WorldWideScience

Sample records for enzyme histochemical studies

  1. Direct comparison of enzyme histochemical and immunohistochemical methods to localize an enzyme

    NARCIS (Netherlands)

    van Noorden, Cornelis J. F.

    2002-01-01

    Immunohistochemical localization of enzymes is compared directly with localization of enzyme activity with (catalytic) enzyme histochemical methods. The two approaches demonstrate principally different aspects of an enzyme. The immunohistochemical method localizes the enzyme protein whether it is

  2. Histochemical study of the distribution of a few enzymes in the digestive system of Indian parrot.

    Science.gov (United States)

    Mohan, K; Agrawal, V P; Goel, K A

    1977-01-01

    Acid-and alkaline phosphatase, 5-nucleotidase and lipase have been localized histochemically in the gizzard, intestine liver and pancreas of Indian parrot, Psittacula krameri. In the gizzard and intestine, the mucosal epithelial cells are the main sites for the enzyme production. The tubular glands of the gizzard show intense reaction for all the enzymes tested. The hepatic sinusoid cells of the liver and the acinii of pancreas give positive reaction. Like pancreas, the intestine has also been found responsible for the production and secretion of lipase. Functional significance of phosphatases in the tissues tested has been discussed.

  3. Fabry's disease: biochemical and histochemical studies on hair roots for carrier detection.

    Science.gov (United States)

    Vermorken, A J; Weterings, P J; Spierenburg, G T; vanBennekom, C A; Wirtz, P; deBruyn, C H; Oei, T L

    1978-02-01

    A method of assay alpha-galactosidase and acid phosphatase activities in single hair roots is described. Enzyme histochemical studies show that the distribution of acid phosphatase in the human hair root matches that of alpha-galactosidase. Histochemically, the main activity is located in the upper part of the sheath near the orifice of the duct of the sebaceous gland. This is confirmed by enzyme assays on different parts of the hair root after dissection. The variation in the values found in individual hair roots is improved by relating alpha-galactosidase to acid phosphatase activities. Storage experiments indicate a remarkable stability of both alpha-galactosidase and acid phosphatase in human hair roots.

  4. Histochemical Studies of the Effects of Monosodium Glutamate on ...

    African Journals Online (AJOL)

    Uche

    Key words: Monosodium glutamate; histochemical effect; liver enzymes; hepatocytes; atrophic and degenerative changes;. Wistar rats. ... disease, Huntington‟s disease, and amyotrophic ... ascending grade of alcohol (ethanol), cleared in.

  5. Study of the histochemical detection of cysteine desulfhydrase in the vitellin sac of birds (1961)

    International Nuclear Information System (INIS)

    Chapeville, F.; Khau Van Kien, L.

    1961-01-01

    We have developed a method for the histochemical detection of cysteine desulfhydrase in the vitellin sac of the chicken embryo. The enzyme is localized in the presence of a lead salt by lead sulphide formed in situ from hydrogen sulphide liberated from the cysteine. The micrographs obtained are histological and show the presence of the enzyme in the different types of endoderm cell. (authors) [fr

  6. A quantitative histochemical procedure for the demonstration of purine nucleoside phosphorylase activity in rat and human liver using Tetranitro BT and xanthine oxidase as auxiliary enzyme

    NARCIS (Netherlands)

    Frederiks, W. M.; Bosch, K. S.; van Gulik, T.

    1993-01-01

    A quantitative histochemical procedure was developed for the demonstration of purine nucleoside phosphorylase in rat liver using unfixed cryostat sections and the auxiliary enzyme xanthine oxidase. The optimum incubation medium contained 18% (w/v) poly(vinyl alcohol), 100 mM phosphate buffer, pH

  7. Histochemical studies on genetical control of hormonal enzyme inducibility in the mouse. IV: Cellular localization of androgen sensitive nonspecific esterase in the epididymis

    DEFF Research Database (Denmark)

    Kirkeby, S; Blecher, S R

    1981-01-01

    Nonspecific esterase of mouse epididymis has previously been studied histochemically, using alpha naphthyl-acetate and 5-bromoindoxyl acetate techniques, as well as certain inhibitors. Epithelial cell types of the epididymis have been characterized, and certain esterase isozymes in a particular...

  8. Histochemical Study of the Progenetic Trematode Alloglossidium renale

    Directory of Open Access Journals (Sweden)

    Craig A. Schimmer

    2014-01-01

    Full Text Available A histochemical study of the progenetic trematode Alloglossidium renale has demonstrated the absence of any secreted material between the adult worm and the host (freshwater shrimp antennal gland tubules. Host tissue is affected only by the compression, abrasion, and ingestion by the parasite, and host tubule cells near the worm have the same staining patterns as those distant from the parasite. The trematode sometimes dies within the host, leaving a necrotic mass whose histochemical staining differs significantly from the living organism. In the necrotic mass, the only recognizable features were the ova and the vitellarium, which atrophied and resulted in tyrosine-positive staining within the mass. A melanin reaction was not observed in the host using a specialized ferro-ferricyanide stain. The only apparent host response to infection was a layer of damaged squamous host cells adhering to the necrotic worm. The results confirm benign host-parasite effects and a highly evolved relationship between the host and parasite, perhaps bordering on commensalism.

  9. Histochemical location of key enzyme activities involved in receptivity and self-incompatibility in the olive tree (Olea europaea L.).

    Science.gov (United States)

    Serrano, Irene; Olmedilla, Adela

    2012-12-01

    Stigma-surface and style enzymes are important for pollen reception, selection and germination. This report deals with the histochemical location of the activity of four basic types of enzyme involved in these processes in the olive (Olea europaea L.). The detection of peroxidase, esterase and acid-phosphatase activities at the surface of the stigma provided evidence of early receptivity in olive pistils. The stigma maintained its receptivity until the arrival of pollen. Acid-phosphatase activity appeared in the style at the moment of anthesis and continued until the fertilization of the ovule. RNase activity was detected in the extracellular matrix of the styles of flowers just before pollination and became especially evident in pistils after self-pollination. This activity gradually decreased until it practically disappeared in more advanced stages. RNase activity was also detected in pollen tubes growing in pollinated pistils and appeared after in vitro germination in the presence of self-incompatible pistils. These findings suggest that RNases may well be involved in intraspecific pollen rejection in olive flowers. To the best of our knowledge this is the first time that evidence of enzyme activity in stigma receptivity and pollen selection has been described in this species. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  10. The human amygdaloid complex: a cytologic and histochemical atlas using Nissl, myelin, acetylcholinesterase and nicotinamide adenine dinucleotide phosphate diaphorase staining.

    Science.gov (United States)

    Sims, K S; Williams, R S

    1990-01-01

    We examined the distribution of acetylcholinesterase and nicotinamide adenine dinucleotide phosphate diaphorase enzyme activity in the human amygdala using histochemical techniques. Both methods revealed compartments of higher or lower enzyme activity, in cells or neuropil, which corresponded to the nuclear subdivisions of the amygdala as defined with classical Nissl and myelin methods. The boundaries between the histochemical compartments were usually so sharp that the identification of these nuclear subdivisions was enhanced. There was also variation of staining intensity within many of the nuclear subdivisions, such as the lateral and central nuclei, anterior amygdaloid area and the intercalated groups. This histochemical difference corresponded to more subtle differences in Nissl and myelin staining patterns, and suggests further structural subdivisions of potential functional significance. We present a revised scheme of anatomical parcellation of the human amygdala based upon serial analysis with all four techniques. Our expectation is that this will allow the delineation of a clearer homology between the cytoarchitectonic subdivisions of the human amygdala and those of experimental animals.

  11. Histochemical and ultrastructural studies on the calcareous corpuscles and eggs of Taenia taeniaeformis and Dipylidium caninum.

    Science.gov (United States)

    Khalifa, Refaat M A; Mazen, Nawal A M; Marawan, Aziza M A; Thabit, Hasnaa T M

    2011-08-01

    Calcareous corpuscles were noticed by several previous workers to be present in larval and adult cestodes without knowing their function. However, nothing was mentioned in the available literature about distribution of these corpuscles and their density, structure and composition in different parts of the body of different cestodes. Hence, in the present work, a comparative study of their distribution, density, histochemical and ultrastructural characters in different parts of the body was performed in Taenia taeniaeformis and Dipylidium caninum. Due to the presence of the eggs in their gravid segments, their histochemical and ultrastructural characteristics were also studied. It was found that the size, location and density of the calcareous bodies were different in different body parts of the same and the other cestode. Histochemically, the main component of these corpuscles was calcium; while other constituents as polysaccharides, lipids, protrins and mucopolysaccharides were found in their outer rim. Ultrastructurally, they were quite similar in the two studied cestodes and different stages of their development were exhibited. Histochemically, the eggs of both cestodes were similar in their contents. However, some ultrastructural differences have been demonstrated particularly in relation to the size and shape of the rods in the embryophore and the structures in between the embryophore and onchosphere.

  12. Histochemical demonstration of mercury induced changes in rat neurons

    DEFF Research Database (Denmark)

    Danscher, G; Schrøder, H D

    1979-01-01

    A histochemical method modified for ultrastructural studies of mercury induced changes is described. Rat neurons from areas known to be influenced by mercury are used as examples. The histochemical reaction, suggested to be caused by polymercury sulphide complexes, is localized to "dense bodies......" where it is visible 14 days after initiation of peroral mercury treatment (20 mg HgCl2/l drinking water)....

  13. Histochemical and radioautographic studies of normal human fetal colon

    International Nuclear Information System (INIS)

    Lev, R.; Orlic, D.; New York Medical Coll., N.Y.

    1974-01-01

    Twenty fetal and infant colons ranging from 10 weeks in utero to 20 months postpartum, and 12 adult human colons were examined using histochemical techniques in conjunction with in vitro radioautography using Na 2 35 SO 4 as a sulfomucin precursor. Only the sulfated components of mucus in fetal goblet cells was found to differ significantly from adult colonic mucins. In the fetus sulfomucin staining was much weaker than in the adult, and was more intense in the left colon which is the reverse of the adult pattern. Sulfomucin was concentrated in the crypts throughout the fetal colon whereas in the adult right colon it predominated in the surface cells. As in the adult, saponification liberated carboxyl groups, possibly belonging to sialic acid, and vicinal hydroxyl groups from fetal mucins suggesting that this procedure hydrolyses an ester linkage between these 2 reactive groups. During the middle trimester of fetal life the colon possesses villi whose constituent cells display alkaline phosphatase in their surface coat. These and other morphological and histochemical similarities to fetal small intestine suggest that the fetal colon may have a limited capacity to absorb materials contained within swallowed amniotic fluid during this period. (orig.) [de

  14. Structural and histochemical studies on the effect of injectable contraceptive on some parenchymatous organs of female albino rats

    International Nuclear Information System (INIS)

    Essa, O.S.M.

    1998-01-01

    This work was planned to evaluate the histopathological and histochemical changes induced by gamma irradiation and or long acting injectable contraceptive ( depo-provera) MPa on some parenchymatous organs of female rats as well as testing the degree of reversibility of changes that may be develop in such organs. The plan of this study was designed for the following: 1- Study of the morphological changes in the liver, kidney and gonadotrophs cell. 2- study of the effect of gamma radiation and/or MPa on the vascular distribution in the liver and kidney tissues, using indian ink injection technique. 3- evaluation of the activity of two enzymes ( acid phosphatase and succinic dehydrogenase) in the liver and kidney tissues. This was accomplished using frozen sections . Moreover, evaluation of the Pas + ve materials using paraffin sections in the same organs. 4- quantitative study was performed for P As + ve materials, acid phosphatase and succinic dehydrogenase in addition to the vascular distribution in the liver and kidney tissues. furthermore, quantitative measurement for FSH and LH cells using immunostaining method

  15. The influence of temperature on the distribution and intensity of the reaction product in rat muscle fibers obtained with the histochemical method for myosin ATPase

    DEFF Research Database (Denmark)

    Kirkeby, S; Tuxen, A

    1989-01-01

    The influence of temperature in the incubation medium on the localization and intensity of myosin ATPase was investigated in striated muscles from the rat using a conventional histochemical technique. It was found that the enzyme reaction was temperature-dependent since the activity in some fibers...... was raised and in others was depressed by alteration of the incubation temperature. There was no obvious correlation between the temperature sensitivity of ATPase in the muscle fibers and their activity for succinic dehydrogenase. It is proposed that the histochemical method for myosin ATPase can be used...

  16. Histochemical effects of γ radiation on soft fruit cell walls

    International Nuclear Information System (INIS)

    Foa, E.; Jona, R.; Vallania, R.

    1980-01-01

    Irradiation effects in peaches, tomatoes, cherries and grapes on the composition of cell wall polysaccharides were investigated by histochemical techniques. Cell wall polysaccharides, separated by a modified Jensen's method were pectins, hemicellulose, non-cellulosic polysaccharides and cellulose. The extinction values of Periodic Acid Schiff stained tissues was measured by microscopical photometry. Irradiation induced highly significant changes in polysaccharide composition of mesocarp cell walls; these changes were found to be a function of time of irradiation after harvest and of the species tested. A general influence on polysaccharide molecules was not found. Variations produced by irradiation are postulated to be an interference with a regulatory system rather than a breakdown of a functional molecule (metabolic enzyme or polysaccharide. (author)

  17. Electron histochemical and autoradiographic studies of vascular smooth muscle cell

    International Nuclear Information System (INIS)

    Kameyama, Kohji; Aida, Takeo; Asano, Goro

    1982-01-01

    The authors have studied the vascular smooth muscle cell in the aorta and the arteries of brain, heart in autopsied cases, cholesterol fed rabbits and canine through electron histochemical and autoradiographic methods, using 3 H-proline and 3 H-thymidine. The vascular changes are variable presumably due to the functional and morphological difference of vessels. Aging, pathological condition and physiological requirement induce the disturbances of vascular functions as contractility. According to various pathological conditions, the smooth muscle cell altered their shape, surface properties and arrangement of subcellular organelles including changes in number. The morphological features of arteries during aging is characterized by the thickening of endothelium and media. Decreasing cellularity and increasing collagen contents in media. The autoradiographic and histochemical observations using periodic acid methenamine silver (PAM) and ruthenium red stains demonstrated that the smooth muscle cell is a connective tissue synthetic cell. The PAM impregnation have proved that the small bundle of microfilaments become associated with small conglomerate of collagen and elastic fibers. Cytochemical examination will provide sufficient evidence to establish the contribution of subcellular structure. The acid phosphatase play an important role in vascular disease and they are directly involved in cellular lipid metabolism in cholesterol fed animals, and the activity of Na-K ATPase on the plasma membrane may contribute to the regulation of vascular blood flow and vasospasms. Direct injury and subsequent abnormal contraction of smooth muscle cell may initiate increased permeability of plasma protein and lipid in the media layer and eventually may developed and enhance arteriosclerosis. (author)

  18. Ultrastructural and Histochemical Characterization of the Zebra Mussel Adhesive Apparatus

    Science.gov (United States)

    Farsad, Nikrooz

    Since their accidental introduction into the Great Lakes in mid- to late-1980s, the freshwater zebra mussels, Dreissena polymorpha, have colonized most lakes and waterways across eastern North America. Their rapid spread is partly attributed to their ability to tenaciously attach to hard substrates via an adhesive apparatus called the byssus, resulting in serious environmental and economic impacts. A detailed ultrastructural study of the byssus revealed a 10 nm adhesive layer at the attachment interface. Distributions of the main adhesive amino acid, 3,4-dihydroxyphenylalanine (DOPA), and its oxidizing (cross-linking) enzyme, catechol oxidase, were determined histochemically. It was found that, upon aging, DOPA levels remained high in the portion of the byssus closest to the interface, consistent with an adhesive role. In contrast, reduced levels of DOPA corresponded well with high levels of catechol oxidase in the load-bearing component of the byssus, presumably forming cross-links and increasing the cohesive strength.

  19. A histochemical study of the posterior silk glands of Bombyx mori during metamorphosis from larvae to pupae using frozen sections.

    Science.gov (United States)

    Kawamoto, K; Kawamoto, T; Shiba, H; Hosono, K

    2014-02-01

    The fine structures of the whole bodies and the posterior silk glands of Bombyx mori during metamorphosis from larvae to pupae in the cocoon were preserved virtually without damage when frozen sections were prepared using an adhesive plastic film. We used frozen sections for histochemical and enzyme histochemistry to characterize the metamorphosis of the posterior silk glands. Frozen sections were stained with DAPI to observe nuclear changes, examined using the TUNEL method to detect DNA fragments, and investigated using in situ hybridization to detect B. mori caspase expression. Both DNA fragments and expression of B. mori caspase increased with progressing metamorphosis. The degeneration of the posterior silk gland during metamorphosis appears to be an apoptotic event.

  20. Quantitative aspects of enzyme histochemistry on sections of freeze-substituted glycol methacrylate-embedded rat liver

    NARCIS (Netherlands)

    Frederiks, W. M.; Bosch, K. S.

    1993-01-01

    Freeze-substituted rat liver embedded in glycol methacrylate (GMA) has been used to demonstrate the activities of several enzymes. The following enzymes could be detected in GMA-sections by the indicated histochemical procedure(s): 5'-nucleotidase (lead salt, cerium-diaminobenzidine), alkaline

  1. [Histochemical and histoenzymatic study of experimental endarteritis in rabbits. I. Femoral endarteritis].

    Science.gov (United States)

    Abou-Haila, A; Hadjiisky, P; Roland, J; Orcel, L

    1978-04-01

    The parietal reaction after placing a cuff of polyethylene around the femoral artery has been studied in 18 (2,5 - 3 months old) male rabbits by using histologic, histochemical (4 macromolecular substances) and histoenzymatic techniques (16 enzymatic activities). Studies were performed on the 1st, 3rd, 5th, 15th and 21st day, and every 15 days during the 3 months of the experiment. This process induced rapidly in each animal a parietal reaction with adventitial oedema (1st day), hypoxia of the media (1st -5th day), cytoenzymatic activation followed by a cellular transformation and proliferation of the intima-media, that forms a diffuse intimal thickening (adaptation). Most cells of the thickening were, by their enzymatic activities, quite comparable to immature smooth muscle cells, which probably emigrated from the media: intense LDH, NADH2 - TR; moderate G6P-DH, SDH, NADPH2 - TR, alpha-GP-DH, ATP/ase; weak ICHD, beta-HB-DH. Moreover, some reactions (accentuation of beta-Glu/ase, UDGP-DH, Glu-DH, 5'N/ase) besides suggested the active participation of the cells in the production of extracellular conjonctive constituents, because the histochemical studies revealed the presence of metachromatic glycosamino-glycanes and positive APS substances during the edification of the diffuse intimal thickening. In advanced thickening, an histoenzymatic duality was observed, that might prove the double origin of the thickening cells: some superficial cells had the enzymatic characteristics of endothelial cells (increased activity of aerobic oxydoreductases). At every stage of the study, the thickening cells differed from the atherocytes by a lack of lipids in their cytoplasm.

  2. Xanthine, hypoxanthine and muscle pain. Histochemical and biochemical observations

    Energy Technology Data Exchange (ETDEWEB)

    Isaacs, H; Badenhorst, M; Pickering, A [University of the Witwatersrand, Johannesburg (South Africa). Department of Physiology; Heffron, J J.A. [University of the Witwatersrand, Johannesburg (South Africa). Department of Physiological Chemistry; Berman, L

    1975-06-21

    A suspected case of xanthine oxidase deficiency has been further investigated. The patient complained of arthralgia and myalgia. Further studies included histochemical and ultramicroscopic analysis of muscle sarcoplasmic recticulum, and biochemical studies. High levels of xanthine and hypoxanthine were found, while uric acid was absent in the muscle extracts.

  3. A Structural and Histochemical Study of Actinorhizal Nodules of Casuarina equisetifolia Linn.

    Directory of Open Access Journals (Sweden)

    Mohammad Athar

    2001-03-01

    Full Text Available Casuarina equisetifolia Linn. is an introduced actinorhizal plant grown as roadside ornamental tree and as forest plantation in Pakistan. Actinorhizal nodules are formed on the roots of C. equisetifolia as a response to infection by Frankia. Structure of C. equisetifolia nodules is described using histochemical methods to elucidate the nature of micro-symbiont within the nodules. C. equisetifolia nodules were similar to a root in general anatomical structure and resembled with Myrica-type nodules. The nodule consisted of a distinct periderm enclosing the cortex. The cortex showed patches of infected cells interspersed among uninfected ones. Inside the cortex there was a stele bounded by an endodermis, which contained tannins. The phloem-xylem relationship was amphicribral. A poorly defined meristem was also observed. Apart from simple nodules, dichotomously branched and coralloid nodules were also observed. The stele in simple and branched nodules reached up to the tip of the nodules. The micro-symbiont was observed in the nodule tissues in hyphal form only. The histochemical tests revealed absence of vacuoles and starch grains, and presence of tannins and lignin.

  4. Histochemical Characterization of Rain-Forest Strain of Onchocerca ...

    African Journals Online (AJOL)

    Abstract: The histochemical characterization of rain-forest strain of Onchocerca volvulus isolated in Akamkpa of Cross River State, Nigeria was studied. In a preliminary survey of 350 persons from eight villages, 75(21.4%) were found to be positive for the parasite. Males (23.6%) were more infected than the females but there ...

  5. Lemna minor exposed to fluoranthene: growth, biochemical, physiological and histochemical changes.

    Science.gov (United States)

    Zezulka, Stěpán; Kummerová, Marie; Babula, Petr; Váňová, Lucie

    2013-09-15

    Polycyclic aromatic hydrocarbons (PAHs) represent one of the major groups of organic contaminants in the aquatic environment. Duckweed (Lemna minor L.) is a common aquatic plant widely used in phytotoxicity tests for xenobiotic substances. The goal of this study was to assess the growth and the physiological, biochemical and histochemical changes in duckweed exposed for 4 and 10 days to fluoranthene (FLT, 0.1 and 1 mgL(-1)). Nonsignificant changes in number of plants, biomass production, leaf area size, content of chlorophylls a and b and carotenoids and parameters of chlorophyll fluorescence recorded after 4 and 10 days of exposure to FLT were in contrast with considerable changes at biochemical and histochemical levels. Higher occurrence of reactive oxygen species (ROS) caused by an exposure to FLT after 10 days as compared to control (hydrogen peroxide elevated by 13% in the 0.1 mgL(-1) and by 41% in the 1 mgL(-1) FLT; superoxide anion radical by 52% and 115% respectively) reflected in an increase in the activities of antioxidant enzymes (superoxide dismutase by 3% in both treatments, catalase by 9% and 1% respectively, ascorbate peroxidase by 21% and 5% respectively, guaiacol peroxidase by 12% in the 0.1 mgL(-1) FLT). Even the content of antioxidant compounds like ascorbate (by 20% in the 1 mgL(-1) FLT) or total thiols (reduced forms by 15% in the 0.1 mgL(-1) and 8% in the 1 mgL(-1) FLT, oxidized forms by 36% in the 0.1 mgL(-1) FLT) increased. Increased amount of ROS was followed by an increase in malondialdehyde content (by 33% in the 0.1 mgL(-1) and 79% in the 1 mgL(-1) FLT). Whereas in plants treated by the 0.1 mgL(-1) FLT the contents of total proteins and phenols increased by 15% and 25%, respectively, the 1 mgL(-1) FLT caused decrease of their contents by 32% and 7%. Microscopic observations of duckweed roots also confirmed the presence of ROS and related histochemical changes at the cellular and tissue levels. The assessment of phytotoxicity of organic

  6. Immunohistochemical/histochemical double staining method in the study of the columnar metaplasia of the oesophagus

    Directory of Open Access Journals (Sweden)

    D. Cabibi

    2014-03-01

    Full Text Available Intestinal metaplasia in Barrett’s oesophagus (BO represents an important risk factor for oesophageal adenocarcinoma. Instead, few and controversial data are reported about the progression risk of columnar-lined oesophagus without intestinal metaplasia (CLO, posing an issue about its clinical management. The aim was to evaluate if some immunophenotypic changes were present in CLO independently of the presence of the goblet cells. We studied a series of oesophageal biopsies from patients with endoscopic finding of columnar metaplasia, by performing some immunohistochemical stainings (CK7, p53, AuroraA combined with histochemistry (Alcian-blue and Alcian/PAS, with the aim of simultaneously assess the histochemical features in cells that shows an aberrant expression of such antigens. We evidenced a cytoplasmic expression of CK7 and a nuclear expression of Aurora A and p53,  both in goblet cells of BO and in non-goblet cells of CLO, some of which showing mild dysplasia. These findings suggest that some immunophenotypic changes are present in CLO and they can precede the appearance of the goblet cells or can be present independently of them, confirming the conception of BO as the condition characterized by any extention of columnar epithelium. This is the first study in which a combined immunohistochemical/histochemical method has been applied to Barrett pathology.

  7. Is there still room for novelty, in histochemical papers?

    Directory of Open Access Journals (Sweden)

    Carlo Pellicciari

    2016-12-01

    Full Text Available Histochemistry continues to be widely applied in biomedical research, being nowadays mostly addressed to detect and locate single molecules or molecular complexes inside cells and tissues, and to relate structural organization and function at the high resolution of the more advanced microscopical techniques. In the attempt to see whether histochemical novelties may be found in the recent literature, the articles published in the European Journal of Histochemistry in the period 2014-2016 have been reviewed. In the majority of the published papers, standardized methods have been preferred by scientists to make their results reliably comparable with the data in the literature, but  many papers (approximately one fourth of the published articles described novel histochemical methods and procedures.  It is worth noting that there is a growing interest for minimally-invasive in vivo techniques (magnetic resonance imaging, autofluorescence spectroscopy which may parallel conventional  histochemical analyses to obtain information not only on the morphological features of living organs and tissues, but also on their functional, biophysical and molecular characteristics. Thanks to this unceasing methodological refinement, histochemistry will continue to provide innovative applications in the biomedical field.

  8. Histochemical study on effects of low dose γ-irradiation on acid phosphatase in liver of the pigeons Columbus livia intermedia Strickland

    International Nuclear Information System (INIS)

    Gadhia, P.K.; Shah, V.C.

    1982-01-01

    Effects of total body γ-irradiation with sub-lethal dose (400 rads) on acid phosphatase have been studied in the liver of pigeon. The histochemical study showed increased activity of acid phosphatase in liver after 48 hr and 72 hr of irradiation. (author)

  9. Morphological, Histological and Histochemical Study of the Lingual Salivary Glands of the Little Egret, Egretta garzetta

    International Nuclear Information System (INIS)

    Almansour, Mansour I.; Jarrar, Bashir M.

    2007-01-01

    The present study aimed to study the morphological, histological and histochemical characterizations of the lingual salivary glands of the little egret, Egretta garzetta. The glands are composed of two posterior entities at the base of the tongue and one anterior entity on the dorsal surface of the free lingual part. These glands are made of mucoserous cells that elaborate sialomucins, sulfomucins and proteins, but they are devoid of glycogen and neutral mucosubstances. The findings of the present study were compared with those reported for other birds in correlation with their phylogeny and feeding habits. (author)

  10. Elastofibroma dorsi: a histochemical and immunohistochemical study

    Directory of Open Access Journals (Sweden)

    A. Di Vito

    2015-02-01

    Full Text Available Elastofibroma dorsi (ED is considered a member of a heterogeneous group of benign fibrous (fibroblastic or myofibroblastic soft-tissue tumors, frequently localized in the periscapular region in middle aged or older individuals. However, the pathogenesis of ED is still unclear and many authors believe that ED results from a reactive hyperproliferation of fibroblastic tissue, while others suggest that it may be a consequence of a mechanical friction. In our study, we examined 11 cases of ED using histochemical and immunohistochemical methods, in order to extend the knowledge about extracellular matrix composition and histopathogenesis of ED. From the results it appeared that stroma and interspersed spindle cells of ED were positive for both periostin and tenascin-C. Mast cells tryptase-positive were also abundant throughout the lesion. The perivascular distribution of periostin and tenascin-C, associated with the CD34 positivity, suggest that endothelial-mesenchymal transition events can account for neovascularization and production of fibroelastic tissue characteristic of elastofibroma. Our data obtained in endothelial cells cultures demonstrated that elastin production is higher when the status of confluence of the cells is low. So, we can assume that such a phenomenon is a characteristic of mesenchymal/endothelial cells CD34 positive, in which elastin production results to be inversely proportional to the vascular differentiation of cellular elements. In the light of these considerations, we think that a cancerous nature of ED is unlikely. Overall, our study report, for the first time, a detailed description of extracellular matrix composition in ED, suggesting that a mechanical strain-dependent reactivation of periostin and tenascin-C expression, as well as of elastin deposition, could be responsible for development of ED.

  11. Histological and histochemical study of the protective role of rosemary extract against harmful effect of cell phone electromagnetic radiation on the parotid glands.

    Science.gov (United States)

    Ghoneim, Fatma M; Arafat, Eetmad A

    2016-06-01

    Electromagnetic fields (EMFs) are a class of non-ionizing radiation (NIR) that is emitted from mobile phone. It may have hazardous effects on parotid glands. So, we aimed to investigate the histological and histochemical changes of the parotid glands of rats exposed to mobile phone and study the possible protective role of rosemary against its harmful effect. Forty adult male albino rats were used in this study. They were classified into 4 equal groups. Group I (control), group II (control receiving rosemary), group III (mobile phone exposed group) and group IV (mobile exposed, rosemary treated group). Parotid glands were dissected out for histological and histochemical study. Moreover, measurement of oxidative stress markers; malondialdehyde (MDA) and total antioxidant capacity (TAC) was done. The results of this study revealed that rosemary has protective effect through improving the histological and histochemical picture of the parotid gland in addition of its antioxidant effect. It could be concluded from the current study, that exposure of parotid gland of rat models to electromagnetic radiation of mobile phone resulted in structural changes at the level of light and electron microscopic examination which could be explained by oxidative stress effect of mobile phone. Rosemary could play a protective role against this harmful effect through its antioxidant activity. Copyright © 2016 Elsevier GmbH. All rights reserved.

  12. Finding an optimum immuno-histochemical feature set to distinguish benign phyllodes from fibroadenoma.

    Science.gov (United States)

    Maity, Priti Prasanna; Chatterjee, Subhamoy; Das, Raunak Kumar; Mukhopadhyay, Subhalaxmi; Maity, Ashok; Maulik, Dhrubajyoti; Ray, Ajoy Kumar; Dhara, Santanu; Chatterjee, Jyotirmoy

    2013-05-01

    Benign phyllodes and fibroadenoma are two well-known breast tumors with remarkable diagnostic ambiguity. The present study is aimed at determining an optimum set of immuno-histochemical features to distinguish them by analyzing important observations on expressions of important genes in fibro-glandular tissue. Immuno-histochemically, the expressions of p63 and α-SMA in myoepithelial cells and collagen I, III and CD105 in stroma of tumors and their normal counterpart were studied. Semi-quantified features were analyzed primarily by ANOVA and ranked through F-scores for understanding relative importance of group of features in discriminating three classes followed by reduction in F-score arranged feature space dimension and application of inter-class Bhattacharyya distances to distinguish tumors with an optimum set of features. Among thirteen studied features except one all differed significantly in three study classes. F-Ranking of features revealed highest discriminative potential of collagen III (initial region). F-Score arranged feature space dimension and application of Bhattacharyya distance gave rise to a feature set of lower dimension which can discriminate benign phyllodes and fibroadenoma effectively. The work definitely separated normal breast, fibroadenoma and benign phyllodes, through an optimal set of immuno-histochemical features which are not only useful to address diagnostic ambiguity of the tumors but also to spell about malignant potentiality. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Electron microscopical study of non-specific cholinesterase activity in simple lamellar corpuscles of glabrous skin from cat rhinarium: a histochemical evidence for the presence of collagenase-sensitive molecular forms and their secretion.

    Science.gov (United States)

    Dubový, P

    1989-01-01

    The distribution of nCHE activity was studied histochemically in simple lamellar corpuscles (SLCs) of glabrous skin from cat rhinarium. The Schwann cells forming myelin sheaths in preterminal part of SCLs exhibited no positive reaction for nCHE activity. Prevalent reaction product was localized extracellularly in the inne core enveloping terminal portion of unmyelinated sensory axon. A dot-like shaped reaction product was deposited in the basal lamina of the inner core cells and their cytoplasmic lamellae or was scattered in enlarged interlamellar spaces. Only small amount of fine end product was found to be associated with the plasma membrane of inner core lamellae. Fine reaction product for nCHE activity was consistently localized in perinuclear and rER cisternae and saccules of the Golgi apparatus of inner core cells. Some vesicles around rER and the Golgi apparatus, ones beneath the plasma membrane, and tubular-like cisternal profiles oriented towards the surface contained nCHE end product, as well. The intracellular and extracellular localization of nCHE reaction product suggests that this enzyme behaves in cat SLCs as a secreted rather than as an integral membrane protein. A large amount of dot-like reaction product in the interlamellar spaces disappeared if the skin sections were treated with collagenase before incubation in the medium for histochemical detection of nCHE activity. The decrease of nCHE end product in SLCs of the skin sections after collagenase digestion was corroborated by means of light microdensitometer and electrometrical measurement. The histochemical detection and electrometrical measurement revealed that the majority of the reaction product in the interlamellar spaces of inner core corresponds with the nCHE molecules sensitive to collagenase treatment and they are probably counted among asymmetrical molecular forms.

  14. Lysosomal enzyme activation in irradiated mammary tumors

    International Nuclear Information System (INIS)

    Clarke, C.; Wills, E.D.

    1976-01-01

    Lysosomal enzyme activity of C3H mouse mammary tumors was measured quantitatively by a histochemical method. Following whole-body doses of 3600 rad or less no changes were observed in the lysosomal enzyme activity for 12 hr after the irradiation, but very large increases in acid phosphatase and β-naphthylamidase activity were, however, observed 24 hr after irradiation. Significant increases in enzyme activity were detected 72 hr after a dose of 300 rad and the increases of enzyme activity were dose dependent over the range 300 to 900 rad. Testosterone (80 mg/kg) injected into mice 2 hr before irradiation (850 rad) caused a significant increase of lysosomal enzyme activity over and above that of the same dose of irradiation alone. If the tumor-bearing mice were given 95 percent oxygen/5 percent carbon dioxide to breathe for 8 min before irradiation the effect of 850 rad on lysosomal acid phosphatase was increased to 160 percent/that of the irradiation given alone. Activitation of lysosomal enzymes in mammary tumors is an important primary or secondary consequence of radiation

  15. Anatomical and histochemical analysis of vegetative organs of ...

    African Journals Online (AJOL)

    Samples of V. ferruginea vegetative organs were collected and submitted to the usual plant anatomy and histochemical techniques. The leaves are anfihipoestomática with anomocytic stomata; have tector and glandular trichomes that store essential oils. The stem has collateral-type vascular bundles arranged in a eustele ...

  16. Dietary fat level affecting histochemical radiosensitivity in dorsal aorta in rats

    International Nuclear Information System (INIS)

    Yousri, R.M.; Roushdy, H.M.; EL-Malkh, N.M.; Ashry, M.A.; Soliman, S.M.

    1988-01-01

    The present work has been conducted to investigate the effect of dietary fat status and/or cumulative whole body gamma radiation exposures up to 15 Gy the histochemical pattern of the dorsal aortas of male albino rats. Experimental animals were fed on either fat-rich or fat-free diet and the observations compared with those fed normal fat diet. The histochemical investigations has been confined to the concentration levels of mucopolysaccharide substance and total lipids. The dorsal aorta normal fat group showed higher content of PAS-positive material in the first two layers of the aorta wall in comparison with decreased amount of collagen fibers was shown in fat-rich group

  17. Comparison of new immunofluorescence method for detection of soy protein in meat products with immunohistochemical, histochemical, and ELISA methods

    Directory of Open Access Journals (Sweden)

    Michaela Petrášová

    2014-01-01

    Full Text Available Soy proteins are commonly used in the food industry thanks to their technological properties. However, soy is, along with cow’s milk, eggs, wheat, peanuts, tree nuts, fish, crustaceans, and molluscs, responsible for around 90% of food allergies, and is also one of the foodstuffs that can cause anaphylaxis. The aim of this work was to compare the immunofluorescence method for the detection of soy protein in meat products purchased from the retail market with other microscopic methods (immunohistochemical and histochemical, with the ELISA reference method and with the confirmatory results. Within the research, 127 meat products purchased in the retail network were examined using the immunofluorescence method used for the detection of soy protein. The method was compared to Enzyme-Linked ImmunoSorbent Assay (ELISA, immunohistochemical, and histochemical methods. According to McNemar’s test, non-compliance between the immunofluorescence method and immunohistochemical method was low. In addition, a significant difference between the fluorescence method and ELISA (P P < 0.01 was found. The immunofluorescence method was also compared with confirmatory results. According to McNemar’s test, non-compliance between the immunofluorescence method and confirmatory results was low. The results showed the possibilities of this new method to detect the content of soy protein in meat products.

  18. Pythiosis cutaneous in horses treated with triamcinolone acetonide. Part 2. Histological and histochemical description

    Directory of Open Access Journals (Sweden)

    José Cardona-Álvarez

    2017-09-01

    Full Text Available Objective. The study aimed to evaluate the histomorphometry tissue recovery process of the skin granuloma of skin pythiosis in horses treated with triamcinolone acetonide. Materials and methods. We conducted a descriptive study, not probabilistic in convenience animals with cutaneous pythiosis. 24 horses were used with cutaneous pythiosis, a group of 12 animals was administered 50 mg of intramuscular injection of triamcinolone acetonide (TG and the other group was not applied any treatment (CG. Are tissue biopsies performed for histological and histochemical evaluation and stained with hematoxylin eosin (HE, Gomori trichrome (GT, picrosirius red polarization (PR/P, Grocott methenamine silver (GMS and periodic acid-Schiff (PAS. Results. It is noted that in TG inflammation was gradually decreasing, as evidenced in decreased fibrin layer leukocyte, PMN and phenomena Splendore Hoepli, also in increased angiogenesis, epiteliogénesis, and increasing the overall amount of fibroblasts and collagen fibers, anyway in the progressive replacement of collagen type III to type I collagen at the end of the process, and that the presence of intralesional pseudohyphae of Pythium insidiosum reduces it to the second week. Neither of the animals in the CG showed improvement in histological and histochemical characteristics of pythiosis and maintained equal to the first day throughout the study. Conclusions. The use of triamcinolone acetonide is a good therapeutic alternative for the treatment of granulomatous pythiosis wounds in horses with 100% clinical recovery and demonstrated with histological and histochemical findings.

  19. Can cadaverous pollution from environmental lead misguide to false positive results in the histochemical determination of gunshot residues? Study on cadaveric skin samples.

    Science.gov (United States)

    Boracchi, Michele; Andreola, Salvatore; Collini, Federica; Gentile, Guendalina; Maciocco, Francesca; Maghin, Francesca; Zoja, Riccardo

    2017-08-01

    Histochemical determination of lead in gunshot residues (GSR) raises the question of possible environmental contamination by heavy metals. Authors assess the specificity of the Sodium Rhodizonate Test in the search of lead derived from environmental pollution. Sodium Rhodizonate Test and 5% HCl Sodium Rhodizonate test were applied to skin samples taken from two groups of victims, whose cause of death was not related to gunshot wounds: group A included 25 corpses found in open spaces after a long time; group B included 16 corpses exhumed after a period of 11 years. The use of these histochemical tests to skin samples from these two groups did not show metal debris histochemically similar to the lead present in GSR. These tests were confirmed to be specific in highlighting the GSR coming from gunshot, without being affected by the potential environmental contamination of the heavy metal pollutants, coming from air or soil. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Ahistological and histochemical study of the oesophagus and oesogaster of the Senegal sole, Solea senegalensis

    Directory of Open Access Journals (Sweden)

    JM Arellano

    2009-12-01

    Full Text Available A histological and histochemical study was performed in the buccal cavity and papillae, which were around the teeth, as well as in the oesophagus and oesogaster of the Senegal sole, Solea senegalensis adult specimens. The oesophagus and oesogaster were made up of four distinct layers: mucosa, submucosa, muscular and serous. Two morphological types of epithelial cells were distinguishable in the oesophageal mucosa: the more numerous type cells possessed an electron-dense cytoplasm, whereas the cytoplasm was electron-clear in the other cells. Mucussecreting cells were the dominant feature of the epithelium throughout the oesophagus. These goblet cells were filled with numerous mucous droplets of low electron-density. The oesophagus was devoid of taste buds.

  1. A quantitative histochemical study of D-amino acid oxidase activity in rat liver in relationship with feeding conditions

    NARCIS (Netherlands)

    Patel, H. R.; Frederiks, W. M.; Marx, F.; Best, A. J.; van Noorden, C. J.

    1991-01-01

    The histochemical method for the demonstration of D-amino acid oxidase activity in rat liver, based on the use of cerium ions and the diaminobenzidine-cobalt-hydrogen peroxide procedure, was improved by the application of unfixed cryostat sections and a semipermeable membrane interposed between

  2. Histochemical demonstration of creatine kinase activity using polyvinyl alcohol and auxiliary enzymes

    NARCIS (Netherlands)

    Frederiks, W. M.; Marx, F.; van Noorden, C. J.

    1987-01-01

    Creatine kinase activity (EC 2.7.3.2.) has been demonstrated in myocardium and skeletal muscle from rats by a method based on the incubation of cryostat sections with a polyvinyl alcohol-containing medium and the use of auxiliary enzymes. Hexokinase and glucose-6-phosphate dehydrogenase were spread

  3. Effect of localized intraoperative x-rays irradiation followed by intermittent external exposure on certain histochemical parameters related to pancreatic function

    International Nuclear Information System (INIS)

    Abdel-Azeem, M.G.

    2005-01-01

    The present study was carried out to evaluate the pancreatic enzyme activities in rabbits, whose splenic part of pancreas was exposed to local intraoperative radiation therapy (IORT) at level of 30 Gy X-rays followed by fractionated external radiation therapy (ERT) at a total dose of 40 Gy (2 Gy day after day) starting from the 15th day following the local intraoperative irradiation. The control pancreas was that received only external X-rays radiation without local irradiation. The exocrine pancreatic functions were assessed by determination of insulin hormone and enzyme activity of lipase as well as alkaline and acid phosphatases. After local X-rays irradiation on days 2 and 10 and after external X-rays irradiation on days 23 , 33 , 43 and 53, technovit-8100 plastic embedding (Kulzer and Heraeus) was used to prepare the cold blocks. The quantitative morphometric method was used to evaluate the histochemical pancreatic activity of the irradiated and control pancreas of each rabbit. Most of the studied parameters recorded non-significant changes as a result of the applied different levels of X-rays irradiation, which would give the chance to use this type of irradiation in pancreatic radiotherapy without any hazards to the pancreas

  4. Histochemical and ultrastructural study of an elastofibroma dorsi coexisting with a high grade spindle cell sarcoma

    Directory of Open Access Journals (Sweden)

    M Alberghini

    2009-06-01

    Full Text Available Elastofibroma dorsi is a pseudotumoral fibroproliferative lesion characterized by polymorphic fiber-like deposits of elastinophilic material. Several theories have been reported explaining the pathogenesis of elastofibroma. Recent cytogenetic studies have demonstrated chromosomal instability in elastofibromas, not normally observed in non-neoplastic tissues. These chromosomal defects are commonly observed in aggressive fibromatosis too. Such clinical observations suggest a multistage pathogenetic mechanism for the onset of elastofibroma. This study, using histochemical, immunohistochemical staining techniques, and ultrastructural examination, describes the detection of an otherwise typical elastofibroma contextual to a high grade sarcoma. Hence, the coexistence of elastofibroma and high-grade sarcoma may suggest a causal link between the two pathological entities. The results obtained suggest that the coexistence of the two pathological entities is conceivably coincidental.

  5. Electrophysiological, histochemical, and hormonal adaptation of rat muscle after prolonged hindlimb suspension

    Science.gov (United States)

    Kourtidou-Papadeli, Chrysoula; Kyparos, Antonios; Albani, Maria; Frossinis, Athanasios; Papadelis, Christos L.; Bamidis, Panagiotis; Vivas, Ana; Guiba-Tziampiri, Olympia

    2004-05-01

    The perspective of long-duration flights for future exploration, imply more research in the field of human adaptation. Previous studies in rat muscles hindlimb suspension (HLS), indicated muscle atrophy and a change of fibre composition from slow-to-fast twitch types. However, the contractile responses to long-term unloading is still unclear. Fifteen adult Wistar rats were studied in 45 and 70 days of muscle unweighting and soleus (SOL) muscle as well as extensor digitorum longus (EDL) were prepared for electrophysiological recordings (single, twitch, tetanic contraction and fatigue) and histochemical stainings. The loss of muscle mass observed was greater in the soleus muscle. The analysis of electrophysiological properties of both EDL and SOL showed significant main effects of group, of number of unweighting days and fatigue properties. Single contraction for soleus muscle remained unchanged but there was statistically significant difference for tetanic contraction and fatigue. Fatigue index showed a decrease for the control rats, but increase for the HLS rats. According to the histochemical findings there was a shift from oxidative to glycolytic metabolism during HLS. The data suggested that muscles atrophied, but they presented an adaptation pattern, while their endurance in fatigue was decreased.

  6. Histological and histochemical alterations in the kidney induced by lead

    International Nuclear Information System (INIS)

    Jarrar, Bashir M.

    2003-01-01

    Although lead intoxication is one of the most common forms of metal intoxication,the histochemichal alterations in renal tissues due to chronic lead exposure is limited and has not yet been well identified. A total of 60 male Wistar albino rats were exposed to lead acetate trihydrate( 0.0, 0.25, 0.5, 1.0 and 2% for 1 to 12 months) in drinking water to investigate the histological and histochemical alterations in renal tissues due to lead. Chronic exposure to the subtoxic doses of lead produced distinct progressive tubular, glomerular and interstitial damages. Tubular changes occured earlier than the glomerular and interstitial ones,and included anisokaryosis, nuclear pyknosis,karyomeglay, development of intranuclear cytoplasmic inclusions together with tubular dilation, necrosis,vacuolization, tubular hyperplasia and solid tubular adenoma. The glomrular alterations were mainly mesangial hypercellularity, segmental glomerulosclerosis, glomerular hyalinization and glomerular tuft alterations. The findings indicate that lead produces significant histological and histochemical changes in the kidney that lead to severe complications. (author)

  7. Effect of radon inhalations on certain oxyda-reductive enzymes in adrenols of white rats

    International Nuclear Information System (INIS)

    Robaczynski, J.; Kaplonska, J.; Lozinska, E.

    1974-01-01

    Histochemical investigations were carried out on adrenals of white rats after radon inhalations from inhalers in Swieradow-spa. Increased reactions of oxydo-reductive enzymes: NAD tetrazolium reductase, succinic dehydrogenase and glucose-6-phosphate dehydrogenase were observed in the adrenal cortex, particularly in the zona reticularis which was hypertrophied. Raised activity of oxydo-reductive enzymes in the cells of adrenal cortex evidences increased metabolism in these cells which may reflect increased production of hormones. Finding of stimulation of adrenocortical cells after radon inhalations is of essential importance for explanation of the biological mechanism of action of radon used in balneotherapy. (author)

  8. Histochemical and molecular evaluation of the prevalence of Leishmania spp. in hematophagous insects

    Directory of Open Access Journals (Sweden)

    Willian Marinho Dourado Coelho

    2016-06-01

    Full Text Available The prevalence study of Leishmania spp. in hematophagous insects captured from the environment in bat roosts and pigeon nests, or feeding their hosts (cattle, pigs, horses, dogs and humans in urban, peri-urban and rural areas, between 2012 and 2014. For this study, the amastigotes present in these insects were detected by histochemical and PCR techniques. Positive gene amplification for Leishmania was found in two horseflies of the species Tabanus importunus collected in the environment, and amastigote forms of Leishmania spp., as well as erythrocytes and leukocytes, were histochemically detected in one of that insect. The other analyzed insects were not positive by PCR our by direct parasitological examination. Only horseflies captured in urban and peri-urban areas were positive. During the collection, no phlebotomine sand flies were captured in rural areas far from the city limits. It can be concluded that the discovery of horseflies positive for Leishmania spp. in urban and peri-urban areas indicates the likelihood that urban areas and their surroundings provide vector parasites with an environment suitable for the spread and consequent perpetuation of the biological cycle of this protozoan.

  9. The effect of hyperthermia and radiation on lysosomal enzyme activity of mouse mammary tumours

    International Nuclear Information System (INIS)

    Barratt, G.M.; Wills, E.D.

    1979-01-01

    The effects of hyperthermia and radiation have been studied on the acid phosphatase and β-glucuronidase activities in lysosomes of C3H mice mammary tumours and of the spleen. Quantitative histochemical methods have been used. Hyperthermic treatment of both spontaneous and transplanted tumours caused an increase in the activity of both acid phosphatase and β-glucuronase when measured immediately after treatment, but the activities returned to normal after 24 hours. In contrast a radiation dose of 3500 rad did not cause an increase in activity of either enzyme immediately, but a large activation was observed after 24 hr. Combination of hyperthermic and radiation treatment caused increases in enzyme activities which were dependent on the time after treatment. Hyperthermic treatment of the lower body of mice bearing tumours also caused activation of lysosomal enzymes in the spleen. This may be hormone mediated. It is considered that the increased lysosomal enzyme activity observed after hyperthermia may be a consequence of increased permeability of the lysosomal membrane caused by hyperthermia. (author)

  10. Micromorphology and histochemical traits of staminal osmophores in Asphodelus aestivus Brot. flower

    OpenAIRE

    Elżbieta Weryszko-Chmielewska; Mirosława Chwil; Thomas Sawidis

    2012-01-01

    The conducted studies pertained to micromorphology of the surface of epidermis cells and histological traits of staminal filaments of Asphodelus aestivus Brot. flowers. The structure of the filaments was analyzed in a light microscope (LM) using various histochemical techniques. The morphology of the surface of the epidermis of filaments was observed in scanning electron microscope (SEM). Filaments Asphodelus aestivus accrete together with the basal part of the abaxial surface with the leaves...

  11. Cytoplasmic male sterility in Petunia hybrida : a structural and histochemical analysis

    NARCIS (Netherlands)

    Bino, R.J.

    1986-01-01

    This thesis presents an analysis of the structural and histochemical aspects of cytoplasmic male sterility (cms) in Petuniahybrida . In petunia and in other crops, cms is the most commonly used tool for hybrid seed production. Application of the trait

  12. Palatal shelf epithelium: a morphologic and histochemical study in X-irradiated and normal mice

    International Nuclear Information System (INIS)

    Gartner, L.P.; Hiatt, J.L.; Provenza, D.V.

    1978-01-01

    The palatal shelf epithelium of normal and irradiated mice was examined morphologically and histochemically, utilizing the periodic acid-Schiff (PAS) technique for the demonstration of the basement membrane and the Nitro BT method for succinate dehydrogenase activity in order to demonstrate the metabolic competence of its cells. The 'programmed cell death theory' was not supported by the present investigation, since the cells of the medial ridge epithelium retained their structural and metabolic integrity even subsequent to the formation of cell nests. Additionally, the medial ridge epithelium of mice with radiation-induced cleft palates demonstrated normal structural and metabolic integrity long past the prospective time of fusion. (author)

  13. Methylmercury intoxication and histochemical demonstration of NADPH-diaphorase activity in the striate cortex of adult cats

    Directory of Open Access Journals (Sweden)

    R.B. Oliveira

    1998-09-01

    Full Text Available The effects of methylmercury (MeHg on histochemical demonstration of the NADPH-diaphorase (NADPH-d activity in the striate cortex were studied in 4 adult cats. Two animals were used as control. The contaminated animals received 50 ml milk containing 0.42 µg MeHg and 100 g fish containing 0.03 µg MeHg daily for 2 months. The level of MeHg in area 17 of intoxicated animals was 3.2 µg/g wet weight brain tissue. Two cats were perfused 24 h after the last dose (group 1 and the other animals were perfused 6 months later (group 2. After microtomy, sections were processed for NADPHd histochemistry procedures using the malic enzyme method. Dendritic branch counts were performed from camera lucida drawings for control and intoxicated animals (N = 80. Average, standard deviation and Student t-test were calculated for each data group. The concentrations of mercury (Hg in milk, fish and brain tissue were measured by acid digestion of samples, followed by reduction of total Hg in the digested sample to metallic Hg using stannous chloride followed by atomic fluorescence analysis. Only group 2 revealed a reduction of the neuropil enzyme activity and morphometric analysis showed a reduction in dendritic field area and in the number of distal dendrite branches of the NADPHd neurons in the white matter (P<0.05. These results suggest that NADPHd neurons in the white matter are more vulnerable to the long-term effects of MeHg than NADPHd neurons in the gray matter.

