciences, Qingdao University of Science and Technology (QUST), Qingdao (China); Li, Weixiang; Bi, Rutian [Shanxi Agricultural University, Taigu (China); Bai, Zhongke [Department of Land Science Technology, University of Geosciences, Beijing (China)

    2012-03-15

    There are many problems for the reclaimed soil in opencast-mining areas of the Loess Plateau of China such as poor soil structure and extreme poverty in soil nutrients and so on. For the sake of finding a better way to improve soil quality, the current study was to apply the weathered coal for repairing soil media and investigate the physicochemical properties of the reclaimed soil and the changes in enzyme activities after planting Robinia pseucdoacacia. The results showed that the application of the weathered coal significantly improved the quality of soil aggregates, increased the content of water stable aggregates, and the organic matter, humus, and the cation exchange capacity of topsoil were significantly improved, but it did not have a significant effect on soil pH. Planting R. pseucdoacacia significantly enhanced the activities of soil catalase, urease, and invertase, but the application of the weathered coal inhibited the activity of catalase. Although the application of appropriate weathered coal was able to significantly increase urease activity, the activities of catalase, urease, or invertase had a close link with the soil profile levels and time. This study suggests that applying weathered coals could improve the physicochemical properties and soil enzyme activities of the reclaimed soil in opencast-mining areas of the Loess Plateau of China and the optimum applied amount of the weathered coal for reclaimed soil remediation is about 27 000 kg hm{sup -2}. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Extracts, Anthocyanins and Procyanidins from Aronia melanocarpa as Radical Scavengers and Enzyme Inhibitors

    Directory of Open Access Journals (Sweden)

    Hilde Barsett

    2013-03-01

    Full Text Available Extracts, subfractions, isolated anthocyanins and isolated procyanidins B2, B5 and C1 from the berries and bark of Aronia melanocarpa were investigated for their antioxidant and enzyme inhibitory activities. Four different bioassays were used, namely scavenging of the diphenylpicrylhydrazyl (DPPH radical, inhibition of 15-lipoxygenase (15-LO, inhibition of xanthine oxidase (XO and inhibition of α-glucosidase. Among the anthocyanins, cyanidin 3-arabinoside possessed the strongest and cyanidin 3-xyloside the weakest radical scavenging and enzyme inhibitory activity. These effects seem to be influenced by the sugar units linked to the anthocyanidin. Subfractions enriched in procyanidins were found to be potent α-glucosidase inhibitors; they possessed high radical scavenging properties, strong inhibitory activity towards 15-LO and moderate inhibitory activity towards XO. Trimeric procyanidin C1 showed higher activity in the biological assays compared to the dimeric procyanidins B2 and B5. This study suggests that different polyphenolic compounds of A. melanocarpa can have beneficial effects in reducing blood glucose levels due to inhibition of α-glucosidase and may have a potential to alleviate oxidative stress.

  4. Catalytic Properties and Immobilization Studies of Catalase from Malva sylvestris L.

    OpenAIRE

    Arabaci, G.; Usluoglu, A.

    2013-01-01

    Catalase was partially purified from Malva sylvestris L. and immobilized onto chitosan. Then, its catalytic properties were investigated. (NH4)2SO4 precipitation and dialysis were performed in the extracted enzyme. Further purification was performed with sephadex G-200 column. Kinetic studies of the purified enzyme activity were measured and characterized. The inhibitory effects of KCN, NaN3, CuSO4, and EDTA on M. sylvestris L. catalase activity were observed except NaCl. Furthermore, M. sylv...

  5. Preparation of submicrometer monodispersed magnetic silica particles using a novel water in oil microemulsion: properties and application for enzyme immobilization.

    Science.gov (United States)

    Tuttolomondo, Maria Victoria; Villanueva, Maria Emilia; Alvarez, Gisela Solange; Desimone, Martín Federico; Díaz, Luis Eduardo

    2013-10-01

    The synthesis of monodispersed magnetic silica nanoparticles (MSN) is described using a water-in-oil reverse microemulsion system that does not require the use of co-surfactants. Sodium silicate, Tween 20 as a neutral surfactant and 1-butanol as the organic phase were used. There are several advantages of the proposed method including a saturation magnetization value of 10 emu/g for the particles obtained, uniformity of size and that they are easily functionalized to bind urease covalently. Moreover, the intra-day, inter-day and long-term stability results confirm that the procedure was successful and the enzyme-linked MSNs were stable over repeated uses and storage retaining more than 75% activity after 4 months.

  6. Structural and Kinetic Properties of the Aldehyde Dehydrogenase NahF, a Broad Substrate Specificity Enzyme for Aldehyde Oxidation.

    Science.gov (United States)

    Coitinho, Juliana B; Pereira, Mozart S; Costa, Débora M A; Guimarães, Samuel L; Araújo, Simara S; Hengge, Alvan C; Brandão, Tiago A S; Nagem, Ronaldo A P

    2016-09-27

    The salicylaldehyde dehydrogenase (NahF) catalyzes the oxidation of salicylaldehyde to salicylate using NAD(+) as a cofactor, the last reaction of the upper degradation pathway of naphthalene in Pseudomonas putida G7. The naphthalene is an abundant and toxic compound in oil and has been used as a model for bioremediation studies. The steady-state kinetic parameters for oxidation of aliphatic or aromatic aldehydes catalyzed by 6xHis-NahF are presented. The 6xHis-NahF catalyzes the oxidation of aromatic aldehydes with large kcat/Km values close to 10(6) M(-1) s(-1). The active site of NahF is highly hydrophobic, and the enzyme shows higher specificity for less polar substrates than for polar substrates, e.g., acetaldehyde. The enzyme shows α/β folding with three well-defined domains: the oligomerization domain, which is responsible for the interlacement between the two monomers; the Rossmann-like fold domain, essential for nucleotide binding; and the catalytic domain. A salicylaldehyde molecule was observed in a deep pocket in the crystal structure of NahF where the catalytic C284 and E250 are present. Moreover, the residues G150, R157, W96, F99, F274, F279, and Y446 were thought to be important for catalysis and specificity for aromatic aldehydes. Understanding the molecular features responsible for NahF activity allows for comparisons with other aldehyde dehydrogenases and, together with structural information, provides the information needed for future mutational studies aimed to enhance its stability and specificity and further its use in biotechnological processes.

  7. Magnetically responsive enzyme powders

    Energy Technology Data Exchange (ETDEWEB)

    Pospiskova, Kristyna, E-mail: kristyna.pospiskova@upol.cz [Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Safarik, Ivo, E-mail: ivosaf@yahoo.com [Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Department of Nanobiotechnology, Institute of Nanobiology and Structural Biology of GCRC, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic)

    2015-04-15

    Powdered enzymes were transformed into their insoluble magnetic derivatives retaining their catalytic activity. Enzyme powders (e.g., trypsin and lipase) were suspended in various liquid media not allowing their solubilization (e.g., saturated ammonium sulfate and highly concentrated polyethylene glycol solutions, ethanol, methanol, 2-propanol) and subsequently cross-linked with glutaraldehyde. Magnetic modification was successfully performed at low temperature in a freezer (−20 °C) using magnetic iron oxides nano- and microparticles prepared by microwave-assisted synthesis from ferrous sulfate. Magnetized cross-linked enzyme powders were stable at least for two months in water suspension without leakage of fixed magnetic particles. Operational stability of magnetically responsive enzymes during eight repeated reaction cycles was generally without loss of enzyme activity. Separation of magnetically modified cross-linked powdered enzymes from reaction mixtures was significantly simplified due to their magnetic properties. - Highlights: • Cross-linked enzyme powders were prepared in various liquid media. • Insoluble enzymes were magnetized using iron oxides particles. • Magnetic iron oxides particles were prepared by microwave-assisted synthesis. • Magnetic modification was performed under low (freezing) temperature. • Cross-linked powdered trypsin and lipase can be used repeatedly for reaction.

  8. Inhibitory Effect of Nisin on Listeria monocytogenes Inoculated into Surimi and Minced Meat

    Directory of Open Access Journals (Sweden)

    Masoud Rezaei

    2012-02-01

    Full Text Available Background & Objective: Listeria monocytogenes has already established as an important food born pathogen which induce listeriosis in human. Use of bacteriocins to provide food safety has been increased dramatically. Nisin has a wide spectrum inhibitory effect than the other bacteriocins and inhibits food-borne pathogens such as L. monocytogenes and many other Gram-positive spoilage microorganisms. The purpose of this study was to investigate the inhibitory effect of Nisin on population of Listeria monocytogenes and the role of changes in food components on the antilisterial properties of Nisin. Materials & Methods: The minced meat and surimi samples were inoculated by 1×104 cfu/g of L. monocytogenes. Then samples exposed to Nisin at the levels of 500 or 1000 IU/g were prepared. All treatments after packaging in plastic bags were kept for 12 days at refrigerator temperature. Samples were cultured on CHROMagarTM Listeria every 2 days and the number of listeria monocytogenes was counted. Results: two different concentrations of Nisin (500 or 1000 IU/g was not able to inhibit L. monocytogenes below the acceptable level for raw food (100 cells per g in minced meat and surimi of silver carp. But the number of bacteria reduces more in fish surimi as compared to the mince meal. Also, antilisterial activity of Nisin was reduced during the storage period. Conclusion: Inhibitory property of Nisin against L. monocytogenes in surimi significantly was higher than the minced (P<0.05. So it is possible the antilisterial properties of Nisin will increase by elimination of some enzymes during processing.

  9. Adenine phosphoribosyltransferase from Sulfolobus solfataricus is an enzyme with unusual kinetic properties and a crystal structure that suggests it evolved from a 6-oxopurine phosphoribosyltransferase.

    Science.gov (United States)

    Jensen, Kaj Frank; Hansen, Michael Riis; Jensen, Kristine Steen; Christoffersen, Stig; Poulsen, Jens-Christian Navarro; Mølgaard, Anne; Kadziola, Anders

    2015-04-14

    The adenine phosphoribosyltransferase (APRTase) encoded by the open reading frame SSO2342 of Sulfolobus solfataricus P2 was subjected to crystallographic, kinetic, and ligand binding analyses. The enzyme forms dimers in solution and in the crystals, and binds one molecule of the reactants 5-phosphoribosyl-α-1-pyrophosphate (PRPP) and adenine or the product adenosine monophosphate (AMP) or the inhibitor adenosine diphosphate (ADP) in each active site. The individual subunit adopts an overall structure that resembles a 6-oxopurine phosphoribosyltransferase (PRTase) more than known APRTases implying that APRT functionality in Crenarchaeotae has its evolutionary origin in this family of PRTases. Only the N-terminal two-thirds of the polypeptide chain folds as a traditional type I PRTase with a five-stranded β-sheet surrounded by helices. The C-terminal third adopts an unusual three-helix bundle structure that together with the nucleobase-binding loop undergoes a conformational change upon binding of adenine and phosphate resulting in a slight contraction of the active site. The inhibitor ADP binds like the product AMP with both the α- and β-phosphates occupying the 5'-phosphoribosyl binding site. The enzyme shows activity over a wide pH range, and the kinetic and ligand binding properties depend on both pH and the presence/absence of phosphate in the buffers. A slow hydrolysis of PRPP to ribose 5-phosphate and pyrophosphate, catalyzed by the enzyme, may be facilitated by elements in the C-terminal three-helix bundle part of the protein.

  10. Enzyme cofactors: Double-edged sword for catalysis

    Science.gov (United States)

    Ivanov, Ivaylo

    2013-01-01

    The metal cofactors responsible for the activity of CDK2 -- a representative member of the kinase superfamily of enzymes -- have now been shown to also have inhibitory effects during the catalytic cycle.

  11. Viewing the human microbiome through three-dimensional glasses: integrating structural and functional studies to better define the properties of myriad carbohydrate-active enzymes

    International Nuclear Information System (INIS)

    Turnbaugh, Peter J.; Henrissat, Bernard; Gordon, Jeffrey I.

    2010-01-01

    Metagenomics has unleashed a deluge of sequencing data describing the organismal, genetic, and transcriptional diversity of the human microbiome. To better understand the precise functions of the myriad proteins encoded by the microbiome, including carbohydrate-active enzymes, it will be critical to combine structural studies with functional analyses. Recent studies have provided an unprecedented view of the trillions of microbes associated with the human body. The human microbiome harbors tremendous diversity at multiple levels: the species that colonize each individual and each body habitat; the genes that are found in each organism’s genome; the expression of these genes and the interactions and activities of their protein products. The sources of this diversity are wide-ranging and reflect both environmental and host factors. A major challenge moving forward is defining the precise functions of members of various families of proteins represented in our microbiomes, including the highly diverse carbohydrate-active enzymes (CAZymes) involved in numerous biologically important chemical transformations, such as the degradation of complex dietary polysaccharides. Coupling metagenomic analyses to structural genomics initiatives and to biochemical and other functional assays of CAZymes will be essential for determining how these as well as other microbiome-encoded proteins operate to shape the properties of microbial communities and their human hosts

  12. Functional antioxidant and tyrosinase inhibitory properties of ...

    African Journals Online (AJOL)

    Jane

    2011-07-27

    Jul 27, 2011 ... (Miyu) had the highest phenolic content (9.99 mg of gallic acid equivalent/g). C. grandis ... and this compound too possesses good radical-scavenging activity. The ferrous-ion ..... leaves and rhizomes of ginger species.

  13. Allostery Is an Intrinsic Property of the Protease Domain of DegS Implications for Enzyme Function and Evolution

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Jungsan; Grant, Robert A.; Sauer, Robert T. (MIT)

    2010-12-02

    DegS is a periplasmic Escherichia coli protease, which functions as a trimer to catalyze the initial rate-limiting step in a proteolytic cascade that ultimately activates transcription of stress response genes in the cytoplasm. Each DegS subunit consists of a protease domain and a PDZ domain. During protein folding stress, DegS is allosterically activated by peptides exposed in misfolded outer membrane porins, which bind to the PDZ domain and stabilize the active protease. It is not known whether allostery is conferred by the PDZ domains or is an intrinsic feature of the trimeric protease domain. Here, we demonstrate that free DegS{sup {Delta}PDZ} equilibrates between active and inactive trimers with the latter species predominating. Substrate binding stabilizes active DegS{sup {Delta}PDZ} in a positively cooperative fashion. Mutations can also stabilize active DegS{sup {Delta}PDZ} and produce an enzyme that displays hyperbolic kinetics and degrades substrate with a maximal velocity within error of that for fully activated, intact DegS. Crystal structures of multiple DegS{sup {Delta}PDZ} variants, in functional and non-functional conformations, support a two-state model in which allosteric switching is mediated by changes in specific elements of tertiary structure in the context of an invariant trimeric base. Overall, our results indicate that protein substrates must bind sufficiently tightly and specifically to the functional conformation of DegS{sup {Delta}PDZ} to assist their own degradation. Thus, substrate binding alone may have regulated the activities of ancestral DegS trimers with subsequent fusion of the protease domain to a PDZ domain, resulting in ligand-mediated regulation.

  14. Comparisons of Soil Properties, Enzyme Activities and Microbial Communities in Heavy Metal Contaminated Bulk and Rhizosphere Soils of Robinia pseudoacacia L. in the Northern Foot of Qinling Mountain

    Directory of Open Access Journals (Sweden)

    Yurong Yang

    2017-11-01

    Full Text Available The toxic effects of heavy metal (HM contamination on plant metabolism and soil microorganisms have been emphasized recently; however, little is known about the differences in soil physical, chemical, and biological properties between bulk and rhizosphere soils contaminated with HMs in forest ecosystem. The present study was conducted to evaluate the rhizosphere effect on soil properties, enzyme activities and bacterial communities associated with Robinia pseudoacacia L. along a HM contamination gradient. Soil organic matter (SOM, available nitrogen (AN and phosphorus (AP contents were significantly higher in rhizosphere soil than those in bulk soil at HM contaminated sites (p < 0.05. Compared to bulk soil, activities of four soil enzymes indicative of C cycle (β-glucosidase, N cycle (protease, urease and P cycle (alkaline phosphatase in rhizosphere soil across all study sites increased by 47.5%, 64.1%, 52.9% and 103.8%, respectively. Quantitative PCR (qPCR and restriction fragment length polymorphism (RFLP were used to determine the relative abundance, composition and diversity of bacteria in both bulk and rhizosphere soils, respectively. The copy number of bacterial 16S rRNA gene in bulk soil was significantly lower than that in rhizosphere soil (p < 0.05, and it had significantly negative correlations with total/DTPA-extractable Pb concentrations (p < 0.01. Alphaproteobacteria, Gammaproteobacteria and Firmicutes were the most dominant groups of bacteria at different study sites. The bacterial diversity index of Species richness (S and Margalef (dMa were significantly higher in rhizosphere soil compared with those in bulk soil, although no difference could be found in Simpson index (D between bulk and rhizosphere soils (p > 0.05. Redundancy analysis (RDA results showed that soil pH, EC, SOM and total/DTPA-extractable Pb concentrations were the most important variables affecting relative abundance, composition and diversity of bacteria (p < 0

  15. Synthesis and GGCT Inhibitory Activity of N-Glutaryl-L-alanine Analogues.

    Science.gov (United States)

    Ii, Hiromi; Yoshiki, Tatsuhiro; Hoshiya, Naoyuki; Uenishi, Jun'ichi

    2016-01-01

    γ-Glutamylcyclotransferase (GGCT) is an important enzyme that cleaves γ-glutamyl-amino acid in the γ-glutamyl cycle to release 5-oxoproline and amino acid. Eighteen N-acyl-L-alanine analogues including eleven new compounds have been synthesized and examined for their inhibitory activity against recombinant human GGCT protein. Simple N-glutaryl-L-alanine was found to be the most potent inhibitor for GGCT. Other N-glutaryl-L-alanine analogues having methyl and dimethyl substituents at the 2-position were moderately effective, while N-(3R-aminoglutary)-L-alanine, the substrate having an (R)-amino group at the 3-position or N-(N-methyl-3-azaglutaryl)-L-alanine, the substrate having an N-methyl substituent on the 3-azaglutaryl carbon, in constract, exhibited excellent inhibition properties.

  16. A diterpenoid sugiol from Metasequoia glyptostroboides with α-glucosidase and tyrosinase inhibitory potential

    Directory of Open Access Journals (Sweden)

    Vivek K. Bajpai

    2014-08-01

    Full Text Available Nowadays use of plant derived natural compounds have become a topic of increasing interest in food and medicine industries due to their multitude of biological and therapeutic properties. In this study, a diterpenoid compound sugiol, isolated from Metasequoia glyptostroboides was evaluated for α–glucosidase and tyrosinase inhibitory efficacy in terms of its potent anti-diabetic and anti-melanogenesis potential, respectively. As a result, sugiol at the concentration range of (100-10,000 µg/mL and (20-500 µg/mL showed potent efficacy on inhibiting α-glucosidase and tyrosinase enzymes in vitro ranging from 12.34-63.47% and 28.22-67.43%, respectively. These findings confirm the therapeutic potential of diterpenoid compound sugiol from M. glyptostroboides as a novel candidate for using in food and medicine industry which may have practical potential to cure skin and diabetes mellitus type-2 related disorders.

  17. Influence of enzymatic hydrolysis and enzyme type on the nutritional and antioxidant properties of pumpkin meal hydrolysates.

    Science.gov (United States)

    Venuste, Muhamyankaka; Zhang, Xiaoming; Shoemaker, Charles F; Karangwa, Eric; Abbas, Shabbar; Kamdem, Patrick Eugene

    2013-04-30

    Nutritional and antioxidant properties of pumpkin meal and their hydrolysates prepared by hydrolysis with alcalase, flavourzyme, protamex or neutrase were evaluated. The hydrolysis process significantly increased protein content from 67.07% to 92.22%. All the essential amino acids met the Food and Agriculture Organization of United Nations/World Health Organization (WHO/FAO) suggested requirements for children and adults. The amino acid score (AAS) of meal was increased from 65.59 to 73.00 except for flavourzyme (62.97) and protamex (62.50). The Biological Value (BV) was increased from 53.18 to 83.44 except for protamex (40.97). However hydrolysis decreased the Essential Amino Acid/Total Amino Acid ratio (EAA/TAA) from 32.98% to 29.43%. Protein Efficiency Ratio (PER) was comparable to that of good quality protein (1.5) except for flavourzyme hydrolysate which had PER1 = 0.92, PER2 = 1.03, PER3 = 0.38. The in vitro protein digestibility (IVPD) increased from 71.32% to 77.96%. Antioxidant activity increased in a dose-dependent manner. At 10 mg mL(-1), the hydrolysates had increased 1,1-diphenyl-2-picrylhydrazy (DPPH) radical scavenging activities from 21.89% to 85.27%, the reducing power increased from Abs(700nm) 0.21 to 0.48. Metal (Iron) chelating ability was improved from 30.50% to 80.03% at 1 mg mL(-1). Hydrolysates also showed better capabilities to suppress or delay lipid peroxidation in a linoleic acid model system. Different proteases lead to different Degrees of Hydrolysis (DH), molecular weight (MW) distribution, amino acid composition and sequence, which influenced the nutritional properties and antioxidant activities of the hydrolysates. Alcalase was the most promising protease in production of pumpkin protein hydrolysates with improved nutritional quality, while flavourzyme was best in production of hydrolysates with improved antioxidative activity among various assays. These results showed that hydrolysates from by-products of pumpkin oil

  18. Chemical properties and hydrolytic enzyme activities for the characterisation of two-phase olive mill wastes composting.

    Science.gov (United States)

    Cayuela, M L; Mondini, C; Sánchez-Monedero, M A; Roig, A

    2008-07-01

    Two-phase olive mill waste (TPOMW) is a semisolid sludge generated during the extraction of olive oil by the two-phase centrifugation system. Among all the available disposal options, composting is gaining interest as a sustainable strategy to recycle TPOMW for agricultural purposes. The quality of compost for agronomical use depends on the degree of organic matter stabilization, but despite several studies on the topic, there is not a single method available which alone can give a certain indication of compost stability. In addition, information on the biological and biochemical properties, including the enzymatic activity (EA) of compost, is rare. The aim of this work was to investigate the suitability of some enzymatic activities (beta-glucosidase, arylsulphatase, acid-phosphatase, alkaline-phosphatase, urease and fluorescein diacetate hydrolysis (FDA)) as parameters to evaluate organic matter stability during the composting of TPOMW. These enzymatic indices were also compared to conventional stability indices. For this purpose two composting piles were prepared by mixing TPOMW with sheep manure and grape stalks in different proportions, with forced aeration and occasional turnings. The composting of TPOMW followed the common pattern reported previously for this kind of material with a reduction of 40-50% of organic matter, a gradual increase in pH, disappearance of phytotoxicity and formation of humic-like C. All EA increased during composting except acid-phosphatase. Significant correlations were found between EA and some important conventional stability indices indicating that EA can be a simple and reliable tool to determine the degree of stability of TPOMW composts.

  19. Controlled release and angiotensin-converting enzyme inhibition properties of an antihypertensive drug based on a perindopril erbumine-layered double hydroxide nanocomposite

    Directory of Open Access Journals (Sweden)

    Hussein Al Ali SH

    2012-04-01

    Full Text Available Samer Hasan Hussein Al Ali1, Mothanna Al-Qubaisi2, Mohd Zobir Hussein1,3, Maznah Ismail2,4, Zulkarnain Zainal1, Muhammad Nazrul Hakim51Department of Chemistry, Faculty of Science, 2Laboratory of Molecular Biomedicine, Institute of Bioscience, 3Advanced Materials and Nanotechnology Laboratory, Institute of Advanced Technology, 4Department of Nutrition and Dietetics, Faculty of Medicine and Health Science, 5Department of Biomedical Science, Faculty of Medicine and Health Science, Universiti Putra Malaysia, Serdang, Selangor, MalaysiaBackground: The intercalation of perindopril erbumine into Zn/Al-NO3-layered double hydroxide resulted in the formation of a host-guest type of material. By virtue of the ion-exchange properties of layered double hydroxide, perindopril erbumine was released in a sustained manner. Therefore, this intercalated material can be used as a controlled-release formulation.Results: Perindopril was intercalated into the interlayers and formed a well ordered, layered organic-inorganic nanocomposite. The basal spacing of the products was expanded to 21.7 Å and 19.9 Å by the ion-exchange and coprecipitation methods, respectively, in a bilayer and a monolayer arrangement, respectively. The release of perindopril from the nanocomposite synthesized by the coprecipitation method was slower than that of its counterpart synthesized by the ion-exchange method. The rate of release was governed by pseudo-second order kinetics. An in vitro antihypertensive assay showed that the intercalation process results in effectiveness similar to that of the antihypertensive properties of perindopril.Conclusion: Intercalated perindopril showed better thermal stability than its free counterpart. The resulting material showed sustained-release properties and can therefore be used as a controlled-release formulation.Keywords: perindopril erbumine, layered double hydroxides, ion-exchange, coprecipitation, sustained release, angiotensin-converting enzyme

  20. Electron paramagnetic resonance spin label titration: a novel method to investigate random and site-specific immobilization of enzymes onto polymeric membranes with different properties

    International Nuclear Information System (INIS)

    Butterfield, D. Allan; Colvin, Joshua; Liu Jiangling; Wang Jianquan; Bachas, Leonidas; Bhattacharrya, Dibakar

    2002-01-01

    The immobilization of biological molecules onto polymeric membranes to produce biofunctional membranes is used for selective catalysis, separation, analysis, and artificial organs. Normally, random immobilization of enzymes onto polymeric membranes leads to dramatic reduction in activity due to chemical reactions involved in enzyme immobilization, multiple-point binding, etc., and the extent of activity reduction is a function of membrane hydrophilicity (e.g. activity in cellulosic membrane >> polysulfone membrane). We have used molecular biology to effect site-specific immobilization of enzymes in a manner that orients the active site away from the polymeric membrane surface, thus resulting in higher enzyme activity that approaches that in solution and in increased stability of the enzyme relative to the enzyme in solution. A prediction of this site-specific method of enzyme immobilization, which in this study with subtilisin and organophosphorus hydrolase consists of a fusion tag genetically added to these enzymes and subsequent immobilization via the anti-tag antibody and membrane-bound protein A, is that the active site conformation will more closely resemble that of the enzyme in solution than is the case for random immobilization. This hypothesis was confirmed using a new electron paramagnetic resonance (EPR) spin label active site titration method that determines the amount of spin label bound to the active site of the immobilized enzyme. This value nearly perfectly matched the enzyme activity, and the results suggested: (a) a spectroscopic method for measuring activity and thus the extent of active enzyme immobilization in membrane, which may have advantages in cases where optical methods can not be used due to light scattering interference; (b) higher spin label incorporation (and hence activity) in enzymes that had been site-specifically immobilized versus random immobilization; (c) higher spin label incorporation in enzymes immobilized onto hydrophilic

  1. Cholinesterase inhibitory activity and structure elucidation of a new phytol derivative and a new cinnamic acid ester from Pycnanthus angolensis

    Directory of Open Access Journals (Sweden)

    Taiwo O. Elufioye

    Full Text Available ABSTRACT The leaves of Pycnanthus angolensis (Welw. Warb., Myristicaceae, are used as memory enhancer and anti-ageing in Nigerian ethnomedicine. This study aimed at evaluating the cholinesterase inhibitory property as well as isolates the bioactive compounds from the plant. The acetylcholinesterase and butyrylcholinesterase inhibitory potentials of extracts, fractions, and isolated compounds were evaluated by colorimetric and TLC bioautographic assay techniques. The extract inhibited both enzymes with activity increasing with purification, ethyl acetate fraction being most active fraction at 65.66 ± 1.06% and 49.38 ± 1.66% against acetylcholinesterase and butyrylcholinesterase, respectively while the supernatant had 77.44 ± 1.18 inhibition against acetylcholinesterase. Two new bioactive compounds, (2E, 18E-3,7,11,15,18-pentamethylhenicosa-2,18-dien-1-ol (named eluptol and [12-(4-hydroxy-3-methyl-oxo-cyclopenta-1,3-dien-1yl-11-methyl-dodecyl](E-3-(3,4-dimethylphenylprop-2-enoate (named omifoate A were isolated from the plant with IC50 of 22.26 µg/ml (AChE, 34.61 µg/ml (BuChE and 6.51 µg/ml (AChE, 9.07 µg/ml (BuChE respectively. The results showed that the plant has cholinesterase inhibitory activity which might be responsible for its memory enhancing action, thus justifying its inclusion in traditional memory enhancing preparations

  2. An appraisal of eighteen commonly consumed edible plants as functional food based on their antioxidant and starch hydrolase inhibitory activities.

    Science.gov (United States)

    Lee, Yian Hoon; Choo, Candy; Watawana, Mindani I; Jayawardena, Nilakshi; Waisundara, Viduranga Y

    2015-11-01

    Eighteen edible plants were assessed for their antioxidant potential based on oxygen radical absorbance capacity (ORAC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, total phenolics, vitamin C content and various lipophilic antioxidants. The inhibitory activities of the plant extracts against the enzymatic activities of α-amylase and α-glucosidase were also evaluated. The antioxidant and starch hydrolase activities of the plants varied widely across a single batch of analysis. The ORAC and DPPH radical scavenging EC50 values varied between 298 and 1984 Trolox equivalents g(-1) fresh weight and between 91 and 533 mg kg(-1) fresh weight, respectively. The total phenolics and vitamin C contents varied between 32 and 125 mg gallic acid equivalents g(-1) fresh weight and between 96 and 285 µg g(-1) fresh weight, respectively. All the plants contained neoxanthin, violaxanthin, and α- and β-carotene in varying amounts. Coccinia grandis, Asparagus racemosus, Costus speciosus, Amaranthus viridis and Annona muricata displayed the highest inhibitory activities against starch hydrolases. They were the most efficient against the breakdown of seven starches exposed to the two enzymes as well. Overall, the edible plants were observed to display a high antioxidant potential with starch hydrolase inhibitory properties, which were beneficial in their being recognized as functional food. © 2014 Society of Chemical Industry.

  3. Cardiac effects of r-79595 and its isomers (r-80122 and r-80123) in an acute heart-failure model - a new class of cardiotonic agents with highly selective phosphodiesterase-iii inhibitory properties

    NARCIS (Netherlands)

    SCHNEIDER, J; BECK, E; HEERS, C; CONRAD, C; DECOURCELLES, DD; WILFFERT, B; Peters, Thies

    1992-01-01

    R 79595 (N-cyclohexyl-N-methyl-2-[[[phenyl (1,2,3,5-tetrahydro-2 oxoimidazo [2,1-b]-quinazolin-7-yl) methylene] amin] oxy] acetamide) and its isomers represent a novel class of compounds with phosphodiesterase (PDE) inhibitory and cardiotonic (positive inotropic) actions. The cardiac effects of this

  4. Angiotensin I-converting enzyme inhibitor derived from cottonseed ...

    African Journals Online (AJOL)

    Six proteolytic enzymes, including alcalase, flavourzyme, trypsin, neutrase, papain and pepsin, were employed to hydrolyze cottonseed protein to produce the hydrolysates of Angiotensin I-converting enzyme (ACE) inhibitory activity. The result indicated that the cottonseed protein hydrolysate (CPH) produced by papain had ...

  5. The α-amylase and α-glucosidase inhibitory effects of Irish seaweed extracts.

    Science.gov (United States)

    Lordan, Sinéad; Smyth, Thomas J; Soler-Vila, Anna; Stanton, Catherine; Ross, R Paul

    2013-12-01

    To date, numerous studies have reported on the antidiabetic properties of various plant extracts through inhibition of carbohydrate-hydrolysing enzymes. The objective of this research was to evaluate extracts of seaweeds for α-amylase and α-glucosidase inhibitory effects. Cold water and ethanol extracts of 15 seaweeds were initially screened and from this, five brown seaweed species were chosen. The cold water and ethanol extracts of Ascophyllum nodosum had the strongest α-amylase inhibitory effect with IC50 values of 53.6 and 44.7 μg/ml, respectively. Moreover, the extracts of Fucus vesiculosus Linnaeus were found to be potent inhibitors of α-glucosidase with IC50 values of 0.32 and 0.49 μg/ml. The observed effects were associated with the phenolic content and antioxidant activity of the extracts, and the concentrations used were below cytotoxic levels. Overall, our findings suggest that brown seaweed extracts may limit the release of simple sugars from the gut and thereby alleviate postprandial hyperglycaemia. Copyright © 2013. Published by Elsevier Ltd.

  6. Antioxidant, ACE-Inhibitory and antibacterial activities of Kluyveromyces marxianus protein hydrolysates and their peptide fractions

    Directory of Open Access Journals (Sweden)

    Mahta Mirzaeia

    2016-07-01

    Full Text Available Background: There has been evidence that proteins are potentially excellent source of antioxidants, antihypertensive and antimicrobial peptides, and that enzymatic hydrolysis is an effective method to release these peptides from protein molecules. The functional properties of protein hydrolysates depends on the protein substrate, the specificity of the enzymes, the conditions used during proteolysis, degree of hydrolysis, and the nature of peptides released including molecular weight, amino acid composition, and hydrophobicity. Context and purpose of this study: The biomass of Kluyveromyces marxianus was considered as a source of ACE inhibitory, antioxidant and antimicrobial peptides. Results: Autolysis and enzymatic hydrolysis were completed respectively, after 96 h and 5 h. Overall, trypsin (18.52% DH and chymotrypsin (21.59% DH treatments were successful in releasing antioxidant and ACE inhibitory peptides. Autolysate sample (39.51% DH demonstrated poor antioxidant and ACE inhibitory activity compared to trypsin and chymotrypsin hydrolysates. The chymotrypsin 3-5 kDa (301.6±22.81 μM TE/mg protein and trypsin < 3 kDa (280.16±39.16 μM TE/mg protein permeate peptide fractions showed the highest DPPH radical scavenging activity. The trypsin <3 kDa permeate peptide fraction showed the highest ABTS radical scavenging (1691.1±48.68 μM TE/mg protein and ACE inhibitory (IC50=0.03±0.001 mg/mL activities. The fraction (MW=5-10 kD obtained after autolysis treatment showed antibacterial activity against St. aureus and Lis. monocytogenes in well diffusion screening. The minimum inhibitory concentration (MIC value was 13.3 mg/mLagainst St. aureus and Lis. monocytogenes calculated by turbidimetric assay and it showed bactericidal activity against St. aureus at 21.3 mg/mL protein concentration. Conclusions: Altogether, the results of this study reveal that K. marxianus proteins contain specific peptides in their sequences which can be released by

  7. Do detour tasks provide accurate assays of inhibitory control?

    Science.gov (United States)

    Whiteside, Mark A.; Laker, Philippa R.; Beardsworth, Christine E.

    2018-01-01

    Transparent Cylinder and Barrier tasks are used to purportedly assess inhibitory control in a variety of animals. However, we suspect that performances on these detour tasks are influenced by non-cognitive traits, which may result in inaccurate assays of inhibitory control. We therefore reared pheasants under standardized conditions and presented each bird with two sets of similar tasks commonly used to measure inhibitory control. We recorded the number of times subjects incorrectly attempted to access a reward through transparent barriers, and their latencies to solve each task. Such measures are commonly used to infer the differential expression of inhibitory control. We found little evidence that their performances were consistent across the two different Putative Inhibitory Control Tasks (PICTs). Improvements in performance across trials showed that pheasants learned the affordances of each specific task. Critically, prior experience of transparent tasks, either Barrier or Cylinder, also improved subsequent inhibitory control performance on a novel task, suggesting that they also learned the general properties of transparent obstacles. Individual measures of persistence, assayed in a third task, were positively related to their frequency of incorrect attempts to solve the transparent inhibitory control tasks. Neophobia, Sex and Body Condition had no influence on individual performance. Contrary to previous studies of primates, pheasants with poor performance on PICTs had a wider dietary breadth assayed using a free-choice task. Our results demonstrate that in systems or taxa where prior experience and differences in development cannot be accounted for, individual differences in performance on commonly used detour-dependent PICTS may reveal more about an individual's prior experience of transparent objects, or their motivation to acquire food, than providing a reliable measure of their inhibitory control. PMID:29593115

  8. INHIBITORY EFFECT OF SALVIA SCLAREA

    African Journals Online (AJOL)

    rakoe

    2011-11-02

    Nov 2, 2011 ... This study demonstrated anti-herpes simplex virus (HSV) activity of lavender, sage and ... Green monkey kidney cells were protected from HSV-2 infection by ... The highest inhibitory effect against HSV-2 was observed after treatment ..... some nuclear-replicating eukaryotic DNA viruses with large genomes.

  9. Inhibitory control in childhood stuttering

    NARCIS (Netherlands)

    Eggers, K.; de Nil, L.; Van den Bergh, B.R.H.

    2013-01-01

    Purpose The purpose of this study was to investigate whether previously reported parental questionnaire-based differences in inhibitory control (IC; Eggers, De Nil, & Van den Bergh, 2010) would be supported by direct measurement of IC using a computer task. Method Participants were 30 children who

  10. Somatostatin-expressing inhibitory interneurons in cortical circuits

    Directory of Open Access Journals (Sweden)

    Iryna Yavorska

    2016-09-01

    Full Text Available Cortical inhibitory neurons exhibit remarkable diversity in their morphology, connectivity, and synaptic properties. Here, we review the function of somatostatin-expressing (SOM inhibitory interneurons, focusing largely on sensory cortex. SOM neurons also comprise a number of subpopulations that can be distinguished by their morphology, input and output connectivity, laminar location, firing properties, and expression of molecular markers. Several of these classes of SOM neurons show unique dynamics and characteristics, such as facilitating synapses, specific axonal projections, intralaminar input, and top-down modulation, which suggest possible computational roles. SOM cells can be differentially modulated by behavioral state depending on their class, sensory system, and behavioral paradigm. The functional effects of such modulation have been studied with optogenetic manipulation of SOM cells, which produces effects on learning and memory, task performance, and the integration of cortical activity. Different classes of SOM cells participate in distinct disinhibitory circuits with different inhibitory partners and in different cortical layers. Through these disinhibitory circuits, SOM cells help encode the behavioral relevance of sensory stimuli by regulating the activity of cortical neurons based on subcortical and intracortical modulatory input. Associative learning leads to long-term changes in the strength of connectivity of SOM cells with other neurons, often influencing the strength of inhibitory input they receive. Thus despite their heterogeneity and variability across cortical areas, current evidence shows that SOM neurons perform unique neural computations, forming not only distinct molecular but also functional subclasses of cortical inhibitory interneurons.

  11. PROCESS FOR DUST-FREE ENZYME MANUFACTURE

    NARCIS (Netherlands)

    Andela, C.; Feijen, Jan; Dillissen, Marc

    1994-01-01

    New enzyme granules are provided with improved properties. The granules are based on core particles having a good pore size and pore size distribution to allow an enzyme solution to enter into the particle. Accordingly, the core material comprises the enzyme in liquid form, thus eliminating the

  12. Impulsivity: A deficiency of inhibitory control?

    NARCIS (Netherlands)

    Lansbergen, M.M.

    2007-01-01

    Impulsivity has been defined as acting without thinking. Impulsivity can be quantified by impulsivity questionnaires, but also by behavioral paradigms which tax inhibitory control. Previous research has repeatedly demonstrated deficient inhibitory control in psychopathological samples characterized

  13. Enzyme Mimics: Advances and Applications.

    Science.gov (United States)

    Kuah, Evelyn; Toh, Seraphina; Yee, Jessica; Ma, Qian; Gao, Zhiqiang

    2016-06-13

    Enzyme mimics or artificial enzymes are a class of catalysts that have been actively pursued for decades and have heralded much interest as potentially viable alternatives to natural enzymes. Aside from having catalytic activities similar to their natural counterparts, enzyme mimics have the desired advantages of tunable structures and catalytic efficiencies, excellent tolerance to experimental conditions, lower cost, and purely synthetic routes to their preparation. Although still in the midst of development, impressive advances have already been made. Enzyme mimics have shown immense potential in the catalysis of a wide range of chemical and biological reactions, the development of chemical and biological sensing and anti-biofouling systems, and the production of pharmaceuticals and clean fuels. This Review concerns the development of various types of enzyme mimics, namely polymeric and dendrimeric, supramolecular, nanoparticulate and proteinic enzyme mimics, with an emphasis on their synthesis, catalytic properties and technical applications. It provides an introduction to enzyme mimics and a comprehensive summary of the advances and current standings of their applications, and seeks to inspire researchers to perfect the design and synthesis of enzyme mimics and to tailor their functionality for a much wider range of applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Tyrosinase inhibitory components from Aloe vera and their antiviral activity.

    Science.gov (United States)

    Kim, Jang Hoon; Yoon, Ju-Yeon; Yang, Seo Young; Choi, Seung-Kook; Kwon, Sun Jung; Cho, In Sook; Jeong, Min Hee; Ho Kim, Young; Choi, Gug Seoun

    2017-12-01

    A new compound, 9-dihydroxyl-2'-O-(Z)-cinnamoyl-7-methoxy-aloesin (1), and eight known compounds (2-9) were isolated from Aloe vera. Their structures were elucidated using 1D/2D nuclear magnetic resonance and mass spectra. Compound 9 exhibited reversible competitive inhibitory activity against the enzyme tyrosinase, with an IC 50 value of 9.8 ± 0.9 µM. A molecular simulation revealed that compound 9 interacts via hydrogen bonding with residues His244, Thr261, and Val283 of tyrosinase. Additionally, compounds 3 and 7 were shown by half-leaf assays to exhibit inhibitory activity towards Pepper mild mottle virus.

  15. Biomedical Applications of Enzymes From Marine Actinobacteria.

    Science.gov (United States)

    Kamala, K; Sivaperumal, P

    Marine microbial enzyme technologies have progressed significantly in the last few decades for different applications. Among the various microorganisms, marine actinobacterial enzymes have significant active properties, which could allow them to be biocatalysts with tremendous bioactive metabolites. Moreover, marine actinobacteria have been considered as biofactories, since their enzymes fulfill biomedical and industrial needs. In this chapter, the marine actinobacteria and their enzymes' uses in biological activities and biomedical applications are described. © 2017 Elsevier Inc. All rights reserved.

  16. Photoreactivating enzyme from Escherichia coli

    International Nuclear Information System (INIS)

    Snapka, R.M.; Fuselier, C.O.

    1977-01-01

    Escherichia coli photoreactivating enzyme (PRE) has been purified in large amounts from an E.coli strain lysogenic for a defective lambda bacteriophage carrying the phr gene. The resulting enzyme had a pH optimum of 7.2 and an ionic strength optimum of 0.18. It consisted of an apoprotein and cofactor, both of which were necessary for catalytic activity. The apoprotein had a monomer molecular weight of 35,200 and showed stable aggregates under denaturing conditions. The amino acid analysis of the E.coli enzyme was very similar to that of the photoreactivating enzyme from orchid seedlings (Cattelya aurantiaca). Both had arginine at the amino terminus. The cofactor, like the holoenzyme, showed absorption, magnetic circular dichroism, and emission properties indicative of an adenine moiety. Although the isolated enzyme had an action spectrum which peaked at about 360 nm, neither the cofactor, apoenzyme nor holoenzyme showed any detectable absorption between 300 and 400 nm. (author)

  17. Photoreactivating enzyme from Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Snapka, R M; Fuselier, C O [California Univ., Irvine (USA)

    1977-05-01

    Escherichia coli photoreactivating enzyme (PRE) has been purified in large amounts from an E.coli strain lysogenic for a defective lambda bacteriophage carrying the phr gene. The resulting enzyme had a pH optimum of 7.2 and an ionic strength optimum of 0.18. It consisted of an apoprotein and cofactor, both of which were necessary for catalytic activity. The apoprotein had a monomer molecular weight of 35,200 and showed stable aggregates under denaturing conditions. The amino acid analysis of the E.coli enzyme was very similar to that of the photoreactivating enzyme from orchid seedlings (Cattelya aurantiaca). Both had arginine at the amino terminus. The cofactor, like the holoenzyme, showed absorption, magnetic circular dichroism, and emission properties indicative of an adenine moiety. Although the isolated enzyme had an action spectrum which peaked at about 360 nm, neither the cofactor, apoenzyme nor holoenzyme showed any detectable absorption between 300 and 400 nm.

  18. Use of Protease and Lipase Enzymes by Different Methods to Accelerate Kaşar Cheese Ripening 1. The Effect on Cheese Physical and Chemical Properties (Turkish with English Abstract

    Directory of Open Access Journals (Sweden)

    2015-02-01

    Full Text Available In this study, pasteurized cow milk was used for Kaşar cheese processing. One lipase (Palatase M, one protease (Neutrase, and combination of both enzymes were added to milk which was processed into cheese. Three different enzymes with the levels (based on raw milk amount of 0.0001% Palatese M. 0.004% Neutrase and 0.0001% Palatase M + 0.004% Neutrase were evaluated for physical and chemical properties at 2nd, 30th, 60th and 90th day of the ripening periods. Enzyme added cheese samples were compared with the Control-I (from fresh milk and Control-II (from pasteurized and starter added cheese samples. The 1% starter composed of Lactococcus lactis and Streptococcus cremoris (1:1 was added into the milk. Experiment was set up according to random block design with factorial arrangement, and the analysis were carried out in duplicate. Cheese yields of all the cheese samples produced with the enzyme addition were lower than the control groups. But, 0.0001% Palatase M(Mik-L added with microencapsulation technique gave the higher cheese yield which is closer to the control groups. With the enzyme addition, dry-matter; fat, protein, salt, acidity, fat in dry-matter, salt in dry-matter and the ripening degree; with the ripening period dry-matter, fat, protein, ash, salt, acidity, salt in dry-matter and the ripening degree gave statistically (P<0.01 significant results. It was determined that the interaction of enzyme addition x ripened period had an significant influence on dry-matter, fat, protein, acidity, fat in dry-matter and ripening degree of the cheeses produced in this research (P<0.01. The best ripened condition was achieved by adding lipase+protease enzymes together into milk with direct technique (Di-L+P. The same ripened state in the cheeses was reached in 30-60 days ripened period with the direct incorporation of lipase + protease enzymes together (Di+L+P or protease only (Di-P, but in 90 days in control groups containing no enzymes.

  19. The Diversity of Cortical Inhibitory Synapses

    Directory of Open Access Journals (Sweden)

    Yoshiyuki eKubota

    2016-04-01

    Full Text Available The most typical and well known inhibitory action in the cortical microcircuit is a strong inhibition on the target neuron by axo-somatic synapses. However, it has become clear that synaptic inhibition in the cortex is much more diverse and complicated. Firstly, at least ten or more inhibitory non-pyramidal cell subtypes engage in diverse inhibitory functions to produce the elaborate activity characteristic of the different cortical states. Each distinct non-pyramidal cell subtype has its own independent inhibitory function. Secondly, the inhibitory synapses innervate different neuronal domains, such as axons, spines, dendrites and soma, and their IPSP size is not uniform. Thus cortical inhibition is highly complex, with a wide variety of anatomical and physiological modes. Moreover, the functional significance of the various inhibitory synapse innervation styles and their unique structural dynamic behaviors differ from those of excitatory synapses. In this review, we summarize our current understanding of the inhibitory mechanisms of the cortical microcircuit.

  20. Cyclooxygenase-2 inhibitory and antioxidant compounds from the truffle Elaphomyces granulatus

    Science.gov (United States)

    Rita Stanikunaite; Shabana I. Khan; James M. Trappe; Samir A. Ross

    2009-01-01

    The ethanol extract of fruiting bodies of Elaphomyces granulatus, a truffle-like fungus, was evaluated for cyclooxygenase-2 (COX-2) enzyme inhibitory and antioxidant activities. Inhibition of COX-2 activity was evaluated in mouse macrophages (RAW 264.7). The extract of E. granulatus caused a 68% inhibition of COX-2 activity at...

  1. Properties of latent and thiol-activated rat hepatic 3-hydroxy-3-methylglutaryl-coenzyme A reductase and regulation of enzyme activity.

    Science.gov (United States)

    Dotan, I; Shechter, I

    1983-10-15

    The effect of the thiols glutathione (GSH), dithiothreitol (DTT), and dithioerythritol (DTE) on the conversion of an inactive, latent form (El) of rat liver 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase, EC 1.1.1.34) to a catalyticaly active form (Ea) is examined. Latent hepatic microsomal HMG-CoA reductase is activated to a similar degree of activation by DTT and DTE and to a lower extent by GSH. All three thiols affect both Km and Vmax values of the enzyme toward HMG-CoA and NADPH. Studies of the effect of DTT on the affinity binding of HMG-CoA reductase to agarose-hexane-HMG-CoA (AG-HMG-CoA) resin shows that thiols are necessary for the binding of the enzyme to the resin. Removal of DTT from AG-HMG-CoA-bound soluble Ea (active enzyme) does not cause dissociation of the enzyme from the resin at low salt concentrations. Substitution of DTT by NADPH does not promote binding of soluble El (latent enzyme) to AG-HMG-CoA. The enzymatic activity of Ea in the presence of DTT and GSH indicates that these thiols compete for the same binding site on the enzyme. Diethylene glycol disulfide (ESSE) and glutathione disulfide (GSSG) inhibit the activity of Ea. ESSE is more effective for the inhibition of Ea than GSSG, causing a higher degree of maximal inhibition and affecting the enzymatic activity at lower concentrations. A method is described for the rapid conversion of soluble purified Ea to El using gel-filtration chromatography on Bio-Gel P-4 columns. These combined results point to the importance of the thiol/disulfide ratio for the modulation of hepatic HMG-CoA reductase activity.

  2. Degree of synchronization modulated by inhibitory neurons in clustered excitatory-inhibitory recurrent networks

    Science.gov (United States)

    Li, Huiyan; Sun, Xiaojuan; Xiao, Jinghua

    2018-01-01

    An excitatory-inhibitory recurrent neuronal network is established to numerically study the effect of inhibitory neurons on the synchronization degree of neuronal systems. The obtained results show that, with the number of inhibitory neurons and the coupling strength from an inhibitory neuron to an excitatory neuron increasing, inhibitory neurons can not only reduce the synchronization degree when the synchronization degree of the excitatory population is initially higher, but also enhance it when it is initially lower. Meanwhile, inhibitory neurons could also help the neuronal networks to maintain moderate synchronized states. In this paper, we call this effect as modulation effect of inhibitory neurons. With the obtained results, it is further revealed that the ratio of excitatory neurons to inhibitory neurons being nearly 4 : 1 is an economic and affordable choice for inhibitory neurons to realize this modulation effect.

  3. Lipolytic enzymes LipA and LipB from Bacillus subtilis differ in regulation of gene expression, biochemical properties, and three-dimensional structure

    NARCIS (Netherlands)

    Eggert, Thorsten; Pouderoyen, Gertie van; Dijkstra, Bauke W.; Jaeger, Karl-Erich

    2001-01-01

    Bacillus subtilis secretes the lipolytic enzymes LipA and LipB. We show here that they are differentially expressed depending on the composition of the growth medium: LipA is produced in rich and in minimal medium, whereas LipB is present only in rich medium. A comparison of biochemical

  4. Critical evaluation of the use of bioinformatics as a theoretical tool to find high-potential sources of ACE inhibitory peptides

    NARCIS (Netherlands)

    Vercruysse, L.; Smagghe, G.; Bent, van der A.; Amerongen, van A.; Ongenaert, M.; Camp, van J.

    2009-01-01

    A bioinformatics analysis to screen for high-potential sources of angiotensin converting enzyme (ACE) inhibitory peptides was conducted in the area of insect muscle proteins. Vertebrate muscle proteins are reported as good sources of ACE inhibitory peptides, while the research on invertebrate muscle

  5. Plants from Brazilian Cerrado with potent tyrosinase inhibitory activity.

    Directory of Open Access Journals (Sweden)

    Paula Monteiro Souza

    Full Text Available The increased amount of melanin leads to skin disorders such as age spots, freckles, melasma and malignant melanoma. Tyrosinase is known to be the key enzyme in melanin production. Plants and their extracts are inexpensive and rich resources of active compounds that can be utilized to inhibit tyrosinase as well as can be used for the treatment of dermatological disorders associated with melanin hyperpigmentation. Using in vitro tyrosinase inhibitory activity assay, extracts from 13 plant species from Brazilian Cerrado were evaluated. The results showed that Pouteria torta and Eugenia dysenterica extracts presented potent in vitro tyrosinase inhibition compared to positive control kojic acid. Ethanol extract of Eugenia dysenterica leaves showed significant (p<0.05 tyrosinase inhibitory activity exhibiting the IC₅₀ value of 11.88 µg/mL, compared to kojic acid (IC₅₀ value of 13.14 µg/mL. Pouteria torta aqueous extract leaves also showed significant inhibitory activity with IC₅₀ value of 30.01 µg/mL. These results indicate that Pouteria torta and Eugenia dysenterica extracts and their isolated constituents are promising agents for skin-whitening or antimelanogenesis formulations.

  6. Enzyme detection by microfluidics

    DEFF Research Database (Denmark)

    2013-01-01

    Microfluidic-implemented methods of detecting an enzyme, in particular a DNA-modifying enzyme, are provided, as well as methods for detecting a cell, or a microorganism expressing said enzyme. The enzyme is detected by providing a nucleic acid substrate, which is specifically targeted...... by that enzyme...

  7. Length and coverage of inhibitory decision rules

    KAUST Repository

    Alsolami, Fawaz

    2012-01-01

    Authors present algorithms for optimization of inhibitory rules relative to the length and coverage. Inhibitory rules have a relation "attribute ≠ value" on the right-hand side. The considered algorithms are based on extensions of dynamic programming. Paper contains also comparison of length and coverage of inhibitory rules constructed by a greedy algorithm and by the dynamic programming algorithm. © 2012 Springer-Verlag.

  8. Monetary rewards modulate inhibitory control

    Directory of Open Access Journals (Sweden)

    Paula Marcela Herrera

    2014-05-01

    Full Text Available The ability to override a dominant response, often referred to as behavioural inhibiton, is considered a key element of executive cognition. Poor behavioural inhibition is a defining characteristic of several neurological and psychiatric populations. Recently, there has been increasing interest in the motivational dimension of behavioural inhibition, with some experiments incorporating emotional contingencies in classical inhibitory paradigms such as the Go/Nogo and Stop Signal Tasks. Several studies have reported a positive modulatory effect of reward on the performance of such tasks in pathological conditions such as substance abuse, pathological gambling, and ADHD. However, experiments that directly investigate the modulatory effects of reward magnitudes on the performance of inhibitory paradigms are rare and consequently, little is known about the finer grained relationship between motivation and self-control. Here, we probed the effect of reward and reward magnitude on behavioural inhibition using two modified version of the widely used Stop Signal Task. The first task compared no reward with reward, whilst the other compared two different reward magnitudes. The reward magnitude effect was confirmed by the second study, whereas it was less compelling in the first study, possibly due to the effect of having no reward in some conditions. In addition, our results showed a kick start effect over global performance measures. More specifically, there was a long lasting improvement in performance throughout the task, when participants received the highest reward magnitudes at the beginning of the protocol. These results demonstrate that individuals’ behavioural inhibition capacities are dynamic not static because they are modulated by the reward magnitude and initial reward history of the task at hand.

  9. Versatility of 7-Substituted Coumarin Molecules as Antimycobacterial Agents, Neuronal Enzyme Inhibitors and Neuroprotective Agents

    Directory of Open Access Journals (Sweden)

    Erika Kapp

    2017-09-01

    Full Text Available A medium-throughput screen using Mycobacterium tuberculosis H37Rv was employed to screen an in-house library of structurally diverse compounds for antimycobacterial activity. In this initial screen, eleven 7-substituted coumarin derivatives with confirmed monoamine oxidase-B and cholinesterase inhibitory activities, demonstrated growth inhibition of more than 50% at 50 µM. This prompted further exploration of all the 7-substituted coumarins in our library. Four compounds showed promising MIC99 values of 8.31–29.70 µM and 44.15–57.17 µM on M. tuberculosis H37Rv in independent assays using GAST-Fe and 7H9+OADC media, respectively. These compounds were found to bind to albumin, which may explain the variations in MIC between the two assays. Preliminary data showed that they were able to maintain their activity in fluoroquinolone resistant mycobacteria. Structure-activity relationships indicated that structural modification on position 4 and/or 7 of the coumarin scaffold could direct the selectivity towards either the inhibition of neuronal enzymes or the antimycobacterial effect. Moderate cytotoxicities were observed for these compounds and slight selectivity towards mycobacteria was indicated. Further neuroprotective assays showed significant neuroprotection for selected compounds irrespective of their neuronal enzyme inhibitory properties. These coumarin molecules are thus interesting lead compounds that may provide insight into the design of new antimicrobacterial and neuroprotective agents.

  10. Effects of inorganic and organic amendment on soil chemical properties, enzyme activities, microbial community and soil quality in yellow clayey soil.

    Directory of Open Access Journals (Sweden)

    Zhanjun Liu

    Full Text Available Understanding the effects of external organic and inorganic components on soil fertility and quality is essential for improving low-yielding soils. We conducted a field study over two consecutive rice growing seasons to investigate the effect of applying chemical fertilizer (NPK, NPK plus green manure (NPKG, NPK plus pig manure (NPKM, and NPK plus straw (NPKS on the soil nutrient status, enzyme activities involved in C, N, P, and S cycling, microbial community and rice yields of yellow clayey soil. Results showed that the fertilized treatments significantly improved rice yields over the first three experimental seasons. Compared with the NPK treatment, organic amendments produced more favorable effects on soil productivity. Notably, the NPKM treatment exhibited the highest levels of nutrient availability, microbial biomass carbon (MBC, activities of most enzymes and the microbial community. This resulted in the highest soil quality index (SQI and rice yield, indicating better soil fertility and quality. Significant differences in enzyme activities and the microbial community were observed among the treatments, and redundancy analysis showed that MBC and available N were the key determinants affecting the soil enzyme activities and microbial community. The SQI score of the non-fertilized control (0.72 was comparable to that of the NPK (0.77, NPKG (0.81 and NPKS (0.79 treatments but significantly lower compared with NPKM (0.85. The significant correlation between rice yield and SQI suggests that SQI can be a useful to quantify soil quality changes caused by different agricultural management practices. The results indicate that application of NPK plus pig manure is the preferred option to enhance SOC accumulation, improve soil fertility and quality, and increase rice yield in yellow clayey soil.

  11. Effects of soil properties and management on the activity of soil organic matter transforming enzymes and the quantification of soil-bound and free activity

    Czech Academy of Sciences Publication Activity Database

    Štursová, Martina; Baldrian, Petr

    2011-01-01

    Roč. 338, 1-2 (2011), s. 99-110 ISSN 0032-079X R&D Projects: GA ČR GA526/08/0751; GA MŠk LC06066; GA MZe QH72216 Institutional research plan: CEZ:AV0Z50200510 Keywords : Extracellular enzymes * Decomposition * Lignocellulose Subject RIV: EE - Microbiology, Virology Impact factor: 2.733, year: 2011

  12. Phosphoribosylpyrophosphate synthetase of Escherichia coli. Properties of the purified enzyme and primary structure of the prs gene

    DEFF Research Database (Denmark)

    Hove-Jensen, Bjarne; Harlow, Kenneth W.; King, Cheryl J.

    1986-01-01

    Phosphoribosylpyrophosphate (P-Rib-PP) synthetase of Escherichia coli has been purified to near homogeneity from a strain harboring the prs gene, encoding P-Rib-PP synthetase, on a multicopy plasmid. Analysis of the enzyme showed that it required inorganic phosphate for activity and for stability...... the UAA translation stop codon, within a Thy-rich region following an inverted repeat sequence, indicative of an rho-independent transcription terminator....

  13. Elevated Liver Enzymes

    Science.gov (United States)

    Symptoms Elevated liver enzymes By Mayo Clinic Staff Elevated liver enzymes may indicate inflammation or damage to cells in the liver. Inflamed or ... than normal amounts of certain chemicals, including liver enzymes, into the bloodstream, which can result in elevated ...

  14. Purification and properties of phosphoribosyl-diphosphate synthetase from Bacillus subtilis

    DEFF Research Database (Denmark)

    Arnvig, Kirsten; Hove-Jensen, Bjarne; Switzer, Robert L.

    1990-01-01

    enzyme required Mg2+ and inorganic phosphate for activity; Mn2+ supported only 30% the activity seen with Mg2+. Michaelis constants for ATP and ribose 5-phosphate (Rib5P) were 0.66 mM and 0.48 mM, respectively. Of several end products tested, only ADP was strongly inhibitory; GDP was a weak inhibitor....... ADP inhibition displayed homotropic cooperativity and was enhanced by increasing saturation of the enzyme with ATP. These observations strongly suggest a specific allosteric site for ADP binding. A comparison of physical and kinetic properties of bacterial and mammalian PPRibP synthetases is presented....

  15. The inhibitory effect of metals and other ions on acid phosphatase activity from Vigna aconitifolia seeds.

    Science.gov (United States)

    Srivastava, Pramod Kumar; Anand, Asha

    2015-01-01

    Sensitivity of acid phosphatase from Vigna aconitifolia seeds to metal ions, fluoride, and phosphate was examined. All the effectors had different degree of inhibitory effect on the enzyme. Among metal ions, molybdate and ferric ion were observed to be most potent inhibitors and both exhibited mixed type of inhibition. Acid phosphatase activity was inhibited by Cu2+ in a noncompetitive manner. Zn and Mn showed mild inhibition on the enzyme activity. Inhibition kinetics analysis explored molybdate as a potent inhibitor for acid phosphatase in comparison with other effectors used in this study. Fluoride was the next most strong inhibitor for the enzyme activity, and caused a mixed type of inhibition. Phosphate inhibited the enzyme competitively, which demonstrates that inhibition due to phosphate is one of the regulatory factors for enzyme activity.

  16. Physicochemical properties of the modeled structure of astacin metalloprotease moulting enzyme NAS-36 and mapping the druggable allosteric space of Heamonchus contortus, Brugia malayi and Ceanorhabditis elegans via molecular dynamics simulation.

    Science.gov (United States)

    Sharma, Om Prakash; Agrawal, Sonali; Kumar, M Suresh

    2013-12-01

    Nematodes represent the second largest phylum in the animal kingdom. It is the most abundant species (500,000) in the planet. It causes chronic, debilitating infections worldwide such as ascariasis, trichuriasis, hookworm, enterobiasis, strongyloidiasis, filariasis and trichinosis, among others. Molecular modeling tools can play an important role in the identification and structural investigation of molecular targets that can act as a vital candidate against filariasis. In this study, sequence analysis of NAS-36 from H. contortus (Heamonchus contortus), B. malayi (Brugia malayi) and C. elegans (Ceanorhabditis elegans) has been performed, in order to identify the conserved residues. Tertiary structure was developed for an insight into the molecular structure of the enzyme. Molecular Dynamics Simulation (MDS) studies have been carried out to analyze the stability and the physical properties of the proposed enzyme models in the H. contortus, B. malayi and C. elegans. Moreover, the drug binding sites have been mapped for inhibiting the function of NAS-36 enzyme. The molecular identity of this protease could eventually demonstrate how ex-sheathment is regulated, as well as provide a potential target of anthelmintics for the prevention of nematode infections.

  17. Lactoferricin B-derived peptides with inhibitory effects on ECE-dependent vasoconstriction.

    Science.gov (United States)

    Fernández-Musoles, Ricardo; López-Díez, José Javier; Torregrosa, Germán; Vallés, Salvador; Alborch, Enrique; Manzanares, Paloma; Salom, Juan B

    2010-10-01

    Endothelin-converting enzyme (ECE), a key peptidase in the endothelin (ET) system, cleaves inactive big ET-1 to produce active ET-1, which binds to ET(A) receptors to exert its vasoconstrictor and pressor effects. ECE inhibition could be beneficial in the treatment of hypertension. In this study, a set of eight lactoferricin B (LfcinB)-derived peptides, previously characterized in our laboratory as angiotensin-converting enzyme (ACE) inhibitory peptides, was examined for their inhibitory effects on ECE. In vitro inhibitory effects on ECE activity were assessed using both the synthetic fluorogenic peptide substrate V (FPS V) and the natural substrate big ET-1. To study vasoactive effects, an ex vivo functional assay was developed using isolated rabbit carotid artery segments. With FPS V, only four LfcinB-derived peptides induced inhibition of ECE activity, whereas the eight peptides showed ECE inhibitory effects with big ET-1 as substrate. Regarding the ex vivo assays, six LfcinB-derived peptides showed inhibition of big ET-1-induced, ECE-dependent vasoconstriction. A positive correlation between the inhibitory effects of LfcinB-derived peptides on ECE activity when using big ET-1 and the inhibitory effects on ECE-dependent vasoconstriction was shown. ECE-independent vasoconstriction induced by ET-1 was not affected, thus discarding effects of LfcinB-derived peptides on ET(A) receptors or intracellular signal transduction mechanisms. In conclusion, a combined in vitro and ex vivo method to assess the effects of potentially antihypertensive peptides on the ET system has been developed and applied to show the inhibitory effects on ECE-dependent vasoconstriction of six LfcinB-derived peptides, five of which were dual vasopeptidase (ACE/ECE) inhibitors. Copyright © 2010 Elsevier Inc. All rights reserved.

  18. Plasticity of cortical excitatory-inhibitory balance.

    Science.gov (United States)

    Froemke, Robert C

    2015-07-08

    Synapses are highly plastic and are modified by changes in patterns of neural activity or sensory experience. Plasticity of cortical excitatory synapses is thought to be important for learning and memory, leading to alterations in sensory representations and cognitive maps. However, these changes must be coordinated across other synapses within local circuits to preserve neural coding schemes and the organization of excitatory and inhibitory inputs, i.e., excitatory-inhibitory balance. Recent studies indicate that inhibitory synapses are also plastic and are controlled directly by a large number of neuromodulators, particularly during episodes of learning. Many modulators transiently alter excitatory-inhibitory balance by decreasing inhibition, and thus disinhibition has emerged as a major mechanism by which neuromodulation might enable long-term synaptic modifications naturally. This review examines the relationships between neuromodulation and synaptic plasticity, focusing on the induction of long-term changes that collectively enhance cortical excitatory-inhibitory balance for improving perception and behavior.

  19. α-/β-Glucosidase and α-Amylase Inhibitory Activities of Roselle (Hibiscus sabdariffa L. Ethanol Extract

    Directory of Open Access Journals (Sweden)

    Marisca Evalina Gondokesumo

    2017-03-01

    Full Text Available Background: Diabetes mellitus is a metabolic disease, characterized by hyperglycemia due to disturbance in both insulin secretion and function. One of theurapeutic approaches is to reduce blood glucose levels by inhbiting α-/β-glucosidase and α-amylase involved in carbohydrate digestion. Thus, inhibition of these enzymes play important role in the treatment of diabetes mellitus. Roselle (Hibiscus sabdariffa L. has been known to have several medicinal properties and potency as an antidiabetics agents. This reseacrh aimed to observe antidiabetic properties of roselle ethanol extract (REE towards α-glucosidase, β-glucosidase and α-amylase. Materials and Methods: REE was done with maceration technique using diluent of 70% ethanol. Antidiabetic properties were measured by inhibitory activity of α-amylase, α-glucosidase and β-glucosidase. Results: REE was able to inhibit α-/β-glucosidase and α-amylase in the highest concentration with inhibition percentage of 72.68, 47.34 and 73.08% respectively, and were comparable with Acarbose of 81.49, 50.97, 73.08%. The median inhibitory concentration (IC50 of α-/β-glucosidase and α-amylase of REE were 15.81, 41.77, 18.09 μg/mL respectively, and Acarbose were 9.45, 22.57, 3.64 μg/mL respectively. Conclusions: REE inhibits α-/β-glucosidase and α-amylase. Keywords: Roselle, Acarbose, α-glucosidase, β-glucosidase, α-amylase, antidiabetic

  20. Purification and characterization of angiotensin-1 converting enzyme

    African Journals Online (AJOL)

    The Nemopilema nomurai hydrolysate was produced by the reaction of papain, and an angiotensin-Ι converting enzyme (ACE)-inhibitory peptide was purified by ... The infrared (IR), proton nuclear magnetic resonance spectroscopy (1H NMR), carbon nuclear magnetic resonance (13C NMR) and mass spectrometry (MS) ...

  1. In Vitro Studies on the Antioxidant Property and Inhibition of α-Amylase, α-Glucosidase, and Angiotensin I-Converting Enzyme by Polyphenol-Rich Extracts from Cocoa (Theobroma cacao) Bean.

    Science.gov (United States)

    Oboh, Ganiyu; Ademosun, Ayokunle O; Ademiluyi, Adedayo O; Omojokun, Olasunkanmi S; Nwanna, Esther E; Longe, Kuburat O

    2014-01-01

    Background. This study sought to investigate the antidiabetic and antihypertensive mechanisms of cocoa (Theobroma cacao) bean through inhibition of α-amylase, α-glucosidase, angiotensin-1 converting enzyme, and oxidative stress. Methodology. The total phenol and flavonoid contents of the water extractable phytochemicals from the powdered cocoa bean were determined and the effects of the extract on α-amylase, α-glucosidase, and angiotensin-1 converting enzyme activities were investigated in vitro. Furthermore, the radicals [1,1-diphenyl-2 picrylhydrazyl (DPPH), 2,2..-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), hydroxyl (OH), and nitric oxide (NO)] scavenging ability and ferric reducing antioxidant property of the extract were assessed. Results. The results revealed that the extract inhibited α-amylase (1.81 ± 0.22 mg/mL), α-glucosidase (1.84 ± 0.17 mg/mL), and angiotensin-1 converting enzyme (0.674 ± 0.06 mg/mL [lungs], 1.006 ± 0.08 mg/mL [heart]) activities in a dose-dependent manner and also showed dose-dependent radicals [DPPH (16.94 ± 1.34 mg/mL), NO (6.98 ± 0.886 mg/mL), OH (3.72 ± 0.26 mg/mL), and ABTS (15.7 ± 1.06 mmol/TEAC·g] scavenging ability. Conclusion. The inhibition of α-amylase, α-glucosidase, and angiotensin-1 converting enzyme activities by the cocoa bean extract could be part of the possible mechanism by which the extract could manage and/or prevent type-2 diabetes and hypertension.

  2. In Vitro Studies on the Antioxidant Property and Inhibition of α-Amylase, α-Glucosidase, and Angiotensin I-Converting Enzyme by Polyphenol-Rich Extracts from Cocoa (Theobroma cacao Bean

    Directory of Open Access Journals (Sweden)

    Ganiyu Oboh

    2014-01-01

    Full Text Available Background. This study sought to investigate the antidiabetic and antihypertensive mechanisms of cocoa (Theobroma cacao bean through inhibition of α-amylase, α-glucosidase, angiotensin-1 converting enzyme, and oxidative stress. Methodology. The total phenol and flavonoid contents of the water extractable phytochemicals from the powdered cocoa bean were determined and the effects of the extract on α-amylase, α-glucosidase, and angiotensin-1 converting enzyme activities were investigated in vitro. Furthermore, the radicals [1,1-diphenyl-2 picrylhydrazyl (DPPH, 2,2..-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid (ABTS, hydroxyl (OH, and nitric oxide (NO] scavenging ability and ferric reducing antioxidant property of the extract were assessed. Results. The results revealed that the extract inhibited α-amylase (1.81 ± 0.22 mg/mL, α-glucosidase (1.84 ± 0.17 mg/mL, and angiotensin-1 converting enzyme (0.674 ± 0.06 mg/mL [lungs], 1.006 ± 0.08 mg/mL [heart] activities in a dose-dependent manner and also showed dose-dependent radicals [DPPH (16.94 ± 1.34 mg/mL, NO (6.98 ± 0.886 mg/mL, OH (3.72 ± 0.26 mg/mL, and ABTS (15.7 ± 1.06 mmol/TEAC·g] scavenging ability. Conclusion. The inhibition of α-amylase, α-glucosidase, and angiotensin-1 converting enzyme activities by the cocoa bean extract could be part of the possible mechanism by which the extract could manage and/or prevent type-2 diabetes and hypertension.

  3. In Vitro Studies on the Antioxidant Property and Inhibition of α-Amylase, α-Glucosidase, and Angiotensin I-Converting Enzyme by Polyphenol-Rich Extracts from Cocoa (Theobroma cacao) Bean

    Science.gov (United States)

    Ademosun, Ayokunle O.; Ademiluyi, Adedayo O.; Omojokun, Olasunkanmi S.; Nwanna, Esther E.; Longe, Kuburat O.

    2014-01-01

    Background. This study sought to investigate the antidiabetic and antihypertensive mechanisms of cocoa (Theobroma cacao) bean through inhibition of α-amylase, α-glucosidase, angiotensin-1 converting enzyme, and oxidative stress. Methodology. The total phenol and flavonoid contents of the water extractable phytochemicals from the powdered cocoa bean were determined and the effects of the extract on α-amylase, α-glucosidase, and angiotensin-1 converting enzyme activities were investigated in vitro. Furthermore, the radicals [1,1-diphenyl-2 picrylhydrazyl (DPPH), 2,2..-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), hydroxyl (OH), and nitric oxide (NO)] scavenging ability and ferric reducing antioxidant property of the extract were assessed. Results. The results revealed that the extract inhibited α-amylase (1.81 ± 0.22 mg/mL), α-glucosidase (1.84 ± 0.17 mg/mL), and angiotensin-1 converting enzyme (0.674 ± 0.06 mg/mL [lungs], 1.006 ± 0.08 mg/mL [heart]) activities in a dose-dependent manner and also showed dose-dependent radicals [DPPH (16.94 ± 1.34 mg/mL), NO (6.98 ± 0.886 mg/mL), OH (3.72 ± 0.26 mg/mL), and ABTS (15.7 ± 1.06 mmol/TEAC·g] scavenging ability. Conclusion. The inhibition of α-amylase, α-glucosidase, and angiotensin-1 converting enzyme activities by the cocoa bean extract could be part of the possible mechanism by which the extract could manage and/or prevent type-2 diabetes and hypertension. PMID:25295218

  4. Soluble inhibitors/deactivators of cellulase enzymes from lignocellulosic biomass.

    Science.gov (United States)

    Kim, Youngmi; Ximenes, Eduardo; Mosier, Nathan S; Ladisch, Michael R

    2011-04-07

    Liquid hot water, steam explosion, and dilute acid pretreatments of lignocellulose generate soluble inhibitors which hamper enzymatic hydrolysis as well as fermentation of sugars to ethanol. Toxic and inhibitory compounds will vary with pretreatment and include soluble sugars, furan derivatives (hydroxymethyl fulfural, furfural), organic acids (acetic, formic and, levulinic acid), and phenolic compounds. Their effect is seen when an increase in the concentration of pretreated biomass in a hydrolysis slurry results in decreased cellulose conversion, even though the ratio of enzyme to cellulose is kept constant. We used lignin-free cellulose, Solka Floc, combined with mixtures of soluble components released during pretreatment of wood, to prove that the decrease in the rate and extent of cellulose hydrolysis is due to a combination of enzyme inhibition and deactivation. The causative agents were extracted from wood pretreatment liquid using PEG surfactant, activated charcoal or ethyl acetate and then desorbed, recovered, and added back to a mixture of enzyme and cellulose. At enzyme loadings of either 1 or 25mg protein/g glucan, the most inhibitory components, later identified as phenolics, decreased the rate and extent of cellulose hydrolysis by half due to both inhibition and precipitation of the enzymes. Full enzyme activity occurred when the phenols were removed. Hence detoxification of pretreated woods through phenol removal is expected to reduce enzyme loadings, and therefore reduce enzyme costs, for a given level of cellulose conversion. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Effect of cadmium on lung lysosomal enzymes in vitro

    International Nuclear Information System (INIS)

    Giri, S.N.; Hollinger, M.A.

    1995-01-01

    Labilization of lysosomal enzymes is often associated with the general process of inflammation. The present study investigated the effect of the pneumotoxin cadmium on the release and activity of two lung lysosomal enzymes. Incubation of rat lung lysosomes with cadmium resulted in the release of β-glucuronidase but not acid phosphatase. The failure to ''release'' acid phosphatase appears to be the result of a direct inhibitory effect of cadmium on this enzyme. The K I for cadmium was determined to be 26.3 μM. The differential effect of cadmium on these two lysosomal enzymes suggests that caution should be exercised in selecting the appropriate enzyme marker for assessing lysosomal fragility in the presence of this toxicant. Furthermore, the differential basal release rate of the two enzymes from lung lysosomes may reflect the cellular heterogeneity of the lung. (orig.)

  6. Antioxidative sulphated polygalactans from marine macroalgae as angiotensin-I converting enzyme inhibitors.

    Science.gov (United States)

    Makkar, Fasina; Chakraborty, Kajal

    2017-08-17

    Antioxidant and antihypertensive potential of the sulphated polygalactans isolated from the marine macroalgae Kappaphycus alvarezii and Gracilaria opuntia were assessed by utilising different in vitro systems. The galactans isolated from K. alvarezii possessed significantly greater antioxidative properties as determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH IC 90 0.97 mg/mL) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS .+ IC 90 0.72 mg/mL) scavenging activities than those isolated from G. opuntia (DPPH IC 90 1.2 mg/mL and ABTS 0.86 mg/mL). The sulphated polygalactan →4)-4-O-sulphonato-(2-O-methyl)-β-D-galactopyranosyl-(1→4)-3,6-anhydro-(2-O-methyl)-α-D-galactopyranan from K. alvarezii showed greater angiotensin-I-converting enzyme (ACE) inhibitory activity (IC 50 0.02 μg/mL) than →3)-4-O-sulphonato-(6-O-acetyl)-β-D-galactopyranosyl-(1→4)-3,6-anhydro-(2-O-sulphonato)-α-D-galactopyranosyl-(1→3)-4-O-sulphonato-(6-O-acetyl)-β-D-xylosyl-(1→3)-4-O-sulphonato-(6-O-acetyl)-β-D-galactopyranosyl-(1→4)-3,6-anhydro-(2-O-sulphonato)-α-D-galactopyranan motif extracted from G. opuntia (IC 50 0.70 μg/mL). Structure activity correlation studies displayed that the ACE inhibitory properties of titled polygalactans were directly proportional to their electronic properties and inversely with the steric and hydrophobic characteristics. Putative ACE inhibitory mechanism of action of sulphated galactans from marine macroalgae corroborated the structure bioactivity correlation analysis.

  7. Inhibitory Effects of 5,6,7-Trihydroxyflavones on Tyrosinase

    Directory of Open Access Journals (Sweden)

    Jun Kawabata

    2007-01-01

    Full Text Available Baicalein (1, 6-hydroxyapigenin (6, 6-hydroxygalangin (13 and 6-hydroxy-kaempferol (14, which are naturally occurring flavonoids from a set of 14 hydroxy-flavones tested, exhibited high inhibitory effects on tyrosinase with respect to L-DOPA,while each of the 5,6,7-trihydroxyflavones 1, 6, 13 or 14 acted as a cofactor tomonophenolase. Moreover, 6-hydroxykaempferol (14 showed the highest activity andwas a competitive inhibitor of tyrosinase compared to L-DOPA. 5,6,7-Trihydroxyflavones 1, 6, 13 or 14 showed also high antioxidant activities. Hence, weconclude that the 5,6,7-trihydroxy-flavones are useful as good depigmentation agentswith inhibitory effects in addition to their antioxidant properties.

  8. Antioxidant, Iron Chelating and Tyrosinase Inhibitory Activities of Extracts from Talinum triangulare Leach Stem

    Directory of Open Access Journals (Sweden)

    Ana Paula Oliveira Amorim

    2013-07-01

    Full Text Available The aim of this work is to evaluate the antioxidant activity against the radical species DPPH, the reducing capacity against Fe II ions, and the inhibitory activity on the tyrosinase enzyme of the T. triangulare. Hydromethanolic crude extract provided two fractions after the liquid/liquid partition with chloroform. The Folin-Ciocalteu method determined the total phenolic content of the crude extract (CE and the hydromethanolic fraction (Fraction 1, resulting in a concentration of 0.5853 g/100 g for Fraction 1, and 0.1400 g/100 g for the CE. Taking into account the results of the DPPH, the free radical scavenging capacity was confirmed. The formation of complexes with Fe II ions was evaluated by UV/visible spectrometry; results showed that CE has complexing power similar to the positive control (Gingko biloba extract.The inhibitory capacity of samples against the tyrosinase enzyme was determined by the oxidation of L-DOPA, providing IC50 values of 13.3 μg·mL−1 (CE and 6.6 μg·mL−1 (Fraction 1. The values indicate that Fraction 1 was more active and showed a higher inhibitory power on the tyrosinase enzyme than the ascorbic acid, used as positive control. The hydromethanolic extract of T. triangulare proved to have powerful antioxidant activity and to inhibit the tyrosinase enzyme; its potential is increased after the partition with chloroform.

  9. α-Glucosidase and tyrosinase inhibitory effects of an abietane type diterpenoid taxoquinone from Metasequoia glyptostroboides.

    Science.gov (United States)

    Bajpai, Vivek K; Park, Yong-Ha; Na, MinKyun; Kang, Sun Chul

    2015-03-26

    Nowadays plant derived natural compounds have gained huge amount of research attention especially in food and medicine industries due to their multitude of biological and therapeutic properties as alternative medicines. In this study, a diterpenoid compound taxoquinone, isolated from Metasequoia glyptostroboides was evaluated for its α-glucosidase and tyrosinase inhibitory efficacy in terms of its potent anti-diabetic and depigmentation potential, respectively. As a result, taxoquinone at the concentration range of 100-3,000 μg/mL and 200-1,000 μg/mL showed potent efficacy on inhibiting α-glucosidase and tyrosinase enzymes by 9.24-51.32% and 11.14-52.32%, respectively. The findings of this study clearly evident potent therapeutic efficacy of an abietane diterpenoid taxoquinone isolated from M. glyptostroboides with a possibility for using it as a novel candidate in food and medicine industry as a natural alternative medicine to prevent diabetes mellitus type-2 related disorders and as a depigmentation agent.

  10. Attenuation of Renovascular Damage in Zucker Diabetic Fatty Rat by NWT-03, an Egg Protein Hydrolysate with ACE- and DPP4-Inhibitory Activity

    NARCIS (Netherlands)

    Wang, Yumei; Landheer, S.; Gilst, van W.H.; Amerongen, van A.

    2012-01-01

    Background Dipeptidyl peptidase 4 (DPP4) and angiotensin-converting enzyme (ACE) are important target enzymes in glycemic control and renovascular protection. Here, we studied the effect of NWT-03, an egg protein hydrolysate with DPP4- and ACE-inhibitory activity, on renovascular damage in Zucker

  11. Attenuation of Renovascular Damage in Zucker Diabetic Fatty Rat by NWT-03, an Egg Protein Hydrolysate with ACE- and DPP4-Inhibitory Activity

    NARCIS (Netherlands)

    Wang, Yumei; Landheer, Sjoerd; van Gilst, Wiek H.; van Amerongen, Aart; Hammes, Hans-Peter; Henning, Robert H.; Deelman, Leo E.; Buikema, Hendrik

    2012-01-01

    Background: Dipeptidyl peptidase 4 (DPP4) and angiotensin-converting enzyme (ACE) are important target enzymes in glycemic control and renovascular protection. Here, we studied the effect of NWT-03, an egg protein hydrolysate with DPP4- and ACE-inhibitory activity, on renovascular damage in Zucker

  12. The Effects of Fungicide, Soil Fumigant, Bio-Organic Fertilizer and Their Combined Application on Chrysanthemum Fusarium Wilt Controlling, Soil Enzyme Activities and Microbial Properties

    Directory of Open Access Journals (Sweden)

    Shuang Zhao

    2016-04-01

    Full Text Available Sustained monoculture often leads to a decline in soil quality, in particular to the build-up of pathogen populations, a problem that is conventionally addressed by the use of either fungicide and/or soil fumigation. This practice is no longer considered to be either environmentally sustainable or safe. While the application of organic fertilizer is seen as a means of combating declining soil fertility, it has also been suggested as providing some control over certain soil-borne plant pathogens. Here, a greenhouse comparison was made of the Fusarium wilt control efficacy of various treatments given to a soil in which chrysanthemum had been produced continuously for many years. The treatments comprised the fungicide carbendazim (MBC, the soil fumigant dazomet (DAZ, the incorporation of a Paenibacillus polymyxa SQR21 (P. polymyxa SQR21, fungal antagonist enhanced bio-organic fertilizer (BOF, and applications of BOF combined with either MBC or DAZ. Data suggest that all the treatments evaluated show good control over Fusarium wilt. The MBC and DAZ treatments were effective in suppressing the disease, but led to significant decrease in urease activity and no enhancement of catalase activity in the rhizosphere soils. BOF including treatments showed significant enhancement in soil enzyme activities and microbial communities compared to the MBC and DAZ, evidenced by differences in bacterial/fungi (B/F ratios, Shannon–Wiener indexes and urease, catalase and sucrase activities in the rhizosphere soil of chrysanthemum. Of all the treatments evaluated, DAZ/BOF application not only greatly suppressed Fusarium wilt and enhanced soil enzyme activities and microbial communities but also promoted the quality of chrysanthemum obviously. Our findings suggest that combined BOF with DAZ could more effectively control Fusarium wilt disease of chrysanthemum.

  13. 2-Hexadecynoic acid inhibits plasmodial FAS-II enzymes and arrests erythrocytic and liver stage Plasmodium infections.

    Science.gov (United States)

    Tasdemir, Deniz; Sanabria, David; Lauinger, Ina L; Tarun, Alice; Herman, Rob; Perozzo, Remo; Zloh, Mire; Kappe, Stefan H; Brun, Reto; Carballeira, Néstor M

    2010-11-01

    Acetylenic fatty acids are known to display several biological activities, but their antimalarial activity has remained unexplored. In this study, we synthesized the 2-, 5-, 6-, and 9-hexadecynoic acids (HDAs) and evaluated their in vitro activity against erythrocytic (blood) stages of Plasmodium falciparum and liver stages of Plasmodium yoelii infections. Since the type II fatty acid biosynthesis pathway (PfFAS-II) has recently been shown to be indispensable for liver stage malaria parasites, the inhibitory potential of the HDAs against multiple P. falciparum FAS-II (PfFAS-II) elongation enzymes was also evaluated. The highest antiplasmodial activity against blood stages of P. falciparum was displayed by 5-HDA (IC(50) value 6.6 μg/ml), whereas the 2-HDA was the only acid arresting the growth of liver stage P. yoelii infection, in both flow cytometric assay (IC(50) value 2-HDA 15.3 μg/ml, control drug atovaquone 2.5 ng/ml) and immunofluorescence analysis (IC(50) 2-HDA 4.88 μg/ml, control drug atovaquone 0.37 ng/ml). 2-HDA showed the best inhibitory activity against the PfFAS-II enzymes PfFabI and PfFabZ with IC(50) values of 0.38 and 0.58 μg/ml (IC(50) control drugs 14 and 30 ng/ml), respectively. Enzyme kinetics and molecular modeling studies revealed valuable insights into the binding mechanism of 2-HDA on the target enzymes. All HDAs showed in vitro activity against Trypanosoma brucei rhodesiense (IC(50) values 3.7-31.7 μg/ml), Trypanosoma cruzi (only 2-HDA, IC(50) 20.2 μg/ml), and Leishmania donovani (IC(50) values 4.1-13.4 μg/ml) with generally low or no significant toxicity on mammalian cells. This is the first study to indicate therapeutic potential of HDAs against various parasitic protozoa. It also points out that the malarial liver stage growth inhibitory effect of the 2-HDA may be promoted via PfFAS-II enzymes. The lack of cytotoxicity, lipophilic nature, and calculated pharmacokinetic properties suggests that 2-HDA could be a useful compound to

  14. 2-Hexadecynoic Acid Inhibits Plasmodial FAS-II Enzymes and Arrest Erythrocytic and Liver Stage Plasmodium Infections

    Science.gov (United States)

    Tasdemir, Deniz; Sanabria, David; Lauinger, Ina L.; Tarun, Alice; Herman, Rob; Perozzo, Remo; Zloh, Mire; Kappe, Stefan H.; Brun, Reto; Carballeira, Néstor M.

    2010-01-01

    Acetylenic fatty acids are known to display several biological activities, but their antimalarial activity has remained unexplored. In this study, we synthesized the 2-, 5-, 6-, and 9-hexadecynoic acids (HDAs) and evaluated their in vitro activity against erythrocytic (blood) stages of Plasmodium falciparum and liver stages of P. yoelii infections. Since the type II fatty acid biosynthesis pathway (PfFAS-II) has recently been shown to be indispensable for liver stage malaria parasites, the inhibitory potential of the HDAs against multiple P. falciparum FAS-II (PfFAS-II) elongation enzymes was also evaluated. The highest antiplasmodial activity against blood stages of P. falciparum was displayed by 5-HDA (IC50 value 6.6. μg/ml), whereas the 2-HDA was the only acid arresting the growth of liver stage P. yoelii infection, in both flow cytometric assay (IC50 value 2-HDA 15.3 μg/ml, control drug atovaquone 2.5 ng/ml) and immunofluorescense analysis (IC50 2-HDA 4.88 μg/ml, control drug atovaquone 0.37 ng/ml). 2-HDA showed the best inhibitory against the PfFAS-II enzymes PfFabI and PfFabZ with IC50 values of 0.38 and 0.58 μg/ml (IC50 control drugs 14 and 30 ng/ml) respectively. Enzyme kinetics and molecular modeling studies revealed valuable insights into the binding mechanism of 2-HDA on the target enzymes. All HDAs showed in vitro activity against Trypanosoma brucei rhodesiense (IC50 values 3.7–31.7 μg/ml), Trypanosoma cruzi (only 2-HDA, IC50 20.2 μg/ml), and Leishmania donovani (IC50 values 4.1–13.4 μg/ml) with generally low or no significant toxicity on mammalian cells. This is the first study to indicate therapeutic potential of HDAs against various parasitic protozoa. It also points out that the malarial liver stage growth inhibitory effect of the 2-HDA may be promoted via PfFAS-II enzymes. The lack of cytotoxicity, lipophilic nature and calculated pharmacokinetic properties suggest that 2-HDA could be a useful compound to study the interaction of fatty

  15. Enzymes in CO2 Capture

    DEFF Research Database (Denmark)

    Fosbøl, Philip Loldrup; Gladis, Arne; Thomsen, Kaj

    The enzyme Carbonic Anhydrase (CA) can accelerate the absorption rate of CO2 into aqueous solutions by several-fold. It exist in almost all living organisms and catalyses different important processes like CO2 transport, respiration and the acid-base balances. A new technology in the field...... of carbon capture is the application of enzymes for acceleration of typically slow ternary amines or inorganic carbonates. There is a hidden potential to revive currently infeasible amines which have an interesting low energy consumption for regeneration but too slow kinetics for viable CO2 capture. The aim...... of this work is to discuss the measurements of kinetic properties for CA promoted CO2 capture solvent systems. The development of a rate-based model for enzymes will be discussed showing the principles of implementation and the results on using a well-known ternary amine for CO2 capture. Conclusions...

  16. Identification of the C-Terminal GH5 Domain from CbCel9B/Man5A as the First Glycoside Hydrolase with Thermal Activation Property from a Multimodular Bifunctional Enzyme.

    Directory of Open Access Journals (Sweden)

    Rong Wang

    Full Text Available Caldicellulosiruptor bescii encodes at least six unique multimodular glycoside hydrolases crucial for plant cell wall polysaccharides degradation, with each having two catalytic domains separated by two to three carbohydrate binding modules. Among the six enzymes, three have one N- or C-terminal GH5 domain with identical amino acid sequences. Despite a few reports on some of these multimodular enzymes, little is known about how the conserved GH5 domains behave, which are believed to be important due to the gene duplication. We thus cloned a representative GH5 domain from the C-terminus of a multimodular protein, i.e. the bifunctional cellulase/mannanase CbCel9B/Man5A which has been reported, and expressed it in Escherichia coli. Without any appending CBMs, the recombinant CbMan5A was still able to hydrolyze a variety of mannan substrates with different backbone linkages or side-chain decorations. While CbMan5A displayed the same pH optimum as CbCel9B/Man5A, it had an increased optimal temperature (90°C and moreover, was activated by heating at 70°C and 80°C, a property not ever reported for the full-length protein. The turnover numbers of CbMan5A on mannan substrates were, however, lower than those of CbCel9B/Man5A. These data suggested that evolution of CbMan5A and the other domains into a single polypeptide is not a simple assembly; rather, the behavior of one module may be affected by the other ones in the full-length enzyme. The differential scanning calorimetry analysis further indicated that heating CbMan5A was not a simple transition state process. To the best knowledge of the authors, CbMan5A is the first glycoside hydrolase with thermal activation property identified from a multimodular bifunctional enzyme.

  17. New Biflavonoids with α-Glucosidase and Pancreatic Lipase Inhibitory Activities from Boesenbergia rotunda

    Directory of Open Access Journals (Sweden)

    Nutputsorn Chatsumpun

    2017-10-01

    Full Text Available Roots of Boesenbergia rotunda (L. Mansf. are prominent ingredients in the cuisine of several Asian countries, including Thailand, Malaysia, Indonesia, India, and China. An extract prepared from the roots of this plant showed strong inhibitory activity against enzymes α-glucosidase and pancreatic lipase and was subjected to chromatographic separation to identify the active components. Three new biflavonoids of the flavanone-chalcone type (9, 12, and 13 were isolated, along with 12 known compounds. Among the 15 isolates, the three new compounds showed stronger inhibitory activity against α-glucosidase than the drug acarbose but displayed lower pancreatic lipase inhibitory effect than the drug orlistat. The results indicated the potential of B. rotunda roots as a functional food for controlling after-meal blood glucose levels.

  18. Phenolic compounds and related enzymes as determinants of sorghum for food use

    NARCIS (Netherlands)

    Dicko, M.H.; Gruppen, H.; Traore, A.S.; Voragen, A.G.J.; Berkel, van W.J.H.

    2006-01-01

    Phenolic compounds and related enzymes such as phenol biosynthesizing enzymes (phenylalanine ammonia lyase) and phenol catabolizing enzymes (polyphenol oxidase and peroxidase) are determinants for sorghum utilization as human food because they influence product properties during and after sorghum

  19. [Interaction between CYP450 enzymes and metabolism of traditional Chinese medicine as well as enzyme activity assay].

    Science.gov (United States)

    Lu, Tu-lin; Su, Lian-lin; Ji, De; Gu, Wei; Mao, Chun-qin

    2015-09-01

    Drugs are exogenous compounds for human bodies, and will be metabolized by many enzymes after administration. CYP450 enzyme, as a major metabolic enzyme, is an important phase I drug metabolizing enzyme. In human bodies, about 75% of drug metabolism is conducted by CYP450 enzymes, and CYP450 enzymes is the key factor for drug interactions between traditional Chinese medicine( TCM) -TCM, TCM-medicine and other drug combination. In order to make clear the interaction between metabolic enzymes and TCM metabolism, we generally chose the enzymatic activity as an evaluation index. That is to say, the enhancement or reduction of CYP450 enzyme activity was used to infer the inducing or inhibitory effect of active ingredients and extracts of traditional Chinese medicine on enzymes. At present, the common method for measuring metabolic enzyme activity is Cocktail probe drugs, and it is the key to select the suitable probe substrates. This is of great significance for study drug's absorption, distribution, metabolism and excretion (ADME) process in organisms. The study focuses on the interaction between TCMs, active ingredients, herbal extracts, cocktail probe substrates as well as CYP450 enzymes, in order to guide future studies.

  20. Phytochemical screening and in vitro acetylcholinesterase inhibitory ...

    African Journals Online (AJOL)

    Phytochemical screening and in vitro acetylcholinesterase inhibitory activity of seven plant extracts. Titilayo Johnson, Oduje A. Akinsanmi, Enoch J. Banbilbwa, Tijani A. Yahaya, Karima Abdulaziz, Kolade Omole ...

  1. COMPARATIVE EVALUATION OF INHIBITORY ACTIVITY OF ...

    African Journals Online (AJOL)

    Osondu

    2013-02-26

    Feb 26, 2013 ... especially the four bacteria isolates used in this study are present in the epiphgram of both normal and ... Keyword: Albino snail, Archachatina marginata, Inhibitory activity, Epiphgram, Bacteria isolate. Introduction .... evolution.

  2. How Do Enzymes 'Meet' Nanoparticles and Nanomaterials?

    Science.gov (United States)

    Chen, Ming; Zeng, Guangming; Xu, Piao; Lai, Cui; Tang, Lin

    2017-11-01

    Enzymes are fundamental biological catalysts responsible for biological regulation and metabolism. The opportunity for enzymes to 'meet' nanoparticles and nanomaterials is rapidly increasing due to growing demands for applications in nanomaterial design, environmental monitoring, biochemical engineering, and biomedicine. Therefore, understanding the nature of nanomaterial-enzyme interactions is becoming important. Since 2014, enzymes have been used to modify, degrade, or make nanoparticles/nanomaterials, while numerous nanoparticles/nanomaterials have been used as materials for enzymatic immobilization and biosensors and as enzyme mimicry. Among the various nanoparticles and nanomaterials, metal nanoparticles and carbon nanomaterials have received extensive attention due to their fascinating properties. This review provides an overview about how enzymes meet nanoparticles and nanomaterials. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Inhibitory Effects of Resveratrol Analogs on Mushroom Tyrosinase Activity

    Directory of Open Access Journals (Sweden)

    Nádia Rezende Barbosa Raposo

    2012-10-01

    Full Text Available Skin pigmentation disorders typically involve an overproduction or uneven distribution of melanin, which results in skin spots. Resveratrol can inhibit tyrosinase, the active enzyme in the synthesis of melanin, but it does not inhibit the synthesis of melanin to an extent that enables its use alone as a skin whitening agent in pharmaceutical formulations, so its use as a coadjuvant in treatment of hyperpigmentation is suggested. Six resveratrol analogs were tested for tyrosinase inhibitory activity in vitro. Among the analogs tested, compound D was the most powerful tyrosinase inhibitor (IC50 = 28.66 µg/mL, two times more active than resveratrol (IC50 = 57.05 µg/mL, followed by the analogs A, E, B, F and C, respectively. This demonstrated that the hydroxylation at C4' on the phenolic ring was the molecular modification with most importance for the observed activity.

  4. Role of inhibitory feedback for information processing in thalamocortical circuits

    International Nuclear Information System (INIS)

    Mayer, Joerg; Schuster, Heinz Georg; Claussen, Jens Christian

    2006-01-01

    The information transfer in the thalamus is blocked dynamically during sleep, in conjunction with the occurrence of spindle waves. In order to describe the dynamic mechanisms which control the sensory transfer of information, it is necessary to have a qualitative model for the response properties of thalamic neurons. As the theoretical understanding of the mechanism remains incomplete, we analyze two modeling approaches for a recent experiment by Le Masson et al. [Nature (London) 417, 854 (2002)] on the thalamocortical loop. We use a conductance based model in order to motivate an extension of the Hindmarsh-Rose model, which mimics experimental observations of Le Masson et al. Typically, thalamic neurons posses two different firing modes, depending on their membrane potential. At depolarized potentials, the cells fire in a single spike mode and relay synaptic inputs in a one-to-one manner to the cortex. If the cell gets hyperpolarized, T-type calcium currents generate burst-mode firing which leads to a decrease in the spike transfer. In thalamocortical circuits, the cell membrane gets hyperpolarized by recurrent inhibitory feedback loops. In the case of reciprocally coupled excitatory and inhibitory neurons, inhibitory feedback leads to metastable self-sustained oscillations, which mask the incoming input, and thereby reduce the information transfer significantly

  5. [State of Fungal Lipases of Rhizopus microsporus, Penicillium sp. and Oospora lactis in Border Layers Water-Solid Phase and Factors Affecting Catalytic Properties of Enzymes].

    Science.gov (United States)

    Khasanov, Kh T; Davranov, K; Rakhimov, M M

    2015-01-01

    We demonstrated that a change in the catalytic activity of fungal lipases synthesized by Rhizopus microsporus, Penicillium sp. and Oospora lactis and their ability to absorb on different sorbents depended on the nature of groups on the solid phase surface in the model systems water: lipid and water: solid phase. Thus, the stability of Penicillium sp. lipases increased 85% in the presence ofsorsilen or DEAE-cellulose, and 55% of their initial activity respectively was preserved. In the presence of silica gel and CM-cellulose, a decreased rate of lipid hydrolysis by Pseudomonas sp. enzymes was observed in water medium, and the hydrolysis rate increased by 2.4 and 1.5 times respectively in the presence of aminoaerosil and polykefamid. In an aqueous-alcohol medium, aminoaerosil and polykefamid decreased the rate of substrate hydrolysis by more than 30 times. The addition of aerosil to aqueous and aqueous-alcohol media resulted in an increase in the hydrolysis rate by 1.2-1.3 times. Sorsilen stabilized Penicillium sp. lipase activity at 40, 45, 50 and 55 degrees C. Either stabilization or inactivation of lipases was observed depending on the pH of the medium and the nature of chemical groups localized on the surface of solid phase. The synthetizing activity of lipases also changed depending on the conditions.

  6. Impact of ultraviolet radiation treatments on the physicochemical properties, antioxidants, enzyme activity and microbial load in freshly prepared hand pressed strawberry juice.

    Science.gov (United States)

    Bhat, Rajeev; Stamminger, Rainer

    2015-07-01

    Freshly prepared, hand-pressed strawberry fruit juice was exposed to ultraviolet radiation (254 nm) at room temperature (25 ℃ ± 1 ℃) for 15, 30 and 60 min with 0 min serving as control. Results revealed decrease in pH, total soluble solids and titratable acidity, while colour parameters (L*, a* and b* values) and clarity of juice (% transmittance) increased significantly. All the results corresponded to exposure time to ultraviolet radiation. Bioactive compounds (total phenolics, ascorbic acid and anthocyanins) decreased along with a recorded reduction in polyphenol oxidase enzyme and 1,1-diphenyl-2-picryl hydrazyl radical scavenging activities, which were again dependent on exposure time. Results on the microbial studies showed significant reduction by 2-log cycles in aerobic plate count as well as in total yeast and mould counts. Though negative results were observed for certain parameters, this is the first time it was endeavoured to demonstrate the impact of ultraviolet radiation radiation on freshly prepared, hand-pressed strawberries juice. © The Author(s) 2014.

  7. Generation of functional inhibitory synapses incorporating defined combinations of GABA(A or glycine receptor subunits

    Directory of Open Access Journals (Sweden)

    Christine Laura Dixon

    2015-12-01

    Full Text Available Fast inhibitory neurotransmission in the brain is mediated by wide range of GABAA receptor (GABAAR and glycine receptor (GlyR isoforms, each with different physiological and pharmacological properties. Because multiple isoforms are expressed simultaneously in most neurons, it is difficult to define the properties of inhibitory postsynaptic currents mediated by individual isoforms in vivo. Although recombinant expression systems permit the expression of individual isoforms in isolation, they require exogenous agonist application which cannot mimic the dynamic neurotransmitter profile characteristic of native synapses. We describe a neuron-HEK293 cell co-culture technique for generating inhibitory synapses incorporating defined combinations of GABAAR or GlyR subunits. Primary neuronal cultures, prepared from embryonic rat cerebral cortex or spinal cord, are used to provide presynaptic GABAergic and glycinergic terminals, respectively. When the cultures are mature, HEK293 cells expressing the subunits of interest plus neuroligin 2A are plated onto the neurons, which rapidly form synapses onto HEK293 cells. Patch clamp electrophysiology is then used to analyze the physiological and pharmacological properties of the inhibitory postsynaptic currents mediated by the recombinant receptors. The method is suitable for investigating the kinetic properties or the effects of drugs on inhibitory postsynaptic currents mediated by defined GABAAR or GlyR isoforms of interest, the effects of hereditary disease mutations on the formation and function of both types of synapses, and synaptogenesis and synaptic clustering mechanisms. The entire cell preparation procedure takes 2 – 5 weeks.

  8. Rapid Identification of Aldose Reductase Inhibitory Compounds from Perilla frutescens

    Directory of Open Access Journals (Sweden)

    Ji Hun Paek

    2013-01-01

    Full Text Available The ethyl acetate (EtOAc soluble fraction of methanol extracts of Perilla frutescens (P. frutescens inhibits aldose reductase (AR, the key enzyme in the polyol pathway. Our investigation of inhibitory compounds from the EtOAc soluble fraction of P. frutescens was followed by identification of the inhibitory compounds by a combination of HPLC microfractionation and a 96-well enzyme assay. This allowed the biological activities to be efficiently matched with selected HPLC peaks. Structural analyses of the active compounds were performed by LC-MSn. The main AR inhibiting compounds were tentatively identified as chlorogenic acid and rosmarinic acid by LC-MSn. A two-step high speed counter current chromatography (HSCCC isolation method was developed with a solvent system of n-hexane-ethyl acetate-methanol-water at 1.5 : 5 : 1 : 5, v/v and 3 : 7 : 5 : 5, v/v. The chemical structures of the isolated compounds were determined by 1H- and 13C-nuclear magnetic resonance spectrometry (NMR. The main compounds inhibiting AR in the EtOAc fraction of methanol extracts of P. frutescens were identified as chlorogenic acid (2 (IC50 = 3.16 μM, rosmarinic acid (4 (IC50 = 2.77 μM, luteolin (5 (IC50 = 6.34 μM, and methyl rosmarinic acid (6 (IC50 = 4.03 μM.

  9. ENZYME RESISTANCE OF GENETICALLY MODIFIED STARCH POTATOES

    Directory of Open Access Journals (Sweden)

    A. Sh. Mannapova

    2015-01-01

    Full Text Available Here in this article the justification of expediency of enzyme resistant starch use in therapeutic food products is presented . Enzyme resistant starch is capable to resist to enzymatic hydrolysis in a small intestine of a person, has a low glycemic index, leads to decrease of postprandial concentration of glucose, cholesterol, triglycerides in blood and insulin reaction, to improvement of sensitivity of all organism to insulin, to increase in sense of fulness and to reduction of adjournment of fats. Resistant starch makes bifidogenшс impact on microflora of a intestine of the person, leads to increase of a quantity of lactobacillus and bifidobacterium and to increased production of butyric acid in a large intestine. In this regard the enzyme resistant starch is an important component in food for prevention and curing of human diseases such as diabetes, obesity, colitis, a cancer of large and direct intestine. One method is specified by authors for imitation of starch digestion in a human body. This method is based on the definition of an enzyme resistance of starch in vitro by its hydrolysis to glucose with application of a glucoamylase and digestive enzyme preparation Pancreatin. This method is used in researches of an enzyme resistance of starch, of genetically modified potato, high amylose corn starch Hi-Maize 1043 and HYLON VII (National Starch Food Innovation, USA, amylopectin and amylose. It is shown that the enzyme resistance of the starch emitted from genetically modified potatoes conforms to the enzyme resistance of the high amylose corn starch “Hi-Maize 1043 and HYLON VII starch”, (National Starch Food Innovation, the USA relating to the II type of enzyme resistant starch. It is established that amylopectin doesn't have the enzyme resistant properties. The results of researches are presented. They allow us to make the following conclusion: amylose in comparison with amylopectin possesses higher enzyme resistance and gives to

  10. Some characteristics of a raw starch digestion inhibitory factor from Aspergillus niger

    Energy Technology Data Exchange (ETDEWEB)

    Towprayoon, S.; Saha, B.C.; Fujio, Yusaku; Ueda, Seinosuke

    1988-09-01

    The effect of an inhibitory factor (IF) from Aspergillus niger 19 on raw starch digestion by pure glucoamylase I of black Aspergillus, pure glucoamylase of Rhizopus niveus, bacterial ..cap alpha..-amylase, fungal ..cap alpha..-amylase and various combination was investigated. The IF caused higher inhibition of raw starch hydrolysis by the combined action of glucoamylase and fungal ..cap alpha..-amylase than of hydrolysis by the individual enzymes. A protein moiety of IF might play an active part in this inhibition phenomenon. The IF was found to starch granules, preventing hydrolysis by the enzymes, and caused decreased raw starch hydrolysis yields.

  11. Purification, properties, and N-terminal amino acid sequence of homogeneous Escherichia coli 2-amino-3-ketobutyrate CoA ligase, a pyridoxal phosphate-dependent enzyme.

    Science.gov (United States)

    Mukherjee, J J; Dekker, E E

    1987-10-25

    Starting with 100 g (wet weight) of a mutant of Escherichia coli K-12 forced to grow on L-threonine as sole carbon source, we developed a 6-step procedure that provides 30-40 mg of homogeneous 2-amino-3-ketobutyrate CoA ligase (also called aminoacetone synthetase or synthase). This ligase, which catalyzes the cleavage/condensation reaction between 2-amino-3-ketobutyrate (the presumed product of the L-threonine dehydrogenase-catalyzed reaction) and glycine + acetyl-CoA, has an apparent molecular weight approximately equal to 85,000 and consists of two identical (or nearly identical) subunits with Mr = 42,000. Computer analysis of amino acid composition data, which gives the best fit nearest integer ratio for each residue, indicates a total of 387 amino acids/subunit with a calculated Mr = 42,093. Stepwise Edman degradation provided the N-terminal sequence of the first 21 amino acids. It is a pyridoxal phosphate-dependent enzyme since (a) several carbonyl reagents caused greater than 90% loss of activity, (b) dialysis against buffer containing hydroxylamine resulted in 89% loss of activity coincident with an 86% decrease in absorptivity at 428 nm, (c) incubation of the apoenzyme with 20 microM pyridoxal phosphate showed a parallel recovery (greater than 90%) of activity and 428-nm absorptivity, and (d) reduction of the holoenzyme with NaBH4 resulted in complete inactivation, disappearance of a new absorption maximum at 333 nm. Strict specificity for glycine is shown but acetyl-CoA (100%), n-propionyl-CoA (127%), or n-butyryl-CoA (16%) is utilized in the condensation reaction. Apparent Km values for acetyl-CoA, n-propionyl-CoA, and glycine are 59 microM, 80 microM, and 12 mM, respectively; the pH optimum = 7.5. Added divalent metal ions or sulfhydryl compounds inhibited catalysis of the condensation reaction.

  12. Cloning and Expression of Phytase appA Gene from Shigella sp. CD2 in Pichia pastoris and Comparison of Properties with Recombinant Enzyme Expressed in E. coli.

    Directory of Open Access Journals (Sweden)

    Moushree Pal Roy

    Full Text Available The phytase gene appAS was isolated from Shigella sp. CD2 genomic library. The 3.8 kb DNA fragment contained 1299 bp open reading frame encoding 432 amino acid protein (AppAS with 22 amino acid signal peptide at N-terminal and three sites of N-glycosylation. AppAS contained the active site RHGXRXP and HDTN sequence motifs, which are conserved among histidine acid phosphatases. It showed maximum identity with phytase AppA of Escherichia coli and Citrobacter braakii. The appAS was expressed in Pichia pastoris and E. coli to produce recombinant phytase rAppAP and rAppAE, respectively. Purified glycosylated rAppAP and nonglycosylated rAppAE had specific activity of 967 and 2982 U mg(-1, respectively. Both had pH optima of 5.5 and temperature optima of 60°C. Compared with rAppAE, rAppAP was 13 and 17% less active at pH 3.5 and 7.5 and 11 and 18% less active at temperature 37 and 50°C, respectively; however, it was more active at higher incubation temperatures. Thermotolerance of rAppAP was 33% greater at 60°C and 24% greater at 70°C, when compared with rAppAE. Both the recombinant enzymes showed high specificity to phytate and resistance to trypsin. To our knowledge, this is the first report on cloning and expression of phytase from Shigella sp.

  13. Cloning and Expression of Phytase appA Gene from Shigella sp. CD2 in Pichia pastoris and Comparison of Properties with Recombinant Enzyme Expressed in E. coli.

    Science.gov (United States)

    Pal Roy, Moushree; Mazumdar, Deepika; Dutta, Subhabrata; Saha, Shyama Prasad; Ghosh, Shilpi

    2016-01-01

    The phytase gene appAS was isolated from Shigella sp. CD2 genomic library. The 3.8 kb DNA fragment contained 1299 bp open reading frame encoding 432 amino acid protein (AppAS) with 22 amino acid signal peptide at N-terminal and three sites of N-glycosylation. AppAS contained the active site RHGXRXP and HDTN sequence motifs, which are conserved among histidine acid phosphatases. It showed maximum identity with phytase AppA of Escherichia coli and Citrobacter braakii. The appAS was expressed in Pichia pastoris and E. coli to produce recombinant phytase rAppAP and rAppAE, respectively. Purified glycosylated rAppAP and nonglycosylated rAppAE had specific activity of 967 and 2982 U mg(-1), respectively. Both had pH optima of 5.5 and temperature optima of 60°C. Compared with rAppAE, rAppAP was 13 and 17% less active at pH 3.5 and 7.5 and 11 and 18% less active at temperature 37 and 50°C, respectively; however, it was more active at higher incubation temperatures. Thermotolerance of rAppAP was 33% greater at 60°C and 24% greater at 70°C, when compared with rAppAE. Both the recombinant enzymes showed high specificity to phytate and resistance to trypsin. To our knowledge, this is the first report on cloning and expression of phytase from Shigella sp.

  14. Enzyme inhibition by iminosugars

    DEFF Research Database (Denmark)

    López, Óscar; Qing, Feng-Ling; Pedersen, Christian Marcus

    2013-01-01

    Imino- and azasugar glycosidase inhibitors display pH dependant inhibition reflecting that both the inhibitor and the enzyme active site have groups that change protonation state with pH. With the enzyme having two acidic groups and the inhibitor one basic group, enzyme-inhibitor complexes...

  15. Identification of novel dipeptidyl peptidase IV (DPP-IV) inhibitory peptides in camel milk protein hydrolysates.

    Science.gov (United States)

    Nongonierma, Alice B; Paolella, Sara; Mudgil, Priti; Maqsood, Sajid; FitzGerald, Richard J

    2018-04-01

    Nine novel dipeptidyl peptidase IV (DPP-IV) inhibitory peptides (FLQY, FQLGASPY, ILDKEGIDY, ILELA, LLQLEAIR, LPVP, LQALHQGQIV, MPVQA and SPVVPF) were identified in camel milk proteins hydrolysed with trypsin. This was achieved using a sequential approach combining liquid chromatography tandem mass spectrometry (LC-MS/MS), qualitative/quantitative structure activity relationship (QSAR) and confirmatory studies with synthetic peptides. The most potent camel milk protein-derived DPP-IV inhibitory peptides, LPVP and MPVQA, had DPP-IV half maximal inhibitory concentrations (IC 50 ) of 87.0 ± 3.2 and 93.3 ± 8.0 µM, respectively. DPP-IV inhibitory peptide sequences identified within camel and bovine milk protein hydrolysates generated under the same hydrolysis conditions differ. This was linked to differences in enzyme selectivity for peptide bond cleavage of camel and bovine milk proteins as well as dissimilarities in their amino acid sequences. Camel milk proteins contain novel DPP-IV inhibitory peptides which may play a role in the regulation of glycaemia in humans. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Preparation of ACE Inhibitory Peptides from Mytilus coruscus Hydrolysate Using Uniform Design

    Directory of Open Access Journals (Sweden)

    Jin-Chao Wu

    2013-01-01

    Full Text Available The angiotensin-I-converting enzyme (ACE inhibitory peptides from mussel, Mytilus coruscus, were investigated and the variable factors, protease concentration, hydrolysis time, pH, and temperature, were optimized using Uniform Design, a new statistical experimental method. The results proved that the hydrolysate of alkali proteases had high ACE-inhibitory activity, especially the alkali protease E1. Optimization by Uniform Design showed that the best hydrolysis conditions for preparation of ACE-inhibitory peptides from Mytilus coruscus were protease concentration of 36.0 U/mL, hydrolysis time of 2.7 hours, pH 8.2, and Temperature at 59.5°C, respectively. The verification experiments under optimum conditions showed that the ACE-inhibitory activity (91.3% were agreed closely with the predicted activity of 90.7%. The amino acid composition analysis of Mytilus coruscus ACE-inhibitory peptides proved that it had high percent of lysine, leucine, glycine, aspartic acid, and glutamic acid.

  17. Engineering Cellulase Enzymes for Bioenergy

    Science.gov (United States)

    Atreya, Meera Elizabeth

    Sustainable energy sources, such as biofuels, offer increasingly important alternatives to fossil fuels that contribute less to global climate change. The energy contained within cellulosic biofuels derives from sunlight energy stored in the form of carbon-carbon bonds comprising sugars such as glucose. Second-generation biofuels are produced from lignocellulosic biomass feedstocks, including agricultural waste products and non-food crops like Miscanthus, that contain lignin and the polysaccharides hemicellulose and cellulose. Cellulose is the most abundant biological material on Earth; it is a polymer of glucose and a structural component of plant cell walls. Accessing the sugar is challenging, as the crystalline structure of cellulose resists degradation; biochemical and thermochemical means can be used to depolymerize cellulose. Cellulase enzymes catalyze the biochemical depolymerization of cellulose into glucose. Glucose can be used as a carbon source for growth of a biofuel-producing microorganism. When it converts glucose to a hydrocarbon fuel, this microbe completes the biofuels process of transforming sunlight energy into accessible, chemical energy capable of replacing non-renewable transportation fuels. Due to strong intermolecular interactions between polymer chains, cellulose is significantly more challenging to depolymerize than starch, a more accessible polymer of glucose utilized in first-generation biofuels processes (often derived from corn). While most mammals cannot digest cellulose (dietary fiber), certain fungi and bacteria produce cellulase enzymes capable of hydrolyzing it. These organisms secrete a wide variety of glycoside hydrolase and other classes of enzymes that work in concert. Because cellulase enzymes are slow-acting and expensive to produce, my aim has been to improve the properties of these enzymes as a means to make a cellulosic biofuels process possible that is more efficient and, consequently, more economical than current

  18. Activity modulation of microbial enzymes by llama (Lama glama) heavy-chain polyclonal antibodies during in vivo immune responses.

    Science.gov (United States)

    Ferrari, A; Weill, F S; Paz, M L; Cela, E M; González Maglio, D H; Leoni, J

    2012-03-01

    Since they were first described in 1993, it was found that recombinant variable fragments (rVHHs) of heavy-chain antibodies (HCAbs) from Camelidae have unusual biophysical properties, as well as a special ability to interact with epitopes that are cryptic for conventional Abs. It has been assumed that in vivo raised polyclonal HCAbs (pHCAbs) should behave in a similar manner than rVHHs; however, this assumption has not been tested sufficiently. Furthermore, our own preliminary work on a single serum sample from a llama immunized with a β-lactamase, has suggested that pHCAbs have no special ability to down-modulate catalytic activity. In this work, we further explored the interaction of pHCAbs from four llamas raised against two microbial enzymes and analyzed it within a short and a long immunization plan. The relative contribution of pHCAbs to serum titer was found to be low compared with that of the most abundant conventional subisotype (IgG(1)), during the whole immunization schedule. Furthermore, pHCAbs not only failed to inhibit the enzymes, but also activated one of them. Altogether, these results suggest that raising high titer inhibitory HCAbs is not a straightforward strategy - neither as a biotechnological strategy nor in the biological context of an immune response against infection - as raising inhibitory rVHHs.

  19. Phenolic-rich extracts of Eurycoma longifolia and Cylicodiscus gabunensis inhibit enzymes responsible for the development of erectile dysfunction and are antioxidants.

    Science.gov (United States)

    Oboh, Ganiyu; Adebayo, Adeniyi A; Ademosun, Ayokunle O

    2018-05-19

    Herbs have been used from ages to manage male sexual dysfunction. Hence, this study sought to investigate the effects of Eurycoma longifolia (EL) and Cylicodiscus gabunensis (CG) stem bark extracts on some enzymes implicated in erectile dysfunction in vitro. The extracts were prepared, and their effects on phosphodiesterase-5 (PDE-5), arginase, and angiotensin-1-converting enzyme (ACE) as well as pro-oxidant-induced lipid peroxidation were assessed. Furthermore, phenolic contents were determined, and their components were characterized and quantified using high-performance liquid chromatography with diode array detector (HPLC-DAD). The results revealed that the extracts inhibited PDE-5, arginase, and ACE in a concentration-dependent manner. However, IC50 values revealed that CG had higher inhibitory potential on PDE-5 (IC50=204.4 μg/mL), arginase (IC50=39.01 μg/mL), and ACE (IC50=48.81 μg/mL) than EL. In addition, the extracts inhibited pro-oxidant-induced lipid peroxidation in penile tissue homogenate. HPLC-DAD analysis showed that CG is richer in phenolic compounds than EL, and this could be responsible for higher biological activities observed in CG than EL. Hence, the observed antioxidant property and inhibitory action of CG and EL on enzymes relevant to erectile dysfunction in vitro could be part of possible mechanisms underlying their involvement in traditional medicine for the management of male sexual dysfunction.

  20. Endogenous proteolytic enzymes--a study of their impact on cod (Gadus morhua) muscle proteins and textural properties in a fermented product.

    Science.gov (United States)

    Yang, Fang; Rustad, Turid; Xu, Yanshun; Jiang, Qixing; Xia, Wenshui

    2015-04-01

    The aim of this study was to investigate endogenous proteolytic activities in a cod product and their impact on muscle proteins and textural properties during fermentation and storage. The result of specific proteolytic activities showed that cathepsins, especially cathepsin B, had the highest activities during fermentation and storage. SDS-PAGE indicated more degradation of myofibrillar proteins by cathepsin L than other proteases and that the hydrolysis by cathepsins was pronounced in the last stage of fermentation. Texture analysis showed that cathepsins had a negative impact on gel strength and this impact increased in the last stage of fermentation. However the product still had a firm texture. During storage (4 °C) for one week, no significant changes were seen in the gel strength. In conclusion, cathepsins had more impact on muscle proteins and textural properties than other proteases during fermentation but had little impact on gel strength during storage at 4 °C. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. A virus-based single-enzyme nanoreactor

    NARCIS (Netherlands)

    Comellas Aragones, M.; Engelkamp, H.; Claessen, V.I.; Sommerdijk, N.A.J.M.; Rowan, A.E.; Christianen, P.C.M.; Maan, J.C.; Verduin, B.J.M.; Cornelissen, J.J.L.M.; Nolte, R.J.M.

    2007-01-01

    Most enzyme studies are carried out in bulk aqueous solution, at the so-called ensemble level, but more recently studies have appeared in which enzyme activity is measured at the level of a single molecule, revealing previously unseen properties. To this end, enzymes have been chemically or

  2. Antitumor activity and inhibitory effects on cancer stem cell-like properties of Adeno-associated virus (AAV) -mediated Bmi-1 interference driven by Bmi-1 promoter for gastric cancer

    Science.gov (United States)

    Wang, Xiaofeng; Liu, Xinyang; Huang, Mingzhu; Gan, Lu; Cheng, Yufan; Li, Jin

    2016-01-01

    Bmi-1 is aberrantly activated in various cancers and plays a vital role in maintaining the self-renewal of stem cells. Our previous research revealed that Bmi-1 was overexpressed in gastric cancer (GC) and it's overexpression was an independent negative prognostic factor, suggesting it can be a therapeutic target. The main purpose of this investigation was to explore the antitumor activity of Bmi-1 interference driven by its own promoter (Ad-Bmi-1i) for GC. In this study, we used adenoviral vector to deliver Bmi-1 shRNA driven by its own promoter to treat GC. Our results revealed that Ad-Bmi-1i could selectively silence Bmi-1 in GC cells which overexpress Bmi-1 and suppress the malignant phenotypes and stem-like properties of GC cells in vitro and in vivo. Moreover, direct injection of Ad-Bmi-1i into xenografts suppressed tumor growth and destroyed cancer cells in vivo. Ad-Bmi-1i inhibited the proliferation of GC cells mainly via inducing senescence in vitro, but it suppressed tumor through inducing senescence and apoptosis, and inhibiting angiogenesis in vivo. Bmi-1 knockdown by Ad-Bmi-1i downregulated VEGF via inhibiting AKT activity. These results suggest that Ad-Bmi-1i not only inhibits tumor growth and stem cell-like phenotype by inducing cellular senescence directly, but also has an indirect anti-tumor activity by anti-angiogenesis effects via regulating PTEN/AKT/VEGF pathway. Transfer of gene interference guided by its own promoter by an adeno-associated virus (AAV) vector might be a potent antitumor approach for cancer therapy. PMID:27009837

  3. The frontal lobes and inhibitory function

    International Nuclear Information System (INIS)

    Konishi, Seiki

    2011-01-01

    Neuropsychological studies using traditional tasks of inhibitory functions, such as the Wisconsin card sorting test (WCST) and the Go/No-Go Task have revealed that the frontal lobe is responsible for several types of inhibitory functions. However, the detailed psychological nature of the inhibitory functions and the precise location of their critical foci within the frontal lobe remain to be investigated. Functional magnetic resonance imaging provides spatial and temporal resolution that allowed us to illuminate at least 4 frontal regions involved in inhibitory functions: the dorsolateral, ventrolateral, and rostral parts of the frontal lobe and the presupplementary motor area (preSMA). The ventrolateral part of the frontal lobe in the right hemisphere was activated during response inhibition. The preSMA in the left hemisphere was activated during inhibition of proactive interference immediately after the dimension changes of the WCST. The rostral part of the frontal lobe in the left hemisphere was activated during inhibition long after the dimension changes. The dorsolateral part of the frontal lobe in the left hemisphere was activated at the dimension changes in the first time, but not in the second time. These findings provide clues to our understanding of functional differentiation of inhibitory functions and their localization in the frontal lobe. (author)

  4. Flexible brain network reconfiguration supporting inhibitory control.

    Science.gov (United States)

    Spielberg, Jeffrey M; Miller, Gregory A; Heller, Wendy; Banich, Marie T

    2015-08-11

    The ability to inhibit distracting stimuli from interfering with goal-directed behavior is crucial for success in most spheres of life. Despite an abundance of studies examining regional brain activation, knowledge of the brain networks involved in inhibitory control remains quite limited. To address this critical gap, we applied graph theory tools to functional magnetic resonance imaging data collected while a large sample of adults (n = 101) performed a color-word Stroop task. Higher demand for inhibitory control was associated with restructuring of the global network into a configuration that was more optimized for specialized processing (functional segregation), more efficient at communicating the output of such processing across the network (functional integration), and more resilient to potential interruption (resilience). In addition, there were regional changes with right inferior frontal sulcus and right anterior insula occupying more central positions as network hubs, and dorsal anterior cingulate cortex becoming more tightly coupled with its regional subnetwork. Given the crucial role of inhibitory control in goal-directed behavior, present findings identifying functional network organization supporting inhibitory control have the potential to provide additional insights into how inhibitory control may break down in a wide variety of individuals with neurological or psychiatric difficulties.

  5. Impact of Power Ultrasound on Antihypertensive Activity, Functional Properties, and Thermal Stability of Rapeseed Protein Hydrolysates

    Directory of Open Access Journals (Sweden)

    Asif Wali

    2017-01-01

    Full Text Available The effects of power ultrasound pretreatments on the degree of hydrolysis (DH, angiotensin-I-converting enzyme (ACE inhibitory activity, amino acid composition, surface hydrophobicity, protein solubility, and thermal stability of ACE inhibition of rapeseed protein hydrolysates were evaluated. Ultrasonic pretreatments before enzymolysis in terms of power and exposure time increased the DH and ACE inhibitory activities over the control (without sonication. In this study, maximum DH 22.07% and ACE inhibitory activity 72.13% were achieved at 600 W and 12 min pretreatment. Compared to the hydrolysates obtained without sonication, the amino acid profile of ultrasound pretreated hydrolysates showed significant changes particularly in the proline content and hydrophobic amino acids with an increased rate of 2.47% and 6.31%, respectively. Ultrasound pretreatment (600 watts, 12 min improved functional properties of protein hydrolysates over control by enhancing surface hydrophobicity and solubility index with an increased rate of 130.76% and 34.22%. Moreover, the stability test showed that the ACE inhibitory activity remains stable against heat treatments. However, extensive heat, prolonged heating time, and alkaline conditions were not in the favor of stability test, while under mild heat and acidic conditions their ACE inhibitory activities were not significantly different from unheated samples.

  6. Three-component synthesis of pyrano[2,3-d]-pyrimidine dione derivatives facilitated by sulfonic acid nanoporous silica (SBA-Pr-SO3H and their docking and urease inhibitory activity

    Directory of Open Access Journals (Sweden)

    Ghodsi Mohammadi Ziarani

    2013-01-01

    Full Text Available A straightforward and efficient method for the synthesis of pyrano[2,3-d]pyrimidine diones derivatives from the reaction of barbituric acid, malononitrile and various aromatic aldehydes using SBA-Pr-SO3H as a nanocatalyst is reported.ResultsReactions proceed with high efficiency under solvent free conditions. Urease inhibitory activity of pyrano[2,3-d]pyrimidine diones derivatives were tested against Jack bean urease using phenol red method. Three compounds of 4a, 4d and 4l were not active in urease inhibition test, but compound 4a displayed slight urease activation properties. Compounds 4b, 4k, 4f, 4e, 4j, 4g and 4c with hydrophobic substitutes on phenyl ring, showed good inhibitory activity (19.45-279.14 muM.DiscussionThe compounds with electron donating group and higher hydrophobic interaction with active site of enzyme prevents hydrolysis of substrate. Electron withdrawing groups such as nitro at different position and meta-methoxy reduced urease inhibitory activity. Substitution of both hydrogen of barbituric acid with methyl group will convert inhibitor to activator.

  7. Three-component synthesis of pyrano[2,3-d]-pyrimidine dione derivatives facilitated by sulfonic acid nanoporous silica (SBA-Pr-SO3H and their docking and urease inhibitory activity

    Directory of Open Access Journals (Sweden)

    Ziarani Ghodsi Mohammadi

    2013-01-01

    Full Text Available Abstract Background A straightforward and efficient method for the synthesis of pyrano[2,3-d]pyrimidine diones derivatives from the reaction of barbituric acid, malononitrile and various aromatic aldehydes using SBA-Pr-SO3H as a nanocatalyst is reported. Results Reactions proceed with high efficiency under solvent free conditions. Urease inhibitory activity of pyrano[2,3-d]pyrimidine diones derivatives were tested against Jack bean urease using phenol red method. Three compounds of 4a, 4d and 4l were not active in urease inhibition test, but compound 4a displayed slight urease activation properties. Compounds 4b, 4k, 4f, 4e, 4j, 4g and 4c with hydrophobic substitutes on phenyl ring, showed good inhibitory activity (19.45-279.14 μM. Discussion The compounds with electron donating group and higher hydrophobic interaction with active site of enzyme prevents hydrolysis of substrate. Electron withdrawing groups such as nitro at different position and meta-methoxy reduced urease inhibitory activity. Substitution of both hydrogen of barbituric acid with methyl group will convert inhibitor to activator.

  8. α-Glucosidase inhibitory activity of selected Malaysian plants

    Directory of Open Access Journals (Sweden)

    Dzatil Awanis Mohd Bukhari

    2017-01-01

    Full Text Available Diabetes is a common metabolic disease indicated by unusually high plasma glucose level that can lead to major complications such as diabetic neuropathy, retinopathy, and cardiovascular diseases. One of the effective therapeutic managements of the disease is to reduce postprandial hyperglycemia through inhibition of α-glucosidase, a carbohydrate-hydrolyzing enzyme to retard overall glucose absorption. In recent years, a plenty of research works have been conducted looking for novel and effective α-glucosidase inhibitors (AGIs from natural sources as alternatives for the synthetic AGI due to their unpleasant side effects. Plants and herbs are rich with secondary metabolites that have massive pharmaceutical potential. Besides, studies showed that phytochemicals such as flavonoids, alkaloids, terpenoids, anthocyanins, glycosides, and phenolic compounds possess significant inhibitory activity against α-glucosidase enzyme. Malaysia is a tropical country that is rich with medicinal herbs. In this review, we focus on eight Malaysian plants with the potential as AGI to develop a potential functional food or lead compounds against diabetes.

  9. α-Glucosidase Inhibitory Activity of Selected Malaysian Plants.

    Science.gov (United States)

    Mohd Bukhari, Dzatil Awanis; Siddiqui, Mohammad Jamshed; Shamsudin, Siti Hadijah; Rahman, Md Mukhlesur; So'ad, Siti Zaiton Mat

    2017-01-01

    Diabetes is a common metabolic disease indicated by unusually high plasma glucose level that can lead to major complications such as diabetic neuropathy, retinopathy, and cardiovascular diseases. One of the effective therapeutic managements of the disease is to reduce postprandial hyperglycemia through inhibition of α-glucosidase, a carbohydrate-hydrolyzing enzyme to retard overall glucose absorption. In recent years, a plenty of research works have been conducted looking for novel and effective α-glucosidase inhibitors (AGIs) from natural sources as alternatives for the synthetic AGI due to their unpleasant side effects. Plants and herbs are rich with secondary metabolites that have massive pharmaceutical potential. Besides, studies showed that phytochemicals such as flavonoids, alkaloids, terpenoids, anthocyanins, glycosides, and phenolic compounds possess significant inhibitory activity against α-glucosidase enzyme. Malaysia is a tropical country that is rich with medicinal herbs. In this review, we focus on eight Malaysian plants with the potential as AGI to develop a potential functional food or lead compounds against diabetes.

  10. An overview of technologies for immobilization of enzymes and surface analysis techniques for immobilized enzymes

    Science.gov (United States)

    Mohamad, Nur Royhaila; Marzuki, Nur Haziqah Che; Buang, Nor Aziah; Huyop, Fahrul; Wahab, Roswanira Abdul

    2015-01-01

    The current demands of sustainable green methodologies have increased the use of enzymatic technology in industrial processes. Employment of enzyme as biocatalysts offers the benefits of mild reaction conditions, biodegradability and catalytic efficiency. The harsh conditions of industrial processes, however, increase propensity of enzyme destabilization, shortening their industrial lifespan. Consequently, the technology of enzyme immobilization provides an effective means to circumvent these concerns by enhancing enzyme catalytic properties and also simplify downstream processing and improve operational stability. There are several techniques used to immobilize the enzymes onto supports which range from reversible physical adsorption and ionic linkages, to the irreversible stable covalent bonds. Such techniques produce immobilized enzymes of varying stability due to changes in the surface microenvironment and degree of multipoint attachment. Hence, it is mandatory to obtain information about the structure of the enzyme protein following interaction with the support surface as well as interactions of the enzymes with other proteins. Characterization technologies at the nanoscale level to study enzymes immobilized on surfaces are crucial to obtain valuable qualitative and quantitative information, including morphological visualization of the immobilized enzymes. These technologies are pertinent to assess efficacy of an immobilization technique and development of future enzyme immobilization strategies. PMID:26019635

  11. Reactivity improvement of cellulolytic enzyme lignin via mild hydrothermal modification.

    Science.gov (United States)

    Ma, Zhuoming; Tang, Jiafa; Li, Shujun; Suo, Enxiang

    2017-12-01

    Isolated by the cellulolytic enzyme lignin (CEL) process, water-alcohol (1:1, v/v) was introduced as co-solvent in the process of the hydrothermal treatment. The modification parameters such as reaction temperature and time, solid-to-liquid ratio, and catalysts (NaOH and NaOAlO 2 ) have been investigated in terms of the specific lignin properties, such as the phenolic hydroxyl content (OH phen ), DPPH free radical scavenging rate, and formaldehyde value. The CELs were also characterized by GPC, FT-IR and 1 H NMR spectroscopy, and Py-GC/MS. The key data are under optimal lignin modification conditions (solid-to-liquid ratio of 1:10 (w/v) and a temperature of 250°C for 60min) are: OH phen content: 2.50mmol/g; half maximal inhibitory concentration (IC 50 ) towards DPPH free radicals: 88.2mg/L; formaldehyde value: 446.9g/kg). Both base catalysts decrease the residue rate, but phenol reactivities of the products were also detracted. Py-GC/MS results revealed that modified lignin had a higher phenolic composition than the CEL did, especially the modified lignin without catalyst (ML), which represented 74.51% phenolic content. Copyright © 2017. Published by Elsevier Inc.

  12. Organizers of inhibitory synapses come of age.

    Science.gov (United States)

    Krueger-Burg, Dilja; Papadopoulos, Theofilos; Brose, Nils

    2017-08-01

    While the postsynaptic density of excitatory synapses is known to encompass a highly complex molecular machinery, the equivalent organizational structure of inhibitory synapses has long remained largely undefined. In recent years, however, substantial progress has been made towards identifying the full complement of organizational proteins present at inhibitory synapses, including submembranous scaffolds, intracellular signaling proteins, transsynaptic adhesion proteins, and secreted factors. Here, we summarize these findings and discuss future challenges in assigning synapse-specific functions to the newly discovered catalog of proteins, an endeavor that will depend heavily on newly developed technologies such as proximity biotinylation. Further advances are made all the more essential by growing evidence that links inhibitory synapses to psychiatric and neurological disorders. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Bilingual Contexts Modulate the Inhibitory Control Network

    Directory of Open Access Journals (Sweden)

    Jing Yang

    2018-03-01

    Full Text Available The present functional magnetic resonance imaging (fMRI study investigated influences of language contexts on inhibitory control and the underlying neural processes. Thirty Cantonese–Mandarin–English trilingual speakers, who were highly proficient in Cantonese (L1 and Mandarin (L2, and moderately proficient in English (L3, performed a picture-naming task in three dual-language contexts (L1-L2, L2-L3, and L1-L3. After each of the three naming tasks, participants performed a flanker task, measuring contextual effects on the inhibitory control system. Behavioral results showed a typical flanker effect in the L2-L3 and L1-L3 condition, but not in the L1-L2 condition, which indicates contextual facilitation on inhibitory control performance by the L1-L2 context. Whole brain analysis of the fMRI data acquired during the flanker tasks showed more neural activations in the right prefrontal cortex and subcortical areas in the L2-L3 and L1-L3 condition on one hand as compared to the L1-L2 condition on the other hand, suggesting greater involvement of the cognitive control areas when participants were performing the flanker task in L2-L3 and L1-L3 contexts. Effective connectivity analyses displayed a cortical-subcortical-cerebellar circuitry for inhibitory control in the trilinguals. However, contrary to the right-lateralized network in the L1-L2 condition, functional networks for inhibitory control in the L2-L3 and L1-L3 condition are less integrated and more left-lateralized. These findings provide a novel perspective for investigating the interaction between bilingualism (multilingualism and inhibitory control by demonstrating instant behavioral effects and neural plasticity as a function of changes in global language contexts.

  14. Mechanical properties of the compass depressors of the sea-urchin Paracentrotus lividus (Echinodermata, Echinoidea and the effects of enzymes, neurotransmitters and synthetic tensilin-like protein.

    Directory of Open Access Journals (Sweden)

    Iain C Wilkie

    Full Text Available The compass depressors (CDs of the sea-urchin lantern are ligaments consisting mainly of discontinuous collagen fibrils associated with a small population of myocytes. They are mutable collagenous structures, which can change their mechanical properties rapidly and reversibly under nervous control. The aims of this investigation were to characterise the baseline (i.e. unmanipulated static mechanical properties of the CDs of Paracentrotus lividus by means of creep tests and incremental force-extension tests, and to determine the effects on their mechanical behaviour of a range of agents. Under constant load the CDs exhibited a three-phase creep curve, the mean coefficient of viscosity being 561±365 MPa.s. The stress-strain curve showed toe, linear and yield regions; the mean strain at the toe-linear inflection was 0.86±0.61; the mean Young's modulus was 18.62±10.30 MPa; and the mean tensile strength was 8.14±5.73 MPa. Hyaluronidase from Streptomyces hyalurolyticus had no effect on creep behaviour, whilst chondroitinase ABC prolonged primary creep but had no effect on secondary creep or on any force-extension parameters; it thus appears that neither hyaluronic acid nor sulphated glycosaminoglycans have an interfibrillar load transfer function in the CD. Acetylcholine, the muscarinic agonists arecoline and methacholine, and the nicotinic agonists nicotine and 1-[1-(3,4-dimethyl-phenyl-ethyl]-piperazine produced an abrupt increase in CD viscosity; the CDs were not differentially sensitive to muscarinic or nicotinic agonists. CDs showed either no, or no consistent, response to adrenaline, L-glutamic acid, 5-hydroxytryptamine and γ-aminobutyric acid. Synthetic echinoid tensilin-like protein had a weak and inconsistent stiffening effect, indicating that, in contrast to holothurian tensilins, the echinoid molecule may not be involved in the regulation of collagenous tissue tensility. We compare in detail the mechanical behaviour of the CD with that

  15. Curious Cases of the Enzymes.

    Science.gov (United States)

    Ulusu, Nuriye Nuray

    2015-07-01

    Life as we know it heavily relies on biological catalysis, in fact, in a very nonromantic version of it, life could be considered as a series of chemical reactions, regulated by the guarding principles of thermodynamics. In ancient times, a beating heart was a good sign of vitality, however, to me, it is actually the presence of active enzymes that counts… Though we do not usually pay attention, the history of enzymology is as old as humanity itself, and dates back to the ancient times. This paper is dedicated to these early moments of this remarkable science that touched our lives in the past and will make life a lot more efficient for humanity in the future. There was almost always a delicate, fundamentally essential relationship between mankind and the enzymes. Challenged by a very alien and hostile Nature full of predators, prehistoric men soon discovered the medicinal properties of the plants, through trial and error. In fact, they accidently discovered the enzyme inhibitors and thus, in crude terms, kindled a sparkling area of research. These plant-derivatives that acted as enzyme inhibitors helped prehistoric men in their pursuit of survival and protection from predators; in hunting and fishing… Later in history, while the underlying purposes of survival and increasing the quality of life stayed intact, the ways and means of enzymology experienced a massive transformation, as the 'trial and error' methodology of the ancients is now replaced with rational scientific theories.

  16. Monoamine Oxidase Inhibitory Constituents of Propolis: Kinetics and Mechanism of Inhibition of Recombinant Human MAO-A and MAO-B

    Directory of Open Access Journals (Sweden)

    Narayan D. Chaurasiya

    2014-11-01

    Full Text Available Propolis is the resinous material that bees gather from leaf buds, flowers and vegetables. Propolis extracts contain constituents with a broad spectra of pharmacological properties and are important ingredients of popular dietary supplements. Propolis extracts were evaluated in vitro for inhibition of recombinant human monoamine oxidase (MAO-A and MAO-B. The dichloromethane extract of propolis showed potent inhibition of human MAO-A and MAO-B. Further fractionation identified the most active fractions as rich in flavonoids. Galangin and apigenin were identified as the principal MAO-inhibitory constituents. Inhibition of MAO-A by galangin was about 36 times more selective than MAO-B, while apigenin selectivity for MAO-A vs. MAO-B was about 1.7 fold. Apigenin inhibited MAO-B significantly more potently than galangin. Galangin and apigenin were further evaluated for kinetic characteristics and the mechanism for the enzymes’ inhibition. Binding of galangin and apigenin with MAO-A and -B was not time-dependent and was reversible, as suggested by enzyme-inhibitor binding and dissociation-dialysis assay. The inhibition kinetics studies suggested that galangin and apigenin inhibited MAO-A and -B by a competitive mechanism. Presence of prominent MAO inhibitory constituents in propolis products suggests their potential for eliciting pharmacological effects that might be useful in depression or other neurological disorders. The results may also have important implications in drug-dietary supplement interactions.

  17. Chinese medicinal formula Fufang Xueshuantong capsule could inhibit the activity of angiotensin converting enzyme

    Science.gov (United States)

    Sheng, Shujing; Wang, Yonggang; Long, Chaofeng; Su, Weiwei; Rong, Xia

    2014-01-01

    Fufang Xueshuantong (FXST) capsule, a Chinese medicinal formula composed of four herbals – Panax notoginseng, Radix Astragali, Radix Salvia Miltiorrhizae and Radix Scrophulariaceae, has been used to treat cardiovascular diseases for many years, but the pharmacological mechanisms underlying its effects has not been clarified. This study investigates if a connection between FXST and angiotensin converting enzyme (ACE) might be an explanation for its pharmacological effects. ACE inhibition assay was performed on FXST capsule, 50% ethanol extracts from the four herbals and three selected saponins most abundant in P. notoginseng (Ginsenoside Rg1, Ginsenoside Rb1 and Notoginsenoside R1) using a biochemical test. Reversed-phase high-performance liquid chromatography of liberated hippuric acid from the ACE assay was conducted to determine the inhibitory effect. As a result, FXST and extracts from P. notoginseng showed a significant and dose-dependent inhibition on ACE activity with the IC50 values of 115 μg/ml and 179 μg/ml, respectively. But extracts from the other three herbals and the three selected saponins had no significant effect on ACE inhibition. Compared to other reported plant extracts, FXST could be considered as an effective ACE inhibitor. The inhibition of ACE activity supports the traditional use of FXST on blood circulation and the inhibitory property of FXST is mainly caused by P. notoginseng. PMID:26019516

  18. Enzymes for improved biomass conversion

    Science.gov (United States)

    Brunecky, Roman; Himmel, Michael E.

    2016-02-02

    Disclosed herein are enzymes and combinations of the enzymes useful for the hydrolysis of cellulose and the conversion of biomass. Methods of degrading cellulose and biomass using enzymes and cocktails of enzymes are also disclosed.

  19. The disulfide-rich Metridia luciferase refolded from E. coli inclusion bodies reveals the properties of a native folded enzyme produced in insect cells.

    Science.gov (United States)

    Markova, Svetlana V; Larionova, Marina D; Gorbunova, Darya A; Vysotski, Eugene S

    2017-10-01

    The bioluminescence of a marine copepod Metridia longa is determined by a small secreted coelenterazine-dependent luciferase that uses coelenterazine as a substrate of enzymatic reaction to generate light (λ max =480nm). To date, four different isoforms of the luciferase differing in size, sequences, and properties have been cloned by functional screening. All of them contain ten conserved Cys residues that suggests up to five SS intramolecular bonds per luciferase molecule. Whereas the use of copepod luciferases as bioluminescent reporters in biomedical research in vivo is growing from year to year, their application for in vitro assays is still limited by the difficulty in obtaining significant amounts of luciferase. The most cost-effective host for producing recombinant proteins is Escherichia coli. However, prokaryotic and eukaryotic cells maintain the reductive environment in cytoplasm that hinders the disulfide bond formation and consequently the proper folding of luciferase. Here we report the expression of the MLuc7 isoform of M. longa luciferase in E. coli cells and the efficient procedure for refolding from inclusion bodies yielding a high-active monomeric protein. Furthermore, in a set of identical experiments we demonstrate that bioluminescent and structural features of MLuc7 produced in bacterial cells are identical to those of MLuc7 isoform produced from culture medium of insect cells. Although the yield of high-purity protein is only 6mg/L, the application of E. coli cells to produce the luciferase is simpler and more cost-effective than the use of insect cells. We expect that the suggested technology of Metridia luciferase production allows obtaining of sufficient amounts of protein both for the development of novel in vitro analytical assays with the use of MLuc7 as a label and for structural studies. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Investigating the Antioxidant Properties of Royal Jelly and Vitamin C on Enzymes, Histomorphometric and Liver Cells Apoptosis in Mice Suffering Hemolytic Anemia

    Directory of Open Access Journals (Sweden)

    Hojat Anbara

    2016-09-01

    Full Text Available Background & Objective: Hemolytic anemia induced by phenylhydrazine (PHZ as a hemolytic composition can change the function and structure of liver. Therefore, the present study attempts to evaluate the protective effects of vitamin C and royal jelly co-administration against the oxidative damages and liver apoptosis induced by hemolytic anemia in adult mice. Materials & Methods: 32 adult male mice were divided equally and randomly into four groups. The first group received normal saline with a dose of 0.1 ml, IP. The second group received a dose of vitamin C (250 kg/mg, IP along with 100 kg/mg dose of royal jelly administered orally. The third group was administered with 6 mg/100 gr, IP phenylhydrazine in 48 hour intervals. Finally, the fourth group received vitamin C and royal jelly in the doses similar to the first three groups along with phenylhydrazine with the same doses of previous groups. After 35 days, the serum and testis samples were taken and were used for serum analysis and histochemical and histomorphometric studies. Results: Phenylhydrazine increased the level of serum concentration of aspartate transaminase, alkaline phosphatase, alanine transaminase, malondialdehyde and lactate dehydrogenase and decreased the superoxide dismutase along with the total antioxidant capacity and serum albumin. Moreover, phenylhydrazine increased the apoptosis, the number of kupffer cells and the diameter of hepatocytes. Prescribing the royal jelly with vitamin C improved the changes of abovementioned parameters significantly. Conclusion: Royal jelly with vitamin C is an antioxidant with the potential properties in preventing the oxidative damages and apoptosis induced by phenylhydrazine-induced hemolytic anemia in mouse liver.

  1. Nutritional supplements modulate fluorescent protein-bound advanced glycation endproducts and digestive enzymes related to type 2 diabetes mellitus.

    Science.gov (United States)

    Koch, Emily R; Deo, Permal

    2016-09-01

    Chronic hyperglycemia enhances the formation of advanced glycation endproducts (AGEs) and reactive oxygen species (ROS), contributing to diabetic complications. Thus, controlling blood glucose levels, inhibiting the formation of AGEs and reducing ROS are key therapeutic targets in early stage type 2 diabetes. The inhibitory effects of seven commercial liquid nutritional supplements against carbohydrate hydrolysing enzymes, α-amylase and α-glucosidase, was determined by dinitrosalicylic (DNS) reagent and p-nitrophenyl-α-D-glucopyranoside solution, respectively. Antiglycation activity was determined using the formation of fluorescent protein-bound AGEs. Total phenolic and flavonoid content and antioxidant properties (1,1-diphenyl-2-picrylhydrazyl antioxidant activity (DPPH) and ferric reducing antioxidant power (FRAP)) were determined for correlation among these components and inhibitory activities. Samoan noni juice showed the greatest inhibitory effects against α-amylase, whereas chlorophyll extracts showed the greatest inhibitory effect against α-glucosidase. Inhibition of α-glucosidase correlated with TFC (r(2) = 0.766; p 1) and FRAP (r(2) = 0.750; p 1) whereas no correlation was observed for α-amylase inhibition. All supplements inhibited fluorescent protein-bound AGEs, with the greatest effect exerted by Olive Leaf Extract, Blood Sugar Support (IC50 = 0.5 mg/ml). The IC50 values negatively correlated with TPC (r(2) = -0.707; p 1) and DPPH scavenging activities (r(2) = 0.515; p nutritional supplements in managing and treating type 2 diabetes mellitus.

  2. Inhibition of Human Cytochrome P450 Enzymes by Allergen Removed Rhus verniciflua Stoke Standardized Extract and Constituents

    Directory of Open Access Journals (Sweden)

    Hyunsik Jung

    2014-01-01

    Full Text Available Objective. Potential interactions between herbal extracts and the cytochrome P450 (CYP system lead to serious adverse events or decreased drug efficacy. Rhus verniciflua stoke (RVS and its constituents have been reported to have various pharmacological properties. We evaluated the inhibitory potential of RVS and its constituents on the major CYP isoforms. Methods. The effects of allergen removed RVS (aRVS standardized extract and major components, fustin and fisetin isolated from aRVS, were evaluated on CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4 isoenzyme activity by a luminescent CYP recombinant human enzyme assay. Results. The aRVS extract showed relative potent inhibitory effects on the CYP2C9 (IC50, <0.001 μg/mL, CYP2C19 (IC50, 9.68 μg/mL, and CYP1A2 (IC50, 10.0 μg/mL. However, it showed weak inhibition on CYP3A4 and CYP2D6. Fustin showed moderate inhibitory effects on the CYP2C19 (IC50, 64.3 μg/mL and weak inhibition of the other CYP isoforms similar to aRVS. Fisetin showed potent inhibitory effects on CYP2C9, CYP2C19, and CYP1A2. Fisetin showed moderate inhibition of CYP2D6 and weak inhibition of CYP3A4. Conclusions. These results indicate that aRVS, a clinically available herbal medicine, could contribute to herb-drug interactions when orally coadministered with drugs metabolized by CYP2C9, CYP2C19, and CYP1A2.

  3. Immobilized enzymes and cells

    Energy Technology Data Exchange (ETDEWEB)

    Bucke, C; Wiseman, A

    1981-04-04

    This article reviews the current state of the art of enzyme and cell immobilization and suggests advances which might be made during the 1980's. Current uses of immobilized enzymes include the use of glucoamylase in the production of glucose syrups from starch and glucose isomerase in the production of high fructose corn syrup. Possibilities for future uses of immobilized enzymes and cells include the utilization of whey and the production of ethanol.

  4. Profiling the orphan enzymes

    Science.gov (United States)

    2014-01-01

    The emergence of Next Generation Sequencing generates an incredible amount of sequence and great potential for new enzyme discovery. Despite this huge amount of data and the profusion of bioinformatic methods for function prediction, a large part of known enzyme activities is still lacking an associated protein sequence. These particular activities are called “orphan enzymes”. The present review proposes an update of previous surveys on orphan enzymes by mining the current content of public databases. While the percentage of orphan enzyme activities has decreased from 38% to 22% in ten years, there are still more than 1,000 orphans among the 5,000 entries of the Enzyme Commission (EC) classification. Taking into account all the reactions present in metabolic databases, this proportion dramatically increases to reach nearly 50% of orphans and many of them are not associated to a known pathway. We extended our survey to “local orphan enzymes” that are activities which have no representative sequence in a given clade, but have at least one in organisms belonging to other clades. We observe an important bias in Archaea and find that in general more than 30% of the EC activities have incomplete sequence information in at least one superkingdom. To estimate if candidate proteins for local orphans could be retrieved by homology search, we applied a simple strategy based on the PRIAM software and noticed that candidates may be proposed for an important fraction of local orphan enzymes. Finally, by studying relation between protein domains and catalyzed activities, it appears that newly discovered enzymes are mostly associated with already known enzyme domains. Thus, the exploration of the promiscuity and the multifunctional aspect of known enzyme families may solve part of the orphan enzyme issue. We conclude this review with a presentation of recent initiatives in finding proteins for orphan enzymes and in extending the enzyme world by the discovery of new

  5. Phenotypic characterisation and assessment of the inhibitory ...

    African Journals Online (AJOL)

    Six strains of Lactobacillus spp. were isolated from fermenting corn slurry, fresh cow milk, and the faeces of pig, albino rat, and human infant. Their inhibitory action was tested against some spoilage and pathogenic bacteria. Lactobacillus acidophilus isolated from milk was found to display a higher antagonistic effect with ...

  6. Phenotypic characterisation and assessment of the inhibitory ...

    African Journals Online (AJOL)

    Fred

    inhibitory potential of Lactobacillus isolates from different sources. Oyetayo, V.O.. Department of ... Six strains of Lactobacillus spp. were isolated from fermenting corn slurry, fresh cow milk, and the faeces of pig, albino rat, and human ... the growth of some pathogens by Lactobacillus reuteri BSA 13, obtained from pig faeces.

  7. Inhibitory ability of children with developmental dyscalculia.

    Science.gov (United States)

    Zhang, Huaiying; Wu, Hanrong

    2011-02-01

    Inhibitory ability of children with developmental dyscalculia (DD) was investigated to explore the cognitive mechanism underlying DD. According to the definition of developmental dyscalculia, 19 children with DD-only and 10 children with DD&RD (DD combined with reading disability) were selected step by step, children in two control groups were matched with children in case groups by gender and age, and the match ratio was 1:1. Psychological testing software named DMDX was used to measure inhibitory ability of the subjects. The differences of reaction time in number Stroop tasks and differences of accuracy in incongruent condition of color-word Stroop tasks and object inhibition tasks between DD-only children and their controls reached significant levels (P<0.05), and the differences of reaction time in number Stroop tasks between dyscalculic and normal children did not disappear after controlling the non-executive components. The difference of accuracy in color-word incongruent tasks between children with DD&RD and normal children reached significant levels (P<0.05). Children with DD-only confronted with general inhibitory deficits, while children with DD&RD confronted with word inhibitory deficits only.

  8. Inhibitory Effect of Gamma-Irradiated Chitosan on the Growth of Denitrifiers

    Directory of Open Access Journals (Sweden)

    Javier Vilcáez

    2009-01-01

    Full Text Available In order to find an environmentally benign substitute to hazardous inhibitory agents, the inhibitory effect of -irradiated chitosans against a mixed culture of denitrifying bacteria was experimentally evaluated. Unlike other studies using pure aerobic cultures, the observed effect was not a complete inhibition but a transient inhibition reflected by prolonged lag phases and reduced growth rates. Raw chitosan under acid conditions (pH 6.3 exerted the strongest inhibition followed by the 100 kGy and 500 kGy irradiated chitosans, respectively. Therefore, because the molecular weight of chitosan decreases with the degree of -irradiation, the inhibitory properties of chitosan due to its high molecular weight were more relevant than the inhibitory properties gained due to the modification of the surface charge and/or chemical structure by -irradiation. High dosage of -irradiated appeared to increase the growth of mixed denitrifying bacteria in acid pH media. However, in neutral pH media, high dosage of -irradiation appeared to enhance the inhibitory effect of chitosan.

  9. In vitro inhibition activity of polyphenol-rich extracts from Syzygium aromaticum (L.) Merr. & Perry (Clove) buds against carbohydrate hydrolyzing enzymes linked to type 2 diabetes and Fe(2+)-induced lipid peroxidation in rat pancreas.

    Science.gov (United States)

    Adefegha, Stephen Adeniyi; Oboh, Ganiyu

    2012-10-01

    To investigate and compare the inhibitory properties of free and bound phenolic extracts of clove bud against carbohydrate hydrolyzing enzymes (alpha-amylase & alpha-glucosidase) and Fe(2+)-induced lipid peroxidation in rat pancreas in vitro. The free phenolics were extracted with 80% (v/v) acetone, while bound phenolics were extracted from the alkaline and acid hydrolyzed residue with ethyl acetate. Then, the interaction of the extracts with alpha-amylase and alpha-glucosidase was subsequently assessed. Thereafter, the total phenolic contents and antioxidant activities of the extracts were determined. The result revealed that both extracts inhibited alpha-amylase and alpha-glucosidase in a dose-dependent manner. However, the alpha-glucosidase inhibitory activity of the extracts were significantly (Ppancreas in vitro. This study provides a biochemical rationale by which clove elicits therapeutic effect on type 2 diabetes.

  10. New Indole Alkaloids from the Bark of Rauvolfia Reflexa and their Cholinesterase Inhibitory Activity

    Directory of Open Access Journals (Sweden)

    Mehran Fadaeinasab

    2015-11-01

    Full Text Available Background/Aims: Rauvolfia reflexa is a member of the Apocynaceae family. Plants from the Apocynaceae family have been traditionally used in the treatment of age-related brain disorders Methods and Results: Two new indole alkaloids, rauvolfine C (1 and 3-methyl-10,11-dimethoxy-6-methoxycarbonyl-β-carboline (2, along with five known, macusine B (3, vinorine (4, undulifoline (5, isoresrpiline (6 and rescinnamine (7 were isolated from the bark of Rauvolfia reflexa. Cholinesterase inhibitory assay and molecular docking were performed to get insight of the inhibitory activity and molecular interactions of the compounds. The compounds showed good to moderate cholinesterase inhibitory activity with IC50 values in the range of 8.06 to 73.23 µM. Compound 7 was found to be the most potent inhibitor of both acetylcholinesterase (AChE and butyrylcholinesterase (BChE. Compounds 1, 2, 5 and 6 were found to be selective towards BChE, while compounds 3, 4 and 7 were dual inhibitors, having almost equal inhibitory activity on both AChE and BChE. Molecular docking revealed that compounds 6 and 7 interacted differently on AChE and BChE, by means of hydrophobic interactions and hydrogen bonding. In AChE, the indole moiety of both compounds interacted with the residues lining the peripheral anionic site, whereas in BChE, their methoxy groups are primarily responsible for the strong inhibitory activity via interactions with residues at the active site of the enzyme. Conclusion: Two new and five known indole alkaloids were isolated from R. reflexa. Among the compounds, 7 and 6 showed the most potent and promising cholinesterase inhibitory activity, worthy for further investigations.

  11. New Indole Alkaloids from the Bark of Rauvolfia Reflexa and their Cholinesterase Inhibitory Activity.

    Science.gov (United States)

    Fadaeinasab, Mehran; Basiri, Alireza; Kia, Yalda; Karimian, Hamed; Ali, Hapipah Mohd; Murugaiyah, Vikneswaran

    2015-01-01

    Rauvolfia reflexa is a member of the Apocynaceae family. Plants from the Apocynaceae family have been traditionally used in the treatment of age-related brain disorders Methods and Results: Two new indole alkaloids, rauvolfine C (1) and 3-methyl-10,11-dimethoxy-6-methoxycarbonyl-β-carboline (2), along with five known, macusine B (3), vinorine (4), undulifoline (5), isoresrpiline (6) and rescinnamine (7) were isolated from the bark of Rauvolfia reflexa. Cholinesterase inhibitory assay and molecular docking were performed to get insight of the inhibitory activity and molecular interactions of the compounds. The compounds showed good to moderate cholinesterase inhibitory activity with IC50 values in the range of 8.06 to 73.23 µM. Compound 7 was found to be the most potent inhibitor of both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Compounds 1, 2, 5 and 6 were found to be selective towards BChE, while compounds 3, 4 and 7 were dual inhibitors, having almost equal inhibitory activity on both AChE and BChE. Molecular docking revealed that compounds 6 and 7 interacted differently on AChE and BChE, by means of hydrophobic interactions and hydrogen bonding. In AChE, the indole moiety of both compounds interacted with the residues lining the peripheral anionic site, whereas in BChE, their methoxy groups are primarily responsible for the strong inhibitory activity via interactions with residues at the active site of the enzyme. Two new and five known indole alkaloids were isolated from R. reflexa. Among the compounds, 7 and 6 showed the most potent and promising cholinesterase inhibitory activity, worthy for further investigations. © 2015 S. Karger AG, Basel.

  12. Enzyme Engineering for In Situ Immobilization.

    Science.gov (United States)

    Rehm, Fabian B H; Chen, Shuxiong; Rehm, Bernd H A

    2016-10-14

    Enzymes are used as biocatalysts in a vast range of industrial applications. Immobilization of enzymes to solid supports or their self-assembly into insoluble particles enhances their applicability by strongly improving properties such as stability in changing environments, re-usability and applicability in continuous biocatalytic processes. The possibility of co-immobilizing various functionally related enzymes involved in multistep synthesis, conversion or degradation reactions enables the design of multifunctional biocatalyst with enhanced performance compared to their soluble counterparts. This review provides a brief overview of up-to-date in vitro immobilization strategies while focusing on recent advances in enzyme engineering towards in situ self-assembly into insoluble particles. In situ self-assembly approaches include the bioengineering of bacteria to abundantly form enzymatically active inclusion bodies such as enzyme inclusions or enzyme-coated polyhydroxyalkanoate granules. These one-step production strategies for immobilized enzymes avoid prefabrication of the carrier as well as chemical cross-linking or attachment to a support material while the controlled oriented display strongly enhances the fraction of accessible catalytic sites and hence functional enzymes.

  13. Property.

    Science.gov (United States)

    Piele, Philip K.

    Numerous cases in this year's chapter dealt with the same topics of previous years--contracts and bids for building construction, and detachment and annexation of a portion of a school district. The courts continued to attribute board discretionary authority to school boards in school property matters. Intergovernmental disputes over ownership or…

  14. Leukemia inhibitory factor tips the immune balance towards regulatory T cells in multiple sclerosis

    NARCIS (Netherlands)

    Janssens, K.; Van den Haute, C.; Baekelandt, V.; Lucas, S.; van Horssen, J.; Somers, V.; Van Wijmeersch, B.; Stinissen, P.; Hendriks, J.J.A.; Slaets, H.; Hellings, N.

    2015-01-01

    Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS), for which current treatments are unable to prevent disease progression. Based on its neuroprotective and neuroregenerating properties, leukemia inhibitory factor (LIF), a member of the interleukin-6

  15. Artificial Enzymes, "Chemzymes"

    DEFF Research Database (Denmark)

    Bjerre, Jeannette; Rousseau, Cyril Andre Raphaël; Pedersen, Lavinia Georgeta M

    2008-01-01

    Enzymes have fascinated scientists since their discovery and, over some decades, one aim in organic chemistry has been the creation of molecules that mimic the active sites of enzymes and promote catalysis. Nevertheless, even today, there are relatively few examples of enzyme models that successf......Enzymes have fascinated scientists since their discovery and, over some decades, one aim in organic chemistry has been the creation of molecules that mimic the active sites of enzymes and promote catalysis. Nevertheless, even today, there are relatively few examples of enzyme models...... that successfully perform Michaelis-Menten catalysis under enzymatic conditions (i.e., aqueous medium, neutral pH, ambient temperature) and for those that do, very high rate accelerations are seldomly seen. This review will provide a brief summary of the recent developments in artificial enzymes, so called...... "Chemzymes", based on cyclodextrins and other molecules. Only the chemzymes that have shown enzyme-like activity that has been quantified by different methods will be mentioned. This review will summarize the work done in the field of artificial glycosidases, oxidases, epoxidases, and esterases, as well...

  16. Targeted enzyme prodrug therapies.

    Science.gov (United States)

    Schellmann, N; Deckert, P M; Bachran, D; Fuchs, H; Bachran, C

    2010-09-01

    The cure of cancer is still a formidable challenge in medical science. Long-known modalities including surgery, chemotherapy and radiotherapy are successful in a number of cases; however, invasive, metastasized and inaccessible tumors still pose an unresolved and ongoing problem. Targeted therapies designed to locate, detect and specifically kill tumor cells have been developed in the past three decades as an alternative to treat troublesome cancers. Most of these therapies are either based on antibody-dependent cellular cytotoxicity, targeted delivery of cytotoxic drugs or tumor site-specific activation of prodrugs. The latter is a two-step procedure. In the first step, a selected enzyme is accumulated in the tumor by guiding the enzyme or its gene to the neoplastic cells. In the second step, a harmless prodrug is applied and specifically converted by this enzyme into a cytotoxic drug only at the tumor site. A number of targeting systems, enzymes and prodrugs were investigated and improved since the concept was first envisioned in 1974. This review presents a concise overview on the history and latest developments in targeted therapies for cancer treatment. We cover the relevant technologies such as antibody-directed enzyme prodrug therapy (ADEPT), gene-directed enzyme prodrug therapy (GDEPT) as well as related therapies such as clostridial- (CDEPT) and polymer-directed enzyme prodrug therapy (PDEPT) with emphasis on prodrug-converting enzymes, prodrugs and drugs.

  17. Enzymes in Fermented Fish.

    Science.gov (United States)

    Giyatmi; Irianto, H E

    Fermented fish products are very popular particularly in Southeast Asian countries. These products have unique characteristics, especially in terms of aroma, flavor, and texture developing during fermentation process. Proteolytic enzymes have a main role in hydrolyzing protein into simpler compounds. Fermentation process of fish relies both on naturally occurring enzymes (in the muscle or the intestinal tract) as well as bacteria. Fermented fish products processed using the whole fish show a different characteristic compared to those prepared from headed and gutted fish. Endogenous enzymes like trypsin, chymotrypsin, elastase, and aminopeptidase are the most involved in the fermentation process. Muscle tissue enzymes like cathepsins, peptidases, transaminases, amidases, amino acid decarboxylases, glutamic dehydrogenases, and related enzymes may also play a role in fish fermentation. Due to the decreased bacterial number during fermentation, contribution of microbial enzymes to proteolysis may be expected prior to salting of fish. Commercial enzymes are supplemented during processing for specific purposes, such as quality improvement and process acceleration. In the case of fish sauce, efforts to accelerate fermentation process and to improve product quality have been studied by addition of enzymes such as papain, bromelain, trypsin, pepsin, and chymotrypsin. © 2017 Elsevier Inc. All rights reserved.

  18. Inhibitory effects of chickpea and Tribulus terrestris on lipase, α-amylase and α-glucosidase.

    Science.gov (United States)

    Ercan, Pınar; El, Sedef Nehir

    2016-08-15

    The total saponin content and its in vitro bioaccessibilities in Tribulus terrestris and chickpea were determined by a static in vitro digestion method (COST FA1005 Action INFOGEST). Also, in vitro inhibitory effects of the chosen food samples on lipid and starch digestive enzymes were determined by evaluating the lipase, α-amylase and α-glucosidase activities. The tested T. terrestris and chickpea showed inhibitory activity against α-glucosidase (IC50 6967 ± 343 and 2885 ± 85.4 μg/ml, respectively) and α-amylase (IC50 343 ± 26.2 and 167 ± 6.12 μg/ml, respectively). The inhibitory activities of T. terrestris and chickpea against lipase were 15.3 ± 2.03 and 9.74 ± 1.09 μg/ml, respectively. The present study provides the first evidence that these food samples (T. terrestris, chickpea) are potent inhibitors of key enzymes in digestion of carbohydrates and lipids in vitro. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Effects of Neuromodulation on Excitatory-Inhibitory Neural Network Dynamics Depend on Network Connectivity Structure

    Science.gov (United States)

    Rich, Scott; Zochowski, Michal; Booth, Victoria

    2018-01-01

    Acetylcholine (ACh), one of the brain's most potent neuromodulators, can affect intrinsic neuron properties through blockade of an M-type potassium current. The effect of ACh on excitatory and inhibitory cells with this potassium channel modulates their membrane excitability, which in turn affects their tendency to synchronize in networks. Here, we study the resulting changes in dynamics in networks with inter-connected excitatory and inhibitory populations (E-I networks), which are ubiquitous in the brain. Utilizing biophysical models of E-I networks, we analyze how the network connectivity structure in terms of synaptic connectivity alters the influence of ACh on the generation of synchronous excitatory bursting. We investigate networks containing all combinations of excitatory and inhibitory cells with high (Type I properties) or low (Type II properties) modulatory tone. To vary network connectivity structure, we focus on the effects of the strengths of inter-connections between excitatory and inhibitory cells (E-I synapses and I-E synapses), and the strengths of intra-connections among excitatory cells (E-E synapses) and among inhibitory cells (I-I synapses). We show that the presence of ACh may or may not affect the generation of network synchrony depending on the network connectivity. Specifically, strong network inter-connectivity induces synchronous excitatory bursting regardless of the cellular propensity for synchronization, which aligns with predictions of the PING model. However, when a network's intra-connectivity dominates its inter-connectivity, the propensity for synchrony of either inhibitory or excitatory cells can determine the generation of network-wide bursting.

  20. Effects of Different Working Modes of Ultrasound on Structural Characteristics of Zein and ACE Inhibitory Activity of Hydrolysates

    Directory of Open Access Journals (Sweden)

    Xiaofeng Ren

    2017-01-01

    Full Text Available Ultrasound was used as a new technology to pretreat protein prior to proteolysis to improve enzymolysis efficiency. The effects of different working modes of ultrasound on the angiotensin I-converting enzyme (ACE inhibitory activity of zein hydrolysates and the structural characteristics of zein were investigated. The solubility, surface hydrophobicity (H0, ultraviolet-visible (UV-Vis spectra, intrinsic fluorescence spectra, and circular dichroism (CD spectra of zein pretreated with ultrasound were determined. All ultrasound pretreatments significantly improved the ACE inhibitory activity of zein hydrolysates (p<0.05. The highest ACE inhibitory activity, representing an increase of 99.21% over the control, was obtained with dual sweeping frequency ultrasound of 33±2 and 68±2 kHz. The effects of single sweeping frequency and dual fixed frequency ultrasound were stronger than those of single fixed frequency ultrasound for improving the ACE inhibitory activity of zein. Structural changes in zein were induced by ultrasound, as confirmed by changes in the solubility, H0, UV-Vis spectra, intrinsic fluorescence spectra, and CD spectra of zein, and these were consistent with the corresponding ACE inhibitory activities of zein hydrolysates. Thus, ultrasound working mode and frequency have significant effects on the structure of zein and the ACE inhibitory activity of zein hydrolysates.

  1. Lactoferricin-related peptides with inhibitory effects on ACE-dependent vasoconstriction.

    Science.gov (United States)

    Centeno, José M; Burguete, María C; Castelló-Ruiz, María; Enrique, María; Vallés, Salvador; Salom, Juan B; Torregrosa, Germán; Marcos, José F; Alborch, Enrique; Manzanares, Paloma

    2006-07-26

    A selection of lactoferricin B (LfcinB)-related peptides with an angiotensin I-converting enzyme (ACE) inhibitory effect have been examined using in vitro and ex vivo functional assays. Peptides that were analyzed included a set of sequence-related antimicrobial hexapeptides previously reported and two representative LfcinB-derived peptides. In vitro assays using hippuryl-L-histidyl-L-leucine (HHL) and angiotensin I as substrates allowed us to select two hexapeptides, PACEI32 (Ac-RKWHFW-NH2) and PACEI34 (Ac-RKWLFW-NH2), and also a LfcinB-derived peptide, LfcinB17-31 (Ac-FKCRRWQWRMKKLGA-NH2). Ex vivo functional assays using rabbit carotid arterial segments showed PACEI32 (both D- and L-enantiomers) and LfcinB17-31 have inhibitory effects on ACE-dependent angiotensin I-induced contraction. None of the peptides exhibited in vitro ACE inhibitory activity using bradykinin as the substrate. In conclusion, three bioactive lactoferricin-related peptides exhibit inhibitory effects on both ACE activity and ACE-dependent vasoconstriction with potential to modulate hypertension that deserves further investigation.

  2. New tyrosinase inhibitory decapeptide: Molecular insights into the role of tyrosine residues.

    Science.gov (United States)

    Ochiai, Akihito; Tanaka, Seiya; Imai, Yuta; Yoshida, Hisashi; Kanaoka, Takumi; Tanaka, Takaaki; Taniguchi, Masayuki

    2016-06-01

    Tyrosinase, a rate-limiting enzyme in melanin biosynthesis, catalyzes the hydroxylation of l-tyrosine to 3,4-dihydroxy-l-phenylalanine (l-dopa) (monophenolase reaction) and the subsequent oxidation of l-dopa to l-dopaquinone (diphenolase reaction). Thus, tyrosinase inhibitors have been proposed as skin-lightening agents; however, many of the existing inhibitors cannot be widely used in the cosmetic industry due to their high cytotoxicity and instability. On the other hand, some tyrosinase inhibitory peptides have been reported as safe. In this study, we found that the peptide TH10, which has a similar sequence to the characterized inhibitory peptide P4, strongly inhibits the monophenolase reaction with a half-maximal inhibitory concentration of 102 μM. Seven of the ten amino acid residues in TH10 were identical to P4; however, TH10 possesses one N-terminal tyrosine, whereas P4 contains three tyrosine residues located at its N-terminus, center, and C-terminus. Subsequent analysis using sequence-shuffled variants indicated that the tyrosine residues located at the N-terminus and center of P4 have little to no contribution to its inhibitory activity. Furthermore, docking simulation analysis of these peptides with mushroom tyrosinase demonstrated that the active tyrosine residue was positioned close to copper ions, suggesting that TH10 and P4 bind to tyrosinase as a substrate analogue. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  3. Preschool Inhibitory Control Predicts ADHD Group Status and Inhibitory Weakness in School.

    Science.gov (United States)

    Jacobson, Lisa A; Schneider, Heather; Mahone, E Mark

    2017-12-26

    Discriminative utility of performance measures of inhibitory control was examined in preschool children with and without ADHD to determine whether performance measures added to diagnostic prediction and to prediction of informant-rated day-to-day executive function. Children ages 4-5 years (N = 105, 61% boys; 54 ADHD, medication-naïve) were assessed using performance measures (Auditory Continuous Performance Test for Preschoolers-Commission errors, Conflicting Motor Response Test, NEPSY Statue) and caregiver (parent, teacher) ratings of inhibition (Behavior Rating Inventory of Executive Function-Preschool version). Performance measures and parent and teacher reports of inhibitory control significantly and uniquely predicted ADHD group status; however, performance measures did not add to prediction of group status beyond parent reports. Performance measures did significantly predict classroom inhibitory control (teacher ratings), over and above parent reports of inhibitory control. Performance measures of inhibitory control may be adequate predictors of ADHD status and good predictors of young children's classroom inhibitory control, demonstrating utility as components of clinical assessments. © The Author(s) 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. Emergent spatial patterns of excitatory and inhibitory synaptic strengths drive somatotopic representational discontinuities and their plasticity in a computational model of primary sensory cortical area 3b

    Directory of Open Access Journals (Sweden)

    Kamil A. Grajski

    2016-07-01

    Full Text Available Mechanisms underlying the emergence and plasticity of representational discontinuities in the mammalian primary somatosensory cortical representation of the hand are investigated in a computational model. The model consists of an input lattice organized as a three-digit hand forward-connected to a lattice of cortical columns each of which contains a paired excitatory and inhibitory cell. Excitatory and inhibitory synaptic plasticity of feedforward and lateral connection weights is implemented as a simple covariance rule and competitive normalization. Receptive field properties are computed independently for excitatory and inhibitory cells and compared within and across columns. Within digit representational zones intracolumnar excitatory and inhibitory receptive field extents are concentric, single-digit, small, and unimodal. Exclusively in representational boundary-adjacent zones, intracolumnar excitatory and inhibitory receptive field properties diverge: excitatory cell receptive fields are single-digit, small, and unimodal; and the paired inhibitory cell receptive fields are bimodal, double-digit, and large. In simulated syndactyly (webbed fingers, boundary-adjacent intracolumnar receptive field properties reorganize to within-representation type; divergent properties are reacquired following syndactyly release. This study generates testable hypotheses for assessment of cortical laminar-dependent receptive field properties and plasticity within and between cortical representational zones. For computational studies, present results suggest that concurrent excitatory and inhibitory plasticity may underlie novel emergent properties.

  5. Exploiting Inhibitory Siglecs to Combat Food Allergies

    Science.gov (United States)

    2017-10-01

    AWARD NUMBER: W81XWH-16-1-0302 TITLE: Exploiting Inhibitory Siglecs to Combat Food Allergies PRINCIPAL INVESTIGATOR: Michael Kulis, Ph.D...CONTRACTING ORGANIZATION: University of North Carolina at Chapel Hill Chapel Hill, NC 27599 REPORT DATES: October 2017 TYPE OF REPORT: Annual PREPARED FOR...Department of Defense, Washington Headquarters Services , Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite

  6. Inhibitory Interneurons, Oxidative Stress, and Schizophrenia

    OpenAIRE

    Sullivan, Elyse M.; O’Donnell, Patricio

    2012-01-01

    Translational studies are becoming more common in schizophrenia research. The past couple of decades witnessed the emergence of novel ideas regarding schizophrenia pathophysiology that originated from both human and animal studies. The findings that glutamate and gamma-aminobutyric acid transmission are affected in the disease led to the hypothesis of altered inhibitory neurotransmission as critical for cognitive deficits and to an exploration of novel therapeutic approaches aimed at restorin...

  7. New approaches to the synthesis of sildenafil analogues and their enzyme inhibitory activity

    Czech Academy of Sciences Publication Activity Database

    Mojzych, M.; Karczmarzyk, Z.; Wysocki, W.; Ceruso, M.; Supuran, C.T.; Kryštof, Vladimír; Urbanczyk-Lipkowska, Z.; Kalicki, P.

    2015-01-01

    Roč. 23, č. 7 (2015), s. 1421-1429 ISSN 0968-0896 R&D Projects: GA ČR GAP305/12/0783 Grant - others:GA MŠk(CZ) ED0007/01/01 Program:ED Institutional support: RVO:61389030 Keywords : Sildenafil analogues * Pyrazolo[4,3-e][1,2,4] triazine * Sulfonamides Subject RIV: CE - Biochemistry Impact factor: 2.923, year: 2015

  8. oxadiazole-5-thiol derivatives. 2. Anti-bacterial, enzyme- inhibitory an

    African Journals Online (AJOL)

    Methods: Antibacterial activities of the compounds were evaluated using broth dilution ... butyrylcholinesterase (BchE) and lipoxygenase (LOX) using acarbose, eserine and baicalien as .... ºC, absorbance was measured at 400 nm using.

  9. PSTPIP2, a Protein Associated with Autoinflammatory Disease, Interacts with Inhibitory Enzymes SHIP1 and Csk

    Czech Academy of Sciences Publication Activity Database

    Drobek, Aleš; Králová, Jarmila; Skopcová, Tereza; Kucová, Markéta; Novák, Petr; Angelisová, Pavla; Otáhal, Pavel; Alberich-Jorda, Meritxell; Brdička, Tomáš

    2015-01-01

    Roč. 195, č. 7 (2015), s. 3416-3426 ISSN 0022-1767 R&D Projects: GA ČR GAP302/12/1712; GA ČR GA15-03796S; GA MŠk LK21307; GA MŠk(CZ) EE2.3.30.0003; GA MŠk(CZ) ED1.1.00/02.0109; GA MŠk LO1509 Institutional support: RVO:61388971 ; RVO:68378050 Keywords : PSTPIP2 * autoinflammatory disorder * neutrophil Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.985, year: 2015

  10. An unusual helix-turn-helix protease inhibitory motif in a novel trypsin inhibitor from seeds of Veronica (Veronica hederifolia L.).

    Science.gov (United States)

    Conners, Rebecca; Konarev, Alexander V; Forsyth, Jane; Lovegrove, Alison; Marsh, Justin; Joseph-Horne, Timothy; Shewry, Peter; Brady, R Leo

    2007-09-21

    The storage tissues of many plants contain protease inhibitors that are believed to play an important role in defending the plant from invasion by pests and pathogens. These proteinaceous inhibitor molecules belong to a number of structurally distinct families. We describe here the isolation, purification, initial inhibitory properties, and three-dimensional structure of a novel trypsin inhibitor from seeds of Veronica hederifolia (VhTI). The VhTI peptide inhibits trypsin with a submicromolar apparent K(i) and is expected to be specific for trypsin-like serine proteases. VhTI differs dramatically in structure from all previously described families of trypsin inhibitors, consisting of a helix-turn-helix motif, with the two alpha helices tightly associated by two disulfide bonds. Unusually, the crystallized complex is in the form of a stabilized acyl-enzyme intermediate with the scissile bond of the VhTI inhibitor cleaved and the resulting N-terminal portion of the inhibitor remaining attached to the trypsin catalytic serine 195 by an ester bond. A synthetic, truncated version of the VhTI peptide has also been produced and co-crystallized with trypsin but, surprisingly, is seen to be uncleaved and consequently forms a noncovalent complex with trypsin. The VhTI peptide shows that effective enzyme inhibitors can be constructed from simple helical motifs and provides a new scaffold on which to base the design of novel serine protease inhibitors.

  11. Curcumin inhibits development and cell adhesion in Dictyostelium discoideum: Implications for YakA signaling and GST enzyme function

    Energy Technology Data Exchange (ETDEWEB)

    Garige, Mamatha; Walters, Eric, E-mail: ewalters@howard.edu

    2015-11-13

    The molecular basis for nutraceutical properties of the polyphenol curcumin (Curcuma longa, Turmeric) is complex, affecting multiple factors that regulate cell signaling and homeostasis. Here, we report the effect of curcumin on cellular and developmental mechanisms in the eukaryotic model, Dictyostelium discoideum. Dictyostelium proliferation was inhibited in the presence of curcumin, which also suppressed the prestarvation marker, discoidin I, members of the yakA-mediated developmental signaling pathway, and expression of the extracellular matrix/cell adhesion proteins (DdCAD and csA). This resulted in delayed chemotaxis, adhesion, and development of the organism. In contrast to the inhibitory effects on developmental genes, curcumin induced gstA gene expression, overall GST activity, and generated production of reactive oxygen species. These studies expand our knowledge of developmental and biochemical signaling influenced by curcumin, and lends greater consideration of GST enzyme function in eukaryotic cell signaling, development, and differentiation.

  12. Curcumin inhibits development and cell adhesion in Dictyostelium discoideum: Implications for YakA signaling and GST enzyme function

    International Nuclear Information System (INIS)

    Garige, Mamatha; Walters, Eric

    2015-01-01

    The molecular basis for nutraceutical properties of the polyphenol curcumin (Curcuma longa, Turmeric) is complex, affecting multiple factors that regulate cell signaling and homeostasis. Here, we report the effect of curcumin on cellular and developmental mechanisms in the eukaryotic model, Dictyostelium discoideum. Dictyostelium proliferation was inhibited in the presence of curcumin, which also suppressed the prestarvation marker, discoidin I, members of the yakA-mediated developmental signaling pathway, and expression of the extracellular matrix/cell adhesion proteins (DdCAD and csA). This resulted in delayed chemotaxis, adhesion, and development of the organism. In contrast to the inhibitory effects on developmental genes, curcumin induced gstA gene expression, overall GST activity, and generated production of reactive oxygen species. These studies expand our knowledge of developmental and biochemical signaling influenced by curcumin, and lends greater consideration of GST enzyme function in eukaryotic cell signaling, development, and differentiation.

  13. Inhibition of angiotensin-1-converting enzyme activity by two varieties of ginger (Zingiber officinale) in rats fed a high cholesterol diet.

    Science.gov (United States)

    Akinyemi, Ayodele Jacob; Ademiluyi, Adedayo Oluwaseun; Oboh, Ganiyu

    2014-03-01

    Angiotensin-1-converting enzyme (ACE) inhibitors are widely used in the treatment of cardiovascular diseases. This study sought to investigate the inhibitory effect of two varieties of ginger (Zingiber officinale) commonly consumed in Nigeria on ACE activity in rats fed a high cholesterol diet. The inhibition of ACE activity of two varieties of ginger (Z. officinale) was investigated in a high cholesterol (2%) diet fed to rats for 3 days. Feeding high cholesterol diets to rats caused a significant (Pginger varieties. Rats that were fed 4% white ginger had the greatest inhibitory effect as compared with a control diet. Furthermore, there was a significant (Pginger (either 2% or 4%) caused a significant (Pginger had the greatest reduction as compared with control diet. In conclusion, both ginger varieties exhibited anti-hypercholesterolemic properties in a high cholesterol diet fed to rats. This activity of the gingers may be attributed to its ACE inhibitory activity. However, white ginger inhibited ACE better in a high cholesterol diet fed to rats than red ginger. Therefore, both gingers could serve as good functional foods/nutraceuticals in the management/treatment of hypertension and other cardiovascular diseases.

  14. Secoiridoids from the stem barks of Fraxinus rhynchophylla with pancreatic lipase inhibitory activity.

    Science.gov (United States)

    Ahn, Jong Hoon; Shin, Eunjin; Liu, Qing; Kim, Seon Beom; Choi, Kyeong-Mi; Yoo, Hwan-Soo; Hwang, Bang Yeon; Lee, Mi Kyeong

    2013-01-01

    Pancreatic lipase digests dietary fats by hydrolysis, which is a key enzyme for lipid absorption. Therefore, reduction of fat absorption by the inhibition of pancreatic lipase is suggested to be a therapeutic strategy for obesity. From the EtOAc-soluble fraction of the stem barks of Fraxinus rhynchophylla (Oleaceae), four secoiridoids such as ligstroside (1), oleuropein (2), 2"-hydroxyoleuropein (3) and hydroxyframoside B (4) were isolated. The inhibitory activity of these compounds on pancreatic lipase was assessed using porcine pancreatic lipase as an in vitro assay system. Compound 4 showed the strongest inhibition on pancreatic lipase, which followed by compounds 1-3. In addition, compound 4 exerted inhibitory effect on pancreatic lipase in a mixed mechanism of competitive and noncompetitive manner. Taken together, F. rhynchophylla and its constituents might be beneficial to obesity.

  15. Mitochondrial reactive oxygen species regulate the strength of inhibitory GABA-mediated synaptic transmission

    Science.gov (United States)

    Accardi, Michael V.; Daniels, Bryan A.; Brown, Patricia M. G. E.; Fritschy, Jean-Marc; Tyagarajan, Shiva K.; Bowie, Derek

    2014-01-01

    Neuronal communication imposes a heavy metabolic burden in maintaining ionic gradients essential for action potential firing and synaptic signalling. Although cellular metabolism is known to regulate excitatory neurotransmission, it is still unclear whether the brain’s energy supply affects inhibitory signalling. Here we show that mitochondrial-derived reactive oxygen species (mROS) regulate the strength of postsynaptic GABAA receptors at inhibitory synapses of cerebellar stellate cells. Inhibition is strengthened through a mechanism that selectively recruits α3-containing GABAA receptors into synapses with no discernible effect on resident α1-containing receptors. Since mROS promotes the emergence of postsynaptic events with unique kinetic properties, we conclude that newly recruited α3-containing GABAA receptors are activated by neurotransmitter released onto discrete postsynaptic sites. Although traditionally associated with oxidative stress in neurodegenerative disease, our data identify mROS as a putative homeostatic signalling molecule coupling cellular metabolism to the strength of inhibitory transmission.

  16. Archaeal Enzymes and Applications in Industrial Biocatalysts.

    Science.gov (United States)

    Littlechild, Jennifer A

    2015-01-01

    Archaeal enzymes are playing an important role in industrial biotechnology. Many representatives of organisms living in "extreme" conditions, the so-called Extremophiles, belong to the archaeal kingdom of life. This paper will review studies carried by the Exeter group and others regarding archaeal enzymes that have important applications in commercial biocatalysis. Some of these biocatalysts are already being used in large scale industrial processes for the production of optically pure drug intermediates and amino acids and their analogues. Other enzymes have been characterised at laboratory scale regarding their substrate specificity and properties for potential industrial application. The increasing availability of DNA sequences from new archaeal species and metagenomes will provide a continuing resource to identify new enzymes of commercial interest using both bioinformatics and screening approaches.

  17. Enzymic lactose hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J J; Brand, J C

    1980-01-01

    Acid or enzymic hydrolysis can be used to hydrolyze lactose. Advantages of both are compared and details of enzymic hydrolysis using yeast or fungal enzymes given. The new scheme outlined involves recycling lactase. Because lactose and lactase react to ultrafiltration (UF) membranes differently separation is possible. Milk or milk products are ultrafiltered to separate a concentrate from a lactose-rich permeate which is treated with lactase in a reactor until hydrolysis reaches a required level. The lactase can be removed by UF as it does not permeate the membrane, and it is recycled back to the reactor. Permeate from the second UF stage may or may not be recombined with the concentrate from the first stage to produce a low lactose product (analysis of a typical low-lactose dried whole milk is given). Batch or continuous processes are explained and a batch process without enzyme recovery is discussed. (Refs. 4).

  18. Indicators: Sediment Enzymes

    Science.gov (United States)

    Sediment enzymes are proteins that are produced by microorganisms living in the sediment or soil. They are indicators of key ecosystem processes and can help determine which nutrients are affecting the biological community of a waterbody.

  19. Enzyme Vs. Extremozyme -32 ...

    Indian Academy of Sciences (India)

    Enzymes are biocatalytic protein molecules that enhance the rates of ... to physical forces (hydrogen bonds, hydrophobic 1, electrostatic and Van der ... conformation. In 1995 ... surface against 14.7% in Klenow poll (some of the hydrophobic.

  20. Overproduction of ligninolytic enzymes

    Science.gov (United States)

    Elisashvili, Vladimir; Kachlishvili, Eva; Torok, Tamas

    2014-06-17

    Methods, compositions, and systems for overproducing ligninolytic enzymes from the basidiomycetous fungus are described herein. As described, the method can include incubating a fungal strain of Cerrena unicolor IBB 303 in a fermentation system having growth medium which includes lignocellulosic material and then cultivating the fungal strain in the fermentation system under conditions wherein the fungus expresses the ligninolytic enzymes. In some cases, the lignocellulosic material is mandarin peel, ethanol production residue, walnut pericarp, wheat bran, wheat straw, or banana peel.

  1. Inhibition and kinetic studies of lignin degrading enzymes of Ganoderma boninense by naturally occurring phenolic compounds.

    Science.gov (United States)

    Surendran, Arthy; Siddiqui, Yasmeen; Saud, Halimi Mohd; Ali, Nusaibah Syd; Manickam, Sivakumar

    2018-05-22

    Lignolytic (Lignin degrading) enzyme, from oil palm pathogen Ganoderma boninense Pat. (Syn G. orbiforme (Ryvarden), is involved in the detoxification and the degradation of lignin in the oil palm and is the rate-limiting step in the infection process of this fungus. Active inhibition of lignin degrading enzymes secreted by G. boninense by various naturally occurring phenolic compounds and estimation of efficiency on pathogen suppression was aimed at. In our work, ten naturally occurring phenolic compounds were evaluated for their inhibitory potential towards the lignolytic enzymes of G.boninense. Additionally, the lignin degrading enzymes were characterised. Most of the peholic compounds exhibited an uncompetitive inhibition towards the lignin degrading enzymes. Benzoic acid was the superior inhibitor to the production of lignin degrading enzymes, when compared between the ten phenolic compounds. The inhibitory potential of the phenolic compounds toward the lignin degrading enzymes are higher than that of the conventional metal ion inhibitor. The lignin degrading enzymes were stable in a wide range of pH but were sensitive to higher to temperature. The study demonstrated the inhibitor potential of ten naturally occurring phenolic compounds toward the lignin degrading enzymes of G. boninense with different efficacies. The study has shed a light towards a new management strategy to control BSR in oil palm. It serves as replacement for the existing chemical control. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  2. Measurement of enzyme activity.

    Science.gov (United States)

    Harris, T K; Keshwani, M M

    2009-01-01

    To study and understand the nature of living cells, scientists have continually employed traditional biochemical techniques aimed to fractionate and characterize a designated network of macromolecular components required to carry out a particular cellular function. At the most rudimentary level, cellular functions ultimately entail rapid chemical transformations that otherwise would not occur in the physiological environment of the cell. The term enzyme is used to singularly designate a macromolecular gene product that specifically and greatly enhances the rate of a chemical transformation. Purification and characterization of individual and collective groups of enzymes has been and will remain essential toward advancement of the molecular biological sciences; and developing and utilizing enzyme reaction assays is central to this mission. First, basic kinetic principles are described for understanding chemical reaction rates and the catalytic effects of enzymes on such rates. Then, a number of methods are described for measuring enzyme-catalyzed reaction rates, which mainly differ with regard to techniques used to detect and quantify concentration changes of given reactants or products. Finally, short commentary is given toward formulation of reaction mixtures used to measure enzyme activity. Whereas a comprehensive treatment of enzymatic reaction assays is not within the scope of this chapter, the very core principles that are presented should enable new researchers to better understand the logic and utility of any given enzymatic assay that becomes of interest.

  3. Synthesis of chiral pyrazolo[4,3-e][1,2,4]triazine sulfonamides with tyrosinase and urease inhibitory activity.

    Science.gov (United States)

    Mojzych, Mariusz; Tarasiuk, Paweł; Kotwica-Mojzych, Katarzyna; Rafiq, Muhammad; Seo, Sung-Yum; Nicewicz, Michał; Fornal, Emilia

    2017-12-01

    A new series of sulfonamide derivatives of pyrazolo[4,3-e][1,2,4]triazine with chiral amino group has been synthesized and characterized. The compounds were tested for their tyrosinase and urease inhibitory activity. Evaluation of prepared derivatives demonstrated that compounds (8b) and (8j) are most potent mushroom tyrosinase inhibitors whereas all of the obtained compounds showed higher urease inhibitory activity than the standard thiourea. The compounds (8a), (8f) and (8i) exhibited excellent enzyme inhibitory activity with IC 50 0.037, 0.044 and 0.042 μM, respectively, while IC 50 of thiourea is 20.9 μM.

  4. Polyphenols of Salix aegyptiaca modulate the activities of drug metabolizing and antioxidant enzymes, and level of lipid peroxidation.

    Science.gov (United States)

    Nauman, Mohd; Kale, R K; Singh, Rana P

    2018-03-07

    Salix aegyptiaca is known for its medicinal properties mainly due to the presence of salicylate compounds. However, it also contains other beneficial phytochemicals such as gallic acid, quercetin, rutin and vanillin. The aim of the study was to examine the redox potential, antioxidant and anti-inflammatory activity of these phytochemicals along with acetylsalicylic acid. The redox potential and antioxidant activity of gallic acid, quercetin, rutin, vanillin and acetylsalicylic acid were determined by oxidation-reduction potential electrode method and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, respectively. In ex vivo studies, antioxidant activity of these phytochemicals was determined by lipid peroxidation and carbonyl content assay in the liver of mice. Anti-inflammatory activity was determined by protein denaturation method. Six-week old C57BL/6 mice treated with gallic acid (100 mg/kg body weight) and acetylsalicylic acid (25 and 50 mg/kg body weight) to investigate their in vivo modulatory effects on the specific activities of drug metabolizing phase I and phase II enzymes, antioxidant enzymes and level of lipid peroxidation in liver. The order of ability to donate electron and antioxidant activity was found to be: gallic acid > quercetin > rutin > vanillin > acetylsalicylic acid. In ex vivo studies, the similar pattern and magnitude of inhibitory effects of these phytochemicals against peroxidative damage in microsomes and protein carbonyl in cytosolic fraction were observed. In in vivo studies, gallic acid and acetylsalicylic acid alone or in combination, enhanced the specific activities of drug metabolizing phase I and phase II enzymes as well as antioxidant enzymes and also inhibited lipid peroxidation in liver. These findings show a close link between the electron donation and antioxidation potential of these phytochemicals, and in turn their biological activity. Gallic acid, quercetin, rutin and vanillin were found to be better electron donors and

  5. A PM7 dynamic residue-ligand interactions energy landscape of the BACE1 inhibitory pathway by hydroxyethylamine compounds. Part I: The flap closure process.

    Science.gov (United States)

    Gueto-Tettay, Carlos; Martinez-Consuegra, Alejandro; Zuchniarz, Joshua; Gueto-Tettay, Luis Roberto; Drosos-Ramírez, Juan Carlos

    2017-09-01

    BACE1 is an enzyme of scientific interest because it participates in the progression of Alzheimer's disease. Hydroxyethylamines (HEAs) are a family of compounds which exhibit inhibitory activity toward BACE1 at a nanomolar level, favorable pharmacokinetic properties and oral bioavailability. The first step in the inhibition of BACE1 by HEAs consists of their entrance into the protease active site and the resultant conformational change in the protein, from Apo to closed form. These two conformations differ in the position of an antiparallel loop (called the flap) which covers the entrance to the catalytic site. For BACE1, closure of this flap is vital to its catalytic activity and to inhibition of the enzyme due to the new interactions thereby formed with the ligand. In the present study a dynamic energy landscape of residue-ligand interaction energies (ReLIE) measured for 112 amino acids in the BACE1 active site and its immediate vicinity during the closure of the flap induced by 8 HEAs of different inhibitory power is presented. A total of 6.272 million ReLIE calculations, based on the PM7 semiempirical method, provided a deep and quantitative view of the first step in the inhibition of the aspartyl protease. The information suggests that residues Asp93, Asp289, Thr292, Thr293, Asn294 and Arg296 are anchor points for the ligand, accounting for approximately 45% of the total protein-ligand interaction. Additionally, flap closure improved the BACE1-HEA interaction by around 25%. Furthermore, the inhibitory activity of HEAs could be related to the capacity of these ligands to form said anchor point interactions and maintain them over time: the lack of some of these anchor interactions delayed flap closure or impeded it completely, or even caused the flap to reopen. The methodology employed here could be used as a tool to evaluate future structural modifications which lead to improvements in the favorability and stability of BACE1-HEA ReLIEs, aiding in the design of

  6. Acetylcholinesterase inhibitory effects of some plants from Rosaceae

    Directory of Open Access Journals (Sweden)

    S. Esmaeili

    2015-10-01

    Full Text Available Background and objectives: Alzheimer's disease (AD is an age dependent disorder. AD is associated with decrease of brain acetylcholine level. Nowadays, one of the methods for progression inhibition of AD is using acetylcholinesterase inhibitors. Rosaceae is a large plant family. Different biological effects of some species of this family have been reported. The aim of the present study was to assess the acetylcholinesterase inhibitory (AChEI activity of the selected plants belonging to Rosaceae family. Methods: AChEI activity of six species from Rosaceae including Cotoneaster nummularia, Cerasus microcarpa, Amygdalus scoparia, Agrimonia eupatoria, Rosa canina and Rosa damascena were evaluated based on Ellman’s method in concentration of 300 µg/mL using total extracts and methanol fractions which were obtained by maceration. Results: The results showed that the total extract and methanol fraction of the aerial parts of A. eupatoria demonstrated significant AChEI activity with 46.5% and 56.2% inhibition of the enzyme, respectively. Conclusion: According to the results of the AChEI activity of the methanol fraction of A. eupatoria, it seems that the polar components of the species such as flavonoids may be responsible for its effectiveness.

  7. Purification, characterization of phytase enzyme from Lactobacillus ...

    African Journals Online (AJOL)

    Purification, characterization of phytase enzyme from Lactobacillus plantarum bacteria and determination of its kinetic properties. ... Many of the cereal grains, legumes and oilseeds store phosphorus in phytate form. Phytases can be produced by plants, animals and microorganisms. However, the ones with microbial origin ...

  8. Mutation in rod PDE6 linked to congenital stationary night blindness impairs the enzyme inhibition by its gamma-subunit.

    Science.gov (United States)

    Muradov, Khakim G; Granovsky, Alexey E; Artemyev, Nikolai O

    2003-03-25

    Photoreceptor cGMP phosphodiesterase (PDE6) is the effector enzyme in the vertebrate visual transduction cascade. The activity of rod PDE6 catalytic alpha- and beta-subunits is blocked in the dark by two inhibitory Pgamma-subunits. The inhibition is released upon light-stimulation of photoreceptor cells. Mutation H258N in PDE6beta has been linked to congenital stationary night blindness (CSNB) in a large Danish family (Rambusch pedigree) (Gal, A., Orth, U., Baehr, W., Schwinger, E., and Rosenberg, T. (1994) Nat. Genet. 7, 64-67.) We have analyzed the consequences of this mutation for PDE6 function using a Pgamma-sensitive PDE6alpha'/PDE5 chimera, Chi16. Biochemical analysis of the H257N mutant, an equivalent of PDE6betaH258N, demonstrates that this substitution does not alter the ability of chimeric PDE to dimerize or the enzyme's catalytic properties. The sensitivity of H257N to a competitive inhibitor zaprinast was also unaffected. However, the mutant displayed a significant impairment in the inhibitory interaction with Pgamma, which was apparent from a approximately 20-fold increase in the K(i) value (46 nM) and incomplete maximal inhibition. The inhibitory defect of H257N is not due to perturbation of noncatalytic cGMP binding to the PDE6alpha' GAF domains. The noncatalytic cGMP-binding characteristics of the H257N mutant were similar to those of the parent PDE6alpha'/PDE5 chimera. Since rod PDE6 in the Rambusch CSNB is a catalytic heterodimer of the wild-type PDE6alpha and mutant PDE6beta, Chi16 and H257N were coexpressed, and a heterodimeric PDE, Chi16/H257N, was isolated. It displayed two Pgamma inhibitory sites with the K(i) values of 5 and 57 nM. Our results support the hypothesis that mutation H258N in PDE6beta causes CSNB through incomplete inhibition of PDE6 activity by Pgamma, which leads to desensitization of rod photoreceptors.

  9. Ophiamides A-B, new potent urease inhibitory sphingolipids from Heliotropium ophioglossum.

    Science.gov (United States)

    Firdous, Sadiqa; Ansari, Nida Hassan; Fatima, Itrat; Malik, Abdul; Afza, Nighat; Iqbal, Lubna; Lateef, Mehreen

    2012-07-01

    Ophiamides A (1) and B (2), two new sphingolipids have been isolated from the n-hexane subfraction of the MeOH extract of the whole plant of Heliotropium ophioglossum along with glycerol monopalmitate (3) and β-sitosterol 3-O-β-D: -glucoside (4) reported for the first time from this species. Their structures were elucidated by spectroscopic techniques including MS and 2D-NMR spectroscopy. Both the compounds 1 and 2 showed potent inhibitory activity against the enzyme urease.

  10. Inhibitory neurotransmission and olfactory memory in honeybees.

    Science.gov (United States)

    El Hassani, Abdessalam Kacimi; Giurfa, Martin; Gauthier, Monique; Armengaud, Catherine

    2008-11-01

    In insects, gamma-aminobutyric acid (GABA) and glutamate mediate fast inhibitory neurotransmission through ligand-gated chloride channel receptors. Both GABA and glutamate have been identified in the olfactory circuit of the honeybee. Here we investigated the role of inhibitory transmission mediated by GABA and glutamate-gated chloride channels (GluCls) in olfactory learning and memory in honeybees. We combined olfactory conditioning with injection of ivermectin, an agonist of GluCl receptors. We also injected a blocker of glutamate transporters (L-trans-PDC) or a GABA analog (TACA). We measured acquisition and retention 1, 24 and 48 h after the last acquisition trial. A low dose of ivermectin (0.01 ng/bee) impaired long-term olfactory memory (48 h) while a higher dose (0.05 ng/bee) had no effect. Double injections of ivermectin and L-trans-PDC or TACA had different effects on memory retention, depending on the doses and agents combined. When the low dose of ivermectin was injected after Ringer, long-term memory was again impaired (48 h). Such an effect was rescued by injection of both TACA and L-trans-PDC. A combination of the higher dose of ivermectin and TACA decreased retention at 48 h. We interpret these results as reflecting the involvement of both GluCl and GABA receptors in the impairment of olfactory long-term memory induced by ivermectin. These results illustrate the diversity of inhibitory transmission and its implication in long-term olfactory memory in honeybees.

  11. Interaction between Red Yeast Rice and CYP450 Enzymes/P-Glycoprotein and Its Implication for the Clinical Pharmacokinetics of Lovastatin

    Directory of Open Access Journals (Sweden)

    Chia-Hao Chen

    2012-01-01

    Full Text Available Red yeast rice (RYR can reduce cholesterol through its active component, lovastatin. This study was to investigate the pharmacokinetic properties of lovastatin in RYR products and potential RYR-drug interactions. Extracts of three registered RYR products (LipoCol Forte, Cholestin, and Xuezhikang were more effective than pure lovastatin in inhibiting the activities of cytochrome P450 enzymes and P-glycoprotein. Among CYP450 enzymes, RYR showed the highest inhibition on CYP1A2 and CYP2C19, with comparable inhibitory potencies to the corresponding typical inhibitors. In healthy volunteers taking the RYR product LipoCol Forte, the pharmacokinetic properties of lovastatin and lovastatin acid were linear in the dose range of 1 to 4 capsules taken as a single dose and no significant accumulation was observed after multiple dosing. Concomitant use of one LipoCol Forte capsule with nifedipine did not change the pharmacokinetics of nifedipine. Yet, concomitant use of gemfibrozil with LipoCol Forte resulted in a significant increase in the plasma concentration of lovastatin acid. These findings suggest that the use of RYR products may not have effects on the pharmacokinetics of concomitant comedications despite their effects to inhibit the activities of CYP450 enzymes and P-gp, whereas gemfibrozil affects the pharmacokinetics of lovastatin acid when used concomitantly with RYR products.

  12. Chemical Composition and Cholinesterase Inhibitory Activity of Different Parts of Daucus aristidis Coss. Essential Oils from Two Locations in Algeria

    OpenAIRE

    Mebarka Lamamra; Hocine Laouer; Smain Amira; Ilkay Erdogan Orhan; Fatma Sezer Senol; Betul Demirci; Salah Akkal

    2017-01-01

    The chemical composition of the essential oils obtained by hydrodistillation from the different parts of Daucus aristidis Coss. (syn. Ammiopsis aristidis Batt.) (Apiaceae) from two locations (Ghoufi and Bousaada) in East of Algeria, was investigated for the first time by GC and GC-MS and evaluated for their in vitro acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity, the enzymes linked to Alzheimer’s disease, by a spectrophotometric method of Ellman using ELISA m...

  13. Random-walk enzymes

    Science.gov (United States)

    Mak, Chi H.; Pham, Phuong; Afif, Samir A.; Goodman, Myron F.

    2015-09-01

    Enzymes that rely on random walk to search for substrate targets in a heterogeneously dispersed medium can leave behind complex spatial profiles of their catalyzed conversions. The catalytic signatures of these random-walk enzymes are the result of two coupled stochastic processes: scanning and catalysis. Here we develop analytical models to understand the conversion profiles produced by these enzymes, comparing an intrusive model, in which scanning and catalysis are tightly coupled, against a loosely coupled passive model. Diagrammatic theory and path-integral solutions of these models revealed clearly distinct predictions. Comparison to experimental data from catalyzed deaminations deposited on single-stranded DNA by the enzyme activation-induced deoxycytidine deaminase (AID) demonstrates that catalysis and diffusion are strongly intertwined, where the chemical conversions give rise to new stochastic trajectories that were absent if the substrate DNA was homogeneous. The C →U deamination profiles in both analytical predictions and experiments exhibit a strong contextual dependence, where the conversion rate of each target site is strongly contingent on the identities of other surrounding targets, with the intrusive model showing an excellent fit to the data. These methods can be applied to deduce sequence-dependent catalytic signatures of other DNA modification enzymes, with potential applications to cancer, gene regulation, and epigenetics.

  14. Impact of Bee Venom Enzymes on Diseases and Immune Responses.

    Science.gov (United States)

    Hossen, Md Sakib; Shapla, Ummay Mahfuza; Gan, Siew Hua; Khalil, Md Ibrahim

    2016-12-27

    Bee venom (BV) is used to treat many diseases and exhibits anti-inflammatory, anti-bacterial, antimutagenic, radioprotective, anti-nociceptive immunity promoting, hepatocyte protective and anti-cancer activity. According to the literature, BV contains several enzymes, including phospholipase A2 (PLA2), phospholipase B, hyaluronidase, acid phosphatase and α-glucosidase. Recent studies have also reported the detection of different classes of enzymes in BV, including esterases, proteases and peptidases, protease inhibitors and other important enzymes involved in carbohydrate metabolism. Nevertheless, the physiochemical properties and functions of each enzyme class and their mechanisms remain unclear. Various pharmacotherapeutic effects of some of the BV enzymes have been reported in several studies. At present, ongoing research aims to characterize each enzyme and elucidate their specific biological roles. This review gathers all the current knowledge on BV enzymes and their specific mechanisms in regulating various immune responses and physiological changes to provide a basis for future therapies for various diseases.

  15. Impact of Bee Venom Enzymes on Diseases and Immune Responses

    Directory of Open Access Journals (Sweden)

    Md. Sakib Hossen

    2016-12-01

    Full Text Available Bee venom (BV is used to treat many diseases and exhibits anti-inflammatory, anti-bacterial, antimutagenic, radioprotective, anti-nociceptive immunity promoting, hepatocyte protective and anti-cancer activity. According to the literature, BV contains several enzymes, including phospholipase A2 (PLA2, phospholipase B, hyaluronidase, acid phosphatase and α-glucosidase. Recent studies have also reported the detection of different classes of enzymes in BV, including esterases, proteases and peptidases, protease inhibitors and other important enzymes involved in carbohydrate metabolism. Nevertheless, the physiochemical properties and functions of each enzyme class and their mechanisms remain unclear. Various pharmacotherapeutic effects of some of the BV enzymes have been reported in several studies. At present, ongoing research aims to characterize each enzyme and elucidate their specific biological roles. This review gathers all the current knowledge on BV enzymes and their specific mechanisms in regulating various immune responses and physiological changes to provide a basis for future therapies for various diseases.

  16. α-Glucosidase and pancreatic lipase inhibitory activities and glucose uptake stimulatory effect of phenolic compounds from Dendrobium formosum

    Directory of Open Access Journals (Sweden)

    Prachyaporn Inthongkaew

    Full Text Available ABSTRACT A methanol extract from the whole plant of Dendrobium formosum Roxb. ex Lindl., Orchidaceae, showed inhibitory potential against α-glucosidase and pancreatic lipase enzymes. Chromatographic separation of the extract resulted in the isolation of twelve phenolic compounds. The structures of these compounds were determined through analysis of NMR and HR-ESI-MS data. All of the isolates were evaluated for their α-glucosidase and pancreatic lipase inhibitory activities, as well as glucose uptake stimulatory effect. Among the isolates, 5-methoxy-7-hydroxy-9,10-dihydro-1,4-phenanthrenequinone (12 showed the highest α-glucosidase and pancreatic lipase inhibitory effects with an IC50 values of 126.88 ± 0.66 µM and 69.45 ± 10.14 µM, respectively. An enzyme kinetics study was conducted by the Lineweaver-Burk plot method. The kinetics studies revealed that compound 12 was a non-competitive inhibitor of α-glucosidase and pancreatic lipase enzymes. Moreover, lusianthridin at 1 and 10 µg/ml and moscatilin at 100 µg/ml showed glucose uptake stimulatory effect without toxicity on L6 myotubes. This study is the first report on the phytochemical constituents and anti-diabetic and anti-obesity activities of D. formosum.

  17. Empirical and bioinformatic characterization of buffalo (Bubalus bubalis) colostrum whey peptides & their angiotensin I-converting enzyme inhibition.

    Science.gov (United States)

    Ashok, N R; Aparna, H S

    2017-08-01

    Whey based peptides are well known for their nutritional and multifunctional properties. In this context, whey proteins from buffalo colostrum & milk were digested by in vitro simulation digestion and analyzed by nano-LC-MS/MS. Functional protein association networks, gene annotations and localization of identified proteins were carried out. An ACE inhibitory peptide sorted from the library was custom synthesized and an in vitro ACE assay was performed. The study led to the identification of 74 small peptides which were clustered into 5 gene functional groups and majority of them were secretory proteins. Among the identified peptides, majority of them were found identical to angiotensin I-converting enzyme (ACE) inhibitors, antioxidant, antimicrobial, immunomodulatory and opioidal peptides. An octapeptide (m/z - 902.51, IQKVAGTW) synthesized was found to inhibit ACE with an IC 50 of 300±2µM. The present investigation thus establishes newer vista for food derived peptides having ACE inhibitory potential for nutraceutical or therapeutic applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Relationships between the structure of wheat gluten and ACE inhibitory activity of hydrolysate: stepwise multiple linear regression analysis.

    Science.gov (United States)

    Zhang, Yanyan; Ma, Haile; Wang, Bei; Qu, Wenjuan; Wali, Asif; Zhou, Cunshan

    2016-08-01

    Ultrasound pretreatment of wheat gluten (WG) before enzymolysis can improve the angiotensin converting enzyme (ACE) inhibitory activity of the hydrolysates by alerting the structure of substrate proteins. Establishment of a relationship between the structure of WG and ACE inhibitory activity of the hydrolysates to judge the end point of the ultrasonic pretreatment is vital. The results of stepwise multiple linear regression (MLR) showed that the contents of free sulfhydryl, α-helix, disulfide bond, surface hydrophobicity and random coil were significantly correlated to ACE Inhibitory activity of the hydrolysate, with the standard partial regression coefficients were 3.729, -0.676, -0.252, 0.022 and 0.156, respectively. The R(2) of this model was 0.970. External validation showed that the stepwise MLR model could well predict the ACE inhibitory activity of hydrolysate based on the content of free sulfhydryl, α-helix, disulfide bond, surface hydrophobicity and random coil of WG before hydrolysis. A stepwise multiple linear regression model describing the quantitative relationships between the structure of WG and the ACE Inhibitory activity of the hydrolysates was established. This model can be used to predict the endpoint of the ultrasonic pretreatment. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  19. Monoamine oxidase inhibitory activity in tobacco particulate matter: Are harman and norharman the only physiologically relevant inhibitors?

    Science.gov (United States)

    Truman, Penelope; Grounds, Peter; Brennan, Katharine A

    2017-03-01

    Monoamine oxidase inhibition is significant in smokers, but it is still unclear how the inhibition that is seen in the brains and bodies of smokers is brought about. Our aim was to test the contribution of the harman and norharman in tobacco smoke to MAO-A inhibition from tobacco smoke preparations, as part of a re-examination of harman and norharman as the cause of the inhibition of MAO-A inhibition in the brain. Tobacco smoke particulate matter and cigarette smoke particulate matter were prepared and the amounts of harman and norharman measured. The results were compared with the total monoamine oxidase-A inhibitory activity. At a nicotine concentration of 0.6μM (a "physiological" concentration in blood) the total monoamine oxidase-A inhibitory activity measured in these samples was sufficient to inhibit the enzyme by approximately 10%. Of this inhibitory activity, only a small proportion of the total was found to be due to harman and norharman. These results show that harman and norharman provide only a moderate contribution to the total monoamine oxidase-A inhibitory activity of tobacco smoke, perhaps under 10%. This suggests that other inhibitors (either known or unknown) may be more significant contributors to total inhibitory activity than has yet been established, and deserve closer examination. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Directed evolution of enzymes using microfluidic chips

    Science.gov (United States)

    Pilát, Zdeněk.; Ježek, Jan; Šmatlo, Filip; Kaůka, Jan; Zemánek, Pavel

    2016-12-01

    Enzymes are highly versatile and ubiquitous biological catalysts. They can greatly accelerate large variety of reactions, while ensuring appropriate catalytic activity and high selectivity. These properties make enzymes attractive biocatalysts for a wide range of industrial and biomedical applications. Over the last two decades, directed evolution of enzymes has transformed the field of protein engineering. We have devised microfluidic systems for directed evolution of haloalkane dehalogenases in emulsion droplets. In such a device, individual bacterial cells producing mutated variants of the same enzyme are encapsulated in microdroplets and supplied with a substrate. The conversion of a substrate by the enzyme produced by a single bacterium changes the pH in the droplet which is signalized by pH dependent fluorescence probe. The droplets with the highest enzymatic activity can be separated directly on the chip by dielectrophoresis and the resultant cell lineage can be used for enzyme production or for further rounds of directed evolution. This platform is applicable for fast screening of large libraries in directed evolution experiments requiring mutagenesis at multiple sites of a protein structure.

  1. Enzymes for Enhanced Oil Recovery (EOR)

    Energy Technology Data Exchange (ETDEWEB)

    Nasiri, Hamidreza

    2011-04-15

    Primary oil recovery by reservoir pressure depletion and secondary oil recovery by waterflooding usually result in poor displacement efficiency. As a consequence there is always some trapped oil remaining in oil reservoirs. Oil entrapment is a result of complex interactions between viscous, gravity and capillary forces. Improving recovery from hydrocarbon fields typically involves altering the relative importance of the viscous and capillary forces. The potential of many EOR methods depends on their influence on fluid/rock interactions related to wettability and fluid/fluid interactions reflected in IFT. If the method has the potential to change the interactions favorably, it may be considered for further investigation, i.e. core flooding experiment, pilot and reservoir implementation. Enzyme-proteins can be introduced as an enhanced oil recovery method to improve waterflood performance by affecting interactions at the oil-water-rock interfaces. An important part of this thesis was to investigate how selected enzymes may influence wettability and capillary forces in a crude oil-brine-rock system, and thus possibly contribute to enhanced oil recovery. To investigate further by which mechanisms selected enzyme-proteins may contribute to enhance oil recovery, groups of enzymes with different properties and catalytic functions, known to be interfacially active, were chosen to cover a wide range of possible effects. These groups include (1) Greenzyme (GZ) which is a commercial EOR enzyme and consists of enzymes and stabilizers (surfactants), (2) The Zonase group consists of two types of pure enzyme, Zonase1 and Zonase2 which are protease enzymes and whose catalytic functions are to hydrolyze (breakdown) peptide bonds, (3) The Novozyme (NZ) group consists of three types of pure enzyme, NZ2, NZ3 and NZ6 which are esterase enzymes and whose catalytic functions are to hydrolyze ester bonds, and (4) Alpha-Lactalbumin ( -La) which is an important whey protein. The effect of

  2. Functional delineation of three groups of the ATP-dependent family of chromatin remodeling enzymes.

    NARCIS (Netherlands)

    Boyer, L.A.; Logie, C.; Bonte, E; Becker, P.B.; Wade, P.A.; Wolff, A.P.; Wu, C.; Imbalzano, A.N.; Peterson, C.L.

    2000-01-01

    ATP-dependent chromatin remodeling enzymes antagonize the inhibitory effects of chromatin. We compare six different remodeling complexes: ySWI/SNF, yRSC, hSWI/SNF, xMi-2, dCHRAC, and dNURF. We find that each complex uses similar amounts of ATP to remodel nucleosomal arrays at nearly identical rates.

  3. Descriptive and predictive assessment of enzyme activity and enzyme related processes in biorefinery using IR spectroscopy and chemometrics

    DEFF Research Database (Denmark)

    Baum, Andreas

    the understanding of the structural properties of the extracted pectin. Secondly, enzyme kinetics of biomass converting enzymes was examined in terms of measuring enzyme activity by spectral evolution profiling utilizing FTIR. Chemometric multiway methods were used to analyze the tensor datasets enabling the second......-order calibration advantage (reference Theory of Analytical chemistry). As PAPER 3 illustrates the method is universally applicable without the need of any external standards and was exemplified by performing quantitative enzyme activity determinations for glucose oxidase, pectin lyase and a cellolytic enzyme blend...... (Celluclast 1.5L). In PAPER 4, the concept is extended to quantify enzyme activity of two simultaneously acting enzymes, namely pectin lyase and pectin methyl esterase. By doing so the multiway methods PARAFAC, TUCKER3 and NPLS were compared and evaluated towards accuracy and precision....

  4. Aldose reductase inhibitory compounds from Xanthium strumarium.

    Science.gov (United States)

    Yoon, Ha Na; Lee, Min Young; Kim, Jin-Kyu; Suh, Hong-Won; Lim, Soon Sung

    2013-09-01

    As part of our ongoing search for natural sources of therapeutic and preventive agents for diabetic complications, we evaluated the inhibitory effects of components of the fruit of Xanthium strumarium (X. strumarium) on aldose reductase (AR) and galactitol formation in rat lenses with high levels of glucose. To identify the bioactive components of X. strumarium, 7 caffeoylquinic acids and 3 phenolic compounds were isolated and their chemical structures were elucidated on the basis of spectroscopic evidence and comparison with published data. The abilities of 10 X. strumarium-derived components to counteract diabetic complications were investigated by means of inhibitory assays with rat lens AR (rAR) and recombinant human AR (rhAR). From the 10 isolated compounds, methyl-3,5-di-O-caffeoylquinate showed the most potent inhibition, with IC₅₀ values of 0.30 and 0.67 μM for rAR and rhAR, respectively. In the kinetic analyses using Lineweaver-Burk plots of 1/velocity and 1/substrate, methyl-3,5-di-O-caffeoylquinate showed competitive inhibition of rhAR. Furthermore, methyl-3,5-di-O-caffeoylquinate inhibited galactitol formation in the rat lens and in erythrocytes incubated with a high concentration of glucose, indicating that this compound may be effective in preventing diabetic complications.

  5. Rational decision-making in inhibitory control.

    Science.gov (United States)

    Shenoy, Pradeep; Yu, Angela J

    2011-01-01

    An important aspect of cognitive flexibility is inhibitory control, the ability to dynamically modify or cancel planned actions in response to changes in the sensory environment or task demands. We formulate a probabilistic, rational decision-making framework for inhibitory control in the stop signal paradigm. Our model posits that subjects maintain a Bayes-optimal, continually updated representation of sensory inputs, and repeatedly assess the relative value of stopping and going on a fine temporal scale, in order to make an optimal decision on when and whether to go on each trial. We further posit that they implement this continual evaluation with respect to a global objective function capturing the various reward and penalties associated with different behavioral outcomes, such as speed and accuracy, or the relative costs of stop errors and go errors. We demonstrate that our rational decision-making model naturally gives rise to basic behavioral characteristics consistently observed for this paradigm, as well as more subtle effects due to contextual factors such as reward contingencies or motivational factors. Furthermore, we show that the classical race model can be seen as a computationally simpler, perhaps neurally plausible, approximation to optimal decision-making. This conceptual link allows us to predict how the parameters of the race model, such as the stopping latency, should change with task parameters and individual experiences/ability.

  6. When is an Inhibitory Synapse Effective?

    Science.gov (United States)

    Qian, Ning; Sejnowski, Terrence J.

    1990-10-01

    Interactions between excitatory and inhibitory synaptic inputs on dendrites determine the level of activity in neurons. Models based on the cable equation predict that silent shunting inhibition can strongly veto the effect of an excitatory input. The cable model assumes that ionic concentrations do not change during the electrical activity, which may not be a valid assumption, especially for small structures such as dendritic spines. We present here an analysis and computer simulations to show that for large Cl^- conductance changes, the more general Nernst-Planck electrodiffusion model predicts that shunting inhibition on spines should be much less effective than that predicted by the cable model. This is a consequence of the large changes in the intracellular ionic concentration of Cl^- that can occur in small structures, which would alter the reversal potential and reduce the driving force for Cl^-. Shunting inhibition should therefore not be effective on spines, but it could be significantly more effective on the dendritic shaft at the base of the spine. In contrast to shunting inhibition, hyperpolarizing synaptic inhibition mediated by K^+ currents can be very effective in reducing the excitatory synaptic potentials on the same spine if the excitatory conductance change is less than 10 nS. We predict that if the inhibitory synapses found on cortical spines are to be effective, then they should be mediated by K^+ through GABA_B receptors.

  7. Rational Decision-Making in Inhibitory Control

    Science.gov (United States)

    Shenoy, Pradeep; Yu, Angela J.

    2011-01-01

    An important aspect of cognitive flexibility is inhibitory control, the ability to dynamically modify or cancel planned actions in response to changes in the sensory environment or task demands. We formulate a probabilistic, rational decision-making framework for inhibitory control in the stop signal paradigm. Our model posits that subjects maintain a Bayes-optimal, continually updated representation of sensory inputs, and repeatedly assess the relative value of stopping and going on a fine temporal scale, in order to make an optimal decision on when and whether to go on each trial. We further posit that they implement this continual evaluation with respect to a global objective function capturing the various reward and penalties associated with different behavioral outcomes, such as speed and accuracy, or the relative costs of stop errors and go errors. We demonstrate that our rational decision-making model naturally gives rise to basic behavioral characteristics consistently observed for this paradigm, as well as more subtle effects due to contextual factors such as reward contingencies or motivational factors. Furthermore, we show that the classical race model can be seen as a computationally simpler, perhaps neurally plausible, approximation to optimal decision-making. This conceptual link allows us to predict how the parameters of the race model, such as the stopping latency, should change with task parameters and individual experiences/ability. PMID:21647306

  8. Comparison of Heuristics for Inhibitory Rule Optimization

    KAUST Repository

    Alsolami, Fawaz

    2014-09-13

    Knowledge representation and extraction are very important tasks in data mining. In this work, we proposed a variety of rule-based greedy algorithms that able to obtain knowledge contained in a given dataset as a series of inhibitory rules containing an expression “attribute ≠ value” on the right-hand side. The main goal of this paper is to determine based on rule characteristics, rule length and coverage, whether the proposed rule heuristics are statistically significantly different or not; if so, we aim to identify the best performing rule heuristics for minimization of rule length and maximization of rule coverage. Friedman test with Nemenyi post-hoc are used to compare the greedy algorithms statistically against each other for length and coverage. The experiments are carried out on real datasets from UCI Machine Learning Repository. For leading heuristics, the constructed rules are compared with optimal ones obtained based on dynamic programming approach. The results seem to be promising for the best heuristics: the average relative difference between length (coverage) of constructed and optimal rules is at most 2.27% (7%, respectively). Furthermore, the quality of classifiers based on sets of inhibitory rules constructed by the considered heuristics are compared against each other, and the results show that the three best heuristics from the point of view classification accuracy coincides with the three well-performed heuristics from the point of view of rule length minimization.

  9. Assessment of inhibitory potential of essential oils on natural mycoflora and Fusarium mycotoxins production in wheat.

    Science.gov (United States)

    Sumalan, Renata-Maria; Alexa, Ersilia; Poiana, Mariana-Atena

    2013-02-14

    In the last years essential oils from different plants were used in the prevention of fungi and mycotoxins accumulation in cereals. The most attractive aspect derived from using of essential oils as seed grains protectants is due to their non-toxicity. This study was focused on assessment the inhibitory effect of some essential oils: Melissa officinalis (O1), Salvia officinalis (O2), Coriandrum sativum (O3), Thymus vulgaris (O4) Mentha piperita (O5) and Cinnamomum zeylanicum (O6) against natural mycoflora and Fusarium mycotoxins production correlated with their antioxidants properties. All essential oils showed inhibitory effect on fungal contamination of wheat seeds. This ability was dose-dependent. The highest inhibitory effect on Fusarium and Aspergillus fungi was recorded after 5 days of treatment. Fungi such as yeast (Pichia, Saccharomyces and Hyphopichia) were predominantly on seeds mycoflora after 22 days. Each treatment had a selective inhibitory effect on frequency of fungus genera. After 5 days of treatment the most fungicidal effect was recorder for O4, followed by O1. In terms of essential oils effect on mycotoxins development, the best control on fumonisins (FUMO) production was recorded for O6. The antioxidant properties of essential oils decreased in order: O4 > O1 > O6 > O5 > O2 > O3. Also, our data suggested that there is a significant negative correlation between antioxidant properties and seed contamination index (SCI), but there was not recorded a good correlation between antioxidant properties and FUMO content. Based on proven antifungal and antimycotoxin effects as well as their antioxidant properties, the essential oils could be recommended as natural preservatives for stored cereals. The highest inhibition of fungal growth was noted after 5 days of treatment and decreased after 22 days.

  10. Assessment of inhibitory potential of essential oils on natural mycoflora and Fusarium mycotoxins production in wheat

    Science.gov (United States)

    2013-01-01

    Background In the last years essential oils from different plants were used in the prevention of fungi and mycotoxins accumulation in cereals. The most attractive aspect derived from using of essential oils as seed grains protectants is due to their non-toxicity. This study was focused on assessment the inhibitory effect of some essential oils: Melissa officinalis (O1), Salvia officinalis (O2), Coriandrum sativum (O3), Thymus vulgaris (O4) Mentha piperita (O5) and Cinnamomum zeylanicum (O6) against natural mycoflora and Fusarium mycotoxins production correlated with their antioxidants properties. Results All essential oils showed inhibitory effect on fungal contamination of wheat seeds. This ability was dose-dependent. The highest inhibitory effect on Fusarium and Aspergillus fungi was recorded after 5 days of treatment. Fungi such as yeast (Pichia, Saccharomyces and Hyphopichia) were predominantly on seeds mycoflora after 22 days. Each treatment had a selective inhibitory effect on frequency of fungus genera. After 5 days of treatment the most fungicidal effect was recorder for O4, followed by O1. In terms of essential oils effect on mycotoxins development, the best control on fumonisins (FUMO) production was recorded for O6. The antioxidant properties of essential oils decreased in order: O4 > O1 > O6 > O5 > O2 > O3. Also, our data suggested that there is a significant negative correlation between antioxidant properties and seed contamination index (SCI), but there was not recorded a good correlation between antioxidant properties and FUMO content. Conclusions Based on proven antifungal and antimycotoxin effects as well as their antioxidant properties, the essential oils could be recommended as natural preservatives for stored cereals. The highest inhibition of fungal growth was noted after 5 days of treatment and decreased after 22 days. PMID:23409841

  11. Mechanisms underlying electrical and mechanical responses of the bovine retractor penis to inhibitory nerve stimulation and to an inhibitory extract.

    Science.gov (United States)

    Byrne, N. G.; Muir, T. C.

    1985-01-01

    The response of the bovine retractor penis (BRP) to stimulation of non-adrenergic, non-cholinergic (NANC) inhibitory nerves and to an inhibitory extract prepared from this muscle have been studied using intracellular microelectrode, sucrose gap and conventional mechanical recording techniques. Both inhibitory nerve stimulation and inhibitory extract hyperpolarized the membrane potential and relaxed spontaneous or guanethidine (3 X 10(-5) M)-induced tone. These effects were accompanied by an increase in membrane resistance. Following membrane potential displacement from an average value of -53 +/- 7 mV (n = 184; Byrne & Muir, 1984) inhibitory potentials to nerve stimulation were abolished at approximately -30 mV; there was no evidence of reversal. Displacement by inward hyperpolarizing current over the range -45 to -60 mV increased the inhibitory response to nerve stimulation and to inhibitory extract; at more negative potential values (above approximately -60 mV) the inhibitory potential decreased and was abolished (approximately -103 mV). There was no evidence of reversal. Removal of [K+]o reversibly reduced hyperpolarization to nerve stimulation and inhibitory extract. No enhancement was observed. Increasing the [K+]o to 20 mM reduced the inhibitory potential to nerve stimulation but this was restored by passive membrane hyperpolarization. Inhibitory potentials were obtained at membrane potential values exceeding that of the estimated EK (-49 mV). [Cl-]o-free or [Cl-]o-deficient solutions reduced and abolished (after some 20-25 min) the hyperpolarization produced by inhibitory nerve stimulation or inhibitory extract. The inhibitory potential amplitude following nerve stimulation was not restored by passive displacement of the membrane potential from -26 to -104 mV approximately. Ouabain (1-5 X 10(-5) M) reduced then (45-60 min later) abolished the inhibitory potential to nerve stimulation. The effects of this drug on the extract were not investigated. It is

  12. Matrix Metalloproteinase Enzyme Family

    Directory of Open Access Journals (Sweden)

    Ozlem Goruroglu Ozturk

    2013-04-01

    Full Text Available Matrix metalloproteinases play an important role in many biological processes such as embriogenesis, tissue remodeling, wound healing, and angiogenesis, and in some pathological conditions such as atherosclerosis, arthritis and cancer. Currently, 24 genes have been identified in humans that encode different groups of matrix metalloproteinase enzymes. This review discuss the members of the matrix metalloproteinase family and their substrate specificity, structure, function and the regulation of their enzyme activity by tissue inhibitors. [Archives Medical Review Journal 2013; 22(2.000: 209-220

  13. High throughtput comparisons and profiling of metagenomes for industrially relevant enzymes

    KAUST Repository

    Alam, Intikhab

    2016-01-01

    .g. temperature, environmental chemistry, etc… These metagenomes can be profiled to unearth enzymes relevant to several industries based on specific enzyme properties such as ability to work on extreme conditions, such as extreme temperatures, salinity

  14. Inhibitory Effect of Triterpenoids from Panax ginseng on Coagulation Factor X

    Directory of Open Access Journals (Sweden)

    Lingxin Xiong

    2017-04-01

    Full Text Available Enzymes involved in the coagulation process have received great attention as potential targets for the development of oral anti-coagulants. Among these enzymes, coagulation factor Xa (FXa has remained the center of attention in the last decade. In this study, 16 ginsenosides and two sapogenins were isolated, identified and quantified. To determine the inhibitory potential on FXa, the chromogenic substrates method was used. The assay suggested that compounds 5, 13 and 18 were mainly responsible for the anti-coagulant effect. Furthermore, these three compounds also possessed high thrombin selectivity in the thrombin inhibition assay. Furthermore, Glide XP from Schrödinger was employed for molecular docking to clarify the interaction between the bioactive compounds and FXa. Therefore, the chemical and biological results indicate that compounds 5 (ginsenoside Rg2, 13 (ginsenoside Rg3 and 18 (protopanaxtriol, PPT are potential natural inhibitors against FXa.

  15. Anti-idiotypic nanobody-alkaline phosphatase fusion proteins: Development of a one-step competitive enzyme immunoassay for fumonisin B{sub 1} detection in cereal

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Mei [State Key Laboratory of Food Science and Technology, Nanchang University, No. 235 Nanjing East Road, Nanchang 330047 (China); Jiangxi-OAI Joint Research Institute, Nanchang University, No. 235 Nanjing East Road, Nanchang 330047 (China); Xu, Yang, E-mail: xuyang@ncu.edu.cn [State Key Laboratory of Food Science and Technology, Nanchang University, No. 235 Nanjing East Road, Nanchang 330047 (China); Jiangxi-OAI Joint Research Institute, Nanchang University, No. 235 Nanjing East Road, Nanchang 330047 (China); Liu, Xing [State Key Laboratory of Food Science and Technology, Nanchang University, No. 235 Nanjing East Road, Nanchang 330047 (China); College of Food Science and Technology, Hainan University, No. 58 Renmin Avenue, Haikou 570228 (China); Li, Yanping; He, Qinghua [Jiangxi-OAI Joint Research Institute, Nanchang University, No. 235 Nanjing East Road, Nanchang 330047 (China); Tu, Zhui [State Key Laboratory of Food Science and Technology, Nanchang University, No. 235 Nanjing East Road, Nanchang 330047 (China); Fu, Jinheng [Jiangxi-OAI Joint Research Institute, Nanchang University, No. 235 Nanjing East Road, Nanchang 330047 (China); Gee, Shirley J.; Hammock, Bruce D. [Department of Entomology and UCD Comprehensive Cancer Center, University of California, Davis, CA 95616 (United States)

    2016-06-14

    A rapid and sensitive one-step competitive enzyme immunoassay for the detection of FB{sub 1} was developed. The anti-idiotypic nanobody–alkaline phosphatase (Ab2β−Nb−AP) was validated by the AP enzyme activity and the properties of bounding to anti-FB1-mAb (3F11) through colorimetric and chemiluminescence analyses. The 50% inhibitory concentration and the detection limit (LOD) of colorimetric enzyme-linked immunosorbent assay (ELISA) for FB{sub 1} were 2.69 and 0.35 ng mL{sup −1}, respectively, with a linear range of 0.93–7.73 ng mL{sup −1}. The LOD of the chemiluminescence ELISA (CLIA) was 0.12 ng mL{sup −1}, and the IC{sub 50} was 0.89 ± 0.09 ng mL{sup −1} with a linear range of 0.29–2.68 ng mL{sup −1}. Compared with LC-MS/MS, the results of this assay indicated the reliability of the Ab2β−Nb−AP fusion protein based one-step competitive immunoassay for monitoring FB{sub 1} contamination in cereals. The Ab2β−Nb−AP fusion proteins have the potential to replace chemically-coupled probes in competitive enzyme immunoassay systems. - Highlights: • Ab2β−Nb−AP has the potential to replace chemically-coupled probes. • Ab2β−Nb−AP is homogeneous enzyme-labelled antigen can be prepared reproducibly. • We developed a green and rapid one-step competitive enzyme immunoassay. • The sensitivity of one-step CLIA was 9-folds higher than two-step ELISA.

  16. Anti-idiotypic nanobody-alkaline phosphatase fusion proteins: Development of a one-step competitive enzyme immunoassay for fumonisin B_1 detection in cereal

    International Nuclear Information System (INIS)

    Shu, Mei; Xu, Yang; Liu, Xing; Li, Yanping; He, Qinghua; Tu, Zhui; Fu, Jinheng; Gee, Shirley J.; Hammock, Bruce D.

    2016-01-01

    A rapid and sensitive one-step competitive enzyme immunoassay for the detection of FB_1 was developed. The anti-idiotypic nanobody–alkaline phosphatase (Ab2β−Nb−AP) was validated by the AP enzyme activity and the properties of bounding to anti-FB1-mAb (3F11) through colorimetric and chemiluminescence analyses. The 50% inhibitory concentration and the detection limit (LOD) of colorimetric enzyme-linked immunosorbent assay (ELISA) for FB_1 were 2.69 and 0.35 ng mL"−"1, respectively, with a linear range of 0.93–7.73 ng mL"−"1. The LOD of the chemiluminescence ELISA (CLIA) was 0.12 ng mL"−"1, and the IC_5_0 was 0.89 ± 0.09 ng mL"−"1 with a linear range of 0.29–2.68 ng mL"−"1. Compared with LC-MS/MS, the results of this assay indicated the reliability of the Ab2β−Nb−AP fusion protein based one-step competitive immunoassay for monitoring FB_1 contamination in cereals. The Ab2β−Nb−AP fusion proteins have the potential to replace chemically-coupled probes in competitive enzyme immunoassay systems. - Highlights: • Ab2β−Nb−AP has the potential to replace chemically-coupled probes. • Ab2β−Nb−AP is homogeneous enzyme-labelled antigen can be prepared reproducibly. • We developed a green and rapid one-step competitive enzyme immunoassay. • The sensitivity of one-step CLIA was 9-folds higher than two-step ELISA.

  17. Macrophage migration inhibitory factor as an incriminating agent in vitiligo.

    Science.gov (United States)

    Farag, Azza Gaber Antar; Hammam, Mostafa Ahmed; Habib, Mona SalahEldeen; Elnaidany, Nada Farag; Kamh, Mona Eaid

    2018-03-01

    Vitiligo is an autoimmune skin disorder in which the loss of melanocytes is mainly attributed to defective autoimmune mechanisms and, lately, there has been more emphasis on autoinflammatory mediators. Among these is the macrophage migration inhibitory factor, which is involved in many autoimmune skin diseases. However, little is known about the contribution of this factor to vitiligo vulgaris. To determine the hypothesized role of migration inhibitory factor in vitiligo via estimation of serum migration inhibitory factor levels and migration inhibitory factor mRNA concentrations in patients with vitiligo compared with healthy controls. We also aimed to assess whether there is a relationship between the values of serum migration inhibitory factor and/or migration inhibitory factor mRNA with disease duration, clinical type and severity in vitiligo patients. Evaluation of migration inhibitory factor serum level and migration inhibitory factor mRNA expression by ELISA and real-time PCR, respectively, were performed for 50 patients with different degrees of vitiligo severity and compared to 15 age- and gender-matched healthy volunteers as controls. There was a highly significant increase in serum migration inhibitory factor and migration inhibitory factor mRNA levels in vitiligo cases when compared to controls (pvitiligo patients, and each of them with duration and severity of vitiligo. In addition, patients with generalized vitiligo have significantly elevated serum migration inhibitory factor and mRNA levels than control subjects. Small number of investigated subjects. Migration inhibitory factor may have an active role in the development of vitiligo, and it may also be a useful index of disease severity. Consequently, migration inhibitory factor may be a new treatment target for vitiligo patients.

  18. A Simple and Accurate Method for Measuring Enzyme Activity.

    Science.gov (United States)

    Yip, Din-Yan

    1997-01-01

    Presents methods commonly used for investigating enzyme activity using catalase and presents a new method for measuring catalase activity that is more reliable and accurate. Provides results that are readily reproduced and quantified. Can also be used for investigations of enzyme properties such as the effects of temperature, pH, inhibitors,…

  19. The surface science of enzymes

    DEFF Research Database (Denmark)

    Rod, Thomas Holm; Nørskov, Jens Kehlet

    2002-01-01

    One of the largest challenges to science in the coming years is to find the relation between enzyme structure and function. Can we predict which reactions an enzyme catalyzes from knowledge of its structure-or from its amino acid sequence? Can we use that knowledge to modify enzyme function......? To solve these problems we must understand in some detail how enzymes interact with reactants from its surroundings. These interactions take place at the surface of the enzyme and the question of enzyme function can be viewed as the surface science of enzymes. In this article we discuss how to describe...... catalysis by enzymes, and in particular the analogies between enzyme catalyzed reactions and surface catalyzed reactions. We do this by discussing two concrete examples of reactions catalyzed both in nature (by enzymes) and in industrial reactors (by inorganic materials), and show that although analogies...

  20. Gap junctions and inhibitory synapses modulate inspiratory motoneuron synchronization.

    Science.gov (United States)

    Bou-Flores, C; Berger, A J

    2001-04-01

    Interneuronal electrical coupling via gap junctions and chemical synaptic inhibitory transmission are known to have roles in the generation and synchronization of activity in neuronal networks. Uncertainty exists regarding the roles of these two modes of interneuronal communication in the central respiratory rhythm-generating system. To assess their roles, we performed studies on both the neonatal mouse medullary slice and en bloc brain stem-spinal cord preparations where rhythmic inspiratory motor activity can readily be recorded from both hypoglossal and phrenic nerve roots. The rhythmic inspiratory activity observed had two temporal characteristics: the basic respiratory frequency occurring on a long time scale and the synchronous neuronal discharge within the inspiratory burst occurring on a short time scale. In both preparations, we observed that bath application of gap-junction blockers, including 18 alpha-glycyrrhetinic acid, 18 beta-glycyrrhetinic acid, and carbenoxolone, all caused a reduction in respiratory frequency. In contrast, peak integrated phrenic and hypoglossal inspiratory activity was not significantly changed by gap-junction blockade. On a short-time-scale, gap-junction blockade increased the degree of synchronization within an inspiratory burst observed in both nerves. In contrast, opposite results were observed with blockade of GABA(A) and glycine receptors. We found that respiratory frequency increased with receptor blockade, and simultaneous blockade of both receptors consistently resulted in a reduction in short-time-scale synchronized activity observed in phrenic and hypoglossal inspiratory bursts. These results support the concept that the central respiratory system has two components: a rhythm generator responsible for the production of respiratory cycle timing and an inspiratory pattern generator that is involved in short-time-scale synchronization. In the neonatal rodent, properties of both components can be regulated by interneuronal

  1. Negative regulation of AMP-activated protein kinase (AMPK) activity by macrophage migration inhibitory factor (MIF) family members in non-small cell lung carcinomas.

    Science.gov (United States)

    Brock, Stephanie E; Rendon, Beatriz E; Yaddanapudi, Kavitha; Mitchell, Robert A

    2012-11-02

    AMP-activated protein kinase (AMPK) is a nutrient- and metabolic stress-sensing enzyme activated by the tumor suppressor kinase, LKB1. Because macrophage migration inhibitory factor (MIF) and its functional homolog, d-dopachrome tautomerase (d-DT), have protumorigenic functions in non-small cell lung carcinomas (NSCLCs) but have AMPK-activating properties in nonmalignant cell types, we set out to investigate this apparent paradox. Our data now suggest that, in contrast to MIF and d-DTs AMPK-activating properties in nontransformed cells, MIF and d-DT act cooperatively to inhibit steady-state phosphorylation and activation of AMPK in LKB1 wild type and LKB1 mutant human NSCLC cell lines. Our data further indicate that MIF and d-DT, acting through their shared cell surface receptor, CD74, antagonize NSCLC AMPK activation by maintaining glucose uptake, ATP production, and redox balance, resulting in reduced Ca(2+)/calmodulin-dependent kinase kinase β-dependent AMPK activation. Combined, these studies indicate that MIF and d-DT cooperate to inhibit AMPK activation in an LKB1-independent manner.

  2. Inhibitory Potential of Five Traditionally Used Native Antidiabetic Medicinal Plants on α-Amylase, α-Glucosidase, Glucose Entrapment, and Amylolysis Kinetics In Vitro

    Directory of Open Access Journals (Sweden)

    Carene M. N. Picot

    2014-01-01

    Full Text Available Five traditionally used antidiabetic native medicinal plants of Mauritius, namely, Stillingia lineata (SL, Faujasiopsis flexuosa (FF, Erythroxylum laurifolium (EL, Elaeodendron orientale (EO, and Antidesma madagascariensis (AM, were studied for possible α-amylase and α-glucosidase inhibitory property, glucose entrapment, and amylolysis kinetics in vitro. Only methanolic extracts of EL, EO, and AM (7472.92±5.99, 1745.58±31.66, and 2222.96±13.69 μg/mL, resp. were found to significantly (P<0.05 inhibit α-amylase and were comparable to acarbose. EL, EO, AM, and SL extracts (5000 μg/mL were found to significantly (P<0.05 inhibit α-glucosidase (between 87.41±3.31 and 96.87±1.37% inhibition. Enzyme kinetic studies showed an uncompetitive and mixed type of inhibition. Extracts showed significant (P<0.05 glucose entrapment capacities (8 to 29% glucose diffusion retardation index (GDRI, with SL being more active (29% GDRI and showing concentration-dependent activity (29, 26, 21, 14, and 5%, resp.. Amylolysis kinetic studies showed that methanolic extracts were more potent inhibitors of α-amylase compared to aqueous extracts and possessed glucose entrapment properties. Our findings tend to provide justification for the hypoglycaemic action of these medicinal plants which has opened novel avenues for the development of new phytopharmaceuticals geared towards diabetes management.

  3. Magnetically responsive enzyme powders

    Czech Academy of Sciences Publication Activity Database

    Pospišková, K.; Šafařík, Ivo

    2015-01-01

    Roč. 380, APR 2015 (2015), s. 197-200 ISSN 0304-8853 R&D Projects: GA MŠk(CZ) LD13021 Institutional support: RVO:67179843 Keywords : enzyme powders * cross-linking * magnetic modification * magnetic separation * magnetic iron oxides particles * microwave-assisted synthesis Subject RIV: CE - Biochemistry Impact factor: 2.357, year: 2015

  4. Enzyme with rhamnogalacturonase activity.

    NARCIS (Netherlands)

    Kofod, L.V.; Andersen, L.N.; Dalboge, H.; Kauppinen, M.S.; Christgau, S.; Heldt-Hansen, H.P.; Christophersen, C.; Nielsen, P.M.; Voragen, A.G.J.; Schols, H.A.

    1998-01-01

    An enzyme exhibiting rhamnogalacturonase activity, capable of cleaving a rhamnogalacturonan backbone in such a manner that galacturonic acids are left as the non-reducing ends, and which exhibits activity on hairy regions from a soy bean material and/or on saponified hairy regions from a sugar beet

  5. Implantable enzyme amperometric biosensors.

    Science.gov (United States)

    Kotanen, Christian N; Moussy, Francis Gabriel; Carrara, Sandro; Guiseppi-Elie, Anthony

    2012-05-15

    The implantable enzyme amperometric biosensor continues as the dominant in vivo format for the detection, monitoring and reporting of biochemical analytes related to a wide range of pathologies. Widely used in animal studies, there is increasing emphasis on their use in diabetes care and management, the management of trauma-associated hemorrhage and in critical care monitoring by intensivists in the ICU. These frontier opportunities demand continuous indwelling performance for up to several years, well in excess of the currently approved seven days. This review outlines the many challenges to successful deployment of chronically implantable amperometric enzyme biosensors and emphasizes the emerging technological approaches in their continued development. The foreign body response plays a prominent role in implantable biotransducer failure. Topics considering the approaches to mitigate the inflammatory response, use of biomimetic chemistries, nanostructured topographies, drug eluting constructs, and tissue-to-device interface modulus matching are reviewed. Similarly, factors that influence biotransducer performance such as enzyme stability, substrate interference, mediator selection and calibration are reviewed. For the biosensor system, the opportunities and challenges of integration, guided by footprint requirements, the limitations of mixed signal electronics, and power requirements, has produced three systems approaches. The potential is great. However, integration along the multiple length scales needed to address fundamental issues and integration across the diverse disciplines needed to achieve success of these highly integrated systems, continues to be a challenge in the development and deployment of implantable amperometric enzyme biosensor systems. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Advances in enzyme bioelectrochemistry

    Directory of Open Access Journals (Sweden)

    ANDRESSA R. PEREIRA

    Full Text Available ABSTRACT Bioelectrochemistry can be defined as a branch of Chemical Science concerned with electron-proton transfer and transport involving biomolecules, as well as electrode reactions of redox enzymes. The bioelectrochemical reactions and system have direct impact in biotechnological development, in medical devices designing, in the behavior of DNA-protein complexes, in green-energy and bioenergy concepts, and make it possible an understanding of metabolism of all living organisms (e.g. humans where biomolecules are integral to health and proper functioning. In the last years, many researchers have dedicated itself to study different redox enzymes by using electrochemistry, aiming to understand their mechanisms and to develop promising bioanodes and biocathodes for biofuel cells as well as to develop biosensors and implantable bioelectronics devices. Inside this scope, this review try to introduce and contemplate some relevant topics for enzyme bioelectrochemistry, such as the immobilization of the enzymes at electrode surfaces, the electron transfer, the bioelectrocatalysis, and new techniques conjugated with electrochemistry vising understand the kinetics and thermodynamics of redox proteins. Furthermore, examples of recent approaches in designing biosensors and biofuel developed are presented.

  7. Cold-Adapted Enzymes

    Science.gov (United States)

    Georlette, D.; Bentahir, M.; Claverie, P.; Collins, T.; D'amico, S.; Delille, D.; Feller, G.; Gratia, E.; Hoyoux, A.; Lonhienne, T.; Meuwis, M.-a.; Zecchinon, L.; Gerday, Ch.

    In the last few years, increased attention has been focused on enzymes produced by cold-adapted micro-organisms. It has emerged that psychrophilic enzymes represent an extremely powerful tool in both protein folding investigations and for biotechnological purposes. Such enzymes are characterised by an increased thermosensitivity and, most of them, by a higher catalytic efficiency at low and moderate temperatures, when compared to their mesophilic counterparts. The high thermosensitivity probably originates from an increased flexibility of either a selected area of the molecular edifice or the overall protein structure, providing enhanced abilities to undergo conformational changes during catalysis at low temperatures. Structure modelling and recent crystallographic data have allowed to elucidate the structural parameters that could be involved in this higher resilience. It was demonstrated that each psychrophilic enzyme adopts its own adaptive strategy. It appears, moreover, that there is a continuum in the strategy of protein adaptation to temperature, as the previously mentioned structural parameters are implicated in the stability of thermophilic proteins. Additional 3D crystal structures, site-directed and random mutagenesis experiments should now be undertaken to further investigate the stability-flexibility-activity relationship.

  8. Embedded enzymes catalyse capture

    Science.gov (United States)

    Kentish, Sandra

    2018-05-01

    Membrane technologies for carbon capture can offer economic and environmental advantages over conventional amine-based absorption, but can suffer from limited gas flux and selectivity to CO2. Now, a membrane based on enzymes embedded in hydrophilic pores is shown to exhibit combined flux and selectivity that challenges the state of the art.

  9. Photoperiodism and Enzyme Activity

    Science.gov (United States)

    Queiroz, Orlando; Morel, Claudine

    1974-01-01

    Metabolic readjustments after a change from long days to short days appear, in Kalanchoe blossfeldiana, to be achieved through the operation of two main mechanisms: variation in enzyme capacity, and circadian rhythmicity. After a lag time, capacity in phosphoenolpyruvate carboxylase and capacity in aspartate aminotransferase increase exponentially and appear to be allometrically linked during 50 to 60 short days; then a sudden fall takes place in the activity of the former. Malic enzyme and alanine aminotransferase behave differently. Thus, the operation of the two sections of the pathway (before and after the malate step) give rise to a continuously changing functional compartmentation in the pathway. Circadian rhythmicity, on the other hand, produces time compartmentation through phase shifts and variation in amplitude, independently for each enzyme. These characteristics suggest that the operation of a so-called biological clock would be involved. We propose the hypothesis that feedback regulation would be more accurate and efficient when applied to an already oscillating, clock-controlled enzyme system. PMID:16658749

  10. ISFET based enzyme sensors

    NARCIS (Netherlands)

    van der Schoot, Bart H.; Bergveld, Piet

    1987-01-01

    This paper reviews the results that have been reported on ISFET based enzyme sensors. The most important improvement that results from the application of ISFETs instead of glass membrane electrodes is in the method of fabrication. Problems with regard to the pH dependence of the response and the

  11. The Inhibitory Effect of Prunella vulgaris L. on Aldose Reductase and Protein Glycation

    Directory of Open Access Journals (Sweden)

    Hong Mei Li

    2012-01-01

    Full Text Available To evaluate the aldose reductase (AR enzyme inhibitory ability of Prunella vulgaris L. extract, six compounds were isolated and tested for their effects. The components were subjected to in vitro bioassays to investigate their inhibitory assays using rat lens aldose reductase (rAR and human recombinant AR (rhAR. Among them, caffeic acid ethylene ester showed the potent inhibition, with the IC50 values of rAR and rhAR at 3.2±0.55 μM and 12.58±0.32 μM, respectively. In the kinetic analyses using Lineweaver-Burk plots of 1/velocity and 1/concentration of substrate, this compound showed noncompetitive inhibition against rhAR. Furthermore, it inhibited galactitol formation in a rat lens incubated with a high concentration of galactose. Also it has antioxidative as well as advanced glycation end products (AGEs inhibitory effects. As a result, this compound could be offered as a leading compound for further study as a new natural products drug for diabetic complications.

  12. Coupling of guanine nucleotide inhibitory protein to somatostatin receptors on pancreatic acinar membranes

    International Nuclear Information System (INIS)

    Sakamoto, C.; Matozaki, T.; Nagao, M.; Baba, S.

    1987-01-01

    Guanine nucleotides and pertussis toxin were used to investigate whether somatostatin receptors interact with the guanine nucleotide inhibitory protein (NI) on pancreatic acinar membranes in the rat. Guanine nucleotides reduced 125 I-[Tyr 1 ]somatostatin binding to acinar membranes up to 80%, with rank order of potency being 5'-guanylyl imidodiphosphate [Gpp(NH)p]>GTP>TDP>GMP. Scatchard analysis revealed that the decrease in somatostatin binding caused by Gpp(NH)p was due to the decrease in the maximum binding capacity without a significant change in the binding affinity. The inhibitory effect of Gpp(NH)p was partially abolished in the absence of Mg 2+ . When pancreatic acini were treated with 1 μg/ml pertussis toxin for 4 h, subsequent 125 I-[Tyr 1 ]somatostatin binding to acinar membranes was reduced. Pertussis toxin treatment also abolished the inhibitory effect of somatostatin on vasoactive intestinal peptide-stimulated increase in cellular content of adenosine 3',5'-cyclic monophosphate (cAMP) in the acini. The present results suggest that 1) somatostatin probably functions in the pancreas to regulate adenylate cyclase enzyme system via Ni, 2) the extent of modification of Ni is correlated with the ability of somatostatin to inhibit cAMP accumulation in acini, and 3) guanine nucleotides also inhibit somatostatin binding to its receptor

  13. Do Children with Better Inhibitory Control Donate More? Differentiating between Early and Middle Childhood and Cool and Hot Inhibitory Control

    Directory of Open Access Journals (Sweden)

    Jian Hao

    2017-12-01

    Full Text Available Inhibitory control may play an important part in prosocial behavior, such as donating behavior. However, it is not clear at what developmental stage inhibitory control becomes associated with donating behavior and which aspects of inhibitory control are related to donating behavior during development in early to middle childhood. The present study aimed to clarify these issues with two experiments. In Experiment 1, 103 3- to 5-year-old preschoolers completed cool (Stroop-like and hot (delay of gratification inhibitory control tasks and a donating task. The results indicated that there were no relationships between cool or hot inhibitory control and donating behavior in the whole group and each age group of the preschoolers. In Experiment 2, 140 elementary school children in Grades 2, 4, and 6 completed cool (Stroop-like and hot (delay of gratification inhibitory control tasks and a donating task. The results showed that inhibitory control was positively associated with donating behavior in the whole group. Cool and hot inhibitory control respectively predicted donating behavior in the second and sixth graders. Therefore, the present study reveals that donating behavior increasingly relies on specific inhibitory control, i.e., hot inhibitory control as children grow in middle childhood.

  14. The Enzyme Function Initiative†

    Science.gov (United States)

    Gerlt, John A.; Allen, Karen N.; Almo, Steven C.; Armstrong, Richard N.; Babbitt, Patricia C.; Cronan, John E.; Dunaway-Mariano, Debra; Imker, Heidi J.; Jacobson, Matthew P.; Minor, Wladek; Poulter, C. Dale; Raushel, Frank M.; Sali, Andrej; Shoichet, Brian K.; Sweedler, Jonathan V.

    2011-01-01

    The Enzyme Function Initiative (EFI) was recently established to address the challenge of assigning reliable functions to enzymes discovered in bacterial genome projects; in this Current Topic we review the structure and operations of the EFI. The EFI includes the Superfamily/Genome, Protein, Structure, Computation, and Data/Dissemination Cores that provide the infrastructure for reliably predicting the in vitro functions of unknown enzymes. The initial targets for functional assignment are selected from five functionally diverse superfamilies (amidohydrolase, enolase, glutathione transferase, haloalkanoic acid dehalogenase, and isoprenoid synthase), with five superfamily-specific Bridging Projects experimentally testing the predicted in vitro enzymatic activities. The EFI also includes the Microbiology Core that evaluates the in vivo context of in vitro enzymatic functions and confirms the functional predictions of the EFI. The deliverables of the EFI to the scientific community include: 1) development of a large-scale, multidisciplinary sequence/structure-based strategy for functional assignment of unknown enzymes discovered in genome projects (target selection, protein production, structure determination, computation, experimental enzymology, microbiology, and structure-based annotation); 2) dissemination of the strategy to the community via publications, collaborations, workshops, and symposia; 3) computational and bioinformatic tools for using the strategy; 4) provision of experimental protocols and/or reagents for enzyme production and characterization; and 5) dissemination of data via the EFI’s website, enzymefunction.org. The realization of multidisciplinary strategies for functional assignment will begin to define the full metabolic diversity that exists in nature and will impact basic biochemical and evolutionary understanding, as well as a wide range of applications of central importance to industrial, medicinal and pharmaceutical efforts. PMID

  15. The Enzyme Function Initiative.

    Science.gov (United States)

    Gerlt, John A; Allen, Karen N; Almo, Steven C; Armstrong, Richard N; Babbitt, Patricia C; Cronan, John E; Dunaway-Mariano, Debra; Imker, Heidi J; Jacobson, Matthew P; Minor, Wladek; Poulter, C Dale; Raushel, Frank M; Sali, Andrej; Shoichet, Brian K; Sweedler, Jonathan V

    2011-11-22

    The Enzyme Function Initiative (EFI) was recently established to address the challenge of assigning reliable functions to enzymes discovered in bacterial genome projects; in this Current Topic, we review the structure and operations of the EFI. The EFI includes the Superfamily/Genome, Protein, Structure, Computation, and Data/Dissemination Cores that provide the infrastructure for reliably predicting the in vitro functions of unknown enzymes. The initial targets for functional assignment are selected from five functionally diverse superfamilies (amidohydrolase, enolase, glutathione transferase, haloalkanoic acid dehalogenase, and isoprenoid synthase), with five superfamily specific Bridging Projects experimentally testing the predicted in vitro enzymatic activities. The EFI also includes the Microbiology Core that evaluates the in vivo context of in vitro enzymatic functions and confirms the functional predictions of the EFI. The deliverables of the EFI to the scientific community include (1) development of a large-scale, multidisciplinary sequence/structure-based strategy for functional assignment of unknown enzymes discovered in genome projects (target selection, protein production, structure determination, computation, experimental enzymology, microbiology, and structure-based annotation), (2) dissemination of the strategy to the community via publications, collaborations, workshops, and symposia, (3) computational and bioinformatic tools for using the strategy, (4) provision of experimental protocols and/or reagents for enzyme production and characterization, and (5) dissemination of data via the EFI's Website, http://enzymefunction.org. The realization of multidisciplinary strategies for functional assignment will begin to define the full metabolic diversity that exists in nature and will impact basic biochemical and evolutionary understanding, as well as a wide range of applications of central importance to industrial, medicinal, and pharmaceutical efforts.

  16. Spectroscopic studies of copper enzymes

    International Nuclear Information System (INIS)

    Dooley, D.M.; Moog, R.; Zumft, W.; Koenig, S.H.; Scott, R.A.; Cote, C.E.; McGuirl, M.

    1986-01-01

    Several spectroscopic methods, including absorption, circular dichroism (CD), magnetic CD (MCD), X-ray absorption, resonance Raman, EPR, NMR, and quasi-elastic light-scattering spectroscopy, have been used to probe the structures of copper-containing amine oxidases, nitrite reductase, and nitrous oxide reductase. The basic goals are to determine the copper site structure, electronic properties, and to generate structure-reactivity correlations. Collectively, the results on the amine oxidases permit a detailed model for the Cu(II) sites in these enzymes to be constructed that, in turn, rationalizes the ligand-binding chemistry. Resonance Raman spectra of the phenylhydrazine and 2,4-dinitrophenyl-hydrazine derivatives of bovine plasma amine oxidase and models for its organic cofactor, e.g. pyridoxal, methoxatin, are most consistent with methoxatin being the intrinsic cofactor. The structure of the Cu(I) forms of the amine oxidases have been investigated by X-ray absorption spectroscopy (XAS); the copper coordination geometry is significantly different in the oxidized and reduced forms. Some anomalous properties of the amine oxidases in solution are explicable in terms of their reversible aggregation, which the authors have characterized via light scattering. Nitrite and nitrous oxide reductases display several novel spectral properties. The data suggest that new types of copper sites are present

  17. Free Radical Scavenging and Alpha/Beta-glucosidases Inhibitory Activities of Rambutan (Nephelium lappaceum L. Peel Extract

    Directory of Open Access Journals (Sweden)

    Wahyu Widowati

    2015-12-01

    Full Text Available BACKGROUND: Diabetes mellitus (DM is associated with oxidative reaction and hyperglycemic condition. Human body has an antioxidant defense system toward free radical, but overproduction of free radical causing imbalance condition between the free radical and the antioxidant defense in the body that lead to several diseases, including DM. Glucosidase is an enzyme that hydrolize carbohydrates causing increase of blood glucose level, so by inhibiting this enzyme blood glucose level in plasma could be effectively decreased. Rambutan (Nephelium lappaceum L. peel has been reported to have many potential roles, such as antioxidant and anti-glycemia. Therefore our current study was conducted to evaluate possible effectivity of Rambutan peel to scavenge free radical and to inhibit α- and β-glucosidases. METHODS: Rambutan peel extraction (RPE was performed based on maceration method. Geraniin was used as control. For antioxidant study, 2,2-diphenyl-1- picrylhydrazyl (DPPH free radical scavenging test was performed. For glucosidase inhibitory activity study,  α- and β-glucosidases inhibitory activity tests were performed. Results were analyzed for median of Inhibitory Concentration (IC50. RESULTS: The scavenging activity of RPE was comparable with Geraniin. Meanwhile, the α-glucosidase inhibitory activity of RPE was higher than the one of Geraniin. The α-glucosidase-inhibitory-activity IC50 of RPE and Geraniin were 0.106±0.080 μg/ml and 16.12±0.29 μg/ml, respectively. The β-glucosidase inhibitory activity of RPE was also higher than the one of Geraniin. The β-glucosidase-inhibitory-activity IC50 of RPE and Geraniin were 7.02±0.99 μg/ml and 19.81±0.66 μg/ml, respectively. CONCLUSIONS: Since RPE showed comparable free radical scavenging activity with Geraniin and higher α- and β-glucosidases inhibitory activities than Geraniin, RPE could be suggested as a promising antioxidant and antiglycemic agent.  KEYWORDS

  18. Nootropic dipeptide noopept enhances inhibitory synaptic transmission in the hippocampus.

    Science.gov (United States)

    Povarov, I S; Kondratenko, R V; Derevyagin, V I; Ostrovskaya, R U; Skrebitskii, V G

    2015-01-01

    Application of nootropic agent Noopept on hippocampal slices from Wistar rats enhanced the inhibitory component of total current induced by stimulation of Shaffer collaterals in CA1 pyramidal neurons, but did not affect the excitatory component. A direct correlation between the increase in the amplitude of inhibitory current and agent concentration was found. The substance did not affect the release of inhibitory transmitters from terminals in the pyramidal neurons, which indicated changes in GABAergic interneurons.

  19. Inhibitory Effect of Dried Pomegranate Concentration Powder on Melanogenesis in B16F10 Melanoma Cells; Involvement of p38 and PKA Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Su Jin Kang

    2015-10-01

    Full Text Available Plants rich in antioxidant substances may be useful for preventing skin aging. Pomegranates, containing flavonoids and other polyphenolic compounds, are widely consumed due to their beneficial properties. We examined the underlying mechanisms of dried pomegranate concentrate powder (PCP on melanin synthesis in B16F10 melanoma cells. The antioxidant effects of PCP were determined by measuring free radical scavenging capacity and transcript levels of antioxidant enzymes. To explore the inhibitory effects of PCP on melanin synthesis, we measured tyrosinase activity and melanin content in α-melanocyte stimulating hormone (α-MSH-stimulated B16F10 cells. In addition, the levels of tyrosinase-related protein-1 (TRP-1, TRP-2, tyrosinase, and microphthalmia-associated transcription factor (MITF expression were determined by Western blotting. Changes in the phosphorylation status of protein kinase A (PKA, cAMP response element-binding protein (CREB, mitogen-activated protein kinases (MAPKs, phosphatidylinositol 3-kinase (PI3K, serine/threonine kinase Akt, and glycogen kinase 3β (GSK3β were also examined. The free radical scavenging activity of PCP increased in a dose-dependent manner. In PCP-treated B16F10 cells, transcript levels of glutathione peroxidase-1 (GPx-1 were increased compared with α-MSH-stimulated cells. In addition, PCP led to the down-regulation of phospho-p38, phospho-PKA, phospho-CREB, phospho-GSK3β, MITF, and TRP-1 compared with α-MSH-stimulated B16F10 cells. We believe this effect may be associated with PCP activity, which leads to the inhibition of melanin production and tyrosinase activity. These results suggest that PCP decreases tyrosinase activity and melanin production via inactivation of the p38 and PKA signaling pathways, and subsequently decreases phosphorylation of CREB, MITF, and melanogenic enzymes. These observations provided new insights on the molecular mechanisms of the skin-whitening property of PCP.

  20. Inhibitory Effect of Dried Pomegranate Concentration Powder on Melanogenesis in B16F10 Melanoma Cells; Involvement of p38 and PKA Signaling Pathways

    Science.gov (United States)

    Kang, Su Jin; Choi, Beom Rak; Lee, Eun Kyoung; Kim, Seung Hee; Yi, Hae Yeon; Park, Hye Rim; Song, Chang Hyun; Lee, Young Joon; Ku, Sae Kwang

    2015-01-01

    Plants rich in antioxidant substances may be useful for preventing skin aging. Pomegranates, containing flavonoids and other polyphenolic compounds, are widely consumed due to their beneficial properties. We examined the underlying mechanisms of dried pomegranate concentrate powder (PCP) on melanin synthesis in B16F10 melanoma cells. The antioxidant effects of PCP were determined by measuring free radical scavenging capacity and transcript levels of antioxidant enzymes. To explore the inhibitory effects of PCP on melanin synthesis, we measured tyrosinase activity and melanin content in α-melanocyte stimulating hormone (α-MSH)-stimulated B16F10 cells. In addition, the levels of tyrosinase-related protein-1 (TRP-1), TRP-2, tyrosinase, and microphthalmia-associated transcription factor (MITF) expression were determined by Western blotting. Changes in the phosphorylation status of protein kinase A (PKA), cAMP response element-binding protein (CREB), mitogen-activated protein kinases (MAPKs), phosphatidylinositol 3-kinase (PI3K), serine/threonine kinase Akt, and glycogen kinase 3β (GSK3β) were also examined. The free radical scavenging activity of PCP increased in a dose-dependent manner. In PCP-treated B16F10 cells, transcript levels of glutathione peroxidase-1 (GPx-1) were increased compared with α-MSH-stimulated cells. In addition, PCP led to the down-regulation of phospho-p38, phospho-PKA, phospho-CREB, phospho-GSK3β, MITF, and TRP-1 compared with α-MSH-stimulated B16F10 cells. We believe this effect may be associated with PCP activity, which leads to the inhibition of melanin production and tyrosinase activity. These results suggest that PCP decreases tyrosinase activity and melanin production via inactivation of the p38 and PKA signaling pathways, and subsequently decreases phosphorylation of CREB, MITF, and melanogenic enzymes. These observations provided new insights on the molecular mechanisms of the skin-whitening property of PCP. PMID:26473849

  1. Functional properties of dioscorin, a soluble viscous protein from Japanese yam (Dioscorea opposita thunb.) tuber mucilage Tororo.

    Science.gov (United States)

    Nagai, Takeshi; Nagashima, Toshio

    2006-01-01

    A soluble viscous protein was purified from yam (Dioscorea opposita Thunb.) tuber mucilage tororo by chromatographic steps, and its functional properties were estimated. The purified dioscorin having the molecular weight of about 200 kDa exhibited high scavenging activities against hydroxyl radicals (IC50 = 195.1 microg/ml) and superoxide anion radicals (IC50 = 92.7 microg/ml). Moreover, it showed extremely high angiotensin I-converting enzyme inhibitory activity (IC50 = 41.1 microg/ml). The results suggested that yam D. opposita tuber has a wide spectrum of strong antioxidative and antihypertensive activities and it could be utilized as a source of natural antioxidant.

  2. Timing control by redundant inhibitory neuronal circuits

    Energy Technology Data Exchange (ETDEWEB)

    Tristan, I., E-mail: itristan@ucsd.edu; Rulkov, N. F.; Huerta, R.; Rabinovich, M. [BioCircuits Institute, University of California, San Diego, La Jolla, California 92093-0402 (United States)

    2014-03-15

    Rhythms and timing control of sequential activity in the brain is fundamental to cognition and behavior. Although experimental and theoretical studies support the understanding that neuronal circuits are intrinsically capable of generating different time intervals, the dynamical origin of the phenomenon of functionally dependent timing control is still unclear. Here, we consider a new mechanism that is related to the multi-neuronal cooperative dynamics in inhibitory brain motifs consisting of a few clusters. It is shown that redundancy and diversity of neurons within each cluster enhances the sensitivity of the timing control with the level of neuronal excitation of the whole network. The generality of the mechanism is shown to work on two different neuronal models: a conductance-based model and a map-based model.

  3. A recombinant wheat serpin with inhibitory activity

    DEFF Research Database (Denmark)

    Rasmussen, Søren K; Dahl, Søren Weis; Nørgård, Anette

    1996-01-01

    A full-length clone encoding the wheat (Triticum aestivum L.) serpin WSZ1 was isolated from a cDNA library based on mRNA from immature grain. The 398 amino acid sequence deduced from the cDNA was corroborated by sequencing CNBr peptides of WSZ1 purified from resting grain. WSZ1 belongs to the sub......A full-length clone encoding the wheat (Triticum aestivum L.) serpin WSZ1 was isolated from a cDNA library based on mRNA from immature grain. The 398 amino acid sequence deduced from the cDNA was corroborated by sequencing CNBr peptides of WSZ1 purified from resting grain. WSZ1 belongs...... sequencing indicated that only few serpins are encoded by wheat, but at least three distinct genes are expressed in the grain. Cleavage experiments on a chymotrypsin column suggested a Gln-Gln reactive site bond not previously observed in inhibitory serpins....

  4. Comparison of Heuristics for Inhibitory Rule Optimization

    KAUST Repository

    Alsolami, Fawaz; Chikalov, Igor; Moshkov, Mikhail

    2014-01-01

    Friedman test with Nemenyi post-hoc are used to compare the greedy algorithms statistically against each other for length and coverage. The experiments are carried out on real datasets from UCI Machine Learning Repository. For leading heuristics, the constructed rules are compared with optimal ones obtained based on dynamic programming approach. The results seem to be promising for the best heuristics: the average relative difference between length (coverage) of constructed and optimal rules is at most 2.27% (7%, respectively). Furthermore, the quality of classifiers based on sets of inhibitory rules constructed by the considered heuristics are compared against each other, and the results show that the three best heuristics from the point of view classification accuracy coincides with the three well-performed heuristics from the point of view of rule length minimization.

  5. Impaired inhibitory control in recreational cocaine users.

    Directory of Open Access Journals (Sweden)

    Lorenza S Colzato

    Full Text Available Chronic use of cocaine is associated with impairment in response inhibition but it is an open question whether and to which degree findings from chronic users generalize to the upcoming type of recreational users. This study compared the ability to inhibit and execute behavioral responses in adult recreational users and in a cocaine-free-matched sample controlled for age, race, gender distribution, level of intelligence, and alcohol consumption. Response inhibition and response execution were measured by a stop-signal paradigm. Results show that users and non users are comparable in terms of response execution but users need significantly more time to inhibit responses to stop-signals than non users. Interestingly, the magnitude of the inhibitory deficit was positively correlated with the individuals lifetime cocaine exposure suggesting that the magnitude of the impairment is proportional to the degree of cocaine consumed.

  6. Serum trypsin inhibitory capacity in hemodialysis patients

    International Nuclear Information System (INIS)

    Hashemi, Mohammad; Mehrabifar, Hamid; Homayooni, Fatemeh; Naderi, Mohammad; Montazerifar, Farzaneh; Ghavami, Saeid

    2009-01-01

    It has been established that overproduction of reactive oxygen species (ROS) occurs during hemodialysis causing oxidation of proteins. Alpha-1-antitrypsin is the major circulating anti-protease which contains methionine in the active site. The aim of the present study was to measure the level of serum trypsin inhibitory capacity (sTIC) in hemodialysis patients. This case-control study was performed in 52 hemodialysis patients and 49 healthy controls. sTIC was measured by enzymatic assay. The sTIC was significantly (P< 0.001) lower in hemodialysis patients (1.87 + - 0.67 micron mol/min/mL) than healthy controls (2.83 + - 0.44 micron mol/min/L). Reduction of sTIC may be due to the oxidation of methionine residue in the reactive site of alpha-1 antitrypsin. (author)

  7. Timing control by redundant inhibitory neuronal circuits

    International Nuclear Information System (INIS)

    Tristan, I.; Rulkov, N. F.; Huerta, R.; Rabinovich, M.

    2014-01-01

    Rhythms and timing control of sequential activity in the brain is fundamental to cognition and behavior. Although experimental and theoretical studies support the understanding that neuronal circuits are intrinsically capable of generating different time intervals, the dynamical origin of the phenomenon of functionally dependent timing control is still unclear. Here, we consider a new mechanism that is related to the multi-neuronal cooperative dynamics in inhibitory brain motifs consisting of a few clusters. It is shown that redundancy and diversity of neurons within each cluster enhances the sensitivity of the timing control with the level of neuronal excitation of the whole network. The generality of the mechanism is shown to work on two different neuronal models: a conductance-based model and a map-based model

  8. The biochemical anatomy of cortical inhibitory synapses.

    Directory of Open Access Journals (Sweden)

    Elizabeth A Heller

    Full Text Available Classical electron microscopic studies of the mammalian brain revealed two major classes of synapses, distinguished by the presence of a large postsynaptic density (PSD exclusively at type 1, excitatory synapses. Biochemical studies of the PSD have established the paradigm of the synapse as a complex signal-processing machine that controls synaptic plasticity. We report here the results of a proteomic analysis of type 2, inhibitory synaptic complexes isolated by affinity purification from the cerebral cortex. We show that these synaptic complexes contain a variety of neurotransmitter receptors, neural cell-scaffolding and adhesion molecules, but that they are entirely lacking in cell signaling proteins. This fundamental distinction between the functions of type 1 and type 2 synapses in the nervous system has far reaching implications for models of synaptic plasticity, rapid adaptations in neural circuits, and homeostatic mechanisms controlling the balance of excitation and inhibition in the mature brain.

  9. Nanoarmored Enzymes for Organic Enzymology: Synthesis and Characterization of Poly(2-Alkyloxazoline)-Enzyme Conjugates.

    Science.gov (United States)

    Leurs, Melanie; Tiller, Joerg C

    2017-01-01

    The properties of enzymes can be altered significantly by modification with polymers. Numerous different methods are known to obtain such polymer-enzyme conjugates (PECs). However, there is no universal method to render enzymes into PECs that are fully soluble in organic solvents. Here, we present a method, which achieves such high degree of modification of proteins that the majority of modified enzymes will be soluble in organic solvents. This is achieved by preparing poly(2-alkyloxazoline)s (POx) with an NH 2 end group and coupling this functional polymer via pyromellitic acid dianhydride onto the amino groups of the respective protein. The resulting PECs are capable of serving as surfactants for unmodified proteins, rendering the whole mixture organosoluble. Depending on the nature of the POx and the molecular weight and the nature of the enzyme, the PECs are soluble in chloroform or even toluene. Another advantage of this method is that the poly(2-alkyloxazoline) can be activated with the coupling agent and used for the enzyme conjugation without further purification. The POx-enzyme conjugates generated by this modification strategy show modulated catalytic activity in both, aqueous and organic, systems. © 2017 Elsevier Inc. All rights reserved.

  10. Antioxidant, xanthine oxidase and lipoxygenase inhibitory activities and phenolics of Bauhinia rufescens Lam. (Caesalpiniaceae).

    Science.gov (United States)

    Compaoré, M; Lamien, C E; Lamien-Meda, A; Vlase, L; Kiendrebeogo, M; Ionescu, C; Nacoulma, O G

    2012-01-01

    An aqueous acetone extract of the stem with the leaves of Bauhinia rufescens and its fractions were analysed for their antioxidant and enzyme-inhibitory activities, as well as their phytochemical composition. For measurement of the antioxidant activities, the 2,2-diphenyl-1-picrylhydrazyl, 2,2'-azinobis(3-ethylbenzoline-6-sulphonate) and the ferric-reducing methods were used. The results indicated that the aqueous acetone, its ethyl acetate and n-butanol fractions possessed considerable antioxidant activity. Further, the xanthine oxidase and lipoxygenase inhibitory assays showed that the n-butanol fraction possessed compounds that can inhibit both these enzymes. In the phytochemical analysis, the ethyl acetate and the n-butanol fractions of the aqueous acetone extract were screened by HPLC-MS for their phenolic content. The results indicated the presence of hyperoside, isoquercitrin, rutin quercetin, quercitrin, p-coumaric and ferulic acids in the non-hydrolysed fractions. In the hydrolysed fractions, kaempferol, p-coumaric and ferulic acids were identified.

  11. Hypocholesterolemic Effect and In Vitro Pancreatic Lipase Inhibitory Activity of an Opuntia ficus-indica Extract.

    Science.gov (United States)

    Padilla-Camberos, Eduardo; Flores-Fernandez, Jose Miguel; Fernandez-Flores, Ofelia; Gutierrez-Mercado, Yanet; Carmona-de la Luz, Joel; Sandoval-Salas, Fabiola; Mendez-Carreto, Carlos; Allen, Kirk

    2015-01-01

    Cholesterol control is fundamental for prevention of cardiovascular disorders. In this work, the hypocholesterolemic activity of an aqueous Opuntia ficus-indica extract (AOE) was tested in triton-induced mice. The inhibitory activity on pancreatic lipase enzyme was evaluated in vitro by the same extract. Furthermore, polyphenol content of the extract was evaluated. Hypercholesterolemia was induced in three groups of mice by intraperitoneal administration of Triton WR-1339. After induction of hypercholesterolemia, the groups were treated with an AOE (500 mg/kg) and saline solution and the positive control group with orlistat, respectively. Cholesterol levels were measured 24 h later in peripheral blood. The levels of blood cholesterol after administration of AOE significantly decreased compared to negative control. The inhibitory activity of AOE on pancreatic lipase enzyme was evaluated at concentrations from 60 to 1000 μg/mL. The AOE inhibited the pancreatic lipase with an IC50 = 588.5 μg/mL. The AOE had a high content of polyphenolic compounds. These results show that AOE is able to prevent hypercholesterolemia by pancreatic lipase inhibition, in part due to its polyphenolic compounds.

  12. Hypocholesterolemic Effect and In Vitro Pancreatic Lipase Inhibitory Activity of an Opuntia ficus-indica Extract

    Directory of Open Access Journals (Sweden)

    Eduardo Padilla-Camberos

    2015-01-01

    Full Text Available Cholesterol control is fundamental for prevention of cardiovascular disorders. In this work, the hypocholesterolemic activity of an aqueous Opuntia ficus-indica extract (AOE was tested in triton-induced mice. The inhibitory activity on pancreatic lipase enzyme was evaluated in vitro by the same extract. Furthermore, polyphenol content of the extract was evaluated. Hypercholesterolemia was induced in three groups of mice by intraperitoneal administration of Triton WR-1339. After induction of hypercholesterolemia, the groups were treated with an AOE (500 mg/kg and saline solution and the positive control group with orlistat, respectively. Cholesterol levels were measured 24 h later in peripheral blood. The levels of blood cholesterol after administration of AOE significantly decreased compared to negative control. The inhibitory activity of AOE on pancreatic lipase enzyme was evaluated at concentrations from 60 to 1000 μg/mL. The AOE inhibited the pancreatic lipase with an IC50 = 588.5 μg/mL. The AOE had a high content of polyphenolic compounds. These results show that AOE is able to prevent hypercholesterolemia by pancreatic lipase inhibition, in part due to its polyphenolic compounds.

  13. Recruitment of activation receptors at inhibitory NK cell immune synapses.

    Directory of Open Access Journals (Sweden)

    Nicolas Schleinitz

    2008-09-01

    Full Text Available Natural killer (NK cell activation receptors accumulate by an actin-dependent process at cytotoxic immune synapses where they provide synergistic signals that trigger NK cell effector functions. In contrast, NK cell inhibitory receptors, including members of the MHC class I-specific killer cell Ig-like receptor (KIR family, accumulate at inhibitory immune syna