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Sample records for inhibitory peptide fused

  1. Lactoferricin-related peptides with inhibitory effects on ACE-dependent vasoconstriction.

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

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    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.

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

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    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®

  4. Identification of dipeptidyl peptidase-IV inhibitory peptides from mare whey protein hydrolysates.

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    Song, J J; Wang, Q; Du, M; Ji, X M; Mao, X Y

    2017-09-01

    Inhibition of dipeptidyl peptidase-IV (DPP-IV) activity is a promising strategy for treatment of type 2 diabetes. In the current study, DPP-IV inhibitory peptides were identified from mare whey protein hydrolysates obtained by papain. The results showed that all the mare whey protein hydrolysates obtained at various hydrolysis durations possessed more potent DPP-IV inhibitory activity compared with intact whey protein. The 4-h hydrolysates showed the greatest DPP-IV inhibitory activity with half-maximal inhibitory concentration of 0.18 mg/mL. The 2 novel peptides from 4-h hydrolysate fractions separated by successive chromatographic steps were characterized by liquid chromatography-electrospray ionization tandem mass spectrometry. The novel peptides Asn-Leu-Glu-Ile-Ile-Leu-Arg and Thr-Gln-Met-Val-Asp-Glu-Glu-Ile-Met-Glu-Lys-Phe-Arg, which corresponded to β-lactoglobulin 1 f(71-77) and β-lactoglobulin 1 f(143-155), demonstrated DPP-IV inhibitory activity with half-maximal inhibitory concentrations of 86.34 and 69.84 μM, respectively. The DPP-IV inhibitory activity of the 2 peptides was retained or even improved after simulated gastrointestinal digestion in vitro. Our findings indicate that mare whey protein-derived peptides may possess potential as functional food ingredients in the management of type 2 diabetes. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  5. Myostatin inhibitory region of fish (Paralichthys olivaceus) myostatin-1 propeptide.

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    Lee, Sang Beum; Kim, Jeong Hwan; Jin, Deuk-Hee; Jin, Hyung-Joo; Kim, Yong Soo

    2016-01-01

    Myostatin (MSTN) is a potent negative regulator of skeletal muscle growth, and its activity is suppressed by MSTN propeptide (MSTNpro), the N-terminal part of MSTN precursor cleaved during post-translational MSTN processing. The current study examined which region of flatfish (Paralichthys olivaceus) MSTN-1 propeptide (MSTN1pro) is critical for MSTN inhibition. Six different truncated forms of MSTN1pro containing N-terminal maltose binding protein (MBP) as a fusion partner were expressed in Escherichia coli, and partially purified by an affinity chromatography for MSTN-inhibitory activity examination. Peptides covering different regions of flatfish MSTN1pro were also synthesized for MSTN-inhibitory activity examination. A MBP-fused MSTN1pro region consisting of residues 45-100 had the same MSTN-inhibitory potency as the full sequence flatfish MSTN1pro (residues 23-265), indicating that the region of flatfish MSTN1pro consisting of residues 45-100 is sufficient to maintain the full MSTN-inhibitory capacity. A MBP-fused MSTN1pro region consisting of residues 45-80 (Pro45-80) also showed MSTN-inhibitory activity with a lower potency, and the Pro45-80 demonstrated its MSTN binding capacity in a pull-down assay, indicating that the MSTN-inhibitory capacity of Pro45-80 is due to its binding to MSTN. Flatfish MSTN1pro synthetic peptides covering residues 45-65, 45-70, and 45-80 demonstrated MSTN-inhibitory activities, but not the synthetic peptide covering residues 45-54, indicating that residues 45-65 of flatfish MSTN1pro are essential for MSTN inhibition. In conclusion, current study show that like the mammalian MSTNpro, the MSTN-inhibitory region of flatfish MSTN1pro resides near its N-terminus, and imply that smaller sizes of MSTNpro can be effectively used in various applications designed for MSTN inhibition. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Preparation of ACE Inhibitory Peptides from Mytilus coruscus Hydrolysate Using Uniform Design

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    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.

  7. Expression of the cationic antimicrobial peptide lactoferricin fused with the anionic peptide in Escherichia coli.

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    Kim, Ha-Kun; Chun, Dae-Sik; Kim, Joon-Sik; Yun, Cheol-Ho; Lee, Ju-Hoon; Hong, Soon-Kwang; Kang, Dae-Kyung

    2006-09-01

    Direct expression of lactoferricin, an antimicrobial peptide, is lethal to Escherichia coli. For the efficient production of lactoferricin in E. coli, we developed an expression system in which the gene for the lysine- and arginine-rich cationic lactoferricin was fused to an anionic peptide gene to neutralize the basic property of lactoferricin, and successfully overexpressed the concatemeric fusion gene in E. coli. The lactoferricin gene was linked to a modified magainin intervening sequence gene by a recombinational polymerase chain reaction, thus producing an acidic peptide-lactoferricin fusion gene. The monomeric acidic peptide-lactoferricin fusion gene was multimerized and expressed in E. coli BL21(DE3) upon induction with isopropyl-beta-D-thiogalactopyranoside. The expression levels of the fusion peptide reached the maximum at the tetramer, while further increases in the copy number of the fusion gene substantially reduced the peptide expression level. The fusion peptides were isolated and cleaved to generate the separate lactoferricin and acidic peptide. About 60 mg of pure recombinant lactoferricin was obtained from 1 L of E. coli culture. The purified recombinant lactoferricin was found to have a molecular weight similar to that of chemically synthesized lactoferricin. The recombinant lactoferricin showed antimicrobial activity and disrupted bacterial membrane permeability, as the native lactoferricin peptide does.

  8. Identification of novel dipeptidyl peptidase IV (DPP-IV) inhibitory peptides in camel milk protein hydrolysates.

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    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.

  9. Isolation of prolyl endopeptidase inhibitory peptides from a sodium caseinate hydrolysate.

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    Hsieh, Cheng-Hong; Wang, Tzu-Yuan; Hung, Chuan-Chuan; Hsieh, You-Liang; Hsu, Kuo-Chiang

    2016-01-01

    Prolyl endopeptidase (PEP) has been associated with neurodegenerative disorders, and the PEP inhibitors can restore the memory loss caused by amnesic compounds. In this study, we investigated the PEP inhibitory activity of the enzymatic hydrolysates from various food protein sources, and isolated and identified the PEP inhibitory peptides. The hydrolysate obtained from sodium caseinate using bromelain (SC/BML) displayed the highest inhibitory activity of 86.8% at 5 mg mL(-1) in the present study, and its IC50 value against PEP was 0.77 mg mL(-1). The F-5 fraction by RP-HPLC (reversed-phase high performance liquid chromatography) from SC/BML showed the highest PEP inhibition rate of 88.4%, and 9 peptide sequences were identified. The synthetic peptides (1245.63-1787.94 Da) showed dose-dependent inhibition effects on PEP as competitive inhibitors with IC50 values between 29.8 and 650.5 μM. The results suggest that the peptides derived from sodium caseinate have the potential to be PEP inhibitors.

  10. Effect of N-Terminal Acylation on the Activity of Myostatin Inhibitory Peptides.

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    Takayama, Kentaro; Nakamura, Akari; Rentier, Cédric; Mino, Yusaku; Asari, Tomo; Saga, Yusuke; Taguchi, Akihiro; Yakushiji, Fumika; Hayashi, Yoshio

    2016-04-19

    Inhibition of myostatin, which negatively regulates skeletal muscle growth, is a promising strategy for the treatment of muscle atrophic disorders, such as muscular dystrophy, cachexia and sarcopenia. Recently, we identified peptide A (H-WRQNTRYSRIEAIKIQILSKLRL-NH2 ), the 23-amino-acid minimum myostatin inhibitory peptide derived from mouse myostatin prodomain, and highlighted the importance of its N-terminal tryptophan residue for the effective inhibition. In this study, we synthesized a series of acylated peptide derivatives focused on the tryptophan residue to develop potent myostatin inhibitors. As a result of the investigation, a more potent derivative of peptide A was successfully identified in which the N-terminal tryptophan residue is replaced with a 2-naphthyloxyacetyl moiety to give an inhibitory peptide three times (1.19±0.11 μm) more potent than parent peptide A (3.53±0.25 μm). This peptide could prove useful as a new starting point for the development of improved inhibitory peptides. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

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    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.

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

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    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.

  13. 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.

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

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    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.

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

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    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.

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

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    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.

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

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    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.

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

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    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.

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

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    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

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

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    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.

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

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    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.

  2. Production of antioxidant and ACE-inhibitory peptides from Kluyveromyces marxianus protein hydrolysates: Purification and molecular docking

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    Mahta Mirzaei

    2018-04-01

    Full Text Available Kluyveromyces marxianus protein hydrolysates were prepared by two different sonicated-enzymatic (trypsin and chymotrypsin hydrolysis treatments to obtain antioxidant and ACE-inhibitory peptides. Trypsin and chymotrypsin hydrolysates obtained by 5 h, exhibited the highest antioxidant and ACE-inhibitory activities. After fractionation using ultrafiltration and reverse phase high performance liquid chromatography (RP-HPLC techniques, two new peptides were identified. One fragment (LL-9, MW = 1180 Da with the amino acid sequence of Leu-Pro-Glu-Ser-Val-His-Leu-Asp-Lys showed significant ACE inhibitory activity (IC50 = 22.88 μM while another peptide fragment (VL-9, MW = 1118 Da with the amino acid sequence of Val-Leu-Ser-Thr-Ser-Phe-Pro-Pro-Lys showed the highest antioxidant and ACE inhibitory properties (IC50 = 15.20 μM, 5568 μM TE/mg protein. The molecular docking studies revealed that the ACE inhibitory activities of VL-9 is due to interaction with the S2 (His513, His353, Glu281 and S′1 (Glu162 pockets of ACE and LL-9 can fit perfectly into the S1 (Thr345 and S2 (Tyr520, Lys511, Gln281 pockets of ACE. Keywords: K. marxianus, Bioactive peptides, Antioxidant, ACE inhibitory, Protein hydrolysate

  3. Signal-BNF: A Bayesian Network Fusing Approach to Predict Signal Peptides

    Directory of Open Access Journals (Sweden)

    Zhi Zheng

    2012-01-01

    Full Text Available A signal peptide is a short peptide chain that directs the transport of a protein and has become the crucial vehicle in finding new drugs or reprogramming cells for gene therapy. As the avalanche of new protein sequences generated in the postgenomic era, the challenge of identifying new signal sequences has become even more urgent and critical in biomedical engineering. In this paper, we propose a novel predictor called Signal-BNF to predict the N-terminal signal peptide as well as its cleavage site based on Bayesian reasoning network. Signal-BNF is formed by fusing the results of different Bayesian classifiers which used different feature datasets as its input through weighted voting system. Experiment results show that Signal-BNF is superior to the popular online predictors such as Signal-3L and PrediSi. Signal-BNF is featured by high prediction accuracy that may serve as a useful tool for further investigating many unclear details regarding the molecular mechanism of the zip code protein-sorting system in cells.

  4. Identification and Characterization of a Small Inhibitory Peptide That Can Target DNA-PKcs Autophosphorylation and Increase Tumor Radiosensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Sun Xiaonan [Department of Radiation Oncology, Sir Run Run Shaw Hospital, Sir Run Run Shaw Institute of Clinical Medicine of Zhejiang University, Hangzhou (China); Yang Chunying [Department of Radiation Oncology, Methodist Hospital Research Institute, Weill Cornell Medical College, Houston, TX (United States); Liu Hai; Wang Qi [Department of Radiation Oncology, Sir Run Run Shaw Hospital, Sir Run Run Shaw Institute of Clinical Medicine of Zhejiang University, Hangzhou (China); Wu Shixiu [Department of Radiation Oncology, The First Affiliated Hospital of Wenzhou Medical College, Wenzhou (China); Li Xia; Xie Tian [Research Center of Biomedicine and Health, Hangzhou Normal University, Hangzhou (China); Brinkman, Kathryn L.; Teh, Bin S.; Butler, E. Brian [Department of Radiation Oncology, Methodist Hospital Research Institute, Weill Cornell Medical College, Houston, TX (United States); Xu Bo, E-mail: bxu@tmhs.org [Department of Radiation Oncology, Methodist Hospital Research Institute, Weill Cornell Medical College, Houston, TX (United States); Zheng, Shu, E-mail: zhengshu@zju.edu.cn [Cancer Institute, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou (China)

    2012-12-01

    Purpose: The DNA protein kinase catalytic subunit (DNA-PKcs) is one of the critical elements involved in the DNA damage repair process. Inhibition of DNA-PKcs results in hypersensitivity to ionizing radiation (IR); therefore, this approach has been explored to develop molecular targeted radiosensitizers. Here, we aimed to develop small inhibitory peptides that could specifically target DNA-PKcs autophosphorylation, a critical step for the enzymatic activation of the kinase in response to IR. Methods and Materials: We generated several small fusion peptides consisting of 2 functional domains, 1 an internalization domain and the other a DNA-PKcs autophosphorylation inhibitory domain. We characterized the internalization, toxicity, and radiosensitization activities of the fusion peptides. Furthermore, we studied the mechanisms of the inhibitory peptides on DNA-PKcs autophosphorylation and DNA repair. Results: We found that among several peptides, the biotin-labeled peptide 3 (BTW3) peptide, which targets DNA-PKcs threonine 2647 autophosphorylation, can abrogate IR-induced DNA-PKcs activation and cause prolonged {gamma}-H2AX focus formation. We demonstrated that BTW3 exposure led to hypersensitivity to IR in DNA-PKcs-proficient cells but not in DNA-PKcs-deficient cells. Conclusions: The small inhibitory peptide BTW3 can specifically target DNA-PKcs autophosphorylation and enhance radiosensitivity; therefore, it can be further developed as a novel class of radiosensitizer.

  5. Identification and Characterization of a Small Inhibitory Peptide That Can Target DNA-PKcs Autophosphorylation and Increase Tumor Radiosensitivity

    International Nuclear Information System (INIS)

    Sun Xiaonan; Yang Chunying; Liu Hai; Wang Qi; Wu Shixiu; Li Xia; Xie Tian; Brinkman, Kathryn L.; Teh, Bin S.; Butler, E. Brian; Xu Bo; Zheng, Shu

    2012-01-01

    Purpose: The DNA protein kinase catalytic subunit (DNA-PKcs) is one of the critical elements involved in the DNA damage repair process. Inhibition of DNA-PKcs results in hypersensitivity to ionizing radiation (IR); therefore, this approach has been explored to develop molecular targeted radiosensitizers. Here, we aimed to develop small inhibitory peptides that could specifically target DNA-PKcs autophosphorylation, a critical step for the enzymatic activation of the kinase in response to IR. Methods and Materials: We generated several small fusion peptides consisting of 2 functional domains, 1 an internalization domain and the other a DNA-PKcs autophosphorylation inhibitory domain. We characterized the internalization, toxicity, and radiosensitization activities of the fusion peptides. Furthermore, we studied the mechanisms of the inhibitory peptides on DNA-PKcs autophosphorylation and DNA repair. Results: We found that among several peptides, the biotin-labeled peptide 3 (BTW3) peptide, which targets DNA-PKcs threonine 2647 autophosphorylation, can abrogate IR-induced DNA-PKcs activation and cause prolonged γ-H2AX focus formation. We demonstrated that BTW3 exposure led to hypersensitivity to IR in DNA-PKcs-proficient cells but not in DNA-PKcs-deficient cells. Conclusions: The small inhibitory peptide BTW3 can specifically target DNA-PKcs autophosphorylation and enhance radiosensitivity; therefore, it can be further developed as a novel class of radiosensitizer.

  6. Inhibitory mechanism of peptides and antibodies targeting murine urokinase-type plasminogen activator

    DEFF Research Database (Denmark)

    Liu, Zhuo

    2012-01-01

    drugs, a detailed mechanistic understanding must be obtained. One peptide and two antibodies were studied in this thesis. First, an engineered cyclic peptide, mupain-1-16 with an unnatural amino acid in the P1 position and the sequence CPAYS[L-3-(N-Amidino-4-piperidyl)alanine]YLDC was investigated...... different conformational and inhibitory mechanisms both in vivo and in vitro. Their similar epitopes, but different functions revealed two different allosteric regulation mechanisms for antibodies binding to serine proteases. Both the peptidic inhibitors and the allosteric mechanisms of uPA are believed...

  7. Enhancement of thermo-stability and product tolerance of Pseudomonas putida nitrile hydratase by fusing with self-assembling peptide.

    Science.gov (United States)

    Liu, Yi; Cui, Wenjing; Liu, Zhongmei; Cui, Youtian; Xia, Yuanyuan; Kobayashi, Michihiko; Zhou, Zhemin

    2014-09-01

    Self-assembling amphipathic peptides (SAPs) are the peptides that can spontaneously assemble into ordered nanostructures. It has been reported that the attachment of SAPs to the N- or C-terminus of an enzyme can benefit the thermo-stability of the enzyme. Here, we discovered that the thermo-stability and product tolerance of nitrile hydratase (NHase) were enhanced by fusing with two of the SAPs (EAK16 and ELK16). When the ELK16 was fused to the N-terminus of β-subunit, the resultant NHase (SAP-NHase-2) became an active inclusion body; EAK16 fused NHase in the N-terminus of β-subunit (SAP-NHase-1) and ELK16 fused NHase in the C-terminus of β-subunit (SAP-NHase-10) did not affect NHase solubility. Compared with the deactivation of the wild-type NHase after 30 min incubation at 50°C, SAP-NHase-1, SAP-NHase-2 and SAP-NHase-10 retained 45%, 30% and 50% activity; after treatment in the buffer containing 10% acrylamide, the wild-type retained 30% activity, while SAP-NHase-1, SAP-NHase-2 and SAP-NHase-10 retained 52%, 42% and 55% activity. These SAP-NHases with enhanced thermo-stability and product tolerance would be helpful for further industrial applications of the NHase. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  8. 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®.

  9. 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

  10. 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.

  11. Heterologous expression of enterocin A, a bacteriocin from Enterococcus faecium, fused to a cellulose-binding domain in Escherichia coli results in a functional protein with inhibitory activity against Listeria.

    Science.gov (United States)

    Klocke, Michael; Mundt, Kerstin; Idler, Frank; Jung, Sabrina; Backhausen, Jan E

    2005-06-01

    The genes for the bacteriocins enterocin A and B were isolated from Enterococcus faecium ATB 197a. Using the pET37b(+) vector, the enterocin genes were fused to an Escherichia coli specific export signal sequence, a cellulose-binding domain (CBD(cenA)) and a S-tag under the control of a T7lac promotor. The constructs were subsequently cloned into E. coli host cells. The expression of the recombinant enterocins had different effects on both the host cells and other Gram-positive bacteria. The expression of entA in Esc. coli led to the synthesis and secretion of functional active enterocin A fusion proteins, which were active against some Gram-positive indicator bacteria, but did not influence the viability of the host cells. In contrast, the expression of enterocin B fusion proteins led to a reduced viability of the host cells, indicating a misfolding of the protein or interference with the cellular metabolism of Esc. coli. Indicator strains of Gram-positive bacteria were not inhibited by purified enterocin B fusion proteins. However, recombinant enterocin B displayed inhibitory activity after the proteolytic cleavage of the fused peptides.

  12. 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.

  13. 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.

  14. 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.

  15. 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...

  16. 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

  17. 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

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. New ACE-Inhibitory Peptides from Hemp Seed (Cannabis sativa L.) Proteins.

    Science.gov (United States)

    Orio, Lara P; Boschin, Giovanna; Recca, Teresa; Morelli, Carlo F; Ragona, Laura; Francescato, Pierangelo; Arnoldi, Anna; Speranza, Giovanna

    2017-12-06

    A hemp seed protein isolate, prepared from defatted hemp seed meals by alkaline solubilization/acid precipitation, was subjected to extensive chemical hydrolysis under acid conditions (6 M HCl). The resulting hydrolysate was fractionated by semipreparative RP-HPLC, and the purified fractions were tested as inhibitors of angiotensin converting enzyme (ACE). Mono- and bidimensional NMR experiments and LC-MS analyses led to the identification of four potentially bioactive peptides, i.e. GVLY, IEE, LGV, and RVR. They were prepared by solid-phase synthesis, and tested for ACE-inhibitory activity. The IC 50 values were GVLY 16 ± 1.5 μM, LGV 145 ± 13 μM, and RVR 526 ± 33 μM, confirming that hemp seed may be a valuable source of hypotensive peptides.

  3. An in vitro study of peptide-loaded alginate nanospheres for antagonizing the inhibitory effect of Nogo-A protein on axonal growth

    International Nuclear Information System (INIS)

    Zhai, Peng; Chen, X B; Schreyer, David J

    2015-01-01

    The adult mammalian central nervous system has limited ability to regenerate after injury. This is due, in part, to the presence of myelin-associated axon growth inhibitory proteins such as Nogo-A that bind and activate the Nogo receptor, leading to profound inhibition of actin-based motility within the growing axon tip. This paper presents an in vitro study of the use of a Nogo receptor-blocking peptide to antagonize the inhibitory effect of Nogo-A on axon growth. Alginate nanospheres were fabricated using an emulsion technique and loaded with Nogo receptor-blocking peptide, or with other model proteins. Protein release profiles were studied, and retention of the bioactivity of released proteins was verified. Primary dorsal root ganglion neurons were cultured and their ability to grow neurites was challenged with Nogo-A chimeric protein in the absence or presence of Nogo receptor antagonist peptide-loaded alginate nanospheres. Our results demonstrate that peptide released from alginate nanospheres could overcome the growth inhibitory effect of Nogo-A, suggesting that a similar peptide delivery strategy using alginate nanospheres might be used to improve axon regeneration within the injured central nervous system. (paper)

  4. Optimization of Nutrient Composition for Producing ACE Inhibitory Peptides from Goat Milk Fermented by Lactobacillus bulgaricus LB6.

    Science.gov (United States)

    Shu, Guowei; Shi, Xiaoyu; Chen, He; Ji, Zhe; Meng, Jiangpeng

    2018-03-23

    Hypertension is a serious threat to human health and food-derived angiotensin converting enzyme (ACE; EC 3.4.15.1) inhibitory peptides can be used to regulate high blood pressure without side effects. The composition of the nutrient medium for the production of these peptides by fermenting goat milk with Lactobacillus bulgaricus LB6 was optimized to increase the ACE inhibitory activity by Box-Behnken design (BBD) of response surface methodology (RSM) in the present study. Soybean peptone, glucose, and casein had significant effects on both ACE inhibition rate and viable counts of L. bulgaricus LB6 during incubation. The results showed that the maximum values of ACE inhibition rate and viable counts for L. bulgaricus LB6 were reaching to 86.37 ± 0.53% and 8.06 × 10 7 under the optimal conditions, which were 0.35% (w/w) soybean peptone, 1.2% (w/w) glucose, and 0.15% (w/w) casein. The results were in close agreement with the model prediction. The optimal values of the medium component concentrations can be a good reference for obtaining ACE inhibitory peptides from goat milk.

  5. Chlorotoxin Fused to IgG-Fc Inhibits Glioblastoma Cell Motility via Receptor-Mediated Endocytosis

    Directory of Open Access Journals (Sweden)

    Tomonari Kasai

    2012-01-01

    Full Text Available Chlorotoxin is a 36-amino acid peptide derived from Leiurus quinquestriatus (scorpion venom, which has been shown to inhibit low-conductance chloride channels in colonic epithelial cells. Chlorotoxin also binds to matrix metalloproteinase-2 and other proteins on glioma cell surfaces. Glioma cells are considered to require the activation of matrix metalloproteinase-2 during invasion and migration. In this study, for targeting glioma, we designed two types of recombinant chlorotoxin fused to human IgG-Fcs with/without a hinge region. Chlorotoxin fused to IgG-Fcs was designed as a dimer of 60 kDa with a hinge region and a monomer of 30 kDa without a hinge region. The monomeric and dimeric forms of chlorotoxin inhibited cell proliferation at 300 nM and induced internalization in human glioma A172 cells. The monomer had a greater inhibitory effect than the dimer; therefore, monomeric chlorotoxin fused to IgG-Fc was multivalently displayed on the surface of bionanocapsules to develop a drug delivery system that targeted matrix metalloproteinase-2. The target-dependent internalization of bionanocapsules in A172 cells was observed when chlorotoxin was displayed on the bionanocapsules. This study indicates that chlorotoxin fused to IgG-Fcs could be useful for the active targeting of glioblastoma cells.

  6. Egg-yolk protein by-product as a source of ACE-inhibitory peptides obtained with using unconventional proteinase from Asian pumpkin (Cucurbita ficifolia).

    Science.gov (United States)

    Eckert, Ewelina; Zambrowicz, Aleksandra; Pokora, Marta; Setner, Bartosz; Dąbrowska, Anna; Szołtysik, Marek; Szewczuk, Zbigniew; Polanowski, Antoni; Trziszka, Tadeusz; Chrzanowska, Józefa

    2014-10-14

    In the present study angiotensin I-converting enzyme (ACE) inhibitory peptides were isolated from egg-yolk protein preparation (YP). Enzymatic hydrolysis conducted using unconventional enzyme from Cucurbita ficifolia (dose: 1000 U/mg of hydrolyzed YP (E/S (w/w)=1:7.52)) was employed to obtain protein hydrolysates. The 4-h hydrolysate exhibited a significant (IC₅₀=482.5 μg/mL) ACE inhibitory activity. Moreover, hydrolysate showed no cytotoxic activity on human and animal cell lines which makes it a very useful multifunctional method for peptide preparation. The compiled isolation procedure (ultrafiltration, size-exclusion chromatography and RP-HPLC) of bioactive peptides from YP hydrolysate resulted in obtaining peptides with the strong ACE inhibitory activity. One homogeneous and three heterogeneous peptide fractions were identified. The peptides were composed of 9-18 amino-acid residues, including mainly arginine and leucine at the N-terminal positions. To confirm the selected bioactive peptide sequences their analogs were chemically synthesized and tested. Peptide LAPSLPGKPKPD showed the strongest ACE inhibitory activity, with IC₅₀ value of 1.97 μmol/L. Peptides with specific biological activity can be used in pharmaceutical, cosmetic or food industries. Because of their potential role as physiological modulators, as well as theirhigh safety profile, they can be used as natural pharmacological compounds or functional food ingredients. The development of biotechnological solutions to obtain peptides with desired biological activity is already in progress. Studies in this area are focused on using unconventional highly specific enzymes and more efficient methods developed to conduct food process technologies. Natural peptides have many advantages. They are mainly toxicologically safe, have wide spectra of therapeutic actions, exhibit less side effects compared to synthetic drugs and are more efficiently absorbed in the intestinal tract. The complexity of

  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. Effects of gastric inhibitory polypeptide, glucagon-like peptide-1 and glucagon-like peptide-1 receptor agonists on Bone Cell Metabolism

    DEFF Research Database (Denmark)

    Hansen, Morten S S; Tencerova, Michaela; Frølich, Jacob

    2018-01-01

    The relationship between gut and skeleton is increasingly recognised as part of the integrated physiology of the whole organism. The incretin hormones gastric inhibitory polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are secreted from the intestine in response to nutrient intake and exhibi......-clinical investigations, clinical trials are needed to clarify if similar effects are present and clinically relevant in humans. This article is protected by copyright. All rights reserved....

  9. 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.

  10. Oral Delivery of Probiotics Expressing Dendritic Cell-Targeting Peptide Fused with Porcine Epidemic Diarrhea Virus COE Antigen: A Promising Vaccine Strategy against PEDV.

    Science.gov (United States)

    Wang, Xiaona; Wang, Li; Huang, Xuewei; Ma, Sunting; Yu, Meiling; Shi, Wen; Qiao, Xinyuan; Tang, Lijie; Xu, Yigang; Li, Yijing

    2017-10-25

    Porcine epidemic diarrhea virus (PEDV), an enteric coronavirus, is the causative agent of porcine epidemic diarrhea (PED) that damages intestinal epithelial cells and results in severe diarrhea and dehydration in neonatal suckling pigs with up to 100% mortality. The oral vaccine route is reported as a promising approach for inducing protective immunity against PEDV invasion. Furthermore, dendritic cells (DCs), professional antigen-presenting cells, link humoral and cellular immune responses for homeostasis of the intestinal immune environment. In this study, in order to explore an efficient oral vaccine against PEDV infection, a mucosal DC-targeting oral vaccine was developed using Lactobacillus casei to deliver the DC-targeting peptide (DCpep) fused with the PEDV core neutralizing epitope (COE) antigen. This probiotic vaccine could efficiently elicit secretory immunoglobulin A (SIgA)-based mucosal and immunoglobulin G (IgG)-based humoral immune responses via oral vaccination in vivo. Significant differences ( p targeting peptide fused with PEDV COE antigen. This mucosal DC-targeting oral vaccine delivery effectively enhances vaccine antigen delivery efficiency, providing a useful strategy to induce efficient immune responses against PEDV infection.

  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. Binding of cholesterol and inhibitory peptide derivatives with the fusogenic hydrophobic sequence of F-glycoprotein of HVJ (Sendai virus): possible implication in the fusion reaction

    International Nuclear Information System (INIS)

    Asano, K.; Asano, A.

    1988-01-01

    Specificity of the binding of sterols and related compounds with purified F-protein (fusion protein) of the HVJ (Sendai virus) was studied by binding competition with [ 3 H] cholesterol. Requirement for cholesterol or the A/B ring trans structure and nonrequirement for the 3-hydroxyl group were found in this binding. Binding of 125 I-labeled Z-Phe-Tyr, an inhibitory peptide of viral membrane-cell membrane fusion, was studied by using purified proteins and virions. F-Protein and virions showed a specific binding with the peptide, whereas the result was negative with hemagglutinin and neuraminidase protein. Thermolysin-truncated F-protein (an F-protein derivative deprived of a 2.5-kDa fragment from the N-terminal of the F 1 subunit and without fusogenic activity) exhibited a considerably diminished binding ability both to cholesterol and to inhibitory peptides. Therefore, the N-terminal hydrophobic sequence that was previously assigned as fusogenic seems to be the binding site of these molecules. In support of this, the binding of cholesterol with F-protein was inhibited by Z-Phe-Tyr and other fusion inhibitory peptides, whereas it was not affected with non-fusion-inhibitory Z-Gly-Phe. These results are discussed in relation to the notion that the binding of the N-terminal portion of the F 1 subunit of F-protein with cholesterol in the target cell membranes facilitiates the fusion reaction

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Dual Actions of Mammalian and Piscine Gonadotropin-Inhibitory Hormones, RFamide-Related Peptides and LPXRFamide Peptides, in the Hypothalamic–Pituitary–Gonadal Axis

    Directory of Open Access Journals (Sweden)

    Takayoshi Ubuka

    2018-01-01

    Full Text Available Gonadotropin-inhibitory hormone (GnIH is a hypothalamic neuropeptide that decreases gonadotropin synthesis and release by directly acting on the gonadotrope or by decreasing the activity of gonadotropin-releasing hormone (GnRH neurons. GnIH is also called RFamide-related peptide in mammals or LPXRFamide peptide in fishes due to its characteristic C-terminal structure. The primary receptor for GnIH is GPR147 that inhibits cAMP production in target cells. Although most of the studies in mammals, birds, and fish have shown the inhibitory action of GnIH in the hypothalamic–pituitary–gonadal (HPG axis, several in vivo studies in mammals and many in vivo and in vitro studies in fish have shown its stimulatory action. In mouse, although the firing rate of the majority of GnRH neurons is decreased, a small population of GnRH neurons is stimulated by GnIH. In hamsters, GnIH inhibits luteinizing hormone (LH release in the breeding season when their endogenous LH level is high but stimulates LH release in non-breeding season when their LH level is basal. Besides different effects of GnIH on the HPG axis depending on the reproductive stages in fish, higher concentration or longer duration of GnIH administration can stimulate their HPG axis. These results suggest that GnIH action in the HPG axis is modulated by sex-steroid concentration, the action of neuroestrogen synthesized by the activity of aromatase stimulated by GnIH, estrogen membrane receptor, heteromerization and internalization of GnIH, GnRH, and estrogen membrane receptors. The inhibitory and stimulatory action of GnIH in the HPG axis may have a physiological role to maintain reproductive homeostasis according to developmental and reproductive stages.

  15. Small lytic peptides escape the inhibitory effect of heparan sulfate on the surface of cancer cells

    Science.gov (United States)

    2011-01-01

    Background Several naturally occurring cationic antimicrobial peptides (CAPs), including bovine lactoferricin (LfcinB), display promising anticancer activities. These peptides are unaffected by multidrug resistance mechanisms and have been shown to induce a protective immune response against solid tumors, thus making them interesting candidates for developing novel lead structures for anticancer treatment. Recently, we showed that the anticancer activity by LfcinB was inhibited by the presence of heparan sulfate (HS) on the surface of tumor cells. Based on extensive structure-activity relationship studies performed on LfcinB, shorter and more potent peptides have been constructed. In the present study, we have investigated the anticancer activity of three chemically modified 9-mer peptides and the influence of HS and chondroitin sulfate (CS) on their cytotoxic activity. Methods Various cell lines and red blood cells were used to investigate the anticancer activity and selectivity of the peptides. The cytotoxic effect of the peptides against the different cell lines was measured by use of a colorimetric MTT viability assay. The influence of HS and CS on their cytotoxic activity was evaluated by using HS/CS expressing and HS/CS deficient cell lines. The ability of soluble HS and CS to inhibit the cytotoxic activity of the peptides and the peptides' affinity for HS and CS were also investigated. Results The 9-mer peptides displayed selective anticancer activity. Cells expressing HS/CS were equally or more susceptible to the peptides than cells not expressing HS/CS. The peptides displayed a higher affinity for HS compared to CS, and exogenously added HS inhibited the cytotoxic effect of the peptides. Conclusions In contrast to the previously reported inhibitory effect of HS on LfcinB, the present study shows that the cytotoxic activity of small lytic peptides was increased or not affected by cell surface HS. PMID:21453492

  16. Small lytic peptides escape the inhibitory effect of heparan sulfate on the surface of cancer cells

    Directory of Open Access Journals (Sweden)

    Lindin Inger

    2011-03-01

    Full Text Available Abstract Background Several naturally occurring cationic antimicrobial peptides (CAPs, including bovine lactoferricin (LfcinB, display promising anticancer activities. These peptides are unaffected by multidrug resistance mechanisms and have been shown to induce a protective immune response against solid tumors, thus making them interesting candidates for developing novel lead structures for anticancer treatment. Recently, we showed that the anticancer activity by LfcinB was inhibited by the presence of heparan sulfate (HS on the surface of tumor cells. Based on extensive structure-activity relationship studies performed on LfcinB, shorter and more potent peptides have been constructed. In the present study, we have investigated the anticancer activity of three chemically modified 9-mer peptides and the influence of HS and chondroitin sulfate (CS on their cytotoxic activity. Methods Various cell lines and red blood cells were used to investigate the anticancer activity and selectivity of the peptides. The cytotoxic effect of the peptides against the different cell lines was measured by use of a colorimetric MTT viability assay. The influence of HS and CS on their cytotoxic activity was evaluated by using HS/CS expressing and HS/CS deficient cell lines. The ability of soluble HS and CS to inhibit the cytotoxic activity of the peptides and the peptides' affinity for HS and CS were also investigated. Results The 9-mer peptides displayed selective anticancer activity. Cells expressing HS/CS were equally or more susceptible to the peptides than cells not expressing HS/CS. The peptides displayed a higher affinity for HS compared to CS, and exogenously added HS inhibited the cytotoxic effect of the peptides. Conclusions In contrast to the previously reported inhibitory effect of HS on LfcinB, the present study shows that the cytotoxic activity of small lytic peptides was increased or not affected by cell surface HS.

  17. Purification, identification and molecular mechanism of two dipeptidyl peptidase IV (DPP-IV) inhibitory peptides from Antarctic krill (Euphausia superba) protein hydrolysate.

    Science.gov (United States)

    Ji, Wei; Zhang, Chaohua; Ji, Hongwu

    2017-10-01

    Dipeptidyl peptidase IV (DPP-IV) played an important role in blood glucose regulation. Inhibition of DPP-IV may improve glycemic control in diabetics by preventing the rapid breakdown of incretin hormones and prolonging their physiological action. In this study, Antarctic krill (Euphausia superba) protein was hydrolyzed using animal proteolytic enzymes. The hydrolysate was purified sequentially by ultrafiltration, gel filtration chromatography and reversed phase high-performance liquid chromatography (RP-HPLC). DPP-IV inhibitory activity of the fractions achieved from Antarctic krill protein was determined by DPP-IV screening reagent kit. Two purified peptides were identified by Xevo G2-XS QTof mass spectrometer (QTOF-MS). One peptide purified was Ala-Pro (AP) with IC 50 values of 0.0530mg/mL, the other Ile-Pro-Ala (IPA) with IC 50 values of 0.0370mg/mL. They both exhibited strong DPP-IV inhibitory activity. The molecular docking analysis revealed that DPP-IV inhibition by AP and IPA was mainly due to formation of a strong interaction surface force with the 91-96 and 101-105 amino acids of the DPP-IV. Our results suggested that the protein hydrolysate from Antarctic krill can be considered as a promising natural source of DPP-IV inhibitory peptides in the management of diabetes. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Therapeutic peptides for cancer therapy. Part II - cell cycle inhibitory peptides and apoptosis-inducing peptides.

    Science.gov (United States)

    Raucher, Drazen; Moktan, Shama; Massodi, Iqbal; Bidwell, Gene L

    2009-10-01

    Therapeutic peptides have great potential as anticancer agents owing to their ease of rational design and target specificity. However, their utility in vivo is limited by low stability and poor tumor penetration. The authors review the development of peptide inhibitors with potential for cancer therapy. Peptides that arrest the cell cycle by mimicking CDK inhibitors or induce apoptosis directly are discussed. The authors searched Medline for articles concerning the development of therapeutic peptides and their delivery. Inhibition of cancer cell proliferation directly using peptides that arrest the cell cycle or induce apoptosis is a promising strategy. Peptides can be designed that interact very specifically with cyclins and/or cyclin-dependent kinases and with members of apoptotic cascades. Use of these peptides is not limited by their design, as a rational approach to peptide design is much less challenging than the design of small molecule inhibitors of specific protein-protein interactions. However, the limitations of peptide therapy lie in the poor pharmacokinetic properties of these large, often charged molecules. Therefore, overcoming the drug delivery hurdles could open the door for effective peptide therapy, thus making an entirely new class of molecules useful as anticancer drugs.

  19. Identification and functional analysis of a novel bradykinin inhibitory peptide in the venoms of New World Crotalinae pit vipers

    International Nuclear Information System (INIS)

    James Graham, Robert Leslie; Graham, Ciaren; McClean, Stephen; Chen, Tianbao; O'Rourke, Martin; Hirst, David; Theakston, David; Shaw, Chris

    2005-01-01

    A novel undecapeptide has been isolated and structurally characterized from the venoms of three species of New World pit vipers from the subfamily, Crotalinae. These include the Mexican moccasin (Agkistrodon bilineatus), the prairie rattlesnake (Crotalus viridis viridis), and the South American bushmaster (Lachesis muta). The peptide was purified from all three venoms using a combination of gel permeation chromatography and reverse-phase HPLC. Automated Edman degradation sequencing and MALDI-TOF mass spectrometry established its peptide primary structure as: Thr-Pro-Pro-Ala-Gly-Pro-Asp-Val-Gly-Pro-Arg-OH, with a non-protonated molecular mass of 1063.18 Da. A synthetic replicate of the peptide was found to be an antagonist of bradykinin action at the rat vascular B2 receptor. This is the first bradykinin inhibitory peptide isolated from snake venom. Database searching revealed the peptide to be highly structurally related (10/11 residues) with a domain residing between the bradykinin-potentiating peptide and C-type natriuretic peptide domains of a recently cloned precursor from tropical rattlesnake (Crotalus durissus terrificus) venom gland. BIP thus represents a novel biological entity from snake venom

  20. 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...

  1. Virus-cell fusion inhibitory activity of novel analogue peptides based on the HP (2-20) derived from N-terminus of Helicobacter pylori Ribosomal Protein L1.

    Science.gov (United States)

    Woo, Eun-Rhan; Lee, Dong Gun; Chang, Young-Su; Park, Yoonkyung; Hahm, Kyung-Soo

    2002-12-01

    HP (2-20) (AKKVFKRLEKLFSKIQNDK) is the antibacterial sequence derived from N-terminus of Helicobacter pylori Ribosomal Protein L1 (RPL1). It has a broad-spectrum microbicidal activity in vitro that is thought to be related to the membrane-disruptive properties of the peptide. Based on the putative membrane-targeted mode of action, we postulated that HP (2-20) might be possessed virus-cell fusion inhibitory activity. To develop the novel virus-cell fusion inhibitory peptides, several analogues with amino acid substitution were designed to increase or decrease only net hydrophobic region. In particular, substitution of Gln and Asp for hydrophobic amino acid, Trp at position 17 and 19 of HP (2-20) (Anal 3) caused a dramatic increase in virus-cell fusion inhibitory activity without hemolytic effect.

  2. Antihypertensive properties of lactoferricin B-derived peptides.

    Science.gov (United States)

    Ruiz-Giménez, Pedro; Ibáñez, Aida; Salom, Juan B; Marcos, Jose F; López-Díez, Jose Javier; Vallés, Salvador; Torregrosa, Germán; Alborch, Enrique; Manzanares, Paloma

    2010-06-09

    A set of eight lactoferricin B (LfcinB)-derived peptides was examined for inhibitory effects on angiotensin I-converting enzyme (ACE) activity and ACE-dependent vasoconstriction, and their hypotensive effect in spontaneously hypertensive rats (SHR). Peptides were derived from different elongations both at the C-terminal and N-terminal ends of the representative peptide LfcinB(20-25), which is known as the LfcinB antimicrobial core. All of the eight LfcinB-derived peptides showed in vitro inhibitory effects on ACE activity with different IC(50) values. Moreover, seven of them showed ex vivo inhibitory effects on ACE-dependent vasoconstriction. No clear correlation between in vitro and ex vivo inhibitory effects was found. Only LfcinB(20-25) and one of its fragments, F1, generated after a simulated gastrointestinal digestion, showed significant antihypertensive effects in SHR after oral administration. Remarkably, F1 did not show any effect on ACE-dependent vasoconstriction in contrast to the inhibitory effect showed by LfcinB(20-25). In conclusion, two LfcinB-derived peptides lower blood pressure and exhibit potential as orally effective antihypertensive compounds, yet a complete elucidation of the mechanism(s) involved deserves further ongoing research.

  3. Discordance between in silico & in vitro analyses of ACE inhibitory & antioxidative peptides from mixed milk tryptic whey protein hydrolysate.

    Science.gov (United States)

    Chatterjee, Alok; Kanawjia, S K; Khetra, Yogesh; Saini, Prerna

    2015-09-01

    ACE inhibitory and antioxidative peptides identified by LCMS/MS, from mixed milk (Bubalus bubalis and Bos taurus) tryptic whey protein hydrolysate, were compared with the in silico predictions. α la and ß lg sequences, both from Bubalus bubalis and Bos taurus, were used for in silico study. SWISS-PROT and BIOPEP protein libraries were accessed for prediction of peptide generation. Study observed gaps in the prediction versus actual results, which remain unaddressed in the literature. Many peptides obtained in vitro, were not reflected in in silico predictions. Differences in identified peptides in separate libraries were observed too. In in silico prediction, peptides with known biological activities were also not reflected. Predictions, towards generation of bioactive peptides, based upon in silico release of proteins and amino acid sequences from different sources and thereupon validation in relation to actual results has often been reported in research literature. Given that computer aided simulation for prediction purposes is an effective research direction, regular updating of protein libraries and an effectual integration, for more precise results, is critical. The gaps addressed between these two techniques of research, have not found any address in literature. Inclusion of more flexibility with the variables, within the tools being used for prediction, and a hierarchy based database with search options for various peptides, will further enhance the scope and strength of research.

  4. Analysis of whey protein hydrolysates: peptide profile and ACE inhibitory activity

    Directory of Open Access Journals (Sweden)

    Marialice Pinto Coelho Silvestre

    2012-12-01

    Full Text Available The aim of this study was to prepare enzymatic hydrolysates from whey protein concentrate with a nutritionally adequate peptide profile and the ability to inhibit angiotensin-converting enzyme (ACE activity. The effects of the type of enzyme used (pancreatin or papain, the enzyme:substrate ratio (E:S ratio=0.5:100, 1:100, 2:100 and 3:100 and the use of ultrafiltration (UF were investigated. The fractionation of peptides was performed by size-exclusion-HPLC, and the quantification of the components of the chromatographic fractions was carried out by a rapid Corrected Fraction Area method. The ACE inhibitory activity (ACE-IA was determined by Reverse Phase-HPLC. All parameters tested affected both the peptide profile and the ACE-IA. The best peptide profile was achieved for the hydrolysates obtained with papain, whereas pancreatin was more advantageous in terms of ACE-IA. The beneficial effect of using a lower E:S ratio on the peptide profile and ACE-IA was observed for both enzymes depending on the conditions used to prepare the hydrolysates. The beneficial effect of not using UF on the peptide profile was observed in some cases for pancreatin and papain. However, the absence of UF yielded greater ACE-IA only when using papain.O objetivo deste estudo foi preparar hidrolisados enzimáticos do concentrado proteico do soro de leite com perfil peptídico nutricionalmente adequado e com capacidade para inibir a atividade da enzima conversora da angiotensina (ECA. Os efeitos do tipo de enzima usado (pancreatina ou papaína, da relação enzima:substrato (E:S=0,5:100, 1:100, 2:100 e 3:100 e do uso da ultrafiltração (UF foram investigados. O fracionamento dos peptídeos foi feito por CLAE de exclusão molecular e a quantificação dos componentes das frações cromatográficas foi realizada pelo método da Área Corrigida da Fração. A atividade inibitória da ECA (AI-ECA foi determinada por CLAE de fase reversa. Todos os parâmetros testados afetaram

  5. Role of Glucagon-Like Peptide-1 and Gastric Inhibitory Peptide in Anorexia Induction Following Oral Exposure to the Trichothecene Mycotoxin Deoxynivalenol (Vomitoxin).

    Science.gov (United States)

    Jia, Hui; Wu, Wen-Da; Lu, Xi; Zhang, Jie; He, Cheng-Hua; Zhang, Hai-Bin

    2017-09-01

    Deoxynivalenol (DON), which is a Type B trichothecene mycotoxin produced by Fusarium, frequently contaminates cereal staples, such as wheat, barley and corn. DON threatens animal and human health by suppressing food intake and impairing growth. While anorexia induction in mice exposed to DON has been linked to the elevation of the satiety hormones cholecystokinin and peptide YY3-36 in plasma, the effects of DON on the release of other satiety hormones, such as glucagon-like peptide-1 (GLP-1) and gastric inhibitory peptide (GIP), have not been established. The purpose of this study was to determine the roles of GLP-1 and GIP in DON-induced anorexia. In a nocturnal mouse food consumption model, the elevation of plasma GLP-1 and GIP concentrations markedly corresponded to anorexia induction by DON. Pretreatment with the GLP-1 receptor antagonist Exendin9-39 induced a dose-dependent attenuation of both GLP-1- and DON-induced anorexia. In contrast, the GIP receptor antagonist Pro3GIP induced a dose-dependent attenuation of both GIP- and DON-induced anorexia. Taken together, these results suggest that GLP-1 and GIP play instrumental roles in anorexia induction following oral exposure to DON, and the effect of GLP-1 is more potent and long-acting than that of GIP. © The Author 2017. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  6. Characterization and identification of novel antidiabetic and anti-obesity peptides from camel milk protein hydrolysates.

    Science.gov (United States)

    Mudgil, Priti; Kamal, Hina; Yuen, Gan Chee; Maqsood, Sajid

    2018-09-01

    In-vitro inhibitory properties of peptides released from camel milk proteins against dipeptidyl peptidase-IV (DPP-IV), porcine pancreatic α-amylase (PPA), and porcine pancreatic lipase (PPL) were studied. Results revealed that upon hydrolysis by different enzymes, camel milk proteins displayed dramatic increase in inhibition of DPP-IV and PPL, but slight improvement in PPA inhibition was noticed. Peptide sequencing revealed a total of 20 and 3 peptides for A9 and B9 hydrolysates respectively, obtained the score of 0.8 or more on peptide ranker and were categorized as potential DPP-IV inhibitory peptides. KDLWDDFKGL in A9 and MPSKPPLL in B9 were identified as most potent PPA inhibitory peptide. For PPL inhibition only 7 and 2 peptides qualified as PPL inhibitory peptides from hydrolysates A9 and B9, respectively. The present study report for the first time PPA and PPL inhibitory and only second for DPP-IV inhibitory potential of protein hydrolysates from camel milk. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Egg ovotransferrin-derived ACE inhibitory peptide IRW increases ACE2 but decreases proinflammatory genes expression in mesenteric artery of spontaneously hypertensive rats.

    Science.gov (United States)

    Majumder, Kaustav; Liang, Guanxiang; Chen, Yanhong; Guan, LeLuo; Davidge, Sandra T; Wu, Jianping

    2015-09-01

    Egg ovotransferrin-derived angiotensin converting enzyme (ACE) inhibitory peptide IRW was previously shown to reduce blood pressure in spontaneously hypertensive rats through reduced vascular inflammation and increased nitric oxide-mediated vasorelaxation. The main objective of the present study was to investigate the molecular mechanism of this peptide through transcriptome analysis by RNAseq technique. Total RNA was extracted from kidney and mesenteric arteries; the RNAseq libraries (from untreated and IRW-treated groups) were constructed and subjected to sequence using HiSeq 2000 system (Illumina) system. A total of 12 764 and 13 352 genes were detected in kidney and mesenteric arteries, respectively. The differentially expressed (DE) genes between untreated and IRW-treated groups were identified and the functional analysis through ingenuity pathway analysis revealed a greater role of DE genes identified from mesenteric arteries than that of kidney in modulating various cardiovascular functions. Subsequent qPCR analysis further confirmed that IRW significantly increased the expression of ACE-2, ABCB-1, IRF-8, and CDH-1 while significantly decreased the expression ICAM-1 and VCAM-1 in mesenteric arteries. Our research showed for the first time that ACE inhibitory peptide IRW could contribute to its antihypertensive activity through increased ACE2 and decreased proinflammatory genes expression. © 2015 The Authors. Molecular Nutrition & Food Research published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Synthetic peptide inhibitors of DNA replication in Staphylococcus aureus

    DEFF Research Database (Denmark)

    Løbner-Olesen, Anders; Kjelstrup, Susanne

    F counterselection was developed to directly select for compounds able to disrupt selected interactions. We have subsequently constructed a cyclic peptide library for intracellular synthesis of cyclic peptides using known technology. Several cyclic peptides were able to interfere with oligomerization of Dna......N (), DnaB and DnaX (). Three peptides identified as inhibitors of DnaN have been purified. Two of these peptides inhibited growth as well as DNA replication in S. aureus. The minimal inhibitory concentration (MIC) of the peptides was approximately 50 g/ml. Overexpression of DnaN reduced the inhibitory...

  9. The dipeptidyl peptidase 4 inhibitor vildagliptin does not accentuate glibenclamide-induced hypoglycemia but reduces glucose-induced glucagon-like peptide 1 and gastric inhibitory polypeptide secretion

    DEFF Research Database (Denmark)

    El-Ouaghlidi, Andrea; Rehring, Erika; Holst, Jens Juul

    2007-01-01

    BACKGROUND/AIMS: Inhibition of dipeptidyl peptidase 4 by vildagliptin enhances the concentrations of the active form of the incretin hormones glucagon-like peptide 1 (GLP-1) and gastric inhibitory polypeptide (GIP). The present study asked whether vildagliptin accentuates glibenclamide-induced hy...

  10. In Vivo Efficacy of Measles Virus Fusion Protein-Derived Peptides Is Modulated by the Properties of Self-Assembly and Membrane Residence

    Science.gov (United States)

    Figueira, T. N.; Palermo, L. M.; Veiga, A. S.; Huey, D.; Alabi, C. A.; Santos, N. C.; Welsch, J. C.; Mathieu, C.; Niewiesk, S.; Moscona, A.

    2016-01-01

    ABSTRACT Measles virus (MV) infection is undergoing resurgence and remains one of the leading causes of death among young children worldwide despite the availability of an effective measles vaccine. MV infects its target cells by coordinated action of the MV hemagglutinin (H) and fusion (F) envelope glycoproteins; upon receptor engagement by H, the prefusion F undergoes a structural transition, extending and inserting into the target cell membrane and then refolding into a postfusion structure that fuses the viral and cell membranes. By interfering with this structural transition of F, peptides derived from the heptad repeat (HR) regions of F can inhibit MV infection at the entry stage. In previous work, we have generated potent MV fusion inhibitors by dimerizing the F-derived peptides and conjugating them to cholesterol. We have shown that prophylactic intranasal administration of our lead fusion inhibitor efficiently protects from MV infection in vivo. We show here that peptides tagged with lipophilic moieties self-assemble into nanoparticles until they reach the target cells, where they are integrated into cell membranes. The self-assembly feature enhances biodistribution and the half-life of the peptides, while integration into the target cell membrane increases fusion inhibitor potency. These factors together modulate in vivo efficacy. The results suggest a new framework for developing effective fusion inhibitory peptides. IMPORTANCE Measles virus (MV) infection causes an acute illness that may be associated with infection of the central nervous system (CNS) and severe neurological disease. No specific treatment is available. We have shown that fusion-inhibitory peptides delivered intranasally provide effective prophylaxis against MV infection. We show here that specific biophysical properties regulate the in vivo efficacy of MV F-derived peptides. PMID:27733647

  11. Facilitating protein solubility by use of peptide extensions

    Science.gov (United States)

    Freimuth, Paul I; Zhang, Yian-Biao; Howitt, Jason

    2013-09-17

    Expression vectors for expression of a protein or polypeptide of interest as a fusion product composed of the protein or polypeptide of interest fused at one terminus to a solubility enhancing peptide extension are provided. Sequences encoding the peptide extensions are provided. The invention further comprises antibodies which bind specifically to one or more of the solubility enhancing peptide extensions.

  12. Mechanism of Cancer Growth Suppression of Alpha-Fetoprotein Derived Growth Inhibitory Peptides (GIP): Comparison of GIP-34 versus GIP-8 (AFPep). Updates and Prospects

    Energy Technology Data Exchange (ETDEWEB)

    Mizejewski, Gerald J. [Division of Translational Medicine, Wadsworth Center, New York State Department of Health, Empire State Plaza, Albany, NY 12201 (United States)

    2011-06-20

    The Alpha-fetoprotein (AFP) derived Growth Inhibitory Peptide (GIP) is a 34-amino acid segment of the full-length human AFP molecule that inhibits tumor growth and metastasis. The GIP-34 and its carboxy-terminal 8-mer segment, termed GIP-8, were found to be effective as anti-cancer therapeutic peptides against nine different human cancer types. Following the uptake of GIP-34 and GIP-8 into the cell cytoplasm, each follows slightly different signal transduction cascades en route to inhibitory pathways of tumor cell growth and proliferation. The parallel mechanisms of action of GIP-34 versus GIP-8 are demonstrated to involve interference of signaling transduction cascades that ultimately result in: (1) cell cycle S-phase/G2-phase arrest; (2) prevention of cyclin inhibitor degradation; (3) protection of p53 from inactivation by phosphorylation; and (4) blockage of K{sup +} ion channels opened by estradiol and epidermal growth factor (EGF). The overall mechanisms of action of both peptides are discussed in light of their differing modes of cell attachment and uptake fortified by RNA microarray analysis and electrophysiologic measurements of cell membrane conductance and resistance. As a chemotherapeutic adjunct, the GIPs could potentially aid in alleviating the negative side effects of: (1) tamoxifen resistance, uterine hyperplasia/cancer, and blood clotting; (2) Herceptin antibody resistance and cardiac (arrest) arrhythmias; and (3) doxorubicin's bystander cell toxicity.

  13. Peptides Interfering 3A Protein Dimerization Decrease FMDV Multiplication.

    Directory of Open Access Journals (Sweden)

    Mónica González-Magaldi

    Full Text Available Nonstructural protein 3A is involved in relevant functions in foot-and-mouth disease virus (FMDV replication. FMDV 3A can form homodimers and preservation of the two hydrophobic α-helices (α1 and α2 that stabilize the dimer interface is essential for virus replication. In this work, small peptides mimicking residues involved in the dimer interface were used to interfere with dimerization and thus gain insight on its biological function. The dimer interface peptides α1, α2 and that spanning the two hydrophobic α-helices, α12, impaired in vitro dimer formation of a peptide containing the two α-helices, this effect being higher with peptide α12. To assess the effect of dimer inhibition in cultured cells, the interfering peptides were N-terminally fused to a heptaarginine (R7 sequence to favor their intracellular translocation. Thus, when fused to R7, interference peptides (100 μM were able to inhibit dimerization of transiently expressed 3A, the higher inhibitions being found with peptides α1 and α12. The 3A dimerization impairment exerted by the peptides correlated with significant, specific reductions in the viral yield recovered from peptide-treated FMDV infected cells. In this case, α2 was the only peptide producing significant reductions at concentrations lower than 100 μM. Thus, dimer interface peptides constitute a tool to understand the structure-function relationship of this viral protein and point to 3A dimerization as a potential antiviral target.

  14. Low dose radiation enhancing inhibitory effect of tumor-associated antigen peptide extract on H-22 hepatocarcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Zuyue, Sun; Jingyi, Fu; Yong, Zhao [Transplantation Biology Research Division, State Key Laboratory of Biomembrane and Membrane Biotechnology, Inst. of Zoology, Chinese Academy of Sciences, Beijing (China); Jianxiang, Liu; Zhibo, Fu; Xiuyi, Li; Shuzheng, Liu; Shouliang, Gong

    2005-06-15

    Objective: To determine whether there is synergically inhibitory effect of low dose radiation (LDR) and tumor-associated antigen peptides (TAP) on tumor growth in vivo, which may provide experimental basis for potential clinical co-application of these two approaches to treat cancers. Methods: TAP extract (MW {<=}3x10{sup 6}) from tumor cell membrane was prepared with mild acid elution method , as reported. The mice were whole-bodily irradiated with 75 mGy X-rays 12 h before immunization with TAP extract. After immunization , the levels of CD3, CD69, TCR{alpha}{beta} cells and T cell subsets in the spleen were detected with FACS. The tumor growth rate was estimated, and the responses to Con A, the cytokine productions and CTL activities of splenocytes were also analyzed 7 d after immunization with TAP. Results: The present experimental results showed that the TAP extract significantly reduced the incidence of the transplanted tumor, delayed the average appearing time and decreased the growth speed of the tumor. The response of splenocytes from mice immunized with TAP extract to Con A increased significantly compared with that in the control group. Irradiation with 75 mGy X-rays 12 h before immunization further enhanced the inhibitory effect of TAP extract on tumor growth, and increased the percentage of CD8{sup +} splenocytes. Conclusion: These results suggest that whole-body irradiation with LDR exerts a synergic inhibitory effect with TAP on tumor growth in vivo, in which enhanced cellular immune responses may be involved. (authors)

  15. Acetone-Linked Peptides: A Convergent Approach for Peptide Macrocyclization and Labeling.

    Science.gov (United States)

    Assem, Naila; Ferreira, David J; Wolan, Dennis W; Dawson, Philip E

    2015-07-20

    Macrocyclization is a broadly applied approach for overcoming the intrinsically disordered nature of linear peptides. Herein, it is shown that dichloroacetone (DCA) enhances helical secondary structures when introduced between peptide nucleophiles, such as thiols, to yield an acetone-linked bridge (ACE). Aside from stabilizing helical structures, the ketone moiety embedded in the linker can be modified with diverse molecular tags by oxime ligation. Insights into the structure of the tether were obtained through co-crystallization of a constrained S-peptide in complex with RNAse S. The scope of the acetone-linked peptides was further explored through the generation of N-terminus to side chain macrocycles and a new approach for generating fused macrocycles (bicycles). Together, these studies suggest that acetone linking is generally applicable to peptide macrocycles with a specific utility in the synthesis of stabilized helices that incorporate functional tags. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. CONSTRUCTION, EXPRESSION AND PURIFICATION OF RECOMBINANT PRE-MATURE PEPTIDE OF PLANTARICIN F FROM Lactobacillus plantarum S34 IN Escherichia coli

    Directory of Open Access Journals (Sweden)

    Kusdianawati Kusdianawati

    2015-09-01

    Full Text Available Plantaricin is one of bacteriocins that have the potential to be used as food preservative. Plantaricin is safe for human consumption because it can be easily degraded by proteolytic enzymes. The objective of this study was to express and purify recombinant pre-mature peptide of plantaricin F from Lactobacillus plantarum S34 in Escherichia coli. Plantaricin gene-specific primer was used to obtain pln F structural gene amplicon from L. plantarum S34. This amplicon was cloned in pET32a vector and expressed in E. coli BL21 (DE3 pLysS. Pre-mature plantaricin F peptide was expressed as Histagged-fusion protein and separated by Co2+-chelating affinity chromatography. L. plantarum S34-derived pre-mature plantaricin F peptide fused with thioredoxin-(His6tag had successfully been expressed in E. coli BL21 (DE3 pLysS using pET32a as an expression vector. The fused recombinant pln F as pre-mature state expressed had a molecular mass of +24 kDa, meanwhile the fused recombinant that contained only the leader peptide of pln F appeared as +20 kDa based on SDS-PAGE separations. The optimal production of fused recombinant pln F as soluble fraction was obtained when culture condition was added with 0.5 mM of IPTG and incubated at 22°C for 5 hours (OD~1. Furthermore, the expression of fused recombinant pln F as its pre-mature peptide pointed out that the pln F’s leader peptide could be proteolytically cleaved by a system in heterologous cells. Overall, heterologous pln F production as pre-mature peptide fused with thioredoxin-(His6tag had been well established. From this research, we expect plantaricin F can be expressed and purified in E. coli.

  17. Optimization of Goat Milk with ACE Inhibitory Peptides Fermented by Lactobacillus bulgaricus LB6 Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Guowei Shu

    2017-11-01

    Full Text Available In the present study, the incubation conditions of goat milk fermented by Lactobacillus bulgaricus LB6 were optimized to increase the angiotensin converting enzyme (ACE, EC 3.4.15.1 inhibitory activity by Box–Behnken design of response surface methodology. Incubation temperature, whey powder, and calcium lactate had significant effects on ACE inhibition rate and viable counts of LB6 during incubation. The results showed that optimal conditions of fermentation were found to be 37.05 °C, 0.8% (w/w whey powder and 0.50% (w/w calcium lactate. ACE inhibition rate increased significantly from 71.04 ± 0.37% to 83.31 ± 0.45% and the viable counts of Lactobacillus bulgaricus LB6 reached to 8.03 × 107 cfu·mL−1 under the optimal conditions, which approached the predicted values 83.25% and 8.04 × 107 cfu·mL−1. The optimal fermentation conditions can be a good reference for preparing ACE inhibitory peptides from goat milk.

  18. Optimization of Goat Milk with ACE Inhibitory Peptides Fermented by Lactobacillus bulgaricus LB6 Using Response Surface Methodology.

    Science.gov (United States)

    Shu, Guowei; Shi, Xiaoyu; Chen, He; Ji, Zhe; Meng, Jiangpeng

    2017-11-21

    In the present study, the incubation conditions of goat milk fermented by Lactobacillus bulgaricus LB6 were optimized to increase the angiotensin converting enzyme (ACE, EC 3.4.15.1) inhibitory activity by Box-Behnken design of response surface methodology. Incubation temperature, whey powder, and calcium lactate had significant effects on ACE inhibition rate and viable counts of LB6 during incubation. The results showed that optimal conditions of fermentation were found to be 37.05 °C, 0.8% ( w / w ) whey powder and 0.50% ( w / w ) calcium lactate. ACE inhibition rate increased significantly from 71.04 ± 0.37% to 83.31 ± 0.45% and the viable counts of Lactobacillus bulgaricus LB6 reached to 8.03 × 10⁷ cfu·mL -1 under the optimal conditions, which approached the predicted values 83.25% and 8.04 × 10⁷ cfu·mL -1 . The optimal fermentation conditions can be a good reference for preparing ACE inhibitory peptides from goat milk.

  19. One-week glucose control via zero-order release kinetics from an injectable depot of glucagon-like peptide-1 fused to a thermosensitive biopolymer.

    Science.gov (United States)

    Luginbuhl, Kelli M; Schaal, Jeffrey L; Umstead, Bret; Mastria, Eric M; Li, Xinghai; Banskota, Samagya; Arnold, Susan; Feinglos, Mark; D'Alessio, David; Chilkoti, Ashutosh

    2017-01-01

    Stimulation of the glucagon-like peptide-1 (GLP1) receptor is a useful treatment strategy for type 2 diabetes because of pleiotropic effects, including the regulation of islet hormones and the induction of satiety. However, the native ligand for the GLP1 receptor has a short half-live owing to enzymatic inactivation and rapid clearance. Here, we show that a subcutaneous depot formed after a single injection of GLP1 recombinantly fused to a thermosensitive elastin-like polypeptide results in zero-order release kinetics and circulation times of up to 10 days in mice and 17 days in monkeys. The optimized pharmacokinetics leads to 10 days of glycemic control in three different mouse models of diabetes, as well as to the reduction of glycosylated hemoglobin levels and weight gain in ob/ob mice treated once weekly for 8 weeks. Our results suggest that the optimized GLP1 formulation could enhance therapeutic outcomes by eliminating peak-and-valley pharmacokinetics and improving overall safety and tolerability. The design principles that we established should be broadly applicable for improving the pharmacological performance of other peptide and protein therapeutics.

  20. Hyperglycemia acutely lowers the postprandial excursions of glucagon-like Peptide-1 and gastric inhibitory polypeptide in humans

    DEFF Research Database (Denmark)

    Vollmer, Kirsten; Gardiwal, Husai; Menge, Bjoern A

    2009-01-01

    INTRODUCTION: Impaired secretion of glucagon-like peptide 1 (GLP-1) has been suggested to contribute to the deficient incretin effect in patients with type 2 diabetes. It is unclear whether this is a primary defect or a consequence of the hyperglycemia in type 2 diabetes. We examined whether acute...... hyperglycemia reduces the postprandial excursions of gastric inhibitory polypeptide (GIP) and GLP-1, and if so, whether this can be attributed to changes in gastric emptying. PATIENTS AND METHODS: Fifteen nondiabetic individuals participated in a euglycemic clamp and a hyperglycemic clamp experiment, carried...... the hyperglycemic clamp experiments and 83 +/- 3 mg/dl during the euglycemia (P hyperglycemia, but meal ingestion led to a decline in glucose requirements in both experiments (P

  1. Large structural modification with conserved conformation: analysis of delta(3)-fused aryl prolines in model beta-turns.

    Science.gov (United States)

    Jeannotte, Guillaume; Lubell, William D

    2004-11-10

    For the first time, the influence of a fused Delta3-arylproline on peptide conformation has been studied by the synthesis and comparison of the conformations of peptides containing proline and pyrrolo-proline, 3 (PyPro). Pyrrolo-proline was demonstrated to be a conservative replacement for Pro in model beta-turns, 4 and 5, as shown by their similar DMSO titration curves, cis/trans-isomer populations, and NOESY spectral data. Pyrrolo-proline may thus be used for studying the structure activity relationships of Pro-containing peptides with minimal modification of secondary structures.

  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. Cathepsin-Mediated Cleavage of Peptides from Peptide Amphiphiles Leads to Enhanced Intracellular Peptide Accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Acar, Handan [Institute; Department; Samaeekia, Ravand [Institute; Department; Schnorenberg, Mathew R. [Institute; Department; Medical; Sasmal, Dibyendu K. [Institute; Huang, Jun [Institute; Tirrell, Matthew V. [Institute; Institute; LaBelle, James L. [Department

    2017-08-24

    Peptides synthesized in the likeness of their native interaction domain(s) are natural choices to target protein protein interactions (PPIs) due to their fidelity of orthostatic contact points between binding partners. Despite therapeutic promise, intracellular delivery of biofunctional peptides at concentrations necessary for efficacy remains a formidable challenge. Peptide amphiphiles (PAs) provide a facile method of intracellular delivery and stabilization of bioactive peptides. PAs consisting of biofunctional peptide headgroups linked to hydrophobic alkyl lipid-like tails prevent peptide hydrolysis and proteolysis in circulation, and PA monomers are internalized via endocytosis. However, endocytotic sequestration and steric hindrance from the lipid tail are two major mechanisms that limit PA efficacy to target intracellular PPIs. To address these problems, we have constructed a PA platform consisting of cathepsin-B cleavable PAs in which a selective p53-based inhibitory peptide is cleaved from its lipid tail within endosomes, allowing for intracellular peptide accumulation and extracellular recycling of the lipid moiety. We monitor for cleavage and follow individual PA components in real time using a resonance energy transfer (FRET)-based tracking system. Using this platform, components in real time using a Forster we provide a better understanding and quantification of cellular internalization, trafficking, and endosomal cleavage of PAs and of the ultimate fates of each component.

  4. The effect of a beta-lactamase inhibitor peptide on bacterial membrane structure and integrity: a comparative study.

    Science.gov (United States)

    Alaybeyoglu, Begum; Uluocak, Bilge Gedik; Akbulut, Berna Sariyar; Ozkirimli, Elif

    2017-05-01

    Co-administration of beta-lactam antibiotics and beta-lactamase inhibitors has been a favored treatment strategy against beta-lactamase-mediated bacterial antibiotic resistance, but the emergence of beta-lactamases resistant to current inhibitors necessitates the discovery of novel non-beta-lactam inhibitors. Peptides derived from the Ala46-Tyr51 region of the beta-lactamase inhibitor protein are considered as potent inhibitors of beta-lactamase; unfortunately, peptide delivery into the cell limits their potential. The properties of cell-penetrating peptides could guide the design of beta-lactamase inhibitory peptides. Here, our goal is to modify the peptide with the sequence RRGHYY that possesses beta-lactamase inhibitory activity under in vitro conditions. Inspired by the work on the cell-penetrating peptide pVEC, our approach involved the addition of the N-terminal hydrophobic residues, LLIIL, from pVEC to the inhibitor peptide to build a chimera. These residues have been reported to be critical in the uptake of pVEC. We tested the potential of RRGHYY and its chimeric derivative as a beta-lactamase inhibitory peptide on Escherichia coli cells and compared the results with the action of the antimicrobial peptide melittin, the beta-lactam antibiotic ampicillin, and the beta-lactamase inhibitor potassium clavulanate to get mechanistic details on their action. Our results show that the addition of LLIIL to the N-terminus of the beta-lactamase inhibitory peptide RRGHYY increases its membrane permeabilizing potential. Interestingly, the addition of this short stretch of hydrophobic residues also modified the inhibitory peptide such that it acquired antimicrobial property. We propose that addition of the hydrophobic LLIIL residues to the peptide N-terminus offers a promising strategy to design novel antimicrobial peptides in the battle against antibiotic resistance. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd. Copyright © 2017 European

  5. Effect of a Fusion Peptide by Covalent Conjugation of a Mitochondrial Cell-Penetrating Peptide and a Glutathione Analog Peptide

    Directory of Open Access Journals (Sweden)

    Carmine Pasquale Cerrato

    2017-06-01

    Full Text Available Previously, we designed and synthesized a library of mitochondrial antioxidative cell-penetrating peptides (mtCPPs superior to the parent peptide, SS31, to protect mitochondria from oxidative damage. A library of antioxidative glutathione analogs called glutathione peptides (UPFs, exceptional in hydroxyl radical elimination compared with glutathione, were also designed and synthesized. Here, a follow-up study is described, investigating the effects of the most promising members from both libraries on reactive oxidative species scavenging ability. None of the peptides influenced cell viability at the concentrations used. Fluorescence microscopy studies showed that the fluorescein-mtCPP1-UPF25 (mtgCPP internalized into cells, and spectrofluorometric analysis determined the presence and extent of peptide into different cell compartments. mtgCPP has superior antioxidative activity compared with mtCPP1 and UPF25 against H2O2 insult, preventing ROS formation by 2- and 3-fold, respectively. Moreover, we neither observed effects on mitochondrial membrane potential nor production of ATP. These data indicate that mtgCPP is targeting mitochondria, protecting them from oxidative damage, while also being present in the cytosol. Our hypothesis is based on a synergistic effect resulting from the fused peptide. The mitochondrial peptide segment is targeting mitochondria, whereas the glutathione analog peptide segment is active in the cytosol, resulting in increased scavenging ability.

  6. The order of expression is a key factor in the production of active transglutaminase in Escherichia coli by co-expression with its pro-peptide

    Directory of Open Access Journals (Sweden)

    Liu Song

    2011-12-01

    Full Text Available Abstract Background Streptomyces transglutaminase (TGase is naturally synthesized as zymogen (pro-TGase, which is then processed to produce active enzyme by the removal of its N-terminal pro-peptide. This pro-peptide is found to be essential for overexpression of soluble TGase in E. coli. However, expression of pro-TGase by E. coli requires protease-mediated activation in vitro. In this study, we developed a novel co- expression method for the direct production of active TGase in E. coli. Results A TGase from S. hygroscopicus was expressed in E. coli only after fusing with the pelB signal peptide, but fusion with the signal peptide induced insoluble enzyme. Therefore, alternative protocol was designed by co-expressing the TGase and its pro-peptide as independent polypeptides under a single T7 promoter using vector pET-22b(+. Although the pro-peptide was co-expressed, the TGase fused without the signal peptide was undetectable in both soluble and insoluble fractions of the recombinant cells. Similarly, when both genes were expressed in the order of the TGase and the pro-peptide, the solubility of TGase fused with the signal peptide was not improved by the co-expression with its pro-peptide. Interestingly, active TGase was only produced by the cells in which the pro-peptide and the TGase were fused with the signal peptide and sequentially expressed. The purified recombinant and native TGase shared the similar catalytic properties. Conclusions Our results indicated that the pro-peptide can assist correct folding of the TGase inter-molecularly in E. coli, and expression of pro-peptide prior to that of TGase was essential for the production of active TGase. The co-expression strategy based on optimizing the order of gene expression could be useful for the expression of other functional proteins that are synthesized as a precursor.

  7. Suppression of a Natural Killer Cell Response by Simian Immunodeficiency Virus Peptides.

    Directory of Open Access Journals (Sweden)

    Jamie L Schafer

    2015-09-01

    Full Text Available Natural killer (NK cell responses in primates are regulated in part through interactions between two highly polymorphic molecules, the killer-cell immunoglobulin-like receptors (KIRs on NK cells and their major histocompatibility complex (MHC class I ligands on target cells. We previously reported that the binding of a common MHC class I molecule in the rhesus macaque, Mamu-A1*002, to the inhibitory receptor Mamu-KIR3DL05 is stabilized by certain simian immunodeficiency virus (SIV peptides, but not by others. Here we investigated the functional implications of these interactions by testing SIV peptides bound by Mamu-A1*002 for the ability to modulate Mamu-KIR3DL05+ NK cell responses. Twenty-eight of 75 SIV peptides bound by Mamu-A1*002 suppressed the cytolytic activity of primary Mamu-KIR3DL05+ NK cells, including three immunodominant CD8+ T cell epitopes previously shown to stabilize Mamu-A1*002 tetramer binding to Mamu-KIR3DL05. Substitutions at C-terminal positions changed inhibitory peptides into disinhibitory peptides, and vice versa, without altering binding to Mamu-A1*002. The functional effects of these peptide variants on NK cell responses also corresponded to their effects on Mamu-A1*002 tetramer binding to Mamu-KIR3DL05. In assays with mixtures of inhibitory and disinhibitory peptides, low concentrations of inhibitory peptides dominated to suppress NK cell responses. Consistent with the inhibition of Mamu-KIR3DL05+ NK cells by viral epitopes presented by Mamu-A1*002, SIV replication was significantly higher in Mamu-A1*002+ CD4+ lymphocytes co-cultured with Mamu-KIR3DL05+ NK cells than with Mamu-KIR3DL05- NK cells. These results demonstrate that viral peptides can differentially affect NK cell responses by modulating MHC class I interactions with inhibitory KIRs, and provide a mechanism by which immunodeficiency viruses may evade NK cell responses.

  8. Investigation of the structural requirements of K-Ras(G12D) selective inhibitory peptide KRpep-2d using alanine scans and cysteine bridging.

    Science.gov (United States)

    Niida, Ayumu; Sasaki, Shigekazu; Yonemori, Kazuko; Sameshima, Tomoya; Yaguchi, Masahiro; Asami, Taiji; Sakamoto, Kotaro; Kamaura, Masahiro

    2017-06-15

    A structure-activity relationship study of a K-Ras(G12D) selective inhibitory cyclic peptide, KRpep-2d was performed. Alanine scanning of KRpep-2d focusing on the cyclic moiety showed that Leu 7 , Ile 9 , and Asp 12 are the key elements for K-Ras(G12D) selective inhibition of KRpep-2d. The cysteine bridging was also examined to identify the stable analog of KRpep-2d under reductive conditions. As a result, the KRpep-2d analog (12) including mono-methylene bridging showed potent K-Ras(G12D) selective inhibition in both the presence and the absence of dithiothreitol. This means that mono-methylene bridging is an effective strategy to obtain a reduction-resistance analog of parent disulfide cyclic peptides. Peptide 12 inhibited proliferation of K-Ras(G12D)-driven cancer cells significantly. These results gave valuable information for further optimization of KRpep-2d to provide novel anti-cancer drug candidates targeting the K-Ras(G12D) mutant. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. A novel chimeric peptide with antimicrobial activity.

    Science.gov (United States)

    Alaybeyoglu, Begum; Akbulut, Berna Sariyar; Ozkirimli, Elif

    2015-04-01

    Beta-lactamase-mediated bacterial drug resistance exacerbates the prognosis of infectious diseases, which are sometimes treated with co-administration of beta-lactam type antibiotics and beta-lactamase inhibitors. Antimicrobial peptides are promising broad-spectrum alternatives to conventional antibiotics in this era of evolving bacterial resistance. Peptides based on the Ala46-Tyr51 beta-hairpin loop of beta-lactamase inhibitory protein (BLIP) have been previously shown to inhibit beta-lactamase. Here, our goal was to modify this peptide for improved beta-lactamase inhibition and cellular uptake. Motivated by the cell-penetrating pVEC sequence, which includes a hydrophobic stretch at its N-terminus, our approach involved the addition of LLIIL residues to the inhibitory peptide N-terminus to facilitate uptake. Activity measurements of the peptide based on the 45-53 loop of BLIP for enhanced inhibition verified that the peptide was a competitive beta-lactamase inhibitor with a K(i) value of 58 μM. Incubation of beta-lactam-resistant cells with peptide decreased the number of viable cells, while it had no effect on beta-lactamase-free cells, indicating that this peptide had antimicrobial activity via beta-lactamase inhibition. To elucidate the molecular mechanism by which this peptide moves across the membrane, steered molecular dynamics simulations were carried out. We propose that addition of hydrophobic residues to the N-terminus of the peptide affords a promising strategy in the design of novel antimicrobial peptides not only against beta-lactamase but also for other intracellular targets. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd.

  10. Prime-Boost Vaccination Using Chemokine-Fused gp120 DNA and HIV Envelope Peptides Activates Both Immediate and Long-Term Memory Cellular Responses in Rhesus Macaques

    Directory of Open Access Journals (Sweden)

    Hong Qin

    2010-01-01

    Full Text Available HIV vaccine candidates with improved immunogenicity and induction of mucosal T-cell immunity are needed. A prime-boost strategy using a novel HIV glycoprotein 120 DNA vaccine was employed to immunize rhesus macaques. The DNA vaccine encoded a chimeric gp120 protein in fusion with monocyte chemoattractant protein-3, which was hypothesized to improve the ability of antigen-presenting cells to capture viral antigen through chemokine receptor-mediated endocytosis. DNA vaccination induced virus-reactive T cells in peripheral blood, detectable by T cell proliferation, INFγ ELISPOT and sustained IL-6 production, without humoral responses. With a peptide-cocktail vaccine containing a set of conserved polypeptides of HIV-1 envelope protein, given by nasogastric administration, primed T-cell immunity was significantly boosted. Surprisingly, long-term and peptide-specific mucosal memory T-cell immunity was detected in both vaccinated macaques after one year. Therefore, data from this investigation offer proof-of-principle for potential effectiveness of the prime-boost strategy with a chemokine-fused gp120 DNA and warrant further testing in the nonhuman primate models for developing as a potential HIV vaccine candidate in humans.

  11. The binding mechanism of a peptidic cyclic serine protease inhibitor

    DEFF Research Database (Denmark)

    Jiang, Longguang; Svane, Anna Sigrid P.; Sørensen, Hans Peter

    2011-01-01

    Serine proteases are classical objects for studies of catalytic and inhibitory mechanisms as well as interesting as therapeutic targets. Since small-molecule serine protease inhibitors generally suffer from specificity problems, peptidic inhibitors, isolated from phage-displayed peptide libraries......, have attracted considerable attention. Here, we have investigated the mechanism of binding of peptidic inhibitors to serine protease targets. Our model is upain-1 (CSWRGLENHRMC), a disulfide-bond-constrained competitive inhibitor of human urokinase-type plasminogen activator with a noncanonical...... inhibitory mechanism and an unusually high specificity. Using a number of modified variants of upain-1, we characterised the upain-1-urokinase-type plasminogen activator complex using X-ray crystal structure analysis, determined a model of the peptide in solution by NMR spectroscopy, and analysed binding...

  12. About a New Type of Fuse Based on the Controllable Fusing Effect

    Directory of Open Access Journals (Sweden)

    PLESCA, A.

    2009-06-01

    Full Text Available Fuses are among the best known of electrical devices and there are an extremely large number in use throughout the world. Beside of the advantageous features, the nowadays fuses have certain drawbacks. Therefore, a new type of fuse based on controllable fusing concept is proposed and a study as regards the total clearing time is done. The new concept has been validated through many experimental tests at different current values. The new type of fuse based on controllable fusing concept can be integrated within an overcurrent protection system especially to protect power semiconductors where the Joule integral criterion is better satisfied.

  13. Peptide profiling and the bioactivity character of yogurt in the simulated gastrointestinal digestion.

    Science.gov (United States)

    Jin, Yan; Yu, Yang; Qi, Yanxia; Wang, Fangjun; Yan, Jiaze; Zou, Hanfa

    2016-06-01

    This study investigated the relationship between peptide profiles and the bioactivity character of yogurt in simulated gastrointestinal trials. A total of 250, 434 and 466 peptides were identified by LC-MS/MS analyses of yogurt, gastric digest and pancreatic digest. Forty peptides of yogurt survived in gastrointestinal digestion. κ-CN and β-CN contributed the diversity of peptides during the fermentation process and gastrointestinal digestion, respectively. The favorite of κ-CN by lactic acid bacteria complemented gut digestion by hydrolyzing κ-CN, the low abundance milk proteins. The potential bioactivities were evaluated by in vitro ACE and DPP-IV inhibition assays. The ACE inhibition rate of the pancreatic digests was ~4 - and ~2 - fold greater than that of yogurt and the gastric digests. The ACE inhibitory peptides generated during gastrointestinal digestion improved the ACE inhibitory activity of the gastric and pancreatic digests. The DPP-IV inhibition rate of the pancreatic digest was ~6 - and ~3 - fold greater than that of yogurt and the gastric digest. The numbers of potential DPP-IV inhibitory peptides were positively correlated to the DPP-IV inhibitory activity of the gastric and pancreatic digests. The present study describes the characters and bioactivities of peptides from yogurt in a simulated gastrointestinal digestion. The number of peptides identified from yogurt and gastrointestinal digests by LC-MS/MS increased in the simulated gastrointestinal trials. The in vitro ACE and DPP-IV inhibition bioactivities revealed that the bioactivity of yogurt was enhanced during gastrointestinal digestion. The correlation between peptides and bioactivity in vitro indicated that not only the peptides amount but also the proportion of peptides with high bioactivities contributed to increased bioactivity during gastrointestinal digestion. The study of peptides identified from yogurt and digests revealed that the number of released peptides was not determined

  14. Optimization of the recombinant production and purification of a self-assembling peptide in Escherichia coli

    NARCIS (Netherlands)

    Rad-Malekshahi, Mazda; Flement, Matthias; Hennink, Wim E.; Mastrobattista, Enrico

    2014-01-01

    Background: Amphiphilic peptides are important building blocks to generate nanostructured biomaterials for drug delivery and tissue engineering applications. We have shown that the self-assembling peptide SA2 (Ac-AAVVLLLWEE) can be recombinantly produced in E. coli when fused to the small

  15. Peptide Extracts from Cultures of Certain Lactobacilli Inhibit Helicobacter pylori.

    Science.gov (United States)

    De Vuyst, Luc; Vincent, Pascal; Makras, Eleftherios; Leroy, Frédéric; Pot, Bruno

    2010-03-01

    Helicobacter pylori inhibition by probiotic lactobacilli has been observed in vitro and in vivo. Carefully selected probiotic Lactobacillus strains could therefore play an important role in the treatment of H. pylori infection and eradication. However, the underlying mechanism for this inhibition is not clear. The aim of this study was to examine if peptide extracts, containing bacteriocins or other antibacterial peptides, from six Lactobacillus cultures (Lactobacillus acidophilus La1, Lactobacillus amylovorus DCE 471, Lactobacillus casei YIT 9029, Lactobacillus gasseri K7, Lactobacillus johnsonii La1, and Lactobacillus rhamnosus GG) contribute to the inhibition of H. pylori. Peptide extracts from cultures of Lact. amylovorus DCE 471 and Lact. johnsonii La1 were most active, reducing the viability of H. pylori ATCC 43504 with more than 2 log units within 4 h of incubation (P < 0.001). The four other extracts were less or not active. When six clinical isolates of H. pylori were tested for their susceptibility towards five inhibitory peptide extracts, similar observations were made. Again, the peptide extracts from Lact. amylovorus DCE 471 and Lact. johnsonii La1 were the most inhibitory, while the three other extracts resulted in a much lower inhibition of H. pylori. Protease-treated extracts were inactive towards H. pylori, confirming the proteinaceous nature of the inhibitory substance.

  16. Hippocampal Infusion of Zeta Inhibitory Peptide Impairs Recent, but Not Remote, Recognition Memory in Rats

    Directory of Open Access Journals (Sweden)

    Jena B. Hales

    2015-01-01

    Full Text Available Spatial memory in rodents can be erased following the infusion of zeta inhibitory peptide (ZIP into the dorsal hippocampus via indwelling guide cannulas. It is believed that ZIP impairs spatial memory by reversing established late-phase long-term potentiation (LTP. However, it is unclear whether other forms of hippocampus-dependent memory, such as recognition memory, are also supported by hippocampal LTP. In the current study, we tested recognition memory in rats following hippocampal ZIP infusion. In order to combat the limited targeting of infusions via cannula, we implemented a stereotaxic approach for infusing ZIP throughout the dorsal, intermediate, and ventral hippocampus. Rats infused with ZIP 3–7 days after training on the novel object recognition task exhibited impaired object recognition memory compared to control rats (those infused with aCSF. In contrast, rats infused with ZIP 1 month after training performed similar to control rats. The ability to form new memories after ZIP infusions remained intact. We suggest that enhanced recognition memory for recent events is supported by hippocampal LTP, which can be reversed by hippocampal ZIP infusion.

  17. Isolation and structural analysis of antihypertensive peptides that exist naturally in Gouda cheese.

    Science.gov (United States)

    Saito, T; Nakamura, T; Kitazawa, H; Kawai, Y; Itoh, T

    2000-07-01

    Seven kinds of ripened cheeses (8-mo-aged and 24-mo-aged Gouda, Emmental, Blue, Camembert, Edam, and Havarti) were homogenized with distilled water, and water-soluble peptides were prepared by C-18 hydrophobic chromatography. The inhibitory activity to angiotensin I-converting enzyme and decrease in the systolic blood pressure in spontaneously hypertensive rats were measured before and after oral administration of each peptide sample. The strongest depressive effect in the systolic blood pressure (-24.7 mm Hg) and intensive inhibitory activity to angiotensin I-converting enzyme (75.7%) were detected in the peptides from 8-mo-aged Gouda cheese. Four peptides were isolated by HPLC with reverse-phase and gel filtration modes. Their chemical structures and origins, clarified by combination analyses of protein sequencing, amino acid composition, and mass spectrometry, were as follows: peptide A, Arg-Pro-Lys-His-Pro-Ile-Lys-His-Gln [alpha(s1)-casein (CN), B-8P; f 1-9]; peptide B, Arg-Pro-Lys-His-Pro-Ile-Lys-His-Gln-Gly-Leu-Pro-Gln (alpha(s1)-CN, B-8P; f 1-13); peptide F, Tyr-Pro-Phe-Pro-Gly-Pro-Ile-Pro-Asn (beta-CN, A2-5P; f 60-68); and peptide G, Met-Pro-Phe-Pro-Lys-Tyr-Pro-Val-Gln-Pro-Phe (beta-CN, A2-5P; f 109-119). Peptides A and F, which were chemically synthesized, showed potent angiotensin I-converting enzyme inhibitory activity with little antihypertensive effects.

  18. Molecular pathways underlying inhibitory effect of antimicrobial peptide Nal-P-113 on bacteria biofilms formation of Porphyromonas gingivalis W83 by DNA microarray.

    Science.gov (United States)

    Wang, Hong-Yan; Lin, Li; Tan, Li-Si; Yu, Hui-Yuan; Cheng, Jya-Wei; Pan, Ya-Ping

    2017-02-17

    Wound-related infection remains a major challenge for health professionals. One disadvantage in conventional antibiotics is their inability to penetrate biofilms, the main protective strategy for bacteria to evade irradiation. Previously, we have shown that synthetic antimicrobial peptides could inhibit bacterial biofilms formation. In this study, we first delineated how Nal-P-113, a novel antimicrobial peptide, exerted its inhibitory effects on Porphyromonas gingivalis W83 biofilms formation at a low concentration. Secondly, we performed gene expression profiling and validated that Nal-P-113 at a low dose significantly down-regulated genes related to mobile and extrachromosomal element functions, transport and binding proteins in Porphyromonas gingivalis W83. These findings suggest that Nal-P-113 at low dose is sufficient to inhibit the formation of biofilms although Porphyromonas gingivalis W83 may maintain its survival in the oral cavity. The newly discovered molecular pathways may add the knowledge of developing a new strategy to target bacterial infections in combination with current first-line treatment in periodontitis.

  19. Gastrointestinal Endogenous Proteins as a Source of Bioactive Peptides - An In Silico Study

    Science.gov (United States)

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

    2014-01-01

    Dietary proteins are known to contain bioactive peptides that are released during digestion. Endogenous proteins secreted into the gastrointestinal tract represent a quantitatively greater supply of protein to the gut lumen than those of dietary origin. Many of these endogenous proteins are digested in the gastrointestinal tract but the possibility that these are also a source of bioactive peptides has not been considered. An in silico prediction method was used to test if bioactive peptides could be derived from the gastrointestinal digestion of gut endogenous proteins. Twenty six gut endogenous proteins and seven dietary proteins were evaluated. The peptides present after gastric and intestinal digestion were predicted based on the amino acid sequence of the proteins and the known specificities of the major gastrointestinal proteases. The predicted resultant peptides possessing amino acid sequences identical to those of known bioactive peptides were identified. After gastrointestinal digestion (based on the in silico simulation), the total number of bioactive peptides predicted to be released ranged from 1 (gliadin) to 55 (myosin) for the selected dietary proteins and from 1 (secretin) to 39 (mucin-5AC) for the selected gut endogenous proteins. Within the intact proteins and after simulated gastrointestinal digestion, angiotensin converting enzyme (ACE)-inhibitory peptide sequences were the most frequently observed in both the dietary and endogenous proteins. Among the dietary proteins, after in silico simulated gastrointestinal digestion, myosin was found to have the highest number of ACE-inhibitory peptide sequences (49 peptides), while for the gut endogenous proteins, mucin-5AC had the greatest number of ACE-inhibitory peptide sequences (38 peptides). Gut endogenous proteins may be an important source of bioactive peptides in the gut particularly since gut endogenous proteins represent a quantitatively large and consistent source of protein. PMID:24901416

  20. Gastrointestinal endogenous proteins as a source of bioactive peptides--an in silico study.

    Science.gov (United States)

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

    2014-01-01

    Dietary proteins are known to contain bioactive peptides that are released during digestion. Endogenous proteins secreted into the gastrointestinal tract represent a quantitatively greater supply of protein to the gut lumen than those of dietary origin. Many of these endogenous proteins are digested in the gastrointestinal tract but the possibility that these are also a source of bioactive peptides has not been considered. An in silico prediction method was used to test if bioactive peptides could be derived from the gastrointestinal digestion of gut endogenous proteins. Twenty six gut endogenous proteins and seven dietary proteins were evaluated. The peptides present after gastric and intestinal digestion were predicted based on the amino acid sequence of the proteins and the known specificities of the major gastrointestinal proteases. The predicted resultant peptides possessing amino acid sequences identical to those of known bioactive peptides were identified. After gastrointestinal digestion (based on the in silico simulation), the total number of bioactive peptides predicted to be released ranged from 1 (gliadin) to 55 (myosin) for the selected dietary proteins and from 1 (secretin) to 39 (mucin-5AC) for the selected gut endogenous proteins. Within the intact proteins and after simulated gastrointestinal digestion, angiotensin converting enzyme (ACE)-inhibitory peptide sequences were the most frequently observed in both the dietary and endogenous proteins. Among the dietary proteins, after in silico simulated gastrointestinal digestion, myosin was found to have the highest number of ACE-inhibitory peptide sequences (49 peptides), while for the gut endogenous proteins, mucin-5AC had the greatest number of ACE-inhibitory peptide sequences (38 peptides). Gut endogenous proteins may be an important source of bioactive peptides in the gut particularly since gut endogenous proteins represent a quantitatively large and consistent source of protein.

  1. De novo design and engineering of non-ribosomal peptide synthetases

    Science.gov (United States)

    Bozhüyük, Kenan A. J.; Fleischhacker, Florian; Linck, Annabell; Wesche, Frank; Tietze, Andreas; Niesert, Claus-Peter; Bode, Helge B.

    2018-03-01

    Peptides derived from non-ribosomal peptide synthetases (NRPSs) represent an important class of pharmaceutically relevant drugs. Methods to generate novel non-ribosomal peptides or to modify peptide natural products in an easy and predictable way are therefore of great interest. However, although the overall modular structure of NRPSs suggests the possibility of adjusting domain specificity and selectivity, only a few examples have been reported and these usually show a severe drop in production titre. Here we report a new strategy for the modification of NRPSs that uses defined exchange units (XUs) and not modules as functional units. XUs are fused at specific positions that connect the condensation and adenylation domains and respect the original specificity of the downstream module to enable the production of the desired peptides. We also present the use of internal condensation domains as an alternative to other peptide-chain-releasing domains for the production of cyclic peptides.

  2. Multimerized CHR-derived peptides as HIV-1 fusion inhibitors.

    Science.gov (United States)

    Nomura, Wataru; Hashimoto, Chie; Suzuki, Takaharu; Ohashi, Nami; Fujino, Masayuki; Murakami, Tsutomu; Yamamoto, Naoki; Tamamura, Hirokazu

    2013-08-01

    To date, several HIV-1 fusion inhibitors based on the carboxy-terminal leucine/isoleucine heptad repeat (CHR) region of an HIV-1 envelope protein gp41 have been discovered. We have shown that a synthetic peptide mimetic of a trimer form of the CHR-derived peptide C34 has potent inhibitory activity against the HIV-1 fusion mechanism, compared to a monomer C34 peptide. The present study revealed that a dimeric form of C34 is evidently structurally critical for fusion inhibitors, and that the activity of multimerized CHR-derived peptides in fusion inhibition is affected by the properties of the unit peptides C34, SC34EK, and T20. The fluorescence-based study suggested that the N36-interactive sites of the C34 trimer, including hydrophobic residues, are exposed outside the trimer and that trimerization of C34 caused a remarkable increase in fusion inhibitory activity. The present results could be useful in the design of fusion inhibitors against viral infections which proceed via membrane fusion with host cells. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  3. Bioactive Peptides from Muscle Sources: Meat and Fish

    Directory of Open Access Journals (Sweden)

    Catherine Stanton

    2011-08-01

    Full Text Available Bioactive peptides have been identified in a range of foods, including plant, milk and muscle, e.g., beef, chicken, pork and fish muscle proteins. Bioactive peptides from food proteins offer major potential for incorporation into functional foods and nutraceuticals. The aim of this paper is to present an outline of the bioactive peptides identified in the muscle protein of meat to date, with a focus on muscle protein from domestic animals and fish. The majority of research on bioactives from meat sources has focused on angiotensin-1-converting enzyme (ACE inhibitory and antioxidant peptides.

  4. Potential of a renin inhibitory peptide from the red seaweed Palmaria palmata as a functional food ingredient following confirmation and characterization of a hypotensive effect in spontaneously hypertensive rats.

    Science.gov (United States)

    Fitzgerald, Ciaran; Aluko, Rotimi E; Hossain, Mohammad; Rai, Dilip K; Hayes, Maria

    2014-08-20

    This work examined the resistance of the renin inhibitory, tridecapeptide IRLIIVLMPILMA derived previously from a Palmaria palmata papain hydrolysate, during gastrointestinal (GI) transit. Following simulated GI digestion, breakdown products were identified using mass spectrometry analysis and the known renin and angiotensin I converting enzyme inhibitory dipeptide IR was identified. In vivo animal studies using spontaneously hypertensive rats (SHRs) were used to confirm the antihypertensive effects of both the tridecapeptide IRLIIVLMPILMA and the seaweed protein hydrolysate from which this peptide was isolated. After 24 h, the SHR group fed the P. palmata protein hydrolysate recorded a drop of 34 mm Hg in systolic blood pressure (SBP) from 187 (±0.25) to 153 (± 0.64) mm Hg SBP, while the group fed the tridecapeptide IRLIIVLMPLIMA presented a drop of 33 mm Hg in blood pressure from 187 (±0.95) to 154 (±0.94) mm Hg SBP compared to the SBP recorded at time zero. The results of this study indicate that the seaweed protein derived hydrolysate has potential for use as antihypertensive agents and that the tridecapeptide is cleaved and activated to the dipeptide IR when it travels through the GI tract. Both the hydrolysate and peptide reduced SHR blood pressure when administered orally over a 24 h period.

  5. Identification of ace inhibitory cryptides in Tilapia protein hydrolysate by UPLC-MS/MS coupled to database analysis.

    Science.gov (United States)

    Yesmine, Ben Henda; Antoine, Bonnet; da Silva Ortência Leocádia, Nunes Gonzalez; Rogério, Boscolo Wilson; Ingrid, Arnaudin; Nicolas, Bridiau; Thierry, Maugard; Jean-Marie, Piot; Frédéric, Sannier; Stéphanie, Bordenave-Juchereau

    2017-05-01

    An ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry method was developed and applied to identify short angiotensin-I-converting enzyme (ACE) inhibitory cryptides in Tilapia (Oreochromis Niloticus) protein hydrolyzate. A database was created with previously identified ACE-inhibitory di- and tripeptides and the lowest molecular weight fraction of Tilapia hydrolysate was analysed for coincidences. Only VW and VY were identified. Further analysis of collected fractions conducted to the identification of 51 different peptides in major fractions. 19 peptides selected were synthesised and tested for their ACE inhibitory potential. TL, TI, IK, LR, LD, IQ, DI, AILE, ALLE, ALIE and AIIE were identified as new ACE inhibitors. The findings from this study point UPLC-MS/MS combined with the creation of a database as an efficient technique to identify specific short peptides within a complex hydrolysate, in addition with de novo sequencing. This efficient characterisation of bioactive factors like cryptides in protein hydrolysates will extend their use as functional foods. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Gephyrin-binding peptides visualize postsynaptic sites and modulate neurotransmission

    DEFF Research Database (Denmark)

    Maric, Hans Michael; Hausrat, Torben Johann; Neubert, Franziska

    2017-01-01

    is associated with perturbation of the basic physiological action. Here we pursue a fundamentally different approach, by instead targeting the intracellular receptor-gephyrin interaction. First, we defined the gephyrin peptide-binding consensus sequence, which facilitated the development of gephyrin super......-binding peptides and later effective affinity probes for the isolation of native gephyrin. Next, we demonstrated that fluorescent super-binding peptides could be used to directly visualize inhibitory postsynaptic sites for the first time in conventional and super-resolution microscopy. Finally, we demonstrate...

  7. 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.

  8. Memory Retrieval Has a Dynamic Influence on the Maintenance Mechanisms That Are Sensitive to ζ-Inhibitory Peptide (ZIP).

    Science.gov (United States)

    Levitan, David; Fortis-Santiago, Yaihara; Figueroa, Joshua A; Reid, Emily E; Yoshida, Takashi; Barry, Nicholas C; Russo, Abigail; Katz, Donald B

    2016-10-12

    In neuroscientists' attempts to understand the long-term storage of memory, topics of particular importance and interest are the cellular and system mechanisms of maintenance (e.g., those sensitive to ζ-inhibitory peptide, ZIP) and those induced by memory retrieval (i.e., reconsolidation). Much is known about each of these processes in isolation, but less is known concerning how they interact. It is known that ZIP sensitivity and memory retrieval share at least some molecular targets (e.g., recycling α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid, AMPA, receptors to the plasma membrane); conversely, the fact that sensitivity to ZIP emerges only after consolidation ends suggests that consolidation (and by extension reconsolidation) and maintenance might be mutually exclusive processes, the onset of one canceling the other. Here, we use conditioned taste aversion (CTA) in rats, a cortically dependent learning paradigm, to test this hypothesis. First, we demonstrate that ZIP infusions into gustatory cortex begin interfering with CTA memory 43-45 h after memory acquisition-after consolidation ends. Next, we show that a retrieval trial administered after this time point interrupts the ability of ZIP to induce amnesia and that ZIP's ability to induce amnesia is reengaged only 45 h after retrieval. This pattern of results suggests that memory retrieval and ZIP-sensitive maintenance mechanisms are mutually exclusive and that the progression from one to the other are similar after acquisition and retrieval. They also reveal concrete differences between ZIP-sensitive mechanisms induced by acquisition and retrieval: the latency with which ZIP-sensitive mechanisms are expressed differ for the two processes. Memory retrieval and the molecular mechanisms that are sensitive to ζ-inhibitory peptide (ZIP) are the few manipulations that have been shown to effect memory maintenance. Although much is known about their effect on maintenance separately, it is unknown how they

  9. Novel phospholipase A2 inhibitors from python serum are potent peptide antibiotics.

    Science.gov (United States)

    Samy, Ramar Perumal; Thwin, Maung Maung; Stiles, Brad G; Satyanarayana-Jois, Seetharama; Chinnathambi, Arunachalam; Zayed, M E; Alharbi, Sulaiman Ali; Siveen, Kodappully Sivaraman; Sikka, Sakshi; Kumar, Alan Prem; Sethi, Gautam; Lim, Lina Hsiu Kim

    2015-04-01

    Antimicrobial peptides (AMPs) play a vital role in defense against resistant bacteria. In this study, eight different AMPs synthesized from Python reticulatus serum protein were tested for bactericidal activity against various Gram-positive and Gram-negative bacteria (Staphylococcus aureus, Burkholderia pseudomallei (KHW and TES strains), and Proteus vulgaris) using a disc-diffusion method (20 μg/disc). Among the tested peptides, phospholipase A2 inhibitory peptide (PIP)-18[59-76], β-Asp65-PIP[59-67], D-Ala66-PNT.II, and D60,65E-PIP[59-67] displayed the most potent bactericidal activity against all tested pathogens in a dose-dependent manner (100-6.8 μg/ml), with a remarkable activity noted against S. aureus at 6.8 μg/ml dose within 6 h of incubation. Determination of minimum inhibitory concentrations (MICs) by a micro-broth dilution method at 100-3.125 μg/ml revealed that PIP-18[59-76], β-Asp65-PIP[59-67] and D-Ala66-PNT.II peptides exerted a potent inhibitory effect against S. aureus and B. pseudomallei (KHW) (MICs 3.125 μg/ml), while a much less inhibitory potency (MICs 12.5 μg/ml) was noted for β-Asp65-PIP[59-67] and D-Ala66-PNT.II peptides against B. pseudomallei (TES). Higher doses of peptides had no effect on the other two strains (i.e., Klebsiella pneumoniae and Streptococcus pneumoniae). Overall, PIP-18[59-76] possessed higher antimicrobial activity than that of chloramphenicol (CHL), ceftazidime (CF) and streptomycin (ST) (30 μg/disc). When the two most active peptides, PIP-18[59-76] and β-Asp65-PIP[59-67], were applied topically at a 150 mg/kg dose for testing wound healing activity in a mouse model of S. aureus infection, the former accelerates faster wound healing than the latter peptide at 14 days post-treatment. The western blot data suggest that the topical application of peptides (PIP-18[59-67] and β-Asp65-PIP[59-67]) modulates NF-kB mediated wound repair in mice with relatively little haemolytic (100-1.56 μg/ml) and cytotoxic (1000

  10. Dihydropyridine-fused and pyridine-fused coumarins: Reduction on a glassy carbon electrode in dimethylformamide

    International Nuclear Information System (INIS)

    Nuñez-Vergara, Luis J.; Pardo-Jiménez, V.; Barrientos, C.; Olea-Azar, C.A.; Navarrete-Encina, P.A.; Squella, J.A.

    2012-01-01

    In this study, two series of dihydropyridine-fused and pyridine-fused coumarins were synthesised and electrochemically characterised in aprotic medium. In both series, the most easily reducible groups were the endocyclic carbonyl groups. The electrochemical mechanism for both types of compounds is strongly dependent on the experimental time-scale. Cyclic voltammetric (CV) reduction on a glassy carbon electrode (GCE) of the endocyclic carbonyl group of dihydropyridine-fused coumarins involves an ECEC mechanism with two electron transfer steps that are coupled with chemical reactions to produce the corresponding hemiacetal derivative. In the case of pyridine-fused coumarins, CV reduction of the endocyclic carbonyl group involves an EEC mechanism. ESR studies revealed the presence of a stabilised intermediate only for the pyridine-fused derivatives. Our theoretical study showed a spin density map of radical species delocalised mainly within the coumarin ring, indicating the reduction of the endocyclic carbonyl group. In the case of the dihydropyridine-fused derivatives, the mildly acid hydrogen of the dihydropyridine ring destabilises the radical via a father–son type reaction.

  11. Insight into eukaryotic topoisomerase II-inhibiting fused heterocyclic compounds in human cancer cell lines by molecular docking.

    Science.gov (United States)

    Taskin, T; Yilmaz, S; Yildiz, I; Yalcin, I; Aki, E

    2012-01-01

    Etoposide is effective as an anti-tumour drug by inhibiting eukaryotic DNA topoisomerase II via establishing a covalent complex with DNA. Unfortunately, its wide therapeutic application is often hindered by multidrug resistance (MDR), low water solubility and toxicity. In our previous study, new derivatives of benzoxazoles, benzimidazoles and related fused heterocyclic compounds, which exhibited significant eukaryotic DNA topoisomerase II inhibitory activity, were synthesized and exhibited better inhibitory activity compared with the drug etoposide itself. To expose the binding interactions between the eukaryotic topoisomerase II and the active heterocyclic compounds, docking studies were performed, using the software Discovery Studio 2.1, based on the crystal structure of the Topo IIA-bound G-segment DNA (PDB ID: 2RGR). The research was conducted on a selected set of 31 fused heterocyclic compounds with variation in structure and activity. The structural analyses indicate coordinate and hydrogen bonding interactions, van der Waals interactions and hydrophobic interactions between ligands and the protein, as Topo IIA-bound G-segment DNA are responsible for the preference of inhibition and potency. Collectively, the results demonstrate that the compounds 1a, 1c, 3b, 3c, 3e and 4a are significant anti-tumour drug candidates that should be further studied.

  12. Peptide profiling of bovine kefir reveals 236 unique peptides released from caseins during its production by starter culture or kefir grains.

    Science.gov (United States)

    Ebner, Jennifer; Aşçı Arslan, Ayşe; Fedorova, Maria; Hoffmann, Ralf; Küçükçetin, Ahmet; Pischetsrieder, Monika

    2015-03-18

    Kefir has a long tradition in human nutrition due to its presupposed health promoting effects. To investigate the potential contribution of bioactive peptides to the physiological effects of kefir, comprehensive analysis of the peptide profile was performed by nano-ESI-LTQ-Orbitrap MS coupled to nano-ultrahigh-performance liquid chromatography. Thus, 257 peptides were identified, mainly released from β-casein, followed by αS1-, κ-, and αS2-casein. Most (236) peptides were uniquely detected in kefir, but not in raw milk indicating that the fermentation step does not only increase the proteolytic activity 1.7- to 2.4-fold compared to unfermented milk, but also alters the composition of the peptide fraction. The influence of the microflora was determined by analyzing kefir produced from traditional kefir grains or commercial starter culture. Kefir from starter culture featured 230 peptide sequences and showed a significantly, 1.4-fold higher proteolytic activity than kefir from kefir grains with 127 peptides. A match of 97 peptides in both varieties indicates the presence of a typical kefir peptide profile that is not influenced by the individual composition of the microflora. Sixteen of the newly identified peptides were previously described as bioactive, including angiotensin-converting enzyme (ACE)-inhibitory, antimicrobial, immunomodulating, opioid, mineral binding, antioxidant, and antithrombotic effects. The present study describes a comprehensive peptide profile of kefir comprising 257 sequences. The peptide list was used to identify 16 bioactive peptides with ACE-inhibitory, antioxidant, antithrombotic, mineral binding, antimicrobial, immunomodulating and opioid activity in kefir. Furthermore, it was shown that a majority of the kefir peptides were not endogenously present in the raw material milk, but were released from milk caseins by proteases of the microbiota and are therefore specific for the product. Consequently, the proteolytic activity and the

  13. An anti-steroidogenic inhibitory primer pheromone in male sea lamprey (Petromyzon marinus)

    Science.gov (United States)

    Chung-Davidson, Yu-Wen; Wang, Huiyong; Bryan, Mara B.; Wu, Hong; Johnson, Nicholas S.; Li, Weiming

    2013-01-01

    Reproductive functions can be modulated by both stimulatory and inhibitory primer pheromones released by conspecifics. Many stimulatory primer pheromones have been documented, but relatively few inhibitory primer pheromones have been reported in vertebrates. The sea lamprey male sex pheromone system presents an advantageous model to explore the stimulatory and inhibitory primer pheromone functions in vertebrates since several pheromone components have been identified. We hypothesized that a candidate sex pheromone component, 7α, 12α-dihydroxy-5α-cholan-3-one-24-oic acid (3 keto-allocholic acid or 3kACA), exerts priming effects through the hypothalamic-pituitary-gonadal (HPG) axis. To test this hypothesis, we measured the peptide concentrations and gene expressions of lamprey gonadotropin releasing hormones (lGnRH) and the HPG output in immature male sea lamprey exposed to waterborne 3kACA. Exposure to waterborne 3kACA altered neuronal activation markers such as jun and jun N-terminal kinase (JNK), and lGnRH mRNA levels in the brain. Waterborne 3kACA also increased lGnRH-III, but not lGnRH-I or -II, in the forebrain. In the plasma, 3kACA exposure decreased all three lGnRH peptide concentrations after 1 h exposure. After 2 h exposure, 3kACA increased lGnRHI and -III, but decreased lGnRH-II peptide concentrations in the plasma. Plasma lGnRH peptide concentrations showed differential phasic patterns. Group housing condition appeared to increase the averaged plasma lGnRH levels in male sea lamprey compared to isolated males. Interestingly, 15α-hydroxyprogesterone (15α-P) concentrations decreased after prolonged 3kACA exposure (at least 24 h). To our knowledge, this is the only known synthetic vertebrate pheromone component that inhibits steroidogenesis in males.

  14. Identification of constrained peptides that bind to and preferentially inhibit the activity of the hepatitis C viral RNA-dependent RNA polymerase

    International Nuclear Information System (INIS)

    Amin, Anthony; Zaccardi, Joe; Mullen, Stanley; Olland, Stephane; Orlowski, Mark; Feld, Boris; Labonte, Patrick; Mak, Paul

    2003-01-01

    A class of disulfide constrained peptides containing a core motif FPWG was identified from a screen of phage displayed library using the HCV RNA-dependent RNA polymerase (NS5B) as a bait. Surface plasmon resonance studies showed that three highly purified synthetic constrained peptides bound to immobilized NS5B with estimated K d values ranging from 30 to 60 μM. In addition, these peptides inhibited the NS5B activity in vitro with IC 50 ranging from 6 to 48 μM, whereas in contrast they had no inhibitory effect on the enzymatic activities of calf thymus polymerase α, human polymerase β, RSV polymerase, and HIV reverse transcriptase in vitro. Two peptides demonstrated conformation-dependent inhibition since their synthetic linear versions were not inhibitory in the NS5B assay. A constrained peptide with the minimum core motif FPWG retained selective inhibition of NS5B activity with an IC 50 of 50 μM. Alanine scan analyses of a representative constrained peptide, FPWGNTW, indicated that residues F1 and W7 were critical for the inhibitory effect of this peptide, although residues P2 and N5 had some measurable inhibitory effect as well. Further analyses of the mechanism of inhibition indicated that these peptides inhibited the formation of preelongation complexes required for the elongation reaction. However, once the preelongation complex was formed, its activity was refractory to peptide inhibition. Furthermore, the constrained peptide FPWGNTW inhibited de novo initiated RNA synthesis by NS5B from a poly(rC) template. These data indicate that the peptides confer selective inhibition of NS5B activity by binding to the enzyme and perturbing an early step preceding the processive elongation step of RNA synthesis

  15. A cyclic peptidic serine protease inhibitor

    DEFF Research Database (Denmark)

    Zhao, Baoyu; Xu, Peng; Jiang, Longguang

    2014-01-01

    Peptides are attracting increasing interest as protease inhibitors. Here, we demonstrate a new inhibitory mechanism and a new type of exosite interactions for a phage-displayed peptide library-derived competitive inhibitor, mupain-1 (CPAYSRYLDC), of the serine protease murine urokinase...... pocket, its carbonyl group aligning improperly relative to Ser195 and the oxyanion hole, explaining why the peptide is an inhibitor rather than a substrate. Substitution of the P1 Arg with novel unnatural Arg analogues with aliphatic or aromatic ring structures led to an increased affinity, depending......, in spite of a less favorable binding entropy and loss of a polar interaction. We conclude that increased flexibility of the peptide allows more favorable exosite interactions, which, in combination with the use of novel Arg analogues as P1 residues, can be used to manipulate the affinity and specificity...

  16. E-Peptides Control Bioavailability of IGF-1

    Science.gov (United States)

    Piszczek, Agnieszka; Perlas, Emarald; Winn, Nadine; Nastasi, Tommaso; Rosenthal, Nadia

    2012-01-01

    Insulin-like growth factor 1 (IGF-1) is a potent cytoprotective growth factor that has attracted considerable attention as a promising therapeutic agent. Transgenic over-expression of IGF-1 propeptides facilitates protection and repair in a broad range of tissues, although transgenic mice over-expressing IGF-1 propeptides display little or no increase in IGF-1 serum levels, even with high levels of transgene expression. IGF-1 propeptides are encoded by multiple alternatively spliced transcripts including C-terminal extension (E) peptides, which are highly positively charged. In the present study, we use decellularized mouse tissue to show that the E-peptides facilitate in vitro binding of murine IGF-1 to the extracellular matrix (ECM) with varying affinities. This property is independent of IGF-1, since proteins consisting of the E-peptides fused to relaxin, a related member of the insulin superfamily, bound equally avidly to decellularized ECM. Thus, the E-peptides control IGF-1 bioavailability by preventing systemic circulation, offering a potentially powerful way to tether IGF-1 and other therapeutic proteins to the site of synthesis and/or administration. PMID:23251442

  17. 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.

  18. Milk-derived angiotensin-I-converting enzymeinhibitory peptides generated by Lactobacillus delbrueckii subsp. lactis CRL 581

    Directory of Open Access Journals (Sweden)

    Villegas Josefina M.

    2014-01-01

    Full Text Available Several strains of Lactobacillus helveticus and Lactobacillus delbrueckii subsp. lactis were evaluated for their ability to release angiotensin-I-converting enzyme (ACE inhibitory peptides from α-casein (α-CN and β-casein (β-CN. Casein peptides resulting from L. delbrueckii subsp. lactis CRL 581-mediated hydrolysis exhibited the highest ACE-inhibitory (ACEI activities, with values of 53 and 40% for α-CN and β-CN, respectively. The casein hydrolysates were fractionated by reversedphase high pressure liquid chromatography and some of the active peptides were identified by mass spectrometry. The fraction with the highest ACEI activity arose from β-CN and contained a mixture of the β-CN f194-206 (QEPVLGPVRGPFP and f198-206 (LGPVRGPFP peptides. Furthermore, the ACEI tripeptide IPP was identified in all β-CN hydrolysates; L. delbrueckii subsp. lactis CRL 581 produced the highest amount of this peptide. The bioactive peptides released by CRL 581 strain may be used in the formulation of functional foods and nutraceuticals, representing a healthier and natural alternative for regulating blood pressure.

  19. 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.

  20. Glucagon-like peptide-1 7-36 amide and peptide YY from the L-cell of the ileal mucosa are potent inhibitors of vagally induced gastric acid secretion in man

    DEFF Research Database (Denmark)

    Wettergren, A; Petersen, H; Orskov, C

    1994-01-01

    BACKGROUND: Glucagon-like peptide (GLP-1) 7-36 amide and peptide YY (PYY) from the L-cell of the ileal mucosa are potent inhibitors of gastric acid secretion in man. It is not clear, however, by which mechanism(s) they inhibit acid secretion. In dogs the inhibitory effect of PYY on acid secretion...

  1. In silico, in vitro and in vivo analyses of dipeptidyl peptidase IV inhibitory activity and the antidiabetic effect of sodium caseinate hydrolysate.

    Science.gov (United States)

    Hsieh, Cheng-Hong; Wang, Tzu-Yuan; Hung, Chuan-Chuan; Jao, Chia-Ling; Hsieh, You-Liang; Wu, Si-Xian; Hsu, Kuo-Chiang

    2016-02-01

    The frequency (A), a novel in silico parameter, was developed by calculating the ratio of the number of truncated peptides with Xaa-proline and Xaa-alanine to all peptide fragments from a protein hydrolyzed with a specific protease. The highest in vitro DPP-IV inhibitory activity (72.7%) was observed in the hydrolysate of sodium caseinate by bromelain (Cas/BRO), and the constituent proteins of bovine casein also had relatively high A values (0.10-0.17) with BRO hydrolysis. 1CBR (the <1 kDa fraction of Cas/BRO) showed the greatest in vitro DPP-IV inhibitory activity of 77.5% and was used for in vivo test by high-fat diet-fed and low-dose streptozotocin-induced diabetic rats. The daily administration of 1CBR for 6 weeks was effective to improve glycaemic control in diabetic rats. The results indicate that the novel in silico method has the potential as a screening tool to predict dietary proteins to generate DPP-IV inhibitory and antidiabetic peptides.

  2. Membrane interaction and secondary structure of de novo designed arginine-and tryptophan peptides with dual function

    KAUST Repository

    Rydberg, Hanna A.; Carlsson, Nils; Nordé n, Bengt

    2012-01-01

    of arg/trp peptides and investigated how the position and number of tryptophans affect cellular uptake. Here we explore the antimicrobial properties and the interaction with lipid model membranes of these peptides, using minimal inhibitory concentrations

  3. Novel Antimicrobial Peptides That Inhibit Gram Positive Bacterial Exotoxin Synthesis

    Science.gov (United States)

    Merriman, Joseph A.; Nemeth, Kimberly A.; Schlievert, Patrick M.

    2014-01-01

    Gram-positive bacteria, such as Staphylococcus aureus, cause serious human illnesses through combinations of surface virulence factors and secretion of exotoxins. Our prior studies using the protein synthesis inhibitor clindamycin and signal transduction inhibitors glycerol monolaurate and α-globin and β-globin chains of hemoglobin indicate that their abilities to inhibit exotoxin production by S. aureus are separable from abilities to inhibit growth of the organism. Additionally, our previous studies suggest that inhibition of exotoxin production, in absence of ability to kill S. aureus and normal flora lactobacilli, will prevent colonization by pathogenic S. aureus, while not interfering with lactobacilli colonization. These disparate activities may be important in development of novel anti-infective agents that do not alter normal flora. We initiated studies to explore the exotoxin-synthesis-inhibition activity of hemoglobin peptides further to develop potential agents to prevent S. aureus infections. We tested synthesized α-globin chain peptides, synthetic variants of α-globin chain peptides, and two human defensins for ability to inhibit exotoxin production without significantly inhibiting S. aureus growth. All of these peptides were weakly or not inhibitory to bacterial growth. However, the peptides were inhibitory to exotoxin production with increasing activity dependent on increasing numbers of positively-charged amino acids. Additionally, the peptides could be immobilized on agarose beads or have amino acid sequences scrambled and still retain exotoxin-synthesis-inhibition. The peptides are not toxic to human vaginal epithelial cells and do not inhibit growth of normal flora L. crispatus. These peptides may interfere with plasma membrane signal transduction in S. aureus due to their positive charges. PMID:24748386

  4. Rational and efficient preparation of a chimeric protein containing a tandem dimer of thrombopoietin mimetic peptide fused to human growth hormone in Escherichia coli.

    Science.gov (United States)

    Wang, Song; Shen, Mingqiang; Xu, Yang; Chen, Fang; Chen, Mo; Chen, Shilei; Wang, Aiping; Zhang, Zhou; Ran, Xinze; Cheng, Tianmin; Su, Yongping; Wang, Junping

    2013-04-01

    The 14-mer thrombopoietin mimetic peptide (TMP), especially in the form of dimer, displayed potent megakaryocytopoiesis activity in vitro. However, it is difficult to prepare such short peptide with high bioactivity through gene-engineering approaches. In this study, a chimeric protein containing a tandem dimer of TMP (dTMP) fused to human growth hormone (hGH), a kind of hematopoietic growth factor that activates the same signal pathways as thrombopoietin, was produced in Escherichia coli by soluble expression. By rational utilization of the XmnI and EcoRV restriction sites, a PCR fragment encoding dTMP-GH was inserted into the plasmid vector pMAL-p2X at the position right after Xa factor cleavage site, in frame with maltose-binding protein (MBP) gene. Under optimized conditions, a high-level expression of soluble MBP-dTMP-GH fusion protein was obtained. By application of amylose resin chromatography, Xa factor digestion, hydrophobic chromatography followed by gel filtration, the dTMP-GH fusion protein was separated. Finally, a relatively high yield of dTMP-GH fusion protein with high purity (>98%) and without redundant amino acid was achieved, as identified by high-performance liquid chromatography, mass spectrometry, and amino acid sequencing. The functional assays showed that dTMP-GH could promote the proliferation of megakaryoblast cells and maturation of murine megakaryocytes derived from bone marrow, in a dose-dependent manner. Moreover, an enhanced effect of dTMP-GH on megakaryocytopoiesis was found as compared with equimolar concentration of dTMP and rhGH. This work provides a new avenue to generate thrombopoietic agents based on TMP.

  5. Structural Principles in the Development of Cyclic Peptidic Enzyme Inhibitors

    Science.gov (United States)

    Xu, Peng; Andreasen, Peter A.; Huang, Mingdong

    2017-01-01

    This review summarizes our studies in the development of small cyclic peptides for specifically modulating enzyme activity. Serine proteases share highly similar active sites but perform diverse physiological and pathological functions. From a phage-display peptide library, we isolated two mono-cyclic peptides, upain-1 (CSWRGLENHRMC) and mupain-1 (CPAYSRYLDC), which inhibit the activity of human and murine urokinase-type plasminogen activators (huPA and muPA) with Ki values in the micromolar or sub-micromolar range, respectively. The following affinity maturations significantly enhanced the potencies of the two peptides, 10-fold and >250-fold for upain-1 and mupain-1, respectively. The most potent muPA inhibitor has a potency (Ki = 2 nM) and specificity comparable to mono-clonal antibodies. Furthermore, we also found an unusual feature of mupain-1 that its inhibitory potency can be enhanced by increasing the flexibility, which challenges the traditional viewpoint that higher rigidity leading to higher affinity. Moreover, by changing a few key residues, we converted mupain-1 from a uPA inhibitor to inhibitors of other serine proteases, including plasma kallikrein (PK) and coagulation factor XIa (fXIa). PK and fXIa inhibitors showed Ki values in the low nanomolar range and high specificity. Our studies demonstrate the versatility of small cyclic peptides to engineer inhibitory potency against serine proteases and to provide a new strategy for generating peptide inhibitors of serine proteases. PMID:29104489

  6. Fusion peptides from oncogenic chimeric proteins as putative specific biomarkers of cancer.

    Science.gov (United States)

    Conlon, Kevin P; Basrur, Venkatesha; Rolland, Delphine; Wolfe, Thomas; Nesvizhskii, Alexey I; MacCoss, Michael J; Lim, Megan S; Elenitoba-Johnson, Kojo S J

    2013-10-01

    Chromosomal translocations encoding chimeric fusion proteins constitute one of the most common mechanisms underlying oncogenic transformation in human cancer. Fusion peptides resulting from such oncogenic chimeric fusions, though unique to specific cancer subtypes, are unexplored as cancer biomarkers. Here we show, using an approach termed fusion peptide multiple reaction monitoring mass spectrometry, the direct identification of different cancer-specific fusion peptides arising from protein chimeras that are generated from the juxtaposition of heterologous genes fused by recurrent chromosomal translocations. Using fusion peptide multiple reaction monitoring mass spectrometry in a clinically relevant scenario, we demonstrate the specific, sensitive, and unambiguous detection of a specific diagnostic fusion peptide in clinical samples of anaplastic large cell lymphoma, but not in a diverse array of benign lymph nodes or other forms of primary malignant lymphomas and cancer-derived cell lines. Our studies highlight the utility of fusion peptides as cancer biomarkers and carry broad implications for the use of protein biomarkers in cancer detection and monitoring.

  7. Effects of gastric inhibitory polypeptide, glucagon-like peptide-1 and glucagon-like peptide-1 receptor agonists on Bone Cell Metabolism.

    Science.gov (United States)

    Hansen, Morten S S; Tencerova, Michaela; Frølich, Jacob; Kassem, Moustapha; Frost, Morten

    2018-01-01

    The relationship between gut and skeleton is increasingly recognized as part of the integrated physiology of the whole organism. The incretin hormones gastric inhibitory polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are secreted from the intestine in response to nutrient intake and exhibit several physiological functions including regulation of islet hormone secretion and glucose levels. A number of GLP-1 receptor agonists (GLP-1RAs) are currently used in treatment of type 2 diabetes and obesity. However, GIP and GLP-1 cognate receptors are widely expressed suggesting that incretin hormones mediate effects beyond control of glucose homeostasis, and reports on associations between incretin hormones and bone metabolism have emerged. The aim of this MiniReview was to provide an overview of current knowledge regarding the in vivo and in vitro effects of GIP and GLP-1 on bone metabolism. We identified a total of 30 pre-clinical and clinical investigations of the effects of GIP, GLP-1 and GLP-1RAs on bone turnover markers, bone mineral density (BMD), bone microarchitecture and fracture risk. Studies conducted in cell cultures and rodents demonstrated that GIP and GLP-1 play a role in regulating skeletal homeostasis, with pre-clinical data suggesting that GIP inhibits bone resorption whereas GLP-1 may promote bone formation and enhance bone material properties. These effects are not corroborated by clinical studies. While there is evidence of effects of GIP and GLP-1 on bone metabolism in pre-clinical investigations, clinical trials are needed to clarify whether similar effects are present and clinically relevant in humans. © 2017 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

  8. De novo peptide design and experimental validation of histone methyltransferase inhibitors.

    Directory of Open Access Journals (Sweden)

    James Smadbeck

    Full Text Available Histones are small proteins critical to the efficient packaging of DNA in the nucleus. DNA–protein complexes, known as nucleosomes, are formed when the DNA winds itself around the surface of the histones. The methylation of histone residues by enhancer of zeste homolog 2 (EZH2 maintains gene repression over successive cell generations. Overexpression of EZH2 can silence important tumor suppressor genes leading to increased invasiveness of many types of cancers. This makes the inhibition of EZH2 an important target in the development of cancer therapeutics. We employed a three-stage computational de novo peptide design method to design inhibitory peptides of EZH2. The method consists of a sequence selection stage and two validation stages for fold specificity and approximate binding affinity. The sequence selection stage consists of an integer linear optimization model that was solved to produce a rank-ordered list of amino acid sequences with increased stability in the bound peptide-EZH2 structure. These sequences were validated through the calculation of the fold specificity and approximate binding affinity of the designed peptides. Here we report the discovery of novel EZH2 inhibitory peptides using the de novo peptide design method. The computationally discovered peptides were experimentally validated in vitro using dose titrations and mechanism of action enzymatic assays. The peptide with the highest in vitro response, SQ037, was validated in nucleo using quantitative mass spectrometry-based proteomics. This peptide had an IC50 of 13.5 mM, demonstrated greater potency as an inhibitor when compared to the native and K27A mutant control peptides, and demonstrated competitive inhibition versus the peptide substrate. Additionally, this peptide demonstrated high specificity to the EZH2 target in comparison to other histone methyltransferases. The validated peptides are the first computationally designed peptides that directly inhibit EZH2

  9. De novo peptide design and experimental validation of histone methyltransferase inhibitors.

    Directory of Open Access Journals (Sweden)

    James Smadbeck

    Full Text Available Histones are small proteins critical to the efficient packaging of DNA in the nucleus. DNA-protein complexes, known as nucleosomes, are formed when the DNA winds itself around the surface of the histones. The methylation of histone residues by enhancer of zeste homolog 2 (EZH2 maintains gene repression over successive cell generations. Overexpression of EZH2 can silence important tumor suppressor genes leading to increased invasiveness of many types of cancers. This makes the inhibition of EZH2 an important target in the development of cancer therapeutics. We employed a three-stage computational de novo peptide design method to design inhibitory peptides of EZH2. The method consists of a sequence selection stage and two validation stages for fold specificity and approximate binding affinity. The sequence selection stage consists of an integer linear optimization model that was solved to produce a rank-ordered list of amino acid sequences with increased stability in the bound peptide-EZH2 structure. These sequences were validated through the calculation of the fold specificity and approximate binding affinity of the designed peptides. Here we report the discovery of novel EZH2 inhibitory peptides using the de novo peptide design method. The computationally discovered peptides were experimentally validated in vitro using dose titrations and mechanism of action enzymatic assays. The peptide with the highest in vitro response, SQ037, was validated in nucleo using quantitative mass spectrometry-based proteomics. This peptide had an IC50 of 13.5 [Formula: see text]M, demonstrated greater potency as an inhibitor when compared to the native and K27A mutant control peptides, and demonstrated competitive inhibition versus the peptide substrate. Additionally, this peptide demonstrated high specificity to the EZH2 target in comparison to other histone methyltransferases. The validated peptides are the first computationally designed peptides that directly

  10. Cell growth and proteolytic activity of Lactobacillus acidophilus, Lactobacillus helveticus, Lactobacillus delbrueckii ssp. bulgaricus, and Streptococcus thermophilus in milk as affected by supplementation with peptide fractions.

    Science.gov (United States)

    Gandhi, Akanksha; Shah, Nagendra P

    2014-12-01

    The present investigation examined the effects of supplementation of milk peptide fractions produced by enzymatic hydrolysis on the fermentation of reconstituted skim milk (RSM). Changes in pH, cell growth, proteolytic activity, and angiotensin-converting enzyme (ACE)-inhibitory activity were monitored during fermentation of RSM by pure cultures of Lactobacillus acidophilus, Lactobacillus helveticus, Lactobacillus delbrueckii ssp. bulgaricus, and Streptococcus thermophilus. The study showed that supplementation with peptide fractions of different molecular weights did not significantly affect the bacterial growth in RSM. All bacteria showed an increased proteolytic activity in RSM supplemented with large peptides (>10 kDa), and L. helveticus in general exhibited the highest proteolytic activity among the bacteria studied. The ACE-inhibitory activity was observed to be the maximum in RSM supplemented with larger peptides (>10 kDa) for all bacteria. The results suggest that proteolysis by bacteria leads to increased production of ACE-inhibitory peptides compared to the supplemented peptides produced by enzymatic hydrolysis.

  11. Bioactive peptides released from Saccharomyces cerevisiae under accelerated autolysis in a wine model system.

    Science.gov (United States)

    Alcaide-Hidalgo, J M; Pueyo, E; Polo, M C; Martínez-Rodríguez, A J

    2007-09-01

    The ACE inhibitory activity (IACE) and the oxygen radical absorbance capacity (ORAC-FL) values of yeast peptides isolated from a model wine during accelerated autolysis of Saccharomyces cerevisiae have been studied. Samples were taken at 6, 24, 48, 121, and 144 h of autolysis. Peptide concentration increased throughout autolysis process. Peptides were fractionated into 2 fractions: F1, constituted by hydrophilic peptides, and F2, containing hydrophobic peptides. Both IACE activity and ORAC-FL values increased during 121 h of autolysis, then decreased afterward. Peptide fraction F2 was the main fraction involved in IACE activity and ORAC-FL.

  12. 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.

  13. A cancer specific cell-penetrating peptide, BR2, for the efficient delivery of an scFv into cancer cells.

    Directory of Open Access Journals (Sweden)

    Ki Jung Lim

    Full Text Available Cell-penetrating peptides (CPPs have proven very effective as intracellular delivery vehicles for various therapeutics. However, there are some concerns about non-specific penetration and cytotoxicity of CPPs for effective cancer treatments. Herein, based on the cell-penetrating motif of an anticancer peptide, buforin IIb, we designed several CPP derivatives with cancer cell specificity. Among the derivatives, a 17-amino acid peptide (BR2 was found to have cancer-specificity without toxicity to normal cells. After specifically targeting cancer cells through interaction with gangliosides, BR2 entered cells via lipid-mediated macropinocytosis. Moreover, BR2 showed higher membrane translocation efficiency than the well-known CPP Tat (49-57. The capability of BR2 as a cancer-specific drug carrier was demonstrated by fusion of BR2 to a single-chain variable fragment (scFv directed toward a mutated K-ras (G12V. BR2-fused scFv induced a higher degree of apoptosis than Tat-fused scFv in K-ras mutated HCT116 cells. These results suggest that the novel cell-penetrating peptide BR2 has great potential as a useful drug delivery carrier with cancer cell specificity.

  14. A cancer specific cell-penetrating peptide, BR2, for the efficient delivery of an scFv into cancer cells.

    Science.gov (United States)

    Lim, Ki Jung; Sung, Bong Hyun; Shin, Ju Ri; Lee, Young Woong; Kim, Da Jung; Yang, Kyung Seok; Kim, Sun Chang

    2013-01-01

    Cell-penetrating peptides (CPPs) have proven very effective as intracellular delivery vehicles for various therapeutics. However, there are some concerns about non-specific penetration and cytotoxicity of CPPs for effective cancer treatments. Herein, based on the cell-penetrating motif of an anticancer peptide, buforin IIb, we designed several CPP derivatives with cancer cell specificity. Among the derivatives, a 17-amino acid peptide (BR2) was found to have cancer-specificity without toxicity to normal cells. After specifically targeting cancer cells through interaction with gangliosides, BR2 entered cells via lipid-mediated macropinocytosis. Moreover, BR2 showed higher membrane translocation efficiency than the well-known CPP Tat (49-57). The capability of BR2 as a cancer-specific drug carrier was demonstrated by fusion of BR2 to a single-chain variable fragment (scFv) directed toward a mutated K-ras (G12V). BR2-fused scFv induced a higher degree of apoptosis than Tat-fused scFv in K-ras mutated HCT116 cells. These results suggest that the novel cell-penetrating peptide BR2 has great potential as a useful drug delivery carrier with cancer cell specificity.

  15. Molecular insights into the interaction between Plasmodium falciparum apical membrane antigen 1 and an invasion-inhibitory peptide.

    Directory of Open Access Journals (Sweden)

    Geqing Wang

    Full Text Available Apical membrane antigen 1 (AMA1 of the human malaria parasite Plasmodium falciparum has been implicated in invasion of the host erythrocyte. It interacts with malarial rhoptry neck (RON proteins in the moving junction that forms between the host cell and the invading parasite. Agents that block this interaction inhibit invasion and may serve as promising leads for anti-malarial drug development. The invasion-inhibitory peptide R1 binds to a hydrophobic cleft on AMA1, which is an attractive target site for small molecules that block parasite invasion. In this work, truncation and mutational analyses show that Phe5-Phe9, Phe12 and Arg15 in R1 are the most important residues for high affinity binding to AMA1. These residues interact with two well-defined binding hot spots on AMA1. Computational solvent mapping reveals that one of these hot spots is suitable for small molecule targeting. We also confirm that R1 in solution binds to AMA1 with 1:1 stoichiometry and adopts a secondary structure consistent with the major form of R1 observed in the crystal structure of the complex. Our results provide a basis for designing high affinity inhibitors of the AMA1-RON2 interaction.

  16. A role of TDIF peptide signaling in vascular cell differentiation is conserved among euphyllophytes

    Directory of Open Access Journals (Sweden)

    Yuki eHirakawa

    2015-11-01

    Full Text Available Peptide signals mediate a variety of cell-to-cell communication crucial for plant growth and development. During Arabidopsis thaliana vascular development, a CLE (CLAVATA3/EMBRYO SURROUNDING REGION-related family peptide hormone, TDIF (tracheary element differentiation inhibitory factor, regulates procambial cell fate by its inhibitory activity on xylem differentiation. To address if this activity is conserved among vascular plants, we performed comparative analyses of TDIF signaling in non-flowering vascular plants (gymnosperms, monilophytes and lycophytes. We identified orthologs of TDIF/CLE as well as its receptor TDR/PXY (TDIF RECEPTOR/PHLOEM INTERCALATED WITH XYLEM in Ginkgo biloba, Adiantum aethiopicum and Selaginella kraussiana by RACE-PCR. The predicted TDIF peptide sequences in seed plants and monilophytes were identical to that of A. thaliana TDIF. We examined the effects of exogenous CLE peptide-motif sequences of TDIF in these species. We found that liquid culturing of dissected leaves or shoots was useful for examining TDIF activity during vascular development. TDIF treatment suppressed xylem/tracheary element differentiation of procambial cells in G. bioloba and A. aethiopicum leaves. In contrast, neither TDIF nor putative endogenous TDIF inhibited xylem differentiation in developing shoots and rhizophores of S. kraussiana. These data suggest that activity of TDIF in vascular development is conserved among extant euphyllophytes. In addition to the conserved function, via liquid culturing of its bulbils, we found a novel inhibitory activity on root growth in the monilophyte Asplenium x lucrosum suggesting lineage-specific co-option of peptide signaling occurred during the evolution of vascular plant organs.

  17. Marine-Derived Bioactive Peptides with Pharmacological Activities- A Review

    Directory of Open Access Journals (Sweden)

    Sana Rabiei

    2017-10-01

    Full Text Available Some nutritional factors are related to chronic disease. In response to increased concern regarding nutrition and health, the functional and nutraceuticals food markets have been developed. During food digestion, proteins are hydrolyzed and a wide range of peptides are formed. Some of these peptides have special structures which permit them to confer particular biological functions. Marine animals which involve more than half of the world biological varieties are a wide source of bioactive proteins and peptides. Marine derived peptides show various physiologic functions such as anti-oxidant, antimicrobial, anti-cancer, Angiotensin1-Converting Enzyme (ACE glucosidase and a-amylase inhibitory effects in vitro. Before application of marine bioactive peptides as nutraceuticals or functional food ingredients, their efficacy should be approved through pre-clinical animal and then clinical studies. The aim of this study was to review the studies conducted on the pharmacological effect of marine bioactive peptides in animal models and humans.

  18. Mung bean proteins and peptides: nutritional, functional and bioactive properties

    Directory of Open Access Journals (Sweden)

    Zhu Yi-Shen

    2018-02-01

    Full Text Available To date, no extensive literature review exists regarding potential uses of mung bean proteins and peptides. As mung bean has long been widely used as a food source, early studies evaluated mung bean nutritional value against the Food and Agriculture Organization of the United Nations (FAO/the World Health Organization (WHO amino acids dietary recommendations. The comparison demonstrated mung bean to be a good protein source, except for deficiencies in sulphur-containing amino acids, methionine and cysteine. Methionine and cysteine residues have been introduced into the 8S globulin through protein engineering technology. Subsequently, purified mung bean proteins and peptides have facilitated the study of their structural and functional properties. Two main types of extraction methods have been reported for isolation of proteins and peptides from mung bean flours, permitting sequencing of major proteins present in mung bean, including albumins and globulins (notably 8S globulin. However, the sequence for albumin deposited in the UniProt database differs from other sequences reported in the literature. Meanwhile, a limited number of reports have revealed other useful bioactivities for proteins and hydrolysed peptides, including angiotensin-converting enzyme inhibitory activity, anti-fungal activity and trypsin inhibitory activity. Consequently, several mung bean hydrolysed peptides have served as effective food additives to prevent proteolysis during storage. Ultimately, further research will reveal other nutritional, functional and bioactive properties of mung bean for uses in diverse applications.

  19. 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.

  20. Capabilities of laser technology for manufacturing diagnostic peptide matrices with maximal density

    Energy Technology Data Exchange (ETDEWEB)

    Baum, O I; Shcherbakov, E M; Sobol' , E N [Institute on Laser and Information Technologies of the Russian Academy of Sciencies, Troitsk, Moscow (Russian Federation); Nesterov-Müller, A [Karlsruhe Institute of Technology, Institute of Microstructure Technology (Germany)

    2016-02-28

    The process of manufacturing a matrix-gel biochip is modelled by means of laser fused deposition of a layer of polymer microparticles, containing a sensitive peptide element, onto a glass substrate. The limits of acceptable ranges and the optimal values of laser parameters, at which the melting of the polymer coating occurs without damaging the sensitive elements of the biochip, are theoretically determined. The results of the experiments on laser fused deposition of a layer of microparticles having the size 3 – 4 μm confirm the conservation of the functions of the biological complexes at optimal irradiation regimes. The parameters of the laser impact affecting the possible minimal separation between the zones of laser fused deposition are investigated. The essential role of heat conductivity and thermoplasticity of the polymer in increasing the size of the melted droplet is demonstrated. Using the laser radiation with the wavelength 532 nm focused into a spot with the diameter 6 μm (the laser pulse duration being 10 ms) the laser fused deposition density of 110000 spots per 1 cm{sup 2} is achieved. The maximal estimated density of laser fused deposition for the studied system amounts to 250000 spots per 1 cm{sup 2}. (biophotonics)

  1. Cre Fused with RVG Peptide Mediates Targeted Genome Editing in Mouse Brain Cells In Vivo.

    Science.gov (United States)

    Zou, Zhiyuan; Sun, Zhaolin; Li, Pan; Feng, Tao; Wu, Sen

    2016-12-14

    Cell penetrating peptides (CPPs) are short peptides that can pass through cell membranes. CPPs can facilitate the cellular entry of proteins, macromolecules, nanoparticles and drugs. RVG peptide (RVG hereinafter) is a 29-amino-acid CPP derived from a rabies virus glycoprotein that can cross the blood-brain barrier (BBB) and enter brain cells. However, whether RVG can be used for genome editing in the brain has not been reported. In this work, we combined RVG with Cre recombinase for bacterial expression. The purified RVG-Cre protein cut plasmids in vitro and traversed cell membranes in cultured Neuro2a cells. By tail vein-injecting RVG-Cre into Cre reporter mouse lines mTmG and Rosa26 lacZ , we demonstrated that RVG-Cre could target brain cells and achieve targeted somatic genome editing in adult mice. This direct delivery of the gene-editing enzyme protein into mouse brains with RVG is much safer than plasmid- or viral-based methods, holding promise for further applications in the treatment of various brain diseases.

  2. 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....

  3. d-Amino acid mutation of PMI as potent dual peptide inhibitors of p53-MDM2/MDMX interactions.

    Science.gov (United States)

    Li, Xiang; Liu, Chao; Chen, Si; Hu, Honggang; Su, Jiacan; Zou, Yan

    2017-10-15

    According to the previously reported potent dual l-peptide PMI of p53-MDM2/MDMX interactions, a series of d-amino acid mutational PMI analogues, PMI-1-4, with enhanced proteolytic resistence and in vitro tumor cell inhibitory activities were reported, of which Liposome-PMI-1 showed a stronger inhibitory activity against the U87 cell lines than Nutlin-3. This d-amino acid mutation strategy may give a hand for enhancing the potential of peptide drugs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Regulation of the mesolimbic dopamine circuit by feeding peptides.

    Science.gov (United States)

    Liu, S; Borgland, S L

    2015-03-19

    Polypeptides produced in the gastrointestinal tract, stomach, adipocytes, pancreas and brain that influence food intake are referred to as 'feeding-related' peptides. Most peptides that influence feeding exert an inhibitory effect (anorexigenic peptides). In contrast, only a few exert a stimulating effect (orexigenic peptides), such as ghrelin. Homeostatic feeding refers to when food consumed matches energy deficits. However, in western society where access to palatable energy-dense food is nearly unlimited, food is mostly consumed for non-homeostatic reasons. Emerging evidence implicates the mesocorticolimbic circuitry, including dopamine neurons of the ventral tegmental area (VTA), as a key substrate for non-homeostatic feeding. VTA dopamine neurons encode cues that predict rewards and phasic release of dopamine in the ventral striatum motivates animals to forage for food. To elucidate how feeding-related peptides regulate reward pathways is of importance to reveal the mechanisms underlying non-homeostatic or hedonic feeding. Here, we review the current knowledge of how anorexigenic peptides and orexigenic peptides act within the VTA. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  5. Potential of acylated peptides to target the influenza A virus

    Directory of Open Access Journals (Sweden)

    Daniel Lauster

    2015-04-01

    Full Text Available For antiviral drug design, especially in the field of influenza virus research, potent multivalent inhibitors raise high expectations for combating epidemics and pandemics. Among a large variety of covalent and non-covalent scaffold systems for a multivalent display of inhibitors, we created a simple supramolecular platform to enhance the antiviral effect of our recently developed antiviral Peptide B (PeBGF, preventing binding of influenza virus to the host cell. By conjugating the peptide with stearic acid to create a higher-order structure with a multivalent display, we could significantly enhance the inhibitory effect against the serotypes of both human pathogenic influenza virus A/Aichi/2/1968 H3N2, and avian pathogenic A/FPV/Rostock/34 H7N1 in the hemagglutination inhibition assay. Further, the inhibitory potential of stearylated PeBGF (C18-PeBGF was investigated by infection inhibition assays, in which we achieved low micromolar inhibition constants against both viral strains. In addition, we compared C18-PeBGF to other published amphiphilic peptide inhibitors, such as the stearylated sugar receptor mimicking peptide (Matsubara et al. 2010, and the “Entry Blocker” (EB (Jones et al. 2006, with respect to their antiviral activity against infection by Influenza A Virus (IAV H3N2. However, while this strategy seems at a first glance promising, the native situation is quite different from our experimental model settings. First, we found a strong potential of those peptides to form large amyloid-like supramolecular assemblies. Second, in vivo, the large excess of cell surface membranes provides an unspecific target for the stearylated peptides. We show that acylated peptides insert into the lipid phase of such membranes. Eventually, our study reveals serious limitations of this type of self-assembling IAV inhibitors.

  6. Identification of the peptide derived from S1 domain that inhibits type I and type II feline infectious peritonitis virus infection.

    Science.gov (United States)

    Doki, Tomoyoshi; Takano, Tomomi; Koyama, Yusuke; Hohdatsu, Tsutomu

    2015-06-02

    Feline infectious peritonitis virus (FIPV) can cause a lethal disease in cats, feline infectious peritonitis (FIP). A therapeutic drug that is effective against FIP has not yet been developed. Peptides based on viral protein amino acid sequences have recently been attracting attention as new antiviral drugs. In the present study, we synthesized 30 overlapping peptides based on the amino acid sequence of the S1 domain of the type I FIPV strain KU-2 S protein, and investigated their inhibitory effects on FIPV infection. To evaluate the inhibitory effects on type I FIPV infection of these peptides, we investigated a method to increase the infection efficiency of poorly replicative type I FIPV. The efficiency of type I FIPV infection was increased by diluting the virus with medium containing a polycation. Of the 30 peptides, I-S1-8 (S461-S480), I-S1-9 (S471-S490), I-S1-10 (S481-S500), I-S1-16 (S541-S560), and I-S1-22 (S601-S620) significantly decreased the infectivity of FIPV strain KU-2 while I-S1-9 and I-S1-16 exhibited marked inhibitory effects on FIPV infection. The inhibitory effects on FIPV infection of these 2 peptides on other type I and type II FIPV strains, feline herpesvirus (FHV), and feline calicivirus (FCV) were also examined. These 2 peptides specifically inhibited type I and type II FIPV, but did FHV or FCV infection. In conclusion, the possibility of peptides derived from the S protein of type I FIPV strain KU-2 as anti-FIPV agents effective not only for type I, but also type II FIPV was demonstrated in vitro. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Review: evolution of GnIH and related peptides structure and function in the chordates.

    Science.gov (United States)

    Osugi, Tomohiro; Ubuka, Takayoshi; Tsutsui, Kazuyoshi

    2014-01-01

    Discovery of gonadotropin-inhibitory hormone (GnIH) in the Japanese quail in 2000 was the first to demonstrate the existence of a hypothalamic neuropeptide inhibiting gonadotropin release. We now know that GnIH regulates reproduction by inhibiting gonadotropin synthesis and release via action on the gonadotropin-releasing hormone (GnRH) system and the gonadotrope in various vertebrates. GnIH peptides identified in birds and mammals have a common LPXRF-amide (X = L or Q) motif at the C-terminus and inhibit pituitary gonadotropin secretion. However, the function and structure of GnIH peptides are diverse in fish. Goldfish GnIHs possessing a C-terminal LPXRF-amide motif have both stimulatory and inhibitory effects on gonadotropin synthesis or release. The C-terminal sequence of grass puffer and medaka GnIHs are MPQRF-amide. To investigate the evolutionary origin of GnIH and its ancestral structure and function, we searched for GnIH in agnathans, the most ancient lineage of vertebrates. We identified GnIH precursor gene and mature GnIH peptides with C-terminal QPQRF-amide or RPQRF-amide from the brain of sea lamprey. Lamprey GnIH fibers were in close proximity to GnRH-III neurons. Further, one of lamprey GnIHs stimulated the expression of lamprey GnRH-III peptide in the hypothalamus and gonadotropic hormone β mRNA expression in the pituitary. We further identified the ancestral form of GnIH, which had a C-terminal RPQRF-amide, and its receptors in amphioxus, the most basal chordate species. The amphioxus GnIH inhibited cAMP signaling in vitro. In sum, the original forms of GnIH may date back to the time of the emergence of early chordates. GnIH peptides may have had various C-terminal structures slightly different from LPXRF-amide in basal chordates, which had stimulatory and/or inhibitory functions on reproduction. The C-terminal LPXRF-amide structure and its inhibitory function on reproduction may be selected in later-evolved vertebrates, such as birds and mammals.

  8. EGFR tyrosine kinase inhibitory peptide attenuates Helicobacter pylori-mediated hyper-proliferation in AGS enteric epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Himaya, S.W.A. [Marine Bio-Process Research Center, Pukyong National University, Nam-Gu, Busan, 608-737 (Korea, Republic of); Dewapriya, Pradeep [Department of Chemistry, Pukyong National University, Nam-Gu, Busan, 608-737 (Korea, Republic of); Kim, Se-Kwon, E-mail: sknkim@pknu.ac.kr [Marine Bio-Process Research Center, Pukyong National University, Nam-Gu, Busan, 608-737 (Korea, Republic of); Department of Chemistry, Pukyong National University, Nam-Gu, Busan, 608-737 (Korea, Republic of)

    2013-06-15

    Helicobacter pylori infection is one of the most critical causes of stomach cancer. The current study was conducted to explore the protective effects of an isolated active peptide H-P-6 (Pro-Gln-Pro-Lys-Val-Leu-Asp-Ser) from microbial hydrolysates of Chlamydomonas sp. against H. pylori-induced carcinogenesis. The peptide H-P-6 has effectively suppressed H. pylori-induced hyper-proliferation and migration of gastric epithelial cells (AGS). However, the peptide did not inhibit the viability of the bacteria or invasion into AGS cells. Therefore, the effect of the peptide on regulating H. pylori-induced molecular signaling was investigated. The results indicated that H. pylori activates the EGFR tyrosine kinase signaling and nuclear translocation of the β-catenin. The EGFR activation has led to the up-regulation of PI3K/Akt signaling pathway. Moreover, the nuclear translocation levels of β-catenin were significantly increased as a result of Akt mediated down-regulation of GSK3/β protein levels in the cytoplasm. Both of these consequences have resulted in increased expression of cell survival and migration related genes such as c-Myc, cyclin-D, MMP-2 and matrilysin. Interestingly, the isolated peptide potently inhibited H. pylori-mediated EGFR activation and thereby down-regulated the subsequent P13K/Akt signaling leading to β-catenin nuclear translocation. The effect of the peptide was confirmed with the use of EGFR tyrosine kinase inhibitor AG1487 and molecular docking studies. Collectively this study identifies a potent peptide which regulates the H. pylori-induced hyper-proliferation and migration of AGS cells at molecular level. - Highlights: • Chlamydomonas sp. derived peptide H-P-6 inhibits H. pylori-induced pathogenesis. • H-P-6 suppresses H. pylori-induced hyper-proliferation and migration of AGS cells. • The peptide inhibits H. pylori-induced EGFR activation.

  9. Identification of natural antimicrobial agents to treat dengue infection: In vitro analysis of latarcin peptide activity against dengue virus.

    Science.gov (United States)

    Rothan, Hussin A; Bahrani, Hirbod; Rahman, Noorsaadah Abd; Yusof, Rohana

    2014-05-31

    Although there have been considerable advances in the study of dengue virus, no vaccines or anti-dengue drugs are currently available for humans. Therefore, new approaches are necessary for the development of potent anti-dengue drugs. Natural antimicrobial peptides (AMPs) with potent antiviral activities are potential hits-to-leads for antiviral drug discovery. We performed this study to identify and characterise the inhibitory potential of the latarcin peptide (Ltc 1, SMWSGMWRRKLKKLRNALKKKLKGE) against dengue virus replication in infected cells. The Ltc 1 peptide showed a significantly inhibitory effect against the dengue protease NS2B-NS3pro at 37°C, a physiological human temperature, (IC50, 12.68 ± 3.2 μM), and greater inhibitory effect was observed at 40°C, a temperature similar to a high fever (IC50, 6.58 ± 4.1 μM). A greater reduction in viral load (p.f.u./ml) was observed at simultaneous (0.7 ± 0.3 vs. 7.2 ± 0.5 control) and post-treatment (1.8 ± 0.7 vs. 6.8 ± 0.6 control) compared to the pre-treatment (4.5 ± 0.6 vs. 6.9 ± 0.5 control). Treatment with the Ltc 1 peptide reduced the viral RNA in a dose-dependent manner with EC50 values of 8.3 ± 1.2, 7.6 ± 2.7 and 6.8 ± 2.5 μM at 24, 48 and 72 h, respectively. The Ltc 1 peptide exhibited significant inhibitory effects against dengue NS2B-NS3pro and virus replication in the infected cells. Therefore, further investigation is necessary to develop the Ltc 1 peptide as a new anti-dengue therapeutic.

  10. 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.

  11. Comparative evaluation of fiber fuse models

    International Nuclear Information System (INIS)

    Davis, D.D.; Mettler, S.C.; DiGiovanni, D.J.

    1997-01-01

    A phenomenon which results in the catastrophic destruction of the guiding properties of an optical fiber has been observed at laser power densities on the order of 3 x 10 6 watts/cm 2 in the core. This phenomenon is characterized by the propagation of a bright visible light from the point of initiation toward the laser source. The term 'fiber fuse' has been used because of the similarity in appearance to a burning fuse. The fiber fuse has been shown to start when the end of the fiber is contacted. It has also been initiated spontaneously from mechanical splices. This paper reports experimental data gathered on the fiber fuse and discusses their relationship to proposed physical mechanisms

  12. Improved proteolytic stability and potent activity against Leishmania infantum trypanothione reductase of α/β-peptide foldamers conjugated to cell-penetrating peptides.

    Science.gov (United States)

    de Lucio, Héctor; Gamo, Ana María; Ruiz-Santaquiteria, Marta; de Castro, Sonia; Sánchez-Murcia, Pedro A; Toro, Miguel A; Gutiérrez, Kilian Jesús; Gago, Federico; Jiménez-Ruiz, Antonio; Camarasa, María-José; Velázquez, Sonsoles

    2017-11-10

    The objective of the current study was to enhance the proteolytic stability of peptide-based inhibitors that target critical protein-protein interactions at the dimerization interface of Leishmania infantum trypanothione reductase (Li-TryR) using a backbone modification strategy. To achieve this goal we carried out the synthesis, proteolytic stability studies and biological evaluation of a small library of α/β 3 -peptide foldamers of different length (from 9-mers to 13-mers) and different α→β substitution patterns related to prototype linear α-peptides. We show that several 13-residue α/β 3 -peptide foldamers retain inhibitory potency against the enzyme (in both activity and dimerization assays) while they are far less susceptible to proteolytic degradation than an analogous α-peptide. The strong dependence of the binding affinities for Li-TryR on the length of the α,β-peptides is supported by theoretical calculations on conformational ensembles of the resulting complexes. The conjugation of the most proteolytically stable α/β-peptide with oligoarginines results in a molecule with potent activity against L. infantum promastigotes and amastigotes. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  13. Fused Bead Analysis of Diogenite Meteorites

    Science.gov (United States)

    Mittlefehldt, D.W.; Beck, B.W.; McSween, H.Y.; Lee, C.T. A.

    2009-01-01

    Bulk rock chemistry is an essential dataset in meteoritics and planetary science [1]. A common method used to obtain the bulk chemistry of meteorites is ICP-MS. While the accuracy, precision and low detection limits of this process are advantageous [2], the sample size used for analysis (approx.70 mg) can be a problem in a field where small and finite samples are the norm. Fused bead analysis is another bulk rock analytical technique that has been used in meteoritics [3]. This technique involves forming a glass bead from 10 mg of sample and measuring its chemistry using a defocused beam on a microprobe. Though the ICP-MS has lower detection limits than the microprobe, the fused bead method destroys a much smaller sample of the meteorite. Fused bead analysis was initially designed for samples with near-eutectic compositions and low viscosities. Melts generated of this type homogenize at relatively low temperatures and produce primary melts near the sample s bulk composition [3]. The application of fused bead analysis to samples with noneutectic melt compositions has not been validated. The purpose of this study is to test if fused bead analysis can accurately determine the bulk rock chemistry of non-eutectic melt composition meteorites. To determine this, we conduct two examinations of the fused bead. First, we compare ICP-MS and fused bead results of the same samples using statistical analysis. Secondly, we inspect the beads for the presence of crystals and chemical heterogeneity. The presence of either of these would indicate incomplete melting and quenching of the bead.

  14. Activity of synthetic peptides against Chlamydia.

    Science.gov (United States)

    Donati, Manuela; Cenacchi, Giovanna; Biondi, Roberta; Papa, Valentina; Borel, Nicole; Vecchio Nepita, Edoardo; Magnino, Simone; Pasquinelli, Gianandrea; Levi, Aurora; Franco, Octavio L

    2017-11-01

    The in vitro activity of six synthetic peptides against 36 strains of Chlamydia from different origins was investigated. Clavanin MO (CMO) proved to be the most active peptide, reducing the inclusion number of all Chlamydia strains from eight different species tested by ≥50% at 10 µg mL -1 . Mastoparan L showed an equal activity against C. trachomatis, C. pneumoniae, C. suis, and C. muridarum, but did not exert any inhibitory effect against C. psittaci, C. pecorum, C. abortus, and C. avium even at 80 µg mL -1 . These data suggest that CMO could be a promising compound in the prevention and treatment of chlamydial infections. © 2017 Wiley Periodicals, Inc.

  15. BG-4, a novel anticancer peptide from bitter gourd (Momordica charantia), promotes apoptosis in human colon cancer cells

    Science.gov (United States)

    Momordica charantia is a perennial plant with reported health benefits. BG-4, a novel peptide from Momordica charantia, was isolated, purified and characterized. The trypsin inhibitory activity of BG-4 is 8.6 times higher than purified soybean trypsin inhibitor. The high trypsin inhibitory activity ...

  16. Cloning and heterologous expression of the antibiotic peptide (ABP) genes from Rhizopus oligosporus NBRC 8631.

    Science.gov (United States)

    Yamada, Osamu; Sakamoto, Kazutoshi; Tominaga, Mihoko; Nakayama, Tasuku; Koseki, Takuya; Fujita, Akiko; Akita, Osamu

    2005-03-01

    We carried out protein sequencing of purified Antibiotic Peptide (ABP), and cloned two genes encoding this peptide as abp1 and abp2, from Rhizopus oligosporus NBRC 8631. Both genes contain an almost identical 231-bp segment, with only 3 nucleotide substitutions, encoding a 77 amino acid peptide. The abp gene product comprises a 28 amino acid signal sequence and a 49 amino acid mature peptide. Northern blot analysis showed that at least one of the abp genes is transcribed in R. oligosporus NBRC 8631. A truncated form of abp1 encoding only the mature peptide was fused with the alpha-factor signal peptide and engineered for expression in Pichia pastoris SMD1168H. Culture broth of the recombinant Pichia displayed ABP activity against Bacillus subtilis NBRC 3335 after induction of heterologous gene expression. This result indicates that mature ABP formed the active structure without the aid of other factors from R. oligosporus, and was secreted.

  17. Interaction of amyloid inhibitor proteins with amyloid beta peptides: insight from molecular dynamics simulations.

    Directory of Open Access Journals (Sweden)

    Payel Das

    Full Text Available Knowledge of the detailed mechanism by which proteins such as human αB- crystallin and human lysozyme inhibit amyloid beta (Aβ peptide aggregation is crucial for designing treatment for Alzheimer's disease. Thus, unconstrained, atomistic molecular dynamics simulations in explicit solvent have been performed to characterize the Aβ17-42 assembly in presence of the αB-crystallin core domain and of lysozyme. Simulations reveal that both inhibitor proteins compete with inter-peptide interaction by binding to the peptides during the early stage of aggregation, which is consistent with their inhibitory action reported in experiments. However, the Aβ binding dynamics appear different for each inhibitor. The binding between crystallin and the peptide monomer, dominated by electrostatics, is relatively weak and transient due to the heterogeneous amino acid distribution of the inhibitor surface. The crystallin-bound Aβ oligomers are relatively long-lived, as they form more extensive contact surface with the inhibitor protein. In contrast, a high local density of arginines from lysozyme allows strong binding with Aβ peptide monomers, resulting in stable complexes. Our findings not only illustrate, in atomic detail, how the amyloid inhibitory mechanism of human αB-crystallin, a natural chaperone, is different from that of human lysozyme, but also may aid de novo design of amyloid inhibitors.

  18. Studies on lactoferricin-derived Escherichia coli membrane-active peptides reveal differences in the mechanism of N-acylated versus nonacylated peptides.

    Science.gov (United States)

    Zweytick, Dagmar; Deutsch, Günter; Andrä, Jörg; Blondelle, Sylvie E; Vollmer, Ekkehard; Jerala, Roman; Lohner, Karl

    2011-06-17

    To improve the low antimicrobial activity of LF11, an 11-mer peptide derived from human lactoferricin, mutant sequences were designed based on the defined structure of LF11 in the lipidic environment. Thus, deletion of noncharged polar residues and strengthening of the hydrophobic N-terminal part upon adding a bulky hydrophobic amino acid or N-acylation resulted in enhanced antimicrobial activity against Escherichia coli, which correlated with the peptides' degree of perturbation of bacterial membrane mimics. Nonacylated and N-acylated peptides exhibited different effects at a molecular level. Nonacylated peptides induced segregation of peptide-enriched and peptide-poor lipid domains in negatively charged bilayers, although N-acylated peptides formed small heterogeneous domains resulting in a higher degree of packing defects. Additionally, only N-acylated peptides perturbed the lateral packing of neutral lipids and exhibited increased permeability of E. coli lipid vesicles. The latter did not correlate with the extent of improvement of the antimicrobial activity, which could be explained by the fact that elevated binding of N-acylated peptides to lipopolysaccharides of the outer membrane of gram-negative bacteria seems to counteract the elevated membrane permeabilization, reflected in the respective minimal inhibitory concentration for E. coli. The antimicrobial activity of the peptides correlated with an increase of membrane curvature stress and hence bilayer instability. Transmission electron microscopy revealed that only the N-acylated peptides induced tubular protrusions from the outer membrane, whereas all peptides caused detachment of the outer and inner membrane of E. coli bacteria. Viability tests demonstrated that these bacteria were dead before onset of visible cell lysis.

  19. Studies on Lactoferricin-derived Escherichia coli Membrane-active Peptides Reveal Differences in the Mechanism of N-Acylated Versus Nonacylated Peptides*

    Science.gov (United States)

    Zweytick, Dagmar; Deutsch, Günter; Andrä, Jörg; Blondelle, Sylvie E.; Vollmer, Ekkehard; Jerala, Roman; Lohner, Karl

    2011-01-01

    To improve the low antimicrobial activity of LF11, an 11-mer peptide derived from human lactoferricin, mutant sequences were designed based on the defined structure of LF11 in the lipidic environment. Thus, deletion of noncharged polar residues and strengthening of the hydrophobic N-terminal part upon adding a bulky hydrophobic amino acid or N-acylation resulted in enhanced antimicrobial activity against Escherichia coli, which correlated with the peptides' degree of perturbation of bacterial membrane mimics. Nonacylated and N-acylated peptides exhibited different effects at a molecular level. Nonacylated peptides induced segregation of peptide-enriched and peptide-poor lipid domains in negatively charged bilayers, although N-acylated peptides formed small heterogeneous domains resulting in a higher degree of packing defects. Additionally, only N-acylated peptides perturbed the lateral packing of neutral lipids and exhibited increased permeability of E. coli lipid vesicles. The latter did not correlate with the extent of improvement of the antimicrobial activity, which could be explained by the fact that elevated binding of N-acylated peptides to lipopolysaccharides of the outer membrane of Gram-negative bacteria seems to counteract the elevated membrane permeabilization, reflected in the respective minimal inhibitory concentration for E. coli. The antimicrobial activity of the peptides correlated with an increase of membrane curvature stress and hence bilayer instability. Transmission electron microscopy revealed that only the N-acylated peptides induced tubular protrusions from the outer membrane, whereas all peptides caused detachment of the outer and inner membrane of E. coli bacteria. Viability tests demonstrated that these bacteria were dead before onset of visible cell lysis. PMID:21515687

  20. Signal peptide of eosinophil cationic protein is toxic to cells lacking signal peptide peptidase

    International Nuclear Information System (INIS)

    Wu, C.-M.; Chang, Margaret Dah-Tsyr

    2004-01-01

    Eosinophil cationic protein (ECP) is a toxin secreted by activated human eosinophils. The properties of mature ECP have been well studied but those of the signal peptide of ECP (ECPsp) are not clear. In this study, several chimeric proteins containing N-terminal fusion of ECPsp were generated, and introduced into Escherichia coli, Pichia pastoris, and human epidermoid carcinoma cell line A431 to study the function of ECPsp. We found that expression of ECPsp chimeric proteins inhibited the growth of E. coli and P. pastoris but not A431 cells. Primary sequence analysis and in vitro transcription/translation of ECPsp have revealed that it is a potential substrate for human signal peptide peptidase (hSPP), an intramembrane protease located in endoplasmic reticulum. In addition, knockdown of the hSPP mRNA expression in ECPsp-eGFP/A431 cells caused the growth inhibitory effect, whereas complementally expression of hSPP in P. pastoris system rescued the cell growth. Taken together, we have demonstrated that ECPsp is a toxic signal peptide, and expression of hSPP protects the cells from growth inhibition

  1. Use of low fusing alloy in dentistry.

    Science.gov (United States)

    Wee, A G; Schneider, R L; Aquilino, S A

    1998-11-01

    Low fusing alloy has been used in dentistry for remount procedures in both fixed and removable prosthodontics, in implant prosthodontics for the fabrication of solid implant casts, in maxillofacial prosthetics as oral radiation shields, and in dental research for its unique properties. Previously, the use of low fusing alloy was thought to offer a high degree of dimensional accuracy. However, multiple in vitro studies have shown that its presumed dimensional accuracy may be questionable. This article reviews the physical properties, metallurgical considerations of low fusing alloy, its applications in dentistry, and a safe, simple method of using low fusing alloy.

  2. Cell wall trapping of autocrine peptides for human G-protein-coupled receptors on the yeast cell surface.

    Directory of Open Access Journals (Sweden)

    Jun Ishii

    Full Text Available G-protein-coupled receptors (GPCRs regulate a wide variety of physiological processes and are important pharmaceutical targets for drug discovery. Here, we describe a unique concept based on yeast cell-surface display technology to selectively track eligible peptides with agonistic activity for human GPCRs (Cell Wall Trapping of Autocrine Peptides (CWTrAP strategy. In our strategy, individual recombinant yeast cells are able to report autocrine-positive activity for human GPCRs by expressing a candidate peptide fused to an anchoring motif. Following expression and activation, yeast cells trap autocrine peptides onto their cell walls. Because captured peptides are incapable of diffusion, they have no impact on surrounding yeast cells that express the target human GPCR and non-signaling peptides. Therefore, individual yeast cells can assemble the autonomous signaling complex and allow single-cell screening of a yeast population. Our strategy may be applied to identify eligible peptides with agonistic activity for target human GPCRs.

  3. Intervention with Serine Protease Activity with Small Peptides

    DEFF Research Database (Denmark)

    Xu, Peng

    2015-01-01

    Serine proteases perform proteolytic reactions in many physiological and metabolic processes and have been certified as targets for therapeutics. Small peptides can be used as potent antagonists to target serine proteases and intervene with their activities. Urokinase-type plasminogen activator (u......PA) plays an important role in plasminogen activation system, which has many physiological and pathological functions and is closely associated with the metastasis of tumor cells. Based on a mono-cyclic peptidic inhibitor of murine uPA (muPA), mupain-1, which was screened out from a phage-display library...... before, we elucidated the binding and inhibitory mechanism by using multiple techniques, like X-ray crystallography, site-directed mutagenesis, isothermal titration calorimetry and surface plasmon resonance analysis. By studying the peptide-enzyme interaction, we discovered an unusual inhibitor...

  4. Induced resistance to the antimicrobial peptide lactoferricin B in Staphylococcus aureus.

    Science.gov (United States)

    Samuelsen, Orjan; Haukland, Hanne H; Jenssen, Håvard; Krämer, Manuela; Sandvik, Kjersti; Ulvatne, Hilde; Vorland, Lars H

    2005-06-20

    This study was designed to investigate inducible intrinsic resistance against lactoferricin B in Staphylococcus aureus. Serial passage of seven S. aureus strains in medium with increasing concentrations of peptide resulted in an induced resistance at various levels in all strains. The induced resistance was unstable and decreased relatively rapidly during passages in peptide free medium but the minimum inhibitory concentration remained elevated after thirty passages. Cross-resistance to penicillin G and low-level cross-resistance to the antimicrobial peptides indolicidin and Ala(8,13,18)-magainin-II amide [corrected] was observed. No cross-resistance was observed to the human cathelicidin LL-37. In conclusion, this study shows that S. aureus has intrinsic resistance mechanisms against antimicrobial peptides that can be induced upon exposure, and that this may confer low-level cross-resistance to other antimicrobial peptides.

  5. A Radiographic Study of Fused and Geminated Tooth

    Energy Technology Data Exchange (ETDEWEB)

    Park, Chul Jae; Lee, Sang Rae [Dept. of Oral Radiology, College of Dentistry, Kyunhee University, Seoul (Korea, Republic of)

    1990-02-15

    The incidence and several characteristic features of fused and geminated teeth were studied radiographically, with full mouth periapical radiogram and pantomogram, in 4201 patients of mixed dentition and 5358 patients of permanent dentition. The obtained results were as follows: 1. The prevalence was revealed to 2.86%, 0.32%, 0.33%, and 0.06% in deciduous fused tooth, permanent fused tooth, deciduous geminated tooth and permanent geminated tooth respectively, and these anomalies were occurred in female more than male. 2. Fused teeth were observed predominantly in lower anterior teeth area, especially in lateral incisor and canine region, and many cases of deciduous geminated tooth were observed in upper central incisor region. 3. Congenital missing rates of succedaneous tooth in deciduous fused teeth were 57.1%, 85.7%, 71.0%, 69.0% in upper right and left central-lateral incisor regions, lower right and left lateral incisor-canine regions, respectively. 4. Prevalence of dental caries was 42.3%, 18.8% and 5.6% in deciduous fused, deciduous geminated and permanent fused tooth, respectively. 5. In classifying of fused and geminated teeth into 9 type, by following appearance such as number of crown, root, pulp chamber and pulp canal of those teeth, it was more favorable that Type I (2 crown, 2 root, 2 pulp chamber, 2 pulp canal) in deciduous fused tooth and Type IX (1 crown, 1 root, 1 pulp chamber, 1 pulp canal) in permanent used tooth, deciduous and permanent geminated tooth.

  6. A Radiographic Study of Fused and Geminated Tooth

    International Nuclear Information System (INIS)

    Park, Chul Jae; Lee, Sang Rae

    1990-01-01

    The incidence and several characteristic features of fused and geminated teeth were studied radiographically, with full mouth periapical radiogram and pantomogram, in 4201 patients of mixed dentition and 5358 patients of permanent dentition. The obtained results were as follows: 1. The prevalence was revealed to 2.86%, 0.32%, 0.33%, and 0.06% in deciduous fused tooth, permanent fused tooth, deciduous geminated tooth and permanent geminated tooth respectively, and these anomalies were occurred in female more than male. 2. Fused teeth were observed predominantly in lower anterior teeth area, especially in lateral incisor and canine region, and many cases of deciduous geminated tooth were observed in upper central incisor region. 3. Congenital missing rates of succedaneous tooth in deciduous fused teeth were 57.1%, 85.7%, 71.0%, 69.0% in upper right and left central-lateral incisor regions, lower right and left lateral incisor-canine regions, respectively. 4. Prevalence of dental caries was 42.3%, 18.8% and 5.6% in deciduous fused, deciduous geminated and permanent fused tooth, respectively. 5. In classifying of fused and geminated teeth into 9 type, by following appearance such as number of crown, root, pulp chamber and pulp canal of those teeth, it was more favorable that Type I (2 crown, 2 root, 2 pulp chamber, 2 pulp canal) in deciduous fused tooth and Type IX (1 crown, 1 root, 1 pulp chamber, 1 pulp canal) in permanent used tooth, deciduous and permanent geminated tooth.

  7. Additive manufacturing of transparent fused quartz

    Science.gov (United States)

    Luo, Junjie; Hostetler, John M.; Gilbert, Luke; Goldstein, Jonathan T.; Urbas, Augustine M.; Bristow, Douglas A.; Landers, Robert G.; Kinzel, Edward C.

    2018-04-01

    This paper investigates a filament-fed process for additive manufacturing (AM) of fused quartz. Glasses such as fused quartz have significant scientific and engineering applications, which include optics, communications, electronics, and hermetic seals. AM has several attractive benefits such as increased design freedom, faster prototyping, and lower processing costs for small production volumes. However, current research into glass AM has focused primarily on nonoptical applications. Fused quartz is studied here because of its desirability for use in high-quality optics due to its high transmissivity and thermal stability. Fused quartz filaments are fed into a CO2 laser-generated molten region, smoothly depositing material onto the workpiece. Spectroscopy and pyrometry are used to measure the thermal radiation incandescently emitted from the molten region. The effects of the laser power and scan speed are determined by measuring the morphology of single tracks. Thin walls are printed to study the effects of layer-to-layer height. This information is used to deposit solid pieces including a cylindrical-convex shape capable of focusing visible light. The transmittance and index homogeneity of the printed fused quartz are measured. These results show that the filament-fed process has the potential to print transmissive optics.

  8. New potentially antihypertensive peptides liberated in milk during fermentation with selected lactic acid bacteria and kombucha cultures.

    Science.gov (United States)

    Elkhtab, Ebrahim; El-Alfy, Mohamed; Shenana, Mohamed; Mohamed, Abdelaty; Yousef, Ahmed E

    2017-12-01

    Compounds with the ability to inhibit angiotensin-converting enzyme (ACE) are used medically to treat human hypertension. The presence of such compounds naturally in food is potentially useful for treating the disease state. The goal of this study was to screen lactic acid bacteria, including species commonly used as dairy starter cultures, for the ability to produce new potent ACE-inhibiting peptides during milk fermentation. Strains of Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus helveticus, Lactobacillus paracasei, Lactococcus lactis, Leuconostoc mesenteroides, and Pediococcus acidilactici were tested in this study. Additionally, a symbiotic consortium of yeast and bacteria, used commercially to produce kombucha tea, was tested. Commercially sterile milk was inoculated with lactic acid bacteria strains and kombucha culture and incubated at 37°C for up to 72 h, and the liberation of ACE-inhibiting compounds during fermentation was monitored. Fermented milk was centrifuged and the supernatant (crude extract) was subjected to ultrafiltration using 3- and 10-kDa cut-off filters. Crude and ultrafiltered extracts were tested for ACE-inhibitory activity. The 10-kDa filtrate resulting from L. casei ATCC 7469 and kombucha culture fermentations (72 h) showed the highest ACE-inhibitory activity. Two-step purification of these filtrates was done using HPLC equipped with a reverse-phase column. Analysis of HPLC-purified fractions by liquid chromatography-mass spectrometry/mass spectrometry identified several new peptides with potent ACE-inhibitory activities. Some of these peptides were synthesized, and their ACE-inhibitory activities were confirmed. Use of organisms producing these unique peptides in food fermentations could contribute positively to human health. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  9. Porphyrins Fused with Unactivated Polycyclic Aromatic Hydrocarbons

    KAUST Repository

    Diev, Vyacheslav V.; Schlenker, Cody W.; Hanson, Kenneth; Zhong, Qiwen; Zimmerman, Jeramy D.; Forrest, Stephen R.; Thompson, Mark E.

    2012-01-01

    A systematic study of the preparation of porphyrins with extended conjugation by meso,β-fusion with polycyclic aromatic hydrocarbons (PAHs) is reported. The meso-positions of 5,15-unsubstituted porphyrins were readily functionalized with PAHs. Ring fusion using standard Scholl reaction conditions (FeCl 3, dichloromethane) occurs for perylene-substituted porphyrins to give a porphyrin β,meso annulated with perylene rings (0.7:1 ratio of syn and anti isomers). The naphthalene, pyrene, and coronene derivatives do not react under Scholl conditions but are fused using thermal cyclodehydrogenation at high temperatures, giving mixtures of syn and anti isomers of the meso,β-fused porphyrins. For pyrenyl-substituted porphyrins, a thermal method gives synthetically acceptable yields (>30%). Absorption spectra of the fused porphyrins undergo a progressive bathochromic shift in a series of naphthyl (λ max = 730 nm), coronenyl (λ max = 780 nm), pyrenyl (λ max = 815 nm), and perylenyl (λ max = 900 nm) annulated porphyrins. Despite being conjugated with unsubstituted fused PAHs, the β,meso-fused porphyrins are more soluble and processable than the parent nonfused precursors. Pyrenyl-fused porphyrins exhibit strong fluorescence in the near-infrared (NIR) spectral region, with a progressive improvement in luminescent efficiency (up to 13% with λ max = 829 nm) with increasing degree of fusion. Fused pyrenyl-porphyrins have been used as broadband absorption donor materials in photovoltaic cells, leading to devices that show comparatively high photovoltaic efficiencies. © 2011 American Chemical Society.

  10. Porphyrins Fused with Unactivated Polycyclic Aromatic Hydrocarbons

    KAUST Repository

    Diev, Vyacheslav V.

    2012-01-06

    A systematic study of the preparation of porphyrins with extended conjugation by meso,β-fusion with polycyclic aromatic hydrocarbons (PAHs) is reported. The meso-positions of 5,15-unsubstituted porphyrins were readily functionalized with PAHs. Ring fusion using standard Scholl reaction conditions (FeCl 3, dichloromethane) occurs for perylene-substituted porphyrins to give a porphyrin β,meso annulated with perylene rings (0.7:1 ratio of syn and anti isomers). The naphthalene, pyrene, and coronene derivatives do not react under Scholl conditions but are fused using thermal cyclodehydrogenation at high temperatures, giving mixtures of syn and anti isomers of the meso,β-fused porphyrins. For pyrenyl-substituted porphyrins, a thermal method gives synthetically acceptable yields (>30%). Absorption spectra of the fused porphyrins undergo a progressive bathochromic shift in a series of naphthyl (λ max = 730 nm), coronenyl (λ max = 780 nm), pyrenyl (λ max = 815 nm), and perylenyl (λ max = 900 nm) annulated porphyrins. Despite being conjugated with unsubstituted fused PAHs, the β,meso-fused porphyrins are more soluble and processable than the parent nonfused precursors. Pyrenyl-fused porphyrins exhibit strong fluorescence in the near-infrared (NIR) spectral region, with a progressive improvement in luminescent efficiency (up to 13% with λ max = 829 nm) with increasing degree of fusion. Fused pyrenyl-porphyrins have been used as broadband absorption donor materials in photovoltaic cells, leading to devices that show comparatively high photovoltaic efficiencies. © 2011 American Chemical Society.

  11. Antibacterial Effects of a Cell-Penetrating Peptide Isolated from Kefir.

    Science.gov (United States)

    Miao, Jianyin; Guo, Haoxian; Chen, Feilong; Zhao, Lichao; He, Liping; Ou, Yangwen; Huang, Manman; Zhang, Yi; Guo, Baoyan; Cao, Yong; Huang, Qingrong

    2016-04-27

    Kefir is a traditional fermented milk beverage used throughout the world for centuries. A cell-penetrating peptide, F3, was isolated from kefir by Sephadex G-50 gel filtration, DEAE-52 ion exchange, and reverse-phase high-performance liquid chromatography. F3 was determined to be a low molecular weight peptide containing one leucine and one tyrosine with two phosphate radicals. This peptide displayed antimicrobial activity across a broad spectrum of organisms including several Gram-positive and Gram-negative bacteria as well as fungi, with minimal inhibitory concentration (MIC) values ranging from 125 to 500 μg/mL. Cellular penetration and accumulation of F3 were determined by confocal laser scanning microscopy. The peptide was able to penetrate the cellular membrane of Escherichia coli and Staphylococcus aureus. Changes in cell morphology were observed by scanning electron microscopy (SEM). The results indicate that peptide F3 may be a good candidate for use as an effective biological preservative in agriculture and the food industry.

  12. Potential role of an antimicrobial peptide, KLK in inhibiting lipopolysaccharide-induced macrophage inflammation.

    Directory of Open Access Journals (Sweden)

    Pornpimon Jantaruk

    Full Text Available Antimicrobial peptides (AMPs are attractive alternatives to antibiotics. Due to their immune modulatory properties, AMPs are at present emerging as promising agents for controlling inflammatory-mediated diseases. In this study, anti-inflammatory potential of an antimicrobial peptide, KLK (KLKLLLLLKLK and its analogs was evaluated in lipopolysaccharide (LPS-induced RAW 264.7 macrophages. The results herein demonstrated that KLK peptide as well as its analogs significantly inhibited the pro-inflammatory mediator nitric oxide (NO, interleukin-1β (IL-1β and tumor necrosis factor-α (TNF-α production in LPS-stimulated RAW 264.7 macrophages in dose-dependent manners, and such inhibitory effects were not due to direct cytotoxicity. When considering inhibition potency, KLK among the test peptides exhibited the most effective activity. The inhibitory activity of KLK peptide also extended to include suppression of LPS-induced production of prostaglandin E2 (PGE2. KLK significantly decreased mRNA and protein expression of inducible nitric oxide synthase (iNOS and cyclooxygenase-2 (COX-2 as well as mRNA expression of IL-1β and TNF-α. Moreover, KLK inhibited nuclear translocation of nuclear factor-κB (NF-κB p65 and blocked degradation and phosphorylation of inhibitor of κB (IκB. Taken together, these results suggested that the KLK peptide inhibited inflammatory response through the down-regulation of NF-κB mediated activation in macrophages. Since peptide analogs with different amino acid sequences and arrangement were investigated for their anti-inflammatory activities, the residues/structures required for activity were also discussed. Our findings therefore proved anti-inflammatory potential of the KLK peptide and provide direct evidence for therapeutic application of KLK as a novel anti-inflammatory agent.

  13. Antibacterial and antiproliferative peptides in synbiotic yogurt-Release and stability during refrigerated storage.

    Science.gov (United States)

    Sah, B N P; Vasiljevic, T; McKechnie, S; Donkor, O N

    2016-06-01

    The search for alternative therapeutics is on the rise due to the extensive increase in bacterial resistance to various conventional antibiotics and side effects of conventional cancer therapies. Bioactive peptides released from natural sources such as dairy foods by lactic acid bacteria have received attention as a potential source of biotherapeutic peptides. However, liberation of peptides in yogurt depends on proteolytic activities of the cultures used. Thus, this research was conducted to establish generation of inhibitory peptides in yogurt against pathogenic bacteria and cancer cells during storage at 4°C for 28d. Water-soluble crude peptide extracts were prepared by high-speed centrifugation of plain and probiotic yogurts supplemented with or without pineapple peel powder (PPP). The inhibition zones against Escherichia coli and Staphylococcus aureus by PPP-fortified probiotic yogurt at 28d of storage were, respectively, 25.89 and 11.72mm in diameter, significantly higher than that of nonsupplemented control yogurts. Antiproliferative activity against HT29 colon cancer cells was also significantly higher in probiotic yogurt with PPP than in nonsupplemented probiotic yogurt. Overall, crude water-soluble peptide extracts of the probiotic yogurt with PPP possessed stronger inhibitory activities against bacteria and cancer cells than controls, and these activities were maintained during storage. However, activities were lowered substantially during in vitro gastrointestinal digestion. These findings support the possibility of utilizing dairy-derived bioactive peptides in the development of a superior alternative to the current generation of antibacterial and anticancer agents, as well as a functional ingredient in foods, nutraceuticals, and pharmaceuticals. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  14. Active peptides from skate (Okamejei kenojei) skin gelatin diminish angiotensin-I converting enzyme activity and intracellular free radical-mediated oxidation.

    Science.gov (United States)

    Ngo, Dai-Hung; Ryu, BoMi; Kim, Se-Kwon

    2014-01-15

    Skin gelatin of skate (Okamejei kenojei) was hydrolyzed using Alcalase, flavourzyme, Neutrase and protamex. It was found that the Alcalase hydrolysate exhibited the highest angiotensin-I converting enzyme (ACE) inhibitory activity. Then, Alcalase hydrolysate was further hydrolyzed with protease and separated by an ultrafiltration membrane system. Finally, two peptides responsible for ACE inhibitory activity were identified to be MVGSAPGVL (829Da) and LGPLGHQ (720Da), with IC50 values of 3.09 and 4.22μM, respectively. Moreover, the free radical-scavenging activity of the purified peptides was determined in human endothelial cells. In addition, the antioxidative mechanism of the purified peptides was evaluated by protein and gene expression levels of antioxidant enzymes. The current study demonstrated that the peptides derived from skate skin gelatin could be used in the food industry as functional ingredients with potent antihypertensive and antioxidant benefits. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Novel cyclo-peptides inhibit Ebola pseudotyped virus entry by targeting primed GP protein.

    Science.gov (United States)

    Li, Quanjie; Ma, Ling; Yi, Dongrong; Wang, Han; Wang, Jing; Zhang, Yongxin; Guo, Ying; Li, Xiaoyu; Zhou, Jinming; Shi, Yi; Gao, George F; Cen, Shan

    2018-07-01

    Ebola virus (EBOV) causes fatal hemorrhagic fever with high death rates in human. Currently, there are no available clinically-approved prophylactic or therapeutic treatments. The recently solved crystal structure of cleavage-primed EBOV glycoprotein (GPcl) in complex with the C domain of endosomal protein Niemann-Pick C1 (NPC1) provides a new target for the development of EBOV entry inhibitors. In this work, a computational approach using docking and molecular dynamic simulations is carried out for the rational design of peptide inhibitors. A novel cyclo-peptide (Pep-3.3) was identified to target at the late stage of EBOV entry and exhibit specific inhibitory activity against EBOV-GP pseudotyped viruses, with 50% inhibitory concentration (IC50) of 5.1 μM. In vitro binding assay and molecular simulations revealed that Pep-3.3 binds to GPcl with a KD value of 69.7 μM, through interacting with predicted residues in the hydrophobic binding pocket of GPcl. Mutation of predicted residues T83 caused resistance to Pep-3.3 inhibition in viral infectivity, providing preliminary support for the model of the peptide binding to GPcl. This study demonstrates the feasibility of inhibiting EBOV entry by targeting GPcl with peptides. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. SINA: A test system for proximity fuses

    Science.gov (United States)

    Ruizenaar, M. G. A.

    1989-04-01

    SINA, a signal generator that can be used for testing proximity fuses, is described. The circuitry of proximity fuses is presented; the output signal of the RF circuit results from a mixing of the emitted signal and received signal that is Doppler shifted in frequency by the relative motion of the fuse with respect to the reflecting target of surface. With SINA, digitized and stored target and clutter signals (previously measured) can be transformed to Doppler signals, for example during a real flight. SINA can be used for testing fuse circuitry, for example in the verification of results of computer simulations of the low frequency Doppler signal processing. The software of SINA and its use are explained.

  17. 30 CFR 57.12036 - Fuse removal or replacement.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fuse removal or replacement. 57.12036 Section 57.12036 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Electricity Surface and Underground § 57.12036 Fuse removal or replacement. Fuses shall not be removed or...

  18. Antioxidant and Anti-Inflammatory Activities of Hydrolysates and Peptide Fractions Obtained by Enzymatic Hydrolysis of Selected Heat-Treated Edible Insects.

    Science.gov (United States)

    Zielińska, Ewelina; Baraniak, Barbara; Karaś, Monika

    2017-09-02

    This study investigated the effect of heat treatment of edible insects on antioxidant and anti-inflammatory activities of peptides obtained by in vitro gastrointestinal digestion and absorption process thereof. The antioxidant potential of edible insect hydrolysates was determined as free radical-scavenging activity, ion chelating activity, and reducing power, whereas the anti-inflammatory activity was expressed as lipoxygenase and cyclooxygenase-2 inhibitory activity. The highest antiradical activity against DPPH • (2,2-diphenyl-1-picrylhydrazyl radical) was noted for a peptide fraction from baked cricket Gryllodes sigillatus hydrolysate (IC 50 value 10.9 µg/mL) and that against ABTS •+ (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical) was the highest for raw mealworm Tenebrio molitor hydrolysate (inhibitory concentration (IC 50 value) 5.3 µg/mL). The peptides obtained from boiled locust Schistocerca gregaria hydrolysate showed the highest Fe 2+ chelation ability (IC 50 value 2.57 µg/mL); furthermore, the highest reducing power was observed for raw G. sigillatus hydrolysate (0.771). The peptide fraction from a protein preparation from the locust S. gregaria exhibited the most significant lipoxygenase and cyclooxygenase-2 inhibitory activity (IC 50 value 3.13 µg/mL and 5.05 µg/mL, respectively).

  19. Generating User Interfaces with the FUSE-System

    OpenAIRE

    Frank Lonczewski; Siegfried Schreiber

    2017-01-01

    With the FUSE(Formal User interface Specification Environment)-System we present a methodology and a set of integrated tools for the automatic generation of graphical user interfaces. FUSE provides tool-based support for all phases (task-, user-, problem domain analysis, design of the logical user interface, design of user interface in a particular layout style) of the user interface development process. Based on a formal specification of dialogue- and layout guidelines, FUSE allows the autom...

  20. Investigation of fused silica dynamic behaviour

    International Nuclear Information System (INIS)

    Malaise, F.; Chevalier, J.M.; Bertron, I.; Malka, F.

    2006-01-01

    The survivability of the fused silica shields to shrapnel impacts is a key factor for the affordable operation of the intense laser irradiation future facility Laser Mega Joule (LMJ). This paper presents experimental data and computational modelling for LMJ fused silica upon shock wave loading and unloading. Gas-gun flyer plate impact and explosively driven tests have been conducted to investigate the dynamic behaviour of this material. Hugoniot states and the Hugoniot Elastic Limit of LMJ fused silica have been obtained. These experimental data are useful for determining some constitutive model constants of the 'Crack-Model', a continuum tensile and compressive failure model with friction based. This model has been improved by taking into account nonlinear elasticity. The numerical results obtained by performing computations of the previous tests and some ballistic impact tests are discussed. The numerical comparisons with the experimental data show good agreement. Further developments to simulate the permanent densification and the solid-to-solid phase transformation of fused silica are required. (authors)

  1. 30 CFR 56.12036 - Fuse removal or replacement.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fuse removal or replacement. 56.12036 Section 56.12036 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... § 56.12036 Fuse removal or replacement. Fuses shall not be removed or replaced by hand in an energized...

  2. 30 CFR 57.6502 - Safety fuse.

    Science.gov (United States)

    2010-07-01

    ... blasthole detonates. (d) Fuse shall be cut and capped in dry locations. (e) Blasting caps shall be crimped... the primer and the explosive material are securely in place. (g) Safety fuse shall be ignited only... to be fired, electric initiation systems, igniter cord and connectors, or other nonelectric...

  3. 30 CFR 56.6502 - Safety fuse.

    Science.gov (United States)

    2010-07-01

    ... be cut and capped in dry locations. (e) Blasting caps shall be crimped to fuse only with implements... material are securely in place. (g) Safety fuse shall be ignited only with devices designed for that... initiation systems, igniter cord and connectors, or other nonelectric initiation systems shall be used...

  4. Selectivity in the potentiation of antibacterial activity of α-peptide/β-peptoid peptidomimetics and antimicrobial peptides by human blood plasma

    DEFF Research Database (Denmark)

    Hein-Kristensen, Line; Knapp, Kolja M.; Franzyk, Henrik

    2013-01-01

    Antimicrobial peptides (AMPs) are promising leads for novel antibiotics; however, their activity is often compromised under physiological conditions. The purpose of this study was to determine the activity of alpha-peptide/beta-peptoid peptidomimetics and AMPs against Escherichia coli and Staphyl......Antimicrobial peptides (AMPs) are promising leads for novel antibiotics; however, their activity is often compromised under physiological conditions. The purpose of this study was to determine the activity of alpha-peptide/beta-peptoid peptidomimetics and AMPs against Escherichia coli...... and Staphylococcus aureus in the presence of human blood-derived matrices and immune effectors. The minimum inhibitory concentration (MIC) of two peptidomimetics against E. coli decreased by up to one order of magnitude when determined in 50% blood plasma as compared to MHB media. The MIC of a membrane-active AMP......, LL-I/3, also decreased, whereas two intracellularly acting AMPs were not potentiated by plasma. Blood serum had no effect on activity against E. coli and neither matrix had an effect on activity against S. aureus. Unexpectedly, physiological concentrations of human serum albumin did not influence...

  5. Negative regulation of RIG-I-mediated antiviral signaling by TRK-fused gene (TFG) protein

    International Nuclear Information System (INIS)

    Lee, Na-Rae; Shin, Han-Bo; Kim, Hye-In; Choi, Myung-Soo; Inn, Kyung-Soo

    2013-01-01

    Highlights: •TRK-fused gene product (TFG) interacts with TRIM25 upon viral infection. •TFG negatively regulates RIG-I mediated antiviral signaling. •TFG depletion leads to enhanced viral replication. •TFG act downstream of MAVS. -- Abstract: RIG-I (retinoic acid inducible gene I)-mediated antiviral signaling serves as the first line of defense against viral infection. Upon detection of viral RNA, RIG-I undergoes TRIM25 (tripartite motif protein 25)-mediated K63-linked ubiquitination, leading to type I interferon (IFN) production. In this study, we demonstrate that TRK-fused gene (TFG) protein, previously identified as a TRIM25-interacting protein, binds TRIM25 upon virus infection and negatively regulates RIG-I-mediated type-I IFN signaling. RIG-I-mediated IFN production and nuclear factor (NF)-κB signaling pathways were upregulated by the suppression of TFG expression. Furthermore, vesicular stomatitis virus (VSV) replication was significantly inhibited by small inhibitory hairpin RNA (shRNA)-mediated knockdown of TFG, supporting the suppressive role of TFG in RIG-I-mediated antiviral signaling. Interestingly, suppression of TFG expression increased not only RIG-I-mediated signaling but also MAVS (mitochondrial antiviral signaling protein)-induced signaling, suggesting that TFG plays a pivotal role in negative regulation of RNA-sensing, RIG-I-like receptor (RLR) family signaling pathways

  6. Tumor-Triggered Geometrical Shape Switch of Chimeric Peptide for Enhanced in Vivo Tumor Internalization and Photodynamic Therapy.

    Science.gov (United States)

    Han, Kai; Zhang, Jin; Zhang, Weiyun; Wang, Shibo; Xu, Luming; Zhang, Chi; Zhang, Xianzheng; Han, Heyou

    2017-03-28

    Geometrical shape of nanoparticles plays an important role in cellular internalization. However, the applicability in tumor selective therapeutics is still scarcely reported. In this article, we designed a tumor extracellular acidity-responsive chimeric peptide with geometrical shape switch for enhanced tumor internalization and photodynamic therapy. This chimeric peptide could self-assemble into spherical nanoparticles at physiological condition. While at tumor extracellular acidic microenvironment, chimeric peptide underwent detachment of acidity-sensitive 2,3-dimethylmaleic anhydride groups. The subsequent recovery of ionic complementarity between chimeric peptides resulted in formation of rod-like nanoparticles. Both in vitro and in vivo studies demonstrated that this acidity-triggered geometrical shape switch endowed chimeric peptide with accelerated internalization in tumor cells, prolonged accumulation in tumor tissue, enhanced photodynamic therapy, and minimal side effects. Our results suggested that fusing tumor microenvironment with geometrical shape switch should be a promising strategy for targeted drug delivery.

  7. β-Casein(94-123)-derived peptides differently modulate production of mucins in intestinal goblet cells.

    Science.gov (United States)

    Plaisancié, Pascale; Boutrou, Rachel; Estienne, Monique; Henry, Gwénaële; Jardin, Julien; Paquet, Armelle; Léonil, Joëlle

    2015-02-01

    We recently reported the identification of a peptide from yoghurts with promising potential for intestinal health: the sequence (94-123) of bovine β-casein. This peptide, composed of 30 amino acid residues, maintains intestinal homoeostasis through production of the secreted mucin MUC2 and of the transmembrane-associated mucin MUC4. Our study aimed to search for the minimal sequence responsible for the biological activity of β-CN(94-123) by using several strategies based on (i) known bioactive peptides encrypted in β-CN(94-123), (ii) in silico prediction of peptides reactivity and (iii) digestion of β-CN(94-123) by enzymes of intestinal brush border membranes. The revealed sequences were tested in vitro on human intestinal mucus-producing HT29-MTX cells. We demonstrated that β-CN(108-113) (an ACE-inhibitory peptide) and β-CN(114-119) (an opioid peptide named neocasomorphin-6) up-regulated MUC4 expression whereas levels of the secreted mucins MUC2 and MUC5AC remained unchanged. The digestion of β-CN(94-123) by intestinal enzymes showed that the peptides β-CN(94-108) and β-CN(117-123) were present throughout 1·5 to 3 h of digestion, respectively. These two peptides raised MUC5AC expression while β-CN(117-123) also induced a decrease in the level of MUC2 mRNA and protein. In addition, this inhibitory effect was reproduced in airway epithelial cells. In conclusion, β-CN(94-123) is a multifunctional molecule but only the sequence of 30 amino acids has a stimulating effect on the production of MUC2, a crucial factor of intestinal protection.

  8. First isolation of a novel thermostable antifungal peptide secreted by Aspergillus clavatus.

    Science.gov (United States)

    Skouri-Gargouri, Houda; Gargouri, Ali

    2008-11-01

    A novel antifungal peptide produced by an indigenous fungal strain (VR) of Aspergillus clavatus was purified. The antifungal peptide was enriched in the supernatant after heat treatment at 70 degrees C. The thermostable character was exploited in the first purification step, as purified peptide was obtained after ultrafiltration and reverse phase-HPLC on C18 column application. The purified peptide named "AcAFP" for A. clavatus antifungal peptide, has molecular mass of 5773Da determined by MALDI-ToF spectrometry. The N-terminal sequence showed a notable identity to the limited family of antifungal peptides produced by ascomycetes fungi. The AcAFP activity remains intact even after heat treatment at 100 degrees C for 1h confirming its thermostability. It exhibits a strong inhibitory activity against mycelial growth of several serious human and plant pathogenic fungi: Fusariuym oxysporum, Fusarium solani, Aspergillus niger, Botrytis cinerea, Alternaria solani, whereas AcAFP did not affect yeast and bacterial growth.

  9. Casein Hydrolysates by Lactobacillus brevis and Lactococcus lactis Proteases: Peptide Profile Discriminates Strain-Dependent Enzyme Specificity.

    Science.gov (United States)

    Bounouala, Fatima Zohra; Roudj, Salima; Karam, Nour-Eddine; Recio, Isidra; Miralles, Beatriz

    2017-10-25

    Casein from ovine and bovine milk were hydrolyzed with two extracellular protease preparations from Lactobacillus brevis and Lactococcus lactis. The hydrolysates were analyzed by HPLC-MS/MS for peptide identification. A strain-dependent peptide profile could be observed, regardless of the casein origin, and the specificity of these two proteases could be computationally ascribed. The cleavage pattern yielding phenylalanine, leucine, or tyrosine at C-terminal appeared both at L. lactis and Lb. brevis hydrolysates. However, the cleavage C-terminal to lysine was favored with Lb. brevis protease. The hydrolysates showed ACE-inhibitory activity with IC 50 in the 16-70 μg/mL range. Ovine casein hydrolysates yielded greater ACE-inhibitory activity. Previously described antihypertensive and opioid peptides were found in these ovine and bovine casein hydrolysates and prediction of the antihypertensive activity of the sequences based on quantitative structure and activity relationship (QSAR) was performed. This approach might represent a useful classification tool regarding health-related properties prior to further purification.

  10. Isolation and characterization of enterocin W, a novel two-peptide lantibiotic produced by Enterococcus faecalis NKR-4-1.

    Science.gov (United States)

    Sawa, Naruhiko; Wilaipun, Pongtep; Kinoshita, Seisuke; Zendo, Takeshi; Leelawatcharamas, Vichien; Nakayama, Jiro; Sonomoto, Kenji

    2012-02-01

    Enterococcus faecalis NKR-4-1 isolated from pla-ra produces a novel two-peptide lantibiotic, termed enterocin W, comprising Wα and Wβ. The structure of enterocin W exhibited similarity with that of plantaricin W. The two peptides acted synergistically, and their order of binding to the cell membrane was important for their inhibitory activity.

  11. Fused aromatic thienopyrazines: structure, properties and function

    KAUST Repository

    Mondal, Rajib; Ko, Sangwon; Bao, Zhenan

    2010-01-01

    Recent development of a fused aromatic thieno[3.4-b]pyrazine system and their application in optoelectronic devices are reviewed. Introduction of a fused aromatic unit followed by side chain engineering, dramatically enhanced the charge carrier

  12. pMPES: A Modular Peptide Expression System for the Delivery of Antimicrobial Peptides to the Site of Gastrointestinal Infections Using Probiotics

    Directory of Open Access Journals (Sweden)

    Kathryn Geldart

    2016-10-01

    Full Text Available Antimicrobial peptides are a promising alternative to traditional antibiotics, but their utility is limited by high production costs and poor bioavailability profiles. Bacterial production and delivery of antimicrobial peptides (AMPs directly at the site of infection may offer a path for effective therapeutic application. In this study, we have developed a vector that can be used for the production and secretion of seven antimicrobial peptides from both Escherichia coli MC1061 F’ and probiotic E.coli Nissle 1917. The vector pMPES (Modular Peptide Expression System employs the Microcin V (MccV secretion system and a powerful synthetic promoter to drive AMP production. Herein, we demonstrate the capacity of pMPES to produce inhibitory levels of MccV, Microcin L (MccL, Microcin N (McnN, Enterocin A (EntA, Enterocin P (EntP, Hiracin JM79 (HirJM79 and Enterocin B (EntB. To our knowledge, this is the first demonstration of such a broadly-applicable secretion system for AMP production. This type of modular expression system could expedite the development of sorely needed antimicrobial technologies

  13. Novel chimeric peptide with enhanced cell specificity and anti-inflammatory activity.

    Science.gov (United States)

    Kim, Young-Min; Kim, Nam-Hong; Lee, Jong-Wan; Jang, Jin-Sun; Park, Yung-Hoon; Park, Seong-Cheol; Jang, Mi-Kyeong

    2015-07-31

    An antimicrobial peptide (AMP), Hn-Mc, was designed by combining the N-terminus of HPA3NT3 and the C-terminus of melittin. This chimeric AMP exhibited potent antibacterial activity with low minimal inhibitory concentrations (MICs), ranging from 1 to 2 μM against four drug-susceptible bacteria and ten drug-resistant bacteria. Moreover, the hemolysis and cytotoxicity was reduced significantly compared to those of the parent peptides, highlighting its high cell selectivity. The morphological changes in the giant unilamellar vesicles and bacterial cell surfaces caused by the Hn-Mc peptide suggested that it killed the microbial cells by damaging the membrane envelope. An in vivo study also demonstrated the antibacterial activity of the Hn-Mc peptide in a mouse model infected with drug-resistant bacteria. In addition, the chimeric peptide inhibited the expression of lipopolysaccharide (LPS)-induced cytokines in RAW 264.7 cells by preventing the interaction between LPS and Toll-like receptors. These results suggest that this chimeric peptide is an antimicrobial and anti-inflammatory candidate as a pharmaceutic agent. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Heparin-binding peptide as a novel affinity tag for purification of recombinant proteins.

    Science.gov (United States)

    Morris, Jacqueline; Jayanthi, Srinivas; Langston, Rebekah; Daily, Anna; Kight, Alicia; McNabb, David S; Henry, Ralph; Kumar, Thallapuranam Krishnaswamy Suresh

    2016-10-01

    Purification of recombinant proteins constitutes a significant part of the downstream processing in biopharmaceutical industries. Major costs involved in the production of bio-therapeutics mainly depend on the number of purification steps used during the downstream process. Affinity chromatography is a widely used method for the purification of recombinant proteins expressed in different expression host platforms. Recombinant protein purification is achieved by fusing appropriate affinity tags to either N- or C- terminus of the target recombinant proteins. Currently available protein/peptide affinity tags have proved quite useful in the purification of recombinant proteins. However, these affinity tags suffer from specific limitations in their use under different conditions of purification. In this study, we have designed a novel 34-amino acid heparin-binding affinity tag (HB-tag) for the purification of recombinant proteins expressed in Escherichia coli (E. coli) cells. HB-tag fused recombinant proteins were overexpressed in E. coli in high yields. A one-step heparin-Sepharose-based affinity chromatography protocol was developed to purify HB-fused recombinant proteins to homogeneity using a simple sodium chloride step gradient elution. The HB-tag has also been shown to facilitate the purification of target recombinant proteins from their 8 M urea denatured state(s). The HB-tag has been demonstrated to be successfully released from the fusion protein by an appropriate protease treatment to obtain the recombinant target protein(s) in high yields. Results of the two-dimensional NMR spectroscopy experiments indicate that the purified recombinant target protein(s) exist in the native conformation. Polyclonal antibodies raised against the HB-peptide sequence, exhibited high binding specificity and sensitivity to the HB-fused recombinant proteins (∼10 ng) in different crude cell extracts obtained from diverse expression hosts. In our opinion, the HB-tag provides a

  15. Soluble N-Ethylmaleimide-Sensitive Factor Attachment Protein Receptor-Derived Peptides for Regulation of Mast Cell Degranulation.

    Science.gov (United States)

    Yang, Yoosoo; Kong, Byoungjae; Jung, Younghoon; Park, Joon-Bum; Oh, Jung-Mi; Hwang, Jaesung; Cho, Jae Youl; Kweon, Dae-Hyuk

    2018-01-01

    Vesicle-associated V-soluble N -ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins and target membrane-associated T-SNAREs (syntaxin 4 and SNAP-23) assemble into a core trans -SNARE complex that mediates membrane fusion during mast cell degranulation. This complex plays pivotal roles at various stages of exocytosis from the initial priming step to fusion pore opening and expansion, finally resulting in the release of the vesicle contents. In this study, peptides with the sequences of various SNARE motifs were investigated for their potential inhibitory effects against SNARE complex formation and mast cell degranulation. The peptides with the sequences of the N-terminal regions of vesicle-associated membrane protein 2 (VAMP2) and VAMP8 were found to reduce mast cell degranulation by inhibiting SNARE complex formation. The fusion of protein transduction domains to the N-terminal of each peptide enabled the internalization of the fusion peptides into the cells equally as efficiently as cell permeabilization by streptolysin-O without any loss of their inhibitory activities. Distinct subsets of mast cell granules could be selectively regulated by the N-terminal-mimicking peptides derived from VAMP2 and VAMP8, and they effectively decreased the symptoms of atopic dermatitis in mouse models. These results suggest that the cell membrane fusion machinery may represent a therapeutic target for atopic dermatitis.

  16. Three-dimensional printing of transparent fused silica glass

    Science.gov (United States)

    Kotz, Frederik; Arnold, Karl; Bauer, Werner; Schild, Dieter; Keller, Nico; Sachsenheimer, Kai; Nargang, Tobias M.; Richter, Christiane; Helmer, Dorothea; Rapp, Bastian E.

    2017-04-01

    Glass is one of the most important high-performance materials used for scientific research, in industry and in society, mainly owing to its unmatched optical transparency, outstanding mechanical, chemical and thermal resistance as well as its thermal and electrical insulating properties. However, glasses and especially high-purity glasses such as fused silica glass are notoriously difficult to shape, requiring high-temperature melting and casting processes for macroscopic objects or hazardous chemicals for microscopic features. These drawbacks have made glasses inaccessible to modern manufacturing technologies such as three-dimensional printing (3D printing). Using a casting nanocomposite, here we create transparent fused silica glass components using stereolithography 3D printers at resolutions of a few tens of micrometres. The process uses a photocurable silica nanocomposite that is 3D printed and converted to high-quality fused silica glass via heat treatment. The printed fused silica glass is non-porous, with the optical transparency of commercial fused silica glass, and has a smooth surface with a roughness of a few nanometres. By doping with metal salts, coloured glasses can be created. This work widens the choice of materials for 3D printing, enabling the creation of arbitrary macro- and microstructures in fused silica glass for many applications in both industry and academia.

  17. Antihypertensive activity of peptides identified in the in vitro gastrointestinal digest of pork meat.

    Science.gov (United States)

    Escudero, Elizabeth; Toldrá, Fidel; Sentandreu, Miguel Angel; Nishimura, Hitoshi; Arihara, Keizo

    2012-07-01

    This study investigated the in vivo antihypertensive activity of three novel peptides identified in the in vitro digest of pork meat. These peptides were RPR, KAPVA and PTPVP and all of them showed significant antihypertensive activity after oral administration to spontaneously hypertensive rats, RPR being the peptide with the greatest in vivo activity. To our knowledge, this is the first report showing the in vivo antihypertensive action of the three peptides from nebulin (RPR) and titin (KAPVA and PTPVP), thus confirming their reported in vitro angiotensin I-converting enzyme (ACE) inhibitory activity. These findings suggest that pork meat could constitute a source of bioactive constituents that could be utilized in functional foods or nutraceuticals. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Fuse Modeling for Reliability Study of Power Electronic Circuits

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Iannuzzo, Francesco; Blaabjerg, Frede

    2017-01-01

    This paper describes a comprehensive modeling approach on reliability of fuses used in power electronic circuits. When fuses are subjected to current pulses, cyclic temperature stress is introduced to the fuse element and will wear out the component. Furthermore, the fuse may be used in a large......, and rated voltage/current are opposed to shift in time to effect early breaking during the normal operation of the circuit. Therefore, in such cases, a reliable protection required for the other circuit components will not be achieved. The thermo-mechanical models, fatigue analysis and thermo...

  19. Antibacterial activity of novel cationic peptides against clinical isolates of multi-drug resistant Staphylococcus pseudintermedius from infected dogs.

    Directory of Open Access Journals (Sweden)

    Mohamed F Mohamed

    Full Text Available Staphylococcus pseudintermedius is a major cause of skin and soft tissue infections in companion animals and has zoonotic potential. Additionally, methicillin-resistant S. pseudintermedius (MRSP has emerged with resistance to virtually all classes of antimicrobials. Thus, novel treatment options with new modes of action are required. Here, we investigated the antimicrobial activity of six synthetic short peptides against clinical isolates of methicillin-susceptible and MRSP isolated from infected dogs. All six peptides demonstrated potent anti-staphylococcal activity regardless of existing resistance phenotype. The most effective peptides were RRIKA (with modified C terminus to increase amphipathicity and hydrophobicity and WR-12 (α-helical peptide consisting exclusively of arginine and tryptophan with minimum inhibitory concentration50 (MIC50 of 1 µM and MIC90 of 2 µM. RR (short anti-inflammatory peptide and IK8 "D isoform" demonstrated good antimicrobial activity with MIC50 of 4 µM and MIC90 of 8 µM. Penetratin and (KFF3K (two cell penetrating peptides were the least effective with MIC50 of 8 µM and MIC90 of 16 µM. Killing kinetics revealed a major advantage of peptides over conventional antibiotics, demonstrating potent bactericidal activity within minutes. Studies with propidium iodide and transmission electron microscopy revealed that peptides damaged the bacterial membrane leading to leakage of cytoplasmic contents and consequently, cell death. A potent synergistic increase in the antibacterial effect of the cell penetrating peptide (KFF3K was noticed when combined with other peptides and with antibiotics. In addition, all peptides displayed synergistic interactions when combined together. Furthermore, peptides demonstrated good therapeutic indices with minimal toxicity toward mammalian cells. Resistance to peptides did not evolve after 10 passages of S. pseudintermedius at sub-inhibitory concentration. However, the MICs of amikacin

  20. Sungsanpin, a lasso peptide from a deep-sea streptomycete.

    Science.gov (United States)

    Um, Soohyun; Kim, Young-Joo; Kwon, Hyuknam; Wen, He; Kim, Seong-Hwan; Kwon, Hak Cheol; Park, Sunghyouk; Shin, Jongheon; Oh, Dong-Chan

    2013-05-24

    Sungsanpin (1), a new 15-amino-acid peptide, was discovered from a Streptomyces species isolated from deep-sea sediment collected off Jeju Island, Korea. The planar structure of 1 was determined by 1D and 2D NMR spectroscopy, mass spectrometry, and UV spectroscopy. The absolute configurations of the stereocenters in this compound were assigned by derivatizations of the hydrolysate of 1 with Marfey's reagents and 2,3,4,6-tetra-O-acetyl-β-d-glucopyranosyl isothiocyanate, followed by LC-MS analysis. Careful analysis of the ROESY NMR spectrum and three-dimensional structure calculations revealed that sungsanpin possesses the features of a lasso peptide: eight amino acids (-Gly(1)-Phe-Gly-Ser-Lys-Pro-Ile-Asp(8)-) that form a cyclic peptide and seven amino acids (-Ser(9)-Phe-Gly-Leu-Ser-Trp-Leu(15)) that form a tail that loops through the ring. Sungsanpin is thus the first example of a lasso peptide isolated from a marine-derived microorganism. Sungsanpin displayed inhibitory activity in a cell invasion assay with the human lung cancer cell line A549.

  1. Pharmacological characterization of potent and selective NaV1.7 inhibitors engineered from Chilobrachys jingzhao tarantula venom peptide JzTx-V.

    Directory of Open Access Journals (Sweden)

    Bryan D Moyer

    Full Text Available Identification of voltage-gated sodium channel NaV1.7 inhibitors for chronic pain therapeutic development is an area of vigorous pursuit. In an effort to identify more potent leads compared to our previously reported GpTx-1 peptide series, electrophysiology screening of fractionated tarantula venom discovered the NaV1.7 inhibitory peptide JzTx-V from the Chinese earth tiger tarantula Chilobrachys jingzhao. The parent peptide displayed nominal selectivity over the skeletal muscle NaV1.4 channel. Attribute-based positional scan analoging identified a key Ile28Glu mutation that improved NaV1.4 selectivity over 100-fold, and further optimization yielded the potent and selective peptide leads AM-8145 and AM-0422. NMR analyses revealed that the Ile28Glu substitution changed peptide conformation, pointing to a structural rationale for the selectivity gains. AM-8145 and AM-0422 as well as GpTx-1 and HwTx-IV competed for ProTx-II binding in HEK293 cells expressing human NaV1.7, suggesting that these NaV1.7 inhibitory peptides interact with a similar binding site. AM-8145 potently blocked native tetrodotoxin-sensitive (TTX-S channels in mouse dorsal root ganglia (DRG neurons, exhibited 30- to 120-fold selectivity over other human TTX-S channels and exhibited over 1,000-fold selectivity over other human tetrodotoxin-resistant (TTX-R channels. Leveraging NaV1.7-NaV1.5 chimeras containing various voltage-sensor and pore regions, AM-8145 mapped to the second voltage-sensor domain of NaV1.7. AM-0422, but not the inactive peptide analog AM-8374, dose-dependently blocked capsaicin-induced DRG neuron action potential firing using a multi-electrode array readout and mechanically-induced C-fiber spiking in a saphenous skin-nerve preparation. Collectively, AM-8145 and AM-0422 represent potent, new engineered NaV1.7 inhibitory peptides derived from the JzTx-V scaffold with improved NaV selectivity and biological activity in blocking action potential firing in both

  2. A Chimeric Peptide Composed of a Dermaseptin Derivative and an RNA III-Inhibiting Peptide Prevents Graft-Associated Infections by Antibiotic-Resistant Staphylococci

    Science.gov (United States)

    Balaban, Naomi; Gov, Yael; Giacometti, Andrea; Cirioni, Oscar; Ghiselli, Roberto; Mocchegiani, Federico; Orlando, Fiorenza; D'Amato, Giuseppina; Saba, Vittorio; Scalise, Giorgio; Bernes, Sabina; Mor, Amram

    2004-01-01

    Staphylococcal bacteria are a prevalent cause of infections associated with foreign bodies and indwelling medical devices. Bacteria are capable of escaping antibiotic treatment through encapsulation into biofilms. RNA III-inhibiting peptide (RIP) is a heptapeptide that inhibits staphylococcal biofilm formation by obstructing quorum-sensing mechanisms. K4-S4(1-13)a is a 13-residue dermaseptin derivative (DD13) believed to kill bacteria via membrane disruption. We tested each of these peptides as well as a hybrid construct, DD13-RIP, for their ability to inhibit bacterial proliferation and suppress quorum sensing in vitro and for their efficacy in preventing staphylococcal infection in a rat graft infection model with methicillin-resistant Staphylococcus aureus (MRSA) or S. epidermidis (MRSE). In vitro, proliferation assays demonstrated that RIP had no inhibitory effect, while DD13-RIP and DD13 were equally effective, and that the chimeric peptide but not DD13 was slightly more effective than RIP in inhibiting RNA III synthesis, a regulatory RNA molecule important for staphylococcal pathogenesis. In vivo, the three peptides reduced graft-associated bacterial load in a dose-dependent manner, but the hybrid peptide was most potent in totally preventing staphylococcal infections at the lowest dose. In addition, each of the peptides acted synergistically with antibiotics. The data indicate that RIP and DD13 act in synergy by attacking bacteria simultaneously by two different mechanisms. Such a chimeric peptide may be useful for coating medical devices to prevent drug-resistant staphylococcal infections. PMID:15215107

  3. Influence of System Parameters on Fuse Protection Use in Regenerative DC Drives

    Directory of Open Access Journals (Sweden)

    Isa Salman Qamber

    2009-06-01

    Full Text Available Current limiting fuses are widely used to protect the thyristors in DC drive systems. One very important problem is the choice of the correct voltage rating for fuses protecting regenerative DC drives, where many types of fault may occur, which makes fuse protection difficult. In the event of a commutation failure while regenerating, the fuses need to interrupt the loop supplied by the AC and DC voltages acting in series, which is the most difficult case for protection by fuses. In this paper a detailed study of the complete interruption process has been investigated by modeling of arcing process of the fuse protection against the regenerative circuit internal commutation fault. The effect of varying the motor time constant, supply impedance, number of fuses used to clear the fault and DC machine rating on the total transient response is studied. The model of a 200 A fuse is employed in this study. Fuses in series with both the semiconductor devices (F1 and fuses in AC lines (F2 are considered. Comparison was made between arc energy produced for fuses protecting the regenerative circuit if failure occurs, with the arc energy produced in a standard AC test in order to investigate the required voltage rating for the fuse.

  4. Antimicrobial activity and safety evaluation of peptides isolated from the hemoglobin of chickens.

    Science.gov (United States)

    Hu, Fengjiao; Wu, Qiaoxing; Song, Shuang; She, Ruiping; Zhao, Yue; Yang, Yifei; Zhang, Meikun; Du, Fang; Soomro, Majid Hussain; Shi, Ruihan

    2016-12-05

    Hemoglobin is a rich source of biological peptides. As a byproduct and even wastewater of poultry-slaughtering facilities, chicken blood is one of the most abundant source of hemoglobin. In this study, the chicken hemoglobin antimicrobial peptides (CHAP) were isolated and the antimicrobial and bactericidal activities were tested by the agarose diffusion assay, minimum inhibitory concentration (MIC) analysis, minimal bactericidal concentration (MBC) analysis, and time-dependent inhibitory and bactericidal assays. The results demonstrated that CHAP had potent and rapid antimicrobial activity against 19 bacterial strains, including 9 multidrug-resistant bacterial strains. Bacterial biofilm and NaCl permeability assays, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were further performed to detect the mechanism of its antimicrobial effect. Additionally, CHAP showed low hemolytic activity, embryo toxicity, and high stability in different temperatures and animal plasma. CHAP may have great potential for expanding production and development value in animal medication, the breeding industry and environment protection.

  5. Directed evolution of an LBP/CD14 inhibitory peptide and its anti-endotoxin activity.

    Directory of Open Access Journals (Sweden)

    Li Fang

    Full Text Available BACKGROUND: LPS-binding protein (LBP and its ligand CD14 are located upstream of the signaling pathway for LPS-induced inflammation. Blocking LBP and CD14 binding might prevent LPS-induced inflammation. In previous studies, we obtained a peptide analog (MP12 for the LBP/CD14 binding site and showed that this peptide analog had anti-endotoxin activity. In this study, we used in vitro directed evolution for this peptide analog to improve its in vivo and in vitro anti-endotoxin activity. METHODS: We used error-prone PCR (ep-PCR and induced mutations in the C-terminus of LBP and attached the PCR products to T7 phages to establish a mutant phage display library. The positive clones that competed with LBP for CD14 binding was obtained by screening. We used both in vivo and in vitro experiments to compare the anti-endotoxin activities of a polypeptide designated P1 contained in a positive clone and MP12. RESULTS: 11 positive clones were obtained from among target phages. Sequencing showed that 9 positive clones had a threonine (T to methionine (M mutation in amino acid 287 of LBP. Compared to polypeptide MP12, polypeptide P1 significantly inhibited LPS-induced TNF-α expression and NF-κB activity in U937 cells (P<0.05. Compared to MP12, P1 significantly improved arterial oxygen pressure, an oxygenation index, and lung pathology scores in LPS-induced ARDS rats (P<0.05. CONCLUSION: By in vitro directed evolution of peptide analogs for the LBP/CD14 binding site, we established a new polypeptide (P1 with a threonine (T-to-methionine (M mutation in amino acid 287 of LBP. This polypeptide had high anti-endotoxin activity in vitro and in vivo, which suggested that amino acid 287 in the C-terminus of LBP may play an important role in LBP binding with CD14.

  6. Buwchitin: a ruminal peptide with antimicrobial potential against Enterococcus faecalis

    Science.gov (United States)

    Oyama, Linda B.; Crochet, Jean-Adrien; Edwards, Joan E.; Girdwood, Susan E.; Cookson, Alan R.; Fernandez-Fuentes, Narcis; Hilpert, Kai; Golyshin, Peter N.; Golyshina, Olga V.; Privé, Florence; Hess, Matthias; Mantovani, Hilario C.; Creevey, Christopher J.; Huws, Sharon A.

    2017-07-01

    Antimicrobial peptides (AMPs) are gaining popularity as alternatives for treatment of bacterial infections and recent advances in omics technologies provide new platforms for AMP discovery. We sought to determine the antibacterial activity of a novel antimicrobial peptide, buwchitin, against Enterococcus faecalis. Buwchitin was identified from a rumen bacterial metagenome library, cloned, expressed and purified. The antimicrobial activity of the recombinant peptide was assessed using a broth microdilution susceptibility assay to determine the peptide's killing kinetics against selected bacterial strains. The killing mechanism of buwchitin was investigated further by monitoring its ability to cause membrane depolarization (diSC3(5) method) and morphological changes in E. faecalis cells. Transmission electron micrographs of buwchitin treated E. faecalis cells showed intact outer membranes with blebbing, but no major damaging effects and cell morphology changes. Buwchitin had negligible cytotoxicity against defibrinated sheep erythrocytes. Although no significant membrane leakage and depolarization was observed, buwchitin at minimum inhibitory concentration (MIC) was bacteriostatic against E. faecalis cells and inhibited growth in vitro by 70% when compared to untreated cells. These findings suggest that buwchitin, a rumen derived peptide, has potential for antimicrobial activity against E. faecalis.

  7. Buwchitin: A Ruminal Peptide with Antimicrobial Potential against Enterococcus faecalis

    Directory of Open Access Journals (Sweden)

    Linda B. Oyama

    2017-07-01

    Full Text Available Antimicrobial peptides (AMPs are gaining popularity as alternatives for treatment of bacterial infections and recent advances in omics technologies provide new platforms for AMP discovery. We sought to determine the antibacterial activity of a novel antimicrobial peptide, buwchitin, against Enterococcus faecalis. Buwchitin was identified from a rumen bacterial metagenome library, cloned, expressed and purified. The antimicrobial activity of the recombinant peptide was assessed using a broth microdilution susceptibility assay to determine the peptide's killing kinetics against selected bacterial strains. The killing mechanism of buwchitin was investigated further by monitoring its ability to cause membrane depolarization (diSC3(5 method and morphological changes in E. faecalis cells. Transmission electron micrographs of buwchitin treated E. faecalis cells showed intact outer membranes with blebbing, but no major damaging effects and cell morphology changes. Buwchitin had negligible cytotoxicity against defibrinated sheep erythrocytes. Although no significant membrane leakage and depolarization was observed, buwchitin at minimum inhibitory concentration (MIC was bacteriostatic against E. faecalis cells and inhibited growth in vitro by 70% when compared to untreated cells. These findings suggest that buwchitin, a rumen derived peptide, has potential for antimicrobial activity against E. faecalis.

  8. Fused aromatic thienopyrazines: structure, properties and function

    KAUST Repository

    Mondal, Rajib

    2010-01-01

    Recent development of a fused aromatic thieno[3.4-b]pyrazine system and their application in optoelectronic devices are reviewed. Introduction of a fused aromatic unit followed by side chain engineering, dramatically enhanced the charge carrier mobility in thin film transistor devices and mobilities up to 0.2 cm2/Vs were achieved. The optoelectronic properties of these fused aromatic thienopyrazine polymers (Eg = 1.3 to 1.6 eV, HOMO = -4.9 to -5.2 V) were tuned by introduction of various fused aromatic rings within thienopyrazine. By balancing the fundamental properties of these polymers, both high charge carrier mobilities and moderate PCEs in solar cells were achieved. Further, effects of copolymerizing units are discussed. Low band gap semiconducting polymer (Eg ∼ 1 eV) with high field effect mobility (0.044 cm2/Vs) was obtained using cyclopentadithiophene as copolymerizing unit. Finally, a molecular design approach to enhance the absorption coefficients is discussed, which resulted in improved power conversion efficiency in bulk heterojunction solar cells. © 2010 The Royal Society of Chemistry.

  9. Functional Use Database (FUse)

    Data.gov (United States)

    U.S. Environmental Protection Agency — There are five different files for this dataset: 1. A dataset listing the reported functional uses of chemicals (FUse) 2. All 729 ToxPrint descriptors obtained from...

  10. Process for manufacturing hollow fused-silica insulator cylinder

    Science.gov (United States)

    Sampayan, Stephen E.; Krogh, Michael L.; Davis, Steven C.; Decker, Derek E.; Rosenblum, Ben Z.; Sanders, David M.; Elizondo-Decanini, Juan M.

    2001-01-01

    A method for building hollow insulator cylinders that can have each end closed off with a high voltage electrode to contain a vacuum. A series of fused-silica round flat plates are fabricated with a large central hole and equal inside and outside diameters. The thickness of each is related to the electron orbit diameter of electrons that escape the material surface, loop, and return back. Electrons in such electron orbits can support avalanche mechanisms that result in surface flashover. For example, the thickness of each of the fused-silica round flat plates is about 0.5 millimeter. In general, the thinner the better. Metal, such as gold, is deposited onto each top and bottom surface of the fused-silica round flat plates using chemical vapor deposition (CVD). Eutectic metals can also be used with one alloy constituent on the top and the other on the bottom. The CVD, or a separate diffusion step, can be used to defuse the deposited metal deep into each fused-silica round flat plate. The conductive layer may also be applied by ion implantation or gas diffusion into the surface. The resulting structure may then be fused together into an insulator stack. The coated plates are aligned and then stacked, head-to-toe. Such stack is heated and pressed together enough to cause the metal interfaces to fuse, e.g., by welding, brazing or eutectic bonding. Such fusing is preferably complete enough to maintain a vacuum within the inner core of the assembled structure. A hollow cylinder structure results that can be used as a core liner in a dielectric wall accelerator and as a vacuum envelope for a vacuum tube device where the voltage gradients exceed 150 kV/cm.

  11. 29 CFR 1926.907 - Use of safety fuse.

    Science.gov (United States)

    2010-07-01

    ... way shall be forbidden. (b) The hanging of a fuse on nails or other projections which will cause a...-called “drop fuse” method of dropping or pushing a primer or any explosive with a lighted fuse attached...

  12. Dedication for Safety-Related Fuses used in Class-1E Power System

    International Nuclear Information System (INIS)

    Hong, Younghee

    2014-01-01

    The safety-related fuses used in class-1E power system provide overcurrent protection for electrical system and isolate the class 1E circuit from a fault or overload condition. These days, the number of nuclear grade suppliers has been reduced. Accordingly, commercial grade, instead of safety-related, fuses are procured and used in the utilities through the dedication process. Therefore, this paper introduces the commercial grade fuse dedication process/engineering and how to assure the quality requirements with this process and engineering. The fuses used in class-1E power system are to protect overcurrent and to isolate fault. Therefore the fuse for acceptance in order to improve the quality and reliability for commercial grade fuses shall be dedicated. The fuse resistance value may be useful as an indicator of acceptance. The current carrying capacity test can change the fuse performance properties. Therefore these critical characteristics are needed for additional review and analysis with fuse manufactures

  13. Fused-core particle technology in high-performance liquid chromatography: An overview

    Directory of Open Access Journals (Sweden)

    Joseph J. Kirkland

    2013-10-01

    Full Text Available The advent of superficially porous particles (SPPs for packed HPLC columns has changed the way that many practitioners have approached the problem of developing needed separations. The very high efficiency of such columns, combined with convenient operating conditions, modest back pressures and the ability to use conventional HPLC instruments has resulted in intense basic studies of SPP technology, and widespread applications in many sciences. This report contains an overview of the SPP technology first developed in 2006 by Advanced Materials Technology, Inc., for sub-3-μm particles, then expanded into a family of SPP products with different particle sizes, pore sizes and other physical parameters. This approach was designed so that each particle of the family could be optimized for separating a particular group of compounds, usually based on solute size. Keywords: Superficially porous particles, Fused-core particles, Core–shell particles, Peptides, Proteins, Drug separations

  14. Milk derived bioactive peptides and their impact on human health – A review

    Directory of Open Access Journals (Sweden)

    D.P. Mohanty

    2016-09-01

    Full Text Available Milk-derived bioactive peptides have been identified as potential ingredients of health-promoting functional foods. These bioactive peptides are targeted at diet-related chronic diseases especially the non-communicable diseases viz., obesity, cardiovascular diseases and diabetes. Peptides derived from the milk of cow, goat, sheep, buffalo and camel exert multifunctional properties, including anti-microbial, immune modulatory, anti-oxidant, inhibitory effect on enzymes, anti-thrombotic, and antagonistic activities against various toxic agents. Majority of those regulate immunological, gastrointestinal, hormonal and neurological responses, thereby playing a vital role in the prevention of cancer, osteoporosis, hypertension and other disorders as discussed in this review. For the commercial production of such novel bioactive peptides large scale technologies based on membrane separation and ion exchange chromatography methods have been developed. Separation and identification of those peptides and their pharmacodynamic parameters are necessary to transfer their potent functional properties into food applications. The present review summarizes the preliminary classes of bioactive milk-derived peptides along with their physiological functions, general characteristics and potential applications in health-care.

  15. Production of the blood pressure lowing peptides from brown alga ( Undaria pinnatifida)

    Science.gov (United States)

    Minoru, Sato; Takashi, Oba; Takao, Hosokawa; Toshiyasu, Yamaguchi; Toshiki, Nakano; Tadao, Saito; Koji, Muramoto; Takashi, Kahara; Katsura, Funayama; Akio, Kobayashi; Takahisa, Nakano

    2005-07-01

    Brown alga ( Undaria pinnatifida) was treated with alginate lyase and hydrolyzed using 17 kinds of proteases and the inhibitory activity of the hydrolysates for the angiotensin-I-converting enzyme (ACE) was measured. Four hydrolysates with potent ACE-inhibitory activity were administered singly and orally to spontaneously hypertensive rats (SHRs). The systolic blood pressure of SHRs decreases significantly after single oral administration of the brown alga hydrolysates by protease S ‘Amano’ (from Bacillus stearothermophilus) at the concentration of 10 (mg protein) (kg body weight)-1. In the 17 weeks of feeding experiment, 7-week-old SHRs were fed standard diet supplemented with the brown alga hydrolysates for 10 weeks. In SHRs fed 1.0 and 0.1% brown alga hydrolysates, elevating of systolic bloodpressure was significantly suppressed for 7 weeks. To elucidate the active components, the brown alga hydrolysates were fractionated by 1-butanol extraction and HPLC on a reverse-phase column. Seven kinds of ACE-inhibitory peptides were isolated and identified by amino acid composition analysis, sequence analysis, and LC-MS with the results Val-Tyr, Ile-Tyr, Ala-Trp, Phe-Tyr, Val-Trp, Ile-Trp, and Leu-Trp. Each peptide was determined to have an antihypertensive effect after a single oral administration in SHRs. The brown alga hydrolysates were also confirmed to decrease the blood pressure in humans.

  16. Gastric inhibitory peptide, serotonin, and glucagon are unexpected chloride secretagogues in the rectal gland of the skate (Leucoraja erinacea).

    Science.gov (United States)

    Kelley, Catherine A; Decker, Sarah E; Silva, Patricio; Forrest, John N

    2014-05-01

    Since the discovery of the rectal gland of the dogfish shark 50 years ago, experiments with this tissue have greatly aided our understanding of secondary active chloride secretion and the secretagogues responsible for this function. In contrast, very little is known about the rectal gland of skates. In the present experiments, we performed the first studies in the perfused rectal gland of the little skate (Leucoraja erinacea), an organ weighing less than one-tenth of the shark rectal gland. Our results indicate that the skate gland can be studied by modified perfusion techniques and in primary culture monolayers, and that secretion is blocked by the inhibitors of membrane proteins required for secondary active chloride secretion. Our major finding is that three G protein-coupled receptor agonists, the incretin gastric inhibitory polypeptide (GIP), also known as glucose-dependent insulinotropic peptide, as well as glucagon and serotonin, are unexpected potent chloride secretagogues in the skate but not the shark. Glucagon stimulated chloride secretion to a mean value of 1,661 ± 587 μeq·h(-1)·g(-1) and serotonin stimulated to 2,893 ± 699 μeq·h(-1)·g(-1). GIP stimulated chloride secretion to 3,733 ± 679 μeq·h(-1)·g(-1) and significantly increased tissue cAMP content compared with basal conditions. This is the first report of GIP functioning as a chloride secretagogue in any species or tissue.

  17. Peptides derived from tryptic hydrolysate of Bacillus subtilis culture suppress fungal spoilage of table grapes.

    Science.gov (United States)

    Zhang, Bo; Wang, Jingnan; Ning, Shuqing; Yuan, Quan; Chen, Xiangning; Zhang, Yanyan; Fan, Junfeng

    2018-01-15

    This study confirmed the anti-fungal effect of trypsin-treated Bacillus subtilis culture (BC) (tryptic hydrolysate, TH) on mold growth on Kyoho grapes. We examined the anti-fungal activity of TH by identifying TH peptides and performing a computational docking analysis. TH was more potent than untreated BC in suppressing fungal growth on grapes. Specifically, TH maintained grape freshness by inhibiting respiration and rachis browning, maintaining firmness, and preventing weight loss. Thirty-six inhibitory peptides against β-1,3-glucan synthase (GS) were screened from 126 TH peptides identified through proteomic analysis. Among them, 13 peptides bound tightly to GS active pockets with lower binding energies than that of GppNHp. The most potent peptides, LFEIDEELNEK and FATSDLNDLYR, were synthesized, and further experiments showed that these peptides had a highly suppressive effect on GS activity and Aspergillus niger and Penicillium chrysogenum growth. Our results confirm that tryptic treatment is effective for improving the anti-fungal activity of BC. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Tuning Liposome Membrane Permeability by Competitive Peptide Dimerization and Partitioning-Folding Interactions Regulated by Proteolytic Activity

    Science.gov (United States)

    Lim, Seng Koon; Sandén, Camilla; Selegård, Robert; Liedberg, Bo; Aili, Daniel

    2016-02-01

    Membrane active peptides are of large interest for development of drug delivery vehicles and therapeutics for treatment of multiple drug resistant infections. Lack of specificity can be detrimental and finding routes to tune specificity and activity of membrane active peptides is vital for improving their therapeutic efficacy and minimize harmful side effects. We describe a de novo designed membrane active peptide that partition into lipid membranes only when specifically and covalently anchored to the membrane, resulting in pore-formation. Dimerization with a complementary peptide efficiently inhibits formation of pores. The effect can be regulated by proteolytic digestion of the inhibitory peptide by the matrix metalloproteinase MMP-7, an enzyme upregulated in many malignant tumors. This system thus provides a precise and specific route for tuning the permeability of lipid membranes and a novel strategy for development of recognition based membrane active peptides and indirect enzymatically controlled release of liposomal cargo.

  19. Peptidyl prolyl isomerase Pin1-inhibitory activity of D-glutamic and D-aspartic acid derivatives bearing a cyclic aliphatic amine moiety.

    Science.gov (United States)

    Nakagawa, Hidehiko; Seike, Suguru; Sugimoto, Masatoshi; Ieda, Naoya; Kawaguchi, Mitsuyasu; Suzuki, Takayoshi; Miyata, Naoki

    2015-12-01

    Pin1 is a peptidyl prolyl isomerase that specifically catalyzes cis-trans isomerization of phosphorylated Thr/Ser-Pro peptide bonds in substrate proteins and peptides. Pin1 is involved in many important cellular processes, including cancer progression, so it is a potential target of cancer therapy. We designed and synthesized a novel series of Pin1 inhibitors based on a glutamic acid or aspartic acid scaffold bearing an aromatic moiety to provide a hydrophobic surface and a cyclic aliphatic amine moiety with affinity for the proline-binding site of Pin1. Glutamic acid derivatives bearing cycloalkylamino and phenylthiazole groups showed potent Pin1-inhibitory activity comparable with that of known inhibitor VER-1. The results indicate that steric interaction of the cyclic alkyl amine moiety with binding site residues plays a key role in enhancing Pin1-inhibitory activity. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. Coiled-coil forming peptides for the induction of silver nanoparticles

    International Nuclear Information System (INIS)

    Božič Abram, Sabina; Aupič, Jana; Dražić, Goran; Gradišar, Helena; Jerala, Roman

    2016-01-01

    Biopolymers with defined sequence patterns offer an attractive alternative for the formation of silver nanoparticle (AgNP). A set of coiled-coil dimer forming peptides was tested for their AgNP formation ability. Seventeen of those peptides mediated the formation of AgNPs in aqueous solution at neutral pH, while the formation of a coiled-coil dimer inhibited the nanoparticle generation. A QSAR regression model on the relationship between sequence and function suggests that in this peptide type the patterns KXQQ and KXEE are favorable, whereas Ala residues appear to have an inhibitory effect. UV–VIS spectra of the obtained nanoparticles gave a peak at around 420 nm, typical for AgNPs in the size range around 40 nm, which was confirmed by dynamic light scattering and transmission electron microscopy. Peptide-induced AgNPs exhibited good antibacterial activity, even after a 15 min contact time, while they had low toxicity to human cells at the same concentrations. These results show that our designed peptides generate AgNPs with antibacterial activity at mild conditions and might be used for antibacterial coatings. - Highlights: • 17 of the 30 tested coiled-coil forming peptides induce AgNP formation. • Coiled-coil dimer formation suppresses AgNP generation of individual peptides. • Size of the peptide-induced silver nanoparticles is around 40 nm. • QSAR analysis points to the importance of KXQQ and KXEE motifs for AgNP generation. • Peptide-induced silver nanoparticles exhibit antibacterial activity.

  1. Coiled-coil forming peptides for the induction of silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Božič Abram, Sabina [Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); Graduate School of Biomedicine, University of Ljubljana, Ljubljana 1000 (Slovenia); Aupič, Jana [Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); Doctoral Programme in Chemical Sciences, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana 1000 (Slovenia); Dražić, Goran [Laboratory for Materials Chemistry, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); Gradišar, Helena [Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); EN-FIST, Centre of Excellence, Trg Osvobodilne fronte 13, Ljubljana 1000 (Slovenia); Jerala, Roman, E-mail: roman.jerala@ki.si [Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana (Slovenia); EN-FIST, Centre of Excellence, Trg Osvobodilne fronte 13, Ljubljana 1000 (Slovenia)

    2016-04-08

    Biopolymers with defined sequence patterns offer an attractive alternative for the formation of silver nanoparticle (AgNP). A set of coiled-coil dimer forming peptides was tested for their AgNP formation ability. Seventeen of those peptides mediated the formation of AgNPs in aqueous solution at neutral pH, while the formation of a coiled-coil dimer inhibited the nanoparticle generation. A QSAR regression model on the relationship between sequence and function suggests that in this peptide type the patterns KXQQ and KXEE are favorable, whereas Ala residues appear to have an inhibitory effect. UV–VIS spectra of the obtained nanoparticles gave a peak at around 420 nm, typical for AgNPs in the size range around 40 nm, which was confirmed by dynamic light scattering and transmission electron microscopy. Peptide-induced AgNPs exhibited good antibacterial activity, even after a 15 min contact time, while they had low toxicity to human cells at the same concentrations. These results show that our designed peptides generate AgNPs with antibacterial activity at mild conditions and might be used for antibacterial coatings. - Highlights: • 17 of the 30 tested coiled-coil forming peptides induce AgNP formation. • Coiled-coil dimer formation suppresses AgNP generation of individual peptides. • Size of the peptide-induced silver nanoparticles is around 40 nm. • QSAR analysis points to the importance of KXQQ and KXEE motifs for AgNP generation. • Peptide-induced silver nanoparticles exhibit antibacterial activity.

  2. Bioactive peptides released from in vitro digestion of human milk with or without pasteurization.

    Science.gov (United States)

    Wada, Yasuaki; Lönnerdal, Bo

    2015-04-01

    Pasteurized donor human milk (HM) serves as the best alternative for breast-feeding when availability of mother's milk is limited. Pasteurization is also applied to mother's own milk for very low birth weight infants, who are vulnerable to microbial infection. Whether pasteurization affects protein digestibility and therefore modulates the profile of bioactive peptides released from HM proteins by gastrointestinal digestion, has not been examined to date. HM with and without pasteurization (62.5 °C for 30 min) were subjected to in vitro gastrointestinal digestion, followed by peptidomic analysis to compare the formation of bioactive peptides. Some of the bioactive peptides, such as caseinophosphopeptide homologues, a possible opioid peptide (or propeptide), and an antibacterial peptide, were present in undigested HM and showed resistance to in vitro digestion, suggesting that these peptides are likely to exert their bioactivities in the gastrointestinal lumen, or be stably transported to target organs. In vitro digestion of HM released a large variety of bioactive peptides such as angiotensin I-converting enzyme-inhibitory, antioxidative, and immunomodulatory peptides. Bioactive peptides were released largely in the same manner with and without pasteurization. Provision of pasteurized HM may be as beneficial as breast-feeding in terms of milk protein-derived bioactive peptides.

  3. Vasorelaxing and antihypertensive activities of synthesized peptides derived from computer-aided simulation of pepsin hydrolysis of yam dioscorin

    OpenAIRE

    Lin, Yin-Shiou; Lu, Yeh-Lin; Wang, Guei-Jane; Liang, Hong-Jen; Hou, Wen-Chi

    2014-01-01

    Background We reported that yam dioscorin and its peptic hydrolysates exhibited ACE inhibition and antihypertensive effects on SHRs, however, the active peptides are not really isolated until now. Using ACE inhibitory screenings, two penta-peptides, KTCGY and KRIHF, were selected for ex vivo and in vivo experiments. Results KTCGY, KRIHF, and captopril were shown to have similar vasodilating effects against phenylephrine (PE)-induced tensions in rat endothelium-dependent thoracic aortic rings,...

  4. Biomimetic and Aggregation-Driven Crystallization Route for Room-Temperature Material Synthesis: Growth of β-Ga2O3 Nanoparticles Using Peptide Assemblies as Nanoreactors

    Science.gov (United States)

    Lee, Sang-Yup; Gao, Xueyun; Matsui, Hiroshi

    2008-01-01

    The room temperature synthesis of β-Ga2O3 nanocrystal was examined by coupling two biomimetic crystallization techniques, the enzymatic peptide nano-assembly templating and the aggregation-driven crystallization. The catalytic template of peptide assembly nucleated and mineralized primary β-Ga2O3 crystals, and then fused them to grow single-crystalline and monodisperse nanoparticles in the cavity of the peptide assembly at room temperature. In this work, the peptide assembly was exploited as a nano-reactor with an enzymatic functionality catalyzing the hydrolysis of gallium precursors. In addition, the characteristic ring-structure of peptide assembly is expected to provide an efficient dehydration pathway and the crystallization control over the surface tension, which are advantageous for the β-Ga2O3 crystal growth. This multifunctional peptide assembly could be applied for syntheses of a variety of nanomaterials that are kinetically difficult to grow at room temperature. PMID:17302413

  5. A study to evaluate the potential of an in silico approach for predicting dipeptidyl peptidase-IV inhibitory activity in vitro of protein hydrolysates.

    Science.gov (United States)

    Wang, Tzu-Yuan; Hsieh, Cheng-Hong; Hung, Chuan-Chuan; Jao, Chia-Ling; Lin, Pei-Yi; Hsieh, You-Liang; Hsu, Kuo-Chiang

    2017-11-01

    A total of 294 edible protein sequences and 5 commercial proteases listed in the BIOPEP database were analyzed in silico. The frequency (A), a parameter in silico described previously, was examined further to calculating the ratio of truncated peptides with Xaa-proline and/or Xaa-alanine to all peptide fragments in a protein hydrolyzed with a protease, using the BIOPEP database. Then the in vitro DPP-IV inhibitory activity was determined using the same 15 protein and protease combinations to evaluate their relationship. The result shows that A values considering the number of Xaa-proline+Xaa-alanine exhibited a strong correlation with in vitro DPP-IV inhibition rates by Pearson's correlation analysis (r=0.6993; Psilico approach is effective to predict DPP-IV inhibitory activities in vitro of protein hydrolysates. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Peptide inhibition of human cytomegalovirus infection

    Directory of Open Access Journals (Sweden)

    Morris Cindy A

    2011-02-01

    Full Text Available Abstract Background Human cytomegalovirus (HCMV is the most prevalent congenital viral infection in the United States and Europe causing significant morbidity and mortality to both mother and child. HCMV is also an opportunistic pathogen in immunocompromised individuals, including human immunodeficiency virus (HIV- infected patients with AIDS, and solid organ and allogeneic stem cell transplantation recipients. Current treatments for HCMV-associated diseases are insufficient due to the emergence of drug-induced resistance and cytotoxicity, necessitating novel approaches to limit HCMV infection. The aim of this study was to develop therapeutic peptides targeting glycoprotein B (gB, a major glycoprotein of HCMV that is highly conserved across the Herpesviridae family, that specifically inhibit fusion of the viral envelope with the host cell membrane preventing HCMV entry and infection. Results Using the Wimley-White Interfacial Hydrophobicity Scale (WWIHS, several regions within gB were identified that display a high potential to interact with lipid bilayers of cell membranes and hydrophobic surfaces within proteins. The ability of synthetic peptides analogous to WWIHS-positive sequences of HCMV gB to inhibit viral infectivity was evaluated. Human foreskin fibroblasts (HFF were infected with the Towne-GFP strain of HCMV (0.5 MOI, preincubated with peptides at a range of concentrations (78 nm to 100 μM, and GFP-positive cells were visualized 48 hours post-infection by fluorescence microscopy and analyzed quantitatively by flow cytometry. Peptides that inhibited HCMV infection demonstrated different inhibitory concentration curves indicating that each peptide possesses distinct biophysical properties. Peptide 174-200 showed 80% inhibition of viral infection at a concentration of 100 μM, and 51% and 62% inhibition at concentrations of 5 μM and 2.5 μM, respectively. Peptide 233-263 inhibited infection by 97% and 92% at concentrations of 100

  7. Characterization of antidiabetic and antihypertensive properties of canary seed (Phalaris canariensis L.) peptides.

    Science.gov (United States)

    Estrada-Salas, Patricia A; Montero-Morán, Gabriela M; Martínez-Cuevas, Pedro P; González, Carmen; Barba de la Rosa, Ana P

    2014-01-15

    Canary grass is used as traditional food for diabetes and hypertension treatment. The aim of this work is to characterize the biological activity of encrypted peptides released after gastrointestinal digestion of canary seed proteins. Canary peptides showed 43.5% inhibition of dipeptidyl peptidase IV (DPPIV) and 73.5% inhibition of angiotensin-converting enzyme (ACE) activity. An isolated perfused rat heart system was used to evaluate the canary seed vasoactive effect. Nitric oxide (NO), a major vasodilator agent, was evaluated in the venous effluent from isolated perfused rat heart. Canary seed peptides (1 μg/mL) were able to induce the production of NO (12.24 μM) in amounts similar to those induced by captopril (CPT) and bradykinin (BK). These results show that encrypted peptides in canary seed have inhibitory activity against DPPIV and ACE, enzymes that are targets for diabetes and hypertension treatments.

  8. Medium Effects on Minimum Inhibitory Concentrations of Nylon-3 Polymers against E. coli

    Science.gov (United States)

    Choi, Heejun; Chakraborty, Saswata; Liu, Runhui; Gellman, Samuel H.; Weisshaar, James C.

    2014-01-01

    Minimum inhibitory concentrations (MICs) against E. coli were measured for three nylon-3 polymers using Luria-Bertani broth (LB), brain-heart infusion broth (BHI), and a chemically defined complete medium (EZRDM). The polymers differ in the ratio of hydrophobic to cationic subunits. The cationic homopolymer is inert against E. coli in BHI and LB, but becomes highly potent in EZRDM. A mixed hydrophobic/cationic polymer with a hydrophobic t-butylbenzoyl group at its N-terminus is effective in BHI, but becomes more effective in EZRDM. Supplementation of EZRDM with the tryptic digest of casein (often found in LB) recapitulates the LB and BHI behavior. Additional evidence suggests that polyanionic peptides present in LB and BHI may form electrostatic complexes with cationic polymers, decreasing activity by diminishing binding to the anionic lipopolysaccharide layer of E. coli. In contrast, two natural antimicrobial peptides show no medium effects. Thus, the use of a chemically defined medium helps to reveal factors that influence antimicrobial potency of cationic polymers and functional differences between these polymers and evolved antimicrobial peptides. PMID:25153714

  9. Anti-dengue virus serotype 2 activity and mode of action of a novel peptide.

    Science.gov (United States)

    Chew, M-F; Tham, H-W; Rajik, M; Sharifah, S H

    2015-10-01

    To identify a novel antiviral peptide against dengue virus serotype 2 (DENV-2) by screening a phage display peptide library and to evaluate its in vitro antiviral activity and mode of action. A phage display peptide library was biopanned against purified DENV-2 and resulted in the identification and selection of a peptide (peptide gg-ww) for further investigation. ELISA was performed, and peptide gg-ww was shown to possess the highest binding affinity against DENV-2. Thus, peptide gg-ww was synthesized for cytotoxicity and antiviral assays. Virus plaque reduction assay, real-time PCR and immunofluorescence assay were used to investigate the inhibitory effect of peptide gg-ww on DENV-2 infection in Vero cells. Three different assays (pre-, simultaneous and post-treatments assays) were performed to investigate the peptide's mode of action. Results indicated that peptide gg-ww possessed strong antiviral activity with a ~96% inhibition rate, which was achieved at 250 μmol l(-1) . Viral replication was inhibited during a simultaneous treatment assay, indicating that the entry of the virus was impeded by this peptide. Peptide gg-ww displayed antiviral action against DENV-2 by targeting an early stage of viral replication (i.e. during viral entry). Peptide gg-ww may represent a new therapeutic candidate for the treatment of DENV infections and is a potential candidate to be developed as a peptide drug. © 2015 The Society for Applied Microbiology.

  10. Fused upper central incisors: management of two clinical cases

    OpenAIRE

    Sfasciotti, Gian Luca; Marini, Roberta; Bossù, Maurizio; Ierardo, Gaetano; Annibali, Susanna

    2012-01-01

    This paper reports the management of two clinical cases, in which the upper right central incisor was fused with a supernumerary tooth and the upper left central incisor was macrodontic. A radiographic examination revealed that the fused teeth had two separate roots. Hemisectioning of the fused teeth was performed, the supernumerary portion was extracted and the remaining part was reshaped to remove any sharp margins and to achieve a normal morphology. The macrodontic central incisors were no...

  11. Fused Heterocyclic Compounds as Potent Indoleamine-2,3-dioxygenase 1 Inhibitors.

    Science.gov (United States)

    Panda, Subhankar; Roy, Ashalata; Deka, Suman Jyoti; Trivedi, Vishal; Manna, Debasis

    2016-12-08

    Uncontrolled metabolism of l-tryptophan (l-Trp) in the immune system has been recognized as a critical cellular process in immune tolerance. Indoleamine 2,3-dioxygenase 1 (IDO1) enzyme plays an important role in the metabolism of a local l-Trp through the kynurenine pathway in the immune systems. In this regard, IDO1 has emerged as a therapeutic target for the treatment of diseases that are associated with immune suppression like chronic infections, cancer, and others. In this study, we synthesized a series of pyridopyrimidine, pyrazolopyranopyrimidine, and dipyrazolopyran derivatives. Further lead optimizations directed to the identification of potent compounds, 4j and 4l (IC 50 = 260 and 151 nM, respectively). These compounds also exhibited IDO1 inhibitory activities in the low nanomolar range in MDA-MB-231 cells with very low cytotoxicity. Stronger selectivity for the IDO1 enzyme (>300-fold) over tryptophan 2,3-dioxygenase (TDO) enzyme was also observed for these compounds. Hence, these fused heterocyclic compounds are attractive candidates for the advanced study of IDO1-dependent cellular function and immunotherapeutic applications.

  12. Selective separation and concentration of antihypertensive peptides from rapeseed protein hydrolysate by electrodialysis with ultrafiltration membranes.

    Science.gov (United States)

    He, Rong; Girgih, Abraham T; Rozoy, Elodie; Bazinet, Laurent; Ju, Xing-Rong; Aluko, Rotimi E

    2016-04-15

    Rapeseed protein isolate was subjected to alcalase digestion to obtain a protein hydrolysate that was separated into peptide fractions using electrodialysis with ultrafiltration membrane (EDUF) technology. The EDUF process (6h duration) led to isolation of three peptide fractions: anionic (recovered in KCl-1 compartment), cationic (recovered in KCl-2 compartment), and those that remained in the feed compartment, which was labeled final rapeseed protein hydrolysate (FRPH). As expected the KCl-1 peptides were enriched in negatively-charged (43.57%) while KCl-2 contained high contents of positively-charged (28.35%) amino acids. All the samples inhibited angiotensin converting enzyme (ACE) and renin activities in dose-dependent manner with original rapeseed protein hydrolysate having the least ACE-inhibitory IC50 value of 0.0932±0.0037 mg/mL while FRPH and KCl-2 had least renin-inhibitory IC50 values of 0.47±0.05 and 0.55±0.06 mg/mL, respectively. Six hours after oral administration (100 mg/kg body weight) to spontaneously hypertensive rats, the FRPH produced the maximum systolic blood pressure reduction of -51 mmHg. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Production of antihypertensive peptides by enzymatic zein hydrolysate from maize-zea mays ssp. mexicana introgression line

    International Nuclear Information System (INIS)

    Wang, L.; Zhang, X.; Qiao, Y.; Qu, M.

    2014-01-01

    Teosintes are essential gene reservoir for maize breeding improvement, among which Zea mays ssp. mexicana has many valuable traits deserved to be transferred into maize genetic background. In this study, one maize-teosinte introgression line SD00100 was selected from the population of Zea mays ssp. mexicana as wild parent. This introgression line manifested the outstanding agricultural traits similar to maize parent Ye 515 and alien genetic material was identified by genomic in situ hybridization (GISH). To produce bioactive peptides with potent angiotensin converting enzyme (ACE) inhibitory activity, zein extracted from endosperm meal was then undergone enzymatic hydrolysis with thermolysin and the hydrolysate was then filtered through a 3 kDa cut-off membrane. ACE inhibitory activity of permeate from Ye 515 and SD00100 was evaluated by RP-HPLC. The IC50 values of the peptides obtained from maize parent and the introgression line were 96.9 micro g/ml and 22.9 micro g/ml, respectively, with significant difference between them. Our results showed that an outstanding inbred maize line was obtained for production of antihypertensive peptides as well as for further development of functional food. (author)

  14. Sacubitril/valsartan: beyond natriuretic peptides.

    Science.gov (United States)

    Singh, Jagdeep S S; Burrell, Louise M; Cherif, Myriam; Squire, Iain B; Clark, Andrew L; Lang, Chim C

    2017-10-01

    Natriuretic peptides, especially B-type natriuretic peptide (BNP), have primarily been regarded as biomarkers in heart failure (HF). However, they are also possible therapeutic agents due to their potentially beneficial physiological effects. The angiotensin receptor-neprilysin inhibitor, sacubitril/valsartan, simultaneously augments the natriuretic peptide system (NPS) by inhibiting the enzyme neprilysin (NEP) and inhibits the renin-angiotensin-aldosterone system (RAAS) by blocking the angiotensin II receptor. It has been shown to improve mortality and hospitalisation outcomes in patients with HF due to left ventricular systolic dysfunction. The key advantage of sacubitril/valsartan has been perceived to be its ability to augment BNP, while its other effects have largely been overlooked. This review highlights the important effects of sacubitril/valsartan, beyond just the augmentation of BNP. First we discuss how NPS physiology differs between healthy individuals and those with HF by looking at mechanisms like the overwhelming effects of RAAS on the NPS, natriuretic peptide receptor desensitisation and absolute natriuretic deficiency. Second, this review explores other hormones that are augmented by sacubitril/valsartan such as bradykinin, substance P and adrenomedullin that may contribute to the efficacy of sacubitril/valsartan in HF. We also discuss concerns that sacubitril/valsartan may interfere with amyloid-β homeostasis with potential implications on Alzheimer's disease and macular degeneration. Finally, we explore the concept of 'autoinhibition' which is a recently described observation that humans have innate NEP inhibitory capability when natriuretic peptide levels rise above a threshold. There is speculation that autoinhibition may provide a surge of natriuretic and other vasoactive peptides to rapidly reverse decompensation. We contend that by pre-emptively inhibiting NEP, sacubitril/valsartan is inducing this surge earlier during decompensation

  15. Potent and Selective BACE-1 Peptide Inhibitors Lower Brain Aβ Levels Mediated by Brain Shuttle Transport

    Directory of Open Access Journals (Sweden)

    Nadine Ruderisch

    2017-10-01

    Full Text Available Therapeutic approaches to fight Alzheimer's disease include anti-Amyloidβ (Aβ antibodies and secretase inhibitors. However, the blood-brain barrier (BBB limits the brain exposure of biologics and the chemical space for small molecules to be BBB permeable. The Brain Shuttle (BS technology is capable of shuttling large molecules into the brain. This allows for new types of therapeutic modalities engineered for optimal efficacy on the molecular target in the brain independent of brain penetrating properties. To this end, we designed BACE1 peptide inhibitors with varying lipid modifications with single-digit picomolar cellular potency. Secondly, we generated active-exosite peptides with structurally confirmed dual binding mode and improved potency. When fused to the BS via sortase coupling, these BACE1 inhibitors significantly reduced brain Aβ levels in mice after intravenous administration. In plasma, both BS and non-BS BACE1 inhibitor peptides induced a significant time- and dose-dependent decrease of Aβ. Our results demonstrate that the BS is essential for BACE1 peptide inhibitors to be efficacious in the brain and active-exosite design of BACE1 peptide inhibitors together with lipid modification may be of therapeutic relevance.

  16. ROCK and PRK-2 Mediate the Inhibitory Effect of Y-27632 on Polyglutamine Aggregation

    Science.gov (United States)

    Shao, Jieya; Welch, William J.; Diamond, Marc I.

    2009-01-01

    Polyglutamine expansion in huntingtin (Htt) and the androgen receptor (AR) causes untreatable neurodegenerative diseases. Y-27632, a therapeutic lead, reduces Htt and AR aggregation in cultured cells, and Htt-induced neurodegeneration in Drosophila. Y-27632 inhibits both Rho-associated kinases ROCK and PRK-2, making its precise intracellular target uncertain. Over-expression of either kinase increases Htt and AR aggregation. Three ROCK inhibitors (Y-27632, H-1077, HA-1152), and a specific ROCK inhibitory peptide reduce polyglutamine protein aggregation, as does knockdown of ROCK or PRK-2 by RNAi. RNAi also indicates that each kinase is required for the inhibitory effects of Y-27632 to manifest fully. These two actin regulatory kinases are thus involved in polyglutamine aggregation, and their simultaneous inhibition may be an important therapeutic goal. PMID:18423405

  17. Peptide Based Radiopharmaceuticals: Specific Construct Approach

    Energy Technology Data Exchange (ETDEWEB)

    Som, P; Rhodes, B A; Sharma, S S

    1997-10-21

    The objective of this project was to develop receptor based peptides for diagnostic imaging and therapy. A series of peptides related to cell adhesion molecules (CAM) and immune regulation were designed for radiolabeling with 99mTc and evaluated in animal models as potential diagnostic imaging agents for various disease conditions such as thrombus (clot), acute kidney failure, and inflection/inflammation imaging. The peptides for this project were designed by the industrial partner, Palatin Technologies, (formerly Rhomed, Inc.) using various peptide design approaches including a newly developed rational computer assisted drug design (CADD) approach termed MIDAS (Metal ion Induced Distinctive Array of Structures). In this approach, the biological function domain and the 99mTc complexing domain are fused together so that structurally these domains are indistinguishable. This approach allows construction of conformationally rigid metallo-peptide molecules (similar to cyclic peptides) that are metabolically stable in-vivo. All the newly designed peptides were screened in various in vitro receptor binding and functional assays to identify a lead compound. The lead compounds were formulated in a one-step 99mTc labeling kit form which were studied by BNL for detailed in-vivo imaging using various animals models of human disease. Two main peptides usingMIDAS approach evolved and were investigated: RGD peptide for acute renal failure and an immunomodulatory peptide derived from tuftsin (RMT-1) for infection/inflammation imaging. Various RGD based metallopeptides were designed, synthesized and assayed for their efficacy in inhibiting ADP-induced human platelet aggregation. Most of these peptides displayed biological activity in the 1-100 µM range. Based on previous work by others, RGD-I and RGD-II were evaluated in animal models of acute renal failure. These earlier studies showed that after acute ischemic injury the renal cortex displays

  18. Cytoplasmic transduction peptide (CTP): New approach for the delivery of biomolecules into cytoplasm in vitro and in vivo

    International Nuclear Information System (INIS)

    Kim, Daeyou; Jeon, Choonju; Kim, Jeong-Hwan; Kim, Mi-Seon; Yoon, Cheol-Hee; Choi, In-Soo; Kim, Sung-Hoon; Bae, Yong-Soo

    2006-01-01

    The protein transduction domain (PTD) of HIV-1 TAT has been extensively documented with regard to its membrane transduction potential, as well as its efficient delivery of biomolecules in vivo. However, the majority of PTD and PTD-conjugated molecules translocate to the nucleus rather than to the cytoplasm after transduction, due to the functional nuclear localization sequence (NLS). Here, we report a cytoplasmic transduction peptide (CTP), which was deliberately designed to ensure the efficient cytoplasmic delivery of the CTP-fused biomolecules. In comparison with PTD, CTP and its fusion partners exhibited a clear preference for cytoplasmic localization, and also markedly enhanced membrane transduction potential. Unlike the mechanism underlying PTD-mediated transduction, CTP-mediated transduction occurs independently of the lipid raft-dependent macropinocytosis pathway. The CTP-conjugated Smac/DIABLO peptide (Smac-CTP) was also shown to be much more efficient than Smac-PTD in the blockage of the antiapoptotic properties of XIAP, suggesting that cytoplasmic functional molecules can be more efficiently targeted by CTP-mediated delivery. In in vivo trafficking studies, CTP-fused β-gal exhibited unique organ tropisms to the liver and lymph nodes when systemically injected into mice, whereas PTD-β-gal exhibited no such tropisms. Taken together, our findings implicate CTP as a novel delivery peptide appropriate for (i) molecular targeting to cytoplasmic compartments in vitro, (ii) the development of class I-associated CTL vaccines, and (iii) special drug delivery in vivo, without causing any untoward effects on nuclear genetic material

  19. Inhibition of duck hepatitis B virus replication by mimic peptides in vitro.

    Science.gov (United States)

    Jia, Hongyu; Liu, Changhong; Yang, Ying; Zhu, Haihong; Chen, Feng; Liu, Jihong; Zhou, Linfu

    2015-11-01

    The aim of the present study was to investigate the inhibitory effect of specific mimic peptides targeting duck hepatitis B virus polymerase (DHBVP) on duck hepatitis B virus (DHBV) replication in primary duck hepatocytes. Phage display technology (PDT) was used to screen for mimic peptides specifically targeting DHBVP and the associated coding sequences were determined using DNA sequencing. The selected mimic peptides were then used to treat primary duck hepatocytes infected with DHBV in vitro. Infected hepatocytes expressing the mimic peptides intracellularly were also prepared. The cells were divided into mimic peptide groups (EXP groups), an entecavir-treated group (positive control) and a negative control group. The medium was changed every 48 h. Following a 10-day incubation, the cell supernatants were collected. DHBV-DNA in the cellular nucleus, cytoplasm and culture supernatant was analyzed by quantitative polymerase chain reaction (qPCR). Eight mimic peptides were selected following three PDT screening rounds for investigation in the DHBV-infected primary duck hepatocytes. The qPCR results showed that following direct treatment with mimic peptide 2 or 7, intracellular expression of mimic peptide 2 or 7, or treatment with entecavir, the DHBV-DNA levels in the culture supernatant and cytoplasm of duck hepatocytes were significantly lower than those in the negative control (Pmimic peptide 7 was lower than that in the other groups (Pmimic peptide 7 was significantly lower than that in the other groups (PMimic peptides specifically targeting DHBVP, administered directly or expressed intracellularly, can significantly inhibit DHBV replication in vitro .

  20. Expression and immunogenicity of M2e peptide of avian influenza virus H5N1 fused to ricin toxin B chain produced in duckweed plants

    Science.gov (United States)

    Firsov, Aleksey; Tarasenko, Irina; Mitiouchkina, Tatiana; Shaloiko, Lyubov; Kozlov, Oleg; Vinokurov, Leonid; Rasskazova, Ekaterina; Murashev, Arkadii; Vainstein, Alexander; Dolgov, Sergey

    2018-02-01

    The amino acid sequence of the extracellular domain of the virus-encoded M2 matrix protein (peptide M2e) is conserved among all subtypes of influenza A strains, enabling the development of a broad-range vaccine against them. We expressed M2e from avian influenza virus A/chicken/Kurgan/5/2005 (H5N1) in nuclear-transformed duckweed plants for further development of an avian influenza vaccine. The 30-amino acid N-terminal fragment of M2, including M2e (denoted M130), was selected for expression. The M2e DNA sequence fused in-frame to the 3’ end of ricin toxin B chain (RTB) was cloned under control of the CaMV 35S promoter into pBI121. The resulting plasmid was used for duckweed transformation, and 23 independent transgenic duckweed lines were obtained. Asialofetuin-binding ELISA of protein samples from the transgenic plants using polyclonal anti-RTB antibodies confirmed the expression of the RTB–M130 fusion protein in 20 lines. Quantitative ELISA of crude protein extracts from these lines showed RTB–M130 accumulation ranging from 0.25–2.5 µg/g fresh weight (0.0006–0.01% of total soluble protein). Affinity chromatography with immobilized asialofetuin and western blot analysis of protein samples from the transgenic plants showed expression of fusion protein RTB–M130 in the dimeric form with a molecular mass of about 70 kDa. Mice were immunized orally with a preparation of total soluble protein from transgenic plants, receiving four doses of 7 μg duckweed-derived RTB–M130 each, with no additional adjuvant. Specific IgG against M2e was detected in immunized mice, and the endpoint titer of anti-M2e IgG was 1024. It was confirmed that oral immunization with RTB-M2e induces production of specific antibodies against peptide M2e, one of the most conserved antigens of the influenza virus. These results may provide further information for the development of a duckweed-based expression system to produce a broad-range edible vaccine against avian influenza.

  1. 'Zipbody' leucine zipper-fused Fab in E. coli in vitro and in vivo expression systems.

    Science.gov (United States)

    Ojima-Kato, Teruyo; Fukui, Kansuke; Yamamoto, Hiroaki; Hashimura, Dai; Miyake, Shiro; Hirakawa, Yuki; Yamasaki, Tomomi; Kojima, Takaaki; Nakano, Hideo

    2016-04-01

    A small antibody fragment, fragment of antigen binding (Fab), is favorable for various immunological assays. However, production efficiency of active Fab in microorganisms depends considerably on the clones. In this study, leucine zipper-peptide pairs that dimerize in parallel (ACID-p1 (LZA)/BASE-p1 (LZB) or c-Jun/c-Fos) were fused to the C-terminus of heavy chain (Hc, VH-CH1) and light chain (Lc, VL-CL), respectively, to accelerate the association of Hc and Lc to form Fab in Escherichia coli in vivo and in vitro expression systems. The leucine zipper-fused Fab named 'Zipbody' was constructed using anti-E. coli O157 monoclonal antibody obtained from mouse hybridoma and produced in both in vitro and in vivo expression systems in an active form, whereas Fab without the leucine zipper fusion was not. Similarly, Zipbody of rabbit monoclonal antibody produced in in vitro expression showed significant activity. The purified, mouse Zipbody produced in the E. coli strain Shuffle T7 Express had specificity toward the antigen; in bio-layer interferometry analysis, the KD value was measured to be 1.5-2.0 × 10(-8) M. These results indicate that leucine zipper fusion to Fab C-termini markedly enhances active Fab formation in E. coli. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  2. Soluble expression and purification of the recombinant bioactive peptide precursor BPP-1 in Escherichia coli using a cELP-SUMO dual fusion system.

    Science.gov (United States)

    Rao, Shengqi; Zang, Xiangyu; Yang, Zhenquan; Gao, Lu; Yin, Yongqi; Fang, Weiming

    2016-02-01

    A bioactive peptide precursor (BPP-1, 14.3 kDa/115AA), a newly designed polypeptide that may exert a potential antihypertensive effect in vivo, is composed of many different ACE inhibitory peptides and antioxidant peptides tandemly linked according to the restriction sites of gastrointestinal proteases. In this report, we present a novel method to obtain soluble BPP-1 in Escherichia coli using cationic elastin-like polypeptide and SUMO (cELP-SUMO) tags. The cELP-SUMO-tagged fusion protein was expressed in soluble form at 20 °C for 20 h. After purification based on the inverse transition cycling (ITC) method, the purified cELP-SUMO-CFPP fusion protein was subsequently cleaved by a SUMO protease to release the mature BPP-1. After a subsequent simple salt precipitation process, approximately 167.2 mg of recombinant BPP-1 was obtained from 1 l of bacterial culture with at least 92% purity. The molecular mass (Mr) of the recombinant BPP-1 was confirmed by MALDI-TOF MS to equal 14,347. The purified BPP-1 was subjected to simulated gastrointestinal digestion, and the resulting hydrolysates exhibited notable ACE inhibitory and antioxidant activities in vitro. This report provides the first description of the soluble production of a bioactive peptide multimer with potential ACE inhibitory and antioxidant activities in E. coli using a cELP-SUMO tag. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Antagonistic effect of disulfide-rich peptide aptamers selected by cDNA display on interleukin-6-dependent cell proliferation

    International Nuclear Information System (INIS)

    Nemoto, Naoto; Tsutsui, Chihiro; Yamaguchi, Junichi; Ueno, Shingo; Machida, Masayuki; Kobayashi, Toshikatsu; Sakai, Takafumi

    2012-01-01

    Highlights: ► Disulfide-rich peptide aptamer inhibits IL-6-dependent cell proliferation. ► Disulfide bond of peptide aptamer is essential for its affinity to IL-6R. ► Inhibitory effect of peptide depends on number and pattern of its disulfide bonds. -- Abstract: Several engineered protein scaffolds have been developed recently to circumvent particular disadvantages of antibodies such as their large size and complex composition, low stability, and high production costs. We previously identified peptide aptamers containing one or two disulfide-bonds as an alternative ligand to the interleukin-6 receptor (IL-6R). Peptide aptamers (32 amino acids in length) were screened from a random peptide library by in vitro peptide selection using the evolutionary molecular engineering method “cDNA display”. In this report, the antagonistic activity of the peptide aptamers were examined by an in vitro competition enzyme-linked immunosorbent assay (ELISA) and an IL-6-dependent cell proliferation assay. The results revealed that a disulfide-rich peptide aptamer inhibited IL-6-dependent cell proliferation with similar efficacy to an anti-IL-6R monoclonal antibody.

  4. 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.

  5. CLE peptides regulate lateral root development in response to nitrogen nutritional status of plants.

    Science.gov (United States)

    Araya, Takao; von Wirén, Nicolaus; Takahashi, Hideki

    2014-01-01

    CLE (CLAVATA3/embryo surrounding region (ESR)) peptides control meristem functions in plants. Our recent study highlights the critical role of a peptide-receptor signaling module composed of nitrogen (N)-responsive CLE peptides and the CLAVATA1 (CLV1) leucine-rich repeat receptor-like kinase in controlling lateral root development in Arabidopsis thaliana. CLE1, -3, -4 and -7 are expressed in root pericycle cells in Arabidopsis roots under N-limited growth conditions. Overexpression of these CLE genes inhibits lateral root emergence from the primary root. The inhibitory action of N-responsive CLE peptides on lateral root development requires the function of CLV1 expressed in phloem companion cells in roots, suggesting that downstream signals are transferred through phloem for systemic regulation of root system architecture. An additional mechanism downstream of CLV1 feedback-regulates transcript levels of N-responsive CLE genes in roots for fine-tuning the signal amplitude.

  6. Computational model of exploding metallic fuses for multimegajoule switching

    International Nuclear Information System (INIS)

    Lindemuth, I.R.; Brownell, J.H.; Greene, A.E.; Nickel, G.H.; Oliphant, T.A.; Weiss, D.L.

    1985-01-01

    A new model for determining the time-dependent behavior of exploding metallic fuses is formulated. The model draws on an atomic data base and gives insight into the temporal behavior of the material density and temperature of the fuse as well as the nonlinear electrical circuit interaction. The model includes an embedding insulating tamper and leads to a plausible explanation of fuse ''restrike.'' The model predicts time-scale compression of 500 for inductive store systems powered by explosive driven magnetic flux compression generators. A scenario for achieving multimegajoule foil implosions is predicted

  7. Bilateral maxillary fused second and third molars: a rare occurrence.

    Science.gov (United States)

    Liang, Rui-Zhen; Wu, Jin-Tao; Wu, You-Nong; Smales, Roger J; Hu, Ming; Yu, Jin-Hua; Zhang, Guang-Dong

    2012-12-01

    This case report describes the diagnosis and endodontic therapy of maxillary fused second and third molars, using cone-beam computed tomography (CBCT). A 31-year-old Chinese male, with no contributory medical or family/social history, presented with throbbing pain in the maxillary right molar area following an unsuccessful attempted tooth extraction. Clinical examination revealed what appeared initially to be a damaged large extra cusp on the buccal aspect of the distobuccal cusp of the second molar. However, CBCT revealed that a third molar was fused to the second molar. Unexpectedly, the maxillary left third molar also was fused to the second molar, and the crown of an unerupted supernumerary fourth molar was possibly also fused to the apical root region of the second molar. Operative procedures should not be attempted without adequate radiographic investigation. CBCT allowed the precise location of the root canals of the right maxillary fused molar teeth to permit successful endodontic therapy, confirmed after 6 months.

  8. Quantification of Residual Stress from Photonic Signatures of Fused Silica

    Science.gov (United States)

    Cramer, K. Elliott; Hayward, Maurice; Yost, William E.

    2013-01-01

    A commercially available grey-field polariscope (GFP) instrument for photoelastic examination is used to assess impact damage inflicted upon the outer-most pane of Space Shuttle windows made from fused silica. A method and apparatus for calibration of the stress-optic coefficient using four-point bending is discussed. The results are validated on known material (acrylic) and are found to agree with literature values to within 6%. The calibration procedure is then applied to fused-silica specimens and the stress-optic coefficient is determined to be 2.43 +/- 0.54 x 10(exp -12)/Pa. Fused silica specimens containing impacts artificially made at NASA's Hypervelocity Impact Technology Facility (HIT-F), to simulate damage typical during space flight, are examined. The damage sites are cored from fused silica window carcasses and examined with the GFP. The calibrated GFP measurements of residual stress patterns surrounding the damage sites are presented. Keywords: Glass, fused silica, photoelasticity, residual stress

  9. Fiber fuse behavior in kW-level continuous-wave double-clad field laser

    International Nuclear Information System (INIS)

    Sun Jun-Yi; Xiao Qi-Rong; Li Dan; Wang Xue-Jiao; Zhang Hai-Tao; Gong Ma-Li; Yan Ping

    2016-01-01

    In this study, original experimental data for fiber fuse in kW-level continuous-wave (CW) high power double-clad fiber (DCF) laser are reported. The propagating velocity of the fuse is 9.68 m/s in a 3.1-kW Yb-doped DCF laser. Three other cases in Yb-doped DCF are also observed. We think that the ignition of fiber fuse is caused by thermal mechanism, and the formation of bullet-shaped tracks is attributed to the optical discharge and temperature gradient. The inducements of initial fuse and formation of bullet-shaped voids are analyzed. This investigation of fiber fuse helps better understand the fiber fuse behavior, in order to avoid the catastrophic destruction caused by fiber fuse in high power fiber laser. (paper)

  10. Inhibition of HIV-1 infection by synthetic peptides derived CCR5 fragments

    International Nuclear Information System (INIS)

    Imai, Masaki; Baranyi, Lajos; Okada, Noriko; Okada, Hidechika

    2007-01-01

    HIV-1 infection requires interaction of viral envelope protein gp160 with CD4 and a chemokine receptor, CCR5 or CXCR4 as entry coreceptor. We designed HIV-inhibitory peptides targeted to CCR5 using a novel computer program (ANTIS), which searched all possible sense-antisense amino acid pairs between proteins. Seven AHBs were found in CCR5 receptor. All AHB peptides were synthesized and tested for their ability to prevent HIV-1 infection to human T cells. A peptide fragment (LC5) which is a part of the CCR5 receptor corresponding to the loop between the fifth and sixth transmembrane regions (amino acids 222-240) proved to inhibit HIV-1 IIIB infection of MT-4 cells. Interaction of these antisense peptides could be involved in sustaining HIV-1 infectivity. LC5 effectively indicated dose-dependent manner, and the suppression was enhanced additively by T20 peptide, which inhibits infection in vitro by disrupting the gp41 conformational changes necessary for membrane fusion. Thus, these results indicate that CCR5-derived AHB peptides could provide a useful tool to define the mechanism(s) of HIV infection, and may provide insight which will contribute to the development of an anti-HIV-1 reagent

  11. Fuse and application of said fuse to the construction of an emergency shutdown system for a nuclear reactor

    International Nuclear Information System (INIS)

    Taulier, H.H.L.; Brugeille, G.

    1978-01-01

    A fuse device for an automatic emergency shutdown system in fast reactors provides a coupling between a casing tube placed within a fuel can and a series of neutron-absorbing masses held together above the reactor core under normal operating conditions but released in free fall to the lower portion of the casing tube at the level of the reactor core as a result of melting of the fuse when operating characteristics such as temperature or neutron flux attain a level which exceeds a predetermined threshold

  12. Fuse and application of said fuse to the construction of an emergency shutdown system for a nuclear reactor

    International Nuclear Information System (INIS)

    Taulier, H.H.L.; Brugeilles, G.

    1976-01-01

    A fuse device for an automatic emergency shutdown system in fast reactors provides a coupling between a casing tube placed within a fuel can and a series of neutron-absorbing masses held together above the reactor core under normal operating conditions. They are released in free fall to the lower portion of the casing tube at the level of the reactor core as a result of melting of the fuse when operating characteristics such as temperature or neutron flux attain a level which exceeds a predetermined threshold

  13. and 8-Membered Oxygen-containing Benzo-fused Rings using ...

    African Journals Online (AJOL)

    NJD

    A number of benzo-fused oxygen-containing heterocycles were synthesized from allyl-3-isopropoxy-4-methoxybenzaldehyde using metathesis or an alkene isomerization-metathesis sequence as key synthetic steps. Benzo-fused compounds thus formed included a 3,6-dihydro-1H-2-benzoxocine, ...

  14. Mechanism of papain-catalyzed synthesis of oligo-tyrosine peptides.

    Science.gov (United States)

    Mitsuhashi, Jun; Nakayama, Tsutomu; Narai-Kanayama, Asako

    2015-01-01

    Di-, tri-, and tetra-tyrosine peptides with angiotensin I-converting enzyme inhibitory activity were synthesized by papain-catalyzed polymerization of L-tyrosine ethyl ester in aqueous media at 30 °C. Varying the reaction pH from 6.0 to 7.5 and the initial concentration of the ester substrate from 25 to 100 mM, the highest yield of oligo-tyrosine peptides (79% on a substrate basis) was produced at pH 6.5 and 75 mM, respectively. In the reaction initiated with 100 mM of the substrate, approx. 50% yield of insoluble, highly polymerized peptides accumulated. At less than 15 mM, the reaction proceeded poorly; however, from 30 mM to 120 mM a dose-dependent increase in the consumption rate of the substrate was observed with a sigmoidal curve. Meanwhile, each of the tri- and tetra-tyrosine peptides, even at approx. 5mM, was consumed effectively by papain but was not elongated to insoluble polymers. For deacylation of the acyl-papain intermediate through which a new peptide bond is made, L-tyrosine ethyl ester, even at 5mM, showed higher nucleophilic activity than di- and tri-tyrosine. These results indicate that the mechanism through which papain polymerizes L-tyrosine ethyl ester is as follows: the first interaction between papain and the ester substrate is a rate-limiting step; oligo-tyrosine peptides produced early in the reaction period are preferentially used as acyl donors, while the initial ester substrate strongly contributes as a nucleophile to the elongation of the peptide product; and the balance between hydrolytic fragmentation and further elongation of oligo-tyrosine peptides is dependent on the surrounding concentration of the ester substrate. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Gonadotropin Inhibitory Hormone Down-Regulates the Brain-Pituitary Reproductive Axis of Male European Sea Bass (Dicentrarchus labrax).

    Science.gov (United States)

    Paullada-Salmerón, José A; Cowan, Mairi; Aliaga-Guerrero, María; Morano, Francesca; Zanuy, Silvia; Muñoz-Cueto, José A

    2016-06-01

    Gonadotropin-inhibitory hormone (GnIH) inhibits gonadotropin synthesis and release from the pituitary of birds and mammals. However, the physiological role of orthologous GnIH peptides on the reproductive axis of fish is still uncertain, and their actions on the main neuroendocrine systems controlling reproduction (i.e., GnRHs, kisspeptins) have received little attention. In a recent study performed in the European sea bass, we cloned a cDNA encoding a precursor polypeptide that contained C-terminal MPMRFamide (sbGnIH-1) and MPQRFamide (sbGnIH-2) peptide sequences, developed a specific antiserum against sbGnIH-2, and characterized its central and pituitary GnIH projections in this species. In this study, we analyzed the effects of intracerebroventricular injection of sbGnIH-1 and sbGnIH-2 on brain and pituitary expression of reproductive hormone genes (gnrh1, gnrh2, gnrh3, kiss1, kiss2, gnih, lhbeta, fshbeta), and their receptors (gnrhr II-1a, gnrhr II-2b, kiss1r, kiss2r, and gnihr) as well as on plasma Fsh and Lh levels. In addition, we determined the effects of GnIH on pituitary somatotropin (Gh) expression. The results obtained revealed the inhibitory role of sbGnIH-2 on brain gnrh2, kiss1, kiss2, kiss1r, gnih, and gnihr transcripts and on pituitary fshbeta, lhbeta, gh, and gnrhr-II-1a expression, whereas sbGnIH-1 only down-regulated brain gnrh1 expression. However, at different doses, central administration of both sbGnIH-1 and sbGnIH-2 decreased Lh plasma levels. Our work represents the first study reporting the effects of centrally administered GnIH in fish and provides evidence of the differential actions of sbGnIH-1 and sbGnIH-2 on the reproductive axis of sea bass, the main inhibitory role being exerted by the sbGnIH-2 peptide. © 2016 by the Society for the Study of Reproduction, Inc.

  16. Construction of hybrid peptide synthetases by module and domain fusions.

    Science.gov (United States)

    Mootz, H D; Schwarzer, D; Marahiel, M A

    2000-05-23

    Nonribosomal peptide synthetases are modular enzymes that assemble peptides of diverse structures and important biological activities. Their modular organization provides a great potential for the rational design of novel compounds by recombination of the biosynthetic genes. Here we describe the extension of a dimodular system to trimodular ones based on whole-module fusion. The recombinant hybrid enzymes were purified to monitor product assembly in vitro. We started from the first two modules of tyrocidine synthetase, which catalyze the formation of the dipeptide dPhe-Pro, to construct such hybrid systems. Fusion of the second, proline-specific module with the ninth and tenth modules of the tyrocidine synthetases, specific for ornithine and leucine, respectively, resulted in dimodular hybrid enzymes exhibiting the combined substrate specificities. The thioesterase domain was fused to the terminal module. Upon incubation of these dimodular enzymes with the first tyrocidine module, TycA, incorporating dPhe, the predicted tripeptides dPhe-Pro-Orn and dPhe-Pro-Leu were obtained at rates of 0.15 min(-1) and 2.1 min(-1). The internal thioesterase domain was necessary and sufficient to release the products from the hybrid enzymes and thereby facilitate a catalytic turnover. Our approach of whole-module fusion is based on an improved definition of the fusion sites and overcomes the recently discovered editing function of the intrinsic condensation domains. The stepwise construction of hybrid peptide synthetases from catalytic subunits reinforces the inherent potential for the synthesis of novel, designed peptides.

  17. Peptide chemistry toolbox - Transforming natural peptides into peptide therapeutics.

    Science.gov (United States)

    Erak, Miloš; Bellmann-Sickert, Kathrin; Els-Heindl, Sylvia; Beck-Sickinger, Annette G

    2018-06-01

    The development of solid phase peptide synthesis has released tremendous opportunities for using synthetic peptides in medicinal applications. In the last decades, peptide therapeutics became an emerging market in pharmaceutical industry. The need for synthetic strategies in order to improve peptidic properties, such as longer half-life, higher bioavailability, increased potency and efficiency is accordingly rising. In this mini-review, we present a toolbox of modifications in peptide chemistry for overcoming the main drawbacks during the transition from natural peptides to peptide therapeutics. Modifications at the level of the peptide backbone, amino acid side chains and higher orders of structures are described. Furthermore, we are discussing the future of peptide therapeutics development and their impact on the pharmaceutical market. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. Identification of diphtheria toxin R domain mutants with enhanced inhibitory activity against HB-EGF.

    Science.gov (United States)

    Suzuki, Keisuke; Mizushima, Hiroto; Abe, Hiroyuki; Iwamoto, Ryo; Nakamura, Haruki; Mekada, Eisuke

    2015-05-01

    Heparin-binding epidermal growth factor-like growth factor (HB-EGF), a ligand of EGF receptor, is involved in the growth and malignant progression of cancers. Cross-reacting material 197, CRM197, a non-toxic mutant of diphtheria toxin (DT), specifically binds to the EGF-like domain of HB-EGF and inhibits its mitogenic activity, thus CRM197 is currently under evaluation in clinical trials for cancer therapy. To develop more potent DT mutants than CRM197, we screened various mutant proteins of R domain of DT, the binding site for HB-EGF. A variety of R-domain mutant proteins fused with maltose-binding protein were produced and their inhibitory activity was evaluated in vitro. We found four R domain mutants that showed much higher inhibitory activity against HB-EGF than wild-type (WT) R domain. These R domain mutants suppressed HB-EGF-dependent cell proliferation more effectively than WT R domain. Surface plasmon resonance revealed their higher affinity to HB-EGF than WT R domain. CRM197(R460H) carrying the newly identified mutation showed increased cell proliferation inhibitory activity and affinity to HB-EGF. These results suggest that CRM197(R460H) or other recombinant proteins carrying newly identified mutation(s) in the R domain are potential therapeutics targeting HB-EGF. © The Authors 2014. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

  19. A novel chimeric cell-penetrating peptide with membrane-disruptive properties for efficient endosomal escape.

    Science.gov (United States)

    Salomone, Fabrizio; Cardarelli, Francesco; Di Luca, Mariagrazia; Boccardi, Claudia; Nifosì, Riccardo; Bardi, Giuseppe; Di Bari, Lorenzo; Serresi, Michela; Beltram, Fabio

    2012-11-10

    Efficient endocytosis into a wide range of target cells and low toxicity make the arginine-rich Tat peptide (Tat(11): YGRKKRRQRRR, residues 47-57 of HIV-1 Tat protein) an excellent transporter for delivery purposes. Unfortunately, molecules taken up by endocytosis undergo endosomal entrapment and possible metabolic degradation. Escape from the endosome is therefore actively researched. In this context, antimicrobial peptides (AMPs) provide viable templates for the design of new membrane-disruptive motifs. In particular the Cecropin-A and Melittin hybrids (CMs) are among the smallest and most effective peptides with membrane-perturbing abilities. Here we present a novel chimeric peptide in which the Tat(11) motif is fused to the CM(18) hybrid (KWKLFKKIGAVLKVLTTG, residues 1-7 of Cecropin-A and 2-12 of Melittin). When administered to cells, CM(18)-Tat(11) combines the two desired functionalities: efficient uptake and destabilization of endocytotic-vesicle membranes. We show that this chimeric peptide effectively increases cargo-molecule cytoplasm availability and allows the subsequent intracellular localization of diverse membrane-impermeable molecules (i.e. Tat(11)-EGFP fusion protein, calcein, dextrans, and plasmidic DNA) with no detectable cytotoxicity. The present results open the way to the rational engineering of "modular" cell-penetrating peptides (CPPs) that combine (i) efficient translocation from the extracellular milieu into vesicles and (ii) efficient release of molecules from vesicles into the cytoplasm. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Outbursts In Symbiotic Binaries (FUSE 2000)

    Science.gov (United States)

    Kenyon, Scott J.; Sonneborn, George (Technical Monitor)

    2002-01-01

    During the past year, we made good progress on analysis of FUSE observations of the symbiotic binary Z And. For background, Z And is a binary system composed of a red giant and a hot component of unknown status. The orbital period is roughly 750 days. The hot component undergoes large-scale eruptions every 10-20 yr. An outburst began several years ago, triggering this FUSE opportunity. First, we obtained an excellent set of ground-based optical data in support, of the FUSE observations. We used FAST, a high throughput low resolution spectrograph on the 1.5-m telescope at Mt. Hopkins, Arizona. A 300 g/ mm grating blazed at 4750 A, a 3 in. slit, and a thinned Loral 512 x 2688 CCD gave us spectra covering 3800-7500 A at a resolution of 6 A. The wavelength solution for each spectrum has a probable error of +/- 0.5 A or better. Most of the resulting spectra have moderate signal-to-noise, S/.N approx. greater than 30 per pixel. The time coverage for these spectra is excellent. Typically, we acquired spectra every 1-2 nights during dark runs at Mt. Hopkins. These data cover most of the rise and all of the decline of the recent outburst. The spectra show a wealth of emission lines, including H I, He I, He II, [Fe V11], and the Raman scattering bands at 6830 A and 7088 A. The Raman bands and other high ionization features vary considerably throughout the outburst. These features will enable us to correlate variations in the FUSE spectra with variations in the optical spectra. Second, we began an analysis of FUSE spectra of Z And. We have carefully examined the spectra, identifying real features and defects. We have identified and measured fluxes for all strong emission lines, including the O VI doublet at 1032 A and 1038 A. These and several other strong emission lines display pronounced P Cygni absorption components indicative of outgrowing gas. We will attempt to correlate these velocities with similar profiles observed on optical spectra. The line velocities - together

  1. ELIMINATING NEGETIVE EFFECT OF INVERTER-BASED DGs ON FUSE-RECLOSER COORDINATION IN DISTRIBUTION SYSTEMS

    OpenAIRE

    shakarami, mahmoudreza; namdari, farhad; salehi, moslem

    2015-01-01

    Despite many advantages of distributed generation (DG) sources, they may have a negative effect on the protection of distribution systems. In a distribution system, fuse-recloser protection scheme is designed such that the recloser could operate faster than the fuse to prevent fuse burning; but, the presence of DGs in fault conditions may lead to increased fuse current and thus faster performance of the fuse than the recloser and lack of coordination. In this paper, effect of DGs on fuse-recl...

  2. 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.

  3. Fusing Facial Features for Face Recognition

    Directory of Open Access Journals (Sweden)

    Jamal Ahmad Dargham

    2012-06-01

    Full Text Available Face recognition is an important biometric method because of its potential applications in many fields, such as access control, surveillance, and human-computer interaction. In this paper, a face recognition system that fuses the outputs of three face recognition systems based on Gabor jets is presented. The first system uses the magnitude, the second uses the phase, and the third uses the phase-weighted magnitude of the jets. The jets are generated from facial landmarks selected using three selection methods. It was found out that fusing the facial features gives better recognition rate than either facial feature used individually regardless of the landmark selection method.

  4. In silico panning for a non-competitive peptide inhibitor

    Directory of Open Access Journals (Sweden)

    Ikebukuro Kazunori

    2007-01-01

    Full Text Available Abstract Background Peptide ligands have tremendous therapeutic potential as efficacious drugs. Currently, more than 40 peptides are available in the market for a drug. However, since costly and time-consuming synthesis procedures represent a problem for high-throughput screening, novel procedures to reduce the time and labor involved in screening peptide ligands are required. We propose the novel approach of 'in silico panning' which consists of a two-stage screening, involving affinity selection by docking simulation and evolution of the peptide ligand using genetic algorithms (GAs. In silico panning was successfully applied to the selection of peptide inhibitor for water-soluble quinoprotein glucose dehydrogenase (PQQGDH. Results The evolution of peptide ligands for a target enzyme was achieved by combining a docking simulation with evolution of the peptide ligand using genetic algorithms (GAs, which mimic Darwinian evolution. Designation of the target area as next to the substrate-binding site of the enzyme in the docking simulation enabled the selection of a non-competitive inhibitor. In all, four rounds of selection were carried out on the computer; the distribution of the docking energy decreased gradually for each generation and improvements in the docking energy were observed over the four rounds of selection. One of the top three selected peptides with the lowest docking energy, 'SERG' showed an inhibitory effect with Ki value of 20 μM. PQQGDH activity, in terms of the Vmax value, was 3-fold lower than that of the wild-type enzyme in the presence of this peptide. The mechanism of the SERG blockage of the enzyme was identified as non-competitive inhibition. We confirmed the specific binding of the peptide, and its equilibrium dissociation constant (KD value was calculated as 60 μM by surface plasmon resonance (SPR analysis. Conclusion We demonstrate an effective methodology of in silico panning for the selection of a non

  5. Bioaccessible peptides released by in vitro gastrointestinal digestion of fermented goat milks.

    Science.gov (United States)

    Moreno-Montoro, Miriam; Jauregi, Paula; Navarro-Alarcón, Miguel; Olalla-Herrera, Manuel; Giménez-Martínez, Rafael; Amigo, Lourdes; Miralles, Beatriz

    2018-06-01

    In this study, ultrafiltered goat milks fermented with the classical starter bacteria Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarus subsp. thermophilus or with the classical starter plus the Lactobacillus plantarum C4 probiotic strain were analyzed using ultra-high performance liquid chromatography-quadrupole-time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS) and/or high performance liquid chromatography-ion trap (HPLC-IT-MS/MS). Partial overlapping of the identified sequences with regard to fermentation culture was observed. Evaluation of the cleavage specificity suggested a lower proteolytic activity of the probiotic strain. Some of the potentially identified peptides had been previously reported as angiotensin-converting enzyme (ACE) inhibitory, antioxidant, and antibacterial and might account for the in vitro activity previously reported for these fermented milks. Simulated digestion of the products was conducted in the presence of a dialysis membrane to retrieve the bioaccessible peptide fraction. Some sequences with reported physiological activity resisted digestion but were found in the non-dialyzable fraction. However, new forms released by digestion, such as the antioxidant α s1 -casein 144 YFYPQL 149 , the antihypertensive α s2 -casein 90 YQKFPQY 96 , and the antibacterial α s2 -casein 165 LKKISQ 170 , were found in the dialyzable fraction of both fermented milks. Moreover, in the fermented milk including the probiotic strain, the k-casein dipeptidyl peptidase IV inhibitor (DPP-IV) 51 INNQFLPYPY 60 as well as additional ACE inhibitory or antioxidant sequences could be identified. With the aim of anticipating further biological outcomes, quantitative structure activity relationship (QSAR) analysis was applied to the bioaccessible fragments and led to potential ACE inhibitory sequences being proposed. Graphical abstract Ultrafiltered goat milks were fermented with the classical starter bacteria (St) and with St plus the

  6. In vitro and in vivo delivery of therapeutic proteins using cell penetrating peptides.

    Science.gov (United States)

    Bolhassani, Azam; Jafarzade, Behnaz Sadat; Mardani, Golnaz

    2017-01-01

    The failure of proteins to penetrate mammalian cells or target tumor cells restricts their value as therapeutic tools in a variety of diseases such as cancers. Recently, protein transduction domains (PTDs) or cell penetrating peptides (CPPs) have been shown to promote the delivery of therapeutic proteins or peptides into live cells. The successful delivery of proteins mainly depends on their physicochemical properties. Although, linear cell penetrating peptides are one of the most effective delivery vehicles; but currently, cyclic CPPs has been developed to potently transport bioactive full-length proteins into cells. Up to now, several small protein transduction domains from viral proteins including Tat or VP22 could be fused to other peptides or proteins to entry them in various cell types at a dose-dependent approach. A major disadvantage of PTD-fusion proteins is primary uptake into endosomal vesicles leading to inefficient release of the fusion proteins into the cytosol. Recently, non-covalent complex formation (Chariot) between proteins and CPPs has attracted a special interest to overcome some delivery limitations (e.g., toxicity). Many preclinical and clinical trials of CPP-based delivery are currently under evaluation. Generally, development of more efficient protein transduction domains would significantly increase the potency of protein therapeutics. Moreover, the synergistic or combined effects of CPPs with other delivery systems for protein/peptide drug delivery would promote their therapeutic effects in cancer and other diseases. In this review, we will describe the functions and implications of CPPs for delivering the therapeutic proteins or peptides in preclinical and clinical studies. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Thiomers: potential excipients for non-invasive peptide delivery systems.

    Science.gov (United States)

    Bernkop-Schnürch, Andreas; Krauland, Alexander H; Leitner, Verena M; Palmberger, Thomas

    2004-09-01

    In recent years thiolated polymers or so-called thiomers have appeared as a promising alternative in the arena of non-invasive peptide delivery. Thiomers are generated by the immobilisation of thiol-bearing ligands to mucoadhesive polymeric excipients. By formation of disulfide bonds with mucus glycoproteins, the mucoadhesive properties of these polymers are improved up to 130-fold. Due to formation of inter- and intramolecular disulfide bonds within the thiomer itself, dosage forms such as tablets or microparticles display strong cohesive properties resulting in comparatively higher stability, prolonged disintegration times and a more controlled release of the embedded peptide drug. The permeation of peptide drugs through mucosa can be improved by the use of thiolated polymers. Additionally some thiomers exhibit improved inhibitory properties towards peptidases. The efficacy of thiomers in non-invasive peptide delivery could be demonstrated by various in vivo studies. Tablets comprising a thiomer and pegylated insulin, for instance, resulted in a pharmacological efficacy of 7% after oral application to diabetic mice. Furthermore, a pharmacological efficacy of 1.3% was achieved in rats by oral administration of calcitonin tablets comprising a thiomer. Human growth hormone in a thiomer-gel was applied nasally to rats and led to a bioavailability of 2.75%. In all these studies, formulations comprising the corresponding unmodified polymer had only a marginal or no effect. According to these results drug carrier systems based on thiomers seem to be a promising tool for non-invasive peptide drug delivery.

  8. The PDB database is a rich source of alpha-helical anti-microbial peptides to combat disease causing pathogens [version 2; referees: 2 approved, 1 approved with reservations

    Directory of Open Access Journals (Sweden)

    Sandeep Chakraborty

    2015-06-01

    Full Text Available The therapeutic potential of α-helical anti-microbial peptides (AH-AMP to combat pathogens is fast gaining prominence. Based on recently published open access software for characterizing α-helical peptides (PAGAL, we elucidate a search methodology (SCALPEL that leverages the massive structural data pre-existing in the PDB database to obtain AH-AMPs belonging to the host proteome. We provide in vitro validation of SCALPEL on plant pathogens (Xylella fastidiosa, Xanthomonas arboricola and Liberibacter crescens by identifying AH-AMPs that mirror the function and properties of cecropin B, a well-studied AH-AMP. The identified peptides include a linear AH-AMP present within the existing structure of phosphoenolpyruvate carboxylase (PPC20, and an AH-AMP mimicing the properties of the two α-helices of cecropin B from chitinase (CHITI25. The minimum inhibitory concentration of these peptides are comparable to that of cecropin B, while anionic peptides used as control failed to show any inhibitory effect on these pathogens. Substitute therapies in place of conventional chemotherapies using membrane permeabilizing peptides like these might also prove effective to target cancer cells. The use of native structures from the same organism could possibly ensure that administration of such peptides will be better tolerated and not elicit an adverse immune response. We suggest a similar approach to target Ebola epitopes, enumerated using PAGAL recently, by selecting suitable peptides from the human proteome, especially in wake of recent reports of cationic amphiphiles inhibiting virus entry and infection.

  9. Hole-assisted fiber based fiber fuse terminator supporting 22 W input

    Science.gov (United States)

    Tsujikawa, Kyozo; Kurokawa, Kenji; Hanzawa, Nobutomo; Nozoe, Saki; Matsui, Takashi; Nakajima, Kazuhide

    2018-05-01

    We investigated the air hole structure in hole-assisted fiber (HAF) with the aim of terminating fiber fuse propagation. We focused on two structural parameters c/MFD and S1/S2, which are related respectively to the position and area of the air holes, and mapped their appropriate values for terminating fiber fuse propagation. Here, MFD is the mode field diameter, c is the diameter of an inscribed circle linking the air holes, S1 is the total area of the air holes, and S2 is the area of a circumscribed circle linking the air holes. On the basis of these results, we successfully realized a compact fiber fuse terminator consisting of a 1.35 mm-long HAF, which can terminate fiber fuse propagation even with a 22 W input. In addition, we observed fiber fuse termination using a high-speed camera. We additionally confirmed that the HAF-based fiber fuse terminator is effective under various input power conditions. The penetration length of the optical discharge in the HAF was only less than 300 μm when the input power was from 2 to 22 W.

  10. Fused upper central incisors: management of two clinical cases.

    Science.gov (United States)

    Sfasciotti, Gian Luca; Marini, Roberta; Bossù, Maurizio; Ierardo, Gaetano; Annibali, Susanna

    2011-03-01

    This paper reports the management of two clinical cases, in which the upper right central incisor was fused with a supernumerary tooth and the upper left central incisor was macrodontic. A radiographic examination revealed that the fused teeth had two separate roots. Hemisectioning of the fused teeth was performed, the supernumerary portion was extracted and the remaining part was reshaped to remove any sharp margins and to achieve a normal morphology. The macrodontic central incisors were not treated. At 12-months post-surgery there were no periodontal problems and no hypersensitivity. Orthodontic treatment was performed to appropriately align the maxillary teeth and to correct the malocclusion.

  11. A Journey through the Gonadotropin-Inhibitory Hormone System of Fish

    Directory of Open Access Journals (Sweden)

    José A. Muñoz-Cueto

    2017-10-01

    Full Text Available Gonadotropin-inhibitory hormone (GnIH is a hypothalamic neuropeptide that belongs to the RFamide peptide family and was first identified in the quail brain. From the discovery of avian GnIH, orthologous GnIH peptides have been reported in a variety of vertebrates, including mammals, amphibians, teleosts and agnathans, but also in protochordates. It has been clearly established that GnIH suppresses reproduction in avian and mammalian species through its inhibitory actions on brain GnRH and pituitary gonadotropins. In addition, GnIH also appears to be involved in the regulation of feeding, growth, stress response, heart function and social behavior. These actions are mediated via G protein-coupled GnIH receptors (GnIH-Rs, of which two different subtypes, GPR147 and GPR74, have been described to date. With around 30,000 species, fish represent more than one-half of the total number of recognized living vertebrate species. In addition to this impressive biological diversity, fish are relevant because they include model species with scientific and clinical interest as well as many exploited species with economic importance. In spite of this, the study of GnIH and its physiological effects on reproduction and other physiological processes has only been approached in a few fish species, and results obtained are in some cases conflicting. In this review, we summarize the information available in the literature on GnIH sequences identified in fish, the distribution of GnIH and GnIH-Rs in central and peripheral tissues, the physiological actions of GnIH on the reproductive brain-pituitary-gonadal axis, as well as other reported effects of this neuropeptide, and existing knowledge on the regulatory mechanisms of GnIH in fish.

  12. [Effects of laser welding on bond of porcelain fused cast pure titanium].

    Science.gov (United States)

    Zhu, Juan-fang; He, Hui-ming; Gao, Bo; Wang, Zhong-yi

    2006-04-01

    To investigate the influence of the laser welding on bond of porcelain fused to cast pure titanium. Twenty cast titanium plates were divided into two groups: laser welded group and control group. The low-fusing porcelain was fused to the laser welded cast pure titanium plates at fusion zone. The bond strength of the porcelain to laser welded cast pure titanium was measured by the three-point bending test. The interface of titanium and porcelain was investigated by scanning electron microscopy (SEM) and energy depressive X-ray detector (EDX). The non-welded titanium plates were used as comparison. No significant difference of the bond strength was found between laser-welded samples [(46.85 +/- 0.76) MPa] and the controls [(41.71 +/- 0.55) MPa] (P > 0.05). The SEM displayed the interface presented similar irregularities with a predominance. The titanium diffused to low-fusing porcelain, while silicon and aluminum diffused to titanium basement. Laser welding does not affect low-fusing porcelain fused to pure titanium.

  13. Renal cell carcinoma in patient with crossed fused renal ectopia

    Directory of Open Access Journals (Sweden)

    Ozgur Cakmak

    2016-01-01

    Full Text Available Primary renal cell carcinomas have rarely been reported in patients with crossed fused renal ectopia. We presented a patient with right to left crossed fused kidney harbouring renal tumor. The most frequent tumor encountered in crossed fused renal ectopia is renal cell carcinoma. In this case, partial nephrectomy was performed which pave way to preservation of the uninvolved both renal units. Due to unpredictable anatomy, careful preoperative planning and meticulous delineation of renal vasculature is essential for preservation of the uninvolved renal units.

  14. Effect of signal peptide on stability and folding of Escherichia coli thioredoxin.

    Directory of Open Access Journals (Sweden)

    Pranveer Singh

    Full Text Available The signal peptide plays a key role in targeting and membrane insertion of secretory and membrane proteins in both prokaryotes and eukaryotes. In E. coli, recombinant proteins can be targeted to the periplasmic space by fusing naturally occurring signal sequences to their N-terminus. The model protein thioredoxin was fused at its N-terminus with malE and pelB signal sequences. While WT and the pelB fusion are soluble when expressed, the malE fusion was targeted to inclusion bodies and was refolded in vitro to yield a monomeric product with identical secondary structure to WT thioredoxin. The purified recombinant proteins were studied with respect to their thermodynamic stability, aggregation propensity and activity, and compared with wild type thioredoxin, without a signal sequence. The presence of signal sequences leads to thermodynamic destabilization, reduces the activity and increases the aggregation propensity, with malE having much larger effects than pelB. These studies show that besides acting as address labels, signal sequences can modulate protein stability and aggregation in a sequence dependent manner.

  15. Effect of signal peptide on stability and folding of Escherichia coli thioredoxin.

    Science.gov (United States)

    Singh, Pranveer; Sharma, Likhesh; Kulothungan, S Rajendra; Adkar, Bharat V; Prajapati, Ravindra Singh; Ali, P Shaik Syed; Krishnan, Beena; Varadarajan, Raghavan

    2013-01-01

    The signal peptide plays a key role in targeting and membrane insertion of secretory and membrane proteins in both prokaryotes and eukaryotes. In E. coli, recombinant proteins can be targeted to the periplasmic space by fusing naturally occurring signal sequences to their N-terminus. The model protein thioredoxin was fused at its N-terminus with malE and pelB signal sequences. While WT and the pelB fusion are soluble when expressed, the malE fusion was targeted to inclusion bodies and was refolded in vitro to yield a monomeric product with identical secondary structure to WT thioredoxin. The purified recombinant proteins were studied with respect to their thermodynamic stability, aggregation propensity and activity, and compared with wild type thioredoxin, without a signal sequence. The presence of signal sequences leads to thermodynamic destabilization, reduces the activity and increases the aggregation propensity, with malE having much larger effects than pelB. These studies show that besides acting as address labels, signal sequences can modulate protein stability and aggregation in a sequence dependent manner.

  16. Effects of matrix metalloproteinase inhibitor doxycycline and CD147 antagonist peptide-9 on gallbladder carcinoma cell lines.

    Science.gov (United States)

    Wang, Shihang; Liu, Chao; Liu, Xinjiang; He, Yanxin; Shen, Dongfang; Luo, Qiankun; Dong, Yuxi; Dong, Haifeng; Pang, Zhigang

    2017-10-01

    Gallbladder carcinoma is the most common and aggressive malignancy of the biliary tree and highly expresses CD147, which is closely related to disease prognosis in a variety of human cancers. Doxycycline exhibited anti-tumor properties in many cancer cells. CD147 antagonist peptide-9 is a polypeptide and can specifically bind to CD147. The effect of these two drugs on gallbladder cancer cells has not been studied. The aim of this study is to investigate the effect of doxycycline and antagonist peptide-9 on gallbladder carcinoma cells and the possible mechanism of inhibition on cancer cell of doxycycline. To investigate the effects of doxycycline and antagonist peptide-9 on gallbladder carcinoma cells (GBC-SD and SGC-996), cell proliferation, CD147 expression, and early-stage apoptosis rate were measured after treated with doxycycline. Matrix metalloproteinase-2 and matrix metalloproteinase-9 activities were measured after treated with different concentrations of doxycycline, antagonist peptide-9, and their combination. The results demonstrated that doxycycline inhibited cell proliferation, reduced CD147 expression level, and induced an early-stage apoptosis response in GBC-SD and SGC-996 cells. The matrix metalloproteinase-2 and matrix metalloproteinase-9 activities were inhibited by antagonist peptide-9 and doxycycline, and the inhibitory effects were enhanced by combined drugs in gallbladder carcinoma cell lines. Taken together, doxycycline showed inhibitory effects on gallbladder carcinoma cell lines and reduced the expression of CD147, and this may be the mechanism by which doxycycline inhibits cancer cells. This study provides new information and tries to implement the design of adjuvant therapy method for gallbladder carcinoma.

  17. Host defense peptides of thrombin modulate inflammation and coagulation in endotoxin-mediated shock and Pseudomonas aeruginosa sepsis

    DEFF Research Database (Denmark)

    Kalle, Martina; Papareddy, Praveen; Kasetty, Gopinath

    2012-01-01

    Gram-negative sepsis is accompanied by a disproportionate innate immune response and excessive coagulation mainly induced by endotoxins released from bacteria. Due to rising antibiotic resistance and current lack of other effective treatments there is an urgent need for new therapies. We here...... present a new treatment concept for sepsis and endotoxin-mediated shock, based on host defense peptides from the C-terminal part of human thrombin, found to have a broad and inhibitory effect on multiple sepsis pathologies. Thus, the peptides abrogate pro-inflammatory cytokine responses to endotoxin...

  18. Identification and screening of potent antimicrobial peptides in arthropod genomes.

    Science.gov (United States)

    Duwadi, Deepesh; Shrestha, Anishma; Yilma, Binyam; Kozlovski, Itamar; Sa-Eed, Munaya; Dahal, Nikesh; Jukosky, James

    2018-05-01

    Using tBLASTn and BLASTp searches, we queried recently sequenced arthropod genomes and expressed sequence tags (ESTs) using a database of known arthropod cecropins, defensins, and attacins. We identified and synthesized 6 potential AMPs and screened them for antimicrobial activity. Using radial diffusion assays and microtiter antimicrobial assays, we assessed the in vitro antimicrobial effects of these peptides against several human pathogens including Gram-positive and Gram-negative bacteria and fungi. We also conducted hemolysis assays to examine the cytotoxicity of these peptides to mammalian cells. Four of the six peptides identified showed antimicrobial effects in these assays. We also created truncated versions of these four peptides to assay their antimicrobial activity. Two cecropins derived from the monarch butterfly genome (Danaus plexippus), DAN1 and DAN2, showed minimum inhibitory concentrations (MICs) in the range of 2-16 μg/ml when screened against Gram-negative bacteria. HOLO1 and LOUDEF1, two defensin-like peptides derived from red flour beetle (Tribolium castaneum) and human body louse (Pediculus humanus humanus), respectively, exhibited MICs in the range of 13-25 μg/ml against Gram-positive bacteria. Furthermore, HOLO1 showed an MIC less than 5 μg/ml against the fungal species Candida albicans. These peptides exhibited no hemolytic activity at concentrations up to 200 μg/ml. The truncated peptides derived from DAN2 and HOLO1 showed very little antimicrobial activity. Our experiments show that the peptides DAN1, DAN2, HOLO1, and LOUDEF1 showed potent antimicrobial activity in vitro against common human pathogens, did not lyse mammalian red blood cells, and indicates their potential as templates for novel therapeutic agents against microbial infection. Copyright © 2018 Elsevier Inc. All rights reserved.

  19. Effect of incubation time, inoculum size, temperature, pasteurization time, goat milk powder and whey powder on ACE inhibitory activity in fermented milk by L. plantarum LP69.

    Science.gov (United States)

    Shu, Guowei; Yang, Hui; Chen, He; Zhang, Qiuhong; Tian, Yue

    2015-01-01

    Angiotensin I converting enzyme (ACE) plays an important physiological role in regulating hypertension. Lactic acid bacteria are known to produce ACE inhibitory peptides which can lower hypertension during fermentation. The effect of incubation time (0~36 h), inoculum size (3, 4, 5, 6 and 7%, v/v), temperature (25, 30, 35, 40 and 45°C), sterilization time (5, 10, 15, 20 and 25 min), concentration of goat milk powder (8, 10, 12, 14 and 16%, w/v) and whey powder (0.5, 0.6, 0.7, 0.8 and 0.9%, w/v) on ACE inhibitory peptides fermented from goat milk by Lactobacillus plantarum LP69 was investigated using single factor experiment. The optimal incubation time, inoculum size, temperature, pasteurization time, goat milk powder and whey powder in fermented milk by L. plantarum LP69 was 14 h, 3.0%, 35°C, 20 min, 14% and 0.70% for ACE inhibitory activity and 22 h, 3.0%, 40°C, 25 min, 16% and 0.60% for viable cell counts, respectively. The incubation time, inoculum size, temperature, pasteurization time, goat milk powder and whey powder had a significant influence on ACE inhibitory activity in fermented milk by Lactobacillus plantarum LP69, the results are beneficial for further screening of main factors by using fractional factorial designs.

  20. Membrane interaction and secondary structure of de novo designed arginine-and tryptophan peptides with dual function

    KAUST Repository

    Rydberg, Hanna A.

    2012-10-01

    Cell-penetrating peptides and antimicrobial peptides are two classes of positively charged membrane active peptides with several properties in common. The challenge is to combine knowledge about the membrane interaction mechanisms and structural properties of the two classes to design peptides with membrane-specific actions, useful either as transporters of cargo or as antibacterial substances. Membrane active peptides are commonly rich in arginine and tryptophan. We have previously designed a series of arg/trp peptides and investigated how the position and number of tryptophans affect cellular uptake. Here we explore the antimicrobial properties and the interaction with lipid model membranes of these peptides, using minimal inhibitory concentrations assay (MIC), circular dichroism (CD) and linear dichroism (LD). The results show that the arg/trp peptides inhibit the growth of the two gram positive strains Staphylococcus aureus and Staphylococcus pyogenes, with some individual variations depending on the position of the tryptophans. No inhibition of the gram negative strains Proteus mirabilis or Pseudomonas aeruginosa was noticed. CD indicated that when bound to lipid vesicles one of the peptides forms an α-helical like structure, whereas the other five exhibited rather random coiled structures. LD indicated that all six peptides were somehow aligned parallel with the membrane surface. Our results do not reveal any obvious connection between membrane interaction and antimicrobial effect for the studied peptides. By contrast cell-penetrating properties can be coupled to both the secondary structure and the degree of order of the peptides. © 2012 Elsevier Inc.

  1. Practical Tips for Construction of Custom Peptide Libraries and Affinity Selection by Using Commercially Available Phage Display Cloning Systems

    Directory of Open Access Journals (Sweden)

    Keisuke Fukunaga

    2012-01-01

    Full Text Available Phage display technology is undoubtedly a powerful tool for affinity selection of target-specific peptide. Commercially available premade phage libraries allow us to take screening in the easiest way. On the other hand, construction of a custom phage library seems to be inaccessible, because several practical tips are absent in instructions. This paper focuses on what should be born in mind for beginners using commercially available cloning kits (Ph.D. with type 3 vector and T7Select systems for M13 and T7 phage, respectively. In the M13 system, Pro or a basic amino acid (especially, Arg should be avoided at the N-terminus of peptide fused to gp3. In both systems, peptides containing odd number(s of Cys should be designed with caution. Also, DNA sequencing of a constructed library before biopanning is highly recommended for finding unexpected bias.

  2. 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

  3. RR Tel: Getting Under the Flux Limit: An Observation with FUSE

    Science.gov (United States)

    Sonnenborn, George (Technical Monitor); Kenyon, Scott J.

    2004-01-01

    The goal of this program is to acquire a FUSE spectrum of the symbiotic binary RR Tel. With these data, we plan to derive improved constraints on the hot component, the nebula, and perhaps the red giant wind. Based on results from AG Dra, we should also be able to use some line detections to improve atomic parameters for high ionization emission lines. This results would benefit the general FUSE community. As of this writing, the FUSE observation of RR Tel has not been made. Because RR Tel is a very bright UV source, the FUSE team is assessing the likelihood that RR Tel will have an adverse affect on the instrument.

  4. Intracellular protein delivery activity of peptides derived from insulin-like growth factor binding proteins 3 and 5

    International Nuclear Information System (INIS)

    Goda, Natsuko; Tenno, Takeshi; Inomata, Kosuke; Shirakawa, Masahiro; Tanaka, Toshiki; Hiroaki, Hidekazu

    2008-01-01

    Insulin-like growth factor binding proteins (IGFBPs) have various IGF-independent cellular activities, including receptor-independent cellular uptake followed by transcriptional regulation, although mechanisms of cellular entry remain unclear. Herein, we focused on their receptor-independent cellular entry mechanism in terms of protein transduction domain (PTD) activity, which is an emerging technique useful for clinical applications. The peptides of 18 amino acid residues derived from IGFBP-3 and IGFBP-5, which involve heparin-binding regions, mediated cellular delivery of an exogenous protein into NIH3T3 and HeLa cells. Relative protein delivery activities of IGFBP-3/5-derived peptides were approximately 20-150% compared to that of the HIV-Tat peptide, a potent PTD. Heparin inhibited the uptake of the fusion proteins with IGFBP-3 and IGFBP-5, indicating that the delivery pathway is heparin-dependent endocytosis, similar to that of HIV-Tat. The delivery of GST fused to HIV-Tat was competed by either IGFBP-3 or IGFBP-5-derived synthetic peptides. Therefore, the entry pathways of the three PTDs are shared. Our data has shown a new approach for designing protein delivery systems using IGFBP-3/5 derived peptides based on the molecular mechanisms of IGF-independent activities of IGFBPs

  5. HVI Ballistic Limit Characterization of Fused Silica Thermal Panes

    Science.gov (United States)

    Miller, J. E.; Bohl, W. D.; Christiansen, E. L.; Davis, B. A.; Deighton, K. D.

    2015-01-01

    Fused silica window systems are used heavily on crewed reentry vehicles, and they are currently being used on the next generation of US crewed spacecraft, Orion. These systems improve crew situational awareness and comfort, as well as, insulating the reentry critical components of a spacecraft against the intense thermal environments of atmospheric reentry. Additionally, these materials are highly exposed to space environment hazards like solid particle impacts. This paper discusses impact studies up to 10 km/s on a fused silica window system proposed for the Orion spacecraft. A ballistic limit equation that describes the threshold of perforation of a fuse silica pane over a broad range of impact velocities, obliquities and projectile materials is discussed here.

  6. Impact of exogenous hyperglucagonemia on postprandial concentrations of gastric inhibitory polypeptide and glucagon-like peptide-1 in humans

    DEFF Research Database (Denmark)

    Meier, Juris J; Ritter, Peter R; Jacob, Alexandra

    2010-01-01

    Postprandial secretion of glucagon-like peptide 1 (GLP-1) has been found diminished in some patients with type 2 diabetes mellitus (T2DM) and high glucagon concentrations. We examined the effects of exogenous glucagon on the release of incretin hormones.......Postprandial secretion of glucagon-like peptide 1 (GLP-1) has been found diminished in some patients with type 2 diabetes mellitus (T2DM) and high glucagon concentrations. We examined the effects of exogenous glucagon on the release of incretin hormones....

  7. 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.

  8. Liquefier Dynamics in Fused Deposition

    DEFF Research Database (Denmark)

    Bellini, Anna; Guceri, Selcuk; Bertoldi, Maurizio

    2004-01-01

    Layered manufacturing (LM) is an evolution of rapid prototyping (RP) technology whereby a part is built in layers. Fused deposition modeling (FDM) is a particular LM technique in which each section is fabricated through vector style deposition of building blocks, called roads, which...

  9. Artificial 64-Residue HIV-1 Enhancer-Binding Peptide Is a Potent Inhibitor of Viral Replication in HIV-1-Infected Cells.

    Science.gov (United States)

    Oufir, Mouhssin; Bisset, Leslie R; Hoffmann, Stefan R K; Xue, Gongda; Klauser, Stephan; Bergamaschi, Bianca; Gervaix, Alain; Böni, Jürg; Schüpbach, Jörg; Gutte, Bernd

    2011-01-01

    An artificial HIV-1 enhancer-binding peptide was extended by nine consecutive arginine residues at the C-terminus and by the nuclear localization signal of SV40 large T antigen at the N-terminus. The resulting synthetic 64-residue peptide was found to bind to the two enhancers of the HIV-1 long terminal repeat, cross the plasma membrane and the nuclear envelope of human cells, and suppress the HIV-1 enhancer-controlled expression of a green fluorescent protein reporter gene. Moreover, HIV-1 replication is inhibited by this peptide in HIV-1-infected CEM-GFP cells as revealed by HIV-1 p24 ELISA and real-time RT-PCR of HIV-1 RNA. Rapid uptake of this intracellular stable and inhibitory peptide into the cells implies that this peptide may have the potential to attenuate HIV-1 replication in vivo.

  10. 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.

  11. A phage display selected 7-mer peptide inhibitor of the Tannerella forsythia metalloprotease-like enzyme Karilysin can be truncated to Ser-Trp-Phe-Pro.

    Science.gov (United States)

    Skottrup, Peter Durand; Sørensen, Grete; Ksiazek, Miroslaw; Potempa, Jan; Riise, Erik

    2012-01-01

    Tannerella forsythia is a gram-negative bacteria, which is strongly associated with the development of periodontal disease. Karilysin is a newly identified metalloprotease-like enzyme, that is secreted from T. forsythia. Karilysin modulates the host immune response and is therefore considered a likely drug target. In this study peptides were selected towards the catalytic domain from Karilysin (Kly18) by phage display. The peptides were linear with low micromolar binding affinities. The two best binders (peptide14 and peptide15), shared the consensus sequence XWFPXXXGGG. A peptide15 fusion with Maltose Binding protein (MBP) was produced with peptide15 fused to the N-terminus of MBP. The peptide15-MBP was expressed in E. coli and the purified fusion-protein was used to verify Kly18 specific binding. Chemically synthesised peptide15 (SWFPLRSGGG) could inhibit the enzymatic activity of both Kly18 and intact Karilysin (Kly48). Furthermore, peptide15 could slow down the autoprocessing of intact Kly48 to Kly18. The WFP motif was important for inhibition and a truncation study further demonstrated that the N-terminal serine was also essential for Kly18 inhibition. The SWFP peptide had a Ki value in the low micromolar range, which was similar to the intact peptide15. In conclusion SWFP is the first reported inhibitor of Karilysin and can be used as a valuable tool in structure-function studies of Karilysin.

  12. Plasmin digest of κ-casein as a source of antibacterial peptides.

    Science.gov (United States)

    Sedaghati, Marjaneh; Ezzatpanah, Hamid; Boojar, Masoud Mashhadi Akbar; Ebrahimi, Maryam Tajabadi; Aminafshar, Mehdi

    2014-05-01

    This study investigated the antibacterial properties of plasmin, the plasmin hydrolysis of bovine κ-casein and the fractions (named κC1, κC2, κC3, κC4, and κC5) liberated from it using RP-HPLC. The target bacteria were Escherichia coli, Staphylococcus aureus (pathogenic), Lactobacillus casei and Lactobacillus acidophilus (probiotic). Three peptides (kC1, kC3, and kC4) were found to have antibacterial activity, with κC3 peptide being the most active. The plasmin digest of bovine κ-casein proved to be stronger than any of its fractions in terms of antibacterial potential. Measurement of the minimum inhibitory concentration (MIC) showed that Gram-positive bacteria are generally more sensitive to antibacterial activity than Gram-negative bacteria. The MIC of nisin, as a bacteriocin peptide, was also measured. The three antibacterial peptides were identified using LC-Mass. The molecular mass of kC1, kC3, and kC4 corresponded to the f(17-21), f(22-24), and f(1-3) of bovine κ-casein, respectively. It was also found that the positive charge and hydrophobicity of a peptide are not key factors in antibacterial activity. On the whole, the present study demonstrated that the plasmin digest of κ-casein has a high antibacterial potential and can be considered as a natural antibacterial agent in the food chain.

  13. Technological aspects of using protective fuses in low-voltage mine networks

    Energy Technology Data Exchange (ETDEWEB)

    Kowalski, Z; Pudelko, H

    1986-04-01

    Protection systems are evaluated for mining equipment used in underground coal mining in Poland. Operation of contactor switches is analyzed. Systems for protection of vacuum contactor switches from overload are comparatively evaluated. Types of current reducers are reviewed. Design of the aM protection fuse which is activated only when overload current exceeds the limiting level is analyzed. Protection fuses with the aM characteristic meeting IEC and VDE requirements for fuses used in SV5, SV7 and SV8 vacuum contactors for power networks of up to 1000 V are evaluated. Characteristics of the vacuum contactors manufactured in Poland are given in 6 diagrams and 2 tables. Reliability of the vacuum contactors with aM protection fuses is analyzed. 8 references.

  14. Secapin, a bee venom peptide, exhibits anti-fibrinolytic, anti-elastolytic, and anti-microbial activities.

    Science.gov (United States)

    Lee, Kwang Sik; Kim, Bo Yeon; Yoon, Hyung Joo; Choi, Yong Soo; Jin, Byung Rae

    2016-10-01

    Bee venom contains a variety of peptide constituents that have various biological, toxicological, and pharmacological actions. However, the biological actions of secapin, a venom peptide in bee venom, remain largely unknown. Here, we provide the evidence that Asiatic honeybee (Apis cerana) secapin (AcSecapin-1) exhibits anti-fibrinolytic, anti-elastolytic, and anti-microbial activities. The recombinant mature AcSecapin-1 peptide was expressed in baculovirus-infected insect cells. AcSecapin-1 functions as a serine protease inhibitor-like peptide that has inhibitory effects against plasmin, elastases, microbial serine proteases, trypsin, and chymotrypsin. Consistent with these functions, AcSecapin-1 inhibited the plasmin-mediated degradation of fibrin to fibrin degradation products, thus indicating the role of AcSecapin-1 as an anti-fibrinolytic agent. AcSecapin-1 also inhibited both human neutrophil and porcine pancreatic elastases. Furthermore, AcSecapin-1 bound to bacterial and fungal surfaces and exhibited anti-microbial activity against fungi and gram-positive and gram-negative bacteria. Taken together, our data demonstrated that the bee venom peptide secapin has multifunctional roles as an anti-fibrinolytic agent during fibrinolysis and an anti-microbial agent in the innate immune response. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Small surfactant-like peptides can drive soluble proteins into active aggregates

    Directory of Open Access Journals (Sweden)

    Zhou Bihong

    2012-01-01

    Full Text Available Abstract Background Inactive protein inclusion bodies occur commonly in Escherichia coli (E. coli cells expressing heterologous proteins. Previously several independent groups have found that active protein aggregates or pseudo inclusion bodies can be induced by a fusion partner such as a cellulose binding domain from Clostridium cellulovorans (CBDclos when expressed in E. coli. More recently we further showed that a short amphipathic helical octadecapeptide 18A (EWLKAFYEKVLEKLKELF and a short beta structure peptide ELK16 (LELELKLKLELELKLK have a similar property. Results In this work, we explored a third type of peptides, surfactant-like peptides, for performing such a "pulling-down" function. One or more of three such peptides (L6KD, L6K2, DKL6 were fused to the carboxyl termini of model proteins including Aspergillus fumigatus amadoriase II (AMA, all three peptides were used, Bacillus subtilis lipase A (LipA, only L6KD was used, hereinafter the same, Bacillus pumilus xylosidase (XynB, and green fluorescent protein (GFP, and expressed in E. coli. All fusions were found to predominantly accumulate in the insoluble fractions, with specific activities ranging from 25% to 92% of the native counterparts. Transmission electron microscopic (TEM and confocal fluorescence microscopic analyses confirmed the formation of protein aggregates in the cell. Furthermore, binding assays with amyloid-specific dyes (thioflavin T and Cong red to the AMA-L6KD aggregate and the TEM analysis of the aggregate following digestion with protease K suggested that the AMA-L6KD aggregate may contain structures reminiscent of amyloids, including a fibril-like structure core. Conclusions This study shows that the surfactant-like peptides L6KD and it derivatives can act as a pull-down handler for converting soluble proteins into active aggregates, much like 18A and ELK16. These peptide-mediated protein aggregations might have important implications for protein aggregation in

  16. Sorting of a HaloTag protein that has only a signal peptide sequence into exocrine secretory granules without protein aggregation.

    Science.gov (United States)

    Fujita-Yoshigaki, Junko; Matsuki-Fukushima, Miwako; Yokoyama, Megumi; Katsumata-Kato, Osamu

    2013-11-15

    The mechanism involved in the sorting and accumulation of secretory cargo proteins, such as amylase, into secretory granules of exocrine cells remains to be solved. To clarify that sorting mechanism, we expressed a reporter protein HaloTag fused with partial sequences of salivary amylase protein in primary cultured parotid acinar cells. We found that a HaloTag protein fused with only the signal peptide sequence (Met(1)-Ala(25)) of amylase, termed SS25H, colocalized well with endogenous amylase, which was confirmed by immunofluorescence microscopy. Percoll-density gradient centrifugation of secretory granule fractions shows that the distributions of amylase and SS25H were similar. These results suggest that SS25H is transported to secretory granules and is not discriminated from endogenous amylase by the machinery that functions to remove proteins other than granule cargo from immature granules. Another reporter protein, DsRed2, that has the same signal peptide sequence also colocalized with amylase, suggesting that the sorting to secretory granules is not dependent on a characteristic of the HaloTag protein. Whereas Blue Native PAGE demonstrates that endogenous amylase forms a high-molecular-weight complex, SS25H does not participate in the complex and does not form self-aggregates. Nevertheless, SS25H was released from cells by the addition of a β-adrenergic agonist, isoproterenol, which also induces amylase secretion. These results indicate that addition of the signal peptide sequence, which is necessary for the translocation in the endoplasmic reticulum, is sufficient for the transportation and storage of cargo proteins in secretory granules of exocrine cells.

  17. An evolutionary scenario for gonadotrophin-inhibitory hormone in chordates.

    Science.gov (United States)

    Osugi, T; Ubuka, T; Tsutsui, K

    2015-06-01

    In 2000, we discovered a novel hypothalamic neuropeptide that actively inhibits gonadotrophin release in quail and termed it gonadotrophin-inhibitory hormone (GnIH). GnIH peptides have subsequently been identified in most representative species of gnathostomes. They all share a C-terminal LPXRFamide (X = L or Q) motif. GnIH can inhibit gonadotrophin synthesis and release by decreasing the activity of GnRH neuroes, as well as by directly inhibiting pituitary gonadotrophin secretion in birds and mammals. To investigate the evolutionary origin of GnIH and its ancestral function, we identified a GnIH precursor gene encoding GnIHs from the brain of sea lamprey, the most ancient lineage of vertebrates. Lamprey GnIHs possess a C-terminal PQRFamide motif. In vivo administration of one of lamprey GnIHs stimulated the expression of lamprey GnRH in the hypothalamus and gonadotophin β mRNA in the pituitary. Thus, GnIH may have emerged in agnathans as a stimulatory neuropeptide that subsequently diverged to an inhibitory neuropeptide during the course of evolution from basal vertebrates to later-evolved vertebrates, such as birds and mammals. From a structural point of view, pain modulatory neuropeptides, such as neuropeptide FF (NPFF) and neuropeptide AF, share a C-terminal PQRFamide motif. Because agnathans possess both GnIH and NPFF genes, the origin of GnIH and NPFF genes may date back before the emergence of agnathans. More recently, we identified a novel gene encoding RFamide peptides in the amphioxus. Molecular phylogenetic analysis and synteny analysis indicated that this gene is closely related to the genes of GnIH and NPFF of vertebrates. The results suggest that the identified protochordate gene is similar to the common ancestor of GnIH and NPFF genes, indicating that the origin of GnIH and NPFF may date back to the time of the emergence of early chordates. The GnIH and NPFF genes may have diverged by whole-genome duplication during the course of vertebrate

  18. Quantification of residual stress from photonic signatures of fused silica

    International Nuclear Information System (INIS)

    Cramer, K. Elliott; Yost, William T.; Hayward, Maurice

    2014-01-01

    A commercially available grey-field polariscope (GFP) instrument for photoelastic examination is used to assess impact damage inflicted upon the outer-most pane of Space Shuttle windows made from fused silica. A method and apparatus for calibration of the stress-optic coefficient using four-point bending is discussed. The results are validated on known material (acrylic) and are found to agree with literature values to within 6%. The calibration procedure is then applied to fused-silica specimens and the stress-optic coefficient is determined to be 2.43 ± 0.54 × 10 −12 Pa −1 . Fused silica specimens containing impacts artificially made at NASA’s Hypervelocity Impact Technology Facility (HIT-F), to simulate damage typical during space flight, are examined. The damage sites are cored from fused silica window carcasses and examined with the GFP. The calibrated GFP measurements of residual stress patterns surrounding the damage sites are presented

  19. A Macrocyclic Peptide that Serves as a Cocrystallization Ligand and Inhibits the Function of a MATE Family Transporter

    Directory of Open Access Journals (Sweden)

    Hiroaki Suga

    2013-08-01

    Full Text Available The random non-standard peptide integrated discovery (RaPID system has proven to be a powerful approach to discover de novo natural product-like macrocyclic peptides that inhibit protein functions. We have recently reported three macrocyclic peptides that bind to Pyrococcus furiosus multidrug and toxic compound extrusion (PfMATE transporter and inhibit the transport function. Moreover, these macrocyclic peptides were successfully employed as cocrystallization ligands of selenomethionine-labeled PfMATE. In this report, we disclose the details of the RaPID selection strategy that led to the identification of these three macrocyclic peptides as well as a fourth macrocyclic peptide, MaD8, which is exclusively discussed in this article. MaD8 was found to bind within the cleft of PfMATE’s extracellular side and blocked the path of organic small molecules being extruded. The results of an ethidium bromide efflux assay confirmed the efflux inhibitory activity of MaD8, whose behavior was similar to that of previously reported MaD5.

  20. Full spectrum endoscopy (FUSE) versus standard forward-viewing endoscope (SFV) in a high-risk population

    DEFF Research Database (Denmark)

    Roepstorff, Søren; Hadi, Sabah Anwar; Rasmussen, Morten

    2017-01-01

    OBJECTIVES: To investigate the diagnostic performance of Full Spectrum Endoscopy (FUSE) compared to a conventional standard forward-viewing endoscope (SFV). The primary outcome was adenoma detection rate (ADR) and mean adenoma detection. Secondary outcome was feasibility of FUSE opposed to SFV...... intubation time, fentanyl and midazolam sedation, CRC detection, ADR, diverticulosis, bowel preparation, patient discomfort and endoscopist difficulty rating. Participants underwent FUSE colonoscopy on days when the FUSE system was available, while the remaining participants had SFV. All colonoscopies were.......1 ± 6.2 min in the FUSE and SFV groups (p = .040). ADR was 67.0% and 59.6% (p = .097), while the mean adenoma detection was 1.79 and 1.38 (p = .022) in the FUSE and SFV groups. Endoscopists reported increased difficulty rating with FUSE compared to SFV (p > .001). CONCLUSION: FUSE colonoscopy provides...

  1. Antimicrobial activity and mechanism of PDC213, an endogenous peptide from human milk

    International Nuclear Information System (INIS)

    Sun, Yazhou; Zhou, Yahui; Liu, Xiao; Zhang, Fan; Yan, Linping; Chen, Ling; Wang, Xing; Ruan, Hongjie; Ji, Chenbo; Cui, Xianwei; Wang, Jiaqin

    2017-01-01

    Human milk has always been considered an ideal source of elemental nutrients to both preterm and full term infants in order to optimally develop the infant's tissues and organs. Recently, hundreds of endogenous milk peptides were identified in human milk. These peptides exhibited angiotensin-converting enzyme inhibition, immunomodulation, or antimicrobial activity. Here, we report the antimicrobial activity and mechanism of a novel type of human antimicrobial peptide (AMP), termed PDC213 (peptide derived from β-Casein 213-226 aa). PDC213 is an endogenous peptide and is present at higher levels in preterm milk than in full term milk. The inhibitory concentration curve and disk diffusion tests showed that PDC213 had obvious antimicrobial against S. aureus and Y. enterocolitica, the common nosocomial pathogens in neonatal intensive care units (NICUs). Fluorescent dye methods, electron microscopy experiments and DNA-binding activity assays further indicated that PDC213 can permeabilize bacterial membranes and cell walls rather than bind intracellular DNA to kill bacteria. Together, our results suggest that PDC213 is a novel type of AMP that warrants further investigation. - Highlights: • PDC213 is an endogenous peptide presenting higher levels in preterm milk. • PDC213 showed obvious antimicrobial against S. aereus and Y. enterocolitica. • PDC213 can permeabilize bacterial membranes and cell walls to kill bacterias. • PDC213 is a novel type of antimicrobial peptides worthy further investigation.

  2. Identities of P2 and P3 Residues of H-2Kb-Bound Peptides Determine Mouse Ly49C Recognition.

    Directory of Open Access Journals (Sweden)

    Elsa A Marquez

    Full Text Available Ly49 receptors can be peptide selective in their recognition of MHC-I-peptide complexes, affording them a level of discrimination beyond detecting the presence or absence of specific MHC-I allele products. Despite this ability, little is understood regarding the properties that enable some peptides, when bound to MHC-I molecules, to support Ly49 recognition, but not others. Using RMA-S target cells expressing MHC-I molecules loaded with individual peptides and effector cells expressing the ectodomain of the inhibitory Ly49C receptor, we found that two adjacent amino acid residues, P2 and P3, both buried in the peptide binding groove of H-2Kb, determine mouse Ly49C specificity. If both are aliphatic residues, this is supportive. Whereas, small amino acids at P2 and aromatic amino acids at the P3 auxiliary anchor residue are detrimental to Ly49C recognition. These results resemble those with a rat Ly49 where the identity of a peptide anchor residue determines recognition, suggesting that dependence on specific peptide residues buried in the MHC-I peptide-binding groove may be fundamental to Ly49 peptide selectivity and recognition.

  3. Hybrid Z-Θ Pinches with fused capacitor banks

    International Nuclear Information System (INIS)

    Grandey, R.; Gersten, M.; Loter, N.; Rauch, J.; Rostoker, N.; Thompson, W.; Ware, K.

    1987-01-01

    The Hybrid Z-Θ Pinch circuit equations in the thin shell model were reexamined to see what advantages can be obtained by using a fused, high-energy (>--1MJ) bank driver. The DNA ACE facility at MLI utilizes a 36 μF capacitor band which can be charged to 120 kV to provide 250 kJ of stored energy. This configuration appears to be very appropriate to test the performance of a hybrid-stabilized fused-bank driven pinch. The circuit analyses suggest that the energy transfer efficiency from the bank to a pinched plasma can be increased from less than 1%, for a nonfused bank, to about 10% for a fused configuration. In the applicable region of parameter space, the Hybrid Pinch does not increase the efficiency of energy transfer into the plasma over that obtainable from a Z-pinch. The additional stability may allow larger initial radii to be used with concomitant improved coupling into radiation above 1 keV

  4. Artificial 64-Residue HIV-1 Enhancer-Binding Peptide Is a Potent Inhibitor of Viral Replication in HIV-1-Infected Cells

    Directory of Open Access Journals (Sweden)

    Mouhssin Oufir

    2011-01-01

    Full Text Available An artificial HIV-1 enhancer-binding peptide was extended by nine consecutive arginine residues at the C-terminus and by the nuclear localization signal of SV40 large T antigen at the N-terminus. The resulting synthetic 64-residue peptide was found to bind to the two enhancers of the HIV-1 long terminal repeat, cross the plasma membrane and the nuclear envelope of human cells, and suppress the HIV-1 enhancer-controlled expression of a green fluorescent protein reporter gene. Moreover, HIV-1 replication is inhibited by this peptide in HIV-1-infected CEM-GFP cells as revealed by HIV-1 p24 ELISA and real-time RT-PCR of HIV-1 RNA. Rapid uptake of this intracellular stable and inhibitory peptide into the cells implies that this peptide may have the potential to attenuate HIV-1 replication in vivo.

  5. Atomic force microscopy of bacteria reveals the mechanobiology of pore forming peptide action.

    Science.gov (United States)

    Mularski, Anna; Wilksch, Jonathan J; Hanssen, Eric; Strugnell, Richard A; Separovic, Frances

    2016-06-01

    Time-resolved AFM images revealed that the antimicrobial peptide (AMP) caerin 1.1 caused localised defects in the cell walls of lysed Klebsiella pneumoniae cells, corroborating a pore-forming mechanism of action. The defects continued to grow during the AFM experiment, in corroboration with large holes that were visualised by scanning electron microscopy. Defects in cytoplasmic membranes were visualised by cryo-EM using the same peptide concentration as in the AFM experiments. At three times the minimum inhibitory concentration of caerin, 'pores' were apparent in the outer membrane. The capsule of K. pneumoniae AJ218 was unchanged by exposure to caerin, indicating that the ionic interaction of the positively charged peptide with the negatively charged capsular polysaccharide is not a critical component of AMP interaction with K. pneumoniae AJ218 cells. Further, the presence of a capsule confers no advantage to wild-type over capsule-deficient cells when exposed to the AMP caerin. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Exploding metallic fuse physics experiments

    International Nuclear Information System (INIS)

    Goforth, J.H.; Hackett, K.E.; Lindemuth, I.R.; Lopez, E.A.; McCullough, W.F.; Dona, H.; Reinovsky, R.E.

    1986-01-01

    The ultimate practicality of inductive pulse compression systems as drivers for energetic plasma implosions hinges on the development of a suitable opening switch capable of interrupting tons of megamp currents in time scales of a few hundred nanoseconds while withstanding L(dI/dt) voltages of a megavolt or more. 1. Exploding metallic foils (fuses) are a candidate for switching elements in the inductive store pulsed power systems used in the Los Alamos and Air Force Weapons Laboratory foil implosion X-ray source generation programs. To verify or modify new theoretical and computational predictions about the electrical and hydrodynamic behavior of exploding metallic foils used as fuses. The authors have initiated a new series of small scale capacitor bank driven fuse experiments. The experiments represent an extension of previous experiments, but in the new series a foil geometry more amenable to theoretical and computational analysis is used. The metallic foil (aluminum or copper) is laminated between two thin layers of insulating material (mylar or kaptan). Adjacent to one layer of insulation is a much heavier backing insulator (polyethylene) whereas air is adjacent to the other layer. Because of the differing masses on the two sides of the foil, the foil expansion and hydrodynamic motion is essentially one-sided and the layer of insulation on the expanding side becomes a readily-characterizable ''flyer'' which provides a controlled amount of hydrodynamic tamping. In addition to the usual voltage, current, and dI/dt electrical measurements, time-resolved spectrometer measurements are used to determine the temperature of the expanding metallic foil. Post-shot examination of the flyer and the insulation impacted by the flyer gives insight into the experimental behavior

  7. Morphological evaluation of maxillary second molars with fused roots: a micro-CT study.

    Science.gov (United States)

    Ordinola-Zapata, R; Martins, J N R; Bramante, C M; Villas-Boas, M H; Duarte, M H; Versiani, M A

    2017-12-01

    To evaluate the internal and external morphologies of fused-rooted maxillary second molars by means of micro-computed tomography (micro-CT) analysis. A total of 100 fused-rooted maxillary second molars from a Brazilian subpopulation were divided into six groups according to the root morphology. The samples were scanned at a resolution of 19.6 μm and evaluated with regard to the external morphology of the roots, the root canal configuration, the percentage frequency of C-shaped canals and isthmuses, as well as the morphology of the root canal system at 1, 2 and 3 mm from the anatomical apex of the fused roots. The most prevalent root canal fusions were type 1, mesiobuccal root fused with distobuccal root (32%), followed by type 3, DB root fused with P root (27%), and type 4, MB root fused with DB root, and P root fused with MB or DB roots (21%). The prevalence of C-shaped root canal systems were 22%. Depending on the type of root fusion, the percentage frequency of isthmuses in the apical level varied from 9.3% to 42.8%, whilst the presence of apical deltas ranged from 18.5% to 57.1% of teeth. The root canal system of maxillary second molars with fused roots may have a high incidence of merging canals, isthmuses, apical deltas and C-shaped configurations. © 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  8. Electro-Deformation of Fused Cells in a Microfluidic Array Device

    Directory of Open Access Journals (Sweden)

    Yan Liu

    2016-11-01

    Full Text Available We present a new method of analyzing the deformability of fused cells in a microfluidic array device. Electrical stresses—generated by applying voltages (4–20 V across discrete co-planar microelectrodes along the side walls of a microfluidic channel—have been used to electro-deform fused and unfused stem cells. Under an electro-deformation force induced by applying an alternating current (AC signal, we observed significant electro-deformation phenomena. The experimental results show that the fused stem cells were stiffer than the unfused stem cells at a relatively low voltage (<16 V. However, at a relatively high voltage, the fused stem cells were more easily deformed than were the unfused stem cells. In addition, the electro-deformation process is modeled based on the Maxwell stress tensor and structural mechanics of cells. The theoretical results show that a positive correlation is found between the deformation of the cell and the applied voltage, which is consistent with the experimental results. Combined with a numerical analysis and experimental study, the results showed that the significant difference of the deformation ratio of the fused and unfused cells is not due to their size difference. This demonstrates that some other properties of cell membranes (such as the membrane structure were also changed in the electrofusion process, in addition to the size modification of that process.

  9. Refractive index sensors based on the fused tapered special multi-mode fiber

    Science.gov (United States)

    Fu, Xing-hu; Xiu, Yan-li; Liu, Qin; Xie, Hai-yang; Yang, Chuan-qing; Zhang, Shun-yang; Fu, Guang-wei; Bi, Wei-hong

    2016-01-01

    In this paper, a novel refractive index (RI) sensor is proposed based on the fused tapered special multi-mode fiber (SMMF). Firstly, a section of SMMF is spliced between two single-mode fibers (SMFs). Then, the SMMF is processed by a fused tapering machine, and a tapered fiber structure is fabricated. Finally, a fused tapered SMMF sensor is obtained for measuring external RI. The RI sensing mechanism of tapered SMMF sensor is analyzed in detail. For different fused tapering lengths, the experimental results show that the RI sensitivity can be up to 444.517 81 nm/RIU in the RI range of 1.334 9—1.347 0. The RI sensitivity is increased with the increase of fused tapering length. Moreover, it has many advantages, including high sensitivity, compact structure, fast response and wide application range. So it can be used to measure the solution concentration in the fields of biochemistry, health care and food processing.

  10. 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.

  11. Peptide Inhibitor of Complement C1 (PIC1 Rapidly Inhibits Complement Activation after Intravascular Injection in Rats.

    Directory of Open Access Journals (Sweden)

    Julia A Sharp

    Full Text Available The complement system has been increasingly recognized to play a pivotal role in a variety of inflammatory and autoimmune diseases. Consequently, therapeutic modulators of the classical, lectin and alternative pathways of the complement system are currently in pre-clinical and clinical development. Our laboratory has identified a peptide that specifically inhibits the classical and lectin pathways of complement and is referred to as Peptide Inhibitor of Complement C1 (PIC1. In this study, we determined that the lead PIC1 variant demonstrates a salt-dependent binding to C1q, the initiator molecule of the classical pathway. Additionally, this peptide bound to the lectin pathway initiator molecule MBL as well as the ficolins H, M and L, suggesting a common mechanism of PIC1 inhibitory activity occurs via binding to the collagen-like tails of these collectin molecules. We further analyzed the effect of arginine and glutamic acid residue substitution on the complement inhibitory activity of our lead derivative in a hemolytic assay and found that the original sequence demonstrated superior inhibitory activity. To improve upon the solubility of the lead derivative, a pegylated, water soluble variant was developed, structurally characterized and demonstrated to inhibit complement activation in mouse plasma, as well as rat, non-human primate and human serum in vitro. After intravenous injection in rats, the pegylated derivative inhibited complement activation in the blood by 90% after 30 seconds, demonstrating extremely rapid function. Additionally, no adverse toxicological effects were observed in limited testing. Together these results show that PIC1 rapidly inhibits classical complement activation in vitro and in vivo and is functional for a variety of animal species, suggesting its utility in animal models of classical complement-mediated diseases.

  12. 2D-QSAR in hydroxamic acid derivatives as peptide deformylase inhibitors and antibacterial agents.

    Science.gov (United States)

    Gupta, Manish K; Mishra, Pradeep; Prathipati, Philip; Saxena, Anil K

    2002-12-01

    Peptide deformylase catalyzes the removal of N-formyl group from the N-formylmethionine of ribosome synthesized polypeptide in eubacteria. Quantitative structure-activity relationship (QSAR) studies have been carried out in a series of beta-sulfonyl and beta-sulfinyl hydroxamic acid derivatives for their PDF enzyme inhibitory and antibacterial activities against Escherichia coli DC2 and Moraxella catarrhalis RA21 which demonstrate that the PDF inhibitory activity in cell free and whole cell system increases with increase in molar refractivity and hydrophobicity. The comparison of the QSARs between the cell free and whole cell system indicate that the active binding sites in PDF isolated from E. coli and in M. catarrhalis RA21 are similar and the whole cell antibacterial activity is mainly due to the inhibition of PDF. Apart from this the QSARs on some matrixmetelloproteins (COL-1, COL-3, MAT and HME) and natural endopeptidase (NEP) indicate the possibilities of introducing selectivity in these hydroxamic acid derivatives for their PDF inhibitory activity.

  13. Antioxidant activity of a novel synthetic hexa-peptide derived from an enzymatic hydrolysate of duck skin by-products.

    Science.gov (United States)

    Lee, Seung-Jae; Cheong, Sun Hee; Kim, Yon-Suk; Hwang, Jin-Woo; Kwon, Hyuck-Ju; Kang, Seo-Hee; Moon, Sang-Ho; Jeon, Byong-Tae; Park, Pyo-Jam

    2013-12-01

    A peptide was synthesized on the basis of our previous study from solid phase peptide synthesis using ASP48S (Peptron Inc.) and identified by the reverse phase high-performance liquid chromatography (HPLC) using a Vydac Everest C18 column. The molecular mass of the peptide found to be 693.90 Da, and the amino acid sequences of the peptide was Trp-Tyr-Pro-Ala-Ala-Pro. The purpose of this study was to evaluate antioxidant effects of the peptide by electron spin resonance (ESR) spectrometer, and on t-BHP-induced liver cells damage in Chang cells. The antioxidative activity of the peptide was evaluated by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl, alkyl and superoxide radical scavenging activity using an ESR spectrometer. The half maximal inhibitory concentration (IC50) value of the peptide for hydroxyl, DPPH, alkyl, and superoxide radical scavenging activity were 45.2, 18.5, 31.5, and 33.4 μM, respectively. In addition, the peptide inhibited productions of cell death against t-BHP-induced liver cell damage in Chang cells. It was presumed to be peptide involved in regulating the apoptosis-related gene expression in the cell environment. The present results indicate that the peptide substantially contributes to antioxidative properties in liver cells. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. A phage display selected 7-mer peptide inhibitor of the Tannerella forsythia metalloprotease-like enzyme Karilysin can be truncated to Ser-Trp-Phe-Pro.

    Directory of Open Access Journals (Sweden)

    Peter Durand Skottrup

    Full Text Available Tannerella forsythia is a gram-negative bacteria, which is strongly associated with the development of periodontal disease. Karilysin is a newly identified metalloprotease-like enzyme, that is secreted from T. forsythia. Karilysin modulates the host immune response and is therefore considered a likely drug target. In this study peptides were selected towards the catalytic domain from Karilysin (Kly18 by phage display. The peptides were linear with low micromolar binding affinities. The two best binders (peptide14 and peptide15, shared the consensus sequence XWFPXXXGGG. A peptide15 fusion with Maltose Binding protein (MBP was produced with peptide15 fused to the N-terminus of MBP. The peptide15-MBP was expressed in E. coli and the purified fusion-protein was used to verify Kly18 specific binding. Chemically synthesised peptide15 (SWFPLRSGGG could inhibit the enzymatic activity of both Kly18 and intact Karilysin (Kly48. Furthermore, peptide15 could slow down the autoprocessing of intact Kly48 to Kly18. The WFP motif was important for inhibition and a truncation study further demonstrated that the N-terminal serine was also essential for Kly18 inhibition. The SWFP peptide had a Ki value in the low micromolar range, which was similar to the intact peptide15. In conclusion SWFP is the first reported inhibitor of Karilysin and can be used as a valuable tool in structure-function studies of Karilysin.

  15. Antimicrobial Activity and Stability of Short and Long Based Arachnid Synthetic Peptides in the Presence of Commercial Antibiotics.

    Science.gov (United States)

    Arenas, Ivan; Villegas, Elba; Walls, Oliver; Barrios, Humberto; Rodríguez, Ramon; Corzo, Gerardo

    2016-02-17

    Four antimicrobial peptides (AMPs) named Pin2[G], Pin2[14], P18K and FA1 were chemically synthesized and purified. The four peptides were evaluated in the presence of eight commercial antibiotics against four microorganisms of medical importance: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae. The commercial antibiotics used were amoxicillin, azithromycin, ceftriaxone, gentamicin, levofloxacin, sulfamethoxazole, trimethoprim and vancomycin. The best AMP against P. aeruginosa was the peptide FA1, and the best AMP against S. aureus was Pin2[G]. Both FA1 and Pin2[G] were efficient against E. coli, but they were not effective against K. pneumoniae. As K. pneumoniae was resistant to most of the commercial antibiotics, combinations of the AMPs FA1 and Pin2[G] were prepared with these antibiotics. According to the fractional inhibitory concentration (FIC) index, the best antimicrobial combinations were obtained with concomitant applications of mixtures of FA1 with levofloxacin and sulfamethoxazole. However, combinations of FA1 or Pin2[G] with other antibiotics showed that total inhibitory effect of the combinations were greater than the sum of the individual effects of either the antimicrobial peptide or the antibiotic. We also evaluated the stability of the AMPs. The AMP Pin2[G] manifested the best performance in saline buffer, in supernatants of bacterial growth and in human blood plasma. Nevertheless, all AMPs were cleaved using endoproteolytic enzymes. These data show advantages and disadvantages of AMPs for potential clinical treatments of bacterial infections, using them in conjunction with commercial antibiotics.

  16. Antimicrobial Activity and Stability of Short and Long Based Arachnid Synthetic Peptides in the Presence of Commercial Antibiotics

    Directory of Open Access Journals (Sweden)

    Ivan Arenas

    2016-02-01

    Full Text Available Four antimicrobial peptides (AMPs named Pin2[G], Pin2[14], P18K and FA1 were chemically synthesized and purified. The four peptides were evaluated in the presence of eight commercial antibiotics against four microorganisms of medical importance: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae. The commercial antibiotics used were amoxicillin, azithromycin, ceftriaxone, gentamicin, levofloxacin, sulfamethoxazole, trimethoprim and vancomycin. The best AMP against P. aeruginosa was the peptide FA1, and the best AMP against S. aureus was Pin2[G]. Both FA1 and Pin2[G] were efficient against E. coli, but they were not effective against K. pneumoniae. As K. pneumoniae was resistant to most of the commercial antibiotics, combinations of the AMPs FA1 and Pin2[G] were prepared with these antibiotics. According to the fractional inhibitory concentration (FIC index, the best antimicrobial combinations were obtained with concomitant applications of mixtures of FA1 with levofloxacin and sulfamethoxazole. However, combinations of FA1 or Pin2[G] with other antibiotics showed that total inhibitory effect of the combinations were greater than the sum of the individual effects of either the antimicrobial peptide or the antibiotic. We also evaluated the stability of the AMPs. The AMP Pin2[G] manifested the best performance in saline buffer, in supernatants of bacterial growth and in human blood plasma. Nevertheless, all AMPs were cleaved using endoproteolytic enzymes. These data show advantages and disadvantages of AMPs for potential clinical treatments of bacterial infections, using them in conjunction with commercial antibiotics.

  17. Investigation of the antimicrobial activities of Snakin-Z, a new cationic peptide derived from Zizyphus jujuba fruits.

    Science.gov (United States)

    Daneshmand, Fatemeh; Zare-Zardini, Hadi; Ebrahimi, Leila

    2013-01-01

    Snakin-Z is a novel antimicrobial peptide (AMP) that is identified from the fruit of Zizyphus jujuba. This peptide is composed of 31 amino acids which is determined with the sequence of CARLNCVPKGTSGNTETCPCYASLHSCRKYG and molecular weight of 3318.82 Da. Snakin-Z is not identical to any AMP in the peptide database. According to this study, Snakin-Z potentially has antimicrobial property against bacteria and fungi. Minimal inhibitory concentration (MIC) value of this peptide is suitable for antimicrobial activity. We assessed that Snakin-Z could affect Phomopsis azadirachtae with the MIC value of 7.65 μg/mL and vice versa Staphylococcus aureus with the MIC value of 28.8 μg/mL. Interestingly, human red blood cells also showed good tolerance to the Snakin-Z. On the basis of this study, Snakin-Z can be an appropriate candidate for therapeutic applications in the future due to its antimicrobial property.

  18. 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.

  19. A general strategy to endow natural fusion-protein-derived peptides with potent antiviral activity.

    Directory of Open Access Journals (Sweden)

    Antonello Pessi

    Full Text Available Fusion between the viral and target cell membranes is an obligatory step for the infectivity of all enveloped virus, and blocking this process is a clinically validated therapeutic strategy.Viral fusion is driven by specialized proteins which, although specific to each virus, act through a common mechanism, the formation of a complex between two heptad repeat (HR regions. The HR regions are initially separated in an intermediate termed "prehairpin", which bridges the viral and cell membranes, and then fold onto each other to form a 6-helical bundle (6HB, driving the two membranes to fuse. HR-derived peptides can inhibit viral infectivity by binding to the prehairpin intermediate and preventing its transition to the 6HB.The antiviral activity of HR-derived peptides differs considerably among enveloped viruses. For weak inhibitors, potency can be increased by peptide engineering strategies, but sequence-specific optimization is time-consuming. In seeking ways to increase potency without changing the native sequence, we previously reported that attachment to the HR peptide of a cholesterol group ("cholesterol-tagging" dramatically increases its antiviral potency, and simultaneously increases its half-life in vivo. We show here that antiviral potency may be increased by combining cholesterol-tagging with dimerization of the HR-derived sequence, using as examples human parainfluenza virus, Nipah virus, and HIV-1. Together, cholesterol-tagging and dimerization may represent strategies to boost HR peptide potency to levels that in some cases may be compatible with in vivo use, possibly contributing to emergency responses to outbreaks of existing or novel viruses.

  20. Antimicrobial Peptide Trichokonin VI-Induced Alterations in the Morphological and Nanomechanical Properties of Bacillus subtilis

    OpenAIRE

    Su, Hai-Nan; Chen, Zhi-Hua; Song, Xiao-Yan; Chen, Xiu-Lan; Shi, Mei; Zhou, Bai-Cheng; Zhao, Xian; Zhang, Yu-Zhong

    2012-01-01

    Antimicrobial peptides are promising alternative antimicrobial agents compared to conventional antibiotics. Understanding the mode of action is important for their further application. We examined the interaction between trichokonin VI, a peptaibol isolated from Trichoderma pseudokoningii, and Bacillus subtilis, a representative Gram-positive bacterium. Trichokonin VI was effective against B. subtilis with a minimal inhibitory concentration of 25 µM. Trichokonin VI exhibited a concentration- ...

  1. Gastrin-Releasing Peptide and Glucose Metabolism Following Pancreatitis.

    Science.gov (United States)

    Pendharkar, Sayali A; Drury, Marie; Walia, Monika; Korc, Murray; Petrov, Maxim S

    2017-08-01

    Gastrin-releasing peptide (GRP) is a pluripotent peptide that has been implicated in both gastrointestinal inflammatory states and classical chronic metabolic diseases such as diabetes. Abnormal glucose metabolism (AGM) after pancreatitis, an exemplar inflammatory disease involving the gastrointestinal tract, is associated with persistent low-grade inflammation and altered secretion of pancreatic and gut hormones as well as cytokines. While GRP is involved in secretion of many of them, it is not known whether GRP has a role in AGM. Therefore, we aimed to investigate the association between GRP and AGM following pancreatitis. Fasting blood samples were collected to measure GRP, blood glucose, insulin, amylin, glucagon, pancreatic polypeptide (PP), somatostatin, cholecystokinin, gastric-inhibitory peptide (GIP), gastrin, ghrelin, glicentin, glucagon-like peptide-1 and 2, oxyntomodulin, peptide YY (PYY), secretin, vasoactive intestinal peptide, tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein (MCP)-1, and interleukin-6. Modified Poisson regression analysis and linear regression analyses were conducted. Four statistical models were used to adjust for demographic, metabolic, and pancreatitis-related risk factors. A total of 83 individuals after an episode of pancreatitis were recruited. GRP was significantly associated with AGM, consistently in all four models (P -trend < 0.05), and fasting blood glucose contributed 17% to the variance of GRP. Further, GRP was significantly associated with glucagon (P < 0.003), MCP-1 (P < 0.025), and TNF-α (P < 0.025) - consistently in all four models. GRP was also significantly associated with PP and PYY in three models (P < 0.030 for both), and with GIP and glicentin in one model (P = 0.001 and 0.024, respectively). Associations between GRP and other pancreatic and gut hormones were not significant. GRP is significantly increased in patients with AGM after pancreatitis and is associated with increased levels of pro

  2. Increased immunogenicity and protective efficacy of influenza M2e fused to a tetramerizing protein.

    Directory of Open Access Journals (Sweden)

    Anne-Marie Carola Andersson

    Full Text Available The ectodomain of the matrix 2 protein (M2e of influenza A virus represents an attractive target for developing a universal influenza A vaccine, with its sequence being highly conserved amongst human variants of this virus. With the aim of targeting conformational epitopes presumably shared by diverse influenza A viruses, a vaccine (M2e-NSP4 was constructed linking M2e (in its consensus sequence to the rotavirus fragment NSP4(98-135; due to its coiled-coil region this fragment is known to form tetramers in aqueous solution and in this manner we hoped to mimick the natural configuration of M2e as presented in membranes. M2e-NSP4 was then evaluated side-by-side with synthetic M2e peptide for its immunogenicity and protective efficacy in a murine influenza challenge model. Here we demonstrate that M2e fused to the tetramerizing protein induces an accelerated, augmented and more broadly reactive antibody response than does M2e peptide as measured in two different assays. Most importantly, vaccination with M2e-NSP4 caused a significant decrease in lung virus load early after challenge with influenza A virus and maintained its efficacy against a lethal challenge even at very low vaccine doses. Based on the results presented in this study M2e-NSP4 merits further investigation as a candidate for or as a component of a universal influenza A vaccine.

  3. Non-destructive evaluation of UV pulse laser-induced damage performance of fused silica optics.

    Science.gov (United States)

    Huang, Jin; Wang, Fengrui; Liu, Hongjie; Geng, Feng; Jiang, Xiaodong; Sun, Laixi; Ye, Xin; Li, Qingzhi; Wu, Weidong; Zheng, Wanguo; Sun, Dunlu

    2017-11-24

    The surface laser damage performance of fused silica optics is related to the distribution of surface defects. In this study, we used chemical etching assisted by ultrasound and magnetorheological finishing to modify defect distribution in a fused silica surface, resulting in fused silica samples with different laser damage performance. Non-destructive test methods such as UV laser-induced fluorescence imaging and photo-thermal deflection were used to characterize the surface defects that contribute to the absorption of UV laser radiation. Our results indicate that the two methods can quantitatively distinguish differences in the distribution of absorptive defects in fused silica samples subjected to different post-processing steps. The percentage of fluorescence defects and the weak absorption coefficient were strongly related to the damage threshold and damage density of fused silica optics, as confirmed by the correlation curves built from statistical analysis of experimental data. The results show that non-destructive evaluation methods such as laser-induced fluorescence and photo-thermal absorption can be effectively applied to estimate the damage performance of fused silica optics at 351 nm pulse laser radiation. This indirect evaluation method is effective for laser damage performance assessment of fused silica optics prior to utilization.

  4. The Spider Venom Peptide Lycosin-II Has Potent Antimicrobial Activity against Clinically Isolated Bacteria

    Directory of Open Access Journals (Sweden)

    Yongjun Wang

    2016-04-01

    Full Text Available Antimicrobial peptides have been accepted as excellent candidates for developing novel antibiotics against drug-resistant bacteria. Recent studies indicate that spider venoms are the source for the identification of novel antimicrobial peptides. In the present study, we isolated and characterized an antibacterial peptide named lycosin-II from the venom of the spider Lycosa singoriensis. It contains 21 amino acid residue lacking cysteine residues and forms a typical linear amphipathic and cationic α-helical conformation. Lycosin-II displays potent bacteriostatic effect on the tested drug-resistant bacterial strains isolated from hospital patients, including multidrug-resistant A. baumannii, which has presented a huge challenge for the infection therapy. The inhibitory ability of lycosin-II might derive from its binding to cell membrane, because Mg2+ could compete with the binding sites to reduce the bacteriostatic potency of lycosin-II. Our data suggest that lycosin-II might be a lead in the development of novel antibiotics for curing drug-resistant bacterial infections.

  5. Pepsin immobilized in dextran-modified fused-silica capillaries for on-line protein digestion and peptide mapping

    Energy Technology Data Exchange (ETDEWEB)

    Stigter, E.C.A. [Division of Biomedical Analysis, Department of Pharmaceutical Sciences, Faculty of Science, Utrecht University, Sorbonnelaan 16, 3584 CA Utrecht (Netherlands)], E-mail: e.c.a.stigter@uu.nl; Jong, G.J. de; Bennekom, W.P. van [Division of Biomedical Analysis, Department of Pharmaceutical Sciences, Faculty of Science, Utrecht University, Sorbonnelaan 16, 3584 CA Utrecht (Netherlands)

    2008-07-07

    On-line digestion of proteins under acidic conditions was studied using micro-reactors consisting of dextran-modified fused-silica capillaries with covalently immobilized pepsin. The proteins used in this study differed in molecular weight, isoelectric point and sample composition. The injected protein samples were completely digested in 3 min and the digest was analyzed with micro-high performance liquid chromatography (HPLC) and tandem mass spectrometry (MS/MS). The different proteins present in the samples could be identified with a Mascot database search on the basis of auto-MS/MS data. It proved also to be possible to digest and analyze protein mixtures with a sequence coverage of 55% and 97% for the haemoglobin {beta}- and {alpha}-chain, respectively, and 35-55% for the various casein variants. Protease auto-digestion, sample carry-over and loss of signal due to adsorption of the injected proteins were not observed. The backpressure of the reactor is low which makes coupling to systems such as Surface Plasmon Resonance biosensors, which do not tolerate too high pressure, possible. The reactor was stable for at least 40 days when used continuously.

  6. Pepsin immobilized in dextran-modified fused-silica capillaries for on-line protein digestion and peptide mapping.

    Science.gov (United States)

    Stigter, E C A; de Jong, G J; van Bennekom, W P

    2008-07-07

    On-line digestion of proteins under acidic conditions was studied using micro-reactors consisting of dextran-modified fused-silica capillaries with covalently immobilized pepsin. The proteins used in this study differed in molecular weight, isoelectric point and sample composition. The injected protein samples were completely digested in 3 min and the digest was analyzed with micro-high performance liquid chromatography (HPLC) and tandem mass spectrometry (MS/MS). The different proteins present in the samples could be identified with a Mascot database search on the basis of auto-MS/MS data. It proved also to be possible to digest and analyze protein mixtures with a sequence coverage of 55% and 97% for the haemoglobin beta- and alpha-chain, respectively, and 35-55% for the various casein variants. Protease auto-digestion, sample carry-over and loss of signal due to adsorption of the injected proteins were not observed. The backpressure of the reactor is low which makes coupling to systems such as Surface Plasmon Resonance biosensors, which do not tolerate too high pressure, possible. The reactor was stable for at least 40 days when used continuously.

  7. A radioimmunoassay of gastric inhibitory polypeptide in human plasma

    International Nuclear Information System (INIS)

    Sarson, D.L.; Bryant, M.G.; Bloom, S.R.

    1980-01-01

    A sensitive radioimmunoassay for the measurement of human gastric inhibitory polypeptide (GIP), using pure porcine GIP, has been developed. Cross-reactivity of the antiserum with all available mammalian gut peptide preparations was negligible with the exception of glucagon when it was approximately 1%. Two major molecular forms of GIP were detectable in plasma and tissue extracts, one of large molecular size and the other corresponding to the elution coefficient of pure porcine standard. Concentrations of GIP in plasma from 50 normal subjects after overnight fasting were 9+-1.0(S.E.M.) pmol/1 rising to a peak of 34+-2.8 pmol/1 following the ingestion of a small mixed test meal. Ingestion of glucose or fat resulted in a similar rise of plasma GIP, whereas no change was observed after the ingestion of protein. (author)

  8. Antibacterial activity of a newly developed peptide-modified lysin against Acinetobacter baumannii and Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Hang eYang

    2015-12-01

    Full Text Available The global emergence of multidrug-resistant (MDR bacteria is a growing threat to public health worldwide. Natural bacteriophage lysins are promising alternatives in the treatment of infections caused by Gram-positive pathogens, but not Gram-negative ones, like Acinetobacter baumannii and Pseudomonas aeruginosa, due to the barriers posed by their outer membranes. Recently, modifying a natural lysin with an antimicrobial peptide was found able to break the barriers, and to kill Gram-negative pathogens. Herein, a new peptide-modified lysin (PlyA was constructed by fusing the cecropin A peptide residues 1–8 (KWKLFKKI with the OBPgp279 lysin and its antibacterial activity was studied. PlyA showed good and broad antibacterial activities against logarithmic phase A. baumannii and P. aeruginosa, but much reduced activities against the cells in stationary phase. Addition of outer membrane permeabilizers (EDTA and citric acid could enhance the antibacterial activity of PlyA against stationary phase cells. Finally, no antibacterial activity of PlyA could be observed in some bio-matrices, such as culture media, milk, and sera. In conclusion, we reported here a novel peptide-modified lysin with significant antibacterial activity against both logarithmic (without OMPs and stationary phase (with OMPs A. baumannii and P. aeruginosa cells in buffer, but further optimization is needed to achieve broad activity in diverse bio-matrices.

  9. Buckwheat trypsin inhibitor with helical hairpin structure belongs to a new family of plant defence peptides.

    Science.gov (United States)

    Oparin, Peter B; Mineev, Konstantin S; Dunaevsky, Yakov E; Arseniev, Alexander S; Belozersky, Mikhail A; Grishin, Eugene V; Egorov, Tsezi A; Vassilevski, Alexander A

    2012-08-15

    A new peptide trypsin inhibitor named BWI-2c was obtained from buckwheat (Fagopyrum esculentum) seeds by sequential affinity, ion exchange and reversed-phase chromatography. The peptide was sequenced and found to contain 41 amino acid residues, with four cysteine residues involved in two intramolecular disulfide bonds. Recombinant BWI-2c identical to the natural peptide was produced in Escherichia coli in a form of a cleavable fusion with thioredoxin. The 3D (three-dimensional) structure of the peptide in solution was determined by NMR spectroscopy, revealing two antiparallel α-helices stapled by disulfide bonds. Together with VhTI, a trypsin inhibitor from veronica (Veronica hederifolia), BWI-2c represents a new family of protease inhibitors with an unusual α-helical hairpin fold. The linker sequence between the helices represents the so-called trypsin inhibitory loop responsible for direct binding to the active site of the enzyme that cleaves BWI-2c at the functionally important residue Arg(19). The inhibition constant was determined for BWI-2c against trypsin (1.7×10(-1)0 M), and the peptide was tested on other enzymes, including those from various insect digestive systems, revealing high selectivity to trypsin-like proteases. Structural similarity shared by BWI-2c, VhTI and several other plant defence peptides leads to the acknowledgement of a new widespread family of plant peptides termed α-hairpinins.

  10. Endodontic therapy for a fused mandibular molar.

    Science.gov (United States)

    Rotstein, I; Moshonov, J; Cohenca, N

    1997-06-01

    Variations in tooth morphology present a clinical challenge when endodontic treatment is required. A case of conservative endodontic therapy for a fused mandibular second and third molar is presented.

  11. FFT-enhanced IHS transform method for fusing high-resolution satellite images

    Science.gov (United States)

    Ling, Y.; Ehlers, M.; Usery, E.L.; Madden, M.

    2007-01-01

    Existing image fusion techniques such as the intensity-hue-saturation (IHS) transform and principal components analysis (PCA) methods may not be optimal for fusing the new generation commercial high-resolution satellite images such as Ikonos and QuickBird. One problem is color distortion in the fused image, which causes visual changes as well as spectral differences between the original and fused images. In this paper, a fast Fourier transform (FFT)-enhanced IHS method is developed for fusing new generation high-resolution satellite images. This method combines a standard IHS transform with FFT filtering of both the panchromatic image and the intensity component of the original multispectral image. Ikonos and QuickBird data are used to assess the FFT-enhanced IHS transform method. Experimental results indicate that the FFT-enhanced IHS transform method may improve upon the standard IHS transform and the PCA methods in preserving spectral and spatial information. ?? 2006 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS).

  12. Modulation of α-synuclein fibrillization by ring-fused 2-pyridones: templation and inhibition involve oligomers with different structure.

    Science.gov (United States)

    Horvath, Istvan; Sellstedt, Magnus; Weise, Christoph; Nordvall, Lina-Maria; Krishna Prasad, G; Olofsson, Anders; Larsson, Göran; Almqvist, Fredrik; Wittung-Stafshede, Pernilla

    2013-04-15

    In a recent study we discovered that a ring-fused 2-pyridone compound triggered fibrillization of a key protein in Parkinson's disease, α-synuclein. To reveal how variations in compound structure affect protein aggregation, we now prepared a number of strategic analogs and tested their effects on α-synuclein amyloid fiber formation in vitro. We find that, in contrast to the earlier templating effect, some analogs inhibit α-synuclein fibrillization. For both templating and inhibiting compounds, the key species formed in the reactions are α-synuclein oligomers that contain compound. Despite similar macroscopic appearance, the templating and inhibiting oligomers are distinctly different in secondary structure content. When the inhibitory oligomers are added in seed amounts, they inhibit fresh α-synuclein aggregation reactions. Our study demonstrates that small chemical changes to the same central fragment can result in opposite effects on protein aggregation. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Formation of active inclusion bodies induced by hydrophobic self-assembling peptide GFIL8.

    Science.gov (United States)

    Wang, Xu; Zhou, Bihong; Hu, Weike; Zhao, Qing; Lin, Zhanglin

    2015-06-16

    In the last few decades, several groups have observed that proteins expressed as inclusion bodies (IBs) in bacteria could still be biologically active when terminally fused to an appropriate aggregation-prone partner such as pyruvate oxidase from Paenibacillus polymyxa (PoxB). More recently, we have demonstrated that three amphipathic self-assembling peptides, an alpha helical peptide 18A, a beta-strand peptide ELK16, and a surfactant-like peptide L6KD, have properties that induce target proteins into active IBs. We have developed an efficient protein expression and purification approach for these active IBs by introducing a self-cleavable intein molecule. In this study, the self-assembling peptide GFIL8 (GFILGFIL) with only hydrophobic residues was analyzed, and this peptide effectively induced the formation of cytoplasmic IBs in Escherichia coli when terminally attached to lipase A and amadoriase II. The protein aggregates in cells were confirmed by transmission electron microscopy analysis and retained ~50% of their specific activities relative to the native counterparts. We constructed an expression and separation coupled tag (ESCT) by incorporating an intein molecule, the Mxe GyrA intein. Soluble target proteins were successfully released from active IBs upon cleavage of the intein between the GFIL8 tag and the target protein, which was mediated by dithiothreitol. A variant of GFIL8, GFIL16 (GFILGFILGFILGFIL), improved the ESCT scheme by efficiently eliminating interference from the soluble intein-GFIL8 molecule. The yields of target proteins at the laboratory scale were 3.0-7.5 μg/mg wet cell pellet, which is comparable to the yields from similar ESCT constructs using 18A, ELK16, or the elastin-like peptide tag scheme. The all-hydrophobic self-assembling peptide GFIL8 induced the formation of active IBs in E. coli when terminally attached to target proteins. GFIL8 and its variant GFIL16 can act as a "pull-down" tag to produce purified soluble proteins with

  14. Hypotensive Effects and Angiotensin-Converting Enzyme Inhibitory Peptides of Reishi (Ganoderma lingzhi Auto-Digested Extract

    Directory of Open Access Journals (Sweden)

    Hai-Bang Tran

    2014-08-01

    Full Text Available Reishi (Ganoderma lingzhi has been used as a traditional medicine for millennia. However, relatively little is known about this mushroom’s proteins and their bioactivities. In this study, we used reishi’s own proteases to hydrolyze its protein and obtained auto-digested reishi (ADR extract. The extract was subjected to in vitro assays and administered to spontaneous hypertensive rats (SHRs to determine its potential for use as a hypotensive medication. Bioassay-guided fractionation and de novo sequencing were used for identifying the active compounds. After 4 h administration of ADR, the systolic pressure of SHRs significantly decreased to 34.3 mmHg (19.5% change and the effect was maintained up to 8 h of administration, with the decrease reaching as low as 26.8 mmHg (15% reduction–compare to base line a decrease of 26.8 mmHg is less than a decrease of 34.3 mmHg so it should give a smaller % reduction. Eleven peptides were identified and four of them showed potent inhibition against ACE with IC50 values ranging from 73.1 μM to 162.7 μM. The results showed that ADR could be a good source of hypotensive peptides that could be used for antihypertensive medication or incorporation into functional foods.

  15. Efficient refolding and immobilization of PMMA-tag-fused single-chain Fv antibodies for sensitive immunological detection on a PMMA plate.

    Science.gov (United States)

    Kumada, Yoichi; Ishikawa, Yasuyuki; Fujiwara, Yusuke; Takeda, Rui; Miyamoto, Ryosuke; Niwa, Daisuke; Momose, Shun; Kang, Bongmun; Kishimoto, Michimasa

    2014-09-01

    In this study, we investigated the efficient refolding and site-specific immobilization of single-chain variable fragments (scFvs) genetically fused with a poly(methylmethacrylate)-binding peptide (PMMA-tag). According to the results of an aggregation test of a scFv-PM in the presence of 0.5 M urea, aggregation was hardly detectable at a weak-alkaline pH (8.5) with lower concentrations of NaCl. Consequently, more than 93% recovery of the anti-RNase scFv-PM model was attained, when it was refolded by dialysis against 50 mM TAPS (pH8.5). These results suggested that the apparent isoelectric point (pI) of a target scFv was decreased to a great extent by the genetic fusion of a PMMA-tag containing 5 acidic amino acids, and, thus, the solubility of the scFv-PM in its semi-denatured form was considerably improved. We also designed alternative peptide-tags composed of plural aspartic acid residues (D5, D10 and D15-tags) to decrease the apparent pI value of the fusion protein. As a consequence, scFv-D5, scFv-D10 and scFv-D15 were also efficiently refolded with yields of more than 95%. It is noteworthy that even scFv-PS-D15, which had both a positively charged polystyrene-binding peptide (PS-tag) and a negatively charged D15-tag, was serially connected at the C-terminal region of scFvs, and also refolded with a yield of 96.1%. These results clearly indicate that controlling the apparent pI value of scFvs by the fusion of oligo-peptides composed of acidic amino acids at the C-terminus resulted in a high degree of recovery via dialysis refolding. According to the results of a sandwich ELISA using scFv-PMs, scFv-D15 and scFv-PS-D15 as ligands, high antigen-binding signals were detected from both the PMMA and phi-PS plates immobilized with scFv-PMs. Furthermore, the high antigen-binding activity of scFv-PMs was maintained in an adsorption state when it was immobilized on the surface of not only PMMA, but also hydrophilic PS (phi-PS) and polycarbonate (PC). These results

  16. Rational Design of Cyclic Antimicrobial Peptides Based on BPC194 and BPC198

    Directory of Open Access Journals (Sweden)

    Anna D. Cirac

    2017-06-01

    Full Text Available A strategy for the design of antimicrobial cyclic peptides derived from the lead compounds c(KKLKKFKKLQ (BPC194 and c(KLKKKFKKLQ (BPC198 is reported. First, the secondary β-structure of BPC194 and BPC198 was analyzed by carrying out molecular dynamics (MD simulations. Then, based on the sequence pattern and the β-structure of BPC194 or BPC198, fifteen analogues were designed and synthesized on solid-phase. The best peptides (BPC490, BPC918, and BPC924 showed minimum inhibitory concentration (MIC values <6.2 μM against Pseudomonas syringae pv. syringae and Xanthomonas axonopodis pv. vesicatoria, and an MIC value of 12.5 to 25 μM against Erwinia amylovora, being as active as BPC194 and BPC198. Interestingly, these three analogues followed the structural pattern defined from the MD simulations of the parent peptides. Thus, BPC490 maintained the parallel alignment of the hydrophilic pairs K1–K8, K2–K7, and K4–K5, whereas BPC918 and BPC924 included the two hydrophilic interactions K3–Q10 and K5–K8. In short, MD simulations have proved to be very useful for ascertaining the structural features of cyclic peptides that are crucial for their biological activity. Such approaches could be further employed for the development of new antibacterial cyclic peptides.

  17. Colored fused filament fabrication

    OpenAIRE

    Song, Haichuan; Lefebvre, Sylvain

    2017-01-01

    Filament fused fabrication is the method of choice for printing 3D models at low cost, and is the de-facto standard for hobbyists, makers and schools. Unfortunately, filament printers cannot truly reproduce colored objects. The best current techniques rely on a form of dithering exploiting occlusion, that was only demonstrated for shades of two base colors and that behaves differently depending on surface slope. We explore a novel approach for 3D printing colored objects, capable of creating ...

  18. Isolation and molecular characterization of porcine calcitonin gene-related peptide (CGRP) and its endocrine effects in the porcine pancreas

    DEFF Research Database (Denmark)

    Rasmussen, T N; Bersani, M; Schmidt, P

    1998-01-01

    was found in the two tissues. The adrenal peptide was sequenced and found to differ from human alpha-CGRP at six positions and from human beta-CGRP at three positions. By immunohistochemistry, CGRP was found in nerve fibers in the pancreatic ganglia. A synthetic replica of the porcine peptide was infused...... significantly by 10(-8) M CGRP. In immunoneutralization studies (n = 6) using a high-affinity somatostatin antibody, the inhibitory effect of CGRP at 10(-8) M was reversed to a significant stimulation of insulin and glucagon secretion. Insulin secretion in response to square-wave increases in glucose...

  19. Structure-activity-based design of a synthetic malaria peptide eliciting sporozoite inhibitory antibodies in a virosomal formulation.

    NARCIS (Netherlands)

    Okitsu, S.L.; Kienzl, U.; Moehle, K.; Silvie, O.; Peduzzi, E.; Mueller, M.S.; Sauerwein, R.W.; Matile, H.; Zurbriggen, R.; Mazier, D.; Robinson, J.A.; Pluschke, G.

    2007-01-01

    The circumsporozoite protein (CSP) of Plasmodium falciparum is a leading candidate antigen for inclusion in a malaria subunit vaccine. We describe here the design of a conformationally constrained synthetic peptide, designated UK-39, which has structural and antigenic similarity to the NPNA-repeat

  20. Efficient secretory expression of recombinant proteins in Escherichia coli with a novel actinomycete signal peptide.

    Science.gov (United States)

    Cui, Yanbing; Meng, Yiwei; Zhang, Juan; Cheng, Bin; Yin, Huijia; Gao, Chao; Xu, Ping; Yang, Chunyu

    2017-01-01

    In well-established heterologous hosts, such as Escherichia coli, recombinant proteins are usually intracellular and frequently found as inclusion bodies-especially proteins possessing high rare codon content. In this study, successful secretory expression of three hydrolases, in a constructed inducible or constitutive system, was achieved by fusion with a novel signal peptide (Kp-SP) from an actinomycete. The signal peptide efficiently enabled extracellular protein secretion and also contributed to the active expression of the intracellular recombinant proteins. The thermophilic α-amylase gene of Bacillus licheniformis was fused with Kp-SP. Both recombinants, carrying inducible and constitutive plasmids, showed remarkable increases in extracellular and intracellular amylolytic activity. Amylase activity was observed to be > 10-fold in recombinant cultures with the constitutive plasmid, pBSPPc, compared to that in recombinants lacking Kp-SP. Further, the signal peptide enabled efficient secretion of a thermophilic cellulase into the culture medium, as demonstrated by larger halo zones and increased enzymatic activities detected in both constructs from different plasmids. For heterologous proteins with a high proportion of rare codons, it is difficult to obtain high expression in E. coli owing to the codon bias. Here, the fusion of an archaeal homologue of the amylase encoding gene, FSA, with Kp-SP resulted in > 5-fold higher extracellular activity. The successful extracellular expression of the amylase indicated that the signal peptide also contributed significantly to its active expression and signified the potential value of this novel and versatile signal peptide in recombinant protein production. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Venom-derived peptides inhibiting Kir channels: Past, present, and future.

    Science.gov (United States)

    Doupnik, Craig A

    2017-12-01

    Inwardly rectifying K + (Kir) channels play a significant role in vertebrate and invertebrate biology by regulating the movement of K + ions involved in membrane transport and excitability. Yet unlike other ion channels including their ancestral K + -selective homologs, there are very few venom toxins known to target and inhibit Kir channels with the potency and selectivity found for the Ca 2+ -activated and voltage-gated K + channel families. It is unclear whether this is simply due to a lack of discovery, or instead a consequence of the evolutionary processes that drive the development of venom components towards their targets based on a collective efficacy to 1) elicit pain for defensive purposes, 2) promote paralysis for prey capture, or 3) facilitate delivery of venom components into the circulation. The past two decades of venom screening has yielded three venom peptides with inhibitory activity towards mammalian Kir channels, including the discovery of tertiapin, a high-affinity pore blocker from the venom of the European honey bee Apis mellifera. Venomics and structure-based computational approaches represent exciting new frontiers for venom peptide development, where re-engineering peptide 'scaffolds' such as tertiapin may aid in the quest to expand the palette of potent and selective Kir channel blockers for future research and potentially new therapeutics. This article is part of the Special Issue entitled 'Venom-derived Peptides as Pharmacological Tools.' Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Fungal Systematics and Evolution: FUSE 1

    NARCIS (Netherlands)

    Crous, Pedro W; Schumacher, René K; Wingfield, Michael J; Lombard, Lorenzo; Giraldo, Alejandra; Christensen, Martha; Gardiennet, Alain; Nakashima, Chiharu; Pereira, Olinto L; Smith, Alexander J; Groenewald, Johannes Z

    2015-01-01

    Fungal Systematics and Evolution (FUSE) is introduced as a new series to expedite the publication of issues relating to the epitypification of formerly described species, report new sexual-asexual connections, the merging of sexual and asexual gen¬era following the end of dual nomenclature, and to

  3. Reverse engineering truncations of an antimicrobial peptide dimer to identify the origins of potency and broad spectrum of action.

    Science.gov (United States)

    Anantharaman, Aparna; Sahal, Dinkar

    2010-08-26

    Antimicrobial peptides hold promise against antibiotic resistant pathogens. Here, to find the physicochemical origins of potency and broad spectrum antimicrobial action, we report the structure-activity relationships of synthetic intermediates (peptides A-D) of a potent lysine branched dimeric antibacterial peptide DeltaFd. Our studies show that a tetracationic character in a weak helical fold (peptide C) elicits potent but narrow spectrum antimicrobial activity [Minimum inhibitory concentrations (MICs) E. coli 10 microM, S. aureus>100 microM]. In contrast, a hexacationic character in a strong, amphipathic helix (DeltaFd) confers potent and broad spectrum action [MICs E. coli 2.5 microM, S. aureus 5 microM]. While DeltaFd caused rapid and potent permeabilization of the E. coli membranes, the less helical intermediates (peptides A-D) showed slow and weak to no responses. Two seminal findings that may aid future drug design are (a) at identical helicity, increasing charge enhanced outer membrane permeabilization, and (b) at identical charge, increasing helicity stimulated rate of outer membrane permeabilization and kill kinetics besides enhancing potency leading to broad spectrum action.

  4. Synthetic Peptides Derived from Bovine Lactoferricin Exhibit Antimicrobial Activity against E. coli ATCC 11775, S. maltophilia ATCC 13636 and S. enteritidis ATCC 13076.

    Science.gov (United States)

    Huertas Méndez, Nataly De Jesús; Vargas Casanova, Yerly; Gómez Chimbi, Anyelith Katherine; Hernández, Edith; Leal Castro, Aura Lucia; Melo Diaz, Javier Mauricio; Rivera Monroy, Zuly Jenny; García Castañeda, Javier Eduardo

    2017-03-12

    Linear, dimeric, tetrameric, and cyclic peptides derived from lactoferricin B-containing non-natural amino acids and the RWQWR motif were synthesized, purified, and characterized using RP-HPLC, MALDI-TOF mass spectrometry, and circular dichroism. The antibacterial activity of peptides against Escherichia coli ATCC 11775, Stenotrophomonas maltophilia ATCC 13636, and Salmonella enteritidis ATCC 13076 was evaluated. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. The synthetic bovine lactoferricin exhibited antibacterial activity against E. coli ATCC 11775 and S. enteritidis ATCC 13076. The dimeric peptide (RRWQWR)₂K-Ahx exhibited the highest antibacterial activity against the tested bacterial strain. The monomeric, cyclic, tetrameric, and palindromic peptides containing the RWQWR motif exhibited high and specific activity against E. coli ATCC 11775. The results suggest that short peptides derived from lactoferricin B could be considered as potential candidates for the development of antibacterial agents against infections caused by E. coli .

  5. Relationships between Cargo, Cell Penetrating Peptides and Cell Type for Uptake of Non-Covalent Complexes into Live Cells

    Directory of Open Access Journals (Sweden)

    Andrea-Anneliese Keller

    2013-02-01

    Full Text Available Modulating signaling pathways for research and therapy requires either suppression or expression of selected genes or internalization of proteins such as enzymes, antibodies, nucleotide binding proteins or substrates including nucleoside phosphates and enzyme inhibitors. Peptides, proteins and nucleotides are transported by fusing or conjugating them to cell penetrating peptides or by formation of non-covalent complexes. The latter is often preferred because of easy handling, uptake efficiency and auto-release of cargo into the live cell. In our studies complexes are formed with labeled or readily detectable cargoes for qualitative and quantitative estimation of their internalization. Properties and behavior of adhesion and suspension vertebrate cells as well as the protozoa Leishmania tarentolae are investigated with respect to proteolytic activity, uptake efficiency, intracellular localization and cytotoxicity. Our results show that peptide stability to membrane-bound, secreted or intracellular proteases varies between different CPPs and that the suitability of individual CPPs for a particular cargo in complex formation by non-covalent interactions requires detailed studies. Cells vary in their sensitivity to increasing concentrations of CPPs. Thus, most cells can be efficiently transduced with peptides, proteins and nucleotides with intracellular concentrations in the low micromole range. For each cargo, cell type and CPP the optimal conditions must be determined separately.

  6. Oil Palm Defensin: A Thermal Stable Peptide that Restricts the Mycelial Growth of Ganoderma boninense.

    Science.gov (United States)

    Tan, Yung-Chie; Ang, Cheng-Liang; Wong, Mui-Yun; Ho, Chai-Ling

    2016-01-01

    Plant defensins are plant defence peptides that have many different biological activities, including antifungal, antimicrobial, and insecticidal activities. A cDNA (EgDFS) encoding defensin was isolated from Elaeis guineensis. The open reading frame of EgDFS contained 231 nucleotides encoding a 71-amino acid protein with a predicted molecular weight at 8.69 kDa, and a potential signal peptide. The eight highly conserved cysteine sites in plant defensins were also conserved in EgDFS. The EgDFS sequence lacking 30 amino acid residues at its N-terminus (EgDFSm) was cloned into Escherichia coli BL21 (DE3) pLysS and successfully expressed as a soluble recombinant protein. The recombinant EgDFSm was found to be a thermal stable peptide which demonstrated inhibitory activity against the growth of G. boninense possibly by inhibiting starch assimilation. The role of EgDFSm in oil palm defence system against the infection of pathogen G. boninense was discussed.

  7. Activity of Genital Tract Secretions and Synthetic Antimicrobial Peptides against Group B Streptococcus.

    Science.gov (United States)

    Agarwal, Nidhi; Buckley, Niall; Nakra, Natasha; Gialanella, Philip; Yuan, Weirong; Ghartey, Jeny P

    2015-12-01

    Genital tract secretions inhibit Escherichia coli (E. coli) through antimicrobial peptides (AMP) secreted by the host and vaginal microbiota. However, there are limited data against group B Streptococcus (GBS). Group B Streptococcus were incubated with cervico-vaginal lavage (CVL) samples from healthy non-pregnant women (n = 12) or synthetic AMP and monitored for bacterial growth using a turbidimetric approach. E. coli inhibitory activity was determined by a colony-forming unit assay. None of the CVL samples inhibited GBS. The human neutrophil peptide-1 and human defensin 5 inhibited GBS growth by ≥80% at concentrations ≥20 μg/mL and ≥50 μg/mL, respectively, while human beta-defensin 2 and LL-37 did not inhibit at highest concentration tested (100 μg/mL). In contrast, all AMP inhibited E. coli. Antimicrobial peptides may protect against E. coli colonization but have more limited activity against GBS. Future studies will focus on augmenting host defense with specific AMP to prevent genitourinary infection with these pathogenic organisms. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Bioactive Peptides in Cereals and Legumes: Agronomical, Biochemical and Clinical Aspects

    Directory of Open Access Journals (Sweden)

    Marco Malaguti

    2014-11-01

    Full Text Available Cereals and legumes are key components of a healthy and balanced diet. Accordingly, many national nutritional guidelines emphasize their health promoting properties by placing them at the base of nutritional food pyramids. This concept is further validated by the observed correlation between a lower risk and occurrence of chronic diseases and the adherence to dietary patterns, like the Mediterranean diet, in which cereal grains, legumes and derived products represent a staple food. In the search for a dietary approach to control/prevent chronic degenerative diseases, protein derived bioactive peptides may represent one such source of health-enhancing components. These peptides may already be present in foods as natural components or may derive from hydrolysis by chemical or enzymatic treatments (digestion, hydrolysis or fermentation. Many reports are present in the literature regarding the bioactivity of peptides in vitro and a wide range of activities has been described, including antimicrobial properties, blood pressure-lowering (ACE inhibitory effects, cholesterol-lowering ability, antithrombotic and antioxidant activities, enhancement of mineral absorption/bioavailability, cyto- or immunomodulatory effects, and opioid-like activities. However it is difficult to translate these observed effects to human. In fact, the active peptide may be degraded during digestion, or may not be absorbed or reach the target tissues at a concentration necessary to exert its function. This review will focus on bioactive peptides identified in cereals and legumes, from an agronomical and biochemical point of view, including considerations about requirements for the design of appropriate clinical trials necessary for the assessment of their nutraceutical effect in vivo.

  9. Mapping membrane activity in undiscovered peptide sequence space using machine learning.

    Science.gov (United States)

    Lee, Ernest Y; Fulan, Benjamin M; Wong, Gerard C L; Ferguson, Andrew L

    2016-11-29

    There are some ∼1,100 known antimicrobial peptides (AMPs), which permeabilize microbial membranes but have diverse sequences. Here, we develop a support vector machine (SVM)-based classifier to investigate ⍺-helical AMPs and the interrelated nature of their functional commonality and sequence homology. SVM is used to search the undiscovered peptide sequence space and identify Pareto-optimal candidates that simultaneously maximize the distance σ from the SVM hyperplane (thus maximize its "antimicrobialness") and its ⍺-helicity, but minimize mutational distance to known AMPs. By calibrating SVM machine learning results with killing assays and small-angle X-ray scattering (SAXS), we find that the SVM metric σ correlates not with a peptide's minimum inhibitory concentration (MIC), but rather its ability to generate negative Gaussian membrane curvature. This surprising result provides a topological basis for membrane activity common to AMPs. Moreover, we highlight an important distinction between the maximal recognizability of a sequence to a trained AMP classifier (its ability to generate membrane curvature) and its maximal antimicrobial efficacy. As mutational distances are increased from known AMPs, we find AMP-like sequences that are increasingly difficult for nature to discover via simple mutation. Using the sequence map as a discovery tool, we find a unexpectedly diverse taxonomy of sequences that are just as membrane-active as known AMPs, but with a broad range of primary functions distinct from AMP functions, including endogenous neuropeptides, viral fusion proteins, topogenic peptides, and amyloids. The SVM classifier is useful as a general detector of membrane activity in peptide sequences.

  10. Therapeutic Fc-fusion proteins and peptides as successful alternatives to antibodies.

    Science.gov (United States)

    Beck, Alain; Reichert, Janice M

    2011-01-01

    Therapeutic antibodies have captured substantial attention due to the relatively high rate at which these products reach marketing approval, and the subsequent commercial success they frequently achieve. In the 2000s, a total of 20 antibodies (18 full-length IgG and 2 Fab) were approved by the Food and Drug Administration (FDA) or European Medicines Agency (EMA). In the 2010s to date, an additional 3 antibodies (denosumab, belimumab, ipilimumab) have been approved and one antibody-drug conjugate (brentuximab vedotin) is undergoing regulatory review and may be approved in the US by August 30, 2011. However, a less heralded group of antibody-based therapeutics comprising proteins or peptides fused with an Fc is following the success of classical antibodies.

  11. Host defense peptides of thrombin modulate inflammation and coagulation in endotoxin-mediated shock and Pseudomonas aeruginosa sepsis.

    Science.gov (United States)

    Kalle, Martina; Papareddy, Praveen; Kasetty, Gopinath; Mörgelin, Matthias; van der Plas, Mariena J A; Rydengård, Victoria; Malmsten, Martin; Albiger, Barbara; Schmidtchen, Artur

    2012-01-01

    Gram-negative sepsis is accompanied by a disproportionate innate immune response and excessive coagulation mainly induced by endotoxins released from bacteria. Due to rising antibiotic resistance and current lack of other effective treatments there is an urgent need for new therapies. We here present a new treatment concept for sepsis and endotoxin-mediated shock, based on host defense peptides from the C-terminal part of human thrombin, found to have a broad and inhibitory effect on multiple sepsis pathologies. Thus, the peptides abrogate pro-inflammatory cytokine responses to endotoxin in vitro and in vivo. Furthermore, they interfere with coagulation by modulating contact activation and tissue factor-mediated clotting in vitro, leading to normalization of coagulation responses in vivo, a previously unknown function of host defense peptides. In a mouse model of Pseudomonas aeruginosa sepsis, the peptide GKY25, while mediating a modest antimicrobial effect, significantly inhibited the pro-inflammatory response, decreased fibrin deposition and leakage in the lungs, as well as reduced mortality. Taken together, the capacity of such thrombin-derived peptides to simultaneously modulate bacterial levels, pro-inflammatory responses, and coagulation, renders them attractive therapeutic candidates for the treatment of invasive infections and sepsis.

  12. Host defense peptides of thrombin modulate inflammation and coagulation in endotoxin-mediated shock and Pseudomonas aeruginosa sepsis.

    Directory of Open Access Journals (Sweden)

    Martina Kalle

    Full Text Available Gram-negative sepsis is accompanied by a disproportionate innate immune response and excessive coagulation mainly induced by endotoxins released from bacteria. Due to rising antibiotic resistance and current lack of other effective treatments there is an urgent need for new therapies. We here present a new treatment concept for sepsis and endotoxin-mediated shock, based on host defense peptides from the C-terminal part of human thrombin, found to have a broad and inhibitory effect on multiple sepsis pathologies. Thus, the peptides abrogate pro-inflammatory cytokine responses to endotoxin in vitro and in vivo. Furthermore, they interfere with coagulation by modulating contact activation and tissue factor-mediated clotting in vitro, leading to normalization of coagulation responses in vivo, a previously unknown function of host defense peptides. In a mouse model of Pseudomonas aeruginosa sepsis, the peptide GKY25, while mediating a modest antimicrobial effect, significantly inhibited the pro-inflammatory response, decreased fibrin deposition and leakage in the lungs, as well as reduced mortality. Taken together, the capacity of such thrombin-derived peptides to simultaneously modulate bacterial levels, pro-inflammatory responses, and coagulation, renders them attractive therapeutic candidates for the treatment of invasive infections and sepsis.

  13. Characterization of Peptides Found in Unprocessed and Extruded Amaranth (Amaranthus hypochondriacus Pepsin/Pancreatin Hydrolysates

    Directory of Open Access Journals (Sweden)

    Alvaro Montoya-Rodríguez

    2015-04-01

    Full Text Available The objectives of this study were to characterize peptides found in unprocessed amaranth hydrolysates (UAH and extruded amaranth hydrolysates (EAH and to determine the effect of the hydrolysis time on the profile of peptides produced. Amaranth grain was extruded in a single screw extruder at 125 °C of extrusion temperature and 130 rpm of screw speed. Unprocessed and extruded amaranth flour were hydrolyzed with pepsin/pancreatin enzymes following a kinetic at 10, 25, 60, 90, 120 and 180 min for each enzyme. After 180 min of pepsin hydrolysis, aliquots were taken at each time during pancreatin hydrolysis to characterize the hydrolysates by MALDI-TOF/MS-MS. Molecular masses (MM (527, 567, 802, 984, 1295, 1545, 2034 and 2064 Da of peptides appeared consistently during hydrolysis, showing high intensity at 10 min (2064 Da, 120 min (802 Da and 180 min (567 Da in UAH. EAH showed high intensity at 10 min (2034 Da and 120 min (984, 1295 and 1545 Da. Extrusion produced more peptides with MM lower than 1000 Da immediately after 10 min of hydrolysis. Hydrolysis time impacted on the peptide profile, as longer the time lower the MM in both amaranth hydrolysates. Sequences obtained were analyzed for their biological activity at BIOPEP, showing important inhibitory activities related to chronic diseases. These peptides could be used as a food ingredient/supplement in a healthy diet to prevent the risk to develop chronic diseases.

  14. 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.

  15. Nondestructive detection system of faults in fuses using radioisotope

    International Nuclear Information System (INIS)

    Goncalves, D.

    1973-01-01

    A system is developed to show the viability of non-destructive detection of the faults of explosive safety fuses which are manufactured by Fabrica da Estrela do Ministerio do Exercito. The faults are detected by an ion-chamber based on the variation of the intensity of the beta particles that penetrate the fuse which passes through a collimator. The beta particles are emitted by Strontium-90 + Yttrium-90 encapsulated in either stainless steel or aluminum. The concept of 'bucking Voltage' is applied to differentiate electronically the signal generated by the ion-chamber. (author)

  16. In vitro angiotensin I converting enzyme inhibition by a peptide isolated from Chiropsalmus quadrigatus Haeckel (box jellyfish) venom hydrolysate.

    Science.gov (United States)

    So, Pamela Berilyn T; Rubio, Peter; Lirio, Stephen; Macabeo, Allan Patrick; Huang, Hsi-Ya; Corpuz, Mary Jho-Anne T; Villaflores, Oliver B

    2016-09-01

    The anti-angiotensin I converting enzyme activity of box jellyfish, Chiropsalmus quadrigatus Haeckel venom hydrolysate was studied. The venom extract was obtained by centrifugation and ultrasonication. Protein concentration of 12.99 μg/mL was determined using Bradford assay. The pepsin and papain hydrolysate was tested for its toxicity by Limit test following the OECD Guideline 425 using 5 female Sprague-Dawley rats. Results showed that the hydrolysate is nontoxic with an LD50 above 2000 mg/kg. In vitro angiotensin I converting enzyme (ACE) inhibitory activity was determined using ACE kit-WST. Isolation of ACE inhibitory peptides using column chromatography with SP-Sephadex G-25 yielded 8 pooled fractions with fraction 3 (86.5%) exhibiting the highest activity. This was followed by reverse phase - high performance liquid chromatography (RP-HPLC) with an octadecyl silica column (Inertsil ODS-3) using methanol:water 15:85 at a flow rate of 1.0 mL/min. Among the 13 fractions separated with the RP-HPLC, fraction 3.5 exhibited the highest ACE inhibitory activity (84.1%). The peptide sequence ACPGPNPGRP (IC50 2.03 μM) from fraction 3.5 was identified using Matrix-assisted laser desorption/ionization with time-of-flight tandem mass spectroscopy analysis (MALDI-TOF/MS). Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Measurements of fuse and resistor characteristics for multi-megajoule capacitor bank application

    International Nuclear Information System (INIS)

    McDonald, K.F.; Smith, T.; Golden, J.; Conley, B.

    1986-01-01

    Experimental tests have been conducted on commercially available fuses and resistors under fast high voltage pulsed (10 μsec) conditions to determine their ability to protect capacitor bank components during faults. NRL's Modified Betatron Accelerator uses two multi-megajoule capacitor banks to power the toroidal and betatron magnetic field coils. The expensive high energy density capacitors in these banks must be protected from excessive peak current, voltage reversal, or charging beyond their electrical ratings in the occurrence of a fault. Adequate protection can be obtained with fuses and resistors in series with each parallel connected capacitor. The fuses must open reliably and hold off high voltage D.C. (10 - 20 kV), and the resistors must conduct high current and di/dt without failing from energy deposition or magnetic forces. The performance of the commercial fuses is well documented at low AC frequencies and currents (60 Hz/100 A) but data was not previously available for the fast high current pulsed conditions that prevail under actual fault conditions. A 20 kV 200 kJ, low inductance capacitor bank and ignitron switch were used to conduct the experiments. Peak currents in the fuses were approximately 170 kA at t - 6.5 μs. The final fuse hold-off voltage exceeded 8 kV. Currents in the resistors ranged from - 20 - 40 kA per resistor. The experimental results have been compared to the manufacturers data from minimum melt and maximum let-through and to exploding bridge wire computer models

  18. 30 CFR 75.601-3 - Short circuit protection; dual element fuses; current ratings; maximum values.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Short circuit protection; dual element fuses... Trailing Cables § 75.601-3 Short circuit protection; dual element fuses; current ratings; maximum values. Dual element fuses having adequate current-interrupting capacity shall meet the requirements for short...

  19. Anthracene-fused BODIPYs as near-infrared dyes with high photostability

    KAUST Repository

    Zeng, Lintao; Jiao, Chongjun; Huang, Xiaobo; Huang, Kuo-Wei; Chin, Weeshong; Wu, Jishan

    2011-01-01

    An anthracene unit was successfully fused to the zigzag edge of a boron dipyrromethene (BODIPY) core by an FeCl 3-mediated oxidative cyclodehydrogenation reaction. Meanwhile, a dimer was also formed by both intramolecular cyclization and intermolecular coupling. The anthracene-fused BODIPY monomer 7a and dimer 7b showed small energy gaps (∼1.4 eV) and near-infrared absorption/emission. Moreover, they exhibited high photostability. © 2011 American Chemical Society.

  20. Anthracene-fused BODIPYs as near-infrared dyes with high photostability

    KAUST Repository

    Zeng, Lintao

    2011-11-18

    An anthracene unit was successfully fused to the zigzag edge of a boron dipyrromethene (BODIPY) core by an FeCl 3-mediated oxidative cyclodehydrogenation reaction. Meanwhile, a dimer was also formed by both intramolecular cyclization and intermolecular coupling. The anthracene-fused BODIPY monomer 7a and dimer 7b showed small energy gaps (∼1.4 eV) and near-infrared absorption/emission. Moreover, they exhibited high photostability. © 2011 American Chemical Society.

  1. The role of brain peptides in the reproduction of blue gourami males (Trichogaster trichopterus).

    Science.gov (United States)

    Levy, Gal; Degani, Gad

    2013-10-01

    In all vertebrates, reproduction and growth are closely linked and both are controlled by complex hormonal interactions at the brain-pituitary level. In this study, we focused on the reciprocal interactions between brain peptides that regulate growth and reproductive functions in a teleostei fish (blue gourami Trichogaster trichopterus). An increase in gonadotropin-releasing hormone 1 (GnRH1) gene expression was detected during ontogeny, and this peptide increased growth hormone (GH) and β follicle-stimulating hormone (βFSH) gene expression in pituitary cell culture. However, although no change in gonadotropin-releasing hormone 2 (GnRH2) gene expression during the reproductive cycle or sexual behavior was detected, a stimulatory effect of this peptide on β gonadotropins (βGtH) gene expression was observed. In addition, pituitary adenylate cyclase-activating polypeptide 38 (PACAP-38) inhibited GnRH-analog-induced βFSH gene expression, and co-treatment of cells with GnRH-analog and PACAP-38 inhibited GnRH-analog-stimulatory and PACAP-38-inhibitory effects on GH gene expression. These findings together with previous studies were used to create a model summarizing the mechanism of brain peptides (GnRH, PACAP and its related peptide) and the relationship to reproduction and growth through pituitary hormone gene expression during ontogenesis and reproductive stages in blue gourami. © 2013 Wiley Periodicals, Inc.

  2. 30 CFR 75.601-2 - Short circuit protection; use of fuses; approval by the Secretary.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Short circuit protection; use of fuses... Trailing Cables § 75.601-2 Short circuit protection; use of fuses; approval by the Secretary. Fuses shall not be employed to provide short circuit protection for trailing cables unless specifically approved...

  3. Identification of a haemolysin-like peptide with antibacterial activity using the draft genome sequence of Staphylococcus epidermidis strain A487.

    Science.gov (United States)

    Al-Mahrous, Mohammed M; Jack, Ralph W; Sandiford, Stephanie K; Tagg, John R; Beatson, Scott A; Upton, Mathew

    2011-08-01

    Our interest in Staphylococcus epidermidis strain A487 was prompted by the unusual nature of its inhibitory activity in screening tests against methicillin-resistant Staphylococcus aureus isolates. The inhibitory activity was detected in deferred antagonism tests only if the agar plate was preheated for at least 35 min at ≥ 55 °C before inoculation of the indicator bacteria, this phenomenon indicating possible involvement of a heat-labile immunity agent or protease. The inhibitor was purified to homogeneity by ammonium sulphate precipitation, followed by cation-exchange and reversed-phase chromatography. Tandem MS revealed a novel peptide of molecular weight 2588.4 Da. The draft genome sequence of strain A487 was determined using 454 GS FLX technology, allowing the identification of the structural gene (hlp) encoding the mature peptide MQFITDLIKKAVDFFKGLFGNK. The deduced amino acid sequence of peptide 487 exhibited 70.8% similarity to that of a putative haemolysin from Staphylococcus cohnii. Analysis of the genome of strain A487 showed several additional inhibitor-encoding genes, including hld, the determinant for staphylococcal δ-lysin. This work indicates that potentially useful inhibitors could be overlooked in agar-based inhibitor screening programmes lacking a heat pretreatment step and also highlights the utility of draft genome sequence examination in antibacterial agent discovery. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  4. Extraction and identification of α-amylase inhibitor peptides from Nephelium lappacheum and Nephelium mutabile seed protein using gastro-digestive enzymes.

    Science.gov (United States)

    Evaristus, Natashya Anak; Wan Abdullah, Wan Nadiah; Gan, Chee-Yuen

    2018-04-01

    The potential of N. lappacheum and N. mutabile seed as a source of α-amylase inhibitor peptides was explored based on the local traditional practice of using the seed. Different gastro-digestive enzymes (i.e. pepsin or chymotrypsin) or a sequential digestion were used to extract the peptides. The effects of digestion time and enzyme to substrate (E:S) ratio on the α-amylase inhibitory activity were investigated. Results showed that chymotrypsin was effective in producing the inhibitor peptides from rambutan seed protein at E:S ratio 1:20 for 1 h, whereas pepsin was more effective for pulasan seed protein under the same condition. A total of 20 and 31 novel inhibitor peptides were identified, respectively. These peptides could bind with the subsites of α-amylase (i.e. Trp58, Trp59, Tyr62, Asp96, Arg195, Asp197, Glu233, His299, Asp300, and His305) and formed a sliding barrier that preventing the formation of enzyme/substrate intermediate leading to lower α-amylase activity. Copyright © 2018 Elsevier Inc. All rights reserved.

  5. In vitro chemopreventive properties of peptides released from quinoa (Chenopodium quinoa Willd.) protein under simulated gastrointestinal digestion.

    Science.gov (United States)

    Vilcacundo, Rubén; Miralles, Beatriz; Carrillo, Wilman; Hernández-Ledesma, Blanca

    2018-03-01

    Because of the continuous and direct interaction between the digestive tract and foods, dietary compounds represent an interesting source of chemopreventive agents for gastrointestinal health. In this study, the influence of a standardized static in vitro gastrointestinal digestion model on the release of peptides with chemopreventive potential from quinoa protein was investigated. Gastroduodenal digests and fractions collected by ultrafiltration were evaluated for their in plate oxygen radical absorbance capacity and in vitro colon cancer cell viability inhibitory activity. Highest effects were observed in the digests obtained during the intestinal phase, with fraction containing peptides 5kDa showing the greatest anti-cancer effects. Seventeen potential bioactive peptides derived from quinoa proteins have been identified. These proteins might be utilized as new ingredients in the development of functional foods or nutraceuticals with the aim of reducing oxidative stress-associated diseases, including cancer. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. The Cyclic Antibacterial Peptide Enterocin AS-48: Isolation, Mode of Action, and Possible Food Applications

    OpenAIRE

    Grande Burgos, Mar?a Jos?; P?rez Pulido, Rub?n; L?pez Aguayo, Mar?a del Carmen; G?lvez, Antonio; Lucas, Rosario

    2014-01-01

    Enterocin AS-48 is a circular bacteriocin produced by Enterococcus. It contains a 70 amino acid-residue chain circularized by a head-to-tail peptide bond. The conformation of enterocin AS-48 is arranged into five alpha-helices with a compact globular structure. Enterocin AS-48 has a wide inhibitory spectrum on Gram-positive bacteria. Sensitivity of Gram-negative bacteria increases in combination with outer-membrane permeabilizing treatments. Eukaryotic cells are bacteriocin-resistant. This ...

  7. The gonadotropin-inhibitory hormone (Lpxrfa) system's regulation of reproduction in the brain-pituitary axis of the zebrafish (Danio rerio).

    Science.gov (United States)

    Spicer, Olivia Smith; Zmora, Nilli; Wong, Ten-Tsao; Golan, Matan; Levavi-Sivan, Berta; Gothilf, Yoav; Zohar, Yonathan

    2017-05-01

    Gonadotropin-inhibitory hormone (GNIH) was discovered in quail with the ability to reduce gonadotropin expression/secretion in the pituitary. There have been few studies on GNIH orthologs in teleosts (LPXRFamide (Lpxrfa) peptides), which have provided inconsistent results. Therefore, the goal of this study was to determine the roles and modes of action by which Lpxrfa exerts its functions in the brain-pituitary axis of zebrafish (Danio rerio). We localized Lpxrfa soma to the ventral hypothalamus, with fibers extending throughout the brain and to the pituitary. In the preoptic area, Lpxrfa fibers interact with gonadotropin-releasing hormone 3 (Gnrh3) soma. In pituitary explants, zebrafish peptide Lpxrfa-3 downregulated luteinizing hormone beta subunit and common alpha subunit expression. In addition, Lpxrfa-3 reduced gnrh3 expression in brain slices, offering another pathway for Lpxrfa to exert its effects on reproduction. Receptor activation studies, in a heterologous cell-based system, revealed that all three zebrafish Lpxrfa peptides activate Lpxrf-R2 and Lpxrf-R3 via the PKA/cAMP pathway. Receptor activation studies demonstrated that, in addition to activating Lpxrf receptors, zebrafish Lpxrfa-2 and Lpxrfa-3 antagonize Kisspeptin-2 (Kiss2) activation of Kisspeptin receptor-1a (Kiss1ra). The fact that kiss1ra-expressing neurons in the preoptic area are innervated by Lpxrfa-ir fibers suggests an additional pathway for Lpxrfa action. Therefore, our results suggest that Lpxrfa may act as a reproductive inhibitory neuropeptide in the zebrafish that interacts with Gnrh3 neurons in the brain and with gonadotropes in the pituitary, while also potentially utilizing the Kiss2/Kiss1ra pathway. © The Authors 2017. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. Carriers of the TCF7L2 rs7903146 TT genotype have elevated levels of plasma glucose, serum proinsulin and plasma gastric inhibitory polypeptide (GIP) during a meal test

    DEFF Research Database (Denmark)

    Gjesing, A P; Kjems, L L; Vestmar, M A

    2011-01-01

    , proinsulin, insulin, C-peptide, glucagon, glucagon-like peptide-1 (GLP-1), glucagon-like peptide-2 (GLP-2) and gastric inhibitory polypeptide (GIP) among individuals carrying the high-risk rs7903146 TT genotype and low-risk CC genotype following a meal test. Methods A meal challenge was performed in 31......, 45, 60, 75, 90, 105, 120, 135, 150, 180, 210, and 240 min after ingestion of a standardised breakfast meal. Results An elevated incremental AUC for plasma glucose was observed among TT genotype carriers (CC carriers 21.8¿±¿101.9 mmol/l¿×¿min vs TT carriers 97.9¿±¿89.2 mmol/l¿×¿min, p¿=¿0.001). TT...

  9. A fusion-inhibiting peptide against Rift Valley fever virus inhibits multiple, diverse viruses.

    Directory of Open Access Journals (Sweden)

    Jeffrey W Koehler

    Full Text Available For enveloped viruses, fusion of the viral envelope with a cellular membrane is critical for a productive infection to occur. This fusion process is mediated by at least three classes of fusion proteins (Class I, II, and III based on the protein sequence and structure. For Rift Valley fever virus (RVFV, the glycoprotein Gc (Class II fusion protein mediates this fusion event following entry into the endocytic pathway, allowing the viral genome access to the cell cytoplasm. Here, we show that peptides analogous to the RVFV Gc stem region inhibited RVFV infectivity in cell culture by inhibiting the fusion process. Further, we show that infectivity can be inhibited for diverse, unrelated RNA viruses that have Class I (Ebola virus, Class II (Andes virus, or Class III (vesicular stomatitis virus fusion proteins using this single peptide. Our findings are consistent with an inhibition mechanism similar to that proposed for stem peptide fusion inhibitors of dengue virus in which the RVFV inhibitory peptide first binds to both the virion and cell membranes, allowing it to traffic with the virus into the endocytic pathway. Upon acidification and rearrangement of Gc, the peptide is then able to specifically bind to Gc and prevent fusion of the viral and endocytic membranes, thus inhibiting viral infection. These results could provide novel insights into conserved features among the three classes of viral fusion proteins and offer direction for the future development of broadly active fusion inhibitors.

  10. Synthetic Peptides Derived from Bovine Lactoferricin Exhibit Antimicrobial Activity against E. coli ATCC 11775, S. maltophilia ATCC 13636 and S. enteritidis ATCC 13076

    Directory of Open Access Journals (Sweden)

    Nataly De Jesús Huertas Méndez

    2017-03-01

    Full Text Available Linear, dimeric, tetrameric, and cyclic peptides derived from lactoferricin B–containing non-natural amino acids and the RWQWR motif were synthesized, purified, and characterized using RP-HPLC, MALDI-TOF mass spectrometry, and circular dichroism. The antibacterial activity of peptides against Escherichia coli ATCC 11775, Stenotrophomonas maltophilia ATCC 13636, and Salmonella enteritidis ATCC 13076 was evaluated. The minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC were determined. The synthetic bovine lactoferricin exhibited antibacterial activity against E. coli ATCC 11775 and S. enteritidis ATCC 13076. The dimeric peptide (RRWQWR2K-Ahx exhibited the highest antibacterial activity against the tested bacterial strain. The monomeric, cyclic, tetrameric, and palindromic peptides containing the RWQWR motif exhibited high and specific activity against E. coli ATCC 11775. The results suggest that short peptides derived from lactoferricin B could be considered as potential candidates for the development of antibacterial agents against infections caused by E. coli.

  11. Expression of recombinant antibacterial lactoferricin-related peptides from Pichia pastoris expression system.

    Science.gov (United States)

    Chen, Gen-Hung; Chen, Wei-Ming; Huang, Guo-Ting; Chen, Yu-Wen; Jiang, Shann-Tzong

    2009-10-28

    Four recombinant antimicrobial peptide (rAMP) cDNAs, constructed from two goat lactoferricin-related peptide cDNAs (GLFcin and GLFcin II) with/without (His)(6)-Tag, were cloned into pPICZalphaC and transformed into Pichia pastoris SMD1168H. After methanol induction, these rAMPs were expressed and secreted into broth. They were purified after CM-Sepharose (without His-tg), HisTrap (with His-tg) and Sephadex G-25 chromatographies. The yield of purified rAMP was 0.15 mg/mL of broth. These 4 rAMPs were thermal-stable and with high antibacterial activity against Escherichia coli BCRC 11549, Pseudomonas aeruginosa BCRC 12450, Bacillus cereus BCRC 10603, Staphylococcus aureus BCRC 25923, Propioni bacterium acnes BCRC 10723, and Listera monocytogenes BCRC 14845. The minimum inhibitory concentration (MIC) of rAMPs against these indicators ranged from 4.07 to 16.00 mg/mL.

  12. 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.

  13. Crossed fused renal ectopia: Challenges in diagnosis and management

    Directory of Open Access Journals (Sweden)

    Shailesh Solanki

    2013-01-01

    Full Text Available Aim: Crossed fused renal ectopia is a rare congenital malformation, which is reported to be usually asymptomatic but may have varied presentations. This survey was conducted to study the clinical profile and the challenges posed in the management of this entity. Materials and Methods: Retrospective analysis of 6 patients diagnosed to have crossed fused renal ectopia during 1997-2010. The diagnosis was confirmed during surgical exploration in one patient. In one patient it was detected on antenatal ultrasonography and in the other 4 patients it was detected during investigations for abdominal pain, abdominal mass, anorectal malformation and urinary tract infection. Results: The left moiety was crossed and fused with the right moiety in 4 cases. Ultrasonography was found to be a good screening investigation with useful diagnostic contributions from CT scans, radionuclide scintigraphy and magnetic resonance urography. Micturating cystourethrography revealed presence of VUR in 4 cases, 3 of whom have undergone ureteric reimplantation. Two patients required pyeloplasty for pelviureteric junction obstruction; in one of these patients the upper ureter was entrapped in the isthmus. In one patient, a non-functioning moiety resulted in nephrectomy. All children were asymptomatic at last follow-up with stable renal functions. Conclusions: Crossed fused renal ectopia was detected in most patients during investigation for other problems. It was found more commonly in boys. The left moiety was crossed to the right in the majority of cases. Associated urological problems were found in most cases and required the appropriate surgical management.

  14. Inhibition of serotonin release by bombesin-like peptides in rat hypothalamus in vitro

    International Nuclear Information System (INIS)

    Saporito, M.S.; Warwick, R.O. Jr.

    1989-01-01

    We investigated the activity of bombesin (BN), neuromedin-C (NM-C) and neuromedin-B (NM-B) on serotonin (5-HT) release and reuptake in rat hypothalamus (HYP) in vitro. BN and NM-C but not NM-B decreased K + evoked 3 H-5-HT release from superfused HYP slices by 25%. Bacitracin, a nonspecific peptidase inhibitor, reversed the inhibitory effect of BN on K + evoked 3 H-5-HT release. Phosphoramidon (PAN, 10 μM) an endopeptidase 24.11 inhibitor, abolished the inhibitory effect of BN, but not NM-C, on K + evoked 3 H-5-HT release. The peptidyl dipeptidase A inhibitor enalaprilat (ENP, 10 μM), enhanced both BN and NM-C inhibition of 3 H-5-HT release. Bestatin (BST, 10 μM) had no effect on BN or NM-C inhibitory activity on 3 H-5-HT release. Neither BN, NM-C nor NM-B affected reuptake of 3 H-5-HT into HYP synaptosomes alone or in combination with any of the peptidase inhibitors, nor did these peptides alter the ability of fluoxetine to inhibit 3 H-5-HT uptake

  15. Down-regulation of histamine-induced endothelial cell activation as potential anti-atherosclerotic activity of peptides from Spirulina maxima.

    Science.gov (United States)

    Vo, Thanh-Sang; Kim, Se-Kwon

    2013-10-09

    Histamine, a potent inflammatory mediator, has been known to cause the pathogenesis of atherosclerosis. In this sense, two bioactive peptides P1 (LDAVNR; 686Da) and P2 (MMLDF; 655Da) purified from gastric enzymatic hydrolysate of Spirulina maxima were examined for their protective effects against early atherosclerotic responses induced by histamine in EA.hy926 endothelial cells. Interestingly, both P1 and P2 exhibited inhibitory activities on the production and expression of IL-6 and MCP-1. Furthermore, P1 and P2 inhibited the production of adhesion molecules including P-selectin and E-selectin, and thus reducing in vitro cell adhesion of monocyte onto endothelial cells. In addition, the production of intracellular reactive oxygen species was observed to reduce in the presence of P1 or P2. Notably, the inhibitory activities of P1 and P2 were found due to down-regulating Egr-1 expression via histamine receptor and PKCδ-dependent MAPKs activation pathway. These results suggest that peptides P1 and P2 from S. maxima are effective to suppress histamine-induced endothelial cell activation that may contribute to the prevention of early atherosclerosis. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Material Considerations for Fused-Filament Fabrication of Solid Dosage Forms

    Directory of Open Access Journals (Sweden)

    Evert Fuenmayor

    2018-04-01

    Full Text Available Material choice is a fundamental consideration when it comes to designing a solid dosage form. The matrix material will ultimately determine the rate of drug release since the physical properties (solubility, viscosity, and more of the material control both fluid ingress and disintegration of the dosage form. The bulk properties (powder flow, concentration, and more of the material should also be considered since these properties will influence the ability of the material to be successfully manufactured. Furthermore, there is a limited number of approved materials for the production of solid dosage forms. The present study details the complications that can arise when adopting pharmaceutical grade polymers for fused-filament fabrication in the production of oral tablets. The paper also presents ways to overcome each issue. Fused-filament fabrication is a hot-melt extrusion-based 3D printing process. The paper describes the problems encountered in fused-filament fabrication with Kollidon® VA64, which is a material that has previously been utilized in direct compression and hot-melt extrusion processes. Formulation and melt-blending strategies were employed to increase the printability of the material. The paper defines for the first time the essential parameter profile required for successful 3D printing and lists several pre-screening tools that should be employed to guide future material formulation for the fused-filament fabrication of solid dosage forms.

  17. Inhibitory interneuron progenitor transplantation restores normal learning and memory in ApoE4 knock-in mice without or with Aβ accumulation.

    Science.gov (United States)

    Tong, Leslie M; Djukic, Biljana; Arnold, Christine; Gillespie, Anna K; Yoon, Seo Yeon; Wang, Max M; Zhang, Olivia; Knoferle, Johanna; Rubenstein, John L R; Alvarez-Buylla, Arturo; Huang, Yadong

    2014-07-16

    Excitatory and inhibitory balance of neuronal network activity is essential for normal brain function and may be of particular importance to memory. Apolipoprotein (apo) E4 and amyloid-β (Aβ) peptides, two major players in Alzheimer's disease (AD), cause inhibitory interneuron impairments and aberrant neuronal activity in the hippocampal dentate gyrus in AD-related mouse models and humans, leading to learning and memory deficits. To determine whether replacing the lost or impaired interneurons rescues neuronal signaling and behavioral deficits, we transplanted embryonic interneuron progenitors into the hippocampal hilus of aged apoE4 knock-in mice without or with Aβ accumulation. In both conditions, the transplanted cells developed into mature interneurons, functionally integrated into the hippocampal circuitry, and restored normal learning and memory. Thus, restricted hilar transplantation of inhibitory interneurons restores normal cognitive function in two widely used AD-related mouse models, highlighting the importance of interneuron impairments in AD pathogenesis and the potential of cell replacement therapy for AD. More broadly, it demonstrates that excitatory and inhibitory balance are crucial for learning and memory, and suggests an avenue for investigating the processes of learning and memory and their alterations in healthy aging and diseases. Copyright © 2014 the authors 0270-6474/14/349506-10$15.00/0.

  18. High-Speed Fuses in IGBT based Voltage Source Converters

    DEFF Research Database (Denmark)

    Iov, Florin; Blaabjerg, Frede; Rasmussen, Henrik

    2005-01-01

    The demand for protection of power electronic applications has during the last couple of years increased regarding the high-power IGBT modules. Even with an active protection, a high power IGBT still has a risk of exhibiting a violent rupture in the case of a fault if IGBT fuses do not protect it...... protection. First, the problem of adding inductance in the DC-link circuit is treated, second a short discussion of the protection of the IGBT module is done, and finally, the impact of the high frequency loading on the current carrying capability of the fuses is presented....

  19. Modelling and Analysis of Proximity Effect in IGBT Fuses

    DEFF Research Database (Denmark)

    Iov, Florin; Blaabjerg, Frede; Rasmussen, Henrik

    2005-01-01

    The demand for protection of power electronic applications has during the last couple of years increased regarding the high-power IGBT modules. The consequences of electrical faults can be severe in special cases; not only on the equipment but also to people, if safety principles are not applied....... Even with an active protection, a high power IGBT still has a risk of exhibiting a violent rupture in the case of a fault if e.g. IGBT fuses are not protecting it. By introducing fuses into voltage source converters a better protection of IGBT's can be achieved. However, skin and proximity effects...

  20. Phospho-dependent binding of the clathrin AP2 adaptor complex to GABAA receptors regulates the efficacy of inhibitory synaptic transmission.

    Science.gov (United States)

    Kittler, Josef T; Chen, Guojun; Honing, Stephan; Bogdanov, Yury; McAinsh, Kristina; Arancibia-Carcamo, I Lorena; Jovanovic, Jasmina N; Pangalos, Menelas N; Haucke, Volker; Yan, Zhen; Moss, Stephen J

    2005-10-11

    The efficacy of synaptic inhibition depends on the number of gamma-aminobutyric acid type A receptors (GABA(A)Rs) expressed on the cell surface of neurons. The clathrin adaptor protein 2 (AP2) complex is a critical regulator of GABA(A)R endocytosis and, hence, surface receptor number. Here, we identify a previously uncharacterized atypical AP2 binding motif conserved within the intracellular domains of all GABA(A)R beta subunit isoforms. This AP2 binding motif (KTHLRRRSSQLK in the beta3 subunit) incorporates the major sites of serine phosphorylation within receptor beta subunits, and phosphorylation within this site inhibits AP2 binding. Furthermore, by using surface plasmon resonance, we establish that a peptide (pepbeta3) corresponding to the AP2 binding motif in the GABA(A)R beta3 subunit binds to AP2 with high affinity only when dephosphorylated. Moreover, the pepbeta3 peptide, but not its phosphorylated equivalent (pepbeta3-phos), enhanced the amplitude of miniature inhibitory synaptic current and whole cell GABA(A)R current. These effects of pepbeta3 on GABA(A)R current were occluded by inhibitors of dynamin-dependent endocytosis supporting an action of pepbeta3 on GABA(A)R endocytosis. Therefore phospho-dependent regulation of AP2 binding to GABA(A)Rs provides a mechanism to specify receptor cell surface number and the efficacy of inhibitory synaptic transmission.

  1. Sequential Multicomponent Strategy for the Diastereoselective Synthesis of Densely Functionalized Spirooxindole-Fused Thiazolidines

    NARCIS (Netherlands)

    Rainoldi, Giulia; Begnini, Fabio; De Munnik, Mariska; Lo Presti, Leonardo; Vande Velde, Christophe M.L.; Orru, Romano; Lesma, Giordano; Ruijter, Eelco; Silvani, Alessandra

    2018-01-01

    We developed two Ugi-type three-component reactions of spirooxindole-fused 3-thiazolines, isocyanides, and either carboxylic acids or trimethylsilyl azide, to give highly functionalized spirooxindole-fused thiazolidines. Two diverse libraries were generated using practical and robust procedures

  2. Recycling potential for low voltage and high voltage high rupturing capacity fuse links.

    Science.gov (United States)

    Psomopoulos, Constantinos S; Barkas, Dimitrios A; Kaminaris, Stavros D; Ioannidis, George C; Karagiannopoulos, Panagiotis

    2017-12-01

    Low voltage and high voltage high-rupturing-capacity fuse links are used in LV and HV installations respectively, protecting mainly the LV and HV electricity distribution and transportation networks. The Waste Electrical and Electronic Equipment Directive (2002/96/EC) for "Waste of electrical and electronic equipment" is the main related legislation and as it concerns electrical and electronic equipment, it includes electric fuses. Although, the fuse links consist of recyclable materials, only small scale actions have been implemented for their recycling around Europe. This work presents the possibilities for material recovery from this specialized industrial waste for which there are only limited volume data. Furthermore, in order to present the huge possibilities and environmental benefits, it presents the potential for recycling of HRC fuses used by the Public Power Corporation of Greece, which is the major consumer for the country, but one of the smallest ones in Europe and globally, emphasizing in this way in the issue. According to the obtained results, fuse recycling could contribute to the effort for minimize the impacts on the environment through materials recovery and reduction of the wastes' volume disposed of in landfills. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Inducible Expression of the De-Novo Designed Antimicrobial Peptide SP1-1 in Tomato Confers Resistance to Xanthomonas campestris pv. vesicatoria.

    Directory of Open Access Journals (Sweden)

    Areli Herrera Diaz

    Full Text Available Antimicrobial peptides (AMPs are small peptides with less than 50 amino acids and are part of the innate immune response in almost all organisms, including bacteria, vertebrates, invertebrates and plants. AMPs are active against a broad-spectrum of pathogens. The inducible expression of AMPs in plants is a promising approach to combat plant pathogens with minimal negative side effects, such as phytotoxicity or infertility. In this study, inducible expression of the de-novo designed AMP SP1-1 in Micro Tom tomato protected tomato fruits against bacterial spot disease caused by Xanthomonas campestris pv. vesicatoria. The peptide SP1-1 was targeted to the apoplast which is the primary infection site for plant pathogens, by fusing SP1-1 peptide to the signal peptide RsAFP1 of radish (Raphanus sativus. The pathogen inducibility of the expression was enabled by using an optimized inducible 4XW2/4XS promoter. As a result, the tomato fruits of independently generated SP1-1 transgenic lines were significantly more resistant to X. campestris pv. vesicatoria than WT tomato fruits. In transgenic lines, bacterial infection was reduced up to 65% in comparison to the infection of WT plants. Our study demonstrates that the combination of the 4XW2/4XS cis-element from parsley with the synthetic antimicrobial peptide SP1-1 is a good alternative to protect tomato fruits against infections with X. campestris pv. vesicatoria.

  4. Cyclic peptide inhibitors of the β-sliding clamp in Staphylococcus aureus

    DEFF Research Database (Denmark)

    Kjelstrup, Susanne; Hansen, Paula Melo Paulon; Thomsen, Line Elnif

    2013-01-01

    Interaction between pairs of Staphylococcus aureus replication proteins was detected in an Escherichia coli based two-hybrid analysis. A reverse two-hybrid system was constructed for selection of compounds that hindered interaction between interacting protein pairs. A number of cyclic peptides, f....... The minimum inhibitory concentration was ∼50 μg/ml for S. aureus cells. These compounds may serve as lead candidates for future development into novel classes of antibiotics as well as provide information on the function of the S. aureus replication process....

  5. Enhancement of laser induced damage threshold of fused silica by acid etching combined with UV laser conditioning

    International Nuclear Information System (INIS)

    Chen Meng; Xiang Xia; Jiang Yong; Zu Xiaotao; Yuan Xiaodong; Zheng Wanguo; Wang Haijun; Li Xibin; Lu Haibing; Jiang Xiaodong; Wang Chengcheng

    2010-01-01

    Acid etching combined with UV laser conditioning is developed to enhance the laser induced damage threshold (LIDT) of fused silica. Firstly, the fused silica is etched for 1 ∼ 100 min with a buffered 1% HF solution. After acid etching, its transmittance, surface roughness and LIDT are measured. The results reveal that the fused silica has the highest LIDT and transmittance after etching for 10 min. Then UV laser (355 nm) conditioning is adopted to process the 10-min-etched fused silica. When the laser fluence is below 60% of fused silica's zero probability damage threshold, the LIDT increases gradually with the increase of laser conditioning fluence. However, the LIDT rapidly decreases to be lower than the threshold of the 10-min-etched fused silica when the conditioning fluence is up to 80% of the threshold. Proper acid etching and laser conditioning parameters will effectively enhance the laser damage resistance of fused silica. (authors)

  6. Combined Kernel-Based BDT-SMO Classification of Hyperspectral Fused Images

    Directory of Open Access Journals (Sweden)

    Fenghua Huang

    2014-01-01

    Full Text Available To solve the poor generalization and flexibility problems that single kernel SVM classifiers have while classifying combined spectral and spatial features, this paper proposed a solution to improve the classification accuracy and efficiency of hyperspectral fused images: (1 different radial basis kernel functions (RBFs are employed for spectral and textural features, and a new combined radial basis kernel function (CRBF is proposed by combining them in a weighted manner; (2 the binary decision tree-based multiclass SMO (BDT-SMO is used in the classification of hyperspectral fused images; (3 experiments are carried out, where the single radial basis function- (SRBF- based BDT-SMO classifier and the CRBF-based BDT-SMO classifier are used, respectively, to classify the land usages of hyperspectral fused images, and genetic algorithms (GA are used to optimize the kernel parameters of the classifiers. The results show that, compared with SRBF, CRBF-based BDT-SMO classifiers display greater classification accuracy and efficiency.

  7. Hydrophobic and electrostatic interactions between cell penetrating peptides and plasmid DNA are important for stable non-covalent complexation and intracellular delivery.

    Science.gov (United States)

    Upadhya, Archana; Sangave, Preeti C

    2016-10-01

    Cell penetrating peptides are useful tools for intracellular delivery of nucleic acids. Delivery of plasmid DNA, a large nucleic acid, poses a challenge for peptide mediated transport. The paper investigates and compares efficacy of five novel peptide designs for complexation of plasmid DNA and subsequent delivery into cells. The peptides were designed to contain reported DNA condensing agents and basic cell penetrating sequences, octa-arginine (R 8 ) and CHK 6 HC coupled to cell penetration accelerating peptides such as Bax inhibitory mutant peptide (KLPVM) and a peptide derived from the Kaposi fibroblast growth factor (kFGF) membrane translocating sequence. A tryptophan rich peptide, an analogue of Pep-3, flanked with CH 3 on either ends was also a part of the study. The peptides were analysed for plasmid DNA complexation, protection of peptide-plasmid DNA complexes against DNase I, serum components and competitive ligands by simple agarose gel electrophoresis techniques. Hemolysis of rat red blood corpuscles (RBCs) in the presence of the peptides was used as a measure of peptide cytotoxicity. Plasmid DNA delivery through the designed peptides was evaluated in two cell lines, human cervical cancer cell line (HeLa) and (NIH/3 T3) mouse embryonic fibroblasts via expression of the secreted alkaline phosphatase (SEAP) reporter gene. The importance of hydrophobic sequences in addition to cationic sequences in peptides for non-covalent plasmid DNA complexation and delivery has been illustrated. An alternative to the employment of fatty acid moieties for enhanced gene transfer has been proposed. Comparison of peptides for plasmid DNA complexation and delivery of peptide-plasmid DNA complexes to cells estimated by expression of a reporter gene, SEAP. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

  8. Peptides and Anti-peptide Antibodies for Small and Medium Scale Peptide and Anti-peptide Affinity Microarrays: Antigenic Peptide Selection, Immobilization, and Processing.

    Science.gov (United States)

    Zhang, Fan; Briones, Andrea; Soloviev, Mikhail

    2016-01-01

    This chapter describes the principles of selection of antigenic peptides for the development of anti-peptide antibodies for use in microarray-based multiplex affinity assays and also with mass-spectrometry detection. The methods described here are mostly applicable to small to medium scale arrays. Although the same principles of peptide selection would be suitable for larger scale arrays (with 100+ features) the actual informatics software and printing methods may well be different. Because of the sheer number of proteins/peptides to be processed and analyzed dedicated software capable of processing all the proteins and an enterprise level array robotics may be necessary for larger scale efforts. This report aims to provide practical advice to those who develop or use arrays with up to ~100 different peptide or protein features.

  9. Design and characterization of hirulogs: A novel class of bivalent peptide inhibitors of thrombin

    Energy Technology Data Exchange (ETDEWEB)

    Maraganore, J.M.; Bourdon, P.; Jablonski, J.; Ramachandran, K.L. (Biogen, Inc., Cambridge, MA (USA)); Fenton, J.W. II (New York State Department of Health, Albany (USA))

    1990-07-31

    A novel class of synthetic peptides has been designed that inhibit the thrombin catalytic site and exhibit specificity for the anion-binding exosite (ABE) of {alpha}-thrombin. These peptides, called hirulogs, consist of (i) an active-site specificity sequence with a restricted Arg-Pro scissile bond, (ii) a polymeric linker of glycyl residues from 6 to 18 {angstrom} in length, and (iii) an ABE recognition sequence such as that in the hirudin C-terminus. Hirulog-1 ((D-Phe)-Pro-Arg-Pro-(Gly){sub 4}-Asn-Gly-Asp-Phe-Glu-Glu-Ile-Pro-Glu-Tyr-Leu) inhibits the thrombin-catalyzed hydrolysis of a tripeptide p-nitroanilide substrate with K{sub i} = 2.3 nM. In contrast, the synthetic C-terminal hirudin peptide S-Hir{sub 53-64}, which binds to the thrombin ABE, blocked the fibrinogen clotting activity of the enzyme with K{sub i} = 144 nM but failed to inhibit the hydrolysis of p-nitroanilide substrates at concentrations as high as 1 mM. Hirulog-1, but not S-Hir{sub 53-64}, was found to inhibit the incorporation of ({sup 14}C)diisopropyl fluorophosphate in thrombin. Hirulog-1 appears specific for thrombin as it lacks inhibitory activities toward human factor Xa, human plasmin, and bovine trypsin at inhibitor:enzyme concentrations 3 orders of magnitude higher than those required to inhibit thrombin. The optimal inhibitory activity of hirulog-1 depends upon all three components of its structure. Comparison of anticoagulant activities of hirulog-1, hirudin, and S-Hir{sub 53-64} showed that the synthetic hirulog-1 is 2-fold more potent than hirudin and 100-fold more active than S-Hir{sub 53-64} in increasing the activated partial thromboplastin time of normal human plasma.

  10. Search for stress dependence in the internal friction of fused silica

    International Nuclear Information System (INIS)

    Willems, Phil; Lamb, Corinne; Heptonstall, Alastair; Hough, Jim

    2003-01-01

    The quality factor (Q) of the vertical bounce mode of a fused silica fiber pendulum is measured at high and low stresses. The internal friction of fused silica fibers is found to be independent of stress from 12.8 to 213 MPa at a level of 1.6x10 -8 . Comparison with Q's of fiber bending modes is consistent with losses concentrated in the surface of the fiber

  11. Effects of the TAT peptide orientation and relative location on the protein transduction efficiency.

    Science.gov (United States)

    Guo, Qingguo; Zhao, Guojie; Hao, Fengjin; Guan, Yifu

    2012-05-01

    To understand the protein transduction domain (PTD)-mediated protein transduction behavior and to explore its potential in delivering biopharmaceutic drugs, we prepared four TAT-EGFP conjugates: TAT(+)-EGFP, TAT(-)-EGFP, EGFP-TAT(+) and EGFP-TAT(-), where TAT(+) and TAT(-) represent the original and the reversed TAT sequence, respectively. These four TAT-EGFP conjugates were incubated with HeLa and PC12 cells for in vitro study as well as injected intraperitoneally to mice for in vivo study. Flow cytometric results showed that four TAT-EGFP conjugates were able to traverse HeLa and PC12 cells with almost equal transduction efficiency. The in vivo study showed that the TAT-EGFP conjugates could be delivered into different organs of mice with different transduction capabilities. Bioinformatic analyses and CD spectroscopic data revealed that the TAT peptide has no defined secondary structure, and conjugating the TAT peptide to the EGFP cargo protein would not alter the native structure and the function of the EGFP protein. These results conclude that the sequence orientation, the spatial structure, and the relative location of the TAT peptide have much less effect on the TAT-mediated protein transduction. Thus, the TAT-fused conjugates could be constructed in more convenient and flexible formats for a wide range of biopharmaceutical applications. © 2011 John Wiley & Sons A/S.

  12. Factors affecting antimicrobial activity of MUC7 12-mer, a human salivary mucin-derived peptide

    Directory of Open Access Journals (Sweden)

    Bobek Libuse A

    2007-11-01

    Full Text Available Abstract Background MUC7 12-mer (RKSYKCLHKRCR, a cationic antimicrobial peptide derived from the human low-molecular-weight salivary mucin MUC7, possesses potent antimicrobial activity in vitro. In order to evaluate the potential therapeutic application of the MUC7 12-mer, we examined the effects of mono- and divalent cations, EDTA, pH, and temperature on its antimicrobial activity. Methods Minimal Inhibitory Concentrations (MICs were determined using a liquid growth inhibition assay in 96-well microtiter plates. MUC7 12-mer was added at concentrations of 1.56–50 μM. MICs were determined at three endpoints: MIC-0, MIC-1, and MIC-2 (the lowest drug concentration showing 10%, 25% and 50% of growth, respectively. To examine the effect of salts or EDTA, a checkerboard microdilution technique was used. Fractional inhibitory concentration index (FICi was calculated on the basis of MIC-0. The viability of microbial cells treated with MUC7 12-mer in the presence of sodium or potassium was also determined by killing assay or flow cytometry. Results The MICs of MUC7 12-mer against organisms tested ranged from 6.25–50 μM. For C. albicans, antagonism (FICi 4.5 was observed for the combination of MUC7 12-mer and calcium; however, there was synergism (FICi 0.22 between MUC7 12-mer and EDTA, and the synergism was retained in the presence of calcium at its physiological concentration (1–2 mM. No antagonism but additivity or indifference (FICi 0.55–2.5 was observed for the combination of MUC7 12-mer and each K+, Na+, Mg2+, or Zn2+. MUC7 12-mer peptide (at 25 μM also exerted killing activity in the presence of NaCl, (up to 25 mM for C. albicans and up to 150 mM for E. coli, a physiological concentration of sodium in the oral cavity and serum, respectively and retained candidacidal activity in the presence of KCl (up to 40 mM. The peptide exhibited higher inhibitory activity against C. albicans at pH 7, 8, and 9 than at pH 5 and 6, and temperature up to

  13. Fusing simulation and experiment: The effect of mutations on the structure and activity of the influenza fusion peptide

    Science.gov (United States)

    Lousa, Diana; Pinto, Antónia R. T.; Victor, Bruno L.; Laio, Alessandro; Veiga, Ana S.; Castanho, Miguel A. R. B.; Soares, Cláudio M.

    2016-01-01

    During the infection process, the influenza fusion peptide (FP) inserts into the host membrane, playing a crucial role in the fusion process between the viral and host membranes. In this work we used a combination of simulation and experimental techniques to analyse the molecular details of this process, which are largely unknown. Although the FP structure has been obtained by NMR in detergent micelles, there is no atomic structure information in membranes. To answer this question, we performed bias-exchange metadynamics (BE-META) simulations, which showed that the lowest energy states of the membrane-inserted FP correspond to helical-hairpin conformations similar to that observed in micelles. BE-META simulations of the G1V, W14A, G12A/G13A and G4A/G8A/G16A/G20A mutants revealed that all the mutations affect the peptide’s free energy landscape. A FRET-based analysis showed that all the mutants had a reduced fusogenic activity relative to the WT, in particular the mutants G12A/G13A and G4A/G8A/G16A/G20A. According to our results, one of the major causes of the lower activity of these mutants is their lower membrane affinity, which results in a lower concentration of peptide in the bilayer. These findings contribute to a better understanding of the influenza fusion process and open new routes for future studies. PMID:27302370

  14. Identification of conformational epitopes for human IgG on Chemotaxis inhibitory protein of Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Furebring Christina

    2009-03-01

    Full Text Available Abstract Background The Chemotaxis inhibitory protein of Staphylococcus aureus (CHIPS blocks the Complement fragment C5a receptor (C5aR and formylated peptide receptor (FPR and is thereby a potent inhibitor of neutrophil chemotaxis and activation of inflammatory responses. The majority of the healthy human population has antibodies against CHIPS that have been shown to interfere with its function in vitro. The aim of this study was to define potential epitopes for human antibodies on the CHIPS surface. We also initiate the process to identify a mutated CHIPS molecule that is not efficiently recognized by preformed anti-CHIPS antibodies and retains anti-inflammatory activity. Results In this paper, we panned peptide displaying phage libraries against a pool of CHIPS specific affinity-purified polyclonal human IgG. The selected peptides could be divided into two groups of sequences. The first group was the most dominant with 36 of the 48 sequenced clones represented. Binding to human affinity-purified IgG was verified by ELISA for a selection of peptide sequences in phage format. For further analysis, one peptide was chemically synthesized and antibodies affinity-purified on this peptide were found to bind the CHIPS molecule as studied by ELISA and Surface Plasmon Resonance. Furthermore, seven potential conformational epitopes responsible for antibody recognition were identified by mapping phage selected peptide sequences on the CHIPS surface as defined in the NMR structure of the recombinant CHIPS31–121 protein. Mapped epitopes were verified by in vitro mutational analysis of the CHIPS molecule. Single mutations introduced in the proposed antibody epitopes were shown to decrease antibody binding to CHIPS. The biological function in terms of C5aR signaling was studied by flow cytometry. A few mutations were shown to affect this biological function as well as the antibody binding. Conclusion Conformational epitopes recognized by human antibodies

  15. Structure of the complex between teicoplanin and a bacterial cell-wall peptide: use of a carrier-protein approach

    International Nuclear Information System (INIS)

    Economou, Nicoleta J.; Zentner, Isaac J.; Lazo, Edwin; Jakoncic, Jean; Stojanoff, Vivian; Weeks, Stephen D.; Grasty, Kimberly C.; Cocklin, Simon; Loll, Patrick J.

    2013-01-01

    Using a carrier-protein strategy, the structure of teicoplanin bound to its bacterial cell-wall target has been determined. The structure reveals the molecular determinants of target recognition, flexibility in the antibiotic backbone and intrinsic radiation sensitivity of teicoplanin. Multidrug-resistant bacterial infections are commonly treated with glycopeptide antibiotics such as teicoplanin. This drug inhibits bacterial cell-wall biosynthesis by binding and sequestering a cell-wall precursor: a d-alanine-containing peptide. A carrier-protein strategy was used to crystallize the complex of teicoplanin and its target peptide by fusing the cell-wall peptide to either MBP or ubiquitin via native chemical ligation and subsequently crystallizing the protein–peptide–antibiotic complex. The 2.05 Å resolution MBP–peptide–teicoplanin structure shows that teicoplanin recognizes its ligand through a combination of five hydrogen bonds and multiple van der Waals interactions. Comparison of this teicoplanin structure with that of unliganded teicoplanin reveals a flexibility in the antibiotic peptide backbone that has significant implications for ligand recognition. Diffraction experiments revealed an X-ray-induced dechlorination of the sixth amino acid of the antibiotic; it is shown that teicoplanin is significantly more radiation-sensitive than other similar antibiotics and that ligand binding increases radiosensitivity. Insights derived from this new teicoplanin structure may contribute to the development of next-generation antibacterials designed to overcome bacterial resistance

  16. Biosynthesis of 2-aminooctanoic acid and its use to terminally modify a lactoferricin B peptide derivative for improved antimicrobial activity.

    Science.gov (United States)

    Almahboub, Sarah A; Narancic, Tanja; Devocelle, Marc; Kenny, Shane T; Palmer-Brown, William; Murphy, Cormac; Nikodinovic-Runic, Jasmina; O'Connor, Kevin E

    2018-01-01

    Terminal modification of peptides is frequently used to improve their hydrophobicity. While N-terminal modification with fatty acids (lipidation) has been reported previously, C-terminal lipidation is limited as it requires the use of linkers. Here we report the use of a biocatalyst for the production of an unnatural fatty amino acid, (S)-2-aminooctanoic acid (2-AOA) with enantiomeric excess > 98% ee and the subsequent use of 2-AOA to modify and improve the activity of an antimicrobial peptide. A transaminase originating from Chromobacterium violaceum was employed with a conversion efficiency 52-80% depending on the ratio of amino group donor to acceptor. 2-AOA is a fatty acid with amino functionality, which allowed direct C- and N-terminal conjugation respectively to an antimicrobial peptide (AMP) derived from lactoferricin B. The antibacterial activity of the modified peptides was improved by up to 16-fold. Furthermore, minimal inhibitory concentrations (MIC) of C-terminally modified peptide were always lower than N-terminally conjugated peptides. The C-terminally modified peptide exhibited MIC values of 25 μg/ml for Escherichia coli, 50 μg/ml for Bacillus subtilis, 100 μg/ml for Salmonella typhimurium, 200 μg/ml for Pseudomonas aeruginosa and 400 μg/ml for Staphylococcus aureus. The C-terminally modified peptide was the only peptide tested that showed complete inhibition of growth of S. aureus.

  17. The role of GABAergic system on the inhibitory effect of ghrelin on food intake in neonatal chicks.

    Science.gov (United States)

    Jonaidi, H; Abbassi, L; Yaghoobi, M M; Kaiya, H; Denbow, D M; Kamali, Y; Shojaei, B

    2012-06-27

    Ghrelin is a gut-brain peptide that has a stimulatory effect on food intake in mammals. In contrast, this peptide decreases food intake in neonatal chicks when injected intracerebroventricularly (ICV). In mammals, neuropeptide Y (NPY) mediates the orexigenic effect of ghrelin whereas in chicks it appears that corticotrophin releasing factor (CRF) is partially involved in the inhibitory effect of ghrelin on food intake. Gamma aminobutyric acid (GABA) has a stimulatory effect on food intake in mammals and birds. In this study we investigated whether the anorectic effect of ghrelin is mediated by the GABAergic system. In Experiment 1, 3h-fasted chicks were given an ICV injection of chicken ghrelin and picrotoxin, a GABA(A) receptors antagonist. Picrotoxin decreased food intake compared to the control chicks indicating a stimulatory effect of GABA(A) receptors on food intake. However, picrotoxin did not alter the inhibitory effect of ghrelin on food intake. In Experiment 2, THIP hydrochloride, a GABA(A) receptor agonist, was used in place of picrotoxin. THIP hydrochloride appeared to partially attenuate the decrease in food intake induced by ghrelin at 30 min postinjection. In Experiment 3, the effect of ICV injection of chicken ghrelin on gene expression of glutamate decarboxylase (GAD)(1) and GAD(2), GABA synthesis enzymes in the brain stem including hypothalamus, was investigated. The ICV injection of chicken ghrelin significantly reduced GAD(2) gene expression. These findings suggest that ghrelin may decrease food intake in neonatal chicks by reducing GABA synthesis and thereby GABA release within brain feeding centers. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  18. High strength fused silica flexures manufactured by femtosecond laser

    Science.gov (United States)

    Bellouard, Yves; Said, Ali A.; Dugan, Mark; Bado, Philippe

    2009-02-01

    Flexures are mechanical elements used in micro- and precision-engineering to precisely guide the motion of micro-parts. They consist of slender bodies that deform elastically upon the application of a force. Although counter-intuitive at first, fused silica is an attractive material for flexure. Pending that the machining process does not introduce surface flaws that would lead to catastrophic failure, the material has a theoretically high ultimate tensile strength of several GPa. We report on high-aspect ratio fused silica flexures manufactured by femtosecond laser combined with chemical etching. Notch-hinges with thickness as small as twenty microns and aspect ratios comparable to aspect ratios obtained by Deep- Reactive-Ion-Etching (DRIE) were fabricated and tested under different loading conditions. Multiple fracture tests were performed for various loading conditions and the cracks morphologies were analyzed using Scanning Electron Microscopy. The manufactured elements show outstanding mechanical properties with flexural strengths largely exceeding those obtained with other technologies and materials. Fused silica flexures offer a mean to combine integrated optics with micro-mechanics in a single monolithic substrate. Waveguides and mechanical elements can be combined in a monolithic devices opening new opportunities for integrated opto-mechatronics devices.

  19. Comparing monolithic and fused core HPLC columns for fast chromatographic analysis of fat-soluble vitamins.

    Science.gov (United States)

    Kurdi, Said El; Muaileq, Dina Abu; Alhazmi, Hassan A; Bratty, Mohammed Al; Deeb, Sami El

    2017-06-27

    HPLC stationary phases of monolithic and fused core type can be used to achieve fast chromatographic separation as an alternative to UPLC. In this study, monolithic and fused core stationary phases are compared for fast separation of four fat-soluble vitamins. Three new methods on the first and second generation monolithic silica RP-18e columns and a fused core pentafluoro-phenyl propyl column were developed. Application of three fused core columns offered comparable separations of retinyl palmitate, DL-α-tocopheryl acetate, cholecalciferol and menadione in terms of elution speed and separation efficiency. Separation was achieved in approx. 5 min with good resolution (Rs > 5) and precision (RSD ≤ 0.6 %). Monolithic columns showed, however, a higher number of theoretical plates, better precision and lower column backpressure than the fused core column. The three developed methods were successfully applied to separate and quantitate fat-soluble vitamins in commercial products.

  20. Gastric inhibitory polypeptide does not inhibit gastric emptying in humans

    DEFF Research Database (Denmark)

    Meier, Juris J; Goetze, Oliver; Anstipp, Jens

    2004-01-01

    ) = 0.15, P = 0.15 for intact GIP; r(2) = 0.21, P = 0.086 for total GIP). We conclude that gastric emptying does not appear to be influenced by GIP. The secretion of GIP after meal ingestion is not suppressed by its exogenous administration. The lack of effect of GIP on gastric emptying underlines......The insulinotropic gut hormone gastric inhibitory polypeptide (GIP) has been demonstrated to inhibit gastric acid secretion and was proposed to possess "enterogastrone" activity. GIP effects on gastric emptying have not yet been studied. Fifteen healthy male volunteers (23.9 +/- 3.3 yr, body mass....... Gastric emptying was calculated from the (13)CO(2) exhalation rates in breath samples collected over 360 min. Venous blood was drawn in 30-min intervals for the determination of glucose, insulin, C-peptide, and GIP (total and intact). Statistical calculations were made by use of repeated-measures ANOVA...

  1. FUSE: a profit maximization approach for functional summarization of biological networks.

    Science.gov (United States)

    Seah, Boon-Siew; Bhowmick, Sourav S; Dewey, C Forbes; Yu, Hanry

    2012-03-21

    The availability of large-scale curated protein interaction datasets has given rise to the opportunity to investigate higher level organization and modularity within the protein interaction network (PPI) using graph theoretic analysis. Despite the recent progress, systems level analysis of PPIS remains a daunting task as it is challenging to make sense out of the deluge of high-dimensional interaction data. Specifically, techniques that automatically abstract and summarize PPIS at multiple resolutions to provide high level views of its functional landscape are still lacking. We present a novel data-driven and generic algorithm called FUSE (Functional Summary Generator) that generates functional maps of a PPI at different levels of organization, from broad process-process level interactions to in-depth complex-complex level interactions, through a pro t maximization approach that exploits Minimum Description Length (MDL) principle to maximize information gain of the summary graph while satisfying the level of detail constraint. We evaluate the performance of FUSE on several real-world PPIS. We also compare FUSE to state-of-the-art graph clustering methods with GO term enrichment by constructing the biological process landscape of the PPIS. Using AD network as our case study, we further demonstrate the ability of FUSE to quickly summarize the network and identify many different processes and complexes that regulate it. Finally, we study the higher-order connectivity of the human PPI. By simultaneously evaluating interaction and annotation data, FUSE abstracts higher-order interaction maps by reducing the details of the underlying PPI to form a functional summary graph of interconnected functional clusters. Our results demonstrate its effectiveness and superiority over state-of-the-art graph clustering methods with GO term enrichment.

  2. Dictionary-Based Image Denoising by Fused-Lasso Atom Selection

    Directory of Open Access Journals (Sweden)

    Ao Li

    2014-01-01

    Full Text Available We proposed an efficient image denoising scheme by fused lasso with dictionary learning. The scheme has two important contributions. The first one is that we learned the patch-based adaptive dictionary by principal component analysis (PCA with clustering the image into many subsets, which can better preserve the local geometric structure. The second one is that we coded the patches in each subset by fused lasso with the clustering learned dictionary and proposed an iterative Split Bregman to solve it rapidly. We present the capabilities with several experiments. The results show that the proposed scheme is competitive to some excellent denoising algorithms.

  3. YY-39, a tick anti-thrombosis peptide containing RGD domain.

    Science.gov (United States)

    Tang, Jing; Fang, Yaqun; Han, Yajun; Bai, Xuewei; Yan, Xiuwen; Zhang, Yun; Lai, Ren; Zhang, Zhiye

    2015-06-01

    Ticks are obligatory blood feeding ectoparasites, which continuously attach to their hosts for 1-2 weeks. There are many biologically active compounds in tick salivary glands interfering host haemostatic system and to successfully obtain blood meal. Several platelet aggregation inhibitors have been identified from ticks. A family of conserved peptides, which were identified from transcriptome analysis of many tick salivary glands, were found to contain unique primary structure including predicted mature peptides of 39-47 amino acid residues in length and a Pro/Glu(P/E)-Pro/His(P/H)-Lys-Gly-Asp(RGD) domain. Given their unique structure and RGD domain, they are considered a novel family of disintegrins that inhibit platelet aggregation. One of them (YY-39) was tested for its effects on platelets and thrombosis in vivo. YY-39 was found effectively to inhibit platelet aggregation induced by adenosine diphosphate (ADP), thrombin and thromboxane A2 (TXA2). Furthermore, YY-39 blocked platelet adhesion to soluble collagen and bound to purified GPIIb/IIIa in a dose-dependent manner. In in vivo experiments, YY-39 reduced thrombus weight effectively in a rat arteriovenous shunt model and inhibited thrombosis in a carrageenan-induced mouse tail thrombosis model. Combined with their prevalence in ticks and platelet inhibitory functions, this family of peptides might be conserved tick anti-haemostatic molecules. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Expression pattern of arenicins - the antimicrobial peptides of polychaete Arenicolamarina

    Directory of Open Access Journals (Sweden)

    Arina L. Maltseva

    2014-12-01

    Full Text Available Immune responses of invertebrate animals are mediated through innate mechanisms, among which production of antimicrobial peptides play an important role. Although evolutionary Polychaetes represent an interesting group closely related to a putative common ancestor of other coelomates, their immune mechanisms still remain scarcely investigated. Previously our group has identified arenicins - new antimicrobial peptides of the lugworm Arenicola marina, since then these peptides were thoroughly characterized in terms of their structure and inhibitory potential. In the present study we addressed the question of the physiological functions of arenicins in the lugworm body. Using molecular and immunocytochemical methods we demonstrated that arencins are expressed in the wide range of the lugworm tissues - coelomocytes, body wall, extravasal tissue and the gut. The expression of arenicins is constitutive and does not depend on stimulation of various infectious stimuli. Most intensively arenicins are produced by mature coelomocytes where they function as killing agents inside the phagolysosome. In the gut and the body wall epithelia arenicins are released from producing cells via secretion as they are found both inside the epithelial cells and in the contents of the cuticle. Collectively our study showed that arenicins are found in different body compartments responsible for providing a first line of defence against infections, which implies their important role as key components of both epithelial and systemic branches of host defence.

  5. Fluorescence-based characterization of genetically encoded peptides that fold in live cells: progress toward a generic hairpin scaffold

    Science.gov (United States)

    Cheng, Zihao; Campbell, Robert E.

    2007-02-01

    Binding proteins suitable for expression and high affinity molecular recognition in the cytoplasm or nucleus of live cells have numerous applications in the biological sciences. In an effort to add a new minimal motif to the growing repertoire of validated non-immunoglobulin binding proteins, we have undertaken the development of a generic protein scaffold based on a single β-hairpin that can fold efficiently in the cytoplasm. We have developed a method, based on the measurement of fluorescence resonance energy transfer (FRET) between a genetically fused cyan fluorescent protein (CFP) and yellow fluorescent protein (YFP), that allows the structural stability of recombinant β-hairpin peptides to be rapidly assessed both in vitro and in vivo. We have previously reported the validation of this method when applied to a 16mer tryptophan zipper β-hairpin. We now describe the use of this method to evaluate the potential of a designed 20mer β-hairpin peptide with a 3rd Trp/Trp cross-strand pair to function as a generic protein scaffold. Quantitative analysis of the FRET efficiency, resistance to proteolysis (assayed by loss of FRET), and circular dichroism spectra revealed that the 20mer peptide is significantly more tolerant of destabilizing mutations than the 16mer peptide. Furthermore, we experimentally demonstrate that the in vitro determined β-hairpin stabilities are well correlated with in vivo β-hairpin stabilities as determined by FRET measurements of colonies of live bacteria expressing the recombinant peptides flanked by CFP and YFP. Finally, we report on our progress to develop highly folded 24mer and 28mer β-hairpin peptides through the use of fluorescence-based library screening.

  6. Peptides, polypeptides and peptide-polymer hybrids as nucleic acid carriers.

    Science.gov (United States)

    Ahmed, Marya

    2017-10-24

    Cell penetrating peptides (CPPs), and protein transduction domains (PTDs) of viruses and other natural proteins serve as a template for the development of efficient peptide based gene delivery vectors. PTDs are sequences of acidic or basic amphipathic amino acids, with superior membrane trespassing efficacies. Gene delivery vectors derived from these natural, cationic and cationic amphipathic peptides, however, offer little flexibility in tailoring the physicochemical properties of single chain peptide based systems. Owing to significant advances in the field of peptide chemistry, synthetic mimics of natural peptides are often prepared and have been evaluated for their gene expression, as a function of amino acid functionalities, architecture and net cationic content of peptide chains. Moreover, chimeric single polypeptide chains are prepared by a combination of multiple small natural or synthetic peptides, which imparts distinct physiological properties to peptide based gene delivery therapeutics. In order to obtain multivalency and improve the gene delivery efficacies of low molecular weight cationic peptides, bioactive peptides are often incorporated into a polymeric architecture to obtain novel 'polymer-peptide hybrids' with improved gene delivery efficacies. Peptide modified polymers prepared by physical or chemical modifications exhibit enhanced endosomal escape, stimuli responsive degradation and targeting efficacies, as a function of physicochemical and biological activities of peptides attached onto a polymeric scaffold. The focus of this review is to provide comprehensive and step-wise progress in major natural and synthetic peptides, chimeric polypeptides, and peptide-polymer hybrids for nucleic acid delivery applications.

  7. Functional requirements for inhibitory signal transmission by the immunomodulatory receptor CD300a.

    Science.gov (United States)

    DeBell, Karen E; Simhadri, Venkateswara R; Mariano, John L; Borrego, Francisco

    2012-04-26

    Activation signals can be negatively regulated by cell surface receptors bearing immunoreceptor tyrosine-based inhibitory motifs (ITIMs). CD300a, an ITIM bearing type I transmembrane protein, is expressed on many hematopoietic cells, including subsets of lymphocytes. We have taken two approaches to further define the mechanism by which CD300a acts as an inhibitor of immune cell receptor signaling. First, we have expressed in Jurkat T cells a chimeric receptor consisting of the extracellular domains of killer-cell immunoglobulin-like receptor (KIR)2DL2 fused to the transmembrane and cytoplasmic segments of CD300a (KIR-CD300a) to explore surrogate ligand-stimulated inhibition of superantigen stimulated T cell receptor (TCR) mediated cell signaling. We found that intact CD300a ITIMs were essential for inhibition and that the tyrosine phosphorylation of these ITIMs required the src tyrosine kinase Lck. Tyrosine phosphorylation of the CD300a ITIMs created docking sites for both src homology 2 domain containing protein tyrosine phosphatase (SHP)-1 and SHP-2. Suppression of SHP-1 and SHP-2 expression in KIR-CD300a Jurkat T cells with siRNA and the use of DT40 chicken B cell lines expressing CD300a and deficient in several phosphatases revealed that SHP-1, but not SHP-2 or the src homology 2 domain containing inositol 5' phosphatase SHIP, was utilized by CD300a for its inhibitory activity. These studies provide new insights into the function of CD300a in tuning T and B cell responses.

  8. Overcurrent protection of transformers. Part 2: Traditional and new fusing philosophies for small and large transformers

    Energy Technology Data Exchange (ETDEWEB)

    Cook, C. J.; Niemira, J. K.

    2003-07-01

    New and traditional fusing philosophies for protecting transformers are discussed. This second in a two-part paper covers selection criteria for a transformer-primary fuse to protect the transformer consistent with industry-accepted through-fault protection curves. Also covered are the principles of coordination as they relate to the proper selection of the primary-side fuse and power fuses and the principles underlying the protection of load-side conductors and cables. The critical nature of secondary fault protection on small three-phase transformers used on industrial, commercial, and institutional power systems, as well as small-to-medium size three-phase power transformers used in utility substations is emphasized, in view of the long lead time and expense involved in replacing these transformers. In contrast, no special protection recommendations are made for small-kVA overhead distribution transformers, since they are not considered likely to experience secondary faults, and the rare faults that do occur will not likely be detected and cleared by the primary fuse. Also of importance is the fact that these transformers are inexpensive and readily available. Overall, large fuse rating, used in combination with a tank-mounted surge arrester is recommended, because it can provide better transformer protection than the smaller fuse ratings traditionally employed. 4 refs., 2 tabs., 4 figs.

  9. 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

  10. Crossed fused renal ectopia in a Persian cat

    Directory of Open Access Journals (Sweden)

    Sang-Hyuk Seo

    2017-03-01

    Full Text Available Case summary This report describes a rare case of crossed fused renal ectopia (CFRE in a cat. A mature intact male Persian cat presented with bloody nasal discharge and ascites. Diagnostic studies revealed an ectopic left kidney fused with an orthotopic right kidney and a concurrent feline infectious peritonitis (FIP infection. The FIP was responsible for clinical signs in this cat, while clinical signs associated with CFRE were not obvious. Despite receiving intensive treatment, the cat died. A post-mortem examination was not performed because the owners declined approval. Relevance and novel information To the best of our knowledge, this is the first report of L-shaped CFRE in a cat. In addition, this report describes the CT features of L-shaped CFRE in a cat.

  11. Diagnosis and staging of breast cancer by SPECT images fused with CT images

    International Nuclear Information System (INIS)

    Li Yanjing; Zhu Qiaomei

    2007-01-01

    Objective: To evaluate the TNM staging value of 99mTc-MIBI scintimammotraphy with SPECT-CT images fusing for the diagnosis of breast cancer. Methods: 10 patients with breast cancer underwent scintimammography with 99mTc-MIBI, and SPECT images were fused with CT images. Images were compared with final diagnosis confirmed by histopathology. Results: Of the 19 breast cancer patients, one case of invasive ductal carcinoma showed false-negative. Among 18 cases of positive lesions, axillary metastases were involved in 10, supraclavicular nodes were also defined in 3, para-sternum nodes were involved in 2, 2 were missed and 1 cases without metastatic node. The axillary lymph nodes were divided into three levels with respect to their position relative to the pectoralis minor muscle by fused images. Conclusion: 99mTc-MIBI scintimammotraphy combined with SPECT-CT images fusing is of some clinical value in TNM staging of breast cancer. (authors)

  12. Bulk damage and absorption in fused silica due to high-power laser applications

    Science.gov (United States)

    Nürnberg, F.; Kühn, B.; Langner, A.; Altwein, M.; Schötz, G.; Takke, R.; Thomas, S.; Vydra, J.

    2015-11-01

    Laser fusion projects are heading for IR optics with high broadband transmission, high shock and temperature resistance, long laser durability, and best purity. For this application, fused silica is an excellent choice. The energy density threshold on IR laser optics is mainly influenced by the purity and homogeneity of the fused silica. The absorption behavior regarding the hydroxyl content was studied for various synthetic fused silica grades. The main absorption influenced by OH vibrational excitation leads to different IR attenuations for OH-rich and low-OH fused silica. Industrial laser systems aim for the maximum energy extraction possible. Heraeus Quarzglas developed an Yb-doped fused silica fiber to support this growing market. But the performance of laser welding and cutting systems is fundamentally limited by beam quality and stability of focus. Since absorption in the optical components of optical systems has a detrimental effect on the laser focus shift, the beam energy loss and the resulting heating has to be minimized both in the bulk materials and at the coated surfaces. In collaboration with a laser research institute, an optical finisher and end users, photo thermal absorption measurements on coated samples of different fused silica grades were performed to investigate the influence of basic material properties on the absorption level. High purity, synthetic fused silica is as well the material of choice for optical components designed for DUV applications (wavelength range 160 nm - 260 nm). For higher light intensities, e.g. provided by Excimer lasers, UV photons may generate defect centers that effect the optical properties during usage, resulting in an aging of the optical components (UV radiation damage). Powerful Excimer lasers require optical materials that can withstand photon energy close to the band gap and the high intensity of the short pulse length. The UV transmission loss is restricted to the DUV wavelength range below 300 nm and

  13. Dendritic cells fused with different pancreatic carcinoma cells induce different T-cell responses

    Directory of Open Access Journals (Sweden)

    Andoh Y

    2013-01-01

    Full Text Available Yoshiaki Andoh,1,2 Naohiko Makino,2 Mitsunori Yamakawa11Department of Pathological Diagnostics, 2Department of Gastroenterology, Yamagata University School of Medicine, Yamagata, JapanBackground: It is unclear whether there are any differences in the induction of cytotoxic T lymphocytes (CTL and CD4+CD25high regulatory T-cells (Tregs among dendritic cells (DCs fused with different pancreatic carcinomas. The aim of this study was to compare the ability to induce cytotoxicity by human DCs fused with different human pancreatic carcinoma cell lines and to elucidate the causes of variable cytotoxicity among cell lines.Methods: Monocyte-derived DCs, which were generated from peripheral blood mononuclear cells (PBMCs, were fused with carcinoma cells such as Panc-1, KP-1NL, QGP-1, and KP-3L. The induction of CTL and Tregs, and cytokine profile of PBMCs stimulated by fused DCs were evaluated.Results: The cytotoxicity against tumor targets induced by PBMCs cocultured with DCs fused with QGP-1 (DC/QGP-1 was very low, even though PBMCs cocultured with DCs fused with other cell lines induced significant cytotoxicity against the respective tumor target. The factors causing this low cytotoxicity were subsequently investigated. DC/QGP-1 induced a significant expansion of Tregs in cocultured PBMCs compared with DC/KP-3L. The level of interleukin-10 secreted in the supernatants of PBMCs cocultured with DC/QGP-1 was increased significantly compared with that in DC/KP-3L. Downregulation of major histocompatibility complex class I expression and increased secretion of vascular endothelial growth factor were observed with QGP-1, as well as in the other cell lines.Conclusion: The present study demonstrated that the cytotoxicity induced by DCs fused with pancreatic cancer cell lines was different between each cell line, and that the reduced cytotoxicity of DC/QGP-1 might be related to the increased secretion of interleukin-10 and the extensive induction of Tregs

  14. Cocaine- and amphetamine-regulated transcript peptide in the nucleus accumbens shell inhibits cocaine-induced locomotor sensitization to transient over-expression of α-Ca2+ /calmodulin-dependent protein kinase II.

    Science.gov (United States)

    Xiong, Lixia; Meng, Qing; Sun, Xi; Lu, Xiangtong; Fu, Qiang; Peng, Qinghua; Yang, Jianhua; Oh, Ki-Wan; Hu, Zhenzhen

    2018-01-04

    Cocaine- and amphetamine-regulated transcript (CART) peptide is a widely distributed neurotransmitter that attenuates cocaine-induced locomotor activity when injected into the nucleus accumbens (NAc). Our previous work first confirmed that the inhibitory mechanism of the CART peptide on cocaine-induced locomotor activity is related to a reduction in cocaine-enhanced phosphorylated Ca 2+ /calmodulin-dependent protein kinaseIIα (pCaMKIIα) and the enhancement of cocaine-induced D3R function. This study investigated whether CART peptide inhibited cocaine-induced locomotor activity via inhibition of interactions between pCaMKIIα and the D3 dopamine receptor (D3R). We demonstrated that lentivirus-mediated gene transfer transiently increased pCaMKIIα expression, which peaked at 10 days after microinjection into the rat NAc shell, and induced a significant increase in Ca 2+ influx along with greater behavioral sensitivity in the open field test after intraperitoneal injections of cocaine (15 mg/kg). However, western blot analysis and coimmunoprecipitation demonstrated that CART peptide treatment in lentivirus-transfected CaMKIIα-over-expressing NAc rat tissues or cells prior to cocaine administration inhibited the cocaine-induced Ca 2+ influx and attenuated the cocaine-increased pCaMKIIα expression in lentivirus-transfected CaMKIIα-over-expressing cells. CART peptide decreased the cocaine-enhanced phosphorylated cAMP response element binding protein (pCREB) expression via inhibition of the pCaMKIIα-D3R interaction, which may account for the prolonged locomotor sensitization induced by repeated cocaine treatment in lentivirus-transfected CaMKIIα-over-expressing cells. These results provide strong evidence for the inhibitory modulation of CART peptide in cocaine-induced locomotor sensitization. © 2018 International Society for Neurochemistry.

  15. Comparing monolithic and fused core HPLC columns for fast chromatographic analysis of fat-soluble vitamins

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    Kurdi Said El

    2017-06-01

    Full Text Available HPLC stationary phases of monolithic and fused core type can be used to achieve fast chromatographic separation as an alternative to UPLC. In this study, monolithic and fused core stationary phases are compared for fast separation of four fat-soluble vitamins. Three new methods on the first and second generation monolithic silica RP-18e columns and a fused core pentafluoro-phenyl propyl column were developed. Application of three fused core columns offered comparable separations of retinyl palmitate, DL-α-tocopheryl acetate, cholecalciferol and menadione in terms of elution speed and separation efficiency. Separation was achieved in approx. 5 min with good resolution (Rs > 5 and precision (RSD ≤ 0.6 %. Monolithic columns showed, however, a higher number of theoretical plates, better precision and lower column backpressure than the fused core column. The three developed methods were successfully applied to separate and quantitate fat-soluble vitamins in commercial products.

  16. Thermodynamic perturbation theory for fused hard-sphere and hard-disk chain fluids

    International Nuclear Information System (INIS)

    Zhou, Y.; Hall, C.K.; Stell, G.

    1995-01-01

    We find that first-order thermodynamic perturbation theory (TPT1) which incorporates the reference monomer fluid used in the generalized Flory--AB (GF--AB) theory yields an equation of state for fused hard-sphere (FHS) chain fluids that has accuracy comparable to the GF--AB and GF--dimer--AC theories. The new TPT1 equation of state is significantly more accurate than other extensions of the TPT1 theory to FHS chain fluids. The TPT1 is also extended to two-dimensional fused hard-disk chain fluids. For the fused hard-disk dimer fluid, the extended TPT1 equation of state is found to be more accurate than the Boublik hard-disk dimer equation of state. copyright 1995 American Institute of Physics

  17. Generation of functional HLA-DR*1101 tetramers receptive for loading with pathogen or tumour derived synthetic peptides

    Directory of Open Access Journals (Sweden)

    Protti Maria

    2005-12-01

    Full Text Available Abstract Background MHC class I-peptide tetramers are currently utilised to characterize CD8+ T cell responses at single cell level. The generation and use of MHC class II tetramers to study antigen-specific CD4+ T cells appears less straightforward. Most MHC class II tetramers are produced with a homogeneously built-in peptide, reducing greatly their flexibility of use. We attempted the generation of "empty" functional HLA-DR*1101 tetramers, receptive for loading with synthetic peptides by incubation. No such reagent is in fact available for this HLA-DR allele, one of the most frequent in the Caucasian population. Results We compared soluble MHC class II-immunoglobulin fusion proteins (HLA-DR*1101-Ig with soluble MHC class II protein fused with an optimised Bir site for enzymatic biotynilation (HLA-DR*1101-Bir, both produced in insect cells. The molecules were multimerised by binding fluorochrome-protein A or fluorochrome-streptavidin, respectively. We find that HLA-DR*1101-Bir molecules are superior to the HLA-DR*1101-Ig ones both in biochemical and functional terms. HLA-DR*1101-Bir molecules can be pulsed with at least three different promiscuous peptide epitopes, derived from Tetanus Toxoid, influenza HA and the tumour associated antigen MAGE-3 respectively, to stain specific CD4+ T cells. Both staining temperature and activation state of CD4+ T cells are critical for the binding of peptide-pulsed HLA-DR*1101-Bir to the cognate TCR. Conclusion It is therefore possible to generate a soluble recombinant HLA-DR*1101 backbone that is receptive for loading with different peptides to stain specific CD4+ T cells. As shown for other HLA-DR alleles, we confirm that not all the strategies to produce soluble HLA-DR*1101 multimers are equivalent.

  18. FUSE: a profit maximization approach for functional summarization of biological networks

    Directory of Open Access Journals (Sweden)

    Seah Boon-Siew

    2012-03-01

    Full Text Available Abstract Background The availability of large-scale curated protein interaction datasets has given rise to the opportunity to investigate higher level organization and modularity within the protein interaction network (PPI using graph theoretic analysis. Despite the recent progress, systems level analysis of PPIS remains a daunting task as it is challenging to make sense out of the deluge of high-dimensional interaction data. Specifically, techniques that automatically abstract and summarize PPIS at multiple resolutions to provide high level views of its functional landscape are still lacking. We present a novel data-driven and generic algorithm called FUSE (Functional Summary Generator that generates functional maps of a PPI at different levels of organization, from broad process-process level interactions to in-depth complex-complex level interactions, through a pro t maximization approach that exploits Minimum Description Length (MDL principle to maximize information gain of the summary graph while satisfying the level of detail constraint. Results We evaluate the performance of FUSE on several real-world PPIS. We also compare FUSE to state-of-the-art graph clustering methods with GO term enrichment by constructing the biological process landscape of the PPIS. Using AD network as our case study, we further demonstrate the ability of FUSE to quickly summarize the network and identify many different processes and complexes that regulate it. Finally, we study the higher-order connectivity of the human PPI. Conclusion By simultaneously evaluating interaction and annotation data, FUSE abstracts higher-order interaction maps by reducing the details of the underlying PPI to form a functional summary graph of interconnected functional clusters. Our results demonstrate its effectiveness and superiority over state-of-the-art graph clustering methods with GO term enrichment.

  19. Evolutionary origin and divergence of GnIH and its homologous peptides.

    Science.gov (United States)

    Tsutsui, Kazuyoshi; Osugi, Tomohiro

    2009-03-01

    Probing undiscovered hypothalamic neuropeptides that play important roles in the regulation of pituitary function in vertebrates is essential for the progress of neuroendocrinology. In 2000, we discovered a novel hypothalamic dodecapeptide inhibiting gonadotropin release in quail and termed it gonadotropin-inhibitory hormone (GnIH). GnIH acts on the pituitary and gonadotropin-releasing hormone (GnRH) neurons in the hypothalamus via a novel G protein-coupled receptor for GnIH to inhibit gonadal development and maintenance by decreasing gonadotropin release and synthesis. Similar findings were observed in other avian species. Thus, GnIH is a key factor controlling avian reproduction. To give our findings a broader perspective, we also found GnIH homologous peptides in the hypothalamus of other vertebrates, such as mammals, reptiles, amphibians and teleosts. GnIH and its homologs share a common C-terminal LPXRFamide (X=L or Q) motif. A mammalian GnIH homolog also inhibited gonadotropin release in mammals like the GnIH action in birds. In contrast to higher vertebrates, hypophysiotropic activities of GnIH homologs were different in lower vertebrates. To clarify the evolutionary origin of GnIH and its homologs, we further sought to identify novel LPXRFamide peptides from the brain of sea lamprey and hagfish, two extant groups of the oldest lineage of vertebrates, Agnatha. In these agnathans, LPXRFamide peptide and its cDNA were identified only from the brain of hagfish. Based on these findings over the past decade, this paper summarizes the evolutionary origin and divergence of GnIH and its homologous peptides.

  20. 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.

  1. Active protein aggregates induced by terminally attached self-assembling peptide ELK16 in Escherichia coli

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    Zhou Bihong

    2011-02-01

    Full Text Available Abstract Background In recent years, it has been gradually realized that bacterial inclusion bodies (IBs could be biologically active. In particular, several proteins including green fluorescent protein, β-galactosidase, β-lactamase, alkaline phosphatase, D-amino acid oxidase, polyphosphate kinase 3, maltodextrin phosphorylase, and sialic acid aldolase have been successfully produced as active IBs when fused to an appropriate partner such as the foot-and-mouth disease virus capsid protein VP1, or the human β-amyloid peptide Aβ42(F19D. As active IBs may have many attractive advantages in enzyme production and industrial applications, it is of considerable interest to explore them further. Results In this paper, we report that an ionic self-assembling peptide ELK16 (LELELKLK2 was able to effectively induce the formation of cytoplasmic inclusion bodies in Escherichia coli (E. coli when attached to the carboxyl termini of four model proteins including lipase A, amadoriase II, β-xylosidase, and green fluorescent protein. These aggregates had a general appearance similar to the usually reported cytoplasmic inclusion bodies (IBs under transmission electron microscopy or fluorescence confocal microscopy. Except for lipase A-ELK16 fusion, the three other fusion protein aggregates retained comparable specific activities with the native counterparts. Conformational analyses by Fourier transform infrared spectroscopy revealed the existence of newly formed antiparallel beta-sheet structures in these ELK16 peptide-induced inclusion bodies, which is consistent with the reported assembly of the ELK16 peptide. Conclusions This has been the first report where a terminally attached self-assembling β peptide ELK16 can promote the formation of active inclusion bodies or active protein aggregates in E. coli. It has the potential to render E. coli and other recombinant hosts more efficient as microbial cell factories for protein production. Our observation might

  2. A hierarachical data structure representation for fusing multisensor information

    Energy Technology Data Exchange (ETDEWEB)

    Maren, A.J. [Tennessee Univ., Tullahoma, TN (United States). Space Inst.; Pap, R.M.; Harston, C.T. [Accurate Automation Corp., Chattanooga, TN (United States)

    1989-12-31

    A major problem with MultiSensor Information Fusion (MSIF) is establishing the level of processing at which information should be fused. Current methodologies, whether based on fusion at the data element, segment/feature, or symbolic levels, are each inadequate for robust MSIF. Data-element fusion has problems with coregistration. Attempts to fuse information using the features of segmented data relies on a Presumed similarity between the segmentation characteristics of each data stream. Symbolic-level fusion requires too much advance processing (including object identification) to be useful. MSIF systems need to operate in real-time, must perform fusion using a variety of sensor types, and should be effective across a wide range of operating conditions or deployment environments. We address this problem through developing a new representation level which facilitates matching and information fusion. The Hierarchical Data Structure (HDS) representation, created using a multilayer, cooperative/competitive neural network, meets this need. The HDS is an intermediate representation between the raw or smoothed data stream and symbolic interpretation of the data. it represents the structural organization of the data. Fused HDSs will incorporate information from multiple sensors. Their knowledge-rich structure aids top-down scene interpretation via both model matching and knowledge-based region interpretation.

  3. A hierarachical data structure representation for fusing multisensor information

    Energy Technology Data Exchange (ETDEWEB)

    Maren, A.J. (Tennessee Univ., Tullahoma, TN (United States). Space Inst.); Pap, R.M.; Harston, C.T. (Accurate Automation Corp., Chattanooga, TN (United States))

    1989-01-01

    A major problem with MultiSensor Information Fusion (MSIF) is establishing the level of processing at which information should be fused. Current methodologies, whether based on fusion at the data element, segment/feature, or symbolic levels, are each inadequate for robust MSIF. Data-element fusion has problems with coregistration. Attempts to fuse information using the features of segmented data relies on a Presumed similarity between the segmentation characteristics of each data stream. Symbolic-level fusion requires too much advance processing (including object identification) to be useful. MSIF systems need to operate in real-time, must perform fusion using a variety of sensor types, and should be effective across a wide range of operating conditions or deployment environments. We address this problem through developing a new representation level which facilitates matching and information fusion. The Hierarchical Data Structure (HDS) representation, created using a multilayer, cooperative/competitive neural network, meets this need. The HDS is an intermediate representation between the raw or smoothed data stream and symbolic interpretation of the data. it represents the structural organization of the data. Fused HDSs will incorporate information from multiple sensors. Their knowledge-rich structure aids top-down scene interpretation via both model matching and knowledge-based region interpretation.

  4. Immobilized sialyltransferase fused to a fungal biotin-binding protein: Production, properties, and applications.

    Science.gov (United States)

    Kajiwara, Hitomi; Tsunashima, Masako; Mine, Toshiki; Takakura, Yoshimitsu; Yamamoto, Takeshi

    2016-04-01

    A β-galactoside α2,6-sialyltransferase (ST) from the marine bacterium Photobacterium sp. JT-ISH-224 with a broad acceptor substrate specificity was fused to a fungal biotin-binding protein tamavidin 2 (TM2) to produce immobilized enzyme. Specifically, a gene for the fusion protein, in which ST from Photobacterium sp. JT-ISH-224 and TM2 were connected via a peptide linker (ST-L-TM2) was constructed and expressed in Escherichia coli. The ST-L-TM2 was produced in the soluble form with a yield of approximately 15,000 unit/300 ml of the E. coli culture. The ST-L-TM2 was partially purified and part of it was immobilized onto biotin-bearing magnetic microbeads. The immobilized ST-L-TM2 onto microbeads could be used at least seven consecutive reaction cycles with no observed decrease in enzymatic activity. In addition, the optimum pH and temperature of the immobilized enzyme were changed compared to those of a free form of the ST. Considering these results, it was strongly expected that the immobilized ST-L-TM2 was a promising tool for the production of various kind of sialoligosaccharides. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  5. Toxicity of inhaled 144Ce fused clay particles in beagle dogs. VII

    International Nuclear Information System (INIS)

    Hahn, F.F.; Boecker, B.B.; Hobbs, C.H.; Jones, R.K.; Mauderly, J.L.; McClellan, R.O.; Pickrell, J.A.

    1974-01-01

    The metabolism, dosimetry, and effects of inhaled 144 Ce in fused clay particles are being investigated in the Beagle dog to aid in assessing the biological consequences of release of 144 Ce in a relatively insoluble form such as might occur in certain types of nuclear accidents. The toxicity of inhaled 144 Ce fused clay is also of general interest since it is representative of intermediate-lived beta-emitting radionuclides. Two major studies with young adult dogs (12 to 14 months of age at exposure) are involved: (1) a metabolism and dosimetry study in which 24 dogs were serially sacrificed over an extended period of time, and (2) a longevity study with 2 series of dogs; Series I with 15 dogs exposed to aerosols of 144 Ce in fused clay particles to yield initial lung burdens of 11 to 210 μCi/kg body weight and 3 control dogs exposed to nonradioactive fused clay particles and Series II with 96 dogs exposed to aerosols of 144 Ce in fused clay particles to yield initial lung burdens of 0.0024 to 66 μCi/kg body weight and 12 control dogs exposed to nonradioactive fused clay particles. Twenty-eight dogs died or were euthanized at 143 to 2396 days after inhalation of 144 Ce. The prominent findings were radiation pneumonitis in 17 dogs that died or were euthanized at early time periods and neoplastic disease in 10 of the 11 dogs that died or were euthanized at 750 days or later; 5 with hemangiosarcoma of the lung, 1 with both a hemangiosarcoma and a fibrosarcoma of the lung, 1 with both a bronchiolo-alveolar carcinoma and a hemangiosarcoma of lung, 1 with a hemangiosarcoma of lung, bronchiolo-alveolar carcinoma, and a bronchiogenic adenocarcinoma, and 1 each with a hemangiosarcoma of the mediastinum and of the spleen. The cumulative radiation dose to the lung at time of death has ranged from 22,000 to 140,000 rads. Serial observations are continuing on the 83 survivors and 15 controls. (U.S.)

  6. Characterization of the functional domains of the natriuretic peptide receptor/guanylate cyclase by radiation inactivation

    International Nuclear Information System (INIS)

    Tremblay, J.; Huot, C.; Koch, C.; Potier, M.

    1991-01-01

    Radiation inactivation has been used to evaluate the molecular size of domains responsible for atrial natriuretic peptide (ANP)-binding and cyclase functions of the ANP receptor/guanylate cyclase. Two types of inactivation curves were observed for cyclase function in both adrenal cortex and aortic smooth muscle cells: (1) biphasic with enhanced guanylate cyclase activity after exposure to low radiation doses and (2) linear after preincubation of membrane proteins with 0.5 microM ANP or solubilization with Triton X-100. The existence of an inhibitory component was the simplest model that best explained the types of radiation curves obtained. Activation of guanylate cyclase by ANP or Triton X-100 could occur via the dissociation of this inhibitory component from the catalytic domain. On the other hand, the loss of ANP-binding activity was linear with increasing radiation exposures under basal, ANP treatment, and Triton X-100 solubilization conditions. Radiation inactivation sizes of about 30 kDa for cyclase function, 20 kDa for ANP-binding function, and 90 kDa for inhibitory function were calculated. These studies suggest that the ANP receptor/guanylate cyclase behaves as a multidomain protein. The results obtained by radiation inactivation of the various biological functions of this receptor are compatible with the hypothesis of an intramolecular inhibitory domain repressing the guanylate cyclase catalytic domain within its membrane environment

  7. Three-port beam splitter of a binary fused-silica grating.

    Science.gov (United States)

    Feng, Jijun; Zhou, Changhe; Wang, Bo; Zheng, Jiangjun; Jia, Wei; Cao, Hongchao; Lv, Peng

    2008-12-10

    A deep-etched polarization-independent binary fused-silica phase grating as a three-port beam splitter is designed and manufactured. The grating profile is optimized by use of the rigorous coupled-wave analysis around the 785 nm wavelength. The physical explanation of the grating is illustrated by the modal method. Simple analytical expressions of the diffraction efficiencies and modal guidelines for the three-port beam splitter grating design are given. Holographic recording technology and inductively coupled plasma etching are used to manufacture the fused-silica grating. Experimental results are in good agreement with the theoretical values.

  8. 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.

  9. Cavity Formation Modeling of Fiber Fuse in Single-Mode Optical Fibers

    Directory of Open Access Journals (Sweden)

    Yoshito Shuto

    2017-01-01

    Full Text Available The evolution of a fiber-fuse phenomenon in a single-mode optical fiber was studied theoretically. To clarify both the silica-glass densification and cavity formation, which have been observed in fiber fuse propagation, we investigated a nonlinear oscillation model using the Van Der Pol equation. This model was able to phenomenologically explain both the densification of the core material and the formation of periodic cavities in the core layer as a result of a relaxation oscillation.

  10. Antioxidant and Anti-Inflammatory Activities of Hydrolysates and Peptide Fractions Obtained by Enzymatic Hydrolysis of Selected Heat-Treated Edible Insects

    OpenAIRE

    Zielińska, Ewelina; Baraniak, Barbara; Karaś, Monika

    2017-01-01

    This study investigated the effect of heat treatment of edible insects on antioxidant and anti-inflammatory activities of peptides obtained by in vitro gastrointestinal digestion and absorption process thereof. The antioxidant potential of edible insect hydrolysates was determined as free radical-scavenging activity, ion chelating activity, and reducing power, whereas the anti-inflammatory activity was expressed as lipoxygenase and cyclooxygenase-2 inhibitory activity. The highest antiradical...

  11. Supraspinal inhibitory effects of chimeric peptide MCRT on gastrointestinal motility in mice.

    Science.gov (United States)

    He, Chunbo; Li, Hailan; Zhang, Jing; Kang, Yanping; Jia, Fang; Dong, Shouliang; Zhou, Lanxia

    2017-09-01

    Chimeric peptide MCRT, based on morphiceptin and PFRTic-NH 2 , was a bifunctional ligand of μ- and δ-opioid receptors (MOR-DOR) and produced potent analgesia in tail-withdrawal test. The study focused on the supraspinal effects of morphiceptin, PFRTic-NH 2 and MCRT on gastrointestinal motility. Moreover, opioid receptor antagonists, naloxone (non-selective), cyprodime (MOR selective) and naltrindole (DOR selective) were utilized to explore the mechanisms. Intracerebroventricular administration was achieved via the implanted cannula. Gastric emptying and intestinal transit were measured to evaluate gastrointestinal motility. (1) At supraspinal level, morphiceptin, PFRTic-NH 2 and MCRT significantly decreased gastric emptying and intestinal transit; (2) MCRT at 1 nmol/mouse, far higher than its analgesic dose (ED 50  = 29.8 pmol/mouse), failed to regulate the gastrointestinal motility; (3) MCRT-induced gastrointestinal dysfunction could be completely blocked by naloxone and naltrindole, but not affected by cyprodime. (1) Morphiceptin and PFRTic-NH 2 played important roles in the regulation of gastrointestinal motility; (2) MCRT possessed higher bioactivity of pain relief than gastrointestinal regulation, suggesting its promising analgesic property; (3) MCRT-induced motility disorders were sensitive to DOR but not to MOR blockade, indicating the pain-relieving specificity of speculated MOR subtype or splice variant or MOR-DOR heterodimer. © 2017 Royal Pharmaceutical Society.

  12. Identification of novel inhibitors of Pseudomonas aeruginosa MurC enzyme derived from phage-displayed peptide libraries.

    Science.gov (United States)

    El Zoeiby, Ahmed; Sanschagrin, François; Darveau, André; Brisson, Jean-Robert; Levesque, Roger C

    2003-03-01

    The machinery of peptidoglycan biosynthesis is an ideal site at which to look for novel antimicrobial targets. Phage display was used to develop novel peptide inhibitors for MurC, an essential enzyme involved in the early steps of biosynthesis of peptidoglycan monomer. We cloned and overexpressed the murA, -B and -C genes from Pseudomonas aeruginosa in the pET expression vector, adding a His-tag to their C termini. The three proteins were overproduced in Escherichia coli and purified to homogeneity in milligram quantities. MurA and -B were combinatorially used to synthesize the MurC substrate UDP-N-acetylmuramate, the identity of which was confirmed by mass spectrometry and nuclear magnetic resonance analysis. Two phage-display libraries were screened against MurC in order to identify peptide ligands to the enzyme. Three rounds of biopanning were carried out, successively increasing elution specificity from round 1 to 3. The third round was accomplished with both non-specific elution and competitive elution with each of the three MurC substrates, UDP-N-acetylmuramic acid (UNAM), ATP and L-alanine. The DNA of 10 phage, selected randomly from each group, was extracted and sequenced, and consensus peptide sequences were elucidated. Peptides were synthesized and tested for inhibition of the MurC-catalysed reaction, and two peptides were shown to be inhibitors of MurC activity with IC(50)s of 1.5 and 0.9 mM, respectively. The powerful selection technique of phage display allowed us to identify two peptide inhibitors of the essential bacterial enzyme MurC. The peptide sequences represent the basis for the synthesis of inhibitory peptidomimetic molecules.

  13. Fusing Intelligence With Law Enforcement Information: An Analytic Imperative

    National Research Council Canada - National Science Library

    Thornlow, Christopher C

    2005-01-01

    ... and Law Enforcement Communities to fuse and analyze foreign threat intelligence with domestic law enforcement information in a timely fashion to provide adequate indications and warning of such an...

  14. New developments in fused deposition modeling of ceramics

    DEFF Research Database (Denmark)

    Bellini, Anna; Shor, L.; Guceri, S.I.

    2005-01-01

    Purpose - To shift from rapid prototyping (RP) to agile fabrication by broadening the material selection, e.g. using ceramics, hence improving the properties (e.g. mechanical properties) of fused deposition modeling (FDM) products. Design/methodology/approach - This paper presents the development...

  15. Galectin-1-asialofetuin interaction is inhibited by peptides containing the tyr-xxx-tyr motif acting on the glycoprotein.

    Science.gov (United States)

    Wéber, Edit; Hetényi, Anasztázia; Váczi, Balázs; Szolnoki, Eva; Fajka-Boja, Roberta; Tubak, Vilmos; Monostori, Eva; Martinek, Tamás A

    2010-01-25

    Galectin-1 (Gal-1), a ubiquitous beta-galactoside-binding protein expressed by various normal and pathological tissues, has been implicated in cancer and autoimmune/inflammatory diseases in consequence of its regulatory role in adhesion, cell viability, proliferation, and angiogenesis. The functions of Gal-1 depend on its affinity for beta-galactoside-containing glycoconjugates; accordingly, the inhibition of sugar binding blocks its functions, hence promising potential therapeutic tools. The Tyr-Xxx-Tyr peptide motifs have been reported to be glycomimetic sequences, mainly on the basis of their inhibitory effect on the Gal-1-asialofetuin (ASF) interaction. However, the results regarding the efficacy of the Tyr-Xxx-Tyr motif as a glycomimetic inhibitor are still controversial. The present STD and trNOE NMR experiments reveal that the Tyr-Xxx-Tyr peptides studied do not bind to Gal-1, whereas their binding to ASF is clearly detected. (15)N,(1)H HSQC titrations with (15)N-labeled Gal-1 confirm the absence of any peptide-Gal-1 interaction. These data indicate that the Tyr-Xxx-Tyr peptides tested in this work are not glycomimetics as they interact with ASF via an unrevealed molecular linkage.

  16. Inhibitory effect of mTOR activator MHY1485 on autophagy: suppression of lysosomal fusion.

    Directory of Open Access Journals (Sweden)

    Yeon Ja Choi

    Full Text Available Autophagy is a major degradative process responsible for the disposal of cytoplasmic proteins and dysfunctional organelles via the lysosomal pathway. During the autophagic process, cells form double-membraned vesicles called autophagosomes that sequester disposable materials in the cytoplasm and finally fuse with lysosomes. In the present study, we investigated the inhibition of autophagy by a synthesized compound, MHY1485, in a culture system by using Ac2F rat hepatocytes. Autophagic flux was measured to evaluate the autophagic activity. Autophagosomes were visualized in Ac2F cells transfected with AdGFP-LC3 by live-cell confocal microscopy. In addition, activity of mTOR, a major regulatory protein of autophagy, was assessed by western blot and docking simulation using AutoDock 4.2. In the result, treatment with MHY1485 suppressed the basal autophagic flux, and this inhibitory effect was clearly confirmed in cells under starvation, a strong physiological inducer of autophagy. The levels of p62 and beclin-1 did not show significant change after treatment with MHY1485. Decreased co-localization of autophagosomes and lysosomes in confocal microscopic images revealed the inhibitory effect of MHY1485 on lysosomal fusion during starvation-induced autophagy. These effects of MHY1485 led to the accumulation of LC3II and enlargement of the autophagosomes in a dose- and time-dependent manner. Furthermore, MHY1485 induced mTOR activation and correspondingly showed a higher docking score than PP242, a well-known ATP-competitive mTOR inhibitor, in docking simulation. In conclusion, MHY1485 has an inhibitory effect on the autophagic process by inhibition of fusion between autophagosomes and lysosomes leading to the accumulation of LC3II protein and enlarged autophagosomes. MHY1485 also induces mTOR activity, providing a possibility for another regulatory mechanism of autophagy by the MHY compound. The significance of this study is the finding of a novel

  17. A comparative clinical, pathological, biochemical and genetic study of fused in sarcoma proteinopathies

    DEFF Research Database (Denmark)

    Lashley, Tammaryn; Rohrer, Jonathan D; Bandopadhyay, Rina

    2011-01-01

    Neuronal intermediate filament inclusion disease and atypical frontotemporal lobar degeneration are rare diseases characterized by ubiquitin-positive inclusions lacking transactive response DNA-binding protein-43 and tau. Recently, mutations in the fused in sarcoma gene have been shown to cause...... findings, as well as genetic and biochemical data in 14 fused in sarcoma proteinopathy cases. In this cohort, the age of onset was variable but included cases of young-onset disease. Patients with atypical frontotemporal lobar degeneration with ubiquitinated inclusions all presented with behavioural...... familial amyotrophic lateral sclerosis and fused in sarcoma-positive neuronal inclusions have subsequently been demonstrated in neuronal intermediate filament inclusion disease and atypical frontotemporal lobar degeneration with ubiquitinated inclusions. Here we provide clinical, imaging, morphological...

  18. Peptide domains involved in the localization of the porcine reproductive and respiratory syndrome virus nucleocapsid protein to the nucleolus

    International Nuclear Information System (INIS)

    Rowland, Raymond R.R.; Schneider, Paula; Fang Ying; Wootton, Sarah; Yoo, Dongwan; Benfield, David A.

    2003-01-01

    The nucleocapsid (N) protein of porcine reproductive and respiratory syndrome virus (PRRSV) is the principal component of the viral nucleocapsid and localizes to the nucleolus. Peptide sequence analysis of the N protein of several North American isolates identified two potential nuclear localization signal (NLS) sequences located at amino acids 10-13 and 41-42, which were labeled NLS-1 and NLS-2, respectively. Peptides containing NLS-1 or NLS-2 were sufficient to accumulate enhanced green fluorescent protein (EGFP) in the nucleus. The inactivation of NLS-1 by site-directed mutagenesis or the deletion of the first 14 amino acids did not affect N protein localization to the nucleolus. The substitution of key lysine residues with uncharged amino acids in NLS-2 blocked nuclear/nucleolar localization. Site-directed mutagenesis within NLS-2 identified the sequence, KKNKK, as forming the core localization domain within NLS-2. Using an in vitro pull-down assay, the N protein was able to bind importin-α, importin-β nuclear transport proteins. The localization pattern of N-EGFP fusion peptides represented by a series of deletions from the C- and N-terminal ends of the N protein identified a region covering amino acids 41-72, which contained a nucleolar localization signal (NoLS) sequence. The 41-72 N peptide when fused to EGFP mimicked the nucleolar-cytoplasmic distribution of native N. These results identify a single NLS involved in the transport of N from the cytoplasm and into nucleus. An additional peptide sequence, overlapping NLS-2, is involved in the further targeting of N to the nucleolus

  19. Benign versus malignant osseous lesions in spine: differentiation by means of bone SPECT/CT fused image

    International Nuclear Information System (INIS)

    Yao Zhiming; Qu Wanying

    2004-01-01

    This study compared the efficiency of SPECT-CT fused image with planar bone scan, bone SPECT and CT in differentiating malignant from benign lesions and detecting metastases to the spine. Methods. Total 144 patients with spinal lesions underwent planar bone scan (WB), single photon tomography (SPECT), CT and SPECT-CT fused image by a SPECT/CT system. The malignant or benign nature of lesions was proved by radiological Methods, histological findings, 6-24 month follow-up, or all of these. The diagnostic results was divided into 4 types, i.e., normal, benign, doubtful malignant and malignant. Results. There were 137 malignant and 252 benign lesions in 144 patients, respectively. The percentages of doubtful malignant diagnosed by WB, SPECT, CT and fused image are 22.6%, 5.1%, 9.5% and 0%, respectively, p < 0.01-0.001, except for the comparison between the percentages of SPECT and CT. Sensitivities in detection of malignant lesions by WB, SPECT, CT and fused image are 75.2%, 94.2%, 96.6% and 99.3%, respectively, P < 0.001, excepting for the comparisons between those of SPECT and CT, and between those of CT and fused image. The sensitivities m detection of benign lesions by WB, SPECT, CT and fused image are, 56.7%, 86.5%, 90.1% and 96.8%, respectively, P < 0.005 - 0.001, excepting for the comparison between those of SPECT and CT. The specificities in detection of maliganant lesions by WB, SPECT, CT and fused image are 70.6%, 88.9%, 97.2% and 97.6%, respectively, P < 0.001, excepting for the comparison between those of CT and fused image. Conclusion. Bone SPECT-CT fused image has highest diagnostic and differentiating diagnostic values in detection of spinal abnormalities over the planar bone scanning and SPECT. The CT by present SPECT/CT system can complement planar bone scanning and SPECT and is clinically valuable in detection of spinal abnormalities. (authors)

  20. A system for the non-destructive detection of faults in safety fuses using radioisotopes

    International Nuclear Information System (INIS)

    Goncalves, D.

    1980-01-01

    Design of an equipment for on line detection of faults in the safety fuses for conventional explosives employing transmission of #betta#-radiation is reported. The faults are detected by an ion-chamber based on the variation of the intensity of the beta particles transmitted through the fuse during its passage across the collimated beam. Strontium-90 encapsulated in stainless steel or aluminum is used as the #betta#-source. An electrical signal corresponding the fault is obtained by subtraction of an external current, that is equivalent to the output of the ion-chamber in the presence of faultless fuse. (Author) [pt

  1. HVI Ballistic Limit Charaterization of Fused Silica Thermal Pane

    Science.gov (United States)

    Bohl, William E.; Miller, Joshua E.; Christiansen, Eric L.; Deighton, Kevin.; Davis, Bruce

    2015-01-01

    The Orion spacecraft's windows are exposed to the micrometeroid and orbital debris (MMOD) space environments while in space as well as the Earth entry environment at the mission's conclusion. The need for a low-mass spacecraft window design drives the need to reduce conservatism when assessing the design for loss of crew due to MMOD impact and subsequent Earth entry. Therefore, work is underway at NASA and Lockheed Martin to improve characterization of the complete penetration ballistic limit of an outer fused silica thermal pane. Hypervelocity impact tests of the window configuration at up to 10 km/s and hydrocode modeling have been performed with a variety of projectile materials to enable refinement of the fused silica ballistic limit equation.

  2. Effects of Lys to Glu mutations in GsMTx4 on membrane binding, peptide orientation, and self-association propensity, as analyzed by molecular dynamics simulations.

    Science.gov (United States)

    Nishizawa, Kazuhisa; Nishizawa, Manami; Gnanasambandam, Radhakrishnan; Sachs, Frederick; Sukharev, Sergei I; Suchyna, Thomas M

    2015-11-01

    GsMTx4, a gating modifier peptide acting on cationic mechanosensitive channels, has a positive charge (+5e) due to six Lys residues. The peptide does not have a stereospecific binding site on the channel but acts from the boundary lipids within a Debye length of the pore probably by changing local stress. To gain insight into how these Lys residues interact with membranes, we performed molecular dynamics simulations of Lys to Glu mutants in parallel with our experimental work. In silico, K15E had higher affinity for 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine bilayers than wild-type (WT) peptide or any other mutant tested, and showed deeper penetration than WT, a finding consistent with the experimental data. Experimentally, the inhibitory activities of K15E and K25E were most compromised, whereas K8E and K28E inhibitory activities remained similar to WT peptide. Binding of WT in an interfacial mode did not influence membrane thickness. With interfacial binding, the direction of the dipole moments of K15E and K25E was predicted to differ from WT, whereas those of K8E and K28E oriented similarly to that of WT. These results support a model in which binding of GsMTx4 to the membrane acts like an immersible wedge that serves as a membrane expansion buffer reducing local stress and thus inhibiting channel activity. In simulations, membrane-bound WT attracted other WT peptides to form aggregates. This may account for the positive cooperativity observed in the ion channel experiments. The Lys residues seem to fine-tune the depth of membrane binding, the tilt angle, and the dipole moments. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. [XPS analysis of beads formed by fuse breaking of electric copper wire].

    Science.gov (United States)

    Wu, Ying; Meng, Qing-Shan; Wang, Xin-Ming; Gao, Wei; Di, Man

    2010-05-01

    The in-depth composition of beads formed by fuse breaking of the electric copper wire in different circumstances was studied by XPS with Ar+ ion sputtering. In addition, the measured Auger spectra and the calculated Auger parameters were compared for differentiation of the substances of Cu and Cu2O. Corresponding to the sputtering depth, the molten product on a bead induced directly by fuse breaking of the copper wire without cover may be distinguished as three portions: surface layer with a drastic decrease in carbon content; intermediate layer with a gentle change in oxygen content and gradually diminished carbon peak, and consisting of Cu2O; transition layer without Cu2O and with a rapid decrease in oxygen content. While the molten product on a bead formed by fuse breaking of the copper wire after its insulating cover had been burned out may be distinguished as two portions: surface layer with carbon content decreasing quickly; subsurface layer without Cu2O and with carbon and oxygen content decreasing gradually. Thus, it can be seen that there was an obvious interface between the layered surface product and the substrate for the first type of bead, while as to the second type of bead there was no interface. As a result, the presence of Cu2O and the quantitative results can be used to identify the molten product on a bead induced directly by fuse breaking of the copper wire without cover and the molten product on a bead formed by fuse breaking of the cupper wire after its insulating cover had been burned out, as a complementary technique for the judgments of fire cause.

  4. SimFuse: A Novel Fusion Simulator for RNA Sequencing (RNA-Seq Data

    Directory of Open Access Journals (Sweden)

    Yuxiang Tan

    2015-01-01

    Full Text Available The performance evaluation of fusion detection algorithms from high-throughput sequencing data crucially relies on the availability of data with known positive and negative cases of gene rearrangements. The use of simulated data circumvents some shortcomings of real data by generation of an unlimited number of true and false positive events, and the consequent robust estimation of accuracy measures, such as precision and recall. Although a few simulated fusion datasets from RNA Sequencing (RNA-Seq are available, they are of limited sample size. This makes it difficult to systematically evaluate the performance of RNA-Seq based fusion-detection algorithms. Here, we present SimFuse to address this problem. SimFuse utilizes real sequencing data as the fusions’ background to closely approximate the distribution of reads from a real sequencing library and uses a reference genome as the template from which to simulate fusions’ supporting reads. To assess the supporting read-specific performance, SimFuse generates multiple datasets with various numbers of fusion supporting reads. Compared to an extant simulated dataset, SimFuse gives users control over the supporting read features and the sample size of the simulated library, based on which the performance metrics needed for the validation and comparison of alternative fusion-detection algorithms can be rigorously estimated.

  5. Electromigration driven failures on miniature silver fuses at the Large Hadron Collider

    CERN Document Server

    Trikoupis, Nikolaos; Perez Fontenla, Ana Teresa

    2017-01-01

    Spurious faults were observed on the miniature silver fuses of electronic cards used for the cryogenics instrumentation in the LHC (Large Hadron Collider) accelerator at CERN. By applying analytical tools and techniques such as Scanning Electron Microscopy, spectrometry and Weibull reliability calculations and by the knowledge of operating temperatures and operational time of each unit, the origin of the problem has now been understood and can be attributed to electromigration. The selected fuse was operated at moderate temperature and load conditions and was considered as a “lifetime” component. However, it turned out to have a smaller than expected MTTF with failures following a Weibull distribution of $\\beta = 3.91$ and $\\eta = 2323$. The literature describes extensively the effects of electromigration, but there are only limited references referring to the impact of this phenomenon on miniature silver fuses for electronic circuits.

  6. A homeostatic sleep-stabilizing pathway in Drosophila composed of the sex peptide receptor and its ligand, the myoinhibitory peptide.

    Directory of Open Access Journals (Sweden)

    Yangkyun Oh

    2014-10-01

    Full Text Available Sleep, a reversible quiescent state found in both invertebrate and vertebrate animals, disconnects animals from their environment and is highly regulated for coordination with wakeful activities, such as reproduction. The fruit fly, Drosophila melanogaster, has proven to be a valuable model for studying the regulation of sleep by circadian clock and homeostatic mechanisms. Here, we demonstrate that the sex peptide receptor (SPR of Drosophila, known for its role in female reproduction, is also important in stabilizing sleep in both males and females. Mutants lacking either the SPR or its central ligand, myoinhibitory peptide (MIP, fall asleep normally, but have difficulty in maintaining a sleep-like state. Our analyses have mapped the SPR sleep function to pigment dispersing factor (pdf neurons, an arousal center in the insect brain. MIP downregulates intracellular cAMP levels in pdf neurons through the SPR. MIP is released centrally before and during night-time sleep, when the sleep drive is elevated. Sleep deprivation during the night facilitates MIP secretion from specific brain neurons innervating pdf neurons. Moreover, flies lacking either SPR or MIP cannot recover sleep after the night-time sleep deprivation. These results delineate a central neuropeptide circuit that stabilizes the sleep state by feeding a slow-acting inhibitory input into the arousal system and plays an important role in sleep homeostasis.

  7. Fusion algebra and fusing matrices

    International Nuclear Information System (INIS)

    Gao Yihong; Li Miao; Yu Ming.

    1989-09-01

    We show that the Wilson line operators in topological field theories form a fusion algebra. In general, the fusion algebra is a relation among the fusing (F) matrices. In the case of the SU(2) WZW model, some special F matrix elements are found in this way, and the remaining F matrix elements are then determined up to a sign. In addition, the S(j) modular transformation of the one point blocks on the torus is worked out. Our results are found to agree with those obtained from the quantum group method. (author). 24 refs

  8. A vaccine strategy with multiple prostatic acid phosphatase-fused cytokines for prostate cancer treatment.

    Science.gov (United States)

    Fujio, Kei; Watanabe, Masami; Ueki, Hideo; Li, Shun-Ai; Kinoshita, Rie; Ochiai, Kazuhiko; Futami, Junichiro; Watanabe, Toyohiko; Nasu, Yasutomo; Kumon, Hiromi

    2015-04-01

    Immunotherapy is one of the attractive treatment strategies for advanced prostate cancer. The US Food and Drug Administration (FDA) previously approved the therapeutic vaccine, sipuleucel-T, which is composed of autologous antigen-presenting cells cultured with a fusion protein [prostatic acid phosphatase (PAP) and granulocyte-macrophage colony-stimulating factor (GMCSF)]. Although sipuleucel-T has been shown to prolong the median survival of patients for 4.1 months, more robust therapeutic effects may be expected by modifying the vaccination protocol. In the present study, we aimed to develop and validate a novel vaccination strategy using multiple PAP-fused cytokines for prostate cancer treatment. Using a super gene expression (SGE) system that we previously established to amplify the production of a recombinant protein, significant amounts of PAP-fused cytokines [human GMCSF, interleukin-2 (IL2), IL4, IL7 and mouse GMCSF and IL4] were obtained. We examined the activity of the fusion proteins in vitro to validate their cytokine functions. A significant upregulation of dendritic cell differentiation from monocytes was achieved by PAP-GMCSF when used with the other PAP-fused cytokines. The PAP-fused human IL2 significantly increased the proliferation of lymphocytes, as determined by flow cytometry. We also investigated the in vivo therapeutic effects of multiple PAP-fused cytokines in a mouse prostate cancer model bearing prostate-specific antigen (PSA)- and PAP-expressing tumors. The simultaneous intraperitoneal administration of PAP-GMCSF, -IL2, -IL4 and -IL7 significantly prevented tumor induction and inhibited the tumor growth in the PAP-expressing tumors, yet not in the PSA-expressing tumors. The in vivo therapeutic effects with the multiple PAP-fused cytokines were superior to the effects of PAP-GMCSF alone. We thus demonstrated the advantages of the combined use of multiple PAP-fused cytokines including PAP-GMCSF, and propose a promising prostatic

  9. The intrinsic antimicrobial activity of citric acid-coated manganese ferrite nanoparticles is enhanced after conjugation with the antifungal peptide Cm-p5

    Science.gov (United States)

    Lopez-Abarrategui, Carlos; Figueroa-Espi, Viviana; Lugo-Alvarez, Maria B; Pereira, Caroline D; Garay, Hilda; Barbosa, João ARG; Falcão, Rosana; Jiménez-Hernández, Linnavel; Estévez-Hernández, Osvaldo; Reguera, Edilso; Franco, Octavio L; Dias, Simoni C; Otero-Gonzalez, Anselmo J

    2016-01-01

    Diseases caused by bacterial and fungal pathogens are among the major health problems in the world. Newer antimicrobial therapies based on novel molecules urgently need to be developed, and this includes the antimicrobial peptides. In spite of the potential of antimicrobial peptides, very few of them were able to be successfully developed into therapeutics. The major problems they present are molecule stability, toxicity in host cells, and production costs. A novel strategy to overcome these obstacles is conjugation to nanomaterial preparations. The antimicrobial activity of different types of nanoparticles has been previously demonstrated. Specifically, magnetic nanoparticles have been widely studied in biomedicine due to their physicochemical properties. The citric acid-modified manganese ferrite nanoparticles used in this study were characterized by high-resolution transmission electron microscopy, which confirmed the formation of nanocrystals of approximately 5 nm diameter. These nanoparticles were able to inhibit Candida albicans growth in vitro. The minimal inhibitory concentration was 250 µg/mL. However, the nanoparticles were not capable of inhibiting Gram-negative bacteria (Escherichia coli) or Gram-positive bacteria (Staphylococcus aureus). Finally, an antifungal peptide (Cm-p5) from the sea animal Cenchritis muricatus (Gastropoda: Littorinidae) was conjugated to the modified manganese ferrite nanoparticles. The antifungal activity of the conjugated nanoparticles was higher than their bulk counterparts, showing a minimal inhibitory concentration of 100 µg/mL. This conjugate proved to be nontoxic to a macrophage cell line at concentrations that showed antimicrobial activity. PMID:27563243

  10. 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.

  11. Fiber fuse light-induced continuous breakdown of silica glass optical fiber

    CERN Document Server

    Todoroki, Shin-ichi

    2014-01-01

    This book describes the fiber fuse phenomenon that causes a serious problem for the present optical communication systems. High-power light often brings about catastrophic damage to optical devices. Silica glass optical fibers with ultralow transmission loss are not the exception. A fiber fuse appears in a heated region of the fiber cable delivering a few watts of light and runs toward the light source destroying its core region. Understanding this phenomenon is a necessary first step in the development of future optical communication systems. This book provides supplementary videos and photog

  12. High-voltage safety fuses for the transition-radiation tracking detector in the ATLAS experiment

    NARCIS (Netherlands)

    Voronov, SA; Voronov, YA; Onishchenko, EM; Simakov, AB; Sosnovtsev, VV; Suchkov, SI; Sugrobova, TA

    2004-01-01

    A safety fuse has been designed for the electrical protection of gas-filled detectors in the ATLAS experiment at CERN (Geneva, Switzerland). The fuse is a polished lithium niobate plate with a titanium strip of 91-kOmega resistance deposited by the photolithographic technique. The forced blow-out

  13. Alanine scan of the peptide antibiotic feglymycin: assessment of amino acid side chains contributing to antimicrobial activity.

    Science.gov (United States)

    Hänchen, Anne; Rausch, Saskia; Landmann, Benjamin; Toti, Luigi; Nusser, Antje; Süssmuth, Roderich D

    2013-03-18

    The antibiotic feglymycin is a linear 13-mer peptide synthesized by the bacterium Streptomyces sp. DSM 11171. It mainly consists of the nonproteinogenic amino acids 4-hydroxyphenylglycine and 3,5-dihydroxyphenylglycine. An alanine scan of feglymycin was performed by solution-phase peptide synthesis in order to assess the significance of individual amino acid side chains for biological activity. Hence, 13 peptides were synthesized from di- and tripeptide building blocks, and subsequently tested for antibacterial activity against Staphylococcus aureus strains. Furthermore we tested the inhibition of peptidoglycan biosynthesis enzymes MurA and MurC, which are inhibited by feglymycin. Whereas the antibacterial activity is significantly based on the three amino acids D-Hpg1, L-Hpg5, and L-Phe12, the inhibitory activity against MurA and MurC depends mainly on L-Asp13. The difference in the position dependence for antibacterial activity and enzyme inhibition suggests multiple molecular targets in the modes of action of feglymycin. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Helicopter Aircrew Training Using Fused Reality

    Science.gov (United States)

    2006-06-01

    PROCESS Blue screening involving human filming usually employs a blue or green backdrop, since skin contains little blue or green hue. These backdrops...Helicopter Aircrew Training Using Fused Reality 27 - 10 RTO-MP-HFM-136 a. b. c. d. e. f. Figure 13: Frames Showing Physical Object ( witch ... filming . However, when a user’s hands disrupt the light from a helmet-mounted light source, the shadows cast onto the distant background are diffuse and

  15. Electrolysis of uranium tetrafluorure fused salts

    International Nuclear Information System (INIS)

    Perillo, P.M.; Botbol, J.

    1991-01-01

    Electrolytic preparation of U has been unsuccessful because the metal formed is in easily oxidized state. Electrolytic depositions were made under various conditions from fused NaCl-KCl baths containing UF 4 . X-ray diffraction studies were made of the products. The results indicate that mixed U with several oxides phases are produced. It was concluded that the method was unlikely to be efficient for the production of U metal. (Author) [es

  16. Design, Synthesis and Evaluation of Branched RRWQWR-Based Peptides as Antibacterial Agents Against Clinically Relevant Gram-Positive and Gram-Negative Pathogens

    Directory of Open Access Journals (Sweden)

    Sandra C. Vega

    2018-03-01

    Full Text Available Multidrug resistance of pathogenic bacteria has become a public health crisis that requires the urgent design of new antibacterial drugs such as antimicrobial peptides (AMPs. Seeking to obtain new, lactoferricin B (LfcinB-based synthetic peptides as viable early-stage candidates for future development as AMPs against clinically relevant bacteria, we designed, synthesized and screened three new cationic peptides derived from bovine LfcinB. These peptides contain at least one RRWQWR motif and differ by the copy number (monomeric, dimeric or tetrameric and structure (linear or branched of this motif. They comprise a linear palindromic peptide (RWQWRWQWR, a dimeric peptide (RRWQWR2KAhx and a tetrameric peptide (RRWQWR4K2Ahx2C2. They were screened for antibacterial activity against Enterococcus faecalis (ATCC 29212 and ATCC 51575 strains, Pseudomonas aeruginosa (ATCC 10145 and ATCC 27853 strains and clinical isolates of two Gram-positive bacteria (Enterococcus faecium and Staphylococcus aureus and two Gram-negative bacteria (Klebsiella pneumoniae and Pseudomonas aeruginosa. All three peptides exhibited greater activity than did the reference peptide, LfcinB (17–31, which contains a single linear RRWQWR motif. Against the ATCC reference strains, the three new peptides exhibited minimum inhibitory concentration (MIC50 values of 3.1–198.0 μM and minimum bactericidal concentration (MBC values of 25–200 μM, and against the clinical isolates, MIC50 values of 1.6–75.0 μM and MBC values of 12.5–100 μM. However, the tetrameric peptide was also found to be strongly hemolytic (49.1% at 100 μM. Scanning Electron Microscopy (SEM demonstrated that in the dimeric and tetrameric peptides, the RRWQWR motif is exposed to the pathogen surface. Our results may inform the design of new, RRWQWR-based AMPs.

  17. Peptide array-based interaction assay of solid-bound peptides and anchorage-dependant cells and its effectiveness in cell-adhesive peptide design.

    Science.gov (United States)

    Kato, Ryuji; Kaga, Chiaki; Kunimatsu, Mitoshi; Kobayashi, Takeshi; Honda, Hiroyuki

    2006-06-01

    Peptide array, the designable peptide library covalently synthesized on cellulose support, was applied to assay peptide-cell interaction, between solid-bound peptides and anchorage-dependant cells, to study objective peptide design. As a model case, cell-adhesive peptides that could enhance cell growth as tissue engineering scaffold material, was studied. On the peptide array, the relative cell-adhesion ratio of NIH/3T3 cells was 2.5-fold higher on the RGDS (Arg-Gly-Asp-Ser) peptide spot as compared to the spot with no peptide, thus indicating integrin-mediated peptide-cell interaction. Such strong cell adhesion mediated by the RGDS peptide was easily disrupted by single residue substitution on the peptide array, thus indicating that the sequence recognition accuracy of cells was strictly conserved in our optimized scheme. The observed cellular morphological extension with active actin stress-fiber on the RGD motif-containing peptide supported our strategy that peptide array-based interaction assay of solid-bound peptide and anchorage-dependant cells (PIASPAC) could provide quantitative data on biological peptide-cell interaction. The analysis of 180 peptides obtained from fibronectin type III domain (no. 1447-1629) yielded 18 novel cell-adhesive peptides without the RGD motif. Taken together with the novel candidates, representative rules of ineffective amino acid usage were obtained from non-effective candidate sequences for the effective designing of cell-adhesive peptides. On comparing the amino acid usage of the top 20 and last 20 peptides from the 180 peptides, the following four brief design rules were indicated: (i) Arg or Lys of positively charged amino acids (except His) could enhance cell adhesion, (ii) small hydrophilic amino acids are favored in cell-adhesion peptides, (iii) negatively charged amino acids and small amino acids (except Gly) could reduce cell adhesion, and (iv) Cys and Met could be excluded from the sequence combination since they have

  18. Albumin-derived peptides efficiently reduce renal uptake of radiolabelled peptides

    International Nuclear Information System (INIS)

    Vegt, Erik; Eek, Annemarie; Oyen, Wim J.G.; Gotthardt, Martin; Boerman, Otto C.; Jong, Marion de

    2010-01-01

    In peptide-receptor radionuclide therapy (PRRT), the maximum activity dose that can safely be administered is limited by high renal uptake and retention of radiolabelled peptides. The kidney radiation dose can be reduced by coinfusion of agents that competitively inhibit the reabsorption of radiolabelled peptides, such as positively charged amino acids, Gelofusine, or trypsinised albumin. The aim of this study was to identify more specific and potent inhibitors of the kidney reabsorption of radiolabelled peptides, based on albumin. Albumin was fragmented using cyanogen bromide and six albumin-derived peptides with different numbers of electric charges were selected and synthesised. The effect of albumin fragments (FRALB-C) and selected albumin-derived peptides on the internalisation of 111 In-albumin, 111 In-minigastrin, 111 In-exendin and 111 In-octreotide by megalin-expressing cells was assessed. In rats, the effect of Gelofusine and albumin-derived peptides on the renal uptake and biodistribution of 111 In-minigastrin, 111 In-exendin and 111 In-octreotide was determined. FRALB-C significantly reduced the uptake of all radiolabelled peptides in vitro. The albumin-derived peptides showed different potencies in reducing the uptake of 111 In-albumin, 111 In-exendin and 111 In-minigastrin in vitro. The most efficient albumin-derived peptide (peptide 6), was selected for in vivo testing. In rats, 5 mg of peptide 6 very efficiently inhibited the renal uptake of 111 In-minigastrin, by 88%. Uptake of 111 In-exendin and 111 In-octreotide was reduced by 26 and 33%, respectively. The albumin-derived peptide 6 efficiently inhibited the renal reabsorption of 111 In-minigastrin, 111 In-exendin and 111 In-octreotide and is a promising candidate for kidney protection in PRRT. (orig.)

  19. Therapeutic Potential of a Scorpion Venom-Derived Antimicrobial Peptide and Its Homologs Against Antibiotic-Resistant Gram-Positive Bacteria

    Directory of Open Access Journals (Sweden)

    Gaomin Liu

    2018-05-01

    Full Text Available The alarming rise in the prevalence of antibiotic resistance among pathogenic bacteria poses a unique challenge for the development of effective therapeutic agents. Antimicrobial peptides (AMPs have attracted a great deal of attention as a possible solution to the increasing problem of antibiotic-resistant bacteria. Marcin-18 was identified from the scorpion Mesobuthus martensii at both DNA and protein levels. The genomic sequence revealed that the marcin-18 coding gene contains a phase-I intron with a GT-AG splice junction located in the DNA region encoding the N-terminal part of signal peptide. The peptide marcin-18 was also isolated from scorpion venom. A protein sequence homology search revealed that marcin-18 shares extremely high sequence identity to the AMPs meucin-18 and megicin-18. In vitro, chemically synthetic marcin-18 and its homologs (meucin-18 and megicin-18 showed highly potent inhibitory activity against Gram-positive bacteria, including some clinical antibiotic-resistant strains. Importantly, in a mouse acute peritonitis model, these peptides significantly decreased the bacterial load in ascites and rescued nearly all mice heavily infected with clinical methicillin-resistant Staphylococcus aureus from lethal bacteremia. Peptides exerted antimicrobial activity via a bactericidal mechanism and killed bacteria through membrane disruption. Taken together, marcin-18 and its homologs have potential for development as therapeutic agents for treating antibiotic-resistant, Gram-positive bacterial infections.

  20. Inhibitory assay for degradation of collagen IV by cathepsin B with a surface plasmon resonance sensor.

    Science.gov (United States)

    Shoji, Atsushi; Suenaga, Yumiko; Hosaka, Atsushi; Ishida, Yuuki; Yanagida, Akio; Sugawara, Masao

    2017-10-25

    We describe a simple method for evaluating the inhibition of collagen IV degradation by cathepsin B with a surface plasmon resonance (SPR) biosensor. The change in the SPR signal decreased with an increase in the concentration of cathepsin B inhibitors. The order of the inhibitory constant (Ki) obtained by the SPR method was CA074Me≈Z-Phe-Phe-FMK < leupeptin. This order was different from that obtained by benzyloxycarbonyl-Phe-Phe-Fluoromethylketone (Z-Phe-Phe-FMK) as a peptide substrate. The comparison of Ki suggested that CA074 and Z-Phe-Phe-FMK inhibited exopeptidase activity, and leupeptin inhibited the endopeptidase activity of cathepsin B more strongly. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. The effect of high-pressure devitrification and densification on ballistic-penetration resistance of fused silica

    Science.gov (United States)

    Avuthu, Vasudeva Reddy

    Despite the clear benefits offered by more advanced transparent materials, (e.g. transparent ceramics offer a very attractive combination of high stiffness and high hardness levels, highly-ductile transparent polymers provide superior fragment-containing capabilities, etc.), ballistic ceramic-glass like fused-silica remains an important constituent material in a majority of transparent impact-resistant structures (e.g. windshields and windows of military vehicles, portholes in ships, ground vehicles and spacecraft) used today. Among the main reasons for the wide-scale use of glass, the following three are most frequently cited: (i) glass-structure fabrication technologies enable the production of curved, large surface-area, transparent structures with thickness approaching several inches; (ii) relatively low material and manufacturing costs; and (iii) compositional modifications, chemical strengthening, and controlled crystallization have been demonstrated to be capable of significantly improving the ballistic properties of glass. In the present work, the potential of high-pressure devitrification and densification of fused-silica as a ballistic-resistance-enhancement mechanism is investigated computationally. In the first part of the present work, all-atom molecular-level computations are carried out to infer the dynamic response and material microstructure/topology changes of fused silica subjected to ballistic impact by a nanometer-sized hard projectile. The analysis was focused on the investigation of specific aspects of the dynamic response and of the microstructural changes such as the deformation of highly sheared and densified regions, and the conversion of amorphous fused silica to SiO2 crystalline allotropic modifications (in particular, alpha-quartz and stishovite). The microstructural changes in question were determined by carrying out a post-processing atom-coordination procedure. This procedure suggested the formation of high-density stishovite (and

  2. Simulation of the evolution of fused silica's surface defect during wet chemical etching

    Science.gov (United States)

    Liu, Taixiang; Yang, Ke; Li, Heyang; Yan, Lianghong; Yuan, Xiaodong; Yan, Hongwei

    2017-08-01

    Large high-power-laser facility is the basis for achieving inertial confinement fusion, one of whose missions is to make fusion energy usable in the near future. In the facility, fused silica optics plays an irreplaceable role to conduct extremely high-intensity laser to fusion capsule. But the surface defect of fused silica is a major obstacle limiting the output power of the large laser facility and likely resulting in the failure of ignition. To mitigate, or event to remove the surface defect, wet chemical etching has been developed as a practical way. However, how the surface defect evolves during wet chemical etching is still not clearly known so far. To address this problem, in this work, the three-dimensional model of surface defect is built and finite difference time domain (FDTD) method is developed to simulate the evolution of surface defect during etching. From the simulation, it is found that the surface defect will get smooth and result in the improvement of surface quality of fused silica after etching. Comparatively, surface defects (e.g. micro-crack, scratch, series of pinholes, etc.) of a typical fused silica at different etching time are experimentally measured. It can be seen that the simulation result agrees well with the result of experiment, indicating the FDTD method is valid for investigating the evolution of surface defect during etching. With the finding of FDTD simulation, one can optimize the treatment process of fused silica in practical etching or even to make the initial characterization of surface defect traceable.

  3. Interactions of Bio-Inspired Membranes with Peptides and Peptide-Mimetic Nanoparticles

    Directory of Open Access Journals (Sweden)

    Michael Sebastiano

    2015-08-01

    Full Text Available Via Dissipative Particle Dynamics (DPD and implicit solvent coarse-grained (CG Molecular Dynamics (MD we examine the interaction of an amphiphilic cell-penetrating peptide PMLKE and its synthetic counterpart with a bio-inspired membrane. We use the DPD technique to investigate the interaction of peptide-mimetic nanoparticles, or nanopins, with a three-component membrane. The CG MD approach is used to investigate the interaction of a cell-penetrating peptide PMLKE with single-component membrane. We observe the spontaneous binding and subsequent insertion of peptide and nanopin in the membrane by using CG MD and DPD approaches, respectively. In addition, we find that the insertion of peptide and nanopins is mainly driven by the favorable enthalpic interactions between the hydrophobic components of the peptide, or nanopin, and the membrane. Our study provides insights into the mechanism underlying the interactions of amphiphilic peptide and peptide-mimetic nanoparticles with a membrane. The result of this study can be used to guide the functional integration of peptide and peptide-mimetic nanoparticles with a cell membrane.

  4. Current Peptide and Protein Candidates Challenging HIV Therapy beyond the Vaccine Era

    Directory of Open Access Journals (Sweden)

    Koollawat Chupradit

    2017-09-01

    Full Text Available Human immunodeficiency virus (HIV is a causative agent of acquired immune deficiency syndrome (AIDS. Highly active antiretroviral therapy (HAART can slow down the replication of HIV-1, leading to an improvement in the survival of HIV-1-infected patients. However, drug toxicities and poor drug administration has led to the emergence of a drug-resistant strain. HIV-1 immunotherapy has been continuously developed, but antibody therapy and HIV vaccines take time to improve its efficiency and have limitations. HIV-1-specific chimeric antigen receptor (CAR-based immunotherapy founded on neutralizing antibodies is now being developed. In HIV-1 therapy, anti-HIV chimeric antigen receptors showed promising data in the suppression of HIV-1 replication; however, autologous transfusion is still a problem. This has led to the development of effective peptides and proteins for an alternative HIV-1 treatment. In this paper, we provide a comprehensive review of potent anti-HIV-1 peptides and proteins that reveal promising therapeutic activities. The inhibitory mechanisms of each therapeutic molecule in the different stages of the HIV-1 life cycle will be discussed herein.

  5. Lactobacillus delbrueckii subsp. bulgaricus CRL 454 cleaves allergenic peptides of β-lactoglobulin.

    Science.gov (United States)

    Pescuma, Micaela; Hébert, Elvira M; Haertlé, Thomas; Chobert, Jean-Marc; Mozzi, Fernanda; Font de Valdez, Graciela

    2015-03-01

    Whey, a cheese by-product used as a food additive, is produced worldwide at 40.7 million tons per year. β-Lactoglobulin (BLG), the main whey protein, is poorly digested and is highly allergenic. We aimed to study the contribution of Lactobacillus delbrueckii subsp. bulgaricus CRL 454 to BLG digestion and to analyse its ability to degrade the main allergenic sequences of this protein. Pre-hydrolysis of BLG by L. delbrueckii subsp. bulgaricus CRL 454 increases digestion of BLG assayed by an in vitro simulated gastrointestinal system. Moreover, peptides from hydrolysis of the allergenic sequences V41-K60, Y102-R124, C121-L140 and L149-I162 were found when BLG was hydrolysed by this strain. Interestingly, peptides possessing antioxidant, ACE inhibitory, antimicrobial and immuno-modulating properties were found in BLG degraded by both the Lactobacillus strain and digestive enzymes. To conclude, pre-hydrolysis of BLG by L. delbrueckii subsp. bulgaricus CRL 454 has a positive effect on BLG digestion and could diminish allergenic reactions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Research on non-destructive testing (NDT) aerospace igniter fuse with neutron radiography (NR)

    International Nuclear Information System (INIS)

    Mo Dawei; Liu Yisi; Cai Qingsheng; Chen Boxian

    1995-01-01

    The research works, facilities and results of NDT aerospace igniter fuse with neutron radiography at Tsinghua University swimming-pool reactor are introduced. The image quality (NR) of ASTM E545-85 I level was approached. The NR experimental research of the typical and possible defects was performed. The theoretical analysis was performed too. The feasibility of NDT aerospace igniter fuse with NR was proved experimentally

  7. Demonstrating Earth Connections and Fuses Working Together

    Science.gov (United States)

    Harrison, Mark

    2017-01-01

    Earth wires and fuses work together in UK mains circuits to keep users safe from electric shocks and are taught in many school contexts. The subject can be quite abstract and difficult for pupils to grasp, and a simple but visually clear and direct demonstration is described which would be easy for most physics departments to build and which can…

  8. Neuropeptide delivery to the brain: a von Willebrand factor signal peptide to direct neuropeptide secretion

    Directory of Open Access Journals (Sweden)

    de Backer Marijke WA

    2010-08-01

    Full Text Available Abstract Background Multiple neuropeptides, sometimes with opposing functions, can be produced from one precursor gene. To study the roles of the different neuropeptides encoded by one large precursor we developed a method to overexpress minigenes and establish local secretion. Results We fused the signal peptide from the Von Willebrand Factor (VWF to a furin site followed by a processed form of the Agouti related protein (AgRP, AgRP83-132 or α-melanocyte stimulating hormone. In vitro, these minigenes were secreted and biologically active. Additionally, the proteins of the minigenes were not transported into projections of primary neurons, thereby ensuring local release. In vivo administration of VWF-AgRP83-132 , using an adeno-associated viral vector as a delivery vehicle, into the paraventricular hypothalamus increased body weight and food intake of these rats compared to rats which received a control vector. Conclusions This study demonstrated that removal of the N-terminal part of full length AgRP and addition of a VWF signal peptide is a successful strategy to deliver neuropeptide minigenes to the brain and establish local neuropeptide secretion.

  9. Hemi-fused structure mediates and controls fusion and fission in live cells.

    Science.gov (United States)

    Zhao, Wei-Dong; Hamid, Edaeni; Shin, Wonchul; Wen, Peter J; Krystofiak, Evan S; Villarreal, Seth A; Chiang, Hsueh-Cheng; Kachar, Bechara; Wu, Ling-Gang

    2016-06-23

    Membrane fusion and fission are vital for eukaryotic life. For three decades, it has been proposed that fusion is mediated by fusion between the proximal leaflets of two bilayers (hemi-fusion) to produce a hemi-fused structure, followed by fusion between the distal leaflets, whereas fission is via hemi-fission, which also produces a hemi-fused structure, followed by full fission. This hypothesis remained unsupported owing to the lack of observation of hemi-fusion or hemi-fission in live cells. A competing fusion hypothesis involving protein-lined pore formation has also been proposed. Here we report the observation of a hemi-fused Ω-shaped structure in live neuroendocrine chromaffin cells and pancreatic β-cells, visualized using confocal and super-resolution stimulated emission depletion microscopy. This structure is generated from fusion pore opening or closure (fission) at the plasma membrane. Unexpectedly, the transition to full fusion or fission is determined by competition between fusion and calcium/dynamin-dependent fission mechanisms, and is notably slow (seconds to tens of seconds) in a substantial fraction of the events. These results provide key missing evidence in support of the hemi-fusion and hemi-fission hypothesis in live cells, and reveal the hemi-fused intermediate as a key structure controlling fusion and fission, as fusion and fission mechanisms compete to determine the transition to fusion or fission.

  10. Synthesis, reactivity, and properties of N-fused porphyrin rhenium(I) tricarbonyl complexes.

    Science.gov (United States)

    Toganoh, Motoki; Ikeda, Shinya; Furuta, Hiroyuki

    2007-11-12

    The thermal reactions of N-fused tetraarylporphyrins or N-confused tetraarylporphyrins with Re2(CO)10 gave the rhenium(I) tricarbonyl complexes bearing N-fused porphyrinato ligands (4) in moderate to good yields. The rhenium complexes 4 are characterized by mass, IR, 1H, and 13C NMR spectroscopy, and the structures of tetraphenylporphynato complex 4a and its nitro derivative 15 are determined by X-ray single crystal analysis. The rhenium complexes 4 show excellent stability against heat, light, acids, bases, and oxidants. The aromatic substitution reactions of 4 proceed without a loss of the center metal to give the nitro (15), formyl (16), benzoyl (17), and cyano derivatives (19), regioselectively. In the electrochemical measurements for 4, one reversible oxidation wave and two reversible reduction waves are observed. Their redox potentials imply narrow HOMO-LUMO band gaps of 4 and are consistent with their electronic absorption spectra, in which the absorption edges exceed 1000 nm. Theoretical study reveals that the HOMO and LUMO of the rhenium complexes are exclusively composed of the N-fused porphyrin skeleton. Protonation of 4 takes place at the 21-position regioselectively, reflecting the high coefficient of the C21 atom in the HOMO orbital. The skeletal rearrangement reaction from N-confused porphyrin Re(I) complex (8) to N-fused porphyrin Re(I) complex (4) is suggested from the mechanistic study as well as DFT calculations.

  11. Composition Analysis and Inhibitory Effect of Sterculia lychnophora against Biofilm Formation by Streptococcus mutans

    Directory of Open Access Journals (Sweden)

    Yang Yang

    2016-01-01

    Full Text Available Pangdahai is a traditional Chinese drug, specifically described in the Chinese Pharmacopoeia as the seeds of Sterculia lychnophora Hance. Here, we separated S. lychnophora husk and kernel, analyzed the nutrient contents, and investigated the inhibitory effects of S. lychnophora ethanol extracts on cariogenic properties of Streptococcus mutans, important bacteria in dental caries and plaque formation. Ethanol extracts of S. lychnophora showed dose-dependent antibacterial activity against S. mutans with significant inhibition at concentrations higher than 0.01 mg/mL compared with the control group (p 0.03 mg/mL, while bacterial viability was decreased dose-dependently at high concentrations (0.04, 0.08, 0.16, and 0.32 mg/mL. Preliminary phytochemical analysis of the ethanol extract revealed a strong presence of alkaloid, phenolics, glycosides, and peptides while the presence of steroids, terpenoids, flavonoids, and organic acids was low. The S. lychnophora husk had higher moisture and ash content than the kernel, while the protein and fat content of the husk were lower (p<0.05 than those of the kernel. These results indicate that S. lychnophora may have antibacterial effects against S. mutans, which are likely related to the alkaloid, phenolics, glycosides, and peptides, the major components of S. lychnophora.

  12. Immunization with a novel chimeric peptide representing B and T cell epitopes from HER2 extracellular domain (HER2 ECD) for breast cancer.

    Science.gov (United States)

    Mahdavi, Manijeh; Keyhanfar, Mehrnaz; Jafarian, Abbas; Mohabatkar, Hassan; Rabbani, Mohammad

    2014-12-01

    Because of direct stimulating immune system against disease, vaccination or active immunotherapy is preferable compared to passive immunotherapy. For this purpose, a newly designed chimeric peptide containing epitopes for both B and T cells from HER2 ECD subdomain III was proposed. To evaluate the effects of the active immunization, a discontinuous B cell epitope peptide was selected based on average antigenicity by bioinformatics analysis. The selected peptide was collinearly synthesized as a chimera with a T helper epitope from the protein sequence of measles virus fusion (208-302) using the GPSL linker. Three mice were immunized with the chimeric peptide. Reactive antibodies with HER2 protein in ELISA and immunofluorescence assays with no cross-reactivity were generated. The 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay indicated that the anti-peptide sera had inhibitory effects on proliferation of SK-BR-3 cells. Hence, the newly designed, discontinuous chimeric peptide representing B and T cell epitopes from subdomain III of HER2-ECD can form the basis for future vaccines design, where these data can be applied for monoclonal antibody production targeting the distinct epitope of HER2 receptor compared to the two broadly used anti-HER2 monoclonal antibodies, Herceptin and pertuzumab.

  13. Fungal Systematics and Evolution: FUSE 1

    OpenAIRE

    Crous, Pedro W; Schumacher, René K; Wingfield, Michael J; Lombard, Lorenzo; Giraldo, Alejandra; Christensen, Martha; Gardiennet, Alain; Nakashima, Chiharu; Pereira, Olinto L; Smith, Alexander J; Groenewald, Johannes Z

    2015-01-01

    Fungal Systematics and Evolution (FUSE) is introduced as a new series to expedite the publication of issues relating to the epitypification of formerly described species, report new sexual-asexual connections, the merging of sexual and asexual gen¬era following the end of dual nomenclature, and to describe species or note interesting observations regarding fungi. This first paper includes 18 new combinations, 13 new species, three new genera and one new family. All taxa are ascomycetes, excep...

  14. [Plant signaling peptides. Cysteine-rich peptides].

    Science.gov (United States)

    Ostrowski, Maciej; Kowalczyk, Stanisław

    2015-01-01

    Recent bioinformatic and genetic analyses of several model plant genomes have revealed the existence of a highly abundant group of signaling peptides that are defined as cysteine-rich peptides (CRPs). CRPs are usually in size between 50 and 90 amino acid residues, they are positively charged, and they contain 4-16 cysteine residues that are important for the correct conformational folding. Despite the structural differe