  14. Histochemical alterations in colorectal carcinoma and adenoma in Egyptian patients

    Directory of Open Access Journals (Sweden)

    Saber A Sakr

    2016-01-01

    Full Text Available Objective: To evaluate the histochemical alterations in DNA and total carbohydrates, in colorectal cancer cells. Methods: This study was carried out on 48 colorectal carcinoma and 10 adenoma specimens. Hematoxylin and Eosin staining was carried out for histopathological examination to confirm the diagnosis and to evaluate the histopathological characteristics of tumor. Histologic grade and pathologic stage was assessed according to TNM staging system. Staging was also assessed according to original Dukes’ staging system. DNA was demonstrated by Feulgen method and carbohydrates were demonstrated by periodic acid Schiff’s reaction. Results: Adenoma cases showed that the cells lining the glands of the polyp have more crowded, irregular and darker nuclei (hyperchromatic, anisonucleosis, abnormal mitotic figures with prominent nucleoli and variability in the size and shape of nuclei. Colorectal carcinoma cases showed a condensation and reduction in the size of a cell nucleus associated with hyperchromatosis, pyknotic nuclei, abnormal mitotic figures, anisonucleosis, irregular nuclear membrane and inequality in the size of the nuclei (Pleomorphosis. There was a statistical significant differences between adenoma and carcinoma regarding number of mitotic cells (P = 0.03 that was in favour of malignant group. Adenoma and colorectal carcinoma cases showed periodic acid Schiff’s reactivity with different degree. Conclusions: These histochemical alterations can be so characteristic of a given tumor type and stage that they are used in cancer diagnosis and might also be related to the altered functional properties of cancer cells.

  15. Histochemical investigation of Cochlospermum regium (Schrank) Pilg. leaves and chemical composition of its essential oil.

    Science.gov (United States)

    Inácio, Marielle Cascaes; Paz, Tiago Antunes; Bertoni, Bianca Waléria; Vieira, Maria Aparecida Ribeiro; Marques, Márcia Ortiz Mayo; Pereira, Ana Maria Soares

    2014-01-01

    Essential oil from Cochlospermum regium (Schrank) Pilg. leaves (CR-EO) has been extracted by hydrodistillation; we analysed the CR-EO by gas chromatography coupled with mass spectrometry. We also conducted histochemical analysis on cross-sections of the central vein of young and adult leaves. A total of 32 compounds were qualitatively and quantitatively analysed, which represented 94.87% of the total CR-EO oil content. The CR-EO basically consisted of sesquiterpenes (96.87%); its main component was β-copaen-4-α-ol (18.73%), followed by viridiflorol (12.67%). The histochemical analyses identified the main classes of compounds present in both young and adult leaves.

  16. Morphological and histochemical study of cleft palate induced in CD-1 mice by whole body x-radiation

    International Nuclear Information System (INIS)

    Lewis, C.E.

    1977-01-01

    Palatogenesis in CD-1 mice exposed to 300 or 400 rads of x-radiation in utero was compared with palate development of unirradiated fetuses to determine whether any correlation exists between time of irradiation (days nine through twelve) and the incidence of morphological or histochemical variations in fetal palate tissues. Data accumulated indicate that although x-radiation reduces fetal weight and crown-rump length and retards palate closure, growth, ossification and SDH activity, fetuses exhibit some recovery from radiation damage

  17. Histopathological and histochemical changes in the liver of Bagrus bayad caused by environmental pollution.

    Science.gov (United States)

    Gaber, Hanan S; Ibrahim, Seham A; El-Kasheif, Midhat A

    2015-09-01

    This study focused on two areas (Abu-Zaabal and El-Tal El-Kabir) of the Ismailia canal. The samples represented the effect of the factories' effluent discharge onto the canal. Physical characteristics (water temperature and pH) and chemical characteristics (total hardness, dissolved oxygen, biological oxygen demand and chemical oxygen demand) were measured to identify the water quality in the two areas of the Ismailia canal. These measurements showed slight variations between the two stations. Additionally, the histological and histochemical analyses in the liver of Bagrus bayad fish samples were done. Histological studies of liver showed more severe degeneration in the fish samples of El-Tal El-Kabir station. Histochemical studies on protein and glycogen contents in the liver of B. bayad showed a progressive decrease in their staining intensity to bromophenol blue and periodic acid Schiff at two stations. This study, therefore, concludes that Ismailia canal water (Abu-Zaabal and El-Tall El-Kabir) stations create metabolic crisis and impairment in fish liver. The depletion in the levels of protein and glycogen points leads to the exhaustion of cell energy that is of high demand for fish during stressful conditions. Therefore, it is imperative for the authorities concerned to ensure that treated effluent discharge comply with acceptable standards to save our environment from destruction. © The Author(s) 2013.

  18. Structural and histochemical considerations of parotid gland from adult rats (Holtzmann) submitted to x-rays exposure

    International Nuclear Information System (INIS)

    Sposto, M.R.

    1988-01-01

    A histomorphological and histochemical study of the parotid gland of adult rats was carried out after subjecting the animals to a single X-ray irradiation dose of 900 R directed to the cervical region. The samples for the histological analysis were obtained at 2, 7, 15, 21, 30 and 45 days after radiation through desiccation and removal of the glands. The results showed clearly that the parotid gland is quite sensitive to X-ray irradiation with the serous acinar cells presenting heavier injuries than the mucous ones. A maximum in the deleterial action of the irradiation was detected at 15 days during the observation period. A comparative analysis of the glandular ducts showed that both of the types intercalated and striated were damaged, with the last presenting severe alterations in morphology and volume. By interpretation of the histochemical results it was concluded that a reduction in protein metabolism of the parotid gland occurred as a consequence of the X-ray irradiation. (author)

  19. Histochemical characterization of human osteochondral tissue: comparison between healthy cartilage, arthrotic tissues, and cartilage defect treated with MACI technique

    Directory of Open Access Journals (Sweden)

    F. Tessarolo

    2011-01-01

    Full Text Available Matrix-induced sutologous chondrocytes implantation (MACI is a promising technique for the treatment of articular cartilage lesions, but long time outcome have to be established. We developed and optimized specific techniques of histochemical staining to characterize healthy and pathologic osteochondral tissue. Seven different staining protocols were applied to assess tissue architecture, cells morphology, proteoglycan content, and collagen fibers distribution. Potentialities of histochemical staining and histomorphology of biopsies from second look arthroscopy will be presented.

  20. Immuno-histochemical features of the structure of foetuses' ovarian from the mothers with pregnancy complications

    Directory of Open Access Journals (Sweden)

    Larisa Kupriianova

    2017-02-01

    Kharkiv National Medical University, Kharkov, Ukraine   Abstract As a material of our research, we took into account foetuses' ovarian at the gestation term from 21 to 42 weeks; and, as a result, all types of material we divided into few groups: foetuses from healthy mothers; foetuses from mothers with pre-eclampsia complications of pregnancy of different stages; foetuses from mothers with pregnancy's complications as a chronical infection. Research methods: organomethrical, histochemical, immuno-histochemical, statistical. As a result of the complex research, in foetuses' ovarian from mothers with pregnancy complications of different types, we can see reducing of indicators of structural and functional activity of organs, increasing of apoptotic index; increasing of endothelin-1 production; decreasing of hormones production. Key words: fetus, pregnancy, pre-eclampsia; infection, ovary.

  1. Glycoconjugate sugar residues in the chick embryo developing lung: a lectin histochemical study.

    Science.gov (United States)

    Gheri, G; Sgambati, E; Bryk, S G

    2000-03-01

    A lectin histochemical study was performed to investigate the distribution and changes of the oligosaccharidic component of the glycoconjugates in the lung of chick embryos, of 1-day-old chick, and of the adult animal. For this purpose, a battery of seven horseradish peroxidase-conjugated lectins (PNA, SBA, DBA, WGA, Con A, LTA, and UEA I) were employed. During the first phase of parabronchi and atria formation, D-galactose-(beta1-->3)-N-acetyl-D-galactosamine, beta-N-acetyl-D-galactosamine, D-glucosamine, alpha-D-mannose, and sialic acid, present at the level of the surface and of cytoplasmic granules of the lining epithelial cells, seem to play a role in regulating morphogenetic phenomena. In the subsequent phases, the parabronchial lumen and the atrial cavities were characterized by the presence of lectin-reactive material rich in terminal D-galactose-(beta1-->3)-N-acetyl-D-galactosamine, beta-N-acetyl-D-galactosamine, D-glucosamine and alpha-D-mannose. From day 18 onwards and immediately after hatching, the free border of the cells lining the air capillaries was characterized by the presence of beta-N-acetyl-D-galactosamine and alpha-D-mannose. The appearance of these sugar residues was concomitant with the beginning of respiratory activity. Copyright 2000 Wiley-Liss, Inc.

  2. Skeletal muscle injury induced by a pneumatic tourniquet: an enzyme- and immunohistochemical study in rabbits.

    Science.gov (United States)

    Pedowitz, R A; Fridén, J; Thornell, L E

    1992-03-01

    The pathophysiology of skeletal muscle injury induced by compression beneath pneumatic tourniquets is poorly understood. Tourniquet hemostasis was induced in rabbit hindlimbs for 2 hr with a cuff inflation pressure of either 125 mm Hg (n = 5) or 350 mm Hg (n = 5). Skeletal muscle biopsies, taken 2 days later from tissue beneath and distal to the tourniquet, were frozen and analyzed using enzyme- and immunohistochemical techniques. In the 350 mm Hg tourniquet group, four of 10 thigh muscle samples demonstrated significant regional necrosis (mean 37.3% of the total cross-sectional area). Regional necrosis was not observed in thigh muscles of the 125 mm Hg tourniquet group or in any of the ischemic leg muscles. A topographic pattern of necrosis consistent with the arterial distribution of skeletal muscle suggested pathogenic events during the reperfusion period, such as granulocyte-mediated superoxide radical formation. Extremely large and rounded fibers (histochemically identified as Type IIB fibers) were observed in compressed thigh muscles, indicating differential fiber sensitivity to tourniquet compression and ischemia. The present study demonstrated significant skeletal muscle necrosis after a 2 hr tourniquet applied at a clinically relevant cuff inflation pressure. Recent studies of systemic changes associated with limb "ischemia" should be reassessed in consideration of the confounding effects of tissue compression induced beneath pneumatic tourniquets.

  3. Histomorphological and mucin histochemical study of the alimentary canal of pangas catfish, Pangasius pangasius (Hamilton 1822

    Directory of Open Access Journals (Sweden)

    Javd Sadeghinezhad

    2017-06-01

    Full Text Available The present study describes the histological and mucin histochemical properties of the alimentary canal (AC of the pangas catfish, Pangasius pangasius. The results revealed that the mucosa of the oesophagus was lined by a stratified epithelium containing chloride cells and taste buds which suggested mechanic, gustatory and physiologic roles of the oesophagus in this species. The stomach mucosa was lined by a simple columnar epithelium. The lamina propria-submucosa in cardiac and fundic stomach contained gastric glands. The pyloric stomach had the thickest muscularis layer among all the parts of the AC. The villi showed the maximum height and width in the middle intestine. The tunica muscularis and serosa showed the thinnest thickness among all parts of AC. The mucin histochemistry showed that the goblet cells of oesophagus and intestine contained both neutral and acidic with carboxylated and sulfated mucins and there was not acidic mucins in epithelial cells of the stomach.

  4. Histochemical and functional parameters in Nordic combination athletes.

    Science.gov (United States)

    Matolín, S; Vaverka, F; Lunák, J; Novák, J; Horák, V; Krejcí, P

    1994-01-01

    Bioptic samples from the vastus lateralis muscle were analyzed in a group of Czechoslovak representatives in the Nordic combination (ski-jumping and 15 km cross-country skiing). The distribution of individual muscle fibre types (FG, FOG and SO) was detected and correlated with values obtained by motor and functional performance tests. Histochemical analysis of the bioptic samples revealed a considerably heterogeneous distribution of muscle fibre types in the group studied. No typical profilation for this sport discipline was found. Weak correlation between the proportion of fast muscle fibres and explosive strength parameters was ascertained. The correlation between the proportion of slow muscle fibres and the capacity of O2 utilization (VO2max) was statistically significant. Strong correlation between the proportion of fast twitch fibres and relative maximal strength of knee extensors (N/kg) was disclosed. A non-linear relation between the area of fast twitch fibres and vigour of take-off was found.

  5. Microscopic and histochemical manifestations of hyaline cartilage dynamics.

    Science.gov (United States)

    Malinin, G I; Malinin, T I

    1999-01-01

    Structure and function of hyaline cartilages has been the focus of many correlative studies for over a hundred years. Much of what is known regarding dynamics and function of cartilage constituents has been derived or inferred from biochemical and electron microscopic investigations. Here we show that in conjunction with ultrastructural, and high-magnification transmission light and polarization microscopy, the well-developed histochemical methods are indispensable for the analysis of cartilage dynamics. Microscopically demonstrable aspects of cartilage dynamics include, but are not limited to, formation of the intracellular liquid crystals, phase transitions of the extracellular matrix and tubular connections between chondrocytes. The role of the interchondrocytic liquid crystals is considered in terms of the tensegrity hypothesis and non-apoptotic cell death. Phase transitions of the extracellular matrix are discussed in terms of self-alignment of chondrons, matrix guidance pathways and cartilage growth in the absence of mitosis. The possible role of nonenzymatic glycation reactions in cartilage dynamics is also reviewed.

  6. Histological and histochemical studies on liver of rat subjected to synergistic effect of natural and synthetic food colorants and/or gamma irradiation

    International Nuclear Information System (INIS)

    Soliman, O.; Hafez, M. N.; Abd El Maguid, A.

    2007-01-01

    The present work has been carried out to detect some histological and histochemical changes in the liver of albino rats after oral administration of a mixture of the synthetic food colorants tartrazine and brilliant blue and/ or gamma-irradiation (5 Gy). The possible ameliorative effect of the natural food colorant beta-carotene (30 mg/ kg body wt) orally administered with the synthetic food colorants tartrazine and brilliant blue and irradiation was evaluated. Rats were divided into five groups: 1- Control group. 2- Group received a food colorant mixture of tartrazine and brilliant blue (100 mg/ kg body wt). 3- Group received gamma-irradiation at 5 Gy. 4-Animals received the food colorant mixture for 2 weeks and were irradiated. 5- Animals received beta-carotene (30 mg/ kg body wt) with the food colorant mixture for 2 weeks and were then irradiated (5 Gy). Administration of tartrazine and brilliant blue caused histopathological and histochemical changes in the liver of rat manifested by haemorrhage, vacuolar degeneration of hepatocytes, dilatation of blood sinusoids, scattered necrotic areas and a decrease in the mucopolysaccharides content. The radiation caused infiltration of inflammatory cells in the portal area, necrosis with pyknosis and karyolysis of nuclei and a decrease in the mucopolysaccharide content of hepatic cells 1 and 3 days post-irradiation. The present work also showed that the natural food colorant beta-carotene reduced the toxicity of the synthetic food colorants tartrazine and brilliant blue and gamma-irradiation when the natural pigment was given together with the synthetic dyes used as food additives. In conclusion, synthetic food colours and/ or radiation induced histopathological and histochemical disturbances in rats. On the other hand, administration of the natural food colorant beta-carotene had a significant protective role against the damaging effects induced by these synthetic colours mixture

  7. Quantification of histochemical stains using whole slide imaging: development of a method and demonstration of its usefulness in laboratory quality control.

    Science.gov (United States)

    Gray, Allan; Wright, Alex; Jackson, Pete; Hale, Mike; Treanor, Darren

    2015-03-01

    Histochemical staining of tissue is a fundamental technique in tissue diagnosis and research, but it suffers from significant variability. Efforts to address this include laboratory quality controls and quality assurance schemes, but these rely on subjective interpretation of stain quality, are laborious and have low reproducibility. We aimed (1) to develop a method for histochemical stain quantification using whole slide imaging and image analysis and (2) to demonstrate its usefulness in measuring staining variation. A method to quantify the individual stain components of histochemical stains on virtual slides was developed. It was evaluated for repeatability and reproducibility, then applied to control sections of an appendix to quantify H&E staining (H/E intensities and H:E ratio) between automated staining machines and to measure differences between six regional diagnostic laboratories. The method was validated with laboratories from 0.57 to 0.89. A simple method using whole slide imaging can be used to quantify and compare histochemical staining. This method could be deployed in routine quality assurance and quality control. Work is needed on whole slide imaging devices to improve reproducibility. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  8. Histo-chemical and biochemical analysis reveals association of er1 mediated powdery mildew resistance and redox balance in pea.

    Science.gov (United States)

    Mohapatra, Chinmayee; Chand, Ramesh; Navathe, Sudhir; Sharma, Sandeep

    2016-09-01

    Powdery mildew caused by Erysiphe pisi is one of the important diseases responsible for heavy yield losses in pea crop worldwide. The most effective method of controlling the disease is the use of resistant varieties. The resistance to powdery mildew in pea is recessive and governed by a single gene er1. The objective of present study is to investigate if er1 mediated powdery mildew resistance is associated with changes in the redox status of the pea plant. 16 pea genotypes were screened for powdery mildew resistance in field condition for two years and, also, analyzed for the presence/absence of er1 gene. Histochemical analysis with DAB and NBT staining indicates accumulation of reactive oxygen species (ROS) in surrounding area of powdery mildew infection which was higher in susceptible genotypes as compared to resistant genotypes. A biochemical study revealed that the activity of superoxide dismutase (SOD) and catalase, enzymes involved in scavenging ROS, was increased in, both, resistant and susceptible genotypes after powdery mildew infection. However, both enzymes level was always higher in resistant than susceptible genotypes throughout time course of infection. Moreover, irrespective of any treatment, the total phenol (TP) and malondialdehyde (MDA) content was significantly high and low in resistant genotypes, respectively. The powdery mildew infection elevated the MDA content but decreased the total phenol in pea genotypes. Statistical analysis showed a strong positive correlation between AUDPC and MDA; however, a negative correlation was observed between AUDPC and SOD, CAT and TP. Heritability of antioxidant was also high. The study identified few novel genotypes resistant to powdery mildew infection that carried the er1 gene and provided further clue that er1 mediated defense response utilizes antioxidant machinery to confer powdery mildew resistance in pea. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  9. Recombinant adenylate kinase 3 from liver fluke Clonorchis sinensis for histochemical analysis and serodiagnosis of clonorchiasis.

    Science.gov (United States)

    Kwon, Soon Bin; Kim, Paul; Woo, Hae Sun; Kim, Tae Yun; Kim, Ju Yeong; Lee, Hye Min; Jang, Yun Soo; Kim, Eun-Min; Yong, Tai-Soon; Seong, Baik Lin

    2018-03-27

    Due to the lack of an effective prophylactic intervention and diagnosis, human liver fluke Clonorchis sinensis continues to afflict a large human population, causing a chronic inflammatory bile duct disease. With an aim to identify target antigens for sensitive serodiagnosis, adenylate kinase 3 of C. sinensis (CsAK3) was successfully expressed in soluble form in Escherichia coli by fusion to an RNA-interacting domain derived from human Lys-tRNA synthetase and purified by Ni2+-affinity chromatography. Anti-CsAK3 serum was raised by immunization of mice, and Western blotting confirmed that CsAK3 was expressed in adult-stage C. sinensis. Histochemical analysis showed that CsAK3 was localized to the subtegumental tissue of C. sinensis and was excreted into the bile duct of the host. When tested against sera from various parasite-infected patients by enzyme-linked immunosorbent assay, the recombinant CsAK3 elicited a specific response to C. sinensis-infected sera. The results suggest that CsAK3, either alone or in combination with other antigens, could be used for improving the clinical diagnosis of clonorchiasis.

  10. Detection of human filarial parasite Brugia malayi in dogs by histochemical staining and molecular techniques.

    Science.gov (United States)

    Ambily, V R; Pillai, Usha Narayana; Arun, R; Pramod, S; Jayakumar, K M

    2011-09-27

    Human filariasis caused by Brugia malayi is still a public health problem in many countries of Asia including India, Indonesia, Malaysia and Thailand. The World Health Organization (WHO) has targeted to eliminate filariasis by the year 2020 by Mass annual single dose Diethylcarbamazine Administration (MDA). Results of the MDA programme after the first phase was less satisfactory than expected. Malayan filariasis caused by B. malayi is endemic in the south of Thailand where domestic cat serves as the major reservoir host. There is no report about the occurrence of B. malayi in dogs. The present work was carried out to find out the incidence of microfilariasis in dogs and also to detect the presence of human filarial infection in dogs, if any. One hundred dogs above 6 months of age presented to the veterinary college Hospital, Mannuthy, Kerala, with clinical signs suggestive of microfilariasis - fever, anorexia, conjunctivitis, limb and scrotal oedema - were screened for microfilariae by wet film examination. Positive cases were subjected to Giemsa staining, histochemical staining and molecular techniques. Results of the study showed that 80% of dogs had microfilariasis; out of which 20% had sheathed microfilaria. Giemsa and histochemical staining character, PCR and sequencing confirmed it as B. malayi. High prevalence of B. malayi in dogs in this study emphasized the possible role of dogs in transmission of human filariasis. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Histochemical localization of cholinesterase activity in the dental epithelium of guinea pig teeth.

    Science.gov (United States)

    Jayawardena, C K; Takano, Y

    2004-07-01

    Cholinesterase is known for its remarkable diversity in distribution and function. An association of this enzyme with proliferative and morpho-differentiating tissues has been reported in several species. Here we report on the first evidence of the presence of cholinesterase in the enamel organ of continuously erupting incisors and molars of the guinea pig. Frozen sections of the incisors and molars of the guinea pig were incubated for histochemical demonstration of cholinesterase activity by means of the thiocholine method as described by Karnovsky and Root. The cholinesterase activity was observed in several types of cells of the dental epithelium; cells forming the basal portion of the enamel organ, outer enamel epithelium and maturation stage ameloblasts of both the incisors and molars. In the crown analogue side, the outer enamel epithelial cells gained strong reactions for cholinesterase and maintained the reaction throughout the secretory and maturation stages of amelogenesis. In contrast, cholinesterase reactions were lacking in the inner enamel epithelium, pre-ameloblasts, and secretory ameloblasts. In the early stage of enamel maturation, ameloblasts began to show positive reactions for cholinesterase, which was upregulated in the incisal direction. Although both tooth types showed similar reactive patterns for cholinesterase at the growing ends, maturation ameloblasts depicted a different pattern of staining displaying the reactions only sporadically in molars. These data indicate the role of cholinesterase in the enamel organ in tooth morphogenesis and function of guinea pig teeth. Copyright 2004 Springer-Verlag

  12. A lectin histochemical study on carbohydrate moieties of the gonadotropin-like substance in the epithelial cells of Hatschek's pit of Branchiostoma belcheri

    Science.gov (United States)

    Fang, Y. Q.; Welsch, U.

    1997-03-01

    The present light microscopic lectin, histochemical study suggests for the first time that the vertebrate gonadotropin-like substance in the basal part of the epithelial cells of Hatschek's pit is a sialic acid-containing glycoprotein. The binding intensity of the epithelial cells in Hatschek's pit to 6 lectins ( Limulus polyphemus agglutinin (LPA), Wheat germ agglutinin (WGA), Helix pomatia agglutinin (HPA), Concanavalin A (Con A), Ulex europaeus agglutinin I (UEA I) and Ricinus communis agglutinin I (RCA I)) indicate that the carbohydrate composition of the gonadotrophic glycoprotein is similar to that of mammals and fish, and that N-acetyl-D-galactosamine, sialic acid, glucosamine, D-mannose and L-fucose are components of the carbohydrate portion.

  13. Histological, surface ultrastructural, and histochemical study of the stomach of red piranha, Pygocentrus nattereri (Kner

    Directory of Open Access Journals (Sweden)

    Ghosh Saroj Kumar

    2015-12-01

    Full Text Available The structural characterization and function of the stomach in the omnivore Pygocentrus nattereri were described using light and scanning electron microscopy. The sac-like stomach was morphologically divided into the cardiac and pyloric regions. The histological structure of the stomach consisted of four layers of the mucosa, submucosa, muscularis, and serosa. The superficial epithelium of the cardiac stomach was lined with columnar epithelial cells and the glandular epithelium contained numerous gastric glands. Gastric glands were completely absent in the pyloric portion. The mucosal surface of the stomach was a meshwork of various folds, provided with oval or rounded columnar epithelial cells which were densely packed with short, stubby microvilli. The occasional presence of conspicuous gastric pits was surrounded by epithelial cells. The localization and chemical nature of acid and neutral mucins in the various cells of the stomach was studied by employing combined the Alcian Blue-Periodic Acid Schiff (AB-PAS technique. The deposition of glycogen was detected in the gastric glands as well as in the epithelial lining of the stomach. The utmost reactions for protein and tryptophan were recorded in the gastric glands of mucosa. The cellular organization and histochemical characterization of the stomach are discussed in relation to the feeding and digestion of the fish concerned.

  14. Histochemical study of reaction of the nucleus supraopticus of rat brain to irradiation with 500 Gy

    International Nuclear Information System (INIS)

    Dosoudilova, M.; Kamarad, V.

    1987-01-01

    The activities were described of some enzymes in nucleus supraopticus of the rat brain at an early interval (5 min) after gamma irradiation with 500 Gy, at a dose rate of 6.9 Gy per minute. The study was performed using cryostat sections. The activities of the following enzymes were shown: alkaline phosphatase, acid phosphatase, ATP-splitting enzyme, thiaminepyrophosphatase, butyrylcholinesterase, acetylcholinesterase, glycero-3-phosphate-dehydrogenase, succinate dehydrogenase, acid nonspecific esterase, and beta glucuronidase. After irradiation, increased activities of acid phosphatase, thiaminepyrophosphatase, and acetylcholinesterase was observed in perikarya of magnocelullar neurons of the nucleus, whereas the activities of other enzymes were weak when compared to controls. A significant decrease in the activity of acidic nonspecific esterase was found. In contrast to the controls, blood capillaries showed increased activities of ATP-splitting enzyme, butyrylcholinesterase, thiaminepyrophosphatase. The activities of alkaline phosphatase and acid phosphatase were not changed. No activity of other enzymes was observed in that site. (author). 13 refs

  15. Molecular extinction coefficients of lead sulfide and polymerized diaminobenzidine as final reaction products of histochemical phosphatase reactions

    NARCIS (Netherlands)

    van Noorden, C. J.; Jonges, G. N.

    1992-01-01

    Molar extinction coefficients of precipitated lead sulfide (PbS) and polymerized diaminobenzidine (polyDAB) have been determined at wavelengths of 450 nm and 480 nm, respectively, for quantitative histochemical analysis of phosphatase reactions. These values are essential for the conversion of

  16. Case report. Sclerosing peritoneal mesothelioma in a dog: histopathological, histochemical and immunohistochemical investigations

    Directory of Open Access Journals (Sweden)

    Anna Rita D'Angelo

    2014-12-01

    Full Text Available Mesotheliomas are rare neoplasm affecting on rare occasions both animals and humans and which arise from the mesothelial cells lining the coelomic cavities. We report herein the histopathological, histochemical and immunohistochemical findings in a dog affected by sclerosing peritoneal mesothelioma, a rare variant of canine mesothelioma, and submitted to laparotomy in December 2012 (Teramo, Italy. Our data confirm that mesothelioma still represents a diagnostic challenge and that immunohistochemistry can be extremely useful as supportive diagnostic technique.

  17. Influence of long-term hyper-gravity on the reactivity of succinic acid dehydrogenase and NADPH-diaphorase in the central nervous system of fish: a histochemical study

    Science.gov (United States)

    Anken, R. H.; Rahmann, H.

    In the course of a densitometric evaluation, the histochemically demonstrated reactivity of succinic acid dehydrogenase (SDH) and of NADPH-diaphorase (NADPHD) was determined in different brain nuclei of two teleost fish (cichlid fish Oreochromis mossambicus, swordtail fish Xiphophorus helleri), which had been kept under 3g hyper-gravity for 8 days. SDH was chosen since it is a rate limiting enzyme of the Krebs cycle and therefore it is regarded as a marker for metabolic and neuronal activity. NADPHD reactivity reflects the activity of nitric oxide synthase. Nitric oxide (NO) is a gaseous intercellular messenger that has been suggested to play a major role in several different in vivo models of neuronal plasticity including learning. Within particular vestibulum-connected brain centers, significant effects of hyper-gravity were obtained, e.g., in the magnocellular nucleus, a primary vestibular relay ganglion of the brain stem octavolateralis area, in the superior rectus subdivision of the oculomotoric nucleus and within cerebellar eurydendroid cells, which in teleosts possibly resemble the deep cerebellar nucleus of higher vertebrates. Non-vestibulum related nuclei did not respond to hypergravity in a significant way. The effect of hyper-gravity found was much less distinct in adult animals as compared to the circumstances seen in larval fish (Anken et al., Adv. Space Res. 17, 1996), possibly due to a development correlated loss of neuronal plasticity.

  18. Histochemical Structure of Stomach (Proventriculus and Gizzard in Some Bird Species

    Directory of Open Access Journals (Sweden)

    Emel DEMİRBAĞ

    2015-09-01

    Full Text Available Stomach samples (proventriculus and gizzard of sparrow hawk (Accipiter nisus, crow (Corvus corone and sparrow (Passer domesticus were investigated in this study. In histochemical investigations, strong sulfated mucins were not determined in compound glands of proventriculus, but a little reaction to AB (pH 0.5 in compound glands was observed in proventriculus of sparrow hawk and crow. While weak AB (pH 1.0 (+ character was found in sparrow gizzard, it was found as dense in superficial glands of sparrow hawk. However, it was not observed in crow gizzard. While AF (+ character (sulfated mucins was detected as dense in epithelium and as weak in glands of gizzard of sparrow hawk, this character was not observed in glands of gizzards of crow and sparrow. Any reactivity to Periodic Acid-Shiff (PAS staining was not observed in both epithelium and glands of sparrow proventriculus

  19. [Histochemical detection of glycoproteins and glycosaminoglycans in the respiratory mucosa of albino rats during estrous cycle, pregnancy and puerperium].

    Science.gov (United States)

    Pontes, P A; Simões, M J; Merzel, J

    1989-11-01

    In this work we attempted to detect, with histochemical methods, the possible modifications in the mucus of the respiratory mucosa of albino female rats during estral cycle, pregnancy and puerperium. Based on its results, it was possible to conclude that: a--There were no modifications in the nature of the epithelial and supraepithelial mucus during the studied periods: b--The Alcian Blue staining from lamina propria is absent during pregnancy and present during puerperium.

  20. Carbohydrate specificity of lectin, purified from the fruiting bodies of Mycena pura /Fr./ Kumm. and its use in histochemical investigation

    Directory of Open Access Journals (Sweden)

    Ambarova N. O.

    2009-12-01

    Full Text Available Aim. The purpose of this investigation was to research carbohydrate specificity of a new lectin from fruiting body of Mycena pura and possibilities of its application in histochemical studies. Methods. The lectin has been purified by affinity chromatography on «îvomucine». The lectin carbohydrate specificity has been determined by a reaction of inhibiting haemagglutination by haptens. Histological materials were fixed in 4 % neutral formalin solution. Alkaline phosphatase was revealed in the cryostat unfixed microscopical sections. Results. The lectin yield from fresh fruit bodies of raw material was 9 mg/kg. Mol. mass of the lectin is 40 kDa. The lectin poorly interacted with D-glucose and D-mannose in contrast to lectins from Pisum sativum and Leucojum vernum. The peculiarity of this lectin is its strong interaction with alkaline phosphatase, the highest among twenty tested lectins. However, the receptors for Mycena lectin binding in mammalian tissues are not limited by this enzyme being presented also by glycoconjugates of another structure, as it was shown for fetus calf small intestine and kidney of rat. Conclusions. An important role in the lectin interaction with glycoproteins probably belongs to the disaccharide links of GlcNAcb(1-2Mana(1-6 or GlcNAcb(1- 2Mana(1-2, which not necessarily are terminal

  1. Histochemical approaches to assess cell-to-cell transmission of misfolded proteins in neurodegenerative diseases

    Directory of Open Access Journals (Sweden)

    G. Natale

    2013-03-01

    Full Text Available Formation, aggregation and transmission of abnormal proteins are common features in neurodegenerative disorders including Parkinson’s disease, Alzheimer’s disease, amyotrophic lateral sclerosis, and Huntington’s disease. The mechanisms underlying protein alterations in neurodegenerative diseases remain controversial. Novel findings highlighted altered protein clearing systems as common biochemical pathways which generate protein misfolding, which in turn causes protein aggregation and protein spreading. In fact, proteinaceous aggregates are prone to cell-to-cell propagation. This is reminiscent of what happens in prion disorders, where the prion protein misfolds thus forming aggregates which spread to neighbouring cells. For this reason, the term prionoids is currently used to emphasize how several misfolded proteins are transmitted in neurodegenerative diseases following this prion-like pattern. Histochemical techniques including the use of specific antibodies covering both light and electron microscopy offer a powerful tool to describe these phenomena and investigate specific molecular steps. These include: prion like protein alterations; glycation of prion-like altered proteins to form advanced glycation end-products (AGEs; mechanisms of extracellular secretion; interaction of AGEs with specific receptors placed on neighbouring cells (RAGEs. The present manuscript comments on these phenomena aimed to provide a consistent scenario of the available histochemical approaches to dissect each specific step.

  2. Quantitation and histochemical localization of galectin-1 and galectin-1-reactive glycoconjugates in fetal development of bovine organs.

    Science.gov (United States)

    Kaltner, H; Lips, K S; Reuter, G; Lippert, S; Sinowatz, F; Gabius, H J

    1997-10-01

    The display of cellular oligosaccharide chains is known to undergo marked developmental changes, as monitored histochemically with plant lectins. In conjunction with endogenous lectins respective ligand structures may have a functional role during fetal development. The assumption of a recognitive, functionally productive interplay prompts the study of the expression of a tissue lectin and of lectin-reactive glycoconjugates concomitantly. Focusing on common beta-galactosides as constituents of oligosaccharide chains and the predominant member of the family of galectins in mammals, namely galectin-1, the question therefore is addressed as to whether expression of lectin and lectin-reactive glycoconjugates exhibits alterations, assessed in three morphologically defined fetal stages and in adult bovine organs. Using a sandwich ELISA, the level of the rather ubiquitous galectin-1 is mostly increased in adult organs relative to respective fetal stages, except for the case of kidney. This developmental course is seen rather seldom, when the amounts of lectin-reactive glycoproteins or glycolipids are quantitated in solid-phase assays after tissue homogenization. Western blotting, combined with probing by labeled galectin-1, discloses primarily quantitative changes in the reactivity of individual glycoproteins. Performing the same assays on extract aliquots with a plant agglutinin, namely the galactoside-binding mistletoe lectin, whose fine specificity is different from galectin-1, its reduced extent of binding in solid-phase assays and the disparate profile of lectin-reactive glycoproteins reveal a non-uniform developmental alteration within the group of structural variants of beta-galactosides. Although sample preparation can affect ligand preservation and/or presentation and thus restricts the comparability of biochemical and histochemical results, especially for soluble reactants, the histochemical studies on frozen and paraffin-embedded sections of bovine heart

  3. Immunohistochemical, lectin histochemical and ultrastructural studies of canine transmissible venereal tumor in Brazil

    Directory of Open Access Journals (Sweden)

    Mariana B. Mascarenhas

    Full Text Available ABSTRACT: Canine transmissible venereal tumor (CTVT is a naturally occurring contagious round-cell neoplasia, with poorly understood origin and transmission. This study aims to further investigate the tumor nature through immunohistochemistry, lectin histochemistry and transmission electron microscopy (TEM analysis, and to provide support for diagnostic and differential diagnoses of CTVT. Immunohistochemistry was performed in 10 genital and six exclusively extragenital tumors, which were previously diagnosed by citology and histopathology. CTVT samples were incubated with biotinylated antibodies to specific membrane and cytoplasmic antigens (anti-lysozyme, anti-macrophage, anti-vimentin, anti-CD18, monoclonal anti-CD117, monoclonal anti-CD3, polyclonal anti-CD117, polyclonal CD3 and anti-CD79a, followed by the avidin-biotin-peroxidase complex technique. The lectins Con A, DBA, SBA, PNA, UEA-1, WGA, sWGA, GSL, JSA, PSA, PHA-L, PHA-E and RCA were additionally tested in four genital CTVTs and TEM was performed in eight genital tumors. The anti-vimentin antibody revealed strong immunoreactivity to neoplastic cells in all the assessed samples (16/16. The polyclonal anti-CD3 antibodies showed moderate to strong immunoreactivity in fourteen (14/16 and the polyclonal anti-CD117 in fifteen cases (15/16. There was no immunoreactivity to anti-lysozyme, anti-macrophage, anti-CD18, monoclonal anti-CD117, monoclonal anti-CD3 and anti-CD79a antibodies. At lectin histochemistry, it was observed strong staining of tumor cells to Con-A, PHA-L and RCA. There was no histopathological and immunoreactivity differences between genital and extragenital CTVTs. These findings do not support the hypothesis of histiocytic origin of CTVT. In contrast, the lectin histochemical results were similar to cells from lymphoid/myeloid origin.

  4. The effect of enzymes upon metabolism, storage, and release of carbohydrates in normal and abnormal endometria.

    Science.gov (United States)

    Hughes, E C

    1976-07-01

    This paper presents preliminary data concerning the relationship of various components of glandular epithelium and effect of enzymes on metabolism, storage, and release of certain substances in normal and abnormal endometria. Activity of these endometrial enzymes has been compared between two groups: 252 patients with normal menstrual histories and 156 patients, all over the age of 40, with abnormal uterine bleeding. Material was obtained by endometrial biopsy or curettage. In the pathologic classification of the group of 156, 30 patients had secretory endometria, 88 patients had endometria classified as proliferative, 24 were classified as endometrial hyperplasia, and 14 were classified as adenocarcinoma. All tissue was studied by histologic, histochemical, and biochemical methods. Glycogen synthetase activity caused synthesis of glucose to glycogen, increasing in amount until midcycle, when glycogen phosphorylase activity caused the breakdown to glucose during the regressive stage of endometrial activity. This normal cyclic activity did not occur in the abnormal endometria, where activity of both enzymes continued at low constant tempo. Only the I form of glycogen synthetase increased as the tissue became more hyperplastic. With the constant glycogen content and the increased activity of both the TPN isocitric dehydrogenase and glucose-6-phosphate dehydrogenase in the hyperplastic and cancerous endometria, tissue energy was created, resulting in abnormal cell proliferation. These altered biochemical and cellular activities may be the basis for malignant cell growth.

  5. Histochemical characterisation of oocytes of the swordfish Xiphias gladius

    Directory of Open Access Journals (Sweden)

    Juan B. Ortiz-Delgado

    2008-09-01

    Full Text Available This paper reports a histological, histochemical and immunohistochemical characterisation of growing oocytes of the swordfish Xiphias gladius. The presence and distribution of carbohydrates, proteins, lipids, calcium, iron, vitellogenin/Vg, zona radiata protein/Zrp, metallothionein/Mt, and thyroid hormones/T3-T4 were studied during oogenesis (cortical alveoli, globules, yolk-granules, cytoplasm, follicular and radiata envelopes. During the initial vitellogenic phase, the oocytes showed cortical alveoli and oil globules containing neutral lipids exclusively. During this phase, small yolk granules appeared around the peripheral cytoplasm, and they increased through exogenous vitellogenesis. Yolk granules were composed of glycoproteins, calcium, iron, and proteins rich in lysine, arginine, tyrosine, tryptophan, cysteine and cystine. Vg and Mt were immunohistochemically detected in yolk. The follicular envelope contained proteins rich in amino acids. Moreover, calcium and thyroid hormones (triiodotyronine and thyroxine/T3, T4 were detected in this cell envelope. Cortical alveoli, which contained carboxylated and neutral glycoconjugates, were especially rich in N-acetyl-D-galactosamine, N-acetyl-D-glucosamine, galactose and sialic acid. Finally, the zona radiata was mainly proteinaceous in nature and was composed of calcium and neutral glycoproteins. The egg envelope or chorion and the liver showed specific immunoreactivities by using anti-salmon Zrp as the primary antiserum.

  6. Radioisotope-enzymes and cancer study

    International Nuclear Information System (INIS)

    Luyen, T. van

    2008-01-01

    Cancer is a pathological sign, when the abnormal cells appear in certain human tissues or organs. These cells can reproduce beyond the control of normal biological protection mechanism. Because they reproduce very fast, the metabolic process is accelerated, which causes the extreme need for more energy, substrate and catalyzing enzymes. Based on these needs, we can control the metabolic process by: Stopping supplying the energy. Stopping supplying the substrate and the materials to build up the cell's structure. Stopping operating catalysis by breaking out the enzyme's structure. Destroying the tumor cell by extra agents such as radiations and chemicals. All of these methods have been studied for a long time, which costs too much money, time and labor. Although we succeeded in some ways, the results are still not satisfactory. There are many reasons for this situation but the main one is the lack of information to understand all the processes taking place in the cell and our body. However, as far as we studied, we would like to propose the method to break the structure of the enzyme by nuclear decay process. (author)

  7. [Histochemical and histological investigations on the vagina of the beagle she-dog during various functional conditions (author's transl)].

    Science.gov (United States)

    Wrobel, K H; El Etreby, M F; Günzel, P

    1975-01-01

    Histotopochemistry and histology of vaginal epithelium in female beagles were studied during oestrus, metoestrus-dioestrus, post partum period and at days 20, 30, 40, 50, 60 of pregnancy. During oestrus the epithelium is uniform throughout the whole vagina: it presents itself as a high, uncornified, stratified squamous epithelium with some glycogen and lipid droplets but devoid of leucocytes. The intercellular gaps of the stratum intermedium give strong reactions for ATPase and alkaline phosphatase. The activities of oxidoreductases studied decrease continuously from basal to apical. During gravidity, post partum period and metoestrus-dioestrus distinct morphological and histochemical differences can be stated between the cranial and caudal vaginal portions. Caudal vaginal epithelium outside oestrus remains of stratified squamous type. It exhibits strong mucification during pregnancy. The PAS-positive mucous substances prefer a position in the enlarged intercellular gaps of stratum intermedium and superficiale. During pregnancy the epithelium is relatively rich in acid and completely devoid of alkaline phosphatases. Outside oestrus the epithelium of the cranial vaginal region is a relatively flat, stratified columnar one and contains leucocytes with regularity. Also the cranial vaginal portion undergoes mucification during pregnancy with a maximum about day 33. The mucous material is situated intracellularly and not within the intercellular gaps. Further, larger intraepithelial mucus cysts are observed. Alkaline phosphatase is found during gravidity in the basal region and an adluminal border of the epithelium. The reactions for oxidoreductases are strongest in the columnar cell layer which shows more functional adaptations than the remainder of the epithelium. Histochemical tests for beta-D-glucuronidase and leucine aminopeptidase give negative results in the whole vagina during all different functional stages studied.

  8. Loss of peroxisomes causes oxygen insensitivity of the histochemical assay of glucose-6-phosphate dehydrogenase activity to detect cancer cells

    NARCIS (Netherlands)

    Frederiks, Wilma M.; Vreeling-Sindelárová, Heleen; van Noorden, Cornelis J. F.

    2007-01-01

    Oxygen insensitivity of carcinoma cells and oxygen sensitivity of non-cancer cells in the histochemical assay of glucose-6-phosphate dehydrogenase (G6PD) enables detection of carcinoma cells in unfixed cell smears or cryostat sections of biopsies. The metabolic background of oxygen insensitivity is

  9. Clinicopathological and Molecular Histochemical Review of Skull Base Metastasis from Differentiated Thyroid Carcinoma

    International Nuclear Information System (INIS)

    Matsuno, Akira; Murakami, Mineko; Hoya, Katsumi; Yamada, Shoko M.; Miyamoto, Shinya; Yamada, So; Son, Jae-Hyun; Nishido, Hajime; Ide, Fuyuaki; Nagashima, Hiroshi; Sugaya, Mutsumi; Hirohata, Toshio; Mizutani, Akiko; Okinaga, Hiroko; Ishii, Yudo; Tahara, Shigeyuki; Teramoto, Akira; Osamura, R. Yoshiyuki; Yamazaki, Kazuto; Ishida, Yasuo

    2013-01-01

    Skull base metastasis from differentiated thyroid carcinoma including follicular thyroid carcinoma (FTC) and papillary thyroid carcinoma (PTC) is a rare clinical entity. Eighteen FTC cases and 10 PTC cases showing skull base metastasis have been reported. The most common symptom of skull base metastasis from FTC and PTC is cranial nerve dysfunction. Bone destruction and local invasion to the surrounding soft tissues are common on radiological imaging. Skull base metastases can be the initial clinical presentation of FTC and PTC in the presence of silent primary sites. The possibility of skull base metastasis from FTC and PTC should be considered in patients with the clinical symptoms of cranial nerve dysfunction and radiological findings of bone destruction. A variety of genetic alterations in thyroid tumors have been identified to have a fundamental role in their tumorigenesis. Molecular histochemical studies are useful for elucidating the histopathological features of thyroid carcinoma. Recent molecular findings may provide novel molecular-based treatment strategies for thyroid carcinoma

  10. Studies on the enzymes produced by Basidiomycetes. Part 1. The production of crude enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Hong, J. S.; Kim, D.H.

    1981-01-01

    Cellulase, protease, and xylanase, formation by the basidiomycetes, Pleurotus ostreatus 301 and Lentinus edodes 3-1 in growth on rice straw medium were studied. Cultural conditions adequate for enzyme production and effects of various materials and inorganic salts added to the rice straw media were investigated. Lentinus edodes 3-1 was an excellent producer of cellulase and xylanase, and Pleurotus ostreatus 301 of protease. The optimum conditions for enzyme production were 30 degrees for cellulase production and at 25 degrees for xylanase and protease production, with 75% moisture content and initial pH of 5.0-6.0. The appropriate incubation times for enzyme production were 30 days and 35 days for Pleurotus ostreatus 301 and Lentinus edodes 3-1, respectively. Among the various materials added, defatted soybean, defatted rape seed, or defatted sesame were all effective in enzyme production but reduced mycelial growth. Rice bran was also effective, particularly at a 30% concentration. The addition of inorganic salts enhanced enzyme production. Among inorganic salts, the optimum concentration of CaCO3 was 5%, and that of CaSO4 was 2%.

  11. Death following the ingestion of detergent: an autopsy case with special regard to the histochemical findings.

    Science.gov (United States)

    Kawamoto, Osamu; Ishikawa, Takaki; Oritani, Shigeki; Kuramoto, Yuko; Michiue, Tomomi; Maeda, Hitoshi

    2013-06-01

    We report an autopsy case of death due to accidental ingestion of a liquid laundry detergent with special regard to the histochemical findings. A female inpatient suffering from schizophrenia in a psychiatric institution, was found unconscious lying on the floor of her room, with a container of detergent nearby, and died despite intensive life-support measures. At autopsy, the stomach and duodenum contained whitish translucent foamy viscous fluid, and the mucous membranes, from the esophagus to the duodenum, had diffuse erosions with congestion and edema. There was otherwise no significant pathology other than signs of acute death and hemolysis. Toxicological investigations detected 1-methyl-4-prop-1-en-2-ylcyclohexene (detergent additive) in the gastric contents using headspace-gas chromatography/mass spectrometry, and a nonionic surfactant by a color identification test. Although these substances could not be detected in the blood, body fluid or viscera, histochemical examination using Oil red O demonstrated droplet-like staining in the pulmonary alveoli, suggesting aspiration of detergent, and similar staining in the vasculature of the lung, Kupffer cells of the liver, Bowman capsules of the kidney, and capillaries of the brain, suggesting the systemic effect of ingested/aspirated detergent. These findings were in keeping with death from ingestion of detergent and demonstrated the importance of preventing accidents such as this in healthcare facilities for elderly people.

  12. Morphological characteristics of the digestive tract of Schizodon knerii (Steindachner, 1875, (Characiformes: Anostomidae: An anatomical, histological and histochemical study

    Directory of Open Access Journals (Sweden)

    Marcella L. Dos Santos

    2015-06-01

    Full Text Available The digestive tracts of 44 specimens of Schizodon knerii were studied using anatomical, histological and histochemical techniques. The mouth has terminal position, the lip epithelium is squamous stratified with mucous, claviform cells and taste buds, teeth have an incisive form and the tongue has a stratified squamous epithelium with mucous cells and taste buds. The oropharynx cavity is formed by gill apparatus and pharyngeal teeth. The oesophagus presented pleated mucosa, a stratified squamous epithelium with mucous cells, oesophageal glands and taste buds. The stomach presented cardiac, fundic and pyloric regions, simple prismatic epithelium with tubular glands, with none in the pyloric region. The intestine contains 11-15 pyloric caeca, a simple prismatic epithelium with brush border, goblet cells and lymphocytes. Mucosal cells, oesophageal glands and goblet cells reacted positively to PAS, amylase + PAS, Ab pH 2.5 and Ab pH 0.5. Gastric prismatic cells reacted positively to PAS, amylase + PAS, but only those in the pyloric region reacted positively to Ab pH 2.5 and Ab pH 0.5. The results improve the understanding of the anatomy of S. knerii feeding habits and the presence of mucosubstances in the epithelium, highlights the importance of glycoproteins for passing food through the digestive tract.

  13. The Histological And Histochemical Changes In The Gonads Of The Cotton Leaf Worm SPODOPTERA LITTORALIS (BOISD.)

    International Nuclear Information System (INIS)

    HAZAA, M.A.M.; ALM EL-DIN, M.M.S.; EL-AKHDAR, E.A.H.

    2009-01-01

    The effect of sub-sterilizing dose of gamma radiation (125 Gy) alone or in combination with different concentrations of Tafla leaves extract (Nerium oleander) on the histology and histochemistry of the male and female reproductive systems were studied. The treatment caused histopathological changes in the ovaries including vacuolation, absence of nurse cells, shrinkage of oocyte tissue, clumped of chromatin material and thickness of epithelial cells at some areas. The vacuolation of the testes and absorbation of sperm bundles also represent the damage of germ cells, and disintegration of spermatocytes was most prominent in these organs. Histochemical studies showed clear increment in the protein content of male testes while it showed clear decrement in the female ovaries. The ribonucleic acid (RNA) showed a pronounced increase in both male and female gonads in spite of DNA showed a pronounced decrement.

  14. Qualitative analysis of connective tissue stroma in different grades of oral squamous cell carcinoma: A histochemical study

    Directory of Open Access Journals (Sweden)

    Smitha Kullage

    2017-01-01

    Full Text Available Background: Detection of oral cancer at an early stage is of utmost importance to decrease morbidity and mortality. Tumor stroma plays a critical role during carcinogenesis. There is lack of information regarding the characteristics of the stroma in relation to the invading malignant epithelial cells and the interdependence between stroma and tumor cells in different grades of oral squamous cell carcinoma (OSCC. Aim: The present study was aimed to analyze and compare the nature of stroma in the vicinity of invading tumor islands in different grades of OSCC, using a histochemical technique picrosirius-polarization method. The present study also evaluated and correlated the possible role of inflammatory response in determining the nature of the stroma. Subjects and Methods: The study included thirty cases of different grades of histologically diagnosed OSCC and ten sections of normal buccal mucosa as a control group. Nature of collagen was analyzed using picrosirius-polarization method, and intensity of inflammatory cell infiltrate was recorded using ImageJ software (1.42q, NIH, USA. The results were tabulated and analyzed statistically. Results: Normal oral mucosa showed predominantly reddish birefringence. All cases of well-differentiated OSCC showed reddish-orange color. Nearly 70% moderately differentiated cases showed yellowish-orange (YO and 60% of poorly differentiated cases, showed greenish-yellow (GY. The mean inflammatory cell count was highest in well-differentiated group. There was shift to YO and GY collagen when the cell differentiation and inflammatory cell count decreased in moderate and poorly differentiated cases. Conclusion: Both inflammatory cells and tumor cells have a role in determining the nature of the collagen fibers in tumor stroma of OSCC, probably with opposing effects on stromal behavior and hence both are significant in predicting prognosis.

  15. Histochemical Analysis of Renal Dysplasia with Ureteral Atresia

    International Nuclear Information System (INIS)

    Kawate, Toyoko; Kawamura, Ryuki; Uchida, Takenori; Takahashi, Kyosuke; Hasegawa, Tomohiro; Futamata, Haruo; Katoh, Ryohei; Takeda, Sen

    2009-01-01

    Unilateral small kidney with ureteral obstruction was discovered in a 74-year-old female cadaver during an anatomical dissection course. In order to elucidate the histogenesis of renal dysplasia, we carried out histochemical and immunohistochemical analyses. On macroscopic view, the kidney was approximately 3 cm in length, 2 cm in width and weighed only 9 g. Although the ureter ran from the renal hilus to the bladder, its width was under 2 mm. The renal parenchyma was extremely thin and there was a large congested vein in the renal sinus. On microscopic examination of the kidney, we observed that numerous developing renal tubules had cytokeratin-positive epithelia, most of which were surrounded by concentric fibrosis. However, we could not detect any structures resembling the collecting duct, renal tubules, renal pelvis, or glomeruli. The concentric mesencymal fibrous tissue surrounding the immature renal tubules contained the smooth muscles that were positive for h-caldesmon. Serial sections of the ureter revealed several small and discontinuous lacunae lined by cuboidal and transitional epithelium, which did not constitute a patent lumen through the bladder. This case is a rare case of renal dysplasia with defect in recanalization of the ureteral bud during the early developmental stage

  16. Study of the role of epididymal alpha-glucosidase in the fertility of male rats by the administration of the enzyme inhibitor castanospermine.

    Science.gov (United States)

    Yeung, C H; Cooper, T G

    1994-11-01

    The activity of epididymal alpha-glucosidase in adult rats was rapidly suppressed to histochemically undetectable levels within 2 days by the continuous release of the enzyme inhibitor castanospermine via a peritoneal osmotic pump at a rate of 100-200 nmol h-1. It was established that mating activities overnight depleted 72% of the spermatozoa in the distal cauda, which was replenished in 2 days, and that fertility began to decline 3 weeks after efferent duct ligation. Male rats of proven mating proficiency and fertility were treated with castanospermine, or buffered saline as control, for up to 30 days and enzyme inhibition was confirmed at the end of treatment by histochemistry. Fertility was normal at the first mating test on day 7, significantly decreased at the second mating on day 9, but recovered in a stepwise manner at subsequent matings on days 12 and 14. Delaying the third mating until day 25 did not sustain the transient subfertility. However, prolonging sperm storage in the distal cauda epididymides and preventing replenishment with freshly matured spermatozoa, by efferent duct ligation for 14 days performed on day 15 during castanospermine administration, caused a decrease in fertility and a change in the kinematics of epididymal spermatozoa of the castanospermine-treated group. In control rats, binding of epididymal spermatozoa to Vicia faba, a lectin specific for glucose and glucosamine, and mannose and mannosamine residues, decreased from the proximal caput to the distal corpus coincident with the increase in alpha-glucosidase activity on the epithelial brush border. Lectin binding then increased in the cauda where enzyme activity was absent. However, castanospermine treatment did not significantly alter this binding profile. The findings suggest that epididymal alpha-glucosidase does not play a crucial role in the development of sperm fertilizing capacity, but may be involved in the preparation of spermatozoa for storage.

  17. Histochemical characterization of CNS development in mice: A methodological contribution for evaluation of teratogenic effects

    International Nuclear Information System (INIS)

    Plendl, J.; Schmahl, W.

    1986-01-01

    In the NMRI-mouse strain Dolichos biflorus agglutinin (DBA) showed an outstanding histochemical affinity to some newly developed neuro-glial cells on gestation day 13 and in front of all to the vessel endothelium from gestation day 8 on. The latter affinity pattern, however, was not homogenously distributed within the embryo, but clearly showed varying intensities with advancing cell differentiation. The latter finding was intensely studied at the embryonal central nervous system during the late organogenesis stage (days 10 to 13). Two hours after X-irradiation with 1.0 Gy some irregular DBA-positive patches were found on the surface of neuronal cells which otherwise seemed to be still unaffected. The DBA-affinity of these cells was intensified until 6 hours post irradiation. Simultaneously it was evident that these cells were pre-necrotic. After phagocytotic elimination of these cells the remaining nervous structures were completely DBA-negative. These findings indicate to a possible use of DBA for evaluation of an early lesion pattern in neuroteratological studies. (orig.)

  18. Histochemical and immunohistochemical analyses of the myocardial scar fallowing acute myocardial infarction

    Directory of Open Access Journals (Sweden)

    Tatić Vujadin

    2012-01-01

    Full Text Available Background/Aim. The heart has traditionally been considered as a static organ without capacity of regeneration after trauma. Currently, the more and more often asked question is whether the heart has any intrinsic capacities to regenerate myocytes after myocardial infarction. The aim of this study was to present the existence of the preserved muscle fibers in the myocardial scar following myocardial infarction as well as the presence of numerous cells of various size and form that differently reacted to the used immunohistochemical antibodies. Methods. Histological, histochemical and immunohistochemical analyses of myocardial sections taken from 177 patients who had died of acute myocardial infarction and had the myocardial scar following myocardial infarction, were carried out. More sections taken both from the site of acute infarction and scar were examined by the following methods: hematoxylin-eosin (HE, periodic acid schiff (PAS, PAS-diastasis, Masson trichrom, Malory, van Gieson, vimentin, desmin, myosin, myoglobin, alpha actin, smoth muscle actin (SMA, p53, leukocyte common antigen (LCA, proliferating cell nuclear antigen (PCNA, Ki-67, actin HHF35, CD34, CD31, CD45, CD45Ro, CD8, CD20. Results. In all sections taken from the scar region, larger or smaller islets of the preserved muscle fibers with the signs of hypertrophy were found. In the scar, a large number of cells of various size and form: spindle, oval, elongated with abundant cytoplasm, small with one nucleus and cells with scanty cytoplasm, were found. The present cells differently reacted to histochemical and immunohistochemical methods. Large oval cells showed negative reaction to lymphocytic and leukocytic markers, and positive to alpha actin, actin HHF35, Ki-67, myosin, myoglobin and desmin. Elongated cells were also positive to those markers. Small mononuclear cells showed positive reaction to lymphocytic markers. Endothelial and smooth muscle cells in the blood vessel walls

  19. Study of vitamin D serum level in patients with epilepsy treated with enzyme-inducing and non enzyme-inducing medications

    Directory of Open Access Journals (Sweden)

    sima Hashemipour

    2014-01-01

    Full Text Available Background : Changes of serum minerals and vitamin D have been reported in anticonvulsant drugs user patients. The present study aimed at comparing the changes of serum minerals and vitamin D among two groups of enzyme-inducing and non enzyme-inducing anticonvulsant drug users. Methods: In this study 22 patients treated with enzyme-inducing drugs (carbamazepin, phenytoin, phenobarbital were compared to 25 patients of matched sex, age, and BMI treated with non enzyme-inducing drugs (sodium evaporate, lamotrigine. Serum calcium, phosphate, parathormone, and 25-hydroxy vitamin D were calculated in both groups. Calcium was measured by Calorimetery method. Parathormone and vitamin D were measured using ELISA method. Results: The mean serum vitamin D level was lower in enzyme-inducing than non enzyme-inducing drugs users (15.9±8.3 and 24.2±14.8, P=0.02. Frequency of vitamin D deficiency was higher in enzyme-inducing compared to non enzyme-inducing drugs users, 84% and 48% , respectively (P=0.016. The mean serum calcium level was significantly lower in enzyme-inducing drugs users. (8.7±0.2 vs. 9.0± 0.7, p= 0.05. Four percent in enzyme-inducing group compared to twenty four percent of non enzyme-inducing group had secondary hyperparathyroidism (P=0.016. Conclusion: While vitamin D deficiency is more frequent in enzyme-inducing drug users, secondary hyperparathyroidism is less frequent.

  20. Slow and fast fatigable frog muscle fibres: electrophysiological and histochemical characteristics.

    Science.gov (United States)

    Vydevska-Chichova, M; Mileva, K; Todorova, R; Dimitrova, M; Radicheva, N

    2005-12-01

    Continuous activity of isolated frog gastrocnemius muscle fibres provoked by repetitive stimulation of 5 Hz was used as an experimental model for fatigue development in different fibre types. Parameter changes of the elicited intracellular action potentials and mechanical twitches during the period of uninterrupted activity were used as criteria for fatigue evaluation. Slow fatigable muscle fibre (SMF) and fast fatigable muscle fibre (FMF) types were distinguished depending on the duration of their uninterrupted activity, which was significantly longer in SMFs than in FMFs. The normalized changes of action potential amplitude and duration were significantly smaller in FMFs than in SMFs. The average twitch force and velocity of contraction and relaxation were significantly higher in FMFs than in SMFs. Myosin ATPase (mATPase) and succinate dehydrogenase activity were studied by histochemical assessment in order to validate the fibre type classification based on their electrophysiological characteristics. Based on the relative mATPase reactivity, the fibres of the studied muscle were classified as one of five different types (1-2, 2, 2-3, 3 and tonic). Smaller sized fibres (tonic and type 3) expressed higher succinate dehydrogenase activity than larger sized fibres (type 1-2, 2), which is related to the fatigue resistance. The differences between fatigue development in SMFs and FMFs during continuous activity were associated with fibre-type specific mATPase and succinate dehydrogenase activity.

  1. Histochemical detection of the in vivo produced cellular aldehydes by means of direct Schiff's reaction in CCl/sub 4/ intoxicated rat liver

    Energy Technology Data Exchange (ETDEWEB)

    Taper, H.S.; Somer, M.P.; Lans, M.; Gerlache, J. de; Roberfroid, M.

    1988-04-01

    A histochemical technique for detection of the in vivo induced cellular aldehydes based on the direct Schiff's reaction is reported in this paper. CCl/sub 4/-intoxicated rat liver was used as an experimental model. Fresh and non-pretreated rat liver cryostat sections fixed in 10% formol calcium solution and washed in distilled water were exposed to Schiff's reagent. The sections were then immersed in two baths of sodium bisulphite solution, then in water, dehydrated in ethanol, cleared in xylene and mounted in a synthetic anhydrous mounting medium. As Schiff positive areas presented well circumscribed foci which increased with time following intoxication, semiquantitative planimetric measurements were feasible. The direct Schiff's reaction detects cellular aldehydes in a sensitive, rapid histologically and topographically estimable way. The appearance of these aldehydes precedes distinctly morphological alterations detectable by other histochemical of histological techniques. No positive results were obtained in control, non-intocicated rat livers. Inhibitons of this direct Schiff's was obtained in positive control rat liver sections preincubated in solutions of aldehyde blockers. Histochemical detection of aldehydes may give useful information on different aspects of tissue and organ intoxication such as their topography, appearance, evolution, extension, consequences and effects of treatment. The direct Schiff's reaction can be considered as a valuable tool in fundamental and applied reasearch dealing with various toxicological, environmental, pathological, cancer-related and therapeutic problems.

  2. Molecular determinants of enzyme cold adaptation: comparative structural and computational studies of cold- and warm-adapted enzymes.

    Science.gov (United States)

    Papaleo, Elena; Tiberti, Matteo; Invernizzi, Gaetano; Pasi, Marco; Ranzani, Valeria

    2011-11-01

    The identification of molecular mechanisms underlying enzyme cold adaptation is a hot-topic both for fundamental research and industrial applications. In the present contribution, we review the last decades of structural computational investigations on cold-adapted enzymes in comparison to their warm-adapted counterparts. Comparative sequence and structural studies allow the definition of a multitude of adaptation strategies. Different enzymes carried out diverse mechanisms to adapt to low temperatures, so that a general theory for enzyme cold adaptation cannot be formulated. However, some common features can be traced in dynamic and flexibility properties of these enzymes, as well as in their intra- and inter-molecular interaction networks. Interestingly, the current data suggest that a family-centered point of view is necessary in the comparative analyses of cold- and warm-adapted enzymes. In fact, enzymes belonging to the same family or superfamily, thus sharing at least the three-dimensional fold and common features of the functional sites, have evolved similar structural and dynamic patterns to overcome the detrimental effects of low temperatures.

  3. Promoting effects of phenobarbital on the enzyme-altered foci induced by intrahepatic γ-ray-irradiation in the rat liver

    International Nuclear Information System (INIS)

    Ida, Katsuya; Nakamura, Satoshi; Muro, Hiroyuki; Takai, Michikatsu; Kaneko, Masao

    1995-01-01

    Radiation-induced carcinogenesis of the rat liver using iridium-192 seeds as an intrahepatic radioactive source was studied by enzyme histochemical means. Rats were divided into six groups according to various combinations of one or two iridium-192 or stainless steel seeds and whether they were given a diet containing 0.05% phenobarbital (PB) or a basal diet (BD). Each group were sacrificed at 20, 40, and 60 weeks after intrahepatic insertion of the iridium-192 or stainless steel seeds. γ-Glutamyl transpeptidase (GGT), glucose-6-phosphatase (G6Pase), and adenosine triphosphatase (ATPase) were stained in the liver tissues, and GGT-positive foci were quantified. Liver neoplasm was not evident, but enzyme-altered foci (EAF) were induced by γ-ray irradiation. At every point (20, 40, and 60 weeks) after the insertion of the seeds, the GGT-positive area was larger in the rats given PB than those given BD. Moreover, despite the iridium-192 radioactivity decay, EAF developed continuously in the rats given PB, and persisted in those given BD from 40 to 60 weeks after insertion. These results indicated that phenobarbital promotes the development of EAF initiated by irradiation, as it promotes the process of chemical carcinogenesis in the rat liver. (author)

  4. Cytological and histochemical gradients on two Copaifera langsdorffii Desf. (Fabaceae)--Cecidomyiidae gall systems.

    Science.gov (United States)

    de Oliveira, Denis Coelho; Carneiro, Renê Gonçalves da Silva; Magalhães, Thiago Alves; Isaias, Rosy Mary dos Santos

    2011-10-01

    Previous ultrastructural and histochemical analysis proposed patterns in the accumulation of substances in galls of Diptera: Cecidomyiidae in some plant species of the temperate region. Similar analyses were done to verify the conservativeness of these patterns in the Neotropical region, where a great number of species of Cecidomyiidae is responsible for a wide diversity of morphotypes. Two gall morphotypes induced by Cecidomyiidae in a unique host plant, Copaifera langsdorffii, were studied. The gradients of carbohydrates and the activity of invertases and acid phosphatases were similar, but the cytological gradients and distribution of proteins evidenced that the sites of the induction as well as the amount of neoformed tissues may be peculiar to each gall system. The production of lipids just in the secretory cavities either in the non-galled or galled tissues indicated a potentiality of the host plant which could not be manipulated by the galling insects. Further, the absence of nucleus in the nutritive tissue, an exclusive feature of the horn-shaped galls, indicates cell death attributed to the feeding habit of the galling herbivore.

  5. [Localization of NADPH-diaphorase in the brain of the shore crab Hemigrapsus sanguineus].

    Science.gov (United States)

    Kotsiuba, E P

    2005-01-01

    The presence and localization of NADPH-diaphorase in the cerebral ganglion of the shore crab Hemigrapsus sanguineus was investigated with histochemical and electron histochemical methods. The reactivity of this enzyme was found in the deutrocerebrum, mainly in neuropils of olfactory lobes, the lateral antennular neuropil, a laterodorsal group of cells, and in the oculomotor nerve nucleus. Ultrastructural localization of the enzyme was detected in neurons on the perinuclear membrane, and in membranes of endoplasmic reticulum, in mitochondria and cytosol. The enzyme was found in axons of the antennular nerve, and in terminals of receptor axons in the glomerulus. The obtained data testify to participation of NO in perception and processing of the olfactory information.

  6. Histochemistry and morphoanatomy study on guava fruit during ripening

    Directory of Open Access Journals (Sweden)

    José Renato de Abreu

    2012-03-01

    Full Text Available Guava (Psidium guajava L. is a highly perishable fruit due to its intense metabolism during ripening. Information on the enzyme activities that degrade pectic substances, as well as the amount of pectin, is very contradictory and not clearly defined. Thus, this study aimed to monitor the changes occurred in the fruit during ripening through histochemical, physical, and scanning microscopy processes. Guavas were picked at the half-mature stage and stored for 9 days at 22 ± 1 °C and 78 ± 1% RH. The analyses conducted on the day of harvest (0 and each day of storage (1, 2, 3, 4, 5, 6, 7, and 8 days were: firmness and histochemical analyses (ferric chloride, lugol, comassie blue, vanillin hydrochloric, and ruthenium red observed under an optic microscope and a scanning electron microscope. Ruthenium red showed a high amount of pectin in the cell wall on day zero as well as its decrease in the wall during ripening and its accumulation in the central area of the cell. Scanning microscopy showed loss of the cell structure during ripening. Those observations suggest that the pectin is the main polymer responsible for firmness maintenance in the guava fruit.

  7. Acetylcholinesterase and Nissl staining in the same histological section.

    Science.gov (United States)

    Shipley, M T; Ennis, M; Behbehani, M M

    1989-12-18

    Acetylcholinesterase (AChE) enzyme histochemistry and Nissl staining are commonly utilized in neural architectonic studies. However, the opaque reaction deposit produced by the most commonly used AChE histochemical methods is not compatible with satisfactory Nissl staining. As a result, precise correlation of AChE and Nissl staining necessitates time-consuming comparisons of adjacent sections which may have differential shrinkage. Here, we have modified the Koelle-Friedenwald histochemical reaction for AChE by omitting the final intensification steps. The modified reaction yields a non-opaque reaction product that is selectively visualized by darkfield illumination. This non-intensified darkfield AChE (NIDA) reaction allows clear visualization of Nissl staining in the same histological section. This combined AChE-Nissl method greatly facilitates detailed correlation of enzyme and cytoarchitectonic organization.

  8. Protective Effects of Royal Jelly and Vitamin C against Experimental Hemolytic Anemia on Sex Hormones and Histochemical Testicle Tissue Histochemistry of Adult Mice

    Directory of Open Access Journals (Sweden)

    H Anbara

    2016-03-01

    Full Text Available Introduction: Phenylhydrazine (PHZ is a well-known hemolytic compound inducing intoxication in erythrocytes. Therefore, the present study aimed to evaluate the protective effects of royal jelly and vitamin C against phenylhydrazine-induced damages in mouse testicles. Methods: In this study, 64 adult male mice were randomly and equally assigned to eight groups. The first group received normal saline (0.1ml intraperitoneally. The second group received PHZ (6 mg/100 gr intraperitoneally in 48-hour intervals. The third group received vitamin C (250 mg/kg/day intraperitoneally perday a long with PHZ. The fourth group received royal jelly (100 mg/kg/day through gavage. The fifth group received PHZ along with vitamin C and royal jelly in similar doses to the previous groups. The sixth group received only vitamin C, the seventh group recieved only royal jelly, and finally the eighth group received similar doses of vitamin C and royal jelly. After 35 days, serum and tissue samples were taken and used for histochemical (Mallory-Azan, Alkaline phosphatase, Oil red-O and PAS, and serum analyses (Testosterone, LH, FSH. Results: The study results revealed the histochemical changes in testicular tissue of the phenylhydrazine group, in which vitamin C and royal jelly partly improved the changes. Furthermore, serum analyses demonstrated a significant decrease in testosterone, FSH and LH levels, which this decrease was diminished by royal jelly and vitamin C. Conclusions: Royal jelly and vitamin C seem to have the potential to decrease serum and tissue damages induced by phenylhydrazine via restraining free radicals.

  9. Magnetic enzyme reactors for isolation and study of heterogeneous glycoproteins

    International Nuclear Information System (INIS)

    Korecka, Lucie; Jezova, Jana; Bilkova, Zuzana; Benes, Milan; Horak, Daniel; Hradcova, Olga; Slovakova, Marcela; Viovy, Jean-Louis

    2005-01-01

    The newly developed magnetic micro- and nanoparticles with defined hydrophobicity and porosity were used for the preparation of magnetic enzyme reactors. Magnetic particles with immobilized proteolytic enzymes trypsin, chymotrypsin and papain and with enzyme neuraminidase were used to study the structure of heterogeneous glycoproteins. Factors such as the type of carrier, immobilization procedure, operational and storage stability, and experimental conditions were optimized

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  11. Histochemical detection and comparison of apoptotic cells in the gingival epithelium using hematoxylin and eosin and methyl green-pyronin: A pilot study.

    Science.gov (United States)

    Nayak, Aarati; Raikar, Anita; Kotrashetti, Vijaylaxmi; Nayak, Ramakant; Shree, Sumedha; Kambali, Soumya

    2016-01-01

    Apoptosis plays a critical role in the regulation of inflammation and host immune response. It helps in tissue homeostasis and a disturbance in this is often associated with disease. The use of histochemical stains like hematoxylin and eosin (H and E) and methyl green-pyronin (MGP) can provide a simple and cost-effective method for the detection of apoptotic cells. Study intended to analyze the expression of apoptosis in the gingival epithelium of healthy subjects and in patients with chronic periodontitis, using H and E and MGP. It is also proposed to correlate the apoptotic index (AI) of healthy individuals and those with chronic periodontitis. Twenty gingival biopsies were harvested from which ten samples were of healthy subjects and ten subjects who suffered from chronic periodontitis. Apoptotic cells were analyzed using MGP and H and E under light microscopy. Apoptotic cells were identified at ×100 magnification and AI was calculated. Apoptotic cells were easily distinguishable in MGP stained sections when compared to those stained using H and E. Moreover, apoptotic cell count was higher in chronic periodontitis. Statistical analyses were done by Tukey's multiple post hoc procedure. The study reveals that MGP staining can be used in a routine basic laboratory set up as one of the cost-effective methods for the detection of apoptotic cells.

  12. Histochemical detection and comparison of apoptotic cells in the gingival epithelium using hematoxylin and eosin and methyl green-pyronin: A pilot study

    Directory of Open Access Journals (Sweden)

    Aarati Nayak

    2016-01-01

    Full Text Available Background: Apoptosis plays a critical role in the regulation of inflammation and host immune response. It helps in tissue homeostasis and a disturbance in this is often associated with disease. The use of histochemical stains like hematoxylin and eosin (H and E and methyl green-pyronin (MGP can provide a simple and cost-effective method for the detection of apoptotic cells. Aim: Study intended to analyze the expression of apoptosis in the gingival epithelium of healthy subjects and in patients with chronic periodontitis, using H and E and MGP. It is also proposed to correlate the apoptotic index (AI of healthy individuals and those with chronic periodontitis. Materials and Methods: Twenty gingival biopsies were harvested from which ten samples were of healthy subjects and ten subjects who suffered from chronic periodontitis. Apoptotic cells were analyzed using MGP and H and E under light microscopy. Results: Apoptotic cells were identified at ×100 magnification and AI was calculated. Apoptotic cells were easily distinguishable in MGP stained sections when compared to those stained using H and E. Moreover, apoptotic cell count was higher in chronic periodontitis. Statistical analyses were done by Tukey's multiple post hoc procedure. Conclusion: The study reveals that MGP staining can be used in a routine basic laboratory set up as one of the cost-effective methods for the detection of apoptotic cells.

  13. Histochemical, phytochemical and biological screening of Plinia cauliflora (DC. Kausel, Myrtaceae, leaves

    Directory of Open Access Journals (Sweden)

    Tatiana M. Souza-Moreira

    Full Text Available In this work, chemical and biological activities of crude extracts obtained with 50% ethanol, 70% ethanol, acetone:water (7:3; v/v and chloroform of Plinia cauliflora (DC. Kausel, Myrtaceae, leaves, a native tree from several regions of Brazil, was investigated. Histochemical and phytochemical screenings were done according to characterization reactions and thin layer chromatography. To assist in extracts standardization, total phenol and flavonoids content spectrophotometric was performed. Antioxidant activity was analyzed by percentage of radical scavenging using DPPH solution. Antimicrobial activity was evaluated against Gram-positive, Gram-negative pathogenic bacteria and species of Candida using agar diffusion and minimal inhibitory concentration (MIC determination methods according to standard methods. The leaves presented lipids at secretory cavity and phenols, mainly tannins, in nervures and palisade parenchyma. Polar extracts showed flavonoids, tannins and high content of phenols and flavonoids. The extracts showed great antioxidant activity and antimicrobial activity was better against Candida species than against bacteria.

  14. Biochemical histological and histochemical changes induced in pregnant albino rats as affected by SILYMARIN treatment and/or gamma irradiation

    International Nuclear Information System (INIS)

    Ramadan, F.L.; Othman, A.

    2007-01-01

    Silymarin is a mixture of flavonoids extracted from seeds of milk thistle (Silybum marianum), that has been used in the treatment of liver diseases. Flavonoids are a large group of polycyclic phenols of plant origin that are displaying estrogenic effects. Silybum marianum has been traditionally used in Egypt for its antifertility effect. The objective of this study was to evaluate the side effects of silymarin administration and / or exposure to gamma radiation in pregnant rats. Silymarin at a dose level 75.6 mg/kg body weight was daily administered via an oral stomach tube to pregnant adult albino rats from the 1st to the 20th day of pregnancy while mothers were subjected to gamma radiation (1.5 Gy) as fractionated dose; 0.75 Gy on the 6th day and 0.75 Gy on 12th day of pregnancy. Experimental investigations carried out one day prior to parturition have demonstrated that silymarin intake throughout the whole gestational period induced biochemical, histopathological and histochemical disorders in irradiated mothers. The data obtained revealed that silymarin administration and/or gamma radiation exposure caused significant elevation in levels of follicle stimulating hormone (FSH), the luteinizing hormone (LH) and estradiol in pregnant rats.Moreover, the histopathological results showed different distortions which varied from hyperemic blood vessels, fibroblasts in the ovary, degenerated uterine glands, erosion in the lining epithelia of the uterus and degenerated epithelial cells, necrosis in trophospongium, necrosis in the giant cells, massive blood in the labyrinth and cytoplasmic vacuolation in the placenta. In addition, the histochemical observations revealed various diminutions in each of the polysaccharides, total protein and DNA content. Conclusively, these findings proved that radiation exposure and/or silymarin intake could exert deleterious effect, therefore, it is recommended that radiation occupational workers especially females have to be careful toward

  15. Study of cellulase enzymes self-assembly in aqueous-acetonitrile solvent: Viscosity measurements

    Energy Technology Data Exchange (ETDEWEB)

    Ghaouar, N., E-mail: naoufel-ghaouar@lycos.co [Laboratoire de Physique de la Matiere Molle, Faculte des Sciences de Tunis, Campus Universitaire, 2092 (Tunisia); Institut National des Sciences Appliquees et de Technologie, INSAT, Centre Urbain Nord, BP. 676, Tunis (Tunisia); Aschi, A. [Laboratoire de Physique de la Matiere Molle, Faculte des Sciences de Tunis, Campus Universitaire, 2092 (Tunisia); Belbahri, L. [School of Engineering of Lullier, University of Applied Sciences of Western Switzerland, 150, Route de Presinge, 1254 Jussy (Switzerland); Trabelsi, S.; Gharbi, A. [Laboratoire de Physique de la Matiere Molle, Faculte des Sciences de Tunis, Campus Universitaire, 2092 (Tunisia)

    2009-11-15

    The present study extends the viscosity measurements performed by Ghaouar et al. [Physica B, submitted for publication.] to study the conformational change of the cellulase enzymes in aqueous-acetonitrile mixture. We aim to investigate: (i) the denaturation process by measuring the specific viscosity for temperatures varying between 25 and 65 deg. C and acetonitrile concentrations between 0% and 50%, (ii) the enzyme-enzyme interaction by calculating the Huggins coefficient and (iii) the enzyme sizes by following the hydrodynamic radius for various temperatures. The precipitation of cellulases versus acetonitrile concentration is also considered. We show from all physical quantities measured in this work that the precipitation and the denaturation processes of cellulase enzymes exist together.

  16. Study of cellulase enzymes self-assembly in aqueous-acetonitrile solvent: Viscosity measurements

    International Nuclear Information System (INIS)

    Ghaouar, N.; Aschi, A.; Belbahri, L.; Trabelsi, S.; Gharbi, A.

    2009-01-01

    The present study extends the viscosity measurements performed by Ghaouar et al. [Physica B, submitted for publication.] to study the conformational change of the cellulase enzymes in aqueous-acetonitrile mixture. We aim to investigate: (i) the denaturation process by measuring the specific viscosity for temperatures varying between 25 and 65 deg. C and acetonitrile concentrations between 0% and 50%, (ii) the enzyme-enzyme interaction by calculating the Huggins coefficient and (iii) the enzyme sizes by following the hydrodynamic radius for various temperatures. The precipitation of cellulases versus acetonitrile concentration is also considered. We show from all physical quantities measured in this work that the precipitation and the denaturation processes of cellulase enzymes exist together.

  17. Histochemical differentiation between unirradiated and gamma-irradiated tissue in commercial use of some irradiated vegetables

    International Nuclear Information System (INIS)

    Foa, E.

    1978-01-01

    The use of gamma irradiation as a commercial method for the preservation of fruits and vegetables calls for methods of differentiation between unirradiated and irradiated products. A new approach to studying the influence of gamma irradiation on vegetable tissue at the cellular level by histochemical techniques has been developed by the authors and already applied to a number of fruits and vegetables. The possibility of evidencing radiation effects in the polysaccharide components of the cell wall suggested that these detected differences could be applied to differentiate irradiated from unirradiated tomatoes and potatoes. Some work done to determine changes in the cell wall polysaccharides of gamma-irradiated potatoes and tomatoes and to relate these changes to some other factors, such as storage time and vegetable variety, is reported here. While significant differences have been found in the optical densities of the total polysaccharides of the cell wall as a function of irradiation and of the other variables mentioned, it is not yet possible to use these values as a means of reliable differentiation. (author)

  18. Proteomic analyses for profiling regulated proteins/enzymes by Fucus vesiculosus fucoidan in B16 melanoma cells: A combination of enzyme kinetics functional study.

    Science.gov (United States)

    Wang, Zhi-Jiang; Zheng, Li; Yang, Jun-Mo; Kang, Yani; Park, Yong-Doo

    2018-06-01

    Fucoidans are complex sulfated polysaccharides that have a wide range of biological activities. Previously, we reported the various effects of Fucus vesiculosus fucoidan on tyrosinase and B16 melanoma cells. In this study, to identify fucoidan-targeted proteins in B16 melanoma cells, we performed a proteomics study and integrated enzyme kinetics. We detected 19 candidate proteins dysregulated by fucoidan treatment. Among the probed proteins, the enzyme kinetics of two candidate enzymes, namely lactate dehydrogenase (LDH) as an upregulated protein and superoxide dismutase (SOD) as a downregulated enzyme, were determined. The enzyme kinetics results showed that Fucus vesiculosus fucoidan significantly inhibited LDH catalytic function while it did not affect SOD activity even at a high dose, while only slightly decreased activity (up to 10%) at a low dose. Based on our previous and present observations, fucoidan could inhibit B16 melanoma cells growth via regulating proteins/enzymes expression levels such as LDH and SOD known as cell survival biomarkers. Interestingly, both expression level and enzyme catalytic activity of LDH were regulated by fucoidan, which could directly induce the apoptotic effect on B16 melanoma cells along with SOD downregulation. This study highlights how combining proteomics with enzyme kinetics can yield valuable insights into fucoidan targets. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Histological and histochemical studies on shoot and fruit borer (Leucinodes orbonalis Guenee) resistance in M3 progenies of Solanum macrocarpon L

    International Nuclear Information System (INIS)

    Srinivasappa, K.N.; Ramanjini Gowda, P.H.; Joshi, S.S.; Mahadevu, P.; Thimmaiah, S.K.

    1998-01-01

    Seven M 3 mutant progenies of Solanum macrocarpon L. were subjected to histological and histochemical examination for shoot and fruit borer resistance. The size, thickness and arrangement of cells in cuticle, epicarp, outer and inner mesocarp and number of nuclei were observed under microscope along with staining intensities for insoluble carbohydrates, R.N.A. and protein in both infested and non-infested shoot and fruits. The 5Kr-P 33 -4, 10Kr-P 10 -22 and 10Kr-P 3 -10 mutants which were found to be more resistant have been recorded thicker epicarp and compactly arranged larger mesocarp cells than other mutants. There was an absence of hypertrophy or hyperplacia in all the mutants except 5Kr-P 7 -33 which was slightly susceptible to the borer infestation. A continuous layer deposited with lignin-like substance was observed especially more clear in the above resistant mutants. These mutants also had low protein without proteinoplasts and less intensely stained for insoluble polysaccharides and RNA than other mutants. (author)

  20. Histochemical and structural analysis of mucous glycoprotein secreted by the gill of Mytilus edulis

    International Nuclear Information System (INIS)

    Ahn, Hae-Young.

    1988-01-01

    Studies were carried out to characterized various mucous cells in the gill filament, to ascertain structural characteristics of the secreted mucous glycoproteins, and to determine the ability of the gill epithelium to incorporate [ 14 C]glucosamine as a precursor in the biosynthesis and secretion of mucous glycoproteins. Using histochemical staining techniques, mucous cells containing neutral and acidic mucins were found in the lateral region, whereas mucous cells containing primarily neutral or sulfated mucins were found in the postlateral region. Serotonin, but not dopamine, stimulated the mucous secretion. In tissues pretreated with [ 14 C]glucosamine, the secreted glycoproteins contain incorporated radiolabel. Analysis by column chromatography using Bio-Gel P-2 and P-6 shows that the secretion contains two glycoprotein populations. Glycoprotein II has a molecular weight of 2.3 x 10 4 daltons. Upon alkaline reductive borohydride cleavage of the O-glycosidic linkages of glycoprotein I, about 70% of the radiolabel was removed from the protein. Gas chromatographic analysis of the carbohydrate composition shows that the glycoproteins contains N-acetylglucosamine (GluNAc), N-acetylgalactosamine (GalNAc), and galactose, fucose and mannose. Amino acid analysis shows that the glycoproteins are rich in serine, threonine and proline

  1. Flow-Based Systems for Rapid and High-Precision Enzyme Kinetics Studies

    Directory of Open Access Journals (Sweden)

    Supaporn Kradtap Hartwell

    2012-01-01

    Full Text Available Enzyme kinetics studies normally focus on the initial rate of enzymatic reaction. However, the manual operation of steps of the conventional enzyme kinetics method has some drawbacks. Errors can result from the imprecise time control and time necessary for manual changing the reaction cuvettes into and out of the detector. By using the automatic flow-based analytical systems, enzyme kinetics studies can be carried out at real-time initial rate avoiding the potential errors inherent in manual operation. Flow-based systems have been developed to provide rapid, low-volume, and high-precision analyses that effectively replace the many tedious and high volume requirements of conventional wet chemistry analyses. This article presents various arrangements of flow-based techniques and their potential use in future enzyme kinetics applications.

  2. Polar localization of plasma membrane Ca2+/Mg2+ ATPase correlates with the pattern of steady ionic currents in eggs of Lymnaea stagnalis and Bithynia tentaculata (Mollusca)

    NARCIS (Netherlands)

    D. Zivkovic (Dana); R. Créton (Robbert); G. Zwaan (Gideon); W.C. de Bruijn (Wim); M.R. Dohmen (M.René)

    1990-01-01

    textabstractDuring extrusion of the first polar body in eggs of Lymnaea stagnalis and Bithynia tentaculata a localized Ca2+ /Mg2+ ATPase activity was detected, using Ando's enzyme-cytochemical method for electron microscopy [Ando et al. (1981) Acta Histochem Cytochem 14:705-726]. The enzyme activity

  3. Dipeptidyl peptidase IV is sorted to the secretory granules in pancreatic islet A-cells

    DEFF Research Database (Denmark)

    Poulsen, Mona Dam; Hansen, Gert Helge; Dabelsteen, Erik

    1993-01-01

    Dipeptidyl peptidase IV (DP IV:EC 3.4.14.5) was localized in endocrine cells of pig pancreas by immunohistochemical and enzyme histochemical methods. Immunolight microscopy with both monoclonal and polyclonal antibodies demonstrated DP IV immunoreactivity in cells located in the peripheral part...... of the islets of Langerhans. The antigen is enzymatically active, as shown by enzyme histochemical analysis with a synthetic DP IV substrate. By immunoelectron microscopy (immunogold labeling), the labeling of DP IV in the islets was associated with the secretory granules of the A-cells, as identified by double...... labeling using a monoclonal glucagon antibody as the second primary antibody. These results show that DP IV is sorted to secretory granules in the pig pancreatic islet A-cells. Furthermore, this secretory granule enzyme, as opposed to intestinal brush border DP IV, is suggested to be a soluble protein...

  4. Immobilized enzyme studies in a microscale bioreactor.

    Science.gov (United States)

    Jones, Francis; Forrest, Scott; Palmer, Jim; Lu, Zonghuan; Elmore, John; Elmore, Bill B

    2004-01-01

    Novel microreactors with immobilized enzymes were fabricated using both silicon and polymer-based microfabrication techniques. The effectiveness of these reactors was examined along with their behavior over time. Urease enzyme was successfully incorporated into microchannels of a polymeric matrix of polydimethylsiloxane and through layer-bylayer self-assembly techniques onto silicon. The fabricated microchannels had cross-sectional dimensions ranging from tens to hundreds of micrometers in width and height. The experimental results for continuous-flow microreactors are reported for the conversion of urea to ammonia by urease enzyme. Urea conversions of >90% were observed.

  5. Structural determination and histochemical localization of ghrelin in the red-eared slider turtle, Trachemys scripta elegans.

    Science.gov (United States)

    Kaiya, Hiroyuki; Sakata, Ichiro; Kojima, Masayasu; Hosoda, Hiroshi; Sakai, Takafumi; Kangawa, Kenji

    2004-08-01

    We purified ghrelin peptide and determined the cDNA sequence encoding the precursor protein from the stomach of the red-eared slider turtle, Trachemys scripta elegans. The Trachemys ghrelin is comprised of 25-amino acids and has the sequence GSSFLSPEYQNTQQRKDPKKHTKLN. The third serine residue was modified by n-octanoic (C8:0), decanoic (C10:0) or unsaturated decanoic acid (C10:1). The carboxyl-terminal end of the peptide was not amidated, as seen in the ghrelins of other land vertebrates. Quantitative real-time PCR analysis revealed high levels of gene expression in the stomach and moderate levels in the large intestine and pancreas. Histochemical studies of turtle stomach revealed that ghrelin-immunopositive (ghrelin-ip) cells, which were small and round, were observed in the mucosal layer of the stomach but not in the myenteric plexus, and ghrelin-mRNA-expressing (ghrelin-ex) cells detected by in situ hybridization were scattered in a similar distribution as ghrelin-ip cells. These results indicate that ghrelin is present in reptiles.

  6. Relationship of histochemically detectable altered hepatocyte foci to hepatic tumorigenesis

    Energy Technology Data Exchange (ETDEWEB)

    Peraino, C.; Staffeldt, E.F.; Carnes, B.A.; Ludeman, V.A.; Blomquist, J.A.; Vesselinovitch, S.D.

    1984-01-01

    A new experimental system was used to examine the stages of chemically induced hepatic neoplasia in the rat. The treatment protocol involved the intraperitoneal injection of a single non-necrogenic dose of carcinogen (N-nitrosodiethylamine (NDEA) or benzo(a)pyrene (BP)) into male and female rats within one day after birth, followed by dietary exposure to promoter (0.05% phenobarbital) from weaning. Rats were killed at intervals, and their livers were examined for tumors and for histochemically detectable foci of altered hepatocytes. The data showed that (1) the new treatment protocol was highly efficient in foci and tumor production; (2) growth rates and incidence levels of foci were directly related to hepatocarcinogenic effectiveness (NDEA > BP), whereas both carcinogens had similar effects on foci phenotypic properties; (3) after their formation, foci at a given level of phenotypic complexity did not become progressively more complex; (4) incidence levels of foci were sex-dependent (females > males), but growth rates of foci were the same for both sexes; (5) growth rates and growth capacities (ranges of possible growth rates) of foci were directly related to phenotypic complexity levels of foci; (6) frequencies and phenotypic complexities of foci were inversely related; the reverse was true for tumors, although 10% of the tumors were relatively simple (three markers or fewer); (7) marker frequency distribution patterns were completely different in foci and in tumors.

  7. Stabilization of enzymes in ionic liquids via modification of enzyme charge.

    Science.gov (United States)

    Nordwald, Erik M; Kaar, Joel L

    2013-09-01

    Due to the propensity of ionic liquids (ILs) to inactivate enzymes, the development of strategies to improve enzyme utility in these solvents is critical to fully exploit ILs for biocatalysis. We have developed a strategy to broadly improve enzyme utility in ILs based on elucidating the effect of charge modifications on the function of enzymes in IL environments. Results of stability studies in aqueous-IL mixtures indicated a clear connection between the ratio of enzyme-containing positive-to-negative sites and enzyme stability in ILs. Stability studies of the effect of [BMIM][Cl] and [EMIM][EtSO4 ] on chymotrypsin specifically found an optimum ratio of positively-charged amine-to-negatively-charged acid groups (0.39). At this ratio, the half-life of chymotrypsin was increased 1.6- and 4.3-fold relative to wild-type chymotrypsin in [BMIM][Cl] and [EMIM][EtSO4 ], respectively. The half-lives of lipase and papain were similarly increased as much as 4.0 and 2.4-fold, respectively, in [BMIM][Cl] by modifying the ratio of positive-to-negative sites of each enzyme. More generally, the results of stability studies found that modifications that reduce the ratio of enzyme-containing positive-to-negative sites improve enzyme stability in ILs. Understanding the impact of charge modification on enzyme stability in ILs may ultimately be exploited to rationally engineer enzymes for improved function in IL environments. Copyright © 2013 Wiley Periodicals, Inc.

  8. Protective role of garlic against gamma radiation induced histological and histochemical changes in rat liver

    International Nuclear Information System (INIS)

    Abdel Motaal, N.A.; Abdel Maguid, A.

    2007-01-01

    The present work was planned to evaluate the radioprotective effect of garlic (Allium sativum) against the hazardous action of gamma radiation on liver of rat one and ten days post-exposure. Garlic was orally administered (100 mg/ kg body wt) to rats daily for two weeks before exposure to single dose whole body gamma-irradiation (5Gy). The results showed that exposure of rats to gamma- irradiation caused massive portal infiltration with inflammatory cells, dilatation of blood sinusoids, an increase in the number of Kupffer cells, vacuolation of some hepatocytes as well as pyknosis and karyolysis of hepatic nuclei in the liver tissue. Histochemical examination of liver one day post- irradiation illustrated weak to moderate glycogen particles. While, on ten days post-irradiation, a strong activity for glycogen was detected. The disturbance in carbohydrate metabolism is closely related to the radiation induced histological damage in the liver tissue. Administration of garlic for 2 weeks pre-irradiation reduced the radiation induced histopathological changes and showed marked protection against the tissue damaging effect of radiation. It could be concluded that treatment of rats with garlic before exposure to gamma-irradiation offered a noticeable radioprotective effect of the studied organ

  9. Studies on Ganoderma lucidum III. production of pectolytic enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Chang, L.S.; Tseng, T.C.

    1986-07-01

    Pectolytic enzymes produced by Ganoderma lucidum B in culture and polypropylene bags were investigated. Two pectolytic enzymes, i.e., endo-polygalacturonase (endo-PG) and endo-pectic methyl trans-eliminase (endo-PMTE) were obtained from crude enzymes of G. lucidum B extract from mycelia polypropylene bags. The endo-PMTE has to optimal pH at 4.5 and 8.0. The enzyme stimulated by Ca/sup + +/ ion and preferred only pectin; the enzyme activity decreased at temperature above 50/sup 0/C. The endo-PMTE a and endo-PMTE b, obtained from polypropylene bag with mycelia of G. lucidum B, were purified by 60-80% ammonium sulfate fractionation, Sephadex G-100 gel filtration, DEAE-cellulose ion exchange column chromatography and isoelectric focusing, showing pI at 8.2 and 5.5. Disc gel electrophoresis confirmed two peaks corresponding to endo-PMTE a and b as isoenzymes. Pectolytic enzymes purified by 60-80% ammonium sulfate fraction macerated potato disc and it was more active than the crude enzyme. At pH 4.5, maceration of potato disc by pectolytic enzymes more effective than those at pH 8.0 or 7.0. At pH 8.0, Ca/sup + +/ ion stimulate pectolytic enzyme activities and accelerated maceration.

  10. CD68/macrosialin: not just a histochemical marker.

    Science.gov (United States)

    Chistiakov, Dimitry A; Killingsworth, Murry C; Myasoedova, Veronika A; Orekhov, Alexander N; Bobryshev, Yuri V

    2017-01-01

    CD68 is a heavily glycosylated glycoprotein that is highly expressed in macrophages and other mononuclear phagocytes. Traditionally, CD68 is exploited as a valuable cytochemical marker to immunostain monocyte/macrophages in the histochemical analysis of inflamed tissues, tumor tissues, and other immunohistopathological applications. CD68 alone or in combination with other cell markers of tumor-associated macrophages showed a good predictive value as a prognostic marker of survival in cancer patients. Lowression of CD68 was found in the lymphoid cells, non-hematopoietic cells (fibroblasts, endothelial cells, etc), and tumor cells. Cell-specific CD68 expression and differentiated expression levels are determined by the complex interplay between transcription factors, regulatory transcriptional elements, and epigenetic factors. Human CD68 and its mouse ortholog macrosialin belong to the family of LAMP proteins located in the lysosomal membrane and share many structural similarities such as the presence of the LAMP-like domain. Except for a second LAMP-like domain present in LAMPs, CD68/microsialin has a highly glycosylated mucin-like domain involved in ligand binding. CD68 has been shown to bind oxLDL, phosphatidylserine, apoptotic cells and serve as a receptor for malaria sporozoite in liver infection. CD68 is mainly located in the endosomal/lysosomal compartment but can rapidly shuttle to the cell surface. However, the role of CD68 as a scavenger receptor remains to be confirmed. It seems that CD68 is not involved in binding bacterial/viral pathogens, innate, inflammatory or humoral immune responses, although it may potentially be involved in antigen processing/presentation. CD68 could be functionally important in osteoclasts since its deletion leads to reduced bone resorption capacity. The role of CD68 in atherosclerosis is contradictory.

  11. Measuring the Enzyme Activity of Arabidopsis Deubiquitylating Enzymes.

    Science.gov (United States)

    Kalinowska, Kamila; Nagel, Marie-Kristin; Isono, Erika

    2016-01-01

    Deubiquitylating enzymes, or DUBs, are important regulators of ubiquitin homeostasis and substrate stability, though the molecular mechanisms of most of the DUBs in plants are not yet understood. As different ubiquitin chain types are implicated in different biological pathways, it is important to analyze the enzyme characteristic for studying a DUB. Quantitative analysis of DUB activity is also important to determine enzyme kinetics and the influence of DUB binding proteins on the enzyme activity. Here, we show methods to analyze DUB activity using immunodetection, Coomassie Brilliant Blue staining, and fluorescence measurement that can be useful for understanding the basic characteristic of DUBs.

  12. Study of DNA reconstruction enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Sekiguchi, M [Kyushu Univ., Fukuoka (Japan). Faculty of Science

    1976-12-01

    Description was made of the characteristics and mechanism of 3 reconstructive enzymes which received from M. luteus or E. coli or T4, and of which natures were clarified as reconstructive enzymes of DNA irradiated with ultraviolet rays. As characteristics, the site of breaking, reaction, molecular weight, electric charge in the neutrality and a specific adhesion to DNA irradiated with ultraviolet rays were mentioned. As to mutant of ultraviolet ray sensitivity, hereditary control mechanism of removal and reconstruction by endo-nuclease activation was described, and suggestion was referred to removal and reconstruction of cells of xedoderma pigmentosum which is a hereditary disease of human. Description was also made as to the mechanism of exonuclease activation which separates dimer selectively from irradiated DNA.

  13. Integrative computational approach for genome-based study of microbial lipid-degrading enzymes.

    Science.gov (United States)

    Vorapreeda, Tayvich; Thammarongtham, Chinae; Laoteng, Kobkul

    2016-07-01

    Lipid-degrading or lipolytic enzymes have gained enormous attention in academic and industrial sectors. Several efforts are underway to discover new lipase enzymes from a variety of microorganisms with particular catalytic properties to be used for extensive applications. In addition, various tools and strategies have been implemented to unravel the functional relevance of the versatile lipid-degrading enzymes for special purposes. This review highlights the study of microbial lipid-degrading enzymes through an integrative computational approach. The identification of putative lipase genes from microbial genomes and metagenomic libraries using homology-based mining is discussed, with an emphasis on sequence analysis of conserved motifs and enzyme topology. Molecular modelling of three-dimensional structure on the basis of sequence similarity is shown to be a potential approach for exploring the structural and functional relationships of candidate lipase enzymes. The perspectives on a discriminative framework of cutting-edge tools and technologies, including bioinformatics, computational biology, functional genomics and functional proteomics, intended to facilitate rapid progress in understanding lipolysis mechanism and to discover novel lipid-degrading enzymes of microorganisms are discussed.

  14. Histochemical distribution of zinc in the brain of the rainbow trout, Oncorhynchos myciss. I. The telencephalon

    DEFF Research Database (Denmark)

    Piñuela, C; Baatrup, E; Geneser, F A

    1992-01-01

    was mainly confined to the neuropil, but both moderately and intensely stained nerve cell bodies were of common occurrence. Stained fibers were never observed. The staining revealed a specific distribution pattern which could easily be correlated with the telencephalic nuclei defined on the basis......The present paper which describes the distribution of zinc in the telencephalon of the rainbow trout, Oncorhynchos myciss, is the first report on the distribution of a heavy metal in the fish brain. Zinc was demonstrated histochemically by silver enhancement using the Neo-Timm method. The staining...... of cytoarchitectural features. However, the telencephalon stained much more weakly than the rest of the brain, in striking contrast to the situation in the reptilian, mammalian, and avian brain. In these classes, high staining intensities are observed almost exclusively in the telencephalon. The staining...

  15. Using enzyme folding to explore the mechanism of therapeutic touch: a feasibility study.

    Science.gov (United States)

    Strickland, Mallory L; Boylan, Helen M

    2010-07-01

    The goal of this research is to design a novel model using protein folding to study Therapeutic Touch, a noncontact form of energy manipulation healing. Presented is a feasibility study suggesting that the denaturation path of ribonuclease A may be a useful model to study the energy exchange underlying therapeutic touch. The folding of ribonuclease A serves as a controlled energy-requiring system in which energy manipulation can be measured by the degree of folding achieved. A kinetic assay and fluorescence spectroscopy are used to assess the enzyme-folding state. The data suggest that the kinetic assay is a useful means of assessing the degree of refolding, and specifically, the enzyme function. However, fluorescence spectroscopy was not shown to be an effective measurement of enzyme structure for the purposes of this work. More research is needed to assess the underlying mechanism of therapeutic touch to complement the existing studies. An enzyme-folding model may provide a useful means of studying the energy exchange in therapeutic touch.

  16. Quantitative proteomic study of Aspergillus Fumigatus secretome revealed deamidation of secretory enzymes.

    Science.gov (United States)

    Adav, Sunil S; Ravindran, Anita; Sze, Siu Kwan

    2015-04-24

    Aspergillus sp. plays an essential role in lignocellulosic biomass recycling and is also exploited as cell factories for the production of industrial enzymes. This study profiled the secretome of Aspergillus fumigatus when grown with cellulose, xylan and starch by high throughput quantitative proteomics using isobaric tags for relative and absolute quantification (iTRAQ). Post translational modifications (PTMs) of proteins play a critical role in protein functions. However, our understanding of the PTMs in secretory proteins is limited. Here, we present the identification of PTMs such as deamidation of secreted proteins of A. fumigatus. This study quantified diverse groups of extracellular secreted enzymes and their functional classification revealed cellulases and glycoside hydrolases (32.9%), amylases (0.9%), hemicellulases (16.2%), lignin degrading enzymes (8.1%), peptidases and proteases (11.7%), chitinases, lipases and phosphatases (7.6%), and proteins with unknown function (22.5%). The comparison of quantitative iTRAQ results revealed that cellulose and xylan stimulates expression of specific cellulases and hemicellulases, and their abundance level as a function of substrate. In-depth data analysis revealed deamidation as a major PTM of key cellulose hydrolyzing enzymes like endoglucanases, cellobiohydrolases and glucosidases. Hemicellulose degrading endo-1,4-beta-xylanase, monosidases, xylosidases, lignin degrading laccase, isoamyl alcohol oxidase and oxidoreductases were also found to be deamidated. The filamentous fungi play an essential role in lignocellulosic biomass recycling and fungal strains belonging to Aspergillus were also exploited as cell factories for the production of organic acids, pharmaceuticals, and industrially important enzymes. In this study, extracellular proteins secreted by thermophilic A. fumigatus when grown with cellulose, xylan and starch were profiled using isobaric tags for relative and absolute quantification (iTRAQ) by

  17. Histochemical alternations in the Nissl bodies and ribonucleic acid (RNA) in the spinal, gangalion neurones of gamma irradiated rats

    International Nuclear Information System (INIS)

    Mousa, Tohamy A.; Roushdy, Hamed M.; Raid, Nahed A.; Al-Zahaby, Al-Ahmady S.; Sanad, Samia M.

    1984-01-01

    Four groups of adult male albino rats were subjected to whole body gamma-irradiation at the exposure levels of 200, 400, 600 and 1000 rads and the spinal ganglia were dissected out after different intervals of 3 hr., 1, 3, 5, 7, 10, 15 and 30 days. Nissl bodies and ribonucleic acid were demonstrated histochemically. Gamma irradiation may cause a decrease in RNA synthesis which was reflected in a reduced amount of Nissl substance visible in toluidine blue stained you thick sections of spinal ganglion of gamma irradiated rats and in the total amount of cytoplasmic RNA in pyronin-methyl green stained sections compared with control animals

  18. Characterization of atherosclerosis by histochemical and immunohistochemical methods in African grey parrots (Psittacus erithacus) and Amazon parrots (Amazona spp.).

    Science.gov (United States)

    Fricke, Cornelia; Schmidt, Volker; Cramer, Kerstin; Krautwald-Junghanns, Maria-Elisabeth; Dorrestein, Gerry M

    2009-09-01

    The aim of the study was to characterize atherosclerotic changes in African grey parrots (Psittacus erithacus) and Amazon parrots (Amazona spp.) by histochemical and immunohistochemical methods. Samples of the aorta ascendens and trunci brachiocephalici from 62 African grey parrots and 35 Amazon parrots were stained by hematoxylin and eosin and Elastica van Gieson for grading of atherosclerosis in these birds. Four different stages were differentiated. The incidence of atherosclerosis in the examined parrots was 91.9% in African grey parrots and 91.4% in Amazon parrots. To evaluate the pathogenesis in birds, immunohistochemical methods were performed to demonstrate lymphocytes, macrophages, smooth muscle cells, and chondroitin sulfate. According to the missing lymphocytes and macrophages and the absence of invasion and proliferation of smooth muscle cells in each atherosclerotic stage, "response-to-injury hypothesis" seems inapplicable in parrots. Additionally, we found alterations of vitally important organs (heart, lungs) significantly correlated with atherosclerosis of the aorta ascendens.

  19. An animal model for human masseter muscle: histochemical characterization of mouse, rat, rabbit, cat, dog, pig, and cow masseter muscle

    DEFF Research Database (Denmark)

    Tuxen, A; Kirkeby, S

    1990-01-01

    The masseter muscle of several animal species was investigated by use of a histochemical method for the demonstration of acid-stable and alkali-stable myosin adenosine triphosphatase (ATPase). The following subdivisions of fiber types were used: Type I fibers show weak ATPase activity at pH 9...... II and I fibers, with type II predominating. Cow masseter muscle consisted mainly of type I fibers, although some cow masseter muscles contained a very small number of type II fibers. Pig masseter muscle had both type I, II, and IM fibers. One of the characteristics of human masseter muscle is type...... IM fibers, which are rarely seen in muscles other than the masticatory muscles. Therefore, pig masseter muscle might be a suitable animal model for experimental studies, such as an investigation of the distribution and diameter of fiber types in the masticatory muscles before and after orthognathic...

  20. Morphological, histological and histochemical analysis of the digestive tract of Trachelyopterusstriatulus (Siluriformes: Auchenipteridae

    Directory of Open Access Journals (Sweden)

    Marcella L. dos Santos

    2015-08-01

    Full Text Available ABSTRACT The digestive tract of Trachelyopterus striatulus (Steindachner, 1877 was studied using morphological, histological, and histochemical techniques. The barbels, lips and tongue had stratified squamous epithelium with mucous, claviform cells, and taste buds. Trachelyopterus striatulus had a dental plaque with villiform teeth. The bucopharyngeal cavity was formed by the gill apparatus and pharyngeal teeth with vilifform denticles. The oesophagus presented stratified squamous epithelium with mucous cells and taste buds. The stomach included cardiac, fundic, and pyloric regions and a simple prismatic epithelium with prismatic cells that reacted positively to periodic acid-Schiff (PAS and amylase+PAS. Only the cardiac and pyloric regions responded positively to alcian blue pH 2.5 (Ab pH 2.5 and alcian blue pH 0.5 (Ab pH 0.5. The cardiac and fundic regions exhibited tubular gastric glands. The intestine was 118.90 ± 22.49 mm long with an intestinal coefficient (CO of 0.83 ± 0.13. The epithelium was simple prismatic with a brush border and goblet cells, and a greater number of goblet cells were found in the caudal region of the intestine. The mucous cells and goblet cells reacted positively to PAS, amylase+PAS, Ab pH 2.5, and Ab pH 0.5. We analysed if the function of the mucosubstances and morphological characteristics of the digestive tract of T. striatulus are compatible with omnivorous feeding habit.

  1. Evaluating correlation between serum liver enzymes and toxocariasis: a case control study

    Directory of Open Access Journals (Sweden)

    Hosein Miladi

    2016-06-01

    Full Text Available Objective: To evaluate the prevalence of toxocariasis in individuals with the normal and abnormal level of liver enzymes. Methods: In this case-control study, the serum samples were collected in the individuals referred to diagnostic laboratories of Arak in Iran. A total of 144 sera with abnormal level of liver enzymes were selected as cases and the same numbers of sera with the normal level of liver enzymes also were selected as controls. The sera were examined for anti-Toxocara IgG. Results: Twelve (4.2% sera contained anti-Toxocara antibody and all of them were in the case group. Although the mean of all liver enzymes was significantly different in the two groups (P < 0.05, statistical test showed no relationship between the level of liver enzymes and toxocariasis. Conclusions: It was concluded that the liver enzyme alteration is not the valid indicator for predicting toxocariasis. Because the kind of liver dysfunction, that is caused by the larvae of Toxocara, is unspecified, and it seems factors such as the number of larvae can play a basic role for the emergence of alterations.

  2. Studies on a photoreactivating enzyme from Drosophila melanogaster cultured cells

    International Nuclear Information System (INIS)

    Beck, L.A.

    1982-01-01

    A photoreactivating enzyme was purified from Schneider's Line No. 2 Drosophila melanogaster cultured cells. DEAE cellulose chromatography with high potassium phosphate buffer conditions was used to separate nucleic acids from the protein component of the crude cell extract. The protein pass-through fraction from DEAE cellulose was chromatographed on phosphocellulose followed by hydroxylapatite, using linear potassium phosphate gradients to elute the enzyme. Gel filtration chromatography on Sephacryl S-200 resulted in a 4500-fold purification of the enzyme with a final recovery of 4%. The enzyme has an apparent gel filtration molecular weight of 32,900 (+/- 1350 daltons) and an isoelectric pH of 4.9. Optimum ionic strength for activity is 0.17 at pH 6.5 in potassium phosphate buffer. The action spectrum for photoreactivation in Drosophila has an optimum at 365 nm with a response to wavelengths in the range of 313 to 465 nm. Drosophila photoreactivating enzyme contains an essential RNA that is necessary for activity in vitro. The ability of the enzyme to photoreactivate dimers in vitro is abolished by treatment of the enzyme with ribonucleases, or by disruption of the enzyme-RNA complex by electrophoresis or adsorption to DEAE cellulose. The essential RNA is heterogeneous in size but contains a 10-12 base region that may interact with the active site of the enzyme, and thus is protected from degradation by contaminating RNase activities during purification. The RNA is thought to stabilize the photoreactivating enzyme by maintaining the enzyme in the proper configuration for binding to dimer-containing DNA. It is not known whether this RNA is essential for in vivo photoreactivation

  3. Study on the Correlation between Gene Expression and Enzyme Activity of Seven Key Enzymes and Ginsenoside Content in Ginseng in Over Time in Ji'an, China.

    Science.gov (United States)

    Yin, Juxin; Zhang, Daihui; Zhuang, Jianjian; Huang, Yi; Mu, Ying; Lv, Shaowu

    2017-12-11

    Panax ginseng is a traditional medicine. Fresh ginseng is one of the most important industries related to ginseng development, and fresh ginseng of varying ages has different medicinal properties. Previous research has not systematically reported the correlation between changes in key enzyme activity with changes in ginsenoside content in fresh ginseng over time. In this study, for the first time, we use ginseng samples of varying ages in Ji'an and systematically reported the changes in the activity of seven key enzymes (HMGR, FPS, SS, SE, DS, CYP450, and GT). We investigated the content of ginsenoside and gene expression of these key enzymes. Ginsenoside content was measured using HPLC. HPLC, GC-MS, and LC-MS were combined to measure the enzyme activity of the key enzymes. Quantitative PCR was used in the investigation of gene expression. By analyzing the correlation between the enzyme activity and the transcription level of the key enzymes with ginsenoside content, we found that DS and GT enzyme activities are significantly correlated with the ginsenoside content in different ages of ginseng. Our findings might provide a new strategy to discriminate between ginseng of different years. Meanwhile, this research provides important information for the in-depth study of ginsenoside biosynthesis.

  4. Enzyme study of the separate stages in alcohol fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Mar Monux, D

    1968-01-01

    The precise roles of ATP, DNA, and NADP in interaction with enzymes in certain of the 11 phases of fermentation are outlined. Individual enzymes which take part in the 11 phases are: (1) hexose transferase; (2) phosphohexoseisomerase; (3) fructosinase; (4) aldolase; (5) an SH-enzyme; (6) 3-phosphoglycero-1-phosphotransferase; (7) ghosphoglyceromutosase; (8) 2-phosphoglycerohydrolase; (9) pyruvic transferase; (10) pyruvic decarboxylase; (11) alcohol dehydrogenase.

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

    African Journals Online (AJOL)

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

  6. Micromorphology and histochemical traits of staminal osmophores in Asphodelus aestivus Brot. flower

    Directory of Open Access Journals (Sweden)

    Elżbieta Weryszko-Chmielewska

    2012-12-01

    Full Text Available The conducted studies pertained to micromorphology of the surface of epidermis cells and histological traits of staminal filaments of Asphodelus aestivus Brot. flowers. The structure of the filaments was analyzed in a light microscope (LM using various histochemical techniques. The morphology of the surface of the epidermis of filaments was observed in scanning electron microscope (SEM. Filaments Asphodelus aestivus accrete together with the basal part of the abaxial surface with the leaves of perianth. Their lower, wider, and flattened part surrounds the ovary. The epidermis of the staminal osmophores creates papilliose cells and unicellular hairs of various sizes. In the uppermost part of these structures, round marks in the cuticle layer after the emission of discharge were observed with the SEM. The outside, convex wall of the isodiametric cells of the epidermis, papillae and hairs was significantly thicker from the remaining walls. It was covered with cuticle of different ornamentation. The cells that created papillae and hairs had a large, centrally located vacuole and a thin layer of cytoplasm with numerous small vacuoles as well as large, often lobed nuclei. In the protoplasts of these cells the presence of plastids and lipid droplets was noted. During the time of secretion of elicitor between the wall and cuticle of the epidermis cells, convex bubbles were formed, in which the secreted substance was accumulated. At the end of secretion, on the surface of papillae, hairs and other cells of the epidermis, irregularly protruding cuticle was observed. It was noted that the composition of staminal osmophores in the flowers of Asphodelus aestivus includes papillae, hairs and cells of the epidermis that do not form papillae.

  7. Insights on Cytochrome P450 Enzymes and Inhibitors Obtained Through QSAR Studies

    Directory of Open Access Journals (Sweden)

    Maryam Foroozesh

    2012-08-01

    Full Text Available The cytochrome P450 (CYP superfamily of heme enzymes play an important role in the metabolism of a large number of endogenous and exogenous compounds, including most of the drugs currently on the market. Inhibitors of CYP enzymes have important roles in the treatment of several disease conditions such as numerous cancers and fungal infections in addition to their critical role in drug-drug interactions. Structure activity relationships (SAR, and three-dimensional quantitative structure activity relationships (3D-QSAR represent important tools in understanding the interactions of the inhibitors with the active sites of the CYP enzymes. A comprehensive account of the QSAR studies on the major human CYPs 1A1, 1A2, 1B1, 2A6, 2B6, 2C9, 2C19, 2D6, 2E1, 3A4 and a few other CYPs are detailed in this review which will provide us with an insight into the individual/common characteristics of the active sites of these enzymes and the enzyme-inhibitor interactions.

  8. Study on the inactivation of intracellular enzyme molecules by X-ray irradiation

    International Nuclear Information System (INIS)

    Lee, S.B.

    1977-01-01

    Inactivation of the glutamic acid dehydrogenase and glucose-6-phosphate dehydrogenase enzyme molecules in the Ehrlich ascites tumor cells of the mouse were studied. The above mentioned intracellular enzyme molecules were irradiated by the X-ray radiation under the condition of 65 kV, 1 Amp under the atmosphere of nitrogen gases and by 4 0 C. Thereby, irradiation doses were 580 KR/min(error: +-3%). After irradiation, the cell homogentes were prepared through liquid air techniques. There after, the activities of the enzymes were measured with photometric method given by O. Warburg and W. Christian. The dose effect curves of the activities of the two enzymes by the X-ray irradiation showed both exponential and the inactivation doses were 6.5x10 6 and 5.0x10 6 R respectively. These results showed one side that the inactivation process of the intracellular enzyme molecules was one hit reaction after target theory, and the other side that this inactivation process could not be the primary causes of the death through X-ray irradiation of the vertebrate animals, because of the high resistance of the intracellular protein molecules against X-ray irradiation. The one hit reaction by the inactivation process of the irradiated intracellular enzyme molecules was discussed. (author)

  9. New Insights about Enzyme Evolution from Large Scale Studies of Sequence and Structure Relationships*

    Science.gov (United States)

    Brown, Shoshana D.; Babbitt, Patricia C.

    2014-01-01

    Understanding how enzymes have evolved offers clues about their structure-function relationships and mechanisms. Here, we describe evolution of functionally diverse enzyme superfamilies, each representing a large set of sequences that evolved from a common ancestor and that retain conserved features of their structures and active sites. Using several examples, we describe the different structural strategies nature has used to evolve new reaction and substrate specificities in each unique superfamily. The results provide insight about enzyme evolution that is not easily obtained from studies of one or only a few enzymes. PMID:25210038

  10. Study of antioxidant enzymes superoxide dismutase and glutathione peroxidase levels in tobacco chewers and smokers: A pilot study

    Directory of Open Access Journals (Sweden)

    Chundru Venkata Naga Sirisha

    2013-01-01

    Conclusions: The present study gave us an insight about the relationship between antioxidant enzyme activity, oxidative stress and tobacco. The altered antioxidant enzyme levels observed in this study will act as a predictor for pre potentially malignant lesions. Therefore an early intervention of tobacco habit and its related oxidative stress would prevent the development of tobacco induced lesions.

  11. Histochemical changes of capillaries in rat brain cortex after irradiation with supralethal doses of gamma radiation

    International Nuclear Information System (INIS)

    Kamarad, V.; Dosoudilova, M.

    1987-01-01

    Changes were studied in the activities of alkaline phosphatase, ATP-splitting enzyme, thiaminepyrophosphatase, acetylcholinesterase, and of butyrylcholinesterase in the capillary sheet of the rat brain cortex of the laterobasal section of a parietal lobe following irradiation with 150 and 300 Gy. The animals were exposed to local irradiation of the head with gamma radiation using 60 Co at a dose rate of 6.9 Gy per min. The material was removed at the intervals of 30 and 60 mins after irradiation. All the studied enzymes, except the ATP-splitting enzyme, showed identical reaction to irradiation. At both intervals, the reaction after irradiation with 300 Gy was lower when compared to that after irradiation with 150 Gy. 30 mins after irradiation with 150 Gy an increased enzyme activity was shown followed by a marked decrease in the activity 60 mins after irradiation, compared with findings obtained from control animals. No similar time dependence was observed after irradiation with 300 Gy. The ATP-splitting enzyme showed a significant decrease in the activity 30 mins after irradiation with 150 Gy. On the other hand, 60 mins after irradiation with 150 Gy and at both time intervals after irradiation with 300 Gy, the activity was higher than that in control animals. (author). 6 figs., 14 refs

  12. Study of thermal and chemical effects on cellulase enzymes: Viscosity measurements

    International Nuclear Information System (INIS)

    Ghaouar, N.; Aschi, A.; Belbahri, L.; Trabelsi, S.; Gharbi, A.

    2009-01-01

    The behaviour of cellulase enzymes in phosphate saline buffer has been studied over a wide range of temperatures and enzyme concentrations by using viscosity measurements. To characterize the conformation change of cellulase versus temperature and chemical denaturants, such as guanidinium chloride (GdmCl) and urea, the information about the intrinsic viscosity and the hydrodynamic radius are necessary. The dependence of the intrinsic viscosity and the hydrodynamic radius in its random coil conformation on temperature and denaturant concentration were studied. Our results and discussions are limited to the dilute regime of concentration because of abnormalities in conformation observed in the very dilute regime due to the presence of capillary absorption effects.

  13. Study of thermal and chemical effects on cellulase enzymes: Viscosity measurements

    Energy Technology Data Exchange (ETDEWEB)

    Ghaouar, N., E-mail: naoufel-ghaouar@lycos.co [Laboratoire de Physique de la Matiere Molle, Faculte des Sciences de Tunis, Campus Universitaire, 2092 (Tunisia); Institut National des Sciences Appliquees et de Technologie, INSAT, Centre Urbain Nord, BP. 676, Tunis (Tunisia); Aschi, A. [Laboratoire de Physique de la Matiere Molle, Faculte des Sciences de Tunis, Campus Universitaire, 2092 (Tunisia); Belbahri, L. [Agronomy Department, School of Engineering of Lullier, University of Applied Sciences of Western Switzerland, 150, Route de Presinge, 1254 Jussy (Switzerland); Trabelsi, S.; Gharbi, A. [Laboratoire de Physique de la Matiere Molle, Faculte des Sciences de Tunis, Campus Universitaire, 2092 (Tunisia)

    2009-11-15

    The behaviour of cellulase enzymes in phosphate saline buffer has been studied over a wide range of temperatures and enzyme concentrations by using viscosity measurements. To characterize the conformation change of cellulase versus temperature and chemical denaturants, such as guanidinium chloride (GdmCl) and urea, the information about the intrinsic viscosity and the hydrodynamic radius are necessary. The dependence of the intrinsic viscosity and the hydrodynamic radius in its random coil conformation on temperature and denaturant concentration were studied. Our results and discussions are limited to the dilute regime of concentration because of abnormalities in conformation observed in the very dilute regime due to the presence of capillary absorption effects.

  14. New insights about enzyme evolution from large scale studies of sequence and structure relationships.

    Science.gov (United States)

    Brown, Shoshana D; Babbitt, Patricia C

    2014-10-31

    Understanding how enzymes have evolved offers clues about their structure-function relationships and mechanisms. Here, we describe evolution of functionally diverse enzyme superfamilies, each representing a large set of sequences that evolved from a common ancestor and that retain conserved features of their structures and active sites. Using several examples, we describe the different structural strategies nature has used to evolve new reaction and substrate specificities in each unique superfamily. The results provide insight about enzyme evolution that is not easily obtained from studies of one or only a few enzymes. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  15. Locus ceruleus neurons in people with autism contain no histochemically-detectable mercury.

    Science.gov (United States)

    Pamphlett, Roger; Kum Jew, Stephen

    2016-02-01

    Exposure to environmental mercury has been proposed to play a part in autism. Mercury is selectively taken up by the human locus ceruleus, a region of the brain that has been implicated in autism. We therefore looked for the presence of mercury in the locus ceruleus of people who had autism, using the histochemical technique of autometallography which can detect nanogram amounts of mercury in tissues. In addition, we sought evidence of damage to locus ceruleus neurons in autism by immunostaining for hyperphosphorylated tau. No mercury was found in any neurons of the locus ceruleus of 6 individuals with autism (5 male, 1 female, age range 16-48 years). Mercury was present in locus ceruleus neurons in 7 of 11 (64%) age-matched control individuals who did not have autism, which is significantly more than in individuals with autism. No increase in numbers of locus ceruleus neurons containing hyperphosphorylated tau was detected in people with autism. In conclusion, most people with autism have not been exposed early in life to quantities of mercury large enough to be found later in adult locus ceruleus neurons. Human locus ceruleus neurons are sensitive indicators of mercury exposure, and mercury appears to remain in these neurons indefinitely, so these findings do not support the hypothesis that mercury neurotoxicity plays a role in autism.

  16. Metagenomics as a Tool for Enzyme Discovery: Hydrolytic Enzymes from Marine-Related Metagenomes.

    Science.gov (United States)

    Popovic, Ana; Tchigvintsev, Anatoly; Tran, Hai; Chernikova, Tatyana N; Golyshina, Olga V; Yakimov, Michail M; Golyshin, Peter N; Yakunin, Alexander F

    2015-01-01

    This chapter discusses metagenomics and its application for enzyme discovery, with a focus on hydrolytic enzymes from marine metagenomic libraries. With less than one percent of culturable microorganisms in the environment, metagenomics, or the collective study of community genetics, has opened up a rich pool of uncharacterized metabolic pathways, enzymes, and adaptations. This great untapped pool of genes provides the particularly exciting potential to mine for new biochemical activities or novel enzymes with activities tailored to peculiar sets of environmental conditions. Metagenomes also represent a huge reservoir of novel enzymes for applications in biocatalysis, biofuels, and bioremediation. Here we present the results of enzyme discovery for four enzyme activities, of particular industrial or environmental interest, including esterase/lipase, glycosyl hydrolase, protease and dehalogenase.

  17. Histochemical demonstration of mercury in the olfactory system of salmon (Salmo salar L.) following treatments with dietary methylmercuric chloride and dissolved mercuric chloride

    DEFF Research Database (Denmark)

    Baatrup, E; Døving, K B

    1991-01-01

    The deposition of organic and inorganic mercury compounds was studied histochemically in the salmon (Salmo salar L.) olfactory system. One group of salmon was given fodder pellets containing methylmercuric chloride (CH3HgCl, 99 micrograms Hg/g) for 4 weeks. Other groups of fish were exposed...... to dissolved mercuric chloride (HgCl2, 270 micrograms Hg/liter) for 2, 6, and 12 hr, respectively. In both series of experiments, the radioisotope 203Hg was included in order to determine the accumulation of mercury in the olfactory system. Gamma-spectrometry showed that both mercury compounds accumulated...... in the olfactory rosettes and their nerves. Tissue sections from the rosettes and olfactory nerves were subjected to autometallographic silver enhancement, thereby rendering mercury deposits visible for light and electron microscopy. Microscopic analysis demonstrated an intense and comprehensive Hg deposition...

  18. Studies on the preparation of immobilized enzymes by radio-polymerization, 10

    International Nuclear Information System (INIS)

    Amarakone, S.P.; Hayashi, Toru; Kawashima, Koji.

    1983-01-01

    β-Galactosidase of E. coli origin was immobilized in the form of beads by the radiopolymerization of different combinations of monomers using a gamma irradiation technique. With the dialysed enzyme, recoveries of over 300 % could be obtained on suitable monomer combinations containing magnesium and sodium acrylates. The recovery of the enzyme also depended on the irradiation time. The immobilized enzyme had better pH and temperature stability and was less affected by the presence of metal ions in the medium, compared to the native enzyme. The optimum pH and temperatures of the immobilized enzyme were different from those of the native enzyme and were 7.0 to 7.5 and 50 deg C respectively. The immobilized enzyme was used in a column for the continuous determination of lactose with a standard type autoanalyser. Good linearity could be observed even up to 3 % lactose in the sample. (author)

  19. Immuno-histochemical features of the structure of foetuses' uterus from the mothers with pregnancy complications

    Directory of Open Access Journals (Sweden)

    Larisa Kupriianova

    2017-02-01

    Full Text Available Material of the research includes uterus of foetuses, that were dead on the gestational term between 21 and 41 weeks. According to peculiarities in the pregnancy course this material was divided into groups: foetuses from mothers with physiological pregnancy; foetuses from mothers. whose pregnancy takes its course on the background of the PE with different stages of the severity; and, finally, foetuses from mothers, whose pregnancy was complicated by the chronic infection of lower genital tracts. Research methods: macroscopic, histological, histochemical, immunohistochemical, morphometric, statistical. It was shown an excessive proliferation of the connective tissue in all structural components, in the composition of which prevails an immature collagen of the III type. It was also increased a production of the endothelin-1 by the vascular component of organs. In addition, it was defined an oppression of the functional activity of epithelial component by mucosa, which was expressed like decreasing of the hormonal activity of the the organ and increasing of the manifestation stage of apoptosis changes.

  20. High levels of xanthine oxidoreductase in rat endothelial, epithelial and connective tissue cells. A relation between localization and function?

    NARCIS (Netherlands)

    Kooij, A.; Bosch, K. S.; Frederiks, W. M.; van Noorden, C. J.

    1992-01-01

    The localization of xanthine oxidoreductase activity was investigated in unfixed cryostat sections of various rat tissues by an enzyme histochemical method which specifically demonstrates both the dehydrogenase and oxidase forms of xanthine oxidoreductase. High activity was found in epithelial cells

  1. Molecular dynamics simulation studies of radiation damaged DNA. Molecules and repair enzymes

    International Nuclear Information System (INIS)

    Pinak, Miroslav

    2004-12-01

    Molecular dynamics (MD) studies on several radiation damages to DNA and their recognition by repair enzymes are introduced in order to describe the stepwise description of molecular process observed at radiation lesion sites. MD studies were performed on pyrimidine (thymine dimer, thymine glycol) and purine (8-oxoguanine) lesions using an MD simulation code AMBER 5.0. The force field was modified for each lesion. In all cases the significant structural changes in the DNA double helical structure were observed; a) the breaking of hydrogen bond network between complementary bases and resulting opening of the double helix (8-oxoguanine); b) the sharp bending of the DNA helix centered at the lesion site (thymine dimer, thymine glycol); and c) the flipping-out base on the strand complementary to the lesion (8-oxoguanine). These changes were related to the overall collapsing double helical structure around the lesion and might facilitate the docking of the repair enzyme into the DNA and formation of DNA-enzyme complex. In addition to the structural changes, at lesion sites there were found electrostatic interaction energy values different from those at native sites (thymine dimer -10 kcal/mol, thymine glycol -26 kcal/mol, 8-oxoguanine -48 kcal/mol). These values of electrostatic energy may discriminate lesion from values at native sites (thymine 0 kcal/mol, guanine -37 kcal/mol) and enable a repair enzyme to recognize a lesion during scanning DNA surface. The observed specific structural conformation and energetic properties at the lesions sites are factors that guide a repair enzyme to discriminate lesions from non-damaged native DNA segments. (author)

  2. Classification of 27 Tumor-Associated Antigens by Histochemical Analysis of 36 Freshly Resected Lung Cancer Tissues

    Directory of Open Access Journals (Sweden)

    Gene Kurosawa

    2016-11-01

    Full Text Available In previous studies, we identified 29 tumor-associated antigens (TAAs and isolated 488 human monoclonal antibodies (mAbs that specifically bind to one of the 29 TAAs. In the present study, we performed histochemical analysis of 36 freshly resected lung cancer tissues by using 60 mAbs against 27 TAAs. Comparison of the staining patterns of tumor cells, bronchial epithelial cells, and normal pulmonary alveolus cells and interalveolar septum allowed us to determine the type and location of cells that express target molecules, as well as the degree of expression. The patterns were classified into 7 categories. While multiple Abs were used against certain TAAs, the differences observed among them should be derived from differences in the binding activity and/or the epitope. Thus, such data indicate the versatility of respective clones as anti-cancer drugs. Although the information obtained was limited to the lung and bronchial tube, bronchial epithelial cells represent normal growing cells, and therefore, the data are informative. The results indicate that 9 of the 27 TAAs are suitable targets for therapeutic Abs. These 9 Ags include EGFR, HER2, TfR, and integrin α6β4. Based on our findings, a pharmaceutical company has started to develop anti-cancer drugs by using Abs to TfR and integrin α6β4. HGFR, PTP-LAR, CD147, CDCP1, and integrin αvβ3 are also appropriate targets for therapeutic purposes.

  3. Studies of the immobilization of enzymes and microorganism pt.1

    International Nuclear Information System (INIS)

    Kim, S.K.

    1979-01-01

    A new method of immobilization of glucose oxidase by the aerobic gamma radiation of synthetic monomers was developed. The radiocopolymerization was conducted aerobically at -70 to-80 degC with the mixture of several polyfunctional esters, acrylates and native enzyme. The retained activity of immobilized glucoseoxidase was about 50 to 55% when a NK 23G ester, acrylamide-bis and water mixture (1:1:2) in cold toluene treated with 450 Krad of gamma radiation. The radiation dose did not influence significantly to the enzyme activity. The solvents used to prepare the beads of glucose oxidase and monomers were toluene, n-hexane, petoleum ether and chloroform. 0.05M tris-gycerol(pH 7.0) was a more suitable buffer solution for immobilizing the enzyme than was 0.02M phosphate. Immobilization of glucose oxidase shifted the optimum pH for its reaction from 6.0 to 6.5. The pH profile for the immobilized enzyme showed a broad range of optimum activity while the native enzyme gave a sharp pick for its optimum pH value. The immobilized enzyme reaction temperature was at the range of 30-40 degreesC. (Author)

  4. [Interaction between CYP450 enzymes and metabolism of traditional Chinese medicine as well as enzyme activity assay].

    Science.gov (United States)

    Lu, Tu-lin; Su, Lian-lin; Ji, De; Gu, Wei; Mao, Chun-qin

    2015-09-01

    Drugs are exogenous compounds for human bodies, and will be metabolized by many enzymes after administration. CYP450 enzyme, as a major metabolic enzyme, is an important phase I drug metabolizing enzyme. In human bodies, about 75% of drug metabolism is conducted by CYP450 enzymes, and CYP450 enzymes is the key factor for drug interactions between traditional Chinese medicine( TCM) -TCM, TCM-medicine and other drug combination. In order to make clear the interaction between metabolic enzymes and TCM metabolism, we generally chose the enzymatic activity as an evaluation index. That is to say, the enhancement or reduction of CYP450 enzyme activity was used to infer the inducing or inhibitory effect of active ingredients and extracts of traditional Chinese medicine on enzymes. At present, the common method for measuring metabolic enzyme activity is Cocktail probe drugs, and it is the key to select the suitable probe substrates. This is of great significance for study drug's absorption, distribution, metabolism and excretion (ADME) process in organisms. The study focuses on the interaction between TCMs, active ingredients, herbal extracts, cocktail probe substrates as well as CYP450 enzymes, in order to guide future studies.

  5. Enzyme

    Science.gov (United States)

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

  6. Enzyme structure and interaction with inhibitors

    International Nuclear Information System (INIS)

    London, R.E.

    1983-01-01

    This article reviews some of the results of studies on the 13 C-labeled enzyme dihydrofolate reductase (DHFR). Nuclear magnetic resonance (NMR) techniques are used in combination with isotopic labeling to learn about the structure and dynamics of this enzyme. 13 C-labeling is used for the purpose of studying enzyme/substrate and enzyme/inhibitor interactions. A second set of studies with DHFR was designed to investigate the basis for the high affinity between the inhibitor methotrexate and DHFR. The label was placed on the inhibitor, rather than the enzyme

  7. Stochastic theory of interfacial enzyme kinetics: A kinetic Monte Carlo study

    International Nuclear Information System (INIS)

    Das, Biswajit; Gangopadhyay, Gautam

    2012-01-01

    Graphical abstract: Stochastic theory of interfacial enzyme kinetics is formulated. Numerical results of macroscopic phenomenon of lag-burst kinetics is obtained by using a kinetic Monte Carlo approach to single enzyme activity. Highlights: ► An enzyme is attached with the fluid state phospholipid molecules on the Langmuir monolayer. ► Through the diffusion, the enzyme molecule reaches the gel–fluid interface. ► After hydrolysing a phospholipid molecule it predominantly leaves the surface in the lag phase. ► The enzyme is strictly attached to the surface with scooting mode of motion and the burst phase appears. - Abstract: In the spirit of Gillespie’s stochastic approach we have formulated a theory to explore the advancement of the interfacial enzyme kinetics at the single enzyme level which is ultimately utilized to obtain the ensemble average macroscopic feature, lag-burst kinetics. We have provided a theory of the transition from the lag phase to the burst phase kinetics by considering the gradual development of electrostatic interaction among the positively charged enzyme and negatively charged product molecules deposited on the phospholipid surface. It is shown that the different diffusion time scales of the enzyme over the fluid and product regions are responsible for the memory effect in the correlation of successive turnover events of the hopping mode in the single trajectory analysis which again is reflected on the non-Gaussian distribution of turnover times on the macroscopic kinetics in the lag phase unlike the burst phase kinetics.

  8. Enzyme Immobilization: An Overview on Methods, Support Material, and Applications of Immobilized Enzymes.

    Science.gov (United States)

    Sirisha, V L; Jain, Ankita; Jain, Amita

    Immobilized enzymes can be used in a wide range of processes. In recent years, a variety of new approaches have emerged for the immobilization of enzymes that have greater efficiency and wider usage. During the course of the last two decades, this area has rapidly expanded into a multidisciplinary field. This current study is a comprehensive review of a variety of literature produced on the different enzymes that have been immobilized on various supporting materials. These immobilized enzymes have a wide range of applications. These include applications in the sugar, fish, and wine industries, where they are used for removing organic compounds from waste water. This study also reviews their use in sophisticated biosensors for metabolite control and in situ measurements of environmental pollutants. Immobilized enzymes also find significant application in drug metabolism, biodiesel and antibiotic production, bioremediation, and the food industry. The widespread usage of immobilized enzymes is largely due to the fact that they are cheaper, environment friendly, and much easier to use when compared to equivalent technologies. © 2016 Elsevier Inc. All rights reserved.

  9. Combined histochemical staining, RNA amplification, regional, and single cell cDNA analysis within the hippocampus.

    Science.gov (United States)

    Ginsberg, Stephen D; Che, Shaoli

    2004-08-01

    The use of five histochemical stains (cresyl violet, thionin, hematoxylin & eosin, silver stain, and acridine orange) was evaluated in combination with an expression profiling paradigm that included regional and single cell analyses within the hippocampus of post-mortem human brains and adult mice. Adjacent serial sections of human and mouse hippocampus were labeled by histochemistry or neurofilament immunocytochemistry. These tissue sections were used as starting material for regional and single cell microdissection followed by a newly developed RNA amplification procedure (terminal continuation (TC) RNA amplification) and subsequent hybridization to custom-designed cDNA arrays. Results indicated equivalent levels of global hybridization signal intensity and relative expression levels for individual genes for hippocampi stained by cresyl violet, thionin, and hematoxylin & eosin, and neurofilament immunocytochemistry. Moreover, no significant differences existed between the Nissl stains and neurofilament immunocytochemistry for individual CA1 neurons obtained via laser capture microdissection. In contrast, a marked decrement was observed in adjacent hippocampal sections stained for silver stain and acridine orange, both at the level of the regional dissection and at the CA1 neuron population level. Observations made on the cDNA array platform were validated by real-time qPCR using primers directed against beta-actin and glyceraldehyde-3 phosphate dehydrogenase. Thus, this report demonstrated the utility of using specific Nissl stains, but not stains that bind RNA species directly, in both human and mouse brain tissues at the regional and cellular level for state-of-the-art molecular fingerprinting studies.

  10. Inhibition and kinetic studies of lignin degrading enzymes of Ganoderma boninense by naturally occurring phenolic compounds.

    Science.gov (United States)

    Surendran, Arthy; Siddiqui, Yasmeen; Saud, Halimi Mohd; Ali, Nusaibah Syd; Manickam, Sivakumar

    2018-05-22

    Lignolytic (Lignin degrading) enzyme, from oil palm pathogen Ganoderma boninense Pat. (Syn G. orbiforme (Ryvarden), is involved in the detoxification and the degradation of lignin in the oil palm and is the rate-limiting step in the infection process of this fungus. Active inhibition of lignin degrading enzymes secreted by G. boninense by various naturally occurring phenolic compounds and estimation of efficiency on pathogen suppression was aimed at. In our work, ten naturally occurring phenolic compounds were evaluated for their inhibitory potential towards the lignolytic enzymes of G.boninense. Additionally, the lignin degrading enzymes were characterised. Most of the peholic compounds exhibited an uncompetitive inhibition towards the lignin degrading enzymes. Benzoic acid was the superior inhibitor to the production of lignin degrading enzymes, when compared between the ten phenolic compounds. The inhibitory potential of the phenolic compounds toward the lignin degrading enzymes are higher than that of the conventional metal ion inhibitor. The lignin degrading enzymes were stable in a wide range of pH but were sensitive to higher to temperature. The study demonstrated the inhibitor potential of ten naturally occurring phenolic compounds toward the lignin degrading enzymes of G. boninense with different efficacies. The study has shed a light towards a new management strategy to control BSR in oil palm. It serves as replacement for the existing chemical control. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  11. Highly efficient enzyme encapsulation in a protein nanocage: towards enzyme catalysis in a cellular nanocompartment mimic

    Science.gov (United States)

    Schoonen, Lise; Nolte, Roeland J. M.; van Hest, Jan C. M.

    2016-07-01

    The study of enzyme behavior in small nanocompartments is crucial for the understanding of biocatalytic processes in the cellular environment. We have developed an enzymatic conjugation strategy to attach a model enzyme to the interior of a cowpea chlorotic mottle virus capsid. It is shown that with this methodology high encapsulation efficiencies can be achieved. Additionally, we demonstrate that the encapsulation does not affect the enzyme performance in terms of a decreased activity or a hampered substrate diffusion. Finally, it is shown that the encapsulated enzymes are protected against proteases. We believe that our strategy can be used to study enzyme kinetics in an environment that approaches physiological conditions.The study of enzyme behavior in small nanocompartments is crucial for the understanding of biocatalytic processes in the cellular environment. We have developed an enzymatic conjugation strategy to attach a model enzyme to the interior of a cowpea chlorotic mottle virus capsid. It is shown that with this methodology high encapsulation efficiencies can be achieved. Additionally, we demonstrate that the encapsulation does not affect the enzyme performance in terms of a decreased activity or a hampered substrate diffusion. Finally, it is shown that the encapsulated enzymes are protected against proteases. We believe that our strategy can be used to study enzyme kinetics in an environment that approaches physiological conditions. Electronic supplementary information (ESI) available: Experimental procedures for the cloning, expression, and purification of all proteins, as well as supplementary figures and calculations. See DOI: 10.1039/c6nr04181g

  12. Inhibition study of alanine aminotransferase enzyme using sequential online capillary electrophoresis analysis.

    Science.gov (United States)

    Liu, Lina; Chen, Yuanfang; Yang, Li

    2014-12-15

    We report the study of several inhibitors on alanine aminotransferase (ALT) enzyme using sequential online capillary electrophoresis (CE) assay. Using metal ions (Na(+) and Mg(2+)) as example inhibitors, we show that evolution of the ALT inhibition reaction can be achieved by automatically and simultaneously monitoring the substrate consumption and product formation as a function of reaction time. The inhibition mechanism and kinetic constants of ALT inhibition with succinic acid and two traditional Chinese medicines were derived from the sequential online CE assay. Our study could provide valuable information about the inhibition reactions of ALT enzyme. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. The effects of storage on the retention of enzyme activity in cryostat sections. A quantitative histochemical study on rat liver

    NARCIS (Netherlands)

    Frederiks, W. M.; Ouwerkerk, I. J.; Bosch, K. S.; Marx, F.; Kooij, A.; van Noorden, C. J.

    1993-01-01

    The effect of storage of unfixed cryostat sections from rat liver for 4 h, 24 h, 3 days and 7 days at -25 degrees C was studied on the activities of lactate dehydrogenase, glucose-6-phosphate dehydrogenase, xanthine oxidoreductase, glutamate dehydrogenase, succinate dehydrogenase (all demonstrated

  14. Enzymes in Fermented Fish.

    Science.gov (United States)

    Giyatmi; Irianto, H E

    Fermented fish products are very popular particularly in Southeast Asian countries. These products have unique characteristics, especially in terms of aroma, flavor, and texture developing during fermentation process. Proteolytic enzymes have a main role in hydrolyzing protein into simpler compounds. Fermentation process of fish relies both on naturally occurring enzymes (in the muscle or the intestinal tract) as well as bacteria. Fermented fish products processed using the whole fish show a different characteristic compared to those prepared from headed and gutted fish. Endogenous enzymes like trypsin, chymotrypsin, elastase, and aminopeptidase are the most involved in the fermentation process. Muscle tissue enzymes like cathepsins, peptidases, transaminases, amidases, amino acid decarboxylases, glutamic dehydrogenases, and related enzymes may also play a role in fish fermentation. Due to the decreased bacterial number during fermentation, contribution of microbial enzymes to proteolysis may be expected prior to salting of fish. Commercial enzymes are supplemented during processing for specific purposes, such as quality improvement and process acceleration. In the case of fish sauce, efforts to accelerate fermentation process and to improve product quality have been studied by addition of enzymes such as papain, bromelain, trypsin, pepsin, and chymotrypsin. © 2017 Elsevier Inc. All rights reserved.

  15. Composition and distribution of cell wall phenolic compounds in flax (Linum usitatissimum L.) stem tissues

    NARCIS (Netherlands)

    Gorshkova, T.A.; Salnikov, V.V.; Pogodina, N.M.; Chemikosova, S.B.; Yablokova, E.V.; Ulanov, A.V.; Ageeva, M.V.; Dam, van J.E.G.; Lozovaya, V.V.

    2000-01-01

    Cell wall phenolic compounds were analysed in xylem and bast fibre-rich peels of flax stems by biochemical, histochemical and ultrastructural approaches. Localization of cell wall phenolics by the enzyme-gold method using laccase revealed several gold particle distribution patterns. One of the major

  16. Comparative histochemical study of Bowen’s disease and actinic keratosis: preserved normal basal cells in Bowen’s disease

    Directory of Open Access Journals (Sweden)

    H Ishida

    2009-12-01

    Full Text Available The degree of DNA-instability as revealed by immunohistochemical staining with anti-cytidine antibody after acid hydrolysis (DNA-instability test has been recently used as a marker of malignancy. This technique was applied to examine 17 skin tissue samples of Bowen’s disease, 47 of actinic keratosis, 15 of squamous cell carcinoma, 5 of seborrheic keratosis, and 10 of normal skin. All benign neoplastic cells of seborrheic keratosis and normal epidermal cells were negative. On the other hand, all cancer cells were positive with the DNA-instability test, indicating their malignancy, but all basal cells in Bowen’s disease were completely negative. Compatible with this result, the basal cells in Bowen’s disease were characteristically normal as evident in other histochemical examinations. Thus, they were negative with p53 immunohistochemistry, with normal signals of chromosome 17 in situ hybridisation and argyrophilic nucleolar organiser region, and showed slightly enhanced proliferative activity as revealed by proliferating cell nuclear antigen immunohistochemistry. Immunohistochemical staining with 34 ß E12 (monoclonal antibody against cytokeratins 1, 5, 10, and 14, which stains all normal epidermal keratinocytes including basal cells, showed that only the basal cells of Bowen’s disease stained strongly and homogeneously, while all cancer cells in the upper layers of Bowen’s disease and all layers of actinic keratosis were only sporadically or weakly stained. Staining with 34 ß B4 (monoclonal antibody against cytokeratin 1, which recognises the whole epidermis except for the basal layer in the normal epidermis, showed that the basal cells in the Bowen’s disease were completely negative, and lower layer cells in the actinic keratosis and upper layer cells in Bowen’s disease were only sporadically stained positive, although the superficial layer cells in actinic keratosis stained strongly and homogeneously. Our findings clearly

  17. Immuno-histochemical features of the structure of foetuses' uterine tubes from the mothers with pregnancy complications.

    Directory of Open Access Journals (Sweden)

    Larisa Kupriianova

    2017-01-01

    Full Text Available Material of the research includes uterine tubes of foetuses, that were dead on the gestational term between 21 and 41 weeks. According to peculiarities in the pregnancy course this material was divided into groups: foetuses from mothers with physiological pregnancy; foetuses from mothers. whose pregnancy takes its course on the background of the PE with different stages of the severity; and, finally, foetuses from mothers, whose pregnancy was complicated by the chronic infection of lower genital tracts. Research methods: macroscopic, histological, histochemical, immunohistochemical, morphometric, statistical. It was shown an excessive proliferation of the connective tissue in all structural components, in the composition of which prevails an immature collagen of the III type. It was also increased a production of the endothelin-1 by the vascular component of organs. In addition, it was defined an oppression of the functional activity of epithelial component by mucosa, which was expressed like decreasing of the hormonal activity of the the organ and increasing of the manifestation stage of apoptosis changes.

  18. A Historical Perspective on the Identification of Cell Types in Pancreatic Islets of Langerhans by Staining and Histochemical Techniques.

    Science.gov (United States)

    Baskin, Denis G

    2015-08-01

    Before the middle of the previous century, cell types of the pancreatic islets of Langerhans were identified primarily on the basis of their color reactions with histological dyes. At that time, the chemical basis for the staining properties of islet cells in relation to the identity, chemistry and structure of their hormones was not fully understood. Nevertheless, the definitive islet cell types that secrete glucagon, insulin, and somatostatin (A, B, and D cells, respectively) could reliably be differentiated from each other with staining protocols that involved variations of one or more tinctorial techniques, such as the Mallory-Heidenhain azan trichrome, chromium hematoxylin and phloxine, aldehyde fuchsin, and silver impregnation methods, which were popularly used until supplanted by immunohistochemical techniques. Before antibody-based staining methods, the most bona fide histochemical techniques for the identification of islet B cells were based on the detection of sulfhydryl and disulfide groups of insulin. The application of the classical islet tinctorial staining methods for pathophysiological studies and physiological experiments was fundamental to our understanding of islet architecture and the physiological roles of A and B cells in glucose regulation and diabetes. © The Author(s) 2015.

  19. Phage lytic enzymes: a history.

    Science.gov (United States)

    Trudil, David

    2015-02-01

    There are many recent studies regarding the efficacy of bacteriophage-related lytic enzymes: the enzymes of 'bacteria-eaters' or viruses that infect bacteria. By degrading the cell wall of the targeted bacteria, these lytic enzymes have been shown to efficiently lyse Gram-positive bacteria without affecting normal flora and non-related bacteria. Recent studies have suggested approaches for lysing Gram-negative bacteria as well (Briersa Y, et al., 2014). These enzymes include: phage-lysozyme, endolysin, lysozyme, lysin, phage lysin, phage lytic enzymes, phageassociated enzymes, enzybiotics, muralysin, muramidase, virolysin and designations such as Ply, PAE and others. Bacteriophages are viruses that kill bacteria, do not contribute to antimicrobial resistance, are easy to develop, inexpensive to manufacture and safe for humans, animals and the environment. The current focus on lytic enzymes has been on their use as anti-infectives in humans and more recently in agricultural research models. The initial translational application of lytic enzymes, however, was not associated with treating or preventing a specific disease but rather as an extraction method to be incorporated in a rapid bacterial detection assay (Bernstein D, 1997).The current review traces the translational history of phage lytic enzymes-from their initial discovery in 1986 for the rapid detection of group A streptococcus in clinical specimens to evolving applications in the detection and prevention of disease in humans and in agriculture.

  20. A virus-based single-enzyme nanoreactor

    NARCIS (Netherlands)

    Comellas Aragones, M.; Engelkamp, H.; Claessen, V.I.; Sommerdijk, N.A.J.M.; Rowan, A.E.; Christianen, P.C.M.; Maan, J.C.; Verduin, B.J.M.; Cornelissen, J.J.L.M.; Nolte, R.J.M.

    2007-01-01

    Most enzyme studies are carried out in bulk aqueous solution, at the so-called ensemble level, but more recently studies have appeared in which enzyme activity is measured at the level of a single molecule, revealing previously unseen properties. To this end, enzymes have been chemically or

  1. Enzyme-MOF (metal-organic framework) composites.

    Science.gov (United States)

    Lian, Xizhen; Fang, Yu; Joseph, Elizabeth; Wang, Qi; Li, Jialuo; Banerjee, Sayan; Lollar, Christina; Wang, Xuan; Zhou, Hong-Cai

    2017-06-06

    The ex vivo application of enzymes in various processes, especially via enzyme immobilization techniques, has been extensively studied in recent years in order to enhance the recyclability of enzymes, to minimize enzyme contamination in the product, and to explore novel horizons for enzymes in biomedical applications. Possessing remarkable amenability in structural design of the frameworks as well as almost unparalelled surface tunability, Metal-Organic Frameworks (MOFs) have been gaining popularity as candidates for enzyme immobilization platforms. Many MOF-enzyme composites have achieved unprecedented results, far outperforming free enzymes in many aspects. This review summarizes recent developments of MOF-enzyme composites with special emphasis on preparative techniques and the synergistic effects of enzymes and MOFs. The applications of MOF-enzyme composites, primarily in transferation, catalysis and sensing, are presented as well. The enhancement of enzymatic activity of the composites over free enzymes in biologically incompatible conditions is emphasized in many cases.

  2. Frictional amyloidosis in Oman - A study of ten cases

    Directory of Open Access Journals (Sweden)

    Mysore Venkataram

    2002-01-01

    Full Text Available Macular amyloidosis is an important cause for cutaneous pigmentation, the aetiology of which is poorly understood. Friction has recently been implicated the causation of early lesions, referred to as frictional amyloidosis. Confirmation of diagnosis by the detect on of amyloid using histochemical stains is inconsistent. Ten patients with pigmentation suggestive of macular amyloidosis were studied with detailed history, clinical examination, biopsy for histochemistry and electron microscopy. Nine out of ten patients had a history of prolonged friction with various objects such as bath sponges, brushes, towels, plant sticks and leaves. Amyloid was demonstrated by histochemical staining in only six out of ten cases. In the remaining four cases, amyloid was detected by electron microscopy. These consisted of aggregates of non-branching, extracellular, intertwining fibres measuring between 200-500 nm in length and between 20-25 nm in diameter. The study confirms the role of friction in the causation of this condition. Histochemical stains are not always successful in the detection of amyloid and electron microscopy is helpful for confirming its presence. The term frictional amyloidosis aptly describes the condition.

  3. Study of wettability of calcite surfaces using oil-brine-enzyme systems for enhanced oil recovery applications

    DEFF Research Database (Denmark)

    Khusainova, Alsu; Nielsen, Sidsel Marie; Pedersen, Hanne Høst

    2015-01-01

    and adhesion behaviour tests. Comparative studies with a surfactant, protein, purified enzyme, enzyme stabiliser using n-decane (as a model for the oil) have also been carried out in order to verify experimental results. The enzymes that have the highest effect on the wettability have been identified. Those...... action has been found to be replacement of oil at the solid surface by the enzyme. Other mechanisms (modification of the surface tension or catalytic modification of hydrocarbons resulting in reducing the oil viscosity) have shown to be much less pronounced from the measurements reported here....

  4. Enzyme Informatics

    Science.gov (United States)

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

    2012-01-01

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

  5. A study of overproduction and enhanced secretion of enzymes. Quarterly report

    Energy Technology Data Exchange (ETDEWEB)

    Dashek, W.V.

    1993-09-01

    Wood decay within forests, a significant renewable photosynthetic energy resource, is caused primarily by Basidiomycetous fungi, e.g., white rot fungi. These organisms possess the ability to degrade lignin, cellulose and hemicellulose, the main organic polymers of wood. In the case of the white rot fungi, e.g., Coriolus versicolor, the capacity results from the fungus` ability to elaborate extracellular cellulolytic and ligninolytic enzymes. With regard to the latter, at least one of the enzymes, polyphenol oxidase (PPO) appears within a defined growth medium. This proposal focuses on the over-production and enhanced secretion of PPO, cellulase and lignin peroxidase. There are two major sections to the proposal: (1) overproduction of lignocellulolytic enzymes by genetic engineering methodologies and hyper-production and enhanced secretion of these enzymes by biochemical/electro microscopical techniques and (2) the biochemical/electron microscopical method involves substrate induction and the time-dependent addition of respiration and PPO enzymes.

  6. Computer-based studies on enzyme catalysis : from structure to activity

    NARCIS (Netherlands)

    Ridder, L.O.

    2000-01-01

    Theoretical simulations are becoming increasingly important for our understanding of how enzymes work. The aim of the research presented in this thesis is to contribute to this development by applying various computational methods to three enzymes of theβ-ketoadipate pathway, and to

  7. Study on immobilization enzyme using radiation grafting and condensation covalent

    International Nuclear Information System (INIS)

    Cao Jin; Su Zongxian; Gao Jianfeng

    1989-01-01

    The immobilization of gluecose oxidase (GOD) on polyethylene and F 46 is described by radiation grafting and condensation covalent. The GOD on polyethylene film is characterized with IR-spectrum. The results show that the enzyme activity on F 46 film is high when dose rate and covalent yield are low. When covalent yield is 4.3% the enzyme relative activity achieves the greatest value for F 46 film. The experiment also demonstrates that acrylic acid affects the relative activity of enzyme and the method of IR-pectrum character is convenient and efficient for GOD on polyethylene film

  8. Enzyme stabilization for pesticide degradation

    Energy Technology Data Exchange (ETDEWEB)

    Rivers, D.B.; Frazer, F.R. III; Mason, D.W.; Tice, T.R.

    1988-01-01

    Enzymes offer inherent advantages and limitations as active components of formulations used to decontaminate soil and equipment contaminated with toxic materials such as pesticides. Because of the catalytic nature of enzymes, each molecule of enzyme has the potential to destroy countless molecules of a contaminating toxic compound. This degradation takes place under mild environmental conditions of pH, temperature, pressure, and solvent. The basic limitation of enzymes is their degree of stability during storage and application conditions. Stabilizing methods such as the use of additives, covalent crosslinking, covalent attachment, gel entrapment, and microencapsulation have been directed developing an enzyme preparation that is stable under extremes of pH, temperature, and exposure to organic solvents. Initial studies were conducted using the model enzymes subtilisin and horseradish peroxidase.

  9. An overview of technologies for immobilization of enzymes and surface analysis techniques for immobilized enzymes

    Science.gov (United States)

    Mohamad, Nur Royhaila; Marzuki, Nur Haziqah Che; Buang, Nor Aziah; Huyop, Fahrul; Wahab, Roswanira Abdul

    2015-01-01

    The current demands of sustainable green methodologies have increased the use of enzymatic technology in industrial processes. Employment of enzyme as biocatalysts offers the benefits of mild reaction conditions, biodegradability and catalytic efficiency. The harsh conditions of industrial processes, however, increase propensity of enzyme destabilization, shortening their industrial lifespan. Consequently, the technology of enzyme immobilization provides an effective means to circumvent these concerns by enhancing enzyme catalytic properties and also simplify downstream processing and improve operational stability. There are several techniques used to immobilize the enzymes onto supports which range from reversible physical adsorption and ionic linkages, to the irreversible stable covalent bonds. Such techniques produce immobilized enzymes of varying stability due to changes in the surface microenvironment and degree of multipoint attachment. Hence, it is mandatory to obtain information about the structure of the enzyme protein following interaction with the support surface as well as interactions of the enzymes with other proteins. Characterization technologies at the nanoscale level to study enzymes immobilized on surfaces are crucial to obtain valuable qualitative and quantitative information, including morphological visualization of the immobilized enzymes. These technologies are pertinent to assess efficacy of an immobilization technique and development of future enzyme immobilization strategies. PMID:26019635

  10. Histochemical Comparison of the Hypopharyngeal Gland in Apis cerana Fabricius, 1793 Workers and Apis mellifera Linnaeus, 1758 Workers

    Directory of Open Access Journals (Sweden)

    Guntima Suwannapong

    2010-01-01

    Full Text Available Hypopharyngeal glands of honeybee are age-dependent structures that change with the size of acini and are correlated with various social behaviors. The histochemical structure of Apis cerana and A. mellifera worker hypopharyngeal glands in four different developmental stages wes stained with ninhydrin Schiff's and periodic acid Schiff's reagents (PAS for localization of proteins and carbohydrates, respectively, and examined with light microscopy. Nurse bees of both honeybee species had significantly larger glands as compared to guards and forgers, but there were no statistically significant differences between these two species after accounting for caste. Gland protein concentration increased progressively in nurse bees, and this was correlated with the appearance of enriched protein granules in the cytoplasm. In addition, the hypopharyngeal gland protein concentration of A. mellifera was higher than that of A. cerana even though gland size was not significantly different between species. However, gland size was shown to have decreased progressively in foragers and guards.

  11. Characterising Complex Enzyme Reaction Data.

    Directory of Open Access Journals (Sweden)

    Handan Melike Dönertaş

    Full Text Available The relationship between enzyme-catalysed reactions and the Enzyme Commission (EC number, the widely accepted classification scheme used to characterise enzyme activity, is complex and with the rapid increase in our knowledge of the reactions catalysed by enzymes needs revisiting. We present a manual and computational analysis to investigate this complexity and found that almost one-third of all known EC numbers are linked to more than one reaction in the secondary reaction databases (e.g., KEGG. Although this complexity is often resolved by defining generic, alternative and partial reactions, we have also found individual EC numbers with more than one reaction catalysing different types of bond changes. This analysis adds a new dimension to our understanding of enzyme function and might be useful for the accurate annotation of the function of enzymes and to study the changes in enzyme function during evolution.

  12. Computational studies of radiation and oxidative damage to DNA and its recognition by repair enzyme

    Energy Technology Data Exchange (ETDEWEB)

    Pinak, M. [Center for Promotion of Computational Science and Engineering, Tokai Research Establishment, Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan)

    2000-03-01

    Molecular dynamics (MD) simulation is used to study the time evolution of the recognition processes and to construct a model of the specific DNA-repair enzyme' complexes. MD simulations of the following molecules were performed: DNA dodecamer with thymine dimer (TD), DNA 30-mer with thymine glycol (TG), and respective specific repair enzymes T4 Endonuclease V and Endonuclease III. Both DNA lesions are experimentally suggested to be mutagenic and carcinogenic unless properly recognized and repaired by repair enzymes. In the case of TD, there is detected a strong kink around the TD site, that is not observed in native DNA. In addition there is observed a different value of electrostatic energy at the TD site - negative '-9 kcal/mol', in contrast to the nearly neutral value of the native thymine site. These two factors - structural changes and specific electrostatic energy - seem to be important for proper recognition of a TD damaged site and for formation of DNA-enzyme complex. Formation of this complex is the onset of the repair of DNA. In the case of TG damaged DNA the structural characteristics of the TG were calculated (charges, bond lengths, bond angles, etc.). The formed TG was used to replace the native thymine and then submitted to the simulation in the system with a repair enzyme with Endonuclease III for the purpose of the study of the formation of the DNA-enzyme complex. (author)

  13. Caracterização morfoanatômica e histoquímica de Cuphea carthagenensis (Jacq. J.f. Macbr. (Lythraceae Morphological, anatomical and histochemical characterization of Cuphea carthagenensis (Jacq. J.F. Macbr. (Lythraceae

    Directory of Open Access Journals (Sweden)

    Makeli Garibotti Lusa

    2011-06-01

    Full Text Available Cuphea carthagenensis (Jacq. J.F. Macbr. é uma planta herbácea, que ocorre preferivelmente em locais úmidos. Dentre outras espécies do gênero, esta se destaca pelo grande potencial químico e emprego frequente na medicina popular. Neste estudo, descrevem-se aspectos morfológicos, a anatomia e as características histoquímicas dos órgãos vegetativos, na fase de desenvolvimento em que a espécie é comercializada. A partir de plantas adultas, foram coletadas amostras de raiz, caule e folhas. Esse material foi processado para análise anatômica e histoquímica em microscopia de luz e para análise morfológica, em microscopia eletrônica de varredura. Considerações morfoanatômicas importantes foram acrescentadas para C. carthagenensis, tais como: a ocorrência de felema aerenquimatoso com camadas suberificadas; a identificação dos tipos de tricomas ocorrentes nos órgãos vegetativos; e a caracterização do tricoma secretor, bem como do material secretado. Os grupos de metabólitos secundários presentes nos tecidos da raiz, do caule e da folha de C. carthagenensis que apresentaram reação histoquímica mais intensa foram: proantocianidinas, compostos fenólicos, polissacarídeos ácidos (especialmente mucilagem e lipídios totais.Cuphea carthagenensis (Jacq. J.F. Macbr. is an herb, which occurs preferably in wet places. Amongst other species of the genus, C. carthagenensis is distinguished for its great chemical potential and frequent use in popular medicine. In this study the morphological and anatomical structures were identified, as well as the histochemical characterization was done. Samples of root, stem and leaves were collected from adult plants. This material was processed for anatomical and histochemical analysis in light microscopy and for morphological analysis, in scanning electron microscopy. Important morphological and anatomical considerations were added for C. carthagenensis, such as: the occurrence of

  14. Thermodynamics of Enzyme-Catalyzed Reactions Database

    Science.gov (United States)

    SRD 74 Thermodynamics of Enzyme-Catalyzed Reactions Database (Web, free access)   The Thermodynamics of Enzyme-Catalyzed Reactions Database contains thermodynamic data on enzyme-catalyzed reactions that have been recently published in the Journal of Physical and Chemical Reference Data (JPCRD). For each reaction the following information is provided: the reference for the data, the reaction studied, the name of the enzyme used and its Enzyme Commission number, the method of measurement, the data and an evaluation thereof.

  15. Preliminary study on isolation and quality analysis of enzymes from fermented oil palm empty fruit bunch

    International Nuclear Information System (INIS)

    Mat Rasol Awang; Tamikazu Kume; Shinpei Matsuhashi

    1998-01-01

    Palm Empty Fruit Bunch (EFB) is a cellulosic waste, consisting of 40 - 60 % cellulose with the remaining components comprised of hemicellulose, lignin and other materials. Cellulase is a complex of enzymes containing chiefly endo and exo glucanase, as well as cellobiase plus others (Mandel et al, 1976). Studies on cellulase production from Trichodermaa viride have been reported. The enzyme system from this fungi is considered to be a complete composition of cellulase; and it was reported to be able to hydrolyse slowly a more resistant or crystalline portion of cellulose. Previous work showed Pleorotus sajor-caju and Coprinus cinereus can be easily grown on EFB. The quality of this enzyme system was characterized based on its degradation activity on filter paper, salicin and xylan into simple sugars. These activity tests would revealed the ability of cellulase enzyme system to break down insoluble cellulose, and hydrolysing salicin such as cellobiose and xylanase for breaking down hemicellulose. In this study, the enzyme system derived from liquid state fermentation by these fungi utilizing EFB as carbon source was investigated

  16. Immobilization of enzymes using non-ionic colloidal liquid aphrons (CLAs): Surface and enzyme effects.

    Science.gov (United States)

    Ward, Keeran; Xi, Jingshu; Stuckey, David C

    2015-12-01

    The use of non-ionic colloidal liquid aphrons (CLAs) as a support for enzyme immobilisation was investigated. Formulation required the mixing of an aqueous-surfactant solution with a relatively non-polar solvent-surfactant solution, forming a solvent droplet surrounded by a thin stabilised aqueous film (soapy shell). Studies utilising anionic surfactants have showed increased retention, however, very little have been understood about the forces governing immobilisation. This study seeks to determine the effects of enzyme properties on CLA immobilisation by examining a non-ionic/non-polar solvent system comprised of two non-ionic surfactants, Tween 20 and 80, mineral oil and the enzymes lipase, aprotinin and α-chymotrypsin. From these results it was deduced that hydrophobic interactions strongly governed immobilisation. Confocal Scanning Laser Microscopy (CSLM) revealed that immobilisation was predominantly achieved by surface adsorption attributed to hydrophobic interactions between the enzyme and the CLA surface. Enzyme surface affinity was found to increase when added directly to the formulation (pre-manufacture addition), as opposed to the bulk continuous phase (post-manufacture addition), with α-chymotrypsin and aprotinin being the most perturbed, while lipase was relatively unaffected. The effect of zeta potential on immobilisation showed that enzymes adsorbed better closer to their pI, indicating that charge minimisation was necessary for immobilisation. Finally, the effect of increasing enzyme concentration in the aqueous phase resulted in an increase in adsorption for all enzymes due to cooperativity between protein molecules, with saturation occurring faster at higher adsorption rates. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Histochemical evidence for the relationship between peel damage and the accumulation of phenolic compounds in gamma-irradiated citrus fruit

    International Nuclear Information System (INIS)

    Riov, J.

    1975-01-01

    The first symptoms of radiation damage to citrus fruit were noted 24 to 48 hr after irradiation with 240 krad of gamma rays. At about the same time, radiation-damaged cells were observed in peel cross sections in the flavedo, the outer colored peel layers. The damaged cells were deformed and their protoplasts stained much darker with haematoxylin-safranin than protoplasts of intact cells. The cytoplasm in damaged cells either thickened at one side of the cell, sometimes filling up most of the cell space, or contracted into a small mass. Using several histochemical reagents, a considerable accumulation of phenolic compounds was found to occur in the damaged cells shortly after irradiation. No accumulation of phenolic compounds was observed in intact cells of irradiated fruit. It is suggested that the phenolic compounds which accumulate in flavedo cells following irradiation cause cell death and consequent peel necrosis (pitting). (author)

  18. The influence of carbon nanotubes on enzyme activity and structure: investigation of different immobilization procedures through enzyme kinetics and circular dichroism studies

    International Nuclear Information System (INIS)

    Cang-Rong, Jason Teng; Pastorin, Giorgia

    2009-01-01

    In the last decade, many environmental organizations have devoted their efforts to identifying renewable biosystems, which could provide sustainable fuels and thus enhance energy security. Amidst the myriad of possibilities, some biofuels make use of different types of waste biomasses, and enzymes are often employed to hydrolyze these biomasses and produce sugars that will be subsequently converted into ethanol. In this project, we aimed to bridge nanotechnology and biofuel production: here we report on the activity and structure of the enzyme amyloglucosidase (AMG), physically adsorbed or covalently immobilized onto single-walled carbon nanotubes (SWNTs) and multi-walled carbon nanotubes (MWNTs). In fact, carbon nanotubes (CNTs) present several properties that render them ideal support systems, without the diffusion limitations displayed by porous material and with the advantage of being further functionalizable at their surface. Chemical ligation was achieved both on oxidized nanotubes (via carbodiimide chemistry), as well as on amino-functionalized nanotubes (via periodate-oxidized AMG). Results showed that AMG retained a certain percentage of its specific activity for all enzyme-carbon nanotubes complexes prepared, with the physically adsorbed samples displaying better catalytic efficiency than the covalently immobilized samples. Analysis of the enzyme's structure through circular dichroism (CD) spectroscopy revealed significant structural changes in all samples, the degree of change being consistent with the activity profiles. This study proves that AMG interacts differently with carbon nanotubes depending on the method employed. Due to the higher activity reported by the enzyme physically adsorbed onto CNTs, these samples demonstrated a vast potential for further development. At the same time, the possibility of inducing magnetic properties into CNTs offers the opportunity to easily separate them from the original solution. Hence, substances to which they

  19. Allosteric regulation of epigenetic modifying enzymes.

    Science.gov (United States)

    Zucconi, Beth E; Cole, Philip A

    2017-08-01

    Epigenetic enzymes including histone modifying enzymes are key regulators of gene expression in normal and disease processes. Many drug development strategies to target histone modifying enzymes have focused on ligands that bind to enzyme active sites, but allosteric pockets offer potentially attractive opportunities for therapeutic development. Recent biochemical studies have revealed roles for small molecule and peptide ligands binding outside of the active sites in modulating the catalytic activities of histone modifying enzymes. Here we highlight several examples of allosteric regulation of epigenetic enzymes and discuss the biological significance of these findings. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Profiling the orphan enzymes

    Science.gov (United States)

    2014-01-01

    The emergence of Next Generation Sequencing generates an incredible amount of sequence and great potential for new enzyme discovery. Despite this huge amount of data and the profusion of bioinformatic methods for function prediction, a large part of known enzyme activities is still lacking an associated protein sequence. These particular activities are called “orphan enzymes”. The present review proposes an update of previous surveys on orphan enzymes by mining the current content of public databases. While the percentage of orphan enzyme activities has decreased from 38% to 22% in ten years, there are still more than 1,000 orphans among the 5,000 entries of the Enzyme Commission (EC) classification. Taking into account all the reactions present in metabolic databases, this proportion dramatically increases to reach nearly 50% of orphans and many of them are not associated to a known pathway. We extended our survey to “local orphan enzymes” that are activities which have no representative sequence in a given clade, but have at least one in organisms belonging to other clades. We observe an important bias in Archaea and find that in general more than 30% of the EC activities have incomplete sequence information in at least one superkingdom. To estimate if candidate proteins for local orphans could be retrieved by homology search, we applied a simple strategy based on the PRIAM software and noticed that candidates may be proposed for an important fraction of local orphan enzymes. Finally, by studying relation between protein domains and catalyzed activities, it appears that newly discovered enzymes are mostly associated with already known enzyme domains. Thus, the exploration of the promiscuity and the multifunctional aspect of known enzyme families may solve part of the orphan enzyme issue. We conclude this review with a presentation of recent initiatives in finding proteins for orphan enzymes and in extending the enzyme world by the discovery of new

  1. Adsorption of monocomponent enzymes in enzyme mixture analyzed quantitatively during hydrolysis of lignocellulose substrates.

    Science.gov (United States)

    Várnai, Anikó; Viikari, Liisa; Marjamaa, Kaisa; Siika-aho, Matti

    2011-01-01

    The adsorption of purified Trichoderma reesei cellulases (TrCel7A, TrCel6A and TrCel5A) and xylanase TrXyn11 and Aspergillus niger β-glucosidase AnCel3A was studied in enzyme mixture during hydrolysis of two pretreated lignocellulosic materials, steam pretreated and catalytically delignified spruce, along with microcrystalline cellulose (Avicel). The enzyme mixture was compiled to resemble the composition of commercial cellulase preparations. The hydrolysis was carried out at 35 °C to mimic the temperature of the simultaneous saccharification and fermentation (SSF). Enzyme adsorption was followed by analyzing the activity and the protein amount of the individual free enzymes in the hydrolysis supernatant. Most enzymes adsorbed quickly at early stages of the hydrolysis and remained bound throughout the hydrolysis, although the conversion reached was fairly high. Only with the catalytically oxidized spruce samples, the bound enzymes started to be released as the hydrolysis degree reached 80%. The results based on enzyme activities and protein assay were in good accordance. Copyright © 2010 Elsevier Ltd. All rights reserved.

  2. X-ray absorption spectroscopic studies of mononuclear non-heme iron enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Westre, Tami E. [Stanford Univ., CA (United States)

    1996-01-01

    Fe-K-edge X-ray absorption spectroscopy (XAS) has been used to investigate the electronic and geometric structure of the iron active site in non-heme iron enzymes. A new theoretical extended X-ray absorption fine structure (EXAFS) analysis approach, called GNXAS, has been tested on data for iron model complexes to evaluate the utility and reliability of this new technique, especially with respect to the effects of multiple-scattering. In addition, a detailed analysis of the 1s→3d pre-edge feature has been developed as a tool for investigating the oxidation state, spin state, and geometry of iron sites. Edge and EXAFS analyses have then been applied to the study of non-heme iron enzyme active sites.

  3. Pancreatic Enzymes

    Science.gov (United States)

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

  4. Muscular sufficiency, serum protein, enzymes and bioenergetic studies in chronic malnutrition

    International Nuclear Information System (INIS)

    Gupta, R.K.; Mittal, R.D.; Agarwal, K.N.; Agarwal, D.K.

    1994-01-01

    Muscle sufficiency was significantly lower in 1336 children with chronic malnutrition of moderate to severe degree. 18 children with a chronic moderate degree of malnutrition and 8 well-nourished age-matched controls were selected for biochemical and 31-phosphorus magnetic resonance spectroscopy (31-P MRS) studies. The results shows that: a) serum total protein, albumin, iron, calcium and inorganic phosphate were similar in both groups; b) serum enzyme levels were significantly increased in the malnuourished group; c) 31-P MRS showed significantly higher means for total ATP, β-ATP, α-ATP and inorganic phosphate for the malnourished compared to the control group. In chronic malnutrition, proteins are maintained by degradation in muscle resulting in release of amino acids and enzymes. 31-P MRS studies showing increases in total ATP, β-ATP and inorganic phosphate and a decrease in phosphocreatine suggest that ATP is maintained at the cost of phosphocreatine. 22 refs., 4 tabs. 1 fig

  5. Effect of bleaching on mercury release from amalgam fillings and antioxidant enzyme activities: a pilot study.

    Science.gov (United States)

    Cakir, Filiz Yalcin; Ergin, Esra; Gurgan, Sevil; Sabuncuoglu, Suna; Arpa, Cigdem Sahin; Tokgoz, İlknur; Ozgunes, Hilal; Kiremitci, Arlin

    2015-01-01

    The aim of this pilot clinical study was to determine the mercury release from amalgam fillings and antioxidant enzyme activities (Superoxide Dismutase [SOD] and Catalase[CAT] ) in body fluids after exposure to two different vital tooth bleaching systems. Twenty eight subjects with an average age of 25.6 years (18-41) having at least two but not more than four Class II amalgam fillings on each quadrant arch in the mouth participated in the study. Baseline concentrations of mercury levels in whole blood, urine, and saliva were measured by a Vapor Generation Accessory connected to an Atomic Absorption Spectrometer. Erythrocyte enzymes, SOD, and CAT activities in blood were determined kinetically. Subjects were randomly assigned to two groups of 14 volunteers. Group 1 was treated with an at-home bleaching system (Opalescence PF 35% Carbamide Peroxide, Ultradent), and Group 2 was treated with a chemically activated office bleaching system (Opalescence Xtra Boost 38% Hydrogen Peroxide, Ultradent) according to the manufacturer's recommendations. Twenty-four hours after bleaching treatments, concentrations of mercury and enzymes were remeasured. There were no significant differences on mercury levels in blood, urine, and saliva before and after bleaching treatments (p > 0.05). No differences were also found in the level of antioxidant enzyme activities (SOD and CAT) before and after treatments (p > 0.05). Mercury release did not affect the enzyme activities (p > 0.05). Bleaching treatments either office or home did not affect the amount of mercury released from amalgam fillings in blood, urine, and saliva and the antioxidant-enzyme activities in blood. Bleaching treatments with the systems tested in this pilot study have no deleterious effect on the mercury release from amalgam fillings and antioxidant enzymes in body fluids. © 2014 Wiley Periodicals, Inc.

  6. Porcine intestinal mast cells. Evaluation of different fixatives for histochemical staining techniques considering tissue shrinkage

    Directory of Open Access Journals (Sweden)

    J. Rieger

    2013-07-01

    Full Text Available Staining of mast cells (MCs, including porcine ones, is critically dependent upon the fixation and staining technique. In the pig, mucosal and submucosal MCs do not stain or stain only faintly after formalin fixation. Some fixation methods are particularly recommended for MC staining, for example the fixation with Carnoy or lead salts. Zinc salt fixation (ZSF has been reported to work excellently for the preservation of fixation-sensitive antigens. The aim of this study was to establish a reliable histological method for counting of MCs in the porcine intestinum. For this purpose, different tissue fixation and staining methods that also allow potential subsequent immunohistochemical investigations were evaluated in the porcine mucosa, as well as submucosa of small and large intestine. Tissues were fixed in Carnoy, lead acetate, lead nitrate, Zamboni and ZSF and stained subsequently with either polychromatic methylene blue, alcian blue or toluidine blue. For the first time our study reveals that ZSF, a heavy metal fixative, preserves metachromatic staining of porcine MCs. Zamboni fixation was not suitable for histochemical visualization of MCs in the pig intestine. All other tested fixatives were suitable. Alcian blue and toluidine blue co-stained intestinal goblet cells which made a prima facie identification of MCs difficult. The polychromatic methylene blue proved to be the optimal staining. In order to compare MC counting results of the different fixation methods, tissue shrinkage was taken into account. As even the same fixation caused shrinkage-differences between tissue from small and large intestine, different factors for each single fixation and intestinal localization had to be calculated. Tissue shrinkage varied between 19% and 57%, the highest tissue shrinkage was found after fixation with ZSF in the large intestine, the lowest one in the small intestine after lead acetate fixation. Our study emphasizes that MC counting results from

  7. Early morphological and histochemical alterations in rats subjected to ileocystoplasty Alterações morfológicas e histoquímicas precoces em ratos submetidos à ileocistoplastia

    Directory of Open Access Journals (Sweden)

    Edinaldo Gonçalves de Miranda

    2009-10-01

    Full Text Available PURPOSE: To study morphologic and histochemical alterations arising at the ileocystoplasty site. METHODS: Sixteen Wistar female rats were subjected to ileocystoplasty and sacrificed after eight weeks. Material collected was divided into four groups for histological and histochemical studies: Group I (control - isolated ileum segment removed during ileocystoplasty; Group II - ileoileal anastomosis; Group III - ileovesical anastomosis and Group IV - ileal segment from the neobladder. Histological and histochemical study assessed dysplasia, metaplasia, acute and chronic inflammation, fibrosis, atrophy, hypertrophy, total mucins, sialomucins and sulfomucins. The non-parametric Wilcoxon and Mann-Whitney tests were employed in statistical analysis. RESULTS: None of the groups presented dysplasia. Acute inflammation and atrophy occurred in Groups II, III and IV, not reaching statistical significance. Metaplasia was significant only in Group III (p=0.012. Chronic inflammation, fibrosis and hypertrophy were significant in Groups II, III and IV. There was a significant increase in total mucin content in Group IV (p=0.014 and a reduction in Group III (p=0.016. Increases in sialomucins were observed in samples for Groups III (p=0.003 and IV (p=0.002 along with reduced sulfomucins in samples from Groups III (p=0.013 and IV (p=0.008. CONCLUSION: Ileocystoplasty in female rats caused squamous metaplasia, chronic inflammatory infiltration, fibrosis, hypertrophy, increase in sialomucin content, reduction in sulfomucins, and alterations in total mucin content with statistical significance, as well acute inflammatory infiltration and muscular atrophy with less intensity.OBJETIVO: Estudar alterações morfológicas e histoquímicas nas ileocistoplastias em ratos fêmea. MÉTODOS: 16 ratos fêmea foram submetidos à ileocistoplastia, sacrificadas após oito semanas. O material coletado foi e dividido em quatro grupos para análise morfológica e histoquímica: Grupo

  8. An in vitro assay to study the recruitment and substrate specificity of chromatin modifying enzymes

    Directory of Open Access Journals (Sweden)

    Vermeulen Michiel

    2004-01-01

    Full Text Available Post-translational modifications of core histones play an important role in regulating fundamental biological processes such as DNA repair, transcription and replication. In this paper, we describe a novel assay that allows sequential targeting of distinct histone modifying enzymes to immobilized nucleosomal templates using recombinant chimeric targeting molecules. The assay can be used to study the histone substrate specificity of chromatin modifying enzymes as well as whether and how certain enzymes affect each other's histone modifying activities. As such the assay can help to understand how a certain histone code is established and interpreted.

  9. Enzymes in biogenesis of plant cell wall polysaccharides. Enzyme characterization using tracer techniques

    International Nuclear Information System (INIS)

    Dickinson, D.B.

    1975-01-01

    Enzymes and metabolic pathways, by which starch and cell wall polysaccharides are formed, were investigated in order to learn how these processes are regulated and to identify the enzymatic regulatory mechanisms involved. Germinating lily pollen was used for studies of cell wall formation, and pollen and maize endosperm for studies of starch biosynthesis. Hexokinase being the first step in conversion of hexoses to starch, wall polysaccharides and respiratory substrates, maize endosperm enzyme was assayed by its conversion of 14 C-hexose to 14 C-hexose-6-P, and rapid separation of the two labelled compounds on anion-exchange paper. This enzyme did not appear to be under tight regulation by feed-back inhibition or activation, nor to be severely inhibited by glucose-6-P or activated by citrate. ADP-glucose pyrophosphorylase and other pyrophosphorylases were assayed radiochemically with 14 C-glucose-1-P (forward direction) or 32-PPsub(i) (reverse direction). They showed that the maize endosperm enzyme was activated by the glycolytic intermediates fructose-6-P and 3-phosphoglycerate, and that low levels of the enzyme were present in the high sucrose-low starch mutant named shrunken-2. Under optimal in-vitro assay conditions, the pollen enzyme reacted four times faster than the observed in-vivo rate of starch accumulation. Biogenesis of plant cell wall polysaccharides requires the conversion of hexose phosphates to various sugar nucleotides and utilization of the latter by the appropriate polysaccharide synthetases. Lily pollen possesses a β-1,3-glucan synthetase which is activated up to six-fold by β-linked oligosaccharides. Hence, the in-vivo activity of this enzyme may be modulated by such effector molecules

  10. Zymography methods for visualizing hydrolytic enzymes

    OpenAIRE

    Vandooren, Jennifer; Geurts, Nathalie; Martens, Erik; Van den Steen, Philippe E.; Opdenakker, Ghislain

    2013-01-01

    Zymography is a technique for studying hydrolytic enzymes on the basis of substrate degradation. It is a powerful., but often misinterpreted, tool. yielding information on potential. hydrolytic activities, enzyme forms and the locations of active enzymes. In this Review, zymography techniques are compared in terms of advantages, limitations and interpretations. With in gel zymography, enzyme forms are visualized according to their molecular weights. Proteolytic activities are localized in tis...

  11. Salt tolerance and activity of antioxidative enzymes of transgenic finger millet overexpressing a vacuolar H(+)-pyrophosphatase gene (SbVPPase) from Sorghum bicolor.

    Science.gov (United States)

    Anjaneyulu, Ediga; Reddy, Palle Surender; Sunita, Merla Srilakshmi; Kishor, Polavarapu B Kavi; Meriga, Balaji

    2014-06-15

    A vacuolar proton pyrophosphatase cDNA clone was isolated from Sorghum bicolor (SbVPPase) using end-to-end gene-specific primer amplification. It showed 80-90% homology at the nucleotide and 85-95% homology at the amino acid level with other VPPases. The gene was introduced into expression vector pCAMBIA1301 under the control of the cauliflower mosaic virus 35S (CaMV35S) promoter and transformed into Agrobacterium tumifaciens strain LBA4404 to infect embryogenic calli of finger millet (Eleusine coracana). Successful transfer of SbVPPase was confirmed by a GUS histochemical assay and PCR analysis. Both, controls and transgenic plants were subjected to 100 and 200mM NaCl and certain biochemical and physiological parameters were studied. Relative water content (RWC), plant height, leaf expansion, finger length and width and grain weight were severely reduced (50-70%), and the flowering period was delayed by 20% in control plants compared to transgenic plants under salinity stress. With increasing salt stress, the proline and chlorophyll contents as well as the enzyme activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (GPX) and glutathione reductase (GR) increased by 25-100% in transgenics, while malondialdehyde (MDA) showed a 2-4-fold decrease. The increased activities of antioxidant enzymes and the reduction in the MDA content suggest efficient scavenging of reactive oxygen species (ROS) in transgenics and, as a consequence, probably alleviation of salt stress. Also, the leaf tissues of the transgenics accumulated 1.5-2.5-fold higher Na(+) and 0.4-0.8-fold higher K(+) levels. Together, these results clearly demonstrate that overexpression of SbVPPase in transgenic finger millet enhances the plant's performance under salt stress. Copyright © 2014 Elsevier GmbH. All rights reserved.

  12. Magnetic cross-linked enzyme aggregates (CLEAs): a novel concept towards carrier free immobilization of lignocellulolytic enzymes.

    Science.gov (United States)

    Bhattacharya, Abhishek; Pletschke, Brett I

    2014-01-01

    The enzymatic conversion of lignocellulosic biomass into biofuels has been identified as an excellent strategy to generate clean energy. However, the current process is cost-intensive as an effective immobilization approach to reuse the enzyme(s) has been a major challenge. The present study introduces the concept and application of novel magnetic cross-linked enzyme aggregates (mag-CLEAs). Both mag-CLEAs and calcium-mag-CLEAs (Ca-mag-CLEAs) exhibited a 1.35 fold higher xylanase activity compared to the free enzyme and retained more than 80.0% and 90.0% activity, respectively, after 136h of incubation at 50°C, compared to 50% activity retained by CLEAs. A 7.4 and 9.0 fold higher sugar release from lime-pretreated and NH4OH pre-treated sugar bagasse, respectively, was achieved with Ca-mag-CLEAs compared to the free enzymes. The present study promotes the successful application of mag-CLEAs and Ca-mag-CLEAs as carrier free immobilized enzymes for the effective hydrolysis of lignocellulolytic biomass and associated biofuel feedstocks. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Radiation-induced histochemical and ultrastructural changes in the enterocytes in the rabbit

    Energy Technology Data Exchange (ETDEWEB)

    Cieciura, L; Bartel, H; Kaczmarek, B; Harazna, J [Wojskowa Akademia Medyczna, Lodz (Poland)

    1976-01-01

    Ultrastructural changes and enzyme activities in the cell organelles of rabbits were studied within 1, 3, 6, 9, 15 and 30 days of the irradiation with 550 rads of ..gamma..-radiation. Between the 1st and 3rd day after irradiation there was a fall in the succinate dehydrogenase activity in the swollen and frequently tigroidal mitochondria whose number distinctly diminished. By the 15th day these changes disappeared. In the hyaloplasm there was weakening of the reaction for lactate dehydrogenase after 1 day, and an increase in number of polysomes, glycogen granules and smooth vesicles after 3-9 days after irradiaton. The glucose-6-phosphatase activity was unchanged and so was the shape of the Golgi apparatus. The activity of lysosomal enzymes and the number of lysosomes in the experimental groups was approximately normal. By the 6th day the activity of alkaline phosphatase in the striated border was lowered, subsequently normal. On the whole, the intensity of postradiation changes in the intestinal mucosal epitelium is correlated with rhythm of proliferation and shedding of epithelial cells, although some signs of injury persists for longer time periods.

  14. Histochemical responses of rats exercised in two weekly frequencies and ingesting standard or hypercaloric diet

    Directory of Open Access Journals (Sweden)

    FI Freitas

    2009-07-01

    Full Text Available This study investigated if overfed rats present morphological and histochemical muscle adaptation similar to normally fed, both submitted to two different weekly frequencies of training. Thirty male Wistar rats were fed either with standard chow (SCØ or with hypercaloric diet (HCØ. They were subdivided into six subgroups: sedentary (SCØ and HCØ, trained twice/week (SC2 and HC2 and trained five times/week (SC5 and HC5. The trained groups swam 60 min/day, during 10 weeks. Twenty four hours after the last training, samples of Gastrocnemius were excised and stained with HE, NADH-TR and m-ATPase, and the capillary density was calculated. Total heart mass (HM and the mass of atrium (AM, left (LV and right (RV ventricles were excised and weighted. The comparisons were made by ANOVA and by Covariance analysis, adjusting the variables by body weight. The results showed that the HCØ achieved higher BM, however, absolute HM did not differ post training. Irrespective of the diet, rats that were trained twice a week presented significantly greater increase in the AM. In general, the SC5 and HC5 groups showed higher HM, LV, RV, proportion of oxidative fibres and capillary density, compared to the sedentary and twice week trained groups. A higher proportion of injuries (splitting was noted in the HC2 and HC5 compared to SC2 and SC5. These results indicate that the frequency of training influenced the skeletal and heart adaptation and larger changes were observed in the 5x/week group, which ingested the standard diet. The 5x/week training groups also presented large amount of muscle fibres damage.

  15. Zymography methods for visualizing hydrolytic enzymes.

    Science.gov (United States)

    Vandooren, Jennifer; Geurts, Nathalie; Martens, Erik; Van den Steen, Philippe E; Opdenakker, Ghislain

    2013-03-01

    Zymography is a technique for studying hydrolytic enzymes on the basis of substrate degradation. It is a powerful, but often misinterpreted, tool yielding information on potential hydrolytic activities, enzyme forms and the locations of active enzymes. In this Review, zymography techniques are compared in terms of advantages, limitations and interpretations. With in gel zymography, enzyme forms are visualized according to their molecular weights. Proteolytic activities are localized in tissue sections with in situ zymography. In vivo zymography can pinpoint proteolytic activity to sites in an intact organism. Future development of novel substrate probes and improvement in detection and imaging methods will increase the applicability of zymography for (reverse) degradomics studies.

  16. Nanomaterials with enzyme-like characteristics (nanozymes): next-generation artificial enzymes.

    Science.gov (United States)

    Wei, Hui; Wang, Erkang

    2013-07-21

    Over the past few decades, researchers have established artificial enzymes as highly stable and low-cost alternatives to natural enzymes in a wide range of applications. A variety of materials including cyclodextrins, metal complexes, porphyrins, polymers, dendrimers and biomolecules have been extensively explored to mimic the structures and functions of naturally occurring enzymes. Recently, some nanomaterials have been found to exhibit unexpected enzyme-like activities, and great advances have been made in this area due to the tremendous progress in nano-research and the unique characteristics of nanomaterials. To highlight the progress in the field of nanomaterial-based artificial enzymes (nanozymes), this review discusses various nanomaterials that have been explored to mimic different kinds of enzymes. We cover their kinetics, mechanisms and applications in numerous fields, from biosensing and immunoassays, to stem cell growth and pollutant removal. We also summarize several approaches to tune the activities of nanozymes. Finally, we make comparisons between nanozymes and other catalytic materials (other artificial enzymes, natural enzymes, organic catalysts and nanomaterial-based catalysts) and address the current challenges and future directions (302 references).

  17. de novo computational enzyme design.

    Science.gov (United States)

    Zanghellini, Alexandre

    2014-10-01

    Recent advances in systems and synthetic biology as well as metabolic engineering are poised to transform industrial biotechnology by allowing us to design cell factories for the sustainable production of valuable fuels and chemicals. To deliver on their promises, such cell factories, as much as their brick-and-mortar counterparts, will require appropriate catalysts, especially for classes of reactions that are not known to be catalyzed by enzymes in natural organisms. A recently developed methodology, de novo computational enzyme design can be used to create enzymes catalyzing novel reactions. Here we review the different classes of chemical reactions for which active protein catalysts have been designed as well as the results of detailed biochemical and structural characterization studies. We also discuss how combining de novo computational enzyme design with more traditional protein engineering techniques can alleviate the shortcomings of state-of-the-art computational design techniques and create novel enzymes with catalytic proficiencies on par with natural enzymes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Radiation-induced alterations in succinate dehydrogenase activity in the muscle of pigeon

    International Nuclear Information System (INIS)

    Gadhia, P.K.; Shah, V.C.

    1983-01-01

    The histochemical changes in succinate dehydrogenase were investigated in pectoralis major muscle of pigeon exposed to sub-lethal dose (400 rad) of γ-irradiation. Biochemical study was also carried out after 200, 300 and 400 rad of irradiation. In the present study the overall decrease in enzyme activity could be due to the structural and/or functional damage to mitochondria after treatment of pigeon to different sub-lethal doses of γ-irradiation. The significance of these results has been discussed with special reference to oxidative metabolism. (author)

  19. A study on some enzymes in rice field fish as biomarkers for pesticide exposure

    International Nuclear Information System (INIS)

    Juzu Hayati Arshad; Mazlina Muhammad; Salmijah Surif; Abdul Manan Mat Jais

    2002-01-01

    A study was carried out on three enzymes in rice field fish which can be used as possible biomarkers for pesticide exposure. The results obtained showed that the activity of the enzyme EROD (ethoxyresorufin-o-deethylase) increased between 1.5-2.2 fold in snakehead or haruan (Channa striata) sampled from the pesticide polluted areas, particularly the recycled areas and only a slight increase in EROD activity in climbing perch or puyu (Anabas testudineus). Increase in the activity of carboxylesterase was also noted. The percentage inhibition of acety1cholinesterase ranges from 18.4%-57.4% and 2.5%-34.2% for Channa striata and Anabas testudineus, respectively. Generally, a higher percentage of acety1cholinesterase inhibition was noted for those fish sampled from the recycled areas. The noted changes in the activity of these enzymes suggest exposure of rice field fish to foreign compounds, possibly pesticides, which are known to induce EROD activity and inhibit acety1cholinesterase activity. Therefore it may be possible to use these enzymes as biomarkers for pesticide exposure. (Author)

  20. Aspectos histológicos e histoquímicos da cloaca feminina de Columba livia (Gmelin (Columbidae, Columbiformes Histological and histochemical aspects of female cloaca of Columba livia (Gmelin (Columbidae, Columbiforme

    Directory of Open Access Journals (Sweden)

    Maria Eloíza de Oliveira Teles

    2001-03-01

    Full Text Available The domestic dove Columba livia (Gmelin, 1789 is a species well adapted to Brazil and the study of its reproductive biology is part of a broad research project on birds. This essay describes the morphological aspects of the cloaca of female Columba livia, describing compartments lengthwise starting from the head such as the coprodeo, urodeo and proctodeo limited by mucosal folds. Each compartment of the cloaca presents its own morphological characteristics which differ one from the other in form, height and position of mucosal projections, kinds of tissues, presence and histological aspects of glands, presence of lymphonodus. The rectum opens into the coprodeo, the ureter opens into the oviduct and the cloacal sac opening into the proctodeo. Histochemical studies have shown the presence of glycoproteins in tissue cells and gland cells on the three segments of the cloaca.

  1. [Advances on enzymes and enzyme inhibitors research based on microfluidic devices].

    Science.gov (United States)

    Hou, Feng-Hua; Ye, Jian-Qing; Chen, Zuan-Guang; Cheng, Zhi-Yi

    2010-06-01

    With the continuous development in microfluidic fabrication technology, microfluidic analysis has evolved from a concept to one of research frontiers in last twenty years. The research of enzymes and enzyme inhibitors based on microfluidic devices has also made great progress. Microfluidic technology improved greatly the analytical performance of the research of enzymes and enzyme inhibitors by reducing the consumption of reagents, decreasing the analysis time, and developing automation. This review focuses on the development and classification of enzymes and enzyme inhibitors research based on microfluidic devices.

  2. Computational enzyme design: transitioning from catalytic proteins to enzymes.

    Science.gov (United States)

    Mak, Wai Shun; Siegel, Justin B

    2014-08-01

    The widespread interest in enzymes stem from their ability to catalyze chemical reactions under mild and ecologically friendly conditions with unparalleled catalytic proficiencies. While thousands of naturally occurring enzymes have been identified and characterized, there are still numerous important applications for which there are no biological catalysts capable of performing the desired chemical transformation. In order to engineer enzymes for which there is no natural starting point, efforts using a combination of quantum chemistry and force-field based protein molecular modeling have led to the design of novel proteins capable of catalyzing chemical reactions not catalyzed by naturally occurring enzymes. Here we discuss the current status and potential avenues to pursue as the field of computational enzyme design moves forward. Published by Elsevier Ltd.

  3. The mechanisms of Excited states in enzymes

    DEFF Research Database (Denmark)

    Petersen, Frederic Nicolas Rønne; Bohr, Henrik

    2010-01-01

    Enzyme catalysis is studied on the basis of excited state processes, which are of electronic, vibrational and thermal nature. The ways of achieving the excited state, such as photo-absorption and ligand binding, are discussed and exemplified by various cases of enzymes.......Enzyme catalysis is studied on the basis of excited state processes, which are of electronic, vibrational and thermal nature. The ways of achieving the excited state, such as photo-absorption and ligand binding, are discussed and exemplified by various cases of enzymes....

  4. Polar localization of plasma membrane Ca2+/Mg2+ ATPase correlates with the pattern of steady ionic currents in eggs of Lymnaea stagnalis and Bithynia tentaculata (Mollusca)

    OpenAIRE

    Zivkovic, Dana; Créton, Robbert; Zwaan, Gideon; Bruijn, Wim; Dohmen, M.René

    1990-01-01

    textabstractDuring extrusion of the first polar body in eggs of Lymnaea stagnalis and Bithynia tentaculata a localized Ca2+ /Mg2+ ATPase activity was detected, using Ando's enzyme-cytochemical method for electron microscopy [Ando et al. (1981) Acta Histochem Cytochem 14:705-726]. The enzyme activity was distributed in a polar fashion, along the cytoplasmic face of the plasma membrane. In the eggs of Lymnaea it was found only in the vegetal hemisphere, whereas in Bithynia eggs it was localized...

  5. Histological, histochemical and immunohistochemical assessment of the protective role of selenium against γ -radiation damage in rats salivary glands

    International Nuclear Information System (INIS)

    Ahmed, S.F.

    2008-01-01

    Ionizing radiation affects the biological tissues through either direct or indirect action. Both types of actions occur together when a charged particle passes through a cell and can cause cell damage by different mechanisms . Radiation protection is based on physical principles which aim at lowering the radiation exposure dose and subsequently the risk of radiation injury. As radiation injury to living cells is, to large extent, due to oxidative stresses, the present study was conducted in order to evaluate the radioprotective efficacy of selenium, a naturally occurring antoxidant nutrient, as a a free radical scavenger against γ- radiation damage in rats' salivary glands by histological, histochemical and immunohistochemical assessment. A total of 120 male albino rats were used in the present study. The rats were divided into 6 groups (20 rats each): Control group:- rats received neither radiation nor selenium. Group I :- rats were exposed to a single whole body γ -irradiation at dose of 4 gray(Gy). Group l l:- as group I, but with radiation dose of 6 Gy. Group lll:- rats were injected intraperitoneally by a daily dose of sodium selenite (15 μg./ kg.b.w. )for three weeks. Group IV:- rats were injected intraperitoneally by a daily dose of sodium selenite (15 μg./ kg.b.w.) for one week before exposure to gamma rays at dose of 4 Gy and two weeks after. Group V:- as group IV, but with radiation dose of 6 Gy.

  6. Application of liquid chromatography-electrospray ionization mass spectrometry for study of steroid-converting enzymes.

    Science.gov (United States)

    Miksík, Ivan; Mikulíková, Katerina; Pácha, Jirí; Kucka, Marek; Deyl, Zdenek

    2004-02-05

    A high-performance liquid chromatography-atmospheric pressure ionization-electrospray ionization mass spectrometry (HPLC-API-ESI-MS) method was developed for the analysis of steroids in a study of steroid-converting enzymes. Separations ware done on a Zorbax Eclipse XDB-C18 column (eluted with a linear methanol-water-acetic acid gradient) and identification of the steroids involved was done by API-ESI-MS using positive ion mode and extracted ion analysis. The applicability of the present method for studying steroid metabolism was proven in assaying two steroid-converting enzymes (20beta-hydroxysteroid dehydrogenase and 11beta-hydroxysteroid dehydrogenase) in various biological samples (rat and chicken intestine, chicken oviduct).

  7. Microbial and biochemical studies on phytase enzyme in some microorganisms

    International Nuclear Information System (INIS)

    Abdelbary, N.A.

    1997-01-01

    Mixed calcium and magnesium salts of phytic acid myoinositol hexa phosphoric acid are widely distributed in food stuffs of plant origin, they may bind essential proteins, phospholipids and microelements to form indigestible compounds. In this concern, destruction of phytic acid and its salts by different methods is very important, one of them is by using microbial phytase. This study aims to produce phytase enzyme from microorganisms and study the best conditions of production and purification and also the properties of the partially purified phytase. 22 figs., 29 tabs., 61 refs

  8. Toward mechanistic classification of enzyme functions.

    Science.gov (United States)

    Almonacid, Daniel E; Babbitt, Patricia C

    2011-06-01

    Classification of enzyme function should be quantitative, computationally accessible, and informed by sequences and structures to enable use of genomic information for functional inference and other applications. Large-scale studies have established that divergently evolved enzymes share conserved elements of structure and common mechanistic steps and that convergently evolved enzymes often converge to similar mechanisms too, suggesting that reaction mechanisms could be used to develop finer-grained functional descriptions than provided by the Enzyme Commission (EC) system currently in use. Here we describe how evolution informs these structure-function mappings and review the databases that store mechanisms of enzyme reactions along with recent developments to measure ligand and mechanistic similarities. Together, these provide a foundation for new classifications of enzyme function. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Production of Enzymes from Marine Actinobacteria.

    Science.gov (United States)

    Zhao, X Q; Xu, X N; Chen, L Y

    Marine actinobacteria are well recognized for their capabilities to produce valuable natural products, which have great potential for applications in medical, agricultural, and fine chemical industries. In addition to producing unique enzymes responsible for biosynthesis of natural products, many marine actinobacteria also produce hydrolytic enzymes which are able to degrade various biopolymers, such as cellulose, xylan, and chitin. These enzymes are important to produce biofuels and biochemicals of interest from renewable biomass. In this chapter, the recent reports of novel enzymes produced by marine actinobacteria are reviewed, and advanced technologies that can be applied to search for novel marine enzymes as well as for improved enzyme production by marine actinobacteria are summarized, which include ribosome engineering, genome mining, as well as synthetic biology studies. © 2016 Elsevier Inc. All rights reserved.

  10. Hepatic Enzyme Alterations in HIV Patients on Antiretroviral Therapy: A Case-Control Study in a Hospital Setting in Ghana.

    Science.gov (United States)

    Osakunor, Derick Nii Mensah; Obirikorang, Christian; Fianu, Vincent; Asare, Isaac; Dakorah, Mavis

    2015-01-01

    Diagnosing hepatic injury in HIV infection can be a herculean task for clinicians as several factors may be involved. In this study, we sought to determine the effects of antiretroviral therapy (ART) and disease progression on hepatic enzymes in HIV patients. A case-control study conducted from January to May 2014 at the Akwatia Government Hospital, Eastern region, Ghana, The study included 209 HIV patients on ART (designated HIV-ART) and 132 ART-naive HIV patients (designated HIV-Controls). Data gathered included demography, clinical history and results of blood tests for hepatic enzymes. We employed the Fisher's, Chi-square, unpaired t-test and Pearson's correlation in analysis, using GraphPad Prism and SPSS. A P value 0.05). There was a significant positive correlation between hepatic enzymes (ALP, ALT, AST and GGT) for both groups (p enzymes for both groups was small. Antiretroviral therapy amongst this population has minimal effects on hepatic enzymes and does not suggest modifications in therapy. Hepatic injury may occur in HIV, even in the absence of ART and other traditional factors. Monitoring of hepatic enzymes is still important in HIV patients.

  11. Artificial Enzymes, "Chemzymes"

    DEFF Research Database (Denmark)

    Bjerre, Jeannette; Rousseau, Cyril Andre Raphaël; Pedersen, Lavinia Georgeta M

    2008-01-01

    Enzymes have fascinated scientists since their discovery and, over some decades, one aim in organic chemistry has been the creation of molecules that mimic the active sites of enzymes and promote catalysis. Nevertheless, even today, there are relatively few examples of enzyme models that successf......Enzymes have fascinated scientists since their discovery and, over some decades, one aim in organic chemistry has been the creation of molecules that mimic the active sites of enzymes and promote catalysis. Nevertheless, even today, there are relatively few examples of enzyme models...... that successfully perform Michaelis-Menten catalysis under enzymatic conditions (i.e., aqueous medium, neutral pH, ambient temperature) and for those that do, very high rate accelerations are seldomly seen. This review will provide a brief summary of the recent developments in artificial enzymes, so called...... "Chemzymes", based on cyclodextrins and other molecules. Only the chemzymes that have shown enzyme-like activity that has been quantified by different methods will be mentioned. This review will summarize the work done in the field of artificial glycosidases, oxidases, epoxidases, and esterases, as well...

  12. Mechanisms of hepatocarcinogenesis

    International Nuclear Information System (INIS)

    Peraino, C.; Carnes, B.A.; Burcham, J.M.; Vesselinovitch, S.D.; Blomquist, J.A.; Ludeman, V.A.; Prapuolenis, A.M.; Russell, J.J.; Staffeldt, E.F.

    1985-01-01

    These tumorigenesis studies involve administering a single dose of a tumor initiator to newborn rats, then, beginning at weaning, the continual feeding of tumor promoters. Histochemical analysis of the liver reveals the early formation of small foci of liver cells with biochemical markers like those present in most liver tumors. This new treatment protocol has enhanced the ability of the liver system to detect environmental carcinogens and is facilitating the analysis of the critical changes in liver cells associated with the onset of neoplasia. Changes in enzyme synthesis rates, functional mRNA levels, and transcribable gene content associated with the responses of these enzymes to adaptive stimuli in normal liver were measured. 5 refs

  13. Measurement of enzyme activity.

    Science.gov (United States)

    Harris, T K; Keshwani, M M

    2009-01-01

    To study and understand the nature of living cells, scientists have continually employed traditional biochemical techniques aimed to fractionate and characterize a designated network of macromolecular components required to carry out a particular cellular function. At the most rudimentary level, cellular functions ultimately entail rapid chemical transformations that otherwise would not occur in the physiological environment of the cell. The term enzyme is used to singularly designate a macromolecular gene product that specifically and greatly enhances the rate of a chemical transformation. Purification and characterization of individual and collective groups of enzymes has been and will remain essential toward advancement of the molecular biological sciences; and developing and utilizing enzyme reaction assays is central to this mission. First, basic kinetic principles are described for understanding chemical reaction rates and the catalytic effects of enzymes on such rates. Then, a number of methods are described for measuring enzyme-catalyzed reaction rates, which mainly differ with regard to techniques used to detect and quantify concentration changes of given reactants or products. Finally, short commentary is given toward formulation of reaction mixtures used to measure enzyme activity. Whereas a comprehensive treatment of enzymatic reaction assays is not within the scope of this chapter, the very core principles that are presented should enable new researchers to better understand the logic and utility of any given enzymatic assay that becomes of interest.

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

    DEFF Research Database (Denmark)

    Nekiunaite, Laura

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

  15. Engineering Cellulase Enzymes for Bioenergy

    Science.gov (United States)

    Atreya, Meera Elizabeth

    methods. Protein engineering targets to improve cellulases include reducing enzyme inhibition, improving inter-enzyme synergy, and increasing enzyme thermotolerance. Ameliorating enzyme inhibition could improve catalytic activity and thus the speed of conversion from biomass to fermentable sugars. Improved enzyme synergy could reduce the enzyme loading required to achieve equivalent biomass conversion. Finally, thermostable enzymes could enable more biomass to be processed at a time, due to high temperatures decreasing the viscosity of biomass slurries. A high-temperature enzyme saccharification reaction could also decrease the risk of contamination in the resulting concentrated sugar solution. Throughout my PhD, I have explored research projects broadly across all of these topics, with the most success in addressing the issue of enzyme inhibition. Cellulase enzyme Cel7A is the most abundant cellulase employed by natural systems for cellulose hydrolysis. Cellobiohydrolase enzymes like Cel7A break down cellulose into cellobiose (two glucose molecules). Unfortunately, upon cleavage, this product molecule interferes with continued hydrolysis activity of Cel7A; the strong binding of cellobiose in the active site can obstruct the enzyme from processing down the cellulase chain. This phenomenon, known as product inhibition, is a bottleneck to efficient biomass breakdown. Using insights from computational protein modeling studies, I experimentally generated and tested mutant Cel7A enzymes for improved tolerance to cellobiose. Indeed, this strategy yielded Cel7A enzymes exhibiting reduced product inhibition, including some mutants completely impervious to cellobiose. The improvements in tolerance to cellobiose, however, resulted in an overall reduction of enzyme activity for the mutants tested. Nevertheless, my findings substantiated computational reports with experimental evidence and pinpointed an amino acid residue in the Cel7A product binding site that is of interest for

  16. Consumer attitudes to enzymes in food production

    DEFF Research Database (Denmark)

    Søndergaard, Helle Alsted; Grunert, Klaus G.; Scholderer, Joachim

    2005-01-01

    The use of enzymes in food production has potential benefits for both food manufacturers and consumers. A central question is how consumers react to new ways of producing foods with enzymes. This study investigates the formation of consumer attitudes to different enzyme production methods in three...... European countries. Results show that consumers are most positive towards non-GM enzyme production methods. The enzyme production method is by far the most important factor for the formation of buying intentions compared to price and benefits. Results also show that environmental concern and attitudes...... to technological progress are the socio-political attitudes that have the highest predictive value regarding attitudes to enzyme production methods....

  17. Purification and characterization of extracellular amylolytic enzyme ...

    African Journals Online (AJOL)

    In the present study, the amylase enzyme producing potential of four different Aspergillus species was analyzed. The extracted amylase enzyme was purified by diethyl amino ethyl (DEAE) cellulose and Sephadex G-50 column chromatography and the enzyme activity was measured by using synthetic substrate starch.

  18. A Cytochemical Study of the Dehydrogenases of Mitochondria and Mitochondrial Particulates by a Monotetrazolium-Cobalt Chelation Method

    Science.gov (United States)

    Pearse, A. G. E.; Scarpelli, D. G.; Hess, R.

    1960-01-01

    In one of the current histochemical methods for dehydrogenases and diaphorases the final product is a metal-formazan dye derived from reduction of an N-thiazolyl-substituted tetrazolium. Sites of enzymic activity consistently appear as intramitochondrial dots 0.2 to 0.3 µ in diameter. When applied to active particles from disrupted mitochondria (Keilin-Hartree preparation, electron transport particle, Cooper-Lehninger particle) the individual particles appear as black dots 0.1 to 0.3 µ in diameter. It is clear that formazan is deposited progressively upon the particles and the results suggest that the latter may be spatially arranged in mitochondria so that areas of activity are separated by quiescent regions. PMID:14431240

  19. Digestive enzymes of some earthworms.

    Science.gov (United States)

    Mishra, P C; Dash, M C

    1980-10-15

    4 species of tropical earthworms differed with regard to enzyme activity. The maximum activity of protease and of cellulase occurred in the posterior region of the gut of the earthworms. On the average Octochaetona surensis shows maximum activity and Drawida calebi shows minimum activity for all the enzymes studied.

  20. Multi-enzyme Process Modeling

    DEFF Research Database (Denmark)

    Andrade Santacoloma, Paloma de Gracia

    are affected (in a positive or negative way) by the presence of the other enzymes and compounds in the media. In this thesis the concept of multi-enzyme in-pot term is adopted for processes that are carried out by the combination of enzymes in a single reactor and implemented at pilot or industrial scale...... features of the process and provides the information required to structure the process model by using a step-by-step procedure with the required tools and methods. In this way, this framework increases efficiency of the model development process with respect to time and resources needed (fast and effective....... In this way the model parameters that drives the main dynamic behavior can be identified and thus a better understanding of this type of processes. In order to develop, test and verify the methodology, three case studies were selected, specifically the bi-enzyme process for the production of lactobionic acid...

  1. Effect of low dose x irradiation on the succinate dehydrogenase activity of guinea pig, rat and mouse tissues

    Energy Technology Data Exchange (ETDEWEB)

    Shah, V C; Bhatavdekar, J M; Aravinda Babu, K [Gujarat Univ., Ahmedabad (India). Dept. of Zoology

    1976-07-01

    The histochemical changes in succinate dehydrogenase (SDH) were investigated in pectoralis major muscle of guinea pig, rat and mouse after level X-irradiation (72 R and 240 R) and compared with control animals. Biochemical studies were carried out on liver, kidney, muscle (pectoralis major), adrenal and spleen of these animals after low dose local X-irradiation and compared with control animals. Changes in SDH activity were studied up to 72-h post-irradiation, which shows that low dose local X-irradiation leads to increased enzymic activity. The increase in enzymic activity was remarkable in mouse tissues as compared with guinea pig and rat. Adrenals of all the three animals showed significant activation after all the doses of radiation studied. The significance of these results, with special reference to oxidative metabolism, has been discussed.

  2. Heavy enzymes--experimental and computational insights in enzyme dynamics.

    Science.gov (United States)

    Swiderek, Katarzyna; Ruiz-Pernía, J Javier; Moliner, Vicent; Tuñón, Iñaki

    2014-08-01

    The role of protein motions in the chemical step of enzyme-catalyzed reactions is the subject of an open debate in the scientific literature. The systematic use of isotopically substituted enzymes has been revealed as a useful tool to quantify the role of these motions. According to the Born-Oppenheimer approximation, changing the mass of the protein does not change the forces acting on the system but alters the frequencies of the protein motions, which in turn can affect the rate constant. Experimental and theoretical studies carried out in this field are presented in this article and discussed in the framework of Transition State Theory. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Flavourzyme, an Enzyme Preparation with Industrial Relevance: Automated Nine-Step Purification and Partial Characterization of Eight Enzymes.

    Science.gov (United States)

    Merz, Michael; Eisele, Thomas; Berends, Pieter; Appel, Daniel; Rabe, Swen; Blank, Imre; Stressler, Timo; Fischer, Lutz

    2015-06-17

    Flavourzyme is sold as a peptidase preparation from Aspergillus oryzae. The enzyme preparation is widely and diversely used for protein hydrolysis in industrial and research applications. However, detailed information about the composition of this mixture is still missing due to the complexity. The present study identified eight key enzymes by mass spectrometry and partially by activity staining on native polyacrylamide gels or gel zymography. The eight enzymes identified were two aminopeptidases, two dipeptidyl peptidases, three endopeptidases, and one α-amylase from the A. oryzae strain ATCC 42149/RIB 40 (yellow koji mold). Various specific marker substrates for these Flavourzyme enzymes were ascertained. An automated, time-saving nine-step protocol for the purification of all eight enzymes within 7 h was designed. Finally, the purified Flavourzyme enzymes were biochemically characterized with regard to pH and temperature profiles and molecular sizes.

  4. A Short History of the Hatching Enzyme Studies in Medaka(Development of Medaka Biology in Japan-Part II)

    OpenAIRE

    Yamagami, Kenjiro

    1997-01-01

    The studies on the hatching enzyme of the medaka, Oryzias latipes, have a history of about 50 years, which is only a half of whole history of the studies on the hatching enzyme in animals since the first conjecture of it in a lung fish in 1900. Medaka, however, has served as the material most intensively studied for the enzyme, and the studies have given invaluable information to establish some significant concepts in the field of developmental and cell biology as well as the hatching biology...

  5. Practical steady-state enzyme kinetics.

    Science.gov (United States)

    Lorsch, Jon R

    2014-01-01

    Enzymes are key components of most biological processes. Characterization of enzymes is therefore frequently required during the study of biological systems. Steady-state kinetics provides a simple and rapid means of assessing the substrate specificity of an enzyme. When combined with site-directed mutagenesis (see Site-Directed Mutagenesis), it can be used to probe the roles of particular amino acids in the enzyme in substrate recognition and catalysis. Effects of interaction partners and posttranslational modifications can also be assessed using steady-state kinetics. This overview explains the general principles of steady-state enzyme kinetics experiments in a practical, rather than theoretical, way. Any biochemistry textbook will have a section on the theory of Michaelis-Menten kinetics, including derivations of the relevant equations. No specific enzymatic assay is described here, although a method for monitoring product formation or substrate consumption over time (an assay) is required to perform the experiments described. © 2014 Elsevier Inc. All rights reserved.

  6. Enzyme detection by microfluidics

    DEFF Research Database (Denmark)

    2013-01-01

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

  7. Inhibition and kinetic studies of cellulose- and hemicellulose-degrading enzymes of Ganoderma boninense by naturally occurring phenolic compounds.

    Science.gov (United States)

    Surendran, A; Siddiqui, Y; Ali, N S; Manickam, S

    2018-06-01

    Ganoderma sp, the causal pathogen of the basal stem rot (BSR) disease of oil palm, secretes extracellular hydrolytic enzymes. These play an important role in the pathogenesis of BSR by nourishing the pathogen through the digestion of cellulose and hemicellulose of the host tissue. Active suppression of hydrolytic enzymes secreted by Ganoderma boninense by various naturally occurring phenolic compounds and estimation of their efficacy on pathogen suppression is focused in this study. Ten naturally occurring phenolic compounds were assessed for their inhibitory effect on the hydrolytic enzymes of G. boninense. The enzyme kinetics (V max and K m ) and the stability of the hydrolytic enzymes were also characterized. The selected compounds had shown inhibitory effect at various concentrations. Two types of inhibitions namely uncompetitive and noncompetitive were observed in the presence of phenolic compounds. Among all the phenolic compounds tested, benzoic acid was the most effective compound suppressive to the growth and production of hydrolytic enzymes secreted by G. boninense. The phenolic compounds as inhibitory agents can be a better replacement for the metal ions which are known as conventional inhibitors till date. The three hydrolytic enzymes were stable in a wide range of pH and temperature. These findings highlight the efficacy of the applications of phenolic compounds to control Ganoderma. The study has proved a replacement for chemical controls of G. boninense with naturally occurring phenolic compounds. © 2018 The Society for Applied Microbiology.

  8. Interactions of nitrite with catalase: Enzyme activity and reaction kinetics studies.

    Science.gov (United States)

    Krych-Madej, Justyna; Gebicka, Lidia

    2017-06-01

    Catalase, a heme enzyme, which catalyzes decomposition of hydrogen peroxide to water and molecular oxygen, is one of the main enzymes of the antioxidant defense system of the cell. Nitrite, used as a food preservative has long been regarded as a harmful compound due to its ability to form carcinogenic nitrosamines. Recently, much evidence has been presented that nitrite plays a protective role as a nitric oxide donor under hypoxic conditions. In this work the effect of nitrite on the catalytic reactions of catalase was studied. Catalase was inhibited by nitrite, and this process was pH-dependent. IC 50 values varied from about 1μM at pH5.0 to about 150μM of nitrite at pH7.4. The presence of chloride significantly enhanced nitrite-induced catalase inhibition, in agreement with earlier observations. The kinetics of the reactions of nitrite with ferric catalase, its redox intermediate, Compound I, and catalase inactive form, Compound II, was also studied. Possible mechanisms of nitrite-induced catalase inhibition are analyzed and the biological consequences of the reactions of catalase with nitrite are discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Thermometric enzyme linked immunosorbent assay: TELISA.

    Science.gov (United States)

    Mattiasson, B; Borrebaeck, C; Sanfridson, B; Mosbach, K

    1977-08-11

    A new method, thermometric enzyme linked immunosorbent assay (TELISA), for the assay of endogenous and exogenous compounds in biological fluids is described. It is based on the previously described enzyme linked immunosorbent assay technique, ELISA, but utilizes enzymic heat formation which is measured in an enzyme thermistor unit. In the model system studied determination of human serum albumin down to a concentration of 10(-10) M (5 ng/ml) was achieved, with both normal and catalase labelled human serum albumin competing for the binding sites on the immunosorbent, which was rabbit antihuman serum albumin immobilized onto Sepharose CL-4B.

  10. Histological and histochemical studies on the female reproductive system of rose-ringed parakeet (Psittacula krameri) after testosterone propionate treatment.

    Science.gov (United States)

    Sarker, A K; Seth, T N

    1975-01-01

    Intramuscular injections of testosterone propionate (Perandren, CIBA) at a dose level of 2.5 mg per day for 10 days into adult female parakeet caused an increment of differentiated follicles in the ovary. The histological study of the testosterone treated oviduct of the bird showed well developed villi with a significant number of tubular glands particularly in the middle and distal parts of the oviduct. The high level of alkaline phosphatase activity and ascorbic acid concentration in the distal part of the oviduct in treated birds probably increase the power of hatchable eggs which has a close relationship with the enzyme and vitamin C concentration in the uterus. The testosterone treatment causes a marked depletion of granulosal vitamins from ovary but augments the ascorbate mobilization in the thecal region to a very great extent probably due to more LH secretion from the pituitary.

  11. 7 CFR 58.436 - Rennet, pepsin, other milk clotting enzymes and flavor enzymes.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Rennet, pepsin, other milk clotting enzymes and flavor enzymes. 58.436 Section 58.436 Agriculture Regulations of the Department of Agriculture (Continued... clotting enzymes and flavor enzymes. Enzyme preparations used in the manufacture of cheese shall be safe...

  12. A framework and case studies for evaluation of enzyme ontogeny in children's health risk evaluation.

    Science.gov (United States)

    Ginsberg, Gary; Vulimiri, Suryanarayana V; Lin, Yu-Sheng; Kancherla, Jayaram; Foos, Brenda; Sonawane, Babasaheb

    2017-01-01

    Knowledge of the ontogeny of Phase I and Phase II metabolizing enzymes may be used to inform children's vulnerability based upon likely differences in internal dose from xenobiotic exposure. This might provide a qualitative assessment of toxicokinetic (TK) variability and uncertainty pertinent to early lifestages and help scope a more quantitative physiologically based toxicokinetic (PBTK) assessment. Although much is known regarding the ontogeny of metabolizing systems, this is not commonly utilized in scoping and problem formulation stage of human health risk evaluation. A framework is proposed for introducing this information into problem formulation which combines data on enzyme ontogeny and chemical-specific TK to explore potential child/adult differences in internal dose and whether such metabolic differences may be important factors in risk evaluation. The framework is illustrated with five case study chemicals, including some which are data rich and provide proof of concept, while others are data poor. Case studies for toluene and chlorpyrifos indicate potentially important child/adult TK differences while scoping for acetaminophen suggests enzyme ontogeny is unlikely to increase early-life risks. Scoping for trichloroethylene and aromatic amines indicates numerous ways that enzyme ontogeny may affect internal dose which necessitates further evaluation. PBTK modeling is a critical and feasible next step to further evaluate child-adult differences in internal dose for a number of these chemicals.

  13. Determination of the enzyme reaction rate in a differential fixed-bed reactor: a case study

    Directory of Open Access Journals (Sweden)

    Baruque Filho E.A.

    2001-01-01

    Full Text Available The reaction rate of starch hydrolysis catalyzed by a glucoamylase covalently bound to chitin particles was measured in a Differential Fixed-Bed Reactor (DFBR. Under selected test conditions the initial reaction rate may represent biocatalyst activity. Some aspects which influence measurement of the initial reaction rate of an immobilized enzyme were studied: the amount of desorbed enzyme and its hydrolytic activity, the extent of pore blockage of the biocatalyst caused by substrate solution impurities and the internal and external diffusional mass transfer effects. The results showed that the enzyme glucoamylase was firmly bound to the support, as indicated by the very low amount of desorbed protein found in the recirculating liquid. Although this protein was very active, its contribution to the overall reaction rate was negligible. It was observed that the biocatalyst pores were susceptible to being blocked by the impurities of the starch solution. This latter effect was accumulative, increasing with the number of sequential experiments carried out. When the substrate solution was filtered before use, very reliable determinations of immobilized enzyme reaction rates could be performed in the DFBR. External and internal diffusional resistences usually play a significant role in fixed-bed reactors. However, for the experimental system studied, internal mass transfer effects were not significant, and it was possible to select an operational condition (recirculation flow rate value that minimized the external diffusional limitations.

  14. Elevated Liver Enzymes

    Science.gov (United States)

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

  15. Stability of Enzymes in Granular Enzyme Products for Laundry Detergents

    DEFF Research Database (Denmark)

    Biran, Suzan; Bach, Poul; Simonsen, Ole

    Enzymes have long been of interest to the detergent industry due to their ability to improve the cleaning efficiency of synthetic detergents, contribute to shortening washing times, and reduce energy and water consumption, provision of environmentally friendlier wash water effluents and fabric care....... However, incorporating enzymes in detergent formulations gives rise to numerous practical problems due to their incompatibility with and stability against various detergent components. In powdered detergent formulations, these issues can be partly overcome by physically isolating the enzymes in separate...... particles. However, enzymes may loose a significant part of their activity over a time period of several weeks. Possible causes of inactivation of enzymes in a granule may be related to the release of hydrogen peroxide from the bleaching chemicals in a moisture-containing atmosphere, humidity, autolysis...

  16. In silico molecular docking studies of new potential 4-phthalazinyl-hydrazones on selected Trypanosoma cruzi and Leishmania enzyme targets.

    Science.gov (United States)

    Romero, Angel H; López, Simón E

    2017-09-01

    Recently, a series of 4-phthalazinyl-hydrazones under its E-configuration have exhibited excellent in vitro antichagasic and antileishmanial profiles. Preliminary assays on both parasites suggested that the most active derivatives act through oxidative and nitrosative stress mechanisms; however, their exact mode of actions as anti-trypanosomal and anti-leishmanial agents have not been completely elucidated. This motivated to perform a molecular docking study on essential trypanosomatid enzymes such as superoxide dismutase (SOD), trypanothione reductase (TryR), cysteine-protease (CP) and pteridine reductase 1 (PTR1). In addition, to understand the experimental results of nitric oxide production obtained for infected macrophages with Leishmania parasite, a molecular docking was evaluated on nitric oxide synthase (iNOS) enzyme of Rattus norvegicus. Both diastereomers (E and Z) of the 4-phthalazinyl-hydrazones were docked on the mentioned targets. In general, molecular docking on T. cruzi enzymes revealed that the E-diastereomers exhibited lower binding energies than Z-diastereomers on the Fe-SOD and CP enzymes, while Z-diastereomers showed lower docking energies than E-isomers on TryR enzyme. For the Leishmania docking studies, the Z-isomers exhibited the best binding affinities on the PTR1 and iNOS enzymes, while the TryR enzyme showed a minor dependence with the stereoselectivity of the tested phthalazines. However, either the structural information of the ligand-enzyme complexes or the experimental data suggest that the significant antitrypanosomatid activity of the most active derivatives is not associated to the inhibition of the SOD, CP and PTR1 enzymes, while the TryR inhibition and nitric oxide generation in host cells emerge as interesting antitrypanosomatid therapeutic targets. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Enzyme structure, enzyme function and allozyme diversity in ...

    African Journals Online (AJOL)

    In estimates of population genetic diversity based on allozyme heterozygosity, some enzymes are regularly more variable than others. Evolutionary theory suggests that functionally less important molecules, or parts of molecules, evolve more rapidly than more important ones; the latter enzymes should then theoretically be ...

  18. Epigenetics of dominance for enzyme activity

    Indian Academy of Sciences (India)

    Unknown

    dimer over a wide range of H+ concentrations accounts for the epigenetics of dominance for enzyme activity. [Trehan K S ... The present study has been carried on acid phosphatase .... enzyme activity over mid parent value (table 3, col. 13),.

  19. Comparing The Efficacy of Hematoxylin and Eosin, Periodic Acid Schiff and Fluorescent Periodic Acid Schiff-Acriflavine Techniques for Demonstration of Basement Membrane in Oral Lichen Planus: A Histochemical Study.

    Science.gov (United States)

    Pujar, Ashwini; Pereira, Treville; Tamgadge, Avinash; Bhalerao, Sudhir; Tamgadge, Sandhya

    2015-01-01

    Basement membrane (BM) is a thick sheet of extracellular matrix molecules, upon which epithelial cells attach. Various immunohistochemical studies in the past have been carried out but these advanced staining techniques are expensive and not feasible in routine laboratories. Although hematoxylin and eosin (H-E) is very popular among pathologists for looking at biopsies, the method has some limitations. This is where special stains come handy. The aim of the present study was to demonstrate and compare the efficacy of H-E, periodic acid Schiff (PAS) and fluorescent periodic acid-acriflavine staining techniques for the basement membrane and to establish a histochemical stain which could be cost effective, less time consuming, and unambiguous for observation of the basement membrane zone. A total number of 40 paraffin-embedded tissue sections of known basement membrane containing tissues including 10 - Normal oral mucosa (NOM) and 30 - oral lichen planus (OLP) were considered in the study. Four-micron-thick sections of each block were cut and stained with H-E stain, PAS and fluorescent periodic acid-acriflavine stain. Sections were evaluated by three oral pathologists independently for continuity, contrast and pattern. Though all the three stains showed favorable features at different levels, acriflavine stain was better than the other stains in demonstrating BM continuity, contrast and also the pattern followed by PAS stain. Acriflavine stain was the better in demonstrating a fibrillar pattern of a BM. Acriflavine stains a BM distinctly and is less time consuming and easy to carry out using readily available dyes as compared to other stains. The continuity and contrast along with the homogenous pattern and the afibrillar pattern of the BM was better demonstrated by acriflavine followed by the PAS stain.

  20. Comparing the efficacy of hematoxylin and eosin, periodic acid schiff and fluorescent periodic acid schiff-acriflavine techniques for demonstration of basement membrane in oral lichen planus: A histochemical study

    Directory of Open Access Journals (Sweden)

    Ashwini Pujar

    2015-01-01

    Full Text Available Background: Basement membrane (BM is a thick sheet of extracellular matrix molecules, upon which epithelial cells attach. Various immunohistochemical studies in the past have been carried out but these advanced staining techniques are expensive and not feasible in routine laboratories. Although hematoxylin and eosin (H-E is very popular among pathologists for looking at biopsies, the method has some limitations. This is where special stains come handy. Aims and Objectives: The aim of the present study was to demonstrate and compare the efficacy of H-E, periodic acid Schiff (PAS and fluorescent periodic acid-acriflavine staining techniques for the basement membrane and to establish a histochemical stain which could be cost effective, less time consuming, and unambiguous for observation of the basement membrane zone. Materials and Methods: A total number of 40 paraffin-embedded tissue sections of known basement membrane containing tissues including 10 - Normal oral mucosa (NOM and 30 - oral lichen planus (OLP were considered in the study. Four-micron-thick sections of each block were cut and stained with H-E stain, PAS and fluorescent periodic acid-acriflavine stain. Sections were evaluated by three oral pathologists independently for continuity, contrast and pattern. Results: Though all the three stains showed favorable features at different levels, acriflavine stain was better than the other stains in demonstrating BM continuity, contrast and also the pattern followed by PAS stain. Acriflavine stain was the better in demonstrating a fibrillar pattern of a BM. Acriflavine stains a BM distinctly and is less time consuming and easy to carry out using readily available dyes as compared to other stains. Conclusion: The continuity and contrast along with the homogenous pattern and the afibrillar pattern of the BM was better demonstrated by acriflavine followed by the PAS stain.

  1. Enzymes for Enhanced Oil Recovery (EOR)

    Energy Technology Data Exchange (ETDEWEB)

    Nasiri, Hamidreza

    2011-04-15

    enzymes on interactions in the oil/brine/solid system was studied. It was found that enzymes can change the adhesion behavior of the crude oil on glass surfaces from adhesion to non-adhesion when they are added to the brine solution. This was confirmed by contact angle measurements, which showed that contact angles became more water-wet (i.e. decreased) after exposure to enzyme solutions. Possible mechanisms giving rise to these observations, including catalysis of ester hydrolysis and enzyme adsorption, were discussed and tested. An experimental study of changes in oil-water interfacial properties by addition of enzymes and proteins, including measurements of interfacial tension and electrophoretic mobility, has been performed. It was found that the effect of enzymes on oil-water properties is minor compared to their effect on oil-water-solid properties. Their contribution to change interfacial tension between oil and water is not significant while they affect the electrophoretic mobility of emulsified oil in enzyme-brine solution to some extent. Attempts were also made to study changes in both oil and water phase composition after equilibration with enzymes. However, since the chemical composition of crude oil is highly complex, a model oil was used in some of the experiments. The model oil was chosen to be a water insoluble ester (ethyl decanoate) solved in mineral oil in an effort to verify the possible role of catalysis of ester hydrolysis. Dynamic core displacements using sandstone and carbonate rocks were conducted to show the potential of improved oil recovery by enzyme- and combined enzyme-surfactant flooding. Most of the core flooding experiments commenced with water flooding from initial water saturation, Swi, (established with synthetic sea water) which will be referred to as secondary mode displacements. Accordingly, tertiary oil recovery processes were used to describe injection of enzyme and/or enzyme-surfactant solutions from residual oil saturation, Sor

  2. Acute radiation proctitis. A clinical, histopathological and histochemical study

    International Nuclear Information System (INIS)

    Hovdenak, Nils

    2004-01-01

    The aim of the study is: 1) A sequential description of the clinical course of acute radiation proctitis during pelvic RT. 2) A sequential description of the rectal mucosal histopathology during pelvic RT as a possible substrate for clinical toxicity. 3) To assess the mucosal protease activity during RT as a possible explanation of the observed tissue changes. 4) To assess the efficacy of prophylactic sucralfate in acute radiation proctitis a randomised study was initiated and carried out together with a meta-analysis of previously available data. 5) Most studies on clinical acute toxicity in pelvic RT use either the RTOG/EORTC score system or focus on diarrhoea/stool frequency. A more differentiated and sensitive recording was developed and tested to pick up symptoms escaping the commonly used scores. 6) Study the relation between histopathological findings and the clinical picture. 4 papers presenting various studies are included. The titles are: 1) Acute radiation proctitis: a sequential clinicopathologic study during pelvic radiotherapy. 2) Clinical significance of increased gelatinolytic activity in the rectal mucosa during external beam radiation therapy of prostate cancer. 3) Profiles and time course of acute radiation toxicity symptoms during conformal radiotherapy for cancer of the prostate. 4) Sucralfate does not ameliorate acute radiation proctitis. Some future prospects are discussed

  3. Acute radiation proctitis. A clinical, histopathological and histochemical study

    Energy Technology Data Exchange (ETDEWEB)

    Hovdenak, Nils

    2004-07-01

    The aim of the study is: 1) A sequential description of the clinical course of acute radiation proctitis during pelvic RT. 2) A sequential description of the rectal mucosal histopathology during pelvic RT as a possible substrate for clinical toxicity. 3) To assess the mucosal protease activity during RT as a possible explanation of the observed tissue changes. 4) To assess the efficacy of prophylactic sucralfate in acute radiation proctitis a randomised study was initiated and carried out together with a meta-analysis of previously available data. 5) Most studies on clinical acute toxicity in pelvic RT use either the RTOG/EORTC score system or focus on diarrhoea/stool frequency. A more differentiated and sensitive recording was developed and tested to pick up symptoms escaping the commonly used scores. 6) Study the relation between histopathological findings and the clinical picture. 4 papers presenting various studies are included. The titles are: 1) Acute radiation proctitis: a sequential clinicopathologic study during pelvic radiotherapy. 2) Clinical significance of increased gelatinolytic activity in the rectal mucosa during external beam radiation therapy of prostate cancer. 3) Profiles and time course of acute radiation toxicity symptoms during conformal radiotherapy for cancer of the prostate. 4) Sucralfate does not ameliorate acute radiation proctitis. Some future prospects are discussed.

  4. Silica-Immobilized Enzyme Reactors; Application to Cholinesterase-Inhibition Studies

    National Research Council Canada - National Science Library

    Luckarift, Heather R; Johnson, Glenn R; Spain, Jim C

    2006-01-01

    ...) using silica-encapsulated equine butyrycholinestearse (BuChE) as a model system. Peptide-mediated silica formation was used to encapsulate BuChE, directly immobilizing the enzyme within a commercial pre-packed column...

  5. The renneting of milk : a kinetic study of the enzymic and aggregation reactions

    NARCIS (Netherlands)

    Hooydonk, van A.C.M.

    1987-01-01

    The rennet-induced clotting of milk was studied under various conditions. The kinetics of the enzymic and aggregation reactions was analysed separately and, where possible, related to the physico-chemical properties of the casein micelle and its environment.

    The effects of important

  6. Screening of SDS-degrading bacteria from car wash wastewater and study of the alkylsulfatase enzyme activity.

    Science.gov (United States)

    Shahbazi, Razieh; Kasra-Kermanshahi, Roha; Gharavi, Sara; Moosavi-Nejad, Zahra; Borzooee, Faezeh

    2013-06-01

    Sodium dodecyl sulfate (SDS) is one of the main surfactant components in detergents and cosmetics, used in high amounts as a detergent in products such as shampoos, car wash soap and toothpaste. Therefore, its bioremediation by suitable microorganisms is important. Alkylsulfatase is an enzyme that hydrolyses sulfate -ester bonds to give inorganic sulfate and alcohol. The purpose of this study was to isolate SDS-degrading bacteria from Tehran city car wash wastewater, study bacterial alkylsulfatase enzyme activity and identify the alkylsulfatase enzyme coding gene. Screening of SDS-degrading bacteria was carried out on basal salt medium containing SDS as the sole source of carbon. Amount of SDS degraded was assayed by methylene blue active substance (MBAS). Identification of the sdsA gene was carried by PCR and subsequent sequencing of the 16S rDNA gene and biochemical tests identified Pseudomonas aeruginosa. This bacterium is able to degrade 84% of SDS after four days incubation. Bacteria isolated from car wash wastewater were shown to carry the sdsA gene (670bp) and the alkylsulfatase enzyme specific activity expressed from this gene was determined to be 24.3 unit/mg. The results presented in this research indicate that Pseudomonas aeruginosa is a suitable candidate for SDS biodegradation.

  7. Immobilized enzymes: understanding enzyme - surface interactions at the molecular level.

    Science.gov (United States)

    Hoarau, Marie; Badieyan, Somayesadat; Marsh, E Neil G

    2017-11-22

    Enzymes immobilized on solid supports have important and industrial and medical applications. However, their uses are limited by the significant reductions in activity and stability that often accompany the immobilization process. Here we review recent advances in our understanding of the molecular level interactions between proteins and supporting surfaces that contribute to changes in stability and activity. This understanding has been facilitated by the application of various surface-sensitive spectroscopic techniques that allow the structure and orientation of enzymes at the solid/liquid interface to be probed, often with monolayer sensitivity. An appreciation of the molecular interactions between enzyme and surface support has allowed the surface chemistry and method of enzyme attachement to be fine-tuned such that activity and stability can be greatly enhanced. These advances suggest that a much wider variety of enzymes may eventually be amenable to immobilization as green catalysts.

  8. Glucose-6-phosphate dehydrogenase in rat lung alveolar epithelial cells. An ultrastructural enzyme-cytochemical study

    Directory of Open Access Journals (Sweden)

    S Matsubara

    2010-01-01

    Full Text Available Glucose-6-phosphate dehydrogenase (G6PD is the key enzyme of the pentose phosphate pathway in carbohydrate metabolism, and it plays an important role in cell proliferation and antioxidant regulation within cells in various organs. Although marked cell proliferation and oxidant/antioxidant metabolism occur in lung alveolar epithelial cells, definite data has been lacking as to whether cytochemically detectable G6PD is present in alveolar epithelial cells. The distribution pattern of G6PD within these cells, if it is present, is also unknown. The purpose of the present study was to investigate the subcellular localization of G6PD in alveolar cells in the rat lung using a newly- developed enzyme-cytochemistry (copper-ferrocyanide method. Type I cells and stromal endothelia and fibroblasts showed no activities. Electron-dense precipitates indicating G6PD activity were clearly visible in the cytoplasm and on the cytosolic side of the endoplasmic reticulum of type II alveolar epithelial cells. The cytochemical controls ensured specific detection of enzyme activity. This enzyme may play a role in airway defense by delivering substances for cell proliferation and antioxidant forces, thus maintaining the airway architecture.

  9. Immobilized enzyme reactor chromatography: Optimization of protein retention and enzyme activity in monolithic silica stationary phases

    International Nuclear Information System (INIS)

    Besanger, Travis R.; Hodgson, Richard J.; Green, James R.A.; Brennan, John D.

    2006-01-01

    Our group recently reported on the application of protein-doped monolithic silica columns for immobilized enzyme reactor chromatography, which allowed screening of enzyme inhibitors present in mixtures using mass spectrometry for detection. The enzyme was immobilized by entrapment within a bimodal meso/macroporous silica material prepared by a biocompatible sol-gel processing route. While such columns proved to be useful for applications such as screening of protein-ligand interactions, significant amounts of entrapped proteins leached from the columns owing to the high proportion of macropores within the materials. Herein, we describe a detailed study of factors affecting the morphology of protein-doped bioaffinity columns and demonstrate that specific pH values and concentrations of poly(ethylene glycol) can be used to prepare essentially mesoporous columns that retain over 80% of initially loaded enzyme in an active and accessible form and yet still retain sufficient porosity to allow pressure-driven flow in the low μL/min range. Using the enzyme γ-glutamyl transpeptidase (γ-GT), we further evaluated the catalytic constants of the enzyme entrapped in capillary columns with different silica morphologies as a function of flowrate and backpressure using the enzyme reactor assay mode. It was found that the apparent activity of the enzyme was highest in mesoporous columns that retained high levels of enzyme. In such columns, enzyme activity increased by ∼2-fold with increases in both flowrate (from 250 to 1000 nL/min) and backpressure generated (from 500 to 2100 psi) during the chromatographic activity assay owing to increases in k cat and decreases in K M , switching from diffusion controlled to reaction controlled conditions at ca. 2000 psi. These results suggest that columns with minimal macropore volumes (<5%) are advantageous for the entrapment of soluble proteins for bioaffinity and bioreactor chromatography

  10. Histochemical analysis of glycoconjugates in the skin of a catfish (arius tenuispinis, day).

    Science.gov (United States)

    Al-Banaw, A; Kenngott, R; Al-Hassan, J M; Mehana, N; Sinowatz, F

    2010-02-01

    A histochemical study using conventional carbohydrate histochemistry (periodic-acid staining including diastase controls, alcian blue staining at pH 1 and 2.5) as well as using a battery of 14 fluorescein isothiocyanate (FITC)-labelled lectins to identify glycoconjugates present in 10 different areas of the skin of a catfish (Arius tenuispinis) was carried out. The lectins used were: mannose-binding lectins (Con A, LCA and PSA), galactose-binding lectins (PNA, RCA), N-acetylgalactosamine-binding lectins (DBA, SBA, SJA and GSL I), N-acetylglucosamine-binding lectins (WGA and WGAs), fucose-binding lectins (UEA) and lectins which bind to complex carbohydrate configurations (PHA E, PHA L). Conventional glycoconjugate staining (PAS staining, alcian blue at pH 1 and 2.5) showed that the mucous goblet cells contain a considerable amount of glycoconjugates in all locations of the skin, whereas the other unicellular gland type, the club cells, lacked these glycoconjugates. The glycoproteins found in goblet cells are neutral and therefore stain magenta when subjected to PAS staining. Alcian blue staining indicating acid glycoproteins was distinctly positive at pH 1, but gave only a comparable staining at pH 2.5. The mucus of the goblet cells therefore also contains acid glycoproteins rich in sulphate groups. Using FITC-labelled lectins, the carbohydrate composition of the glycoproteins of goblet cells could be more fully characterized. A distinct staining of the mucus of goblet cells was found with the mannose-binding lectins LCA and PSA; the galactosamine-binding lectins DBA, SBA and GLS I; the glucosamine-binding lectin WGA; and PHA E which stains glycoproteins with complex carbohydrate configurations. No reaction occurred with the fucose-binding lectin UEA and the sialic acid-specific lectin SNA. In addition, the galactose-binding lectins PNA and RCA showed only a weak or completely negative staining of the mucus in the goblet cells. The specificity of the lectin staining

  11. Structural Studies of Bacterial Enzymes and their Relation to Antibiotic Resistance Mechanisms - Final Paper

    Energy Technology Data Exchange (ETDEWEB)

    Maltz, Lauren [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-27

    By using protein crystallography and X-ray diffraction, structures of bacterial enzymes were solved to gain a better understanding of how enzymatic modification acts as an antibacterial resistance mechanism. Aminoglycoside phosphotransferases (APHs) are one of three aminoglycoside modifying enzymes that confer resistance to the aminoglycoside antibiotics via enzymatic modification, rendering many drugs obsolete. Specifically, the APH(2”) family vary in their substrate specificities and also in their preference for the phosphate donor (ADP versus GDP). By solving the structures of members of the APH(2”) family of enzymes, we can see how domain movements are important to their substrate specificity. Our structure of the ternary complex of APH(2”)-IIIa with GDP and kanamycin, when compared to the known structures of APH(2”)-IVa, reveals that there are real physical differences between these two enzymes, a structural finding that explains why the two enzymes differ in their preferences for certain aminoglycosides. Another important group of bacterial resistance enzymes are the Class D β- lactamases. Oxacillinase carbapenemases (OXAs) are part of this enzyme class and have begun to confer resistance to ‘last resort’ drugs, most notably carbapenems. Our structure of OXA-143 shows that the conformational flexibility of a conserved hydrophobic residue in the active site (Val130) serves to control the entry of a transient water molecule responsible for a key step in the enzyme’s mechanism. Our results provide insight into the structural mechanisms of these two different enzymes

  12. Expanding the Halohydrin Dehalogenase Enzyme Family: Identification of Novel Enzymes by Database Mining.

    Science.gov (United States)

    Schallmey, Marcus; Koopmeiners, Julia; Wells, Elizabeth; Wardenga, Rainer; Schallmey, Anett

    2014-12-01

    Halohydrin dehalogenases are very rare enzymes that are naturally involved in the mineralization of halogenated xenobiotics. Due to their catalytic potential and promiscuity, many biocatalytic reactions have been described that have led to several interesting and industrially important applications. Nevertheless, only a few of these enzymes have been made available through recombinant techniques; hence, it is of general interest to expand the repertoire of these enzymes so as to enable novel biocatalytic applications. After the identification of specific sequence motifs, 37 novel enzyme sequences were readily identified in public sequence databases. All enzymes that could be heterologously expressed also catalyzed typical halohydrin dehalogenase reactions. Phylogenetic inference for enzymes of the halohydrin dehalogenase enzyme family confirmed that all enzymes form a distinct monophyletic clade within the short-chain dehydrogenase/reductase superfamily. In addition, the majority of novel enzymes are substantially different from previously known phylogenetic subtypes. Consequently, four additional phylogenetic subtypes were defined, greatly expanding the halohydrin dehalogenase enzyme family. We show that the enormous wealth of environmental and genome sequences present in public databases can be tapped for in silico identification of very rare but biotechnologically important biocatalysts. Our findings help to readily identify halohydrin dehalogenases in ever-growing sequence databases and, as a consequence, make even more members of this interesting enzyme family available to the scientific and industrial community. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  13. Relationship between sol-gel conditions and enzyme stability: a case study with β-galactosidase/silica biocatalyst for whey hydrolysis.

    Science.gov (United States)

    Escobar, Sindy; Bernal, Claudia; Mesa, Monica

    2015-01-01

    The sol-gel process has been very useful for preparing active and stable biocatalysts, with the possibility of being reused. Especially those based on silica are well known. However, the study of the enzyme behavior during this process is not well understood until now and more, if the surfactant is involved in the synthesis mixture. This work is devoted to the encapsulation of β-galactosidase from Bacillus circulans in silica by sol-gel process, assisted by non-ionic Triton X-100 surfactant. The correlation between enzyme activity results for the β-galactosidase in three different environments (soluble in buffered aqueous reference solution, in the silica sol, and entrapment on the silica matrix) explains the enzyme behavior under stress conditions offered by the silica sol composition and gelation conditions. A stable β-galactosidase/silica biocatalyst is obtained using sodium silicate, which is a cheap source of silica, in the presence of non-ionic Triton X-100, which avoids the enzyme deactivation, even at 40 °C. The obtained biocatalyst is used in the whey hydrolysis for obtaining high value products from this waste. The preservation of the enzyme stability, which is one of the most important challenges on the enzyme immobilization through the silica sol-gel, is achieved in this study.

  14. Experiment K-6-21. Effect of microgravity on 1) metabolic enzymes of type 1 and type 2 muscle fibers and on 2) metabolic enzymes, neutransmitter amino acids, and neurotransmitter associated enzymes in motor and somatosensory cerebral cortex. Part 1: Metabolic enzymes of individual muscle fibers; part 2: metabolic enzymes of hippocampus and spinal cord

    Science.gov (United States)

    Lowry, O.; Mcdougal, D., Jr.; Nemeth, Patti M.; Maggie, M.-Y. Chi; Pusateri, M.; Carter, J.; Manchester, J.; Norris, Beverly; Krasnov, I.

    1990-01-01

    The individual fibers of any individual muscle vary greatly in enzyme composition, a fact which is obscured when enzyme levels of a whole muscle are measured. The purpose of this study was therefore to assess the changes due to weightless on the enzyme patterns composed by the individual fibers within the flight muscles. In spite of the limitation in numbers of muscles examined, it is apparent that: (1) that the size of individual fibers (i.e., their dry weight) was reduced about a third, (2) that this loss in dry mass was accompanied by changes in the eight enzymes studied, and (3) that these changes were different for the two muscles, and different for the two enzyme groups. In the soleus muscle the absolute amounts of the three enzymes of oxidative metabolism decreased about in proportion to the dry weight loss, so that their concentration in the atrophic fibers was almost unchanged. In contrast, there was little loss among the four enzymes of glycogenolysis - glycolysis so that their concentrations were substantially increased in the atrophic fibers. In the TA muscle, these seven enzymes were affected in just the opposite direction. There appeared to be no absolute loss among the oxidative enzymes, whereas the glycogenolytic enzymes were reduced by nearly half, so that the concentrations of the first metabolic group were increased within the atrophic fibers and the concentrations of the second group were only marginally decreased. The behavior of hexokinase was exceptional in that it did not decrease in absolute terms in either type of muscle and probably increased as much as 50 percent in soleus. Thus, their was a large increase in concentration of this enzyme in the atrophied fibers of both muscles. Another clear-cut finding was the large increase in the range of activities of the glycolytic enzymes among individual fibers of TA muscles. This was due to the emergence of TA fibers with activities for enzymes of this group extending down to levels as low as

  15. Substâncias ergásticas foliares de espécies amazônicas de Oenocarpus Mart. (Arecaceae: caracterização histoquímica e ultra-estrutural Leaf ergastic substances of Amazonian species of Oenocarpus Mart. (Arecaceae: histochemical and ultrastructural characterization

    Directory of Open Access Journals (Sweden)

    Rolf Junior Ferreira Silva

    2009-01-01

    Full Text Available O presente estudo teve por objetivo diagnosticar e caracterizar as substâncias ergásticas foliares de Oenocarpus bacaba Mart., O. distichus Mart., O. mapora H. Karst. e O. minor Mart. através de microscopias óptica e eletrônica de varredura, análises histoquímicas e microanálises físicas. Secções transversais e longitudinais, assim como maceração foram realizadas em material botânico fixado. As análises histoquímicas foram empregadas em material botânico in natura, seguindo-se protocolos específicos para mucilagem, amido e sílica. Microanálises físicas foram feitas com Energy Dispersive Spectroscopy (EDS detector. Nas espécies estudadas de Oenocarpus Mart., as substâncias ergásticas foliares correspondem a mucilagem amorfa; grãos de amido poliédricos do tipo simples e sílica opalina sob a forma de corpos elípticos e esféricos-globosos de superfície espiculada, ambos com elevado teor de dióxido de silício. As observações microscópicas, os testes histoquímicos e as microanálises físicas permitiram diagnosticar, caracterizar e elucidar a estrutura e ultra-estrutura das substâncias ergásticas ocorrentes nas folhas dos táxons analisados de Oenocarpus Mart.The purpose of this study was to diagnose and characterize the leaf ergastic substance of Oenocarpus bacaba Mart., O. distichus Mart., O. mapora H. Karst. and O. minor Mart. by light and scanning electron microscopy, histochemical analyses and physical microanalyses. Transverse and longitudinal sections as well as maceration were made in fixed botanical material. The histochemical analyses were made in non-fixed botanical material, using specific tests for mucilage, starch and silica. An Energy Dispersive Spectroscopy (EDS detector was used for the physical microanalyses. In the Oenocarpus Mart. species studied, the leaf ergastic substances corresponded to amorphous mucilage, simple-type polyhedrical starch grain and opaline silica in the shape of elliptical

  16. Implementation of different histochemical methods in diagnostics of brain Aspergillosis in turkey chicks

    Directory of Open Access Journals (Sweden)

    Kureljušić Branislav

    2011-01-01

    histochemical methods, in addition to isolation.

  17. Subcellular localization of pituitary enzymes

    Science.gov (United States)

    Smith, R. E.

    1970-01-01

    A cytochemical procedure is reported for identifying subcellular sites of enzymes hydrolyzing beta-naphthylamine substrates, and to study the sites of reaction product localization in cells of various tissues. Investigations using the substrate Leu 4-methoxy-8-naphthylamine, a capture with hexonium pararosaniline, and the final chelation of osmium have identified the hydrolyzing enzyme of rat liver cells; this enzyme localized on cell membranes with intense deposition in the areas of the parcanaliculi. The study of cells in the anterior pituitary of the rat showed the deposition of reaction product on cell membrane; and on the membranes of secretion granules contained within the cell. The deposition of reaction product on the cell membrane however showed no increase or decrease with changes in the physiological state of the gland and release of secretion granules from specific cells.

  18. PIXE analysis of Zn enzymes

    International Nuclear Information System (INIS)

    Solis, C.; Oliver, A.; Andrade, E.; Ruvalcaba-Sil, J.L.; Romero, I.; Celis, H.

    1999-01-01

    Zinc is a necessary component in the action and structural stability of many enzymes. Some of them are well characterized, but in others, Zn stoichiometry and its association is not known. PIXE has been proven to be a suitable technique for analyzing metallic proteins embedded in electrophoresis gels. In this study, PIXE has been used to investigate the Zn content of enzymes that are known to carry Zn atoms. These include the carbonic anhydrase, an enzyme well characterized by other methods and the cytoplasmic pyrophosphatase of Rhodospirillum rubrum that is known to require Zn to be stable but not how many metal ions are involved or how they are bound to the enzyme. Native proteins have been purified by polyacrylamide gel electrophoresis and direct identification and quantification of Zn in the gel bands was performed with an external proton beam of 3.7 MeV energy

  19. Enzymes and Enzyme Activity Encoded by Nonenveloped Viruses.

    Science.gov (United States)

    Azad, Kimi; Banerjee, Manidipa; Johnson, John E

    2017-09-29

    Viruses are obligate intracellular parasites that rely on host cell machineries for their replication and survival. Although viruses tend to make optimal use of the host cell protein repertoire, they need to encode essential enzymatic or effector functions that may not be available or accessible in the host cellular milieu. The enzymes encoded by nonenveloped viruses-a group of viruses that lack any lipid coating or envelope-play vital roles in all the stages of the viral life cycle. This review summarizes the structural, biochemical, and mechanistic information available for several classes of enzymes and autocatalytic activity encoded by nonenveloped viruses. Advances in research and development of antiviral inhibitors targeting specific viral enzymes are also highlighted.

  20. Dibromine radical anion reactions with heme enzymes

    International Nuclear Information System (INIS)

    Gebicka, L.; Gebicki, J.L.

    1996-01-01

    Reactions of Br 2 radical anion with heme enzymes, catalase horseradish peroxidase, have been studied by pulse radiolysis. It has been found that Br 2 - does not react with the heme centre of investigated enzymes. Dibromine radical anion reacts with tryptophan residues of catalase without any influence on the activity of catalase. It is suggested that in pulse radiolysis studies, where horseradish peroxidase is at about tenfold excess toward Br 2 - , the enzyme is modified rather by Br 2 , than by Br 2 - . (author). 26 refs., 3 figs

  1. Advances in enzyme bioelectrochemistry

    Directory of Open Access Journals (Sweden)

    ANDRESSA R. PEREIRA

    Full Text Available ABSTRACT Bioelectrochemistry can be defined as a branch of Chemical Science concerned with electron-proton transfer and transport involving biomolecules, as well as electrode reactions of redox enzymes. The bioelectrochemical reactions and system have direct impact in biotechnological development, in medical devices designing, in the behavior of DNA-protein complexes, in green-energy and bioenergy concepts, and make it possible an understanding of metabolism of all living organisms (e.g. humans where biomolecules are integral to health and proper functioning. In the last years, many researchers have dedicated itself to study different redox enzymes by using electrochemistry, aiming to understand their mechanisms and to develop promising bioanodes and biocathodes for biofuel cells as well as to develop biosensors and implantable bioelectronics devices. Inside this scope, this review try to introduce and contemplate some relevant topics for enzyme bioelectrochemistry, such as the immobilization of the enzymes at electrode surfaces, the electron transfer, the bioelectrocatalysis, and new techniques conjugated with electrochemistry vising understand the kinetics and thermodynamics of redox proteins. Furthermore, examples of recent approaches in designing biosensors and biofuel developed are presented.

  2. Monovalent Cation Activation of the Radical SAM Enzyme Pyruvate Formate-Lyase Activating Enzyme.

    Science.gov (United States)

    Shisler, Krista A; Hutcheson, Rachel U; Horitani, Masaki; Duschene, Kaitlin S; Crain, Adam V; Byer, Amanda S; Shepard, Eric M; Rasmussen, Ashley; Yang, Jian; Broderick, William E; Vey, Jessica L; Drennan, Catherine L; Hoffman, Brian M; Broderick, Joan B

    2017-08-30

    Pyruvate formate-lyase activating enzyme (PFL-AE) is a radical S-adenosyl-l-methionine (SAM) enzyme that installs a catalytically essential glycyl radical on pyruvate formate-lyase. We show that PFL-AE binds a catalytically essential monovalent cation at its active site, yet another parallel with B 12 enzymes, and we characterize this cation site by a combination of structural, biochemical, and spectroscopic approaches. Refinement of the PFL-AE crystal structure reveals Na + as the most likely ion present in the solved structures, and pulsed electron nuclear double resonance (ENDOR) demonstrates that the same cation site is occupied by 23 Na in the solution state of the as-isolated enzyme. A SAM carboxylate-oxygen is an M + ligand, and EPR and circular dichroism spectroscopies reveal that both the site occupancy and the identity of the cation perturb the electronic properties of the SAM-chelated iron-sulfur cluster. ENDOR studies of the PFL-AE/[ 13 C-methyl]-SAM complex show that the target sulfonium positioning varies with the cation, while the observation of an isotropic hyperfine coupling to the cation by ENDOR measurements establishes its intimate, SAM-mediated interaction with the cluster. This monovalent cation site controls enzyme activity: (i) PFL-AE in the absence of any simple monovalent cations has little-no activity; and (ii) among monocations, going down Group 1 of the periodic table from Li + to Cs + , PFL-AE activity sharply maximizes at K + , with NH 4 + closely matching the efficacy of K + . PFL-AE is thus a type I M + -activated enzyme whose M + controls reactivity by interactions with the cosubstrate, SAM, which is bound to the catalytic iron-sulfur cluster.

  3. Liver Enzymes and Risk of Ischemic Heart Disease and Type 2 Diabetes Mellitus: A Mendelian Randomization Study

    OpenAIRE

    Liu, Junxi; Au Yeung, Shiu Lun; Lin, Shi Lin; Leung, Gabriel M.; Schooling, C. Mary

    2016-01-01

    We used Mendelian randomization to estimate the causal effects of the liver enzymes, alanine aminotransferase (ALT), alkaline phosphatase (ALP) and gamma glutamyltransferase (GGT), on diabetes and cardiovascular disease, using genetic variants predicting these liver enzymes at genome wide significance applied to extensively genotyped case-control studies of diabetes (DIAGRAM) and coronary artery disease (CAD)/myocardial infarction (MI) (CARDIoGRAMplusC4D 1000 Genomes). Genetically higher ALT ...

  4. Ceramic membrane microfilter as an immobilized enzyme reactor.

    Science.gov (United States)

    Harrington, T J; Gainer, J L; Kirwan, D J

    1992-10-01

    This study investigated the use of a ceramic microfilter as an immobilized enzyme reactor. In this type of reactor, the substrate solution permeates the ceramic membrane and reacts with an enzyme that has been immobilized within its porous interior. The objective of this study was to examine the effect of permeation rate on the observed kinetic parameters for the immobilized enzyme in order to assess possible mass transfer influences or shear effects. Kinetic parameters were found to be independent of flow rate for immobilized penicillinase and lactate dehydrogenase. Therefore, neither mass transfer nor shear effects were observed for enzymes immobilized within the ceramic membrane. Both the residence time and the conversion in the microfilter reactor could be controlled simply by regulating the transmembrane pressure drop. This study suggests that a ceramic microfilter reactor can be a desirable alternative to a packed bed of porous particles, especially when an immobilized enzyme has high activity and a low Michaelis constant.

  5. Angiotensin Converting Enzyme Gene Insertion/Deletion Polymorphism in Migraine Patients

    Directory of Open Access Journals (Sweden)

    Belgin Alaşehirli

    2009-12-01

    Full Text Available OBJECTIVE: The beneficial effects of angiotensin converting enzyme inhibitor drugs on migraine attack frequency have been shown. We aimed to study the relationship between the angiotensin converting enzyme gene and migraine pathophysiology. METHODS: In the present study, to assess whether the angiotensin converting enzyme insertion/deletion (I/D gene polymorphisms have an effect on migraine attacks, we studied the angiotensin converting enzyme genotypes of 102 migraine patients (35 cases of migraine with aura and 67 of migraine without aura and 75 age-and sex-matched normal volunteers. Frequency and age of onset of migraine attacks were also assessed according to angiotensin converting enzyme genotypes. RESULTS: Patients with migraine with and without aura were comparable with each other and the control group with respect to angiotensin converting enzyme genotypes (respectively; p= 0.88 and p= 0.76, p= 0.624. We could not determine a relationship between angiotensin converting enzyme genotypes and attack frequency (p= 0.125, but cases with angiotensin converting enzyme-II genotype showed a significantly younger age for onset of migraine attacks in comparison with the I/D genotype patients (p= 0.021. CONCLUSION: We believe that further angiotensin converting enzyme gene studies are warranted in younger age groups of patients with migraine and also in different populations

  6. Structural prediction and comparative docking studies of psychrophilic β- Galactosidase with lactose, ONPG and PNPG against its counter parts of mesophilic and thermophilic enzymes.

    Science.gov (United States)

    Kumar, Ponnada Suresh; Pulicherla, Kk; Ghosh, Mrinmoy; Kumar, Anmol; Rao, Krs Sambasiva

    2011-01-01

    Enzymes from psychrophiles catalyze the reactions at low temperatures with higher specific activity. Among all the psychrophilic enzymes produced, cold active β-galactosidase from marine psychrophiles revalorizes a new arena in numerous areas at industrial level. The hydrolysis of lactose in to glucose and galactose by cold active β-galactosidase offers a new promising approach in removal of lactose from milk to overcome the problem of lactose intolerance. Herein we propose, a 3D structure of cold active β-galactosidase enzyme sourced from Pseudoalteromonas haloplanktis by using Modeler 9v8 and best model was developed having 88% of favourable region in ramachandran plot. Modelling was followed by docking studies with the help of Auto dock 4.0 against the three substrates lactose, ONPG and PNPG. In addition, comparative docking studies were also performed for the 3D model of psychrophilic β-galactosidase with mesophilic and thermophilic enzymes. Docking studies revealed that binding affinity of enzyme towards the three different substrates is more for psychrophilic enzyme when compared with mesophilic and thermophilic enzymes. It indicates that the enzyme has high specific activity at low temperature when compared with mesophilic and thermophilic enzymes.

  7. Network analysis of metabolic enzyme evolution in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Kraulis Per

    2004-02-01

    Full Text Available Abstract Background The two most common models for the evolution of metabolism are the patchwork evolution model, where enzymes are thought to diverge from broad to narrow substrate specificity, and the retrograde evolution model, according to which enzymes evolve in response to substrate depletion. Analysis of the distribution of homologous enzyme pairs in the metabolic network can shed light on the respective importance of the two models. We here investigate the evolution of the metabolism in E. coli viewed as a single network using EcoCyc. Results Sequence comparison between all enzyme pairs was performed and the minimal path length (MPL between all enzyme pairs was determined. We find a strong over-representation of homologous enzymes at MPL 1. We show that the functionally similar and functionally undetermined enzyme pairs are responsible for most of the over-representation of homologous enzyme pairs at MPL 1. Conclusions The retrograde evolution model predicts that homologous enzymes pairs are at short metabolic distances from each other. In general agreement with previous studies we find that homologous enzymes occur close to each other in the network more often than expected by chance, which lends some support to the retrograde evolution model. However, we show that the homologous enzyme pairs which may have evolved through retrograde evolution, namely the pairs that are functionally dissimilar, show a weaker over-representation at MPL 1 than the functionally similar enzyme pairs. Our study indicates that, while the retrograde evolution model may have played a small part, the patchwork evolution model is the predominant process of metabolic enzyme evolution.

  8. The surface science of enzymes

    DEFF Research Database (Denmark)

    Rod, Thomas Holm; Nørskov, Jens Kehlet

    2002-01-01

    One of the largest challenges to science in the coming years is to find the relation between enzyme structure and function. Can we predict which reactions an enzyme catalyzes from knowledge of its structure-or from its amino acid sequence? Can we use that knowledge to modify enzyme function......? To solve these problems we must understand in some detail how enzymes interact with reactants from its surroundings. These interactions take place at the surface of the enzyme and the question of enzyme function can be viewed as the surface science of enzymes. In this article we discuss how to describe...... catalysis by enzymes, and in particular the analogies between enzyme catalyzed reactions and surface catalyzed reactions. We do this by discussing two concrete examples of reactions catalyzed both in nature (by enzymes) and in industrial reactors (by inorganic materials), and show that although analogies...

  9. Student Collaboration in a Series of Integrated Experiments to Study Enzyme Reactor Modeling with Immobilized Cell-Based Invertase

    Science.gov (United States)

    Taipa, M. A^ngela; Azevedo, Ana M.; Grilo, Anto´nio L.; Couto, Pedro T.; Ferreira, Filipe A. G.; Fortuna, Ana R. M.; Pinto, Ine^s F.; Santos, Rafael M.; Santos, Susana B.

    2015-01-01

    An integrative laboratory study addressing fundamentals of enzyme catalysis and their application to reactors operation and modeling is presented. Invertase, a ß-fructofuranosidase that catalyses the hydrolysis of sucrose, is used as the model enzyme at optimal conditions (pH 4.5 and 45 °C). The experimental work involves 3 h of laboratory time…

  10. Dynamic relationships between microbial biomass, respiration, inorganic nutrients and enzyme activities: informing enzyme based decomposition models

    Directory of Open Access Journals (Sweden)

    Daryl L Moorhead

    2013-08-01

    Full Text Available We re-examined data from a recent litter decay study to determine if additional insights could be gained to inform decomposition modeling. Rinkes et al. (2013 conducted 14-day laboratory incubations of sugar maple (Acer saccharum or white oak (Quercus alba leaves, mixed with sand (0.4% organic C content or loam (4.1% organic C. They measured microbial biomass C, carbon dioxide efflux, soil ammonium, nitrate, and phosphate concentrations, and β-glucosidase (BG, β-N-acetyl-glucosaminidase (NAG, and acid phosphatase (AP activities on days 1, 3, and 14. Analyses of relationships among variables yielded different insights than original analyses of individual variables. For example, although respiration rates per g soil were higher for loam than sand, rates per g soil C were actually higher for sand than loam, and rates per g microbial C showed little difference between treatments. Microbial biomass C peaked on day 3 when biomass-specific activities of enzymes were lowest, suggesting uptake of litter C without extracellular hydrolysis. This result refuted a common model assumption that all enzyme production is constitutive and thus proportional to biomass, and/or indicated that part of litter decay is independent of enzyme activity. The length and angle of vectors defined by ratios of enzyme activities (BG/NAG versus BG/AP represent relative microbial investments in C (length, and N and P (angle acquiring enzymes. Shorter lengths on day 3 suggested low C limitation, whereas greater lengths on day 14 suggested an increase in C limitation with decay. The soils and litter in this study generally had stronger P limitation (angles > 45˚. Reductions in vector angles to < 45˚ for sand by day 14 suggested a shift to N limitation. These relational variables inform enzyme-based models, and are usually much less ambiguous when obtained from a single study in which measurements were made on the same samples than when extrapolated from separate studies.

  11. A comparative molecular dynamics study of thermophilic and mesophilic β-fructosidase enzymes.

    Science.gov (United States)

    Mazola, Yuliet; Guirola, Osmany; Palomares, Sucel; Chinea, Glay; Menéndez, Carmen; Hernández, Lázaro; Musacchio, Alexis

    2015-09-01

    Arabidopsis thaliana cell wall invertase 1 (AtcwINV1) and Thermotoga maritima β-fructosidase (BfrA) are among the best structurally studied members of the glycoside hydrolase family 32. Both enzymes hydrolyze sucrose as the main substrate but differ strongly in their thermal stability. Mesophilic AtcwINV1 and thermophilic BfrA have divergent sequence similarities in the N-terminal five bladed β-propeller catalytic domain (31 %) and the C-terminal β-sandwich domain (15 %) of unknown function. The two enzymes were subjected to 200 ns molecular dynamics simulations at 300 K (27 °C) and 353 K (80 °C). Regular secondary structure regions, but not loops, in AtcwINV1 and BfrA showed no significant fluctuation differences at both temperatures. BfrA was more rigid than AtcwINV1 at 300 K. The simulation at 353 K did not alter the structural stability of BfrA, but did increase the overall flexibility of AtcwINV1 exhibiting the most fluctuating regions in the β-propeller domain. The simulated heat treatment also increased the gyration radius and hydrophobic solvent accessible surface area of the plant enzyme, consistent with the initial steps of an unfolding process. The preservation of the conformational rigidity of BfrA at 353 K is linked to the shorter size of the protein loops. Shortening of BfrA loops appears to be a key mechanism for thermostability.

  12. Co-immobilization of multiple enzymes by metal coordinated nucleotide hydrogel nanofibers: improved stability and an enzyme cascade for glucose detection.

    Science.gov (United States)

    Liang, Hao; Jiang, Shuhui; Yuan, Qipeng; Li, Guofeng; Wang, Feng; Zhang, Zijie; Liu, Juewen

    2016-03-21

    Preserving enzyme activity and promoting synergistic activity via co-localization of multiple enzymes are key topics in bionanotechnology, materials science, and analytical chemistry. This study reports a facile method for co-immobilizing multiple enzymes in metal coordinated hydrogel nanofibers. Specifically, four types of protein enzymes, including glucose oxidase, Candida rugosa lipase, α-amylase, and horseradish peroxidase, were respectively encapsulated in a gel nanofiber made of Zn(2+) and adenosine monophosphate (AMP) with a simple mixing step. Most enzymes achieved quantitative loading and retained full activity. At the same time, the entrapped enzymes were more stable against temperature variation (by 7.5 °C), protease attack, extreme pH (by 2-fold), and organic solvents. After storing for 15 days, the entrapped enzyme still retained 70% activity while the free enzyme nearly completely lost its activity. Compared to nanoparticles formed with AMP and lanthanide ions, the nanofiber gels allowed much higher enzyme activity. Finally, a highly sensitive and selective biosensor for glucose was prepared using the gel nanofiber to co-immobilize glucose oxidase and horseradish peroxidase for an enzyme cascade system. A detection limit of 0.3 μM glucose with excellent selectivity was achieved. This work indicates that metal coordinated materials using nucleotides are highly useful for interfacing with biomolecules.

  13. Magnetically responsive enzyme powders

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-04-15

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

  14. The ultrasound technology for modifying enzyme activity

    Directory of Open Access Journals (Sweden)

    Meliza Lindsay

    2016-06-01

    Full Text Available Enzymes are protein complexes compounds widely studied and used due to their ability to catalyze reactions. The food processing mainly aims the inactivation of enzymes due to various undesirable effects. However, there are many processes that can be optimized by its catalytic activity. In this context, different technologies have been applied both to inactivate or to improve the enzymes efficiency. The Ultrasound technology emerges as an alternative mainly applied to achieve the enzyme inactivation. On the contrary, very few investigations show the ability of this technology under certain conditions to achieve the opposite effect (i.e. increase the catalytic activity of enzymes. The objective of this study was to correlate the ultrasonic energy delivered to the sample (J/mL with the residual enzymatic activity and explain the possible mechanisms which results in the enzymatic activation/inactivation complex behavior. The activity of POD in coconut water was evaluated as a model. The enzymatic activity initially increased, followed by reduction with a trend to enzyme inactivation. This complex behavior is directly related to the applied ultrasonic energy and their direct mechanical effects on the product, as well as the effect in the enzymatic infinite intermediate states and its structural conformation changes. The obtained results are useful for both academic and industrial perspectives.

  15. Dimeric assembly of enterocyte brush border enzymes

    DEFF Research Database (Denmark)

    Danielsen, E M

    1994-01-01

    The noncovalent, dimeric assembly of small intestinal brush border enzymes was studied by sedimentation analysis in density gradients of extracts of pulse-labeled pig jejunal mucosal explants. Like aminopeptidase N (EC 3.4.11.2), sucrase-isomaltase (EC 3.2.1.48-10), aminopeptidase A (EC 3...... appearance of the liposome-reconstituted enzyme [Norén et al. (1986) J. Biol. Chem. 261, 12306-12309], showing only the inner, membrane-anchored domains of the monomers to be in close contact with one another while the outer domains are far apart. In contrast to the other brush border enzymes studied...

  16. Identification of an early damage of the retina by laser radiation

    International Nuclear Information System (INIS)

    Walther, G.; Hochgesand, P.; Stockhausen, M.; Valeske, W.

    1973-01-01

    The purpose of this investigation has been to find out the retinal threshold energy for a Q-switched Ruby-Laser with an impulse duration of 50 ns. A commercial Laser-Type (Fa. Eltrughs, Heidelberg, West Germany, Type CE 602) was used. For the test rabbits were used general anesthesia: the threshold energy was first determined ophthalmoscopically-enzyme-histochemically. In the first series the coagulation energy accounted between 7 x 10 -4 J and 9 x 10 -7 J, in the second between 10 -6 J and 1.5 x 10 -5 J. Clinically the threshold energy was found at a level of 3 - 5 x 10 -6 J, clinical-enzyme-histochemically at 1 - 2 x 10 -6 J. A theoretical and physical calculation leaded to 0.3 - 3 x 10 -6 J. Since the energy measurement varies and due to the different resorption qualities of the human and the rabbit's retina the threshold energy accounts 10 -7 J. Labour safety protection should prescribe a threshold energy less than 10 -8 J for a Q-switched Ruby-Laser of an impulse duration of 50 ns. (orig.) [de

  17. Thermodynamic activity-based intrinsic enzyme kinetic sheds light on enzyme-solvent interactions.

    Science.gov (United States)

    Grosch, Jan-Hendrik; Wagner, David; Nistelkas, Vasilios; Spieß, Antje C

    2017-01-01

    The reaction medium has major impact on biocatalytic reaction systems and on their economic significance. To allow for tailored medium engineering, thermodynamic phenomena, intrinsic enzyme kinetics, and enzyme-solvent interactions have to be discriminated. To this end, enzyme reaction kinetic modeling was coupled with thermodynamic calculations based on investigations of the alcohol dehydrogenase from Lactobacillus brevis (LbADH) in monophasic water/methyl tert-butyl ether (MTBE) mixtures as a model solvent. Substrate concentrations and substrate thermodynamic activities were varied separately to identify the individual thermodynamic and kinetic effects on the enzyme activity. Microkinetic parameters based on concentration and thermodynamic activity were derived to successfully identify a positive effect of MTBE on the availability of the substrate to the enzyme, but a negative effect on the enzyme performance. In conclusion, thermodynamic activity-based kinetic modeling might be a suitable tool to initially curtail the type of enzyme-solvent interactions and thus, a powerful first step to potentially understand the phenomena that occur in nonconventional media in more detail. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:96-103, 2017. © 2016 American Institute of Chemical Engineers.

  18. Enzyme-inducing anticonvulsants increase plasma clearance of dexmedetomidine: a pharmacokinetic and pharmacodynamic study.

    Science.gov (United States)

    Flexman, Alana M; Wong, Harvey; Riggs, K Wayne; Shih, Tina; Garcia, Paul A; Vacas, Susana; Talke, Pekka O

    2014-05-01

    Dexmedetomidine is useful during mapping of epileptic foci as it facilitates electrocorticography unlike most other anesthetic agents. Patients with seizure disorders taking enzyme-inducing anticonvulsants appear to be resistant to its sedative effects. The objective of the study was to compare the pharmacokinetic and pharmacodynamic profile of dexmedetomidine in healthy volunteers with volunteers with seizure disorders receiving enzyme-inducing anticonvulsant medications. Dexmedetomidine was administered using a step-wise, computer-controlled infusion to healthy volunteers (n = 8) and volunteers with seizure disorders (n = 8) taking phenytoin or carbamazapine. Sedation and dexmedetomidine plasma levels were assessed at baseline, during the infusion steps, and after discontinuation of the infusion. Sedation was assessed by using the Observer's Assessment of Alertness/Sedation Scale, Ramsay Sedation Scale, and Visual Analog Scale and processed electroencephalography (entropy) monitoring. Pharmacokinetic analysis was performed on both groups, and differences between groups were determined using the standard two-stage approach. A two-compartment model was fit to dexmedetomidine concentration-time data. Dexmedetomidine plasma clearance was 43% higher in the seizure group compared with the control group (42.7 vs. 29.9 l/h; P = 0.007). In contrast, distributional clearance and the volume of distribution of the central and peripheral compartments were similar between the groups. No difference in sedation was detected between the two groups during a controlled range of target plasma concentrations. This study demonstrates that subjects with seizure disorders taking enzyme-inducing anticonvulsant medications have an increased plasma clearance of dexmedetomidine as compared with healthy control subjects.

  19. Substrate-driven chemotactic assembly in an enzyme cascade

    Science.gov (United States)

    Zhao, Xi; Palacci, Henri; Yadav, Vinita; Spiering, Michelle M.; Gilson, Michael K.; Butler, Peter J.; Hess, Henry; Benkovic, Stephen J.; Sen, Ayusman

    2018-03-01

    Enzymatic catalysis is essential to cell survival. In many instances, enzymes that participate in reaction cascades have been shown to assemble into metabolons in response to the presence of the substrate for the first enzyme. However, what triggers metabolon formation has remained an open question. Through a combination of theory and experiments, we show that enzymes in a cascade can assemble via chemotaxis. We apply microfluidic and fluorescent spectroscopy techniques to study the coordinated movement of the first four enzymes of the glycolysis cascade: hexokinase, phosphoglucose isomerase, phosphofructokinase and aldolase. We show that each enzyme independently follows its own specific substrate gradient, which in turn is produced by the preceding enzymatic reaction. Furthermore, we find that the chemotactic assembly of enzymes occurs even under cytosolic crowding conditions.

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

    Science.gov (United States)

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

    2010-01-25

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

  1. Evaluation of thermostable enzymes for bioethanol processing

    DEFF Research Database (Denmark)

    Skovgaard, Pernille Anastasia

    of fermentable sugars (glucose) as cellulose is tightly linked to hemicellulose and lignin. Lignocellulose is disrupted during pretreatment, but to degrade cellulose to single sugars, lignocellulolytic enzymes such as cellulases and hemicellulases are needed. Lignocellulolytic enzymes are costly...... for the ioethanol production, but the expenses can be reduced by using thermostable enzymes, which are known for their increased stability and inhibitor olerance. However, the advantage of using thermostable enzymes has not been studied thoroughly and more knowledge is needed for development of bioethanol processes....... Enzymes are added to the bioethanol process after pretreatment. For an efficient sugar and ethanol yield, the solids content of biomass is normally increased, which results in highly viscous slurries that are difficult to mix. Therefore, the first enzymatic challenge is to ensure rapid reduction...

  2. Linking Hydrolysis Performance to Trichoderma reesei Cellulolytic Enzyme Profile

    DEFF Research Database (Denmark)

    Lehmann, Linda Olkjær; Petersen, Nanna; I. Jørgensen, Christian

    2016-01-01

    Trichoderma reesei expresses a large number of enzymes involved in lignocellulose hydrolysis and the mechanism of how these enzymes work together is too complex to study by traditional methods, e.g. by spiking with single enzymes and monitoring hydrolysis performance. In this study a multivariate...... approach, partial least squares regression, was used to see if it could help explain the correlation between enzyme profile and hydrolysis performance. Diverse enzyme mixtures were produced by Trichoderma reesei Rut-C30 by exploiting various fermentation conditions and used for hydrolysis of washed...

  3. Effect of irradiation on immobilized enzymes compared with that on enzymes in solution

    International Nuclear Information System (INIS)

    Schachinger, L.; Schippel, C.; Altmann, E.; Diepold, B.; Yang, C.; Jaenike, M.; Hochhaeuser, E.

    1985-01-01

    Glucose oxidase and catalase were immobilized by attaching them to nylon fibers that had been treated with triethyloxonium-tetrafluoroborate, diaminohexane and glutaraldialdehyde according to Morris, Campell and Hornby (1975). This method assures that the enzymes are bound to a side chain of the polyamide structure. Enzyme activity (as measured by the O 2 -uptake and by microcalorimetry) was found to be unchanged after 2 years. The apparent Ksub(m)-constants of the immobilized enzymes with glucose were the same as those for enzymes in solution. GOD and catalase immobilized in poly(acrylamide) gel had the same Ksub(m)-value. Despite the high stability during storage, the radiation induced inactivation of enzymes immobilized on gel or chromosorb, an inorganic carrier, was of the same order of magnitude as that of the dissolved enzymes. The enzymes bound to nylon fibers showed a higher radiation sensitivity. This might have been caused by an additional attack on the binding site of the carrier. (orig.)

  4. Multi-enzyme catalyzed processes: Next generation biocatalysis

    DEFF Research Database (Denmark)

    Andrade Santacoloma, Paloma de Gracia; Sin, Gürkan; Gernaey, Krist

    2011-01-01

    Biocatalysis has been attracting increasing interest in recent years. Nevertheless, most studies concerning biocatalysis have been carried out using single enzymes (soluble or immobilized). Currently, multiple enzyme mixtures are attractive for the production of many compounds at an industrial...

  5. Direct Electron Transfer of Enzymes in a Biologically Assembled Conductive Nanomesh Enzyme Platform.

    Science.gov (United States)

    Lee, Seung-Woo; Lee, Ki-Young; Song, Yong-Won; Choi, Won Kook; Chang, Joonyeon; Yi, Hyunjung

    2016-02-24

    Nondestructive assembly of a nanostructured enzyme platform is developed in combination of the specific biomolecular attraction and electrostatic coupling for highly efficient direct electron transfer (DET) of enzymes with unprecedented applicability and versatility. The biologically assembled conductive nanomesh enzyme platform enables DET-based flexible integrated biosensors and DET of eight different enzyme with various catalytic activities. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Escherichia coli photoreactivating enzyme: purification and properties

    International Nuclear Information System (INIS)

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

    1980-01-01

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

  7. Strategies for enzyme saving during saccharification of pretreated lignocellulo-starch biomass: effect of enzyme dosage and detoxification chemicals

    Directory of Open Access Journals (Sweden)

    M.G. Mithra

    2017-08-01

    Full Text Available Two strategies leading to enzyme saving during saccharification of pretreated lignocellulo-starch biomass (LCSB was investigated which included reducing enzyme dosage by varying their levels in enzyme cocktails and enhancing the fermentable sugar yield in enzyme-reduced systems using detoxification chemicals. Time course release of reducing sugars (RS during 24–120 h was significantly higher when an enzyme cocktail containing full dose of cellulase (16 FPU/g cellulose along with half dose each of xylanase (1.5 mg protein/g hemicelluloses and Stargen (12.5 μl/g biomass was used to saccharify conventional dilute sulphuric acid (DSA pretreated biomass compared to a parallel system where only one-fourth the dose of the latter two enzymes was used. The reduction in RS content in the 120 h saccharified mash to the extent of 3–4 g/L compared to the system saccharified with full complement of the three enzymes could be overcome considerably by supplementing the system (half dose of two enzymes with detoxification chemical mix incorporating Tween 20, PEG 4000 and sodium borohydride. Microwave (MW-assisted DSA pretreated biomass on saccharification with enzyme cocktail having full dose of cellulase and half dose of Stargen along with detoxification chemicals gave significantly higher RS yield than DSA pretreated system saccharified using three enzymes. The study showed that xylanase could be eliminated during saccharification of MW-assisted DSA pretreated biomass without affecting RS yield when detoxification chemicals were also supplemented. The Saccharification Efficiency and Overall Conversion Efficiency were also high for the MW-assisted DSA pretreated biomass. Since whole slurry saccharifcation of pretreated biomass is essential to conserve fermentable sugars in LCSB saccharification, detoxification of soluble inhibitors is equally important as channelling out of insoluble lignin remaining in the residue. As one of the major factors contributing

  8. Biochemical approaches to C4 photosynthesis evolution studies: the case of malic enzymes decarboxylases.

    Science.gov (United States)

    Saigo, Mariana; Tronconi, Marcos A; Gerrard Wheeler, Mariel C; Alvarez, Clarisa E; Drincovich, María F; Andreo, Carlos S

    2013-11-01

    C4 photosynthesis enables the capture of atmospheric CO2 and its concentration at the site of RuBisCO, thus counteracting the negative effects of low atmospheric levels of CO2 and high atmospheric levels of O2 (21 %) on photosynthesis. The evolution of this complex syndrome was a multistep process. It did not occur by simply recruiting pre-exiting components of the pathway from C3 ancestors which were already optimized for C4 function. Rather it involved modifications in the kinetics and regulatory properties of pre-existing isoforms of non-photosynthetic enzymes in C3 plants. Thus, biochemical studies aimed at elucidating the functional adaptations of these enzymes are central to the development of an integrative view of the C4 mechanism. In the present review, the most important biochemical approaches that we currently use to understand the evolution of the C4 isoforms of malic enzyme are summarized. It is expected that this information will help in the rational design of the best decarboxylation processes to provide CO2 for RuBisCO in engineering C3 species to perform C4 photosynthesis.

  9. Histochemical studies on genetical control of hormonal enzyme inducibility in the mouse. I. Non-specific esterase activity and regional histology of the epididymis

    DEFF Research Database (Denmark)

    Blecher, S R; Kirkeby, S

    1978-01-01

    As a base line for future cell genetical studies the authors record the distribution of non-specific esterase reaction in the various histologically distinguishable cell types of the mouse epididymis. The findings are correlated with previous descriptions of the lobar structure of the organ...

  10. Enzymes for improved biomass conversion

    Science.gov (United States)

    Brunecky, Roman; Himmel, Michael E.

    2016-02-02

    Disclosed herein are enzymes and combinations of the enzymes useful for the hydrolysis of cellulose and the conversion of biomass. Methods of degrading cellulose and biomass using enzymes and cocktails of enzymes are also disclosed.

  11. Self-powered enzyme micropumps

    Science.gov (United States)

    Sengupta, Samudra; Patra, Debabrata; Ortiz-Rivera, Isamar; Agrawal, Arjun; Shklyaev, Sergey; Dey, Krishna K.; Córdova-Figueroa, Ubaldo; Mallouk, Thomas E.; Sen, Ayusman

    2014-05-01

    Non-mechanical nano- and microscale pumps that function without the aid of an external power source and provide precise control over the flow rate in response to specific signals are needed for the development of new autonomous nano- and microscale systems. Here we show that surface-immobilized enzymes that are independent of adenosine triphosphate function as self-powered micropumps in the presence of their respective substrates. In the four cases studied (catalase, lipase, urease and glucose oxidase), the flow is driven by a gradient in fluid density generated by the enzymatic reaction. The pumping velocity increases with increasing substrate concentration and reaction rate. These rechargeable pumps can be triggered by the presence of specific analytes, which enables the design of enzyme-based devices that act both as sensor and pump. Finally, we show proof-of-concept enzyme-powered devices that autonomously deliver small molecules and proteins in response to specific chemical stimuli, including the release of insulin in response to glucose.

  12. Toxicological Studies of Mycotoxins Using Enzymatic and Histochemical Methods

    Energy Technology Data Exchange (ETDEWEB)

    Badea, Mihaela, E-mail: badeamihaela@yahoo.com; Taus, Nicoleta [Transilvania University of Brasov, Faculty of Medicine (Romania); Potrovita, Monica [Sanitary-Veterinary and Food Safety Direction of Brasov (Romania); Moarcas, Monica [Transilvania University of Brasov, Faculty of Medicine (Romania)

    2009-08-15

    Studies concerning mycotoxins involve activities of relevant potential for furthering knowledge in the fields of toxicology and environmental analysis. Using bioanalytical methods (biosensors, histochemistry), the conducted research aims at contributing to raising the awareness of local, national, and international media in relation to the safety of obtaining and processing vegetal and animal foods, by analyzing the possible effects of aflatoxins and ochratoxins, promoting animal health, food hygiene, in view of ensuring animal and human health. The study using laboratory animals (mice) while being part of one of the current national research directions, also holds international priority, by its contribution to a better understanding of several fundamental mechanisms of life at molecular level and to the characterization of certain biological processes that appear in mycotoxicosis.

  13. An appraisal of the enzyme stability-activity trade-off.

    Science.gov (United States)

    Miller, Scott R

    2017-07-01

    A longstanding idea in evolutionary physiology is that an enzyme cannot jointly optimize performance at both high and low temperatures due to a trade-off between stability and activity. Although a stability-activity trade-off has been observed for well-characterized examples, such a trade-off is not imposed by any physical chemical constraint. To better understand the pervasiveness of this trade-off, I investigated the stability-activity relationship for comparative biochemical studies of purified orthologous enzymes identified by a literature search. The nature of this relationship varied greatly among studies. Notably, studies of enzymes with low mean synonymous nucleotide sequence divergence were less likely to exhibit the predicted negative correlation between stability and activity. Similarly, a survey of directed evolution investigations of the stability-activity relationship indicated that these traits are often uncoupled among nearly identical yet phenotypically divergent enzymes. This suggests that the presumptive trade-off often reported for investigations of enzymes with high mean sequence divergence may in some cases instead be a consequence of the degeneration over time of enzyme function in unselected environments, rather than a direct effect of thermal adaptation. The results caution against the general assertion of a stability-activity trade-off during enzyme adaptation. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

  14. Activity assessment of microbial fibrinolytic enzymes.

    Science.gov (United States)

    Kotb, Essam

    2013-08-01

    Conversion of fibrinogen to fibrin inside blood vessels results in thrombosis, leading to myocardial infarction and other cardiovascular diseases. In general, there are four therapy options: surgical operation, intake of antiplatelets, anticoagulants, or fibrinolytic enzymes. Microbial fibrinolytic enzymes have attracted much more attention than typical thrombolytic agents because of the expensive prices and the side effects of the latter. The fibrinolytic enzymes were successively discovered from different microorganisms, the most important among which is the genus Bacillus. Microbial fibrinolytic enzymes, especially those from food-grade microorganisms, have the potential to be developed as functional food additives and drugs to prevent or cure thrombosis and other related diseases. There are several assay methods for these enzymes; this may due to the insolubility of substrate, fibrin. Existing assay methods can be divided into three major groups. The first group consists of assay of fibrinolytic activity with natural proteins as substrates, e.g., fibrin plate methods. The second and third groups of assays are suitable for kinetic studies and are based on the determination of hydrolysis of synthetic peptide esters. This review will deal primarily with the microorganisms that have been reported in literature to produce fibrinolytic enzymes and the first review discussing the methods used to assay the fibrinolytic activity.

  15. Enhanced Oil Recovery with Application of Enzymes

    DEFF Research Database (Denmark)

    Khusainova, Alsu

    Enzymes have recently been reported as effective enhanced oil recovery (EOR) agents. Both laboratory and field tests demonstrated significant increase in the ultimate oil production. Up to16% of additional oil was produced in the laboratory conditions and up to 269 barrels of additional oil per day...... were recovered in the field applications. The following mechanisms were claimed to be responsible for the enhancement of the oil production due to enzymes: wettability improvement of the rock surface; formation of the emulsions; reduction of oil viscosity; and removal of high molecular weight paraffins....... However, the positive effect of enzymes on oil recovery is not that obvious. In most of the studies commercial enzyme products composed of enzymes, surfactants and stabilisers were used. Application of such samples makes it difficult to assign a positive EOR effect to a certain compound, as several...

  16. Binding affinity and adhesion force of organophosphate hydrolase enzyme with soil particles related to the isoelectric point of the enzyme.

    Science.gov (United States)

    Islam, Shah Md Asraful; Yeasmin, Shabina; Islam, Md Saiful; Islam, Md Shariful

    2017-07-01

    The binding affinity of organophosphate hydrolase enzyme (OphB) with soil particles in relation to the isoelectric point (pI) was studied. Immobilization of OphB with soil particles was observed by confocal microscopy, Fourier transform infrared spectroscopy (FT-IR), and Atomic force microscopy (AFM). The calculated pI of OphB enzyme was increased from 8.69 to 8.89, 9.04 and 9.16 by the single, double and triple mutant of OphB enzyme, respectively through the replacement of negatively charged aspartate with positively charged histidine. Practically, the binding affinity was increased to 5.30%, 11.50%, and 16.80% for single, double and triple mutants, respectively. In contrast, enzyme activity of OphB did not change by the mutation of the enzyme. On the other hand, adhesion forces were gradually increased for wild type OphB enzyme (90 pN) to 96, 100 and 104 pN for single, double and triple mutants of OphB enzyme, respectively. There was an increasing trend of binding affinity and adhesion force by the increase of isoelectric point (pI) of OphB enzyme. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Optimization of ultrasound-assisted extraction of pectinase enzyme from guava (Psidium guajava) peel: Enzyme recovery, specific activity, temperature, and storage stability.

    Science.gov (United States)

    Amid, Mehrnoush; Murshid, Fara Syazana; Manap, Mohd Yazid; Islam Sarker, Zaidul

    2016-01-01

    This study aimed to investigate the effects of the ultrasound-assisted extraction conditions on the yield, specific activity, temperature, and storage stability of the pectinase enzyme from guava peel. The ultrasound variables studied were sonication time (10-30 min), ultrasound temperature (30-50 °C), pH (2.0-8.0), and solvent-to-sample ratio (2:1 mL/g to 6:1 mL/g). The main goal was to optimize the ultrasound-assisted extraction conditions to maximize the recovery of pectinase from guava peel with the most desirable enzyme-specific activity and stability. Under the optimum conditions, a high yield (96.2%), good specific activity (18.2 U/mg), temperature stability (88.3%), and storage stability (90.3%) of the extracted enzyme were achieved. The optimal conditions were 20 min sonication time, 40 °C temperature, at pH 5.0, using a 4:1 mL/g solvent-to-sample ratio. The study demonstrated that optimization of ultrasound-assisted process conditions for the enzyme extraction could improve the enzymatic characteristics and yield of the enzyme.

  18. A High-Throughput (HTS) Assay for Enzyme Reaction Phenotyping in Human Recombinant P450 Enzymes Using LC-MS/MS.

    Science.gov (United States)

    Li, Xiaofeng; Suhar, Tom; Glass, Lateca; Rajaraman, Ganesh

    2014-03-03

    Enzyme reaction phenotyping is employed extensively during the early stages of drug discovery to identify the enzymes responsible for the metabolism of new chemical entities (NCEs). Early identification of metabolic pathways facilitates prediction of potential drug-drug interactions associated with enzyme polymorphism, induction, or inhibition, and aids in the design of clinical trials. Incubation of NCEs with human recombinant enzymes is a popular method for such work because of the specificity, simplicity, and high-throughput nature of this approach for phenotyping studies. The availability of a relative abundance factor and calculated intersystem extrapolation factor for the expressed recombinant enzymes facilitates easy scaling of in vitro data, enabling in vitro-in vivo extrapolation. Described in this unit is a high-throughput screen for identifying enzymes involved in the metabolism of NCEs. Emphasis is placed on the analysis of the human recombinant enzymes CYP1A2, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2B6, and CYP3A4, including the calculation of the intrinsic clearance for each. Copyright © 2014 John Wiley & Sons, Inc. All rights reserved.

  19. The ultrasound technology for modifying enzyme activity

    Directory of Open Access Journals (Sweden)

    Meliza Lindsay Rojas

    2016-01-01

    Full Text Available Enzymes are protein complexes compounds widely studied and used due to their ability to catalyze reactions. The food processing mainly a ims the inactivation of enzymes due to various undesirable effects. However, there are many processes that can be optimized by its catalytic activity. In this context, different technologies have been applied both to inactivate or to improve the enzymes ef ficiency. The Ultrasound technology emerges as an alternative mainly applied to achieve the enzyme inactivation. On the contrary, very few investigations show the ability of this technology under certain conditions to achieve the opposite effect (i.e. increase the catalytic activity of enzymes. The objective of this study was to correlate the ultrasonic energy delivered to the sample (J/mL with the residual enzymatic activity and explain the possible mechanisms which results in the enzymatic activation/in activation complex behavior. The activity of POD in coconut water was evaluated as a model. The enzymatic activity initially increased, followed by reduction with a trend to enzyme inactivation. This complex behavior is directly related to the applied ultr asonic energy and their direct mechanical effects on the product, as well as the effect in the enzymatic infinite intermediate states and its structural conformation changes. The obtained results are useful for both academic and industrial perspectives.

  20. Análise histoquímica foliar do amendoim: genótipos 'Tatu' e SO-909 Leaf histochemical analyses of peanut: genotypes 'Tatu' and SO-909

    Directory of Open Access Journals (Sweden)

    Renato Ferraz de Arruda Veiga

    1992-01-01

    Full Text Available Este trabalho teve por finalidade a análise histoquímica foliar de dois genótipos de amendoim (Arachis hypogaea L., do tipo botânico Valência: SO-53 ('Tatu' e SO-909 (PI-259747, cuja literatura demonstra apresentarem respostas diferentes de resistência às principais moléstias fúngicas foliares do Brasil. Seções transversais das seguintes estruturas - pulvino, haste peciolar, raque, pulvínulo e folíolo - e seções paradérmicas de folíolos coletados em dois anos agrícolas consecutivos, foram analisadas quanto à presença de alcalóides, amido, calose, celulose pura, celulose com pectina, cera, cristais, cutina, lignina, mucilagem, óleo, resina, tanino e ureídeos (micrograma por folíolo (grama. As diferenças qualitativas histoquímicas observadas nos diversos tecidos, como a freqüência de tanino, alcalóide, pectina e óleo, supostamente, podem ser responsáveis pela resistência ou suscetibilidade dos genótipos às moléstias fúngicas foliares. Para fins de caracterização, mostrou-se eficiente a avaliação de pureza de celulose.Leaf histochemical analyses were made in two genotypes of Arachis hypogaea L., of the Valencia group, which present different responses to some of the peanut foliar diseases. The analyses were performed on cross sections of the pulvini, petiole, rachis, pulvinulus and leaflets. The following constituents were observed: alkaloids, callose, cellulose with pectin, cristal, cutin, lignin, mucilage, oil, pure cellulose, resin, starch, tannin, wax and weight of ureides by leaflets. Some histochemical characteristics such the amount of tannin, alkaloids, pectin and oil can be produce different responses of peanut to foliar fungal diseases, and can be used in the characterization of peanut genotypes like the amount of pure cellulose and cellulose with pectin.

  1. Laccase Enzymes in Inocula Pleurotus spp

    Directory of Open Access Journals (Sweden)

    Nora García-Oduardo

    2017-01-01

    Full Text Available The cultivation of edible and medicinal mushrooms Pleurotus has been aimed at promoting alternative management for agricultural products. This basidiomicete has been the subject of numerous studies because of its fruiting body constitutes a food, being a producer of enzymes with industrial interest and for its ability of biotransformation of lignocellulosic substrates. Pleurotus inocula in the established technology for growing edible and medicinal mushrooms in the CEBI Research- Production Plant were performed using sorghum or wheat. However, it is possible to expand the possibilities with other substrates. In this paper, the results of laccase enzymes production in inocula prepared with sorghum, corn and coffee pulp with two strains Pleurotus ostreatus CCEBI 3021 and Pleurotus ostreatus CCEBI 3024 are presented. The period of preparation of seed reaches 15-21 days, the measurements of laccase activity were performed in periods of seven days. Extraction of crude enzyme was performed in aqueous phase, the determination of the laccase enzyme activity, using guaiacol as substrate. The results obtained in this work with studies in previous work using sorghum as inocula are compared. It is found that higher yields are obtained laccase in coffee pulp. This study contributes to the theoretical knowledge and to provide alternatives for securing the production process of the plant.

  2. Enzyme inhibition by iminosugars

    DEFF Research Database (Denmark)

    López, Óscar; Qing, Feng-Ling; Pedersen, Christian Marcus

    2013-01-01

    Imino- and azasugar glycosidase inhibitors display pH dependant inhibition reflecting that both the inhibitor and the enzyme active site have groups that change protonation state with pH. With the enzyme having two acidic groups and the inhibitor one basic group, enzyme-inhibitor complexes...

  3. Targeted enzyme prodrug therapies.

    Science.gov (United States)

    Schellmann, N; Deckert, P M; Bachran, D; Fuchs, H; Bachran, C

    2010-09-01

    The cure of cancer is still a formidable challenge in medical science. Long-known modalities including surgery, chemotherapy and radiotherapy are successful in a number of cases; however, invasive, metastasized and inaccessible tumors still pose an unresolved and ongoing problem. Targeted therapies designed to locate, detect and specifically kill tumor cells have been developed in the past three decades as an alternative to treat troublesome cancers. Most of these therapies are either based on antibody-dependent cellular cytotoxicity, targeted delivery of cytotoxic drugs or tumor site-specific activation of prodrugs. The latter is a two-step procedure. In the first step, a selected enzyme is accumulated in the tumor by guiding the enzyme or its gene to the neoplastic cells. In the second step, a harmless prodrug is applied and specifically converted by this enzyme into a cytotoxic drug only at the tumor site. A number of targeting systems, enzymes and prodrugs were investigated and improved since the concept was first envisioned in 1974. This review presents a concise overview on the history and latest developments in targeted therapies for cancer treatment. We cover the relevant technologies such as antibody-directed enzyme prodrug therapy (ADEPT), gene-directed enzyme prodrug therapy (GDEPT) as well as related therapies such as clostridial- (CDEPT) and polymer-directed enzyme prodrug therapy (PDEPT) with emphasis on prodrug-converting enzymes, prodrugs and drugs.

  4. MORFOLOGICAL AND HISTOCHEMICAL OBSERVATIONS ON THE SALIVARY GLANDS OF THE ALLIGATOR Caiman latirostris OBSERVAÇÕES MORFOLÓGICAS E HISTOQUÍMICAS SOBRE AS GLÂNDULAS SALIVARES DO JACARÉ Caiman latirostris (Crocodilia Reptilia

    Directory of Open Access Journals (Sweden)

    Gilson Herbert de Faria

    2007-09-01

    Full Text Available

    Using histological and histochemical methods for glicoconjugates, the present work on the salivary glands of the alligator Caiman latirostris (Crocodilia Reptilia, was developed. On the bases of the results obtained, the authors believe that those glands are not well developed, appearing as unicellular structures goblet-like cells, in the stratified squamous epithelium of the oral cavity. Scattered glands alveolus without excretory tubules which extend directly with the epitelium were also present. By means of histochemical methods for glicoconjugates, it was possible to detect the glicoprotein and the sialic acid in the glandular formation of these animals.

    Empregando-se métodos histológicos e histoquímicos para glicoconjugados, desenvolveu-se um trabalho sobre glândulas salivares do jacaré Caiman latirostris. Com base nos resultados obtidos, constatou-se que estas glândulas são pouco desenvolvidas, aparecendo como estruturas unicelulares, semelhantes às células caliciformes, incluídas no epitélio estratificado pavimentoso da cavidade oral. Observou-se, ainda, a presença de esparsos alvéolos glandulares desprovidos de ductos excretores que continuam diretamente com o epitélio. Por meio de métodos histoquímicos para glicoconjugados, foi possível a detecção de glicoproteína e de ácido siálico nas formações glandulares desses animais.

  5. Enzyme-Powered Pumps: From Fundamentals to Applications

    Science.gov (United States)

    Ortiz-Rivera, Isamar

    Non-mechanical nano and microfluidic devices that function without the aid of an external power source, and can be tailored to meet specific needs, represent the next generation of smart devices. Recently, we have shown that surface-bound enzymes can act as pumps driving large-scale fluid flows in the presence of any substance that triggers the enzymatic reaction (e.g. substrate, co-factor, or biomarker). The fluid velocities attained in such systems depend directly on the enzymatic reaction rate and the concentration of the substance that initiates enzymatic catalysis. The use of biochemical reactions to power a micropump offers the advantages of specificity, sensitivity, and selectively, eliminating at the same time the need of an external power source, while providing biocompatibility. More importantly, these self-powered pumps overcome a significant obstacle in nano- and micro-fluidics: the need to use external pressure-driven pumps to push fluids through devices. Certainly, the development of enzyme-powered devices opens up new venues in biochemical engineering, particularly in the biomedical field. The work highlighted in this dissertation covers all the studies performed with enzyme-powered pumps, from the development of the micropump design, to the efforts invested in understanding the enzyme pump concept as a whole. The data collected to date, aims to expand our knowledge about enzyme-powered micropumps from the inside out: not only by exploring the different applications of these devices at the macroscale, but also by investigating in depth the mechanism of pump activation behind these systems. Specifically, we have focused on: (1) The general features that characterize the pumping behavior observed in enzyme-powered pumps, as well as the optimization of the device, (2) the possible mechanisms behind fluid motion, including the role of enzyme coverage and/or activity on the transduction of chemical energy into mechanical fluid flow in these devices

  6. Insights into catalytic activity of industrial enzyme Co-nitrile hydratase. Docking studies of nitriles and amides.

    Science.gov (United States)

    Peplowski, Lukasz; Kubiak, Karina; Nowak, Wieslaw

    2007-07-01

    Nitrile hydratase (NHase) is an enzyme containing non-corrin Co3+ in the non-standard active site. NHases from Pseudonocardia thermophila JCM 3095 catalyse hydration of nitriles to corresponding amides. The efficiency of the enzyme is 100 times higher for aliphatic nitriles then aromatic ones. In order to understand better this selectivity dockings of a series of aliphatic and aromatic nitriles and related amides into a model protein based on an X-ray structure were performed. Substantial differences in binding modes were observed, showing better conformational freedom of aliphatic compounds. Distinct interactions with postranslationally modified cysteines present in the active site of the enzyme were observed. Modeling shows that water molecule activated by a metal ion may easily directly attack the docked acrylonitrile to transform this molecule into acryloamide. Thus docking studies provide support for one of the reaction mechanisms discussed in the literature.

  7. Visualization of enzyme activities inside earthworm pores

    Science.gov (United States)

    Hoang, Duyen; Razavi, Bahar S.

    2015-04-01

    In extremely dynamic microhabitats as bio-pores made by earthworm, the in situ enzyme activities are assumed as a footprint of complex biotic interactions. Our study focused on the effect of earthworm on the enzyme activities inside bio-pores and visualizing the differences between bio-pores and earthworm-free soil by zymography technique (Spohn and Kuzyakov, 2013). For the first time, we aimed at quantitative imaging of enzyme activities in bio-pores. Lumbricus terrestris L. was placed into transparent box (15×20×15cm). After two weeks when bio-pore systems were formed by earthworms, we visualized in situ enzyme activities of five hydrolytic enzymes (β-glucosidase, cellobiohydrolase, chitinase, xylanase, leucine-aminopeptidase, and phosphatase. Zymography showed higher activity of β-glucosidase, chitinase, xylanase and phosphatase in biopores comparing to bulk soil. However, the differences in activity of cellobiohydrolase and leucine aminopeptidase between bio-pore and bulk soil were less pronounced. This demonstrated an applicability of zymography approach to monitor and to distinguish the in situ activity of hydrolytic enzymes in soil biopores.

  8. Isolation and optimization of pectinase enzyme production one of useful industrial enzyme in Aspergillus niger, Rhizopus oryzae, Penicilium chrysogenum

    Directory of Open Access Journals (Sweden)

    akram songol

    2016-06-01

    Full Text Available Introduction: Pectinase enzyme is one of the most important industrial enzymes which isolated from a wide variety of microorganisms such as bacteria and filamentous fungi. This enzyme has been usually used in the fruit and textile industry. In this study, the isolation and optimization of pectinase-producing fungi on decaying rotten fruits were studied. Materials and methods: Isolation and screening of pectinase producing fungi performed through plate culture on pectin medium and staining with Lugol's iodine solution. The best strains were identified by ITS1, 4 sequencing as Aspergillus fumigatus, Rhizopus oryzae, Penicilium chrysogenum. The enzyme production was optimized by application of the five factorial design, each at three levels. These factors are carbon sources (whey, glucose and stevia, ammonium sulfate, manganese sulfate, temperature, and pH. Pectinase concentration was measured by the Miller method. Results: The results indicate that optimum condition for enzyme production for three fungi strains was obtained at 32 °C, pH = 6, 3g / L manganese sulfate, 2.75g / L of ammonium sulfate and 10g / L of each carbon source. The best experiment in obtaining the optimum enzyme contained 1.328 mg / ml of glucose for Aspergillus niger 1.284 and 1.039 mg / ml of whey for Rhizopus oryzae and Penicilium chrysogenum. Molecular weight of enzyme was about 40 and 37 kDa which was obtained by SDS- PAGE. Discussion and conclusion: The results indicate that three strains could grow in a wide range of carbon source, pH and temperature, which could be a good candidate for industrial application.

  9. DNA Damage: Quantum Mechanics/Molecular Mechanics Study on the Oxygen Binding and Substrate Hydroxylation Step in AlkB Repair Enzymes

    Science.gov (United States)

    Quesne, Matthew G; Latifi, Reza; Gonzalez-Ovalle, Luis E; Kumar, Devesh; de Visser, Sam P

    2014-01-01

    AlkB repair enzymes are important nonheme iron enzymes that catalyse the demethylation of alkylated DNA bases in humans, which is a vital reaction in the body that heals externally damaged DNA bases. Its mechanism is currently controversial and in order to resolve the catalytic mechanism of these enzymes, a quantum mechanics/molecular mechanics (QM/MM) study was performed on the demethylation of the N1-methyladenine fragment by AlkB repair enzymes. Firstly, the initial modelling identified the oxygen binding site of the enzyme. Secondly, the oxygen activation mechanism was investigated and a novel pathway was found, whereby the catalytically active iron(IV)–oxo intermediate in the catalytic cycle undergoes an initial isomerisation assisted by an Arg residue in the substrate binding pocket, which then brings the oxo group in close contact with the methyl group of the alkylated DNA base. This enables a subsequent rate-determining hydrogen-atom abstraction on competitive σ-and π-pathways on a quintet spin-state surface. These findings give evidence of different locations of the oxygen and substrate binding channels in the enzyme and the origin of the separation of the oxygen-bound intermediates in the catalytic cycle from substrate. Our studies are compared with small model complexes and the effect of protein and environment on the kinetics and mechanism is explained. PMID:24339041

  10. New insights about enzyme evolution from large scale studies of sequence and structure relationships

    OpenAIRE

    Babbitt, Patricia; Brown, SD; Babbitt, PC

    2014-01-01

    © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.Understanding how enzymes have evolved offers clues about their structure-function relationships and mechanisms. Here, we describe evolution of functionally diverse enzyme superfami

  11. A study of the fine structure, enzyme activities and pattern of 14CO2 ...

    African Journals Online (AJOL)

    A detailed study of selected grasses has been made with respect to fine structures characteristics, enzyme activities associated with C-4 and C-3 pathway photosynthesis, and short term carbon dioxide-14 incorporation experiments. A good correlation was obtained between the fine structure, the carbon pathway and the ...

  12. In-situ chemical analyses of trans-polyisoprene by histochemical staining and Fourier transform infrared microspectroscopy in a rubber-producing plant, Eucommia ulmoides Oliver.

    Science.gov (United States)

    Bamba, Takeshi; Fukusaki, Ei-Ichiro; Nakazawa, Yoshihisa; Kobayashi, Akio

    2002-10-01

    The localization of polyisoprene in young stem tissues of Eucommia ulmoides Oliver was investigated by histochemical staining and Fourier transform infrared (FT-IR) microspectroscopy. The fibrous structures were stained with Oil Red O. FT-IR microspectroscopic analysis proved that the fibrous structures were trans-polyisoprene. Granular structures stained with the dye, and characteristic absorptions at 2,960 cm(-1) and 1,430 cm(-1) in FT-IR suggested that trans-polyisoprene accumulated in the vicinity of the cambium layer. We have thus successfully shown for the first time the localization of trans-polyisoprene in plant tissues, and our histological investigation allowed us to presume the main sites of biosynthesis and accumulation of trans-rubber. Furthermore, a new technical approach, the preparation of sections using an electronic freezing unit and the in situ analysis of polyisoprene using FT-IR microspectroscopy, is demonstrated to be a promising method for determining the accumulation of polyisoprene as well as other metabolites.

  13. Enzyme recycling in lignocellulosic biorefineries

    DEFF Research Database (Denmark)

    Jørgensen, Henning; Pinelo, Manuel

    2017-01-01

    platform. Cellulases are the most important enzymes required in this process, but the complex nature of lignocellulose requires several other enzymes (hemicellulases and auxiliary enzymes) for efficient hydrolysis. Enzyme recycling increases the catalytic productivity of the enzymes by reusing them...... for several batches of hydrolysis, and thereby reduces the overall cost associated with the hydrolysis. Research on this subject has been ongoing for many years and several promising technologies and methods have been developed and demonstrated. But only in a very few cases have these technologies been...... upscaled and tested in industrial settings, mainly because of many difficulties with recycling of enzymes from the complex lignocellulose hydrolyzate at industrially relevant conditions, i.e., high solids loadings. The challenges are associated with the large number of different enzymes required...

  14. SKPDB: a structural database of shikimate pathway enzymes

    Directory of Open Access Journals (Sweden)

    de Azevedo Walter F

    2010-01-01

    Full Text Available Abstract Background The functional and structural characterisation of enzymes that belong to microbial metabolic pathways is very important for structure-based drug design. The main interest in studying shikimate pathway enzymes involves the fact that they are essential for bacteria but do not occur in humans, making them selective targets for design of drugs that do not directly impact humans. Description The ShiKimate Pathway DataBase (SKPDB is a relational database applied to the study of shikimate pathway enzymes in microorganisms and plants. The current database is updated regularly with the addition of new data; there are currently 8902 enzymes of the shikimate pathway from different sources. The database contains extensive information on each enzyme, including detailed descriptions about sequence, references, and structural and functional studies. All files (primary sequence, atomic coordinates and quality scores are available for downloading. The modeled structures can be viewed using the Jmol program. Conclusions The SKPDB provides a large number of structural models to be used in docking simulations, virtual screening initiatives and drug design. It is freely accessible at http://lsbzix.rc.unesp.br/skpdb/.

  15. Enzymes of industrial purpose - review of the market of enzyme preparations and prospects for its development

    Directory of Open Access Journals (Sweden)

    A. A. Tolkacheva

    2017-01-01

    Full Text Available Microbial enzyme preparations are increasingly replacing conventional chemical catalysts in a number of industrial processes. Such drugs, in addition to environmental friendliness and high activity, have a number of advantages over enzyme preparations of vegetable and animal origin, namely: the production of microbial enzymes in bioreactors is easily controlled and predictable; excreted microbiological enzymes are more stable than intracellular animals and plant enzymes; the genetic diversity of microorganisms makes it possible to produce enzyme preparations with a wide range of specificity; microbiological enzymes can be synthesized year-round, in contrast to the production of plant enzymes, which is often seasonal. The leaders of the world market of enzymes are proteases and amylases, which account for 25% and 15%, respectively. Over the past five years, the world market for carbohydrases, including mainly amylases, cellulases and xylanases, has been the fastest growing segment of the enzyme market with an aggregate annual growth rate of more than 7.0%. Another major product of the industrial enzyme market, which has a great potential for growth, is lipases. From the point of view of designation, the main part is represented by food and food enzymes. The Russian market continues to be unsaturated - the current supply is not able to meet the needs of the Russian feed and food industry in enzyme preparations. Enzyme preparations of domestic producers are in demand in forage production, while food industrial enterprises prefer imported products. The most significant enterprises in the enzymatic industry in Russia at the moment are Sibbiofarm, AgroSistema, Agroferment. In the light of the Russian policy of increasing food security, the development of the domestic enzyme industry is an extremely topical task.

  16. Continuous enzyme reactions with immobilized enzyme tubes prepared by radiation cast-polymerization

    International Nuclear Information System (INIS)

    Kumakura, Minoru; Kaetsu, Isao

    1986-01-01

    Immobilized glucose oxidase tubes were prepared by radiation cast-polymerization of 2-hydroxyethyl methacrylate and tetraethyleneglycol diacrylate monomer at low temperatures. The immobilized enzyme tubes which were spirally set in a water bath were used as reactor, in which the enzyme activity varied with tube size and flow rate of the substrate. The conversion yield of the substrate in continuous enzyme reaction was about 80%. (author)

  17. Enzyme Activity Experiments Using a Simple Spectrophotometer

    Science.gov (United States)

    Hurlbut, Jeffrey A.; And Others

    1977-01-01

    Experimental procedures for studying enzyme activity using a Spectronic 20 spectrophotometer are described. The experiments demonstrate the effect of pH, temperature, and inhibitors on enzyme activity and allow the determination of Km, Vmax, and Kcat. These procedures are designed for teaching large lower-level biochemistry classes. (MR)

  18. Internal Diffusion-Controlled Enzyme Reaction: The Acetylcholinesterase Kinetics.

    Science.gov (United States)

    Lee, Sangyun; Kim, Ji-Hyun; Lee, Sangyoub

    2012-02-14

    Acetylcholinesterase is an enzyme with a very high turnover rate; it quenches the neurotransmitter, acetylcholine, at the synapse. We have investigated the kinetics of the enzyme reaction by calculating the diffusion rate of the substrate molecule along an active site channel inside the enzyme from atomic-level molecular dynamics simulations. In contrast to the previous works, we have found that the internal substrate diffusion is the determinant of the acetylcholinesterase kinetics in the low substrate concentration limit. Our estimate of the overall bimolecular reaction rate constant for the enzyme is in good agreement with the experimental data. In addition, the present calculation provides a reasonable explanation for the effects of the ionic strength of solution and the mutation of surface residues of the enzyme. The study suggests that internal diffusion of the substrate could be a key factor in understanding the kinetics of enzymes of similar characteristics.

  19. Mononuclear non-heme iron enzymes with the 2-His-1-carboxylate facial triad: recent developments in enzymology and modeling studies.

    Science.gov (United States)

    Bruijnincx, Pieter C A; van Koten, Gerard; Klein Gebbink, Robertus J M

    2008-12-01

    Iron-containing enzymes are one of Nature's main means of effecting key biological transformations. The mononuclear non-heme iron oxygenases and oxidases have received the most attention recently, primarily because of the recent availability of crystal structures of many different enzymes and the stunningly diverse oxidative transformations that these enzymes catalyze. The wealth of available structural data has furthermore established the so-called 2-His-1-carboxylate facial triad as a new common structural motif for the activation of dioxygen. This superfamily of mononuclear iron(ii) enzymes catalyzes a wide range of oxidative transformations, ranging from the cis-dihydroxylation of arenes to the biosynthesis of antibiotics such as isopenicillin and fosfomycin. The remarkable scope of oxidative transformations seems to be even broader than that associated with oxidative heme enzymes. Not only are many of these oxidative transformations of key biological importance, many of these selective oxidations are also unprecedented in synthetic organic chemistry. In this critical review, we wish to provide a concise background on the chemistry of the mononuclear non-heme iron enzymes characterized by the 2-His-1-carboxylate facial triad and to discuss the many recent developments in the field. New examples of enzymes with unique reactivities belonging to the superfamily have been reported. Furthermore, key insights into the intricate mechanistic details and reactive intermediates have been obtained from both enzyme and modeling studies. Sections of this review are devoted to each of these subjects, i.e. the enzymes, biomimetic models, and reactive intermediates (225 references).

  20. Non-homologous isofunctional enzymes: a systematic analysis of alternative solutions in enzyme evolution.

    Science.gov (United States)

    Omelchenko, Marina V; Galperin, Michael Y; Wolf, Yuri I; Koonin, Eugene V

    2010-04-30

    Evolutionarily unrelated proteins that catalyze the same biochemical reactions are often referred to as analogous - as opposed to homologous - enzymes. The existence of numerous alternative, non-homologous enzyme isoforms presents an interesting evolutionary problem; it also complicates genome-based reconstruction of the metabolic pathways in a variety of organisms. In 1998, a systematic search for analogous enzymes resulted in the identification of 105 Enzyme Commission (EC) numbers that included two or more proteins without detectable sequence similarity to each other, including 34 EC nodes where proteins were known (or predicted) to have distinct structural folds, indicating independent evolutionary origins. In the past 12 years, many putative non-homologous isofunctional enzymes were identified in newly sequenced genomes. In addition, efforts in structural genomics resulted in a vastly improved structural coverage of proteomes, providing for definitive assessment of (non)homologous relationships between proteins. We report the results of a comprehensive search for non-homologous isofunctional enzymes (NISE) that yielded 185 EC nodes with two or more experimentally characterized - or predicted - structurally unrelated proteins. Of these NISE sets, only 74 were from the original 1998 list. Structural assignments of the NISE show over-representation of proteins with the TIM barrel fold and the nucleotide-binding Rossmann fold. From the functional perspective, the set of NISE is enriched in hydrolases, particularly carbohydrate hydrolases, and in enzymes involved in defense against oxidative stress. These results indicate that at least some of the non-homologous isofunctional enzymes were recruited relatively recently from enzyme families that are active against related substrates and are sufficiently flexible to accommodate changes in substrate specificity.

  1. Association of thymine glycol lesioned DNA with repair enzyme endonuclease III-molecular dynamics study

    International Nuclear Information System (INIS)

    Pinak, Miroslav

    2001-07-01

    The 2 nanoseconds molecular dynamics (MD) simulation has been performed for the system consisting of repair enzyme and DNA 30-mer with native thymine at position 16 replaced by thymine glycol (TG) solvated in water environment. After 950 picoseconds of MD the enzyme and DNA associated together to form complex that lasted stable up to 2 ns when simulation was terminated. At the contact area of enzyme and DNA there is glutamic acid located as close as 1.6 A to the C3' atom of phosphodiester bond of TG. Initial B-DNA molecule was bent and kinked at the TG during MD. This distortion caused that phosphodiester bond was easier accessible by amino acids of enzyme. The negative value of electrostatic energy (-26 kcal/mol) discriminates TG from nearly neutral native thymine and contributes to the specific recognition of this lesion. Higher number of close water molecules at TG site before formation of complex (compared with other nucleotides) indicates that glycosyl bond of the lesion is easily approached by repair enzyme during scanning of DNA surface and suggests the importance of specific hydration at the lesion during recognition process. (author)

  2. Association of thymine glycol lesioned DNA with repair enzyme endonuclease III-molecular dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Pinak, Miroslav [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-07-01

    The 2 nanoseconds molecular dynamics (MD) simulation has been performed for the system consisting of repair enzyme and DNA 30-mer with native thymine at position 16 replaced by thymine glycol (TG) solvated in water environment. After 950 picoseconds of MD the enzyme and DNA associated together to form complex that lasted stable up to 2 ns when simulation was terminated. At the contact area of enzyme and DNA there is glutamic acid located as close as 1.6 A to the C3' atom of phosphodiester bond of TG. Initial B-DNA molecule was bent and kinked at the TG during MD. This distortion caused that phosphodiester bond was easier accessible by amino acids of enzyme. The negative value of electrostatic energy (-26 kcal/mol) discriminates TG from nearly neutral native thymine and contributes to the specific recognition of this lesion. Higher number of close water molecules at TG site before formation of complex (compared with other nucleotides) indicates that glycosyl bond of the lesion is easily approached by repair enzyme during scanning of DNA surface and suggests the importance of specific hydration at the lesion during recognition process. (author)

  3. Impact of Bee Venom Enzymes on Diseases and Immune Responses.

    Science.gov (United States)

    Hossen, Md Sakib; Shapla, Ummay Mahfuza; Gan, Siew Hua; Khalil, Md Ibrahim

    2016-12-27

    Bee venom (BV) is used to treat many diseases and exhibits anti-inflammatory, anti-bacterial, antimutagenic, radioprotective, anti-nociceptive immunity promoting, hepatocyte protective and anti-cancer activity. According to the literature, BV contains several enzymes, including phospholipase A2 (PLA2), phospholipase B, hyaluronidase, acid phosphatase and α-glucosidase. Recent studies have also reported the detection of different classes of enzymes in BV, including esterases, proteases and peptidases, protease inhibitors and other important enzymes involved in carbohydrate metabolism. Nevertheless, the physiochemical properties and functions of each enzyme class and their mechanisms remain unclear. Various pharmacotherapeutic effects of some of the BV enzymes have been reported in several studies. At present, ongoing research aims to characterize each enzyme and elucidate their specific biological roles. This review gathers all the current knowledge on BV enzymes and their specific mechanisms in regulating various immune responses and physiological changes to provide a basis for future therapies for various diseases.

  4. Impact of Bee Venom Enzymes on Diseases and Immune Responses

    Directory of Open Access Journals (Sweden)

    Md. Sakib Hossen

    2016-12-01

    Full Text Available Bee venom (BV is used to treat many diseases and exhibits anti-inflammatory, anti-bacterial, antimutagenic, radioprotective, anti-nociceptive immunity promoting, hepatocyte protective and anti-cancer activity. According to the literature, BV contains several enzymes, including phospholipase A2 (PLA2, phospholipase B, hyaluronidase, acid phosphatase and α-glucosidase. Recent studies have also reported the detection of different classes of enzymes in BV, including esterases, proteases and peptidases, protease inhibitors and other important enzymes involved in carbohydrate metabolism. Nevertheless, the physiochemical properties and functions of each enzyme class and their mechanisms remain unclear. Various pharmacotherapeutic effects of some of the BV enzymes have been reported in several studies. At present, ongoing research aims to characterize each enzyme and elucidate their specific biological roles. This review gathers all the current knowledge on BV enzymes and their specific mechanisms in regulating various immune responses and physiological changes to provide a basis for future therapies for various diseases.

  5. Archaeal Enzymes and Applications in Industrial Biocatalysts.

    Science.gov (United States)

    Littlechild, Jennifer A

    2015-01-01

    Archaeal enzymes are playing an important role in industrial biotechnology. Many representatives of organisms living in "extreme" conditions, the so-called Extremophiles, belong to the archaeal kingdom of life. This paper will review studies carried by the Exeter group and others regarding archaeal enzymes that have important applications in commercial biocatalysis. Some of these biocatalysts are already being used in large scale industrial processes for the production of optically pure drug intermediates and amino acids and their analogues. Other enzymes have been characterised at laboratory scale regarding their substrate specificity and properties for potential industrial application. The increasing availability of DNA sequences from new archaeal species and metagenomes will provide a continuing resource to identify new enzymes of commercial interest using both bioinformatics and screening approaches.

  6. Effect of deletion polymorphism of angiotensin converting enzyme gene on progression of diabetic nephropathy during inhibition of angiotensin converting enzyme

    DEFF Research Database (Denmark)

    Parving, H H; Jacobsen, P; Tarnow, L

    1996-01-01

    OBJECTIVE: To evaluate the concept that an insertion/deletion polymorphism of the angiotensin converting enzyme gene predicts the therapeutic efficacy of inhibition of angiotensin converting enzyme on progression of diabetic nephropathy. DESIGN: Observational follow up study of patients with insu...

  7. Meta-analysis of genome-wide association studies on the intolerance of angiotensin-converting enzyme inhibitors

    NARCIS (Netherlands)

    Mahmoudpour, Seyed H.; Veluchamy, Abirami; Siddiqui, Moneeza K.; Asselbergs, Folkert W.; Souverein, Patrick C.; De Keyser, Catherine E.; Hofman, Albert; Lang, Chim C.; Doney, Alexander S.F.; Stricker, Bruno H.; De Boer, Anthonius; Maitland-Van Der Zee, Anke H.; Palmer, Colin N.A.

    2017-01-01

    Objectives To identify single nucleotide polymorphisms (SNPs) associated with switching from an angiotensin-converting enzyme (ACE)-inhibitor to an angiotensin receptor blocker. Methods Two cohorts of patients starting ACE-inhibitors were identified within the Rotterdam Study in the Netherlands and

  8. Preparation of immobilized enzyme membrane by radiation-cast-polymerization

    International Nuclear Information System (INIS)

    Kumakura, M.; Kaetsu, I.

    1989-01-01

    The preparation of immobilized enzyme membranes was studied by radiation cast-polymerization at low temperatures using cellulase enzyme, hydrophilic and hydrophobic monomers. The enzyme activity of the membranes was affected by monomer concentration, membrane thickness, and hydrophilicity of monomer, in which the membranes with 100 μm thickness from high monomer concentration (80%) had high enzyme activity, which was similar to that of the membranes with 1.0 mm thickness from low monomer concentration (20%). (author)

  9. Effect of neohesperidin dihydrochalcone on the activity and stability of alpha-amylase: a comparative study on bacterial, fungal, and mammalian enzymes.

    Science.gov (United States)

    Kashani-Amin, Elaheh; Ebrahim-Habibi, Azadeh; Larijani, Bagher; Moosavi-Movahedi, Ali Akbar

    2015-10-01

    Neohesperidin dihydrochalcone (NHDC) was recently introduced as an activator of mammalian alpha-amylase. In the current study, the effect of NHDC has been investigated on bacterial and fungal alpha-amylases. Enzyme assays and kinetic analysis demonstrated the capability of NHDC to significantly activate both tested alpha-amylases. The ligand activation pattern was found to be more similar between the fungal and mammalian enzyme in comparison with the bacterial one. Further, thermostability experiments indicated a stability increase in the presence of NHDC for the bacterial enzyme. In silico (docking) test locates a putative binding site for NHDC on alpha-amylase surface in domain B. This domain shows differences in various alpha-amylase types, and the different behavior of the ligand toward the studied enzymes may be attributed to this fact. Copyright © 2015 John Wiley & Sons, Ltd.

  10. Enzyme activity assay of glycoprotein enzymes based on a boronate affinity molecularly imprinted 96-well microplate.

    Science.gov (United States)

    Bi, Xiaodong; Liu, Zhen

    2014-12-16

    Enzyme activity assay is an important method in clinical diagnostics. However, conventional enzyme activity assay suffers from apparent interference from the sample matrix. Herein, we present a new format of enzyme activity assay that can effectively eliminate the effects of the sample matrix. The key is a 96-well microplate modified with molecularly imprinted polymer (MIP) prepared according to a newly proposed method called boronate affinity-based oriented surface imprinting. Alkaline phosphatase (ALP), a glycoprotein enzyme that has been routinely used as an indicator for several diseases in clinical tests, was taken as a representative target enzyme. The prepared MIP exhibited strong affinity toward the template enzyme (with a dissociation constant of 10(-10) M) as well as superb tolerance for interference. Thus, the enzyme molecules in a complicated sample matrix could be specifically captured and cleaned up for enzyme activity assay, which eliminated the interference from the sample matrix. On the other hand, because the boronate affinity MIP could well retain the enzymatic activity of glycoprotein enzymes, the enzyme captured by the MIP was directly used for activity assay. Thus, additional assay time and possible enzyme or activity loss due to an enzyme release step required by other methods were avoided. Assay of ALP in human serum was successfully demonstrated, suggesting a promising prospect of the proposed method in real-world applications.

  11. Enzymic lactose hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J J; Brand, J C

    1980-01-01

    Acid or enzymic hydrolysis can be used to hydrolyze lactose. Advantages of both are compared and details of enzymic hydrolysis using yeast or fungal enzymes given. The new scheme outlined involves recycling lactase. Because lactose and lactase react to ultrafiltration (UF) membranes differently separation is possible. Milk or milk products are ultrafiltered to separate a concentrate from a lactose-rich permeate which is treated with lactase in a reactor until hydrolysis reaches a required level. The lactase can be removed by UF as it does not permeate the membrane, and it is recycled back to the reactor. Permeate from the second UF stage may or may not be recombined with the concentrate from the first stage to produce a low lactose product (analysis of a typical low-lactose dried whole milk is given). Batch or continuous processes are explained and a batch process without enzyme recovery is discussed. (Refs. 4).

  12. Intestinal enzyme distribution after supralethal irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Becciolini, A; Gerber, G B; Buracchi, A; Deroo, J [Florence Univ. (Italy). Istituto di Radiologia; Centre d' Etude de l' Energie Nucleaire, Mol (Belgium). Dept. de Radiobiologie)

    1977-07-01

    The activity of some intestinal enzymes has been studied after 2 kR irradiation. Brush border enzymes, maltase and leucineaminopeptidase (LAP) show an increase 20 hours after irradiation, while after 72 hours their activities are reduced to very low levels. Lysosomal enzymes show a completely different behaviour: acid phosphatase activity increases only 72 hours after irradiation, whereas ..beta.. glucuronidase increases significantly after 20 hours and reaches values two or three times higher than controls after 72 hours. The histologic picture at the first interval after irradiation shows gross alterations in the crypt region, but the villi appear nearly normal. Seventy-two hours after irradiation the whole epithelium is affected and very numerous leukocytes are present in the stroma.

  13. Enzyme Mimics: Advances and Applications.

    Science.gov (United States)

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

    2016-06-13

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

  14. Bacterial and Fungal Proteolytic Enzymes: Production, Catalysis and Potential Applications.

    Science.gov (United States)

    da Silva, Ronivaldo Rodrigues

    2017-09-01

    Submerged and solid-state bioprocesses have been extensively explored worldwide and employed in a number of important studies dealing with microbial cultivation for the production of enzymes. The development of these production technologies has facilitated the generation of new enzyme-based products with applications in pharmaceuticals, food, bioactive peptides, and basic research studies, among others. The applicability of microorganisms in biotechnology is potentiated because of their various advantages, including large-scale production, short time of cultivation, and ease of handling. Currently, several studies are being conducted to search for new microbial peptidases with peculiar biochemical properties for industrial applications. Bioprospecting, being an important prerequisite for research and biotechnological development, is based on exploring the microbial diversity for enzyme production. Limited information is available on the production of specific proteolytic enzymes from bacterial and fungal species, especially on the subgroups threonine and glutamic peptidases, and the seventh catalytic type, nonhydrolytic asparagine peptide lyase. This gap in information motivated the present study about these unique biocatalysts. In this study, the biochemical and biotechnological aspects of the seven catalytic types of proteolytic enzymes, namely aspartyl, cysteine, serine, metallo, glutamic, and threonine peptidase, and asparagine peptide lyase, are summarized, with an emphasis on new studies, production, catalysis, and application of these enzymes.

  15. Random-walk enzymes

    Science.gov (United States)

    Mak, Chi H.; Pham, Phuong; Afif, Samir A.; Goodman, Myron F.

    2015-09-01

    Enzymes that rely on random walk to search for substrate targets in a heterogeneously dispersed medium can leave behind complex spatial profiles of their catalyzed conversions. The catalytic signatures of these random-walk enzymes are the result of two coupled stochastic processes: scanning and catalysis. Here we develop analytical models to understand the conversion profiles produced by these enzymes, comparing an intrusive model, in which scanning and catalysis are tightly coupled, against a loosely coupled passive model. Diagrammatic theory and path-integral solutions of these models revealed clearly distinct predictions. Comparison to experimental data from catalyzed deaminations deposited on single-stranded DNA by the enzyme activation-induced deoxycytidine deaminase (AID) demonstrates that catalysis and diffusion are strongly intertwined, where the chemical conversions give rise to new stochastic trajectories that were absent if the substrate DNA was homogeneous. The C →U deamination profiles in both analytical predictions and experiments exhibit a strong contextual dependence, where the conversion rate of each target site is strongly contingent on the identities of other surrounding targets, with the intrusive model showing an excellent fit to the data. These methods can be applied to deduce sequence-dependent catalytic signatures of other DNA modification enzymes, with potential applications to cancer, gene regulation, and epigenetics.

  16. Enzyme loading dependence of cellulose hydrolysis of sugarcane bagasse

    Directory of Open Access Journals (Sweden)

    Carlos Martín

    2012-01-01

    Full Text Available The enzymatic hydrolysis of steam-pretreated sugarcane bagasse, either delignified or non-delignified, was studied as a function of enzyme loading. Hydrolysis experiments were carried out using five enzyme loadings (2.5 to 20 FPU/g cellulose and the concentration of solids was 2% for both materials. Alkaline delignification improved cellulose hydrolysis by increasing surface area. For both materials, glucose concentrations increased with enzyme loading. On the other hand, enzyme loadings higher than 15 FPU/g did not result in any increase in the initial rate, since the excess of enzyme adsorbed onto the substrate restricted the diffusion process through the structure.

  17. Enzyme Molecules in Solitary Confinement

    Directory of Open Access Journals (Sweden)

    Raphaela B. Liebherr

    2014-09-01

    Full Text Available Large arrays of homogeneous microwells each defining a femtoliter volume are a versatile platform for monitoring the substrate turnover of many individual enzyme molecules in parallel. The high degree of parallelization enables the analysis of a statistically representative enzyme population. Enclosing individual enzyme molecules in microwells does not require any surface immobilization step and enables the kinetic investigation of enzymes free in solution. This review describes various microwell array formats and explores their applications for the detection and investigation of single enzyme molecules. The development of new fabrication techniques and sensitive detection methods drives the field of single molecule enzymology. Here, we introduce recent progress in single enzyme molecule analysis in microwell arrays and discuss the challenges and opportunities.

  18. Screening genus Penicillium for producers of cellulolytic and xylanolytic enzymes

    DEFF Research Database (Denmark)

    Krogh, Kristian Bertel Rømer; Mørkeberg, Astrid; Frisvad, Jens Christian

    2004-01-01

    For enzymatic hydrolysis of lignocellulosic material, cellulolytic enzymes from Trichoderma reesei are most commenly used, but, there is a need for more efficient enzyme cocktails. In this study, the production of cellulolytic and xylanolytic enzymes was investigated in 12 filamentous fungi from ...

  19. Enzyme technology: Key to selective biorefining

    DEFF Research Database (Denmark)

    Meyer, Anne S.

    2014-01-01

    to the reaction is a unique trait of enzyme catalysis. Since enzyme selectivity means that a specific reaction is catalysed between particular species to produce definite products, enzymes are particularly fit for converting specific compounds in mixed biomass streams. Since enzymes are protein molecules...... their rational use in biorefinery processes requires an understanding of the basic features of enzymes and reaction traits with respect to specificity, kinetics, reaction optima, stability and structure-function relations – we are now at a stage where it is possible to use nature’s enzyme structures as starting...... point and then improve the functional traits by targeted mutation of the protein. The talk will display some of our recent hypotheses related to enzyme action, recently obtained results within knowledge-based enzyme improvements as well as cast light on research methods used in optimizing enzyme...

  20. Dipeptidyl Peptidase IV in Angiotensin-Converting Enzyme Inhibitor–Associated Angioedema

    OpenAIRE

    Byrd, James Brian; Touzin, Karine; Sile, Saba; Gainer, James V.; Yu, Chang; Nadeau, John; Adam, Albert; Brown, Nancy J.

    2007-01-01

    Angioedema is a potentially life-threatening adverse effect of angiotensin-converting enzyme inhibitors. Bradykinin and substance P, substrates of angiotensin-converting enzyme, increase vascular permeability and cause tissue edema in animals. Studies indicate that amino-terminal degradation of these peptides, by aminopeptidase P and dipeptidyl peptidase IV, may be impaired in individuals with angiotensin-converting enzyme inhibitor–associated angioedema. This case-control study tested the hy...

  1. Enzyme based soil stabilization for unpaved road construction

    Directory of Open Access Journals (Sweden)

    Renjith Rintu

    2017-01-01

    Full Text Available Enzymes as soil stabilizers have been successfully used in road construction in several countries for the past 30 years. However, research has shown that the successful application of these enzymes is case specific, emphasizing that enzyme performance is dependent on subgrade soil type, condition and the type of enzyme used as the stabilizer. A universal standard or a tool for road engineers to assess the performance of stabilized unbound pavements using well-established enzymes is not available to date. The research aims to produce a validated assessment tool which can be used to predict strength enhancement within a generalized statistical framework. The objective of the present study is to identify new materials for developing the assessment tool which supports enzyme based stabilization, as well as to identify the correct construction sequence for such new materials. A series of characterization tests were conducted on several soil types obtained from proposed construction sites. Having identified the suitable soil type to mix with the enzyme, a trial road construction has been performed to investigate the efficiency of the enzyme stabilization along with the correct construction sequence. The enzyme stabilization has showed significant improvement of the road performance as was evidenced from the test results which were based on site soil obtained before and after stabilization. The research will substantially benefit the road construction industry by not only replacing traditional construction methods with economical/reliable approaches, but also eliminating site specific tests required in current practice of enzyme based road construction.

  2. Optimization of condition for conjugation of enrofloxacin to enzymes in chemiluminescence enzyme immunoassay

    Science.gov (United States)

    Yu, Songcheng; Yu, Fei; Zhang, Hongquan; Qu, Lingbo; Wu, Yongjun

    2014-06-01

    In this study, in order to find out a proper method for conjugation of enrofloxacin to label enzymes, two methods were compared and carbodiimide condensation was proved to be better. The results showed that the binding ratio of enrofloxacin and alkaline phosphatase (ALP) was 8:1 and that of enrofloxacin and horseradish peroxidase (HRP) was 5:1. This indicated that conjugate synthesized by carbodiimide condensation was fit for chemiluminescence enzyme immunoassay (CLEIA). Furthermore, data revealed that dialysis time was an important parameter for conjugation and 6 days was best. Buffer to dilute conjugate had little effect on CLEIA. The storage condition for conjugates was also studied and it was shown that the conjugate was stable at 4 °C with no additive up to 30 days. These data were valuable for establishing CLEIA to quantify enrofloxacin.

  3. Nanoarmored Enzymes for Organic Enzymology: Synthesis and Characterization of Poly(2-Alkyloxazoline)-Enzyme Conjugates.

    Science.gov (United States)

    Leurs, Melanie; Tiller, Joerg C

    2017-01-01

    The properties of enzymes can be altered significantly by modification with polymers. Numerous different methods are known to obtain such polymer-enzyme conjugates (PECs). However, there is no universal method to render enzymes into PECs that are fully soluble in organic solvents. Here, we present a method, which achieves such high degree of modification of proteins that the majority of modified enzymes will be soluble in organic solvents. This is achieved by preparing poly(2-alkyloxazoline)s (POx) with an NH 2 end group and coupling this functional polymer via pyromellitic acid dianhydride onto the amino groups of the respective protein. The resulting PECs are capable of serving as surfactants for unmodified proteins, rendering the whole mixture organosoluble. Depending on the nature of the POx and the molecular weight and the nature of the enzyme, the PECs are soluble in chloroform or even toluene. Another advantage of this method is that the poly(2-alkyloxazoline) can be activated with the coupling agent and used for the enzyme conjugation without further purification. The POx-enzyme conjugates generated by this modification strategy show modulated catalytic activity in both, aqueous and organic, systems. © 2017 Elsevier Inc. All rights reserved.

  4. Effect of exogenous cellulase enzyme on feed digestibility in lamb

    International Nuclear Information System (INIS)

    Boonek, Lerchat; Shinkoi, Henrry S; Piadang, Nattayana

    2006-09-01

    The aim of this study was to determine the effect of exogenous enzyme on digestibility and N retention in lamb. Eight lambs were randomly allocated to 2 experiment group in group comparison design trial. Experimental treatments were: 1) CTL (No enzyme) and 2 50NZ (Mixed enzyme with high cellulase at 50g/100kg.feed). The digestibility study showed that Exogenous enzyme increased (P<0.05) dry matter and crude protein digestibility of treated lamb compared to those of control. A similar trend (P=0.11) was observed for the NDF digestibility. Mean values for dry matter digestibility were 57.86 and 69.83% and for protein digestibility were 64.76 and 73.38%, for CTL and 50NZ, respectively). The N intake was similar among treatment, averaging 22.57g/head/day. Percent N retained of 50 NZ treated lambs was higher (P<.05) than those of CTL group (mean value were 47.74 and 59.07 for CTC and 50NZ, respectively). Feed efficiency or feed conversion ratio was numerically improved for enzyme-treated groups. Overall, the results of this study provide evidence that mixed cellulase enzyme can be used to improver performance of lambs as compare to non-enzyme diet.

  5. Diagnóstico precoce da leptopirose por demonstração de antígenos através de exame imuno-histoquímico em músculo da panturrilha Early diagnosis of leptospirosis by immune histochemical examination of hamstring muscles

    Directory of Open Access Journals (Sweden)

    David Everson Uip

    1992-10-01

    Full Text Available As dificuldades para estabelecer diagnóstico precoce e de certeza da leptospirose levaram-nos a analisar as alterações histopatológicas do músculo gastrocnêmio e avaliar, originalmente, a utilidade de método imuno-histoquímico, da peroxidase-antiperoxidase, quando desejada a demonstração do espiroquetídeo e de seus produtos no referido tecido. O estudo histopatológico de biópsias da panturrilha configurou quadro de miosite, caracterizado pela correlação entre o infiltrado inflamatório intersticial e as anormalidades degenerativo-necróticas das fibras musculares. As lesões foram consideradas mínimas em 69,45% dos pacientes, moderadas em 19,45% e intensas em 5,55%, estando ausentes nos demais. Por seu turno, o método imuno-histoquímico enzimático identificou antígeno leptospirótico em 94,45%, configurando resultado muito expressivo.Establishing an early and certain diagnosis of leptospirosis has been a difficult task. So, we analysed the histopathological alterations of the gastrocnemius muscle, and studied, for the first time, the usefulness of the immune histochemical method of peroxidase-antiperoxidase for the demonstration of the spirochete and of its products in this tissue. Histopathological observations have shown a picture of miositis, characterized by interstitial inflammatory infiltrate and necrotic-degenerative abnormalities of muscle fibers. The lesions were considered minimal in 69.45% of the patients, moderate in 19.45%, severe in 5.55% and absent in the remaining. On the other hand, the immune histochemical method identified the etiology in 94.45% what was considered very expressive.

  6. Impact of enzyme loading on the efficacy and recovery of cellulolytic enzymes immobilized on enzymogel nanoparticles.

    Science.gov (United States)

    Samaratunga, Ashani; Kudina, Olena; Nahar, Nurun; Zakharchenko, Andrey; Minko, Sergiy; Voronov, Andriy; Pryor, Scott W

    2015-03-01

    Cellulase and β-glucosidase were adsorbed on a polyacrylic acid polymer brush grafted on silica nanoparticles to produce enzymogels as a form of enzyme immobilization. Enzyme loading on the enzymogels was increased to a saturation level of approximately 110 μg (protein) mg(-1) (particle) for each enzyme. Enzymogels with varied enzyme loadings were then used to determine the impact on hydrolysis rate and enzyme recovery. Soluble sugar concentrations during the hydrolysis of filter paper and Solka-Floc with the enzymogels were 45 and 53%, respectively, of concentrations when using free cellulase. β-Glucosidase enzymogels showed lower performance; hydrolyzate glucose concentrations were just 38% of those using free enzymes. Increasing enzyme loading on the enzymogels did not reduce net efficacy for cellulase and improved efficacy for β-glucosidase. The use of free cellulases and cellulase enzymogels resulted in hydrolyzates with different proportions of cellobiose and glucose, suggesting differential attachment or efficacy of endoglucanases, exoglucanases, and β-glucosidases present in cellulase mixtures. When loading β-glucosidase individually, higher enzyme loadings on the enzymogels produced higher hydrolyzate glucose concentrations. Approximately 96% of cellulase and 66 % of β-glucosidase were recovered on the enzymogels, while enzyme loading level did not impact recovery for either enzyme.

  7. Evolutionarily conserved substrate substructures for automated annotation of enzyme superfamilies.

    Directory of Open Access Journals (Sweden)

    Ranyee A Chiang

    2008-08-01

    Full Text Available The evolution of enzymes affects how well a species can adapt to new environmental conditions. During enzyme evolution, certain aspects of molecular function are conserved while other aspects can vary. Aspects of function that are more difficult to change or that need to be reused in multiple contexts are often conserved, while those that vary may indicate functions that are more easily changed or that are no longer required. In analogy to the study of conservation patterns in enzyme sequences and structures, we have examined the patterns of conservation and variation in enzyme function by analyzing graph isomorphisms among enzyme substrates of a large number of enzyme superfamilies. This systematic analysis of substrate substructures establishes the conservation patterns that typify individual superfamilies. Specifically, we determined the chemical substructures that are conserved among all known substrates of a superfamily and the substructures that are reacting in these substrates and then examined the relationship between the two. Across the 42 superfamilies that were analyzed, substantial variation was found in how much of the conserved substructure is reacting, suggesting that superfamilies may not be easily grouped into discrete and separable categories. Instead, our results suggest that many superfamilies may need to be treated individually for analyses of evolution, function prediction, and guiding enzyme engineering strategies. Annotating superfamilies with these conserved and reacting substructure patterns provides information that is orthogonal to information provided by studies of conservation in superfamily sequences and structures, thereby improving the precision with which we can predict the functions of enzymes of unknown function and direct studies in enzyme engineering. Because the method is automated, it is suitable for large-scale characterization and comparison of fundamental functional capabilities of both characterized

  8. Evolutionarily conserved substrate substructures for automated annotation of enzyme superfamilies.

    Science.gov (United States)

    Chiang, Ranyee A; Sali, Andrej; Babbitt, Patricia C

    2008-08-01

    The evolution of enzymes affects how well a species can adapt to new environmental conditions. During enzyme evolution, certain aspects of molecular function are conserved while other aspects can vary. Aspects of function that are more difficult to change or that need to be reused in multiple contexts are often conserved, while those that vary may indicate functions that are more easily changed or that are no longer required. In analogy to the study of conservation patterns in enzyme sequences and structures, we have examined the patterns of conservation and variation in enzyme function by analyzing graph isomorphisms among enzyme substrates of a large number of enzyme superfamilies. This systematic analysis of substrate substructures establishes the conservation patterns that typify individual superfamilies. Specifically, we determined the chemical substructures that are conserved among all known substrates of a superfamily and the substructures that are reacting in these substrates and then examined the relationship between the two. Across the 42 superfamilies that were analyzed, substantial variation was found in how much of the conserved substructure is reacting, suggesting that superfamilies may not be easily grouped into discrete and separable categories. Instead, our results suggest that many superfamilies may need to be treated individually for analyses of evolution, function prediction, and guiding enzyme engineering strategies. Annotating superfamilies with these conserved and reacting substructure patterns provides information that is orthogonal to information provided by studies of conservation in superfamily sequences and structures, thereby improving the precision with which we can predict the functions of enzymes of unknown function and direct studies in enzyme engineering. Because the method is automated, it is suitable for large-scale characterization and comparison of fundamental functional capabilities of both characterized and uncharacterized

  9. Enzymes- An Existing and Promising Tool of Food Processing Industry.

    Science.gov (United States)

    Ray, Lalitagauri; Pramanik, Sunita; Bera, Debabrata

    2016-01-01

    The enzyme catalyzed process technology has enormous potential in the food sectors as indicated by the recent patents studies. It is very well realized that the adaptation of the enzyme catalyzed process depends on the availability of enzyme in affordable prices. Enzymes may be used in different food sectors like dairy, fruits & vegetable processing, meat tenderization, fish processing, brewery and wine making, starch processing and many other. Commercially only a small number of enzymes are used because of several factors including instability of enzymes during processing and high cost. More and more enzymes for food technology are now derived from specially selected or genetically modified microorganisms grown in industrial scale fermenters. Enzymes with microbial source have commercial advantages of using microbial fermentation rather than animal and plant extraction to produce food enzymes. At present only a relatively small number of enzymes are used commercially in food processing. But the number is increasing day by day and field of application will be expanded more and more in near future. The purpose of this review is to describe the practical applications of enzymes in the field of food processing.

  10. Enzyme mechanisms for pyruvate-to-lactate flux attenuation: a study of Sherpas, Quechuas, and hummingbirds.

    Science.gov (United States)

    Hochachka, P W; Stanley, C; McKenzie, D C; Villena, A; Monge, C

    1992-10-01

    During incremental exercise to fatigue under hypobaric hypoxia, Andean Quechua natives form and accumulate less plasma lactate than do lowlanders under similar conditions. This phenomenon of low lactate accumulation despite hypobaric hypoxia, first discovered some half century ago, is known in Quechuas to be largely unaffected by acute exposure to hypoxia or by acclimatization to sea level conditions. Earlier Nuclear Magnetic Resonance (NMR) spectroscopy and metabolic biochemistry studies suggest that closer coupling of energy demand and energy supply in Quechuas allows given changes in work rate with relatively modest changes in muscle adenylate and phosphagen concentrations, thus tempering the activation of glycolytic flux to pyruvate--a coarse control mechanism operating at the level of overall pathway flux. Later studies of enzyme activities in skeletal muscles of Quechuas and of Sherpas have identified a finely-tuned control mechanism which by adaptive modifications of a few key enzymes apparently serves to specifically attenuate pyruvate flux to lactate.

  11. BAKERY ENZYMES IN CEREAL TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    Václav Koman

    2012-10-01

    Full Text Available Normal 0 21 false false false SK X-NONE X-NONE Bread is the most common and traditional food in the world. For years, enzymes such as malt and fungal alpha-amylase have been used in bread making. Due to the changes in the baking industry and the ever-increasing demand for more natural products, enzymes have gained real importance in bread-making. If an enzyme is added, it is often destroyed by the heat during the baking process. For generations, enzymes have been used for the improvement of texture and appearance, enhancement of nutritional values and generation of appealing flavours and aromas. Enzymes used in bakery industry constitute nearly one third of the market. The bakery products have undergone radical improvements in quality over the past years in terms of flavour, texture and shelf-life. The the biggest contributor for these improvementsis the usage of enzymes. Present work seeks to systematically describe bakery enzymes, their classification, benefits, usage and chemical reactions in the bread making process.doi:10.5219/193

  12. Effect of cadmium on lung lysosomal enzymes in vitro

    International Nuclear Information System (INIS)

    Giri, S.N.; Hollinger, M.A.

    1995-01-01

    Labilization of lysosomal enzymes is often associated with the general process of inflammation. The present study investigated the effect of the pneumotoxin cadmium on the release and activity of two lung lysosomal enzymes. Incubation of rat lung lysosomes with cadmium resulted in the release of β-glucuronidase but not acid phosphatase. The failure to ''release'' acid phosphatase appears to be the result of a direct inhibitory effect of cadmium on this enzyme. The K I for cadmium was determined to be 26.3 μM. The differential effect of cadmium on these two lysosomal enzymes suggests that caution should be exercised in selecting the appropriate enzyme marker for assessing lysosomal fragility in the presence of this toxicant. Furthermore, the differential basal release rate of the two enzymes from lung lysosomes may reflect the cellular heterogeneity of the lung. (orig.)

  13. Crosslinked Enzyme Aggregates in Hierarchically-Ordered Mesoporous Silica: A Simple and Effective Method for Enzyme Stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Moon Il; Kim, Jungbae; Lee, Jinwoo; Jia, Hongfei; Na, Hyon Bin; Youn, Jongkyu; Kwak, Ja Hun; Dohnalkova, Alice; Grate, Jay W.; Wang, Ping; Hyeon, Taeghwan; Park, Hyun-Gyu; Chang, Ho Nam

    2007-02-01

    alpha-chymotrypsin (CT) and lipase (LP) were immobilized in hierarchically-ordered mesocellular mesoporous silica (HMMS) in a simple but effective way for the enzyme stabilization, which was achieved by the enzyme adsorption followed by glutaraldehyde (GA) crosslinking. This resulted in the formation of nanometer scale crosslinked enzyme aggregates (CLEAs) entrapped in the mesocellular pores of HMMS (37 nm), which did not leach out of HMMS through narrow mesoporous channels (13 nm). CLEA of alpha-chymotrypsin (CLEA-CT) in HMMS showed a high enzyme loading capacity and significantly increased enzyme stability. No activity decrease of CLEA-CT was observed for two weeks under even rigorously shaking condition, while adsorbed CT in HMMS and free CT showed a rapid inactivation due to the enzyme leaching and presumably autolysis, respectively. With the CLEA-CT in HMMS, however, there was no tryptic digestion observed suggesting that the CLEA-CT is not susceptible to autolysis. Moreover, CLEA of lipase (CLEA-LP) in HMMS retained 30% specific activity of free lipase with greatly enhanced stability. This work demonstrates that HMMS can be efficiently employed as host materials for enzyme immobilization leading to highly enhanced stability of the immobilized enzymes with high enzyme loading and activity.

  14. Quantitative comparison of catalytic mechanisms and overall reactions in convergently evolved enzymes: implications for classification of enzyme function.

    Science.gov (United States)

    Almonacid, Daniel E; Yera, Emmanuel R; Mitchell, John B O; Babbitt, Patricia C

    2010-03-12

    Functionally analogous enzymes are those that catalyze similar reactions on similar substrates but do not share common ancestry, providing a window on the different structural strategies nature has used to evolve required catalysts. Identification and use of this information to improve reaction classification and computational annotation of enzymes newly discovered in the genome projects would benefit from systematic determination of reaction similarities. Here, we quantified similarity in bond changes for overall reactions and catalytic mechanisms for 95 pairs of functionally analogous enzymes (non-homologous enzymes with identical first three numbers of their EC codes) from the MACiE database. Similarity of overall reactions was computed by comparing the sets of bond changes in the transformations from substrates to products. For similarity of mechanisms, sets of bond changes occurring in each mechanistic step were compared; these similarities were then used to guide global and local alignments of mechanistic steps. Using this metric, only 44% of pairs of functionally analogous enzymes in the dataset had significantly similar overall reactions. For these enzymes, convergence to the same mechanism occurred in 33% of cases, with most pairs having at least one identical mechanistic step. Using our metric, overall reaction similarity serves as an upper bound for mechanistic similarity in functional analogs. For example, the four carbon-oxygen lyases acting on phosphates (EC 4.2.3) show neither significant overall reaction similarity nor significant mechanistic similarity. By contrast, the three carboxylic-ester hydrolases (EC 3.1.1) catalyze overall reactions with identical bond changes and have converged to almost identical mechanisms. The large proportion of enzyme pairs that do not show significant overall reaction similarity (56%) suggests that at least for the functionally analogous enzymes studied here, more stringent criteria could be used to refine

  15. Quantitative comparison of catalytic mechanisms and overall reactions in convergently evolved enzymes: implications for classification of enzyme function.

    Directory of Open Access Journals (Sweden)

    Daniel E Almonacid

    2010-03-01

    Full Text Available Functionally analogous enzymes are those that catalyze similar reactions on similar substrates but do not share common ancestry, providing a window on the different structural strategies nature has used to evolve required catalysts. Identification and use of this information to improve reaction classification and computational annotation of enzymes newly discovered in the genome projects would benefit from systematic determination of reaction similarities. Here, we quantified similarity in bond changes for overall reactions and catalytic mechanisms for 95 pairs of functionally analogous enzymes (non-homologous enzymes with identical first three numbers of their EC codes from the MACiE database. Similarity of overall reactions was computed by comparing the sets of bond changes in the transformations from substrates to products. For similarity of mechanisms, sets of bond changes occurring in each mechanistic step were compared; these similarities were then used to guide global and local alignments of mechanistic steps. Using this metric, only 44% of pairs of functionally analogous enzymes in the dataset had significantly similar overall reactions. For these enzymes, convergence to the same mechanism occurred in 33% of cases, with most pairs having at least one identical mechanistic step. Using our metric, overall reaction similarity serves as an upper bound for mechanistic similarity in functional analogs. For example, the four carbon-oxygen lyases acting on phosphates (EC 4.2.3 show neither significant overall reaction similarity nor significant mechanistic similarity. By contrast, the three carboxylic-ester hydrolases (EC 3.1.1 catalyze overall reactions with identical bond changes and have converged to almost identical mechanisms. The large proportion of enzyme pairs that do not show significant overall reaction similarity (56% suggests that at least for the functionally analogous enzymes studied here, more stringent criteria could be used to

  16. MD study of pyrimidine base damage on DNA and its recognition by repair enzyme

    International Nuclear Information System (INIS)

    Pinak, M.

    2000-01-01

    The molecular dynamics (MD) simulation was used on the study of two specific damages of pyrimidine bases of DNA. Pyrimidine bases are major targets either of free radicals induced by ionizing radiation in DNA surrounding environment or UV radiation. Thymine dimer (TD) is UV induced damage, in which two neighboring thymines in one strand are joined by covalent bonds of C(5)-C(5) and C(6)-C(6) atoms of thymines. Thymine glycol (TG) is ionizing radiation induced damage in which the free water radical adds to unsaturated bond C(5)-C(6) of thymine. Both damages are experimentally suggested to be mutagenetic and carcinogenic unless properly repaired by repair enzymes. In the case of MD of TD, there is detected strong kink around the TD site that is not observed in native DNA. In addition there is observed the different value of electrostatic energy at the TD site - negative '-10 kcal/mol', in contrary to nearly neutral value of native thymine site. Structural changes and specific electrostatic energy - seems to be important for proper recognition of TD damaged site, formation of DNA-enzyme complex and thus for subsequent repair of DNA. In the case of TG damaged DNA there is major structural distortion at the TG site, mainly the increased distance between TG and the C5' of adjacent nucleotide. This enlarged gap between the neighboring nucleotides may prevent the insertion of complementary base during replication causing the replication process to stop. In which extend this structural feature together with energy properties of TG contributes to the proper recognition of TG by repair enzyme Endonuclease III is subject of further computational MD study. (author)

  17. Cell age dependent variations in oxidative protective enzymes

    International Nuclear Information System (INIS)

    Blakely, E.A.; Chang, P.Y.; Lommel, L.; Tobias, C.A.

    1986-01-01

    Activity levels of antioxidant enzymes were correlated before and after heavy-ion exposures with cellular radiosensitivity. In preliminary feasibility experiments with human T-1 cells relatively high antioxidant enzyme levels were shown in the unirradiated G 1 phase prior to the normal DNA synthetic phase. Endogenous cellular levels of three antioxidant enzymes were measured at various times in the unirradiated human T-1 cell division cycle. The enzymes measured were: catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSHPX). Unlike the case in Chinese hamster V79 cells the early data with the synchronized human cell show that in very early G 1 phase (e.g., approximately 1.5 hours after mitotic selection) there are significant peaks in the levels (U/mg cell protein) of both CAT and SOD. Both enzymes show increases as the unirradiated cells progressed from mitosis into G 1 phase while the levels of GSHPX measured in duplicate samples were somewhat more variable than was the case for the other two enzymes. Studies were made in collaboration with the Armed Forces Radiobiology Research Institute

  18. Delayed effects of radiation on enzymes in erythrocytes

    International Nuclear Information System (INIS)

    Li Jinying; Zhang Weiping; Liu Benti

    1998-01-01

    Objective: To study the delayed effects of radiation on the enzymes in erythrocytes. Methods: The activity of 8 enzymes, related glycolysis, hexose monophosphate shunt, nucleotide metabolism, redox reaction and esterase in erythrocytes of five patients with bone marrow form of acute radiation sickness (ARS) were assayed at 1,2,3 and 6 years after exposure to 60 Co radiation. Results: The decreased activities of glucose-6-phosphate dehydrogenase (G6PD), pyruvate kinase (PK), NADH-methemoglobin reductase (MR) during the stage of crisis and of acetylcholinesterase (ACE) during the stage of convalescence were recovered to varying extent, whereas the lowered activities of the first three enzymes in some cases remained unchanged. There was no correlation between the enzyme activity and the radiation dose as well as the age of the patients. Conclusion: It is demonstrated that the delayed effects of radiation damage to erythrocyte enzymes are most significant in PK of glycolysis, G6PD of hexose monophosphate shunt and MR of redox reaction. It is suggested that the genes related to the synthesis of erythrocyte enzymes may be damaged by radiation

  19. Ligninolytic enzyme activities in mycelium of some wild and ...

    African Journals Online (AJOL)

    Lignin is probably one of the most recalcitrant compounds synthesized by plants. This compound is degraded by few microorganisms. White-rot fungi have been extensively studied due to its powerful ligninolytic enzymes. In this study, ligninolytic enzyme activities of different fungal species (six commercial and 13 wild) were ...

  20. Spectroscopic studies of copper enzymes

    International Nuclear Information System (INIS)

    Dooley, D.M.; Moog, R.; Zumft, W.; Koenig, S.H.; Scott, R.A.; Cote, C.E.; McGuirl, M.

    1986-01-01

    Several spectroscopic methods, including absorption, circular dichroism (CD), magnetic CD (MCD), X-ray absorption, resonance Raman, EPR, NMR, and quasi-elastic light-scattering spectroscopy, have been used to probe the structures of copper-containing amine oxidases, nitrite reductase, and nitrous oxide reductase. The basic goals are to determine the copper site structure, electronic properties, and to generate structure-reactivity correlations. Collectively, the results on the amine oxidases permit a detailed model for the Cu(II) sites in these enzymes to be constructed that, in turn, rationalizes the ligand-binding chemistry. Resonance Raman spectra of the phenylhydrazine and 2,4-dinitrophenyl-hydrazine derivatives of bovine plasma amine oxidase and models for its organic cofactor, e.g. pyridoxal, methoxatin, are most consistent with methoxatin being the intrinsic cofactor. The structure of the Cu(I) forms of the amine oxidases have been investigated by X-ray absorption spectroscopy (XAS); the copper coordination geometry is significantly different in the oxidized and reduced forms. Some anomalous properties of the amine oxidases in solution are explicable in terms of their reversible aggregation, which the authors have characterized via light scattering. Nitrite and nitrous oxide reductases display several novel spectral properties. The data suggest that new types of copper sites are present

  1. Immobilized enzymes and cells

    Energy Technology Data Exchange (ETDEWEB)

    Bucke, C; Wiseman, A

    1981-04-04

    This article reviews the current state of the art of enzyme and cell immobilization and suggests advances which might be made during the 1980's. Current uses of immobilized enzymes include the use of glucoamylase in the production of glucose syrups from starch and glucose isomerase in the production of high fructose corn syrup. Possibilities for future uses of immobilized enzymes and cells include the utilization of whey and the production of ethanol.

  2. Selection and production of insoluble xylan hydrolyzing enzyme by ...

    African Journals Online (AJOL)

    Jane

    2011-03-07

    Mar 7, 2011 ... The effect of pH and temperature on the enzyme activity and stability of crude enzyme produced by T. lanuginosus THKU 56 were investigated. To study the effect of pH on activity, the reaction mixture of 0.5 ml of enzyme and 0.5 ml of 1% insoluble oat spelt xylan in 50 mM buffers with various pH values ...

  3. Implantable enzyme amperometric biosensors.

    Science.gov (United States)

    Kotanen, Christian N; Moussy, Francis Gabriel; Carrara, Sandro; Guiseppi-Elie, Anthony

    2012-05-15

    The implantable enzyme amperometric biosensor continues as the dominant in vivo format for the detection, monitoring and reporting of biochemical analytes related to a wide range of pathologies. Widely used in animal studies, there is increasing emphasis on their use in diabetes care and management, the management of trauma-associated hemorrhage and in critical care monitoring by intensivists in the ICU. These frontier opportunities demand continuous indwelling performance for up to several years, well in excess of the currently approved seven days. This review outlines the many challenges to successful deployment of chronically implantable amperometric enzyme biosensors and emphasizes the emerging technological approaches in their continued development. The foreign body response plays a prominent role in implantable biotransducer failure. Topics considering the approaches to mitigate the inflammatory response, use of biomimetic chemistries, nanostructured topographies, drug eluting constructs, and tissue-to-device interface modulus matching are reviewed. Similarly, factors that influence biotransducer performance such as enzyme stability, substrate interference, mediator selection and calibration are reviewed. For the biosensor system, the opportunities and challenges of integration, guided by footprint requirements, the limitations of mixed signal electronics, and power requirements, has produced three systems approaches. The potential is great. However, integration along the multiple length scales needed to address fundamental issues and integration across the diverse disciplines needed to achieve success of these highly integrated systems, continues to be a challenge in the development and deployment of implantable amperometric enzyme biosensor systems. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Spatial distribution of enzyme driven reactions at micro-scales

    Science.gov (United States)

    Kandeler, Ellen; Boeddinghaus, Runa; Nassal, Dinah; Preusser, Sebastian; Marhan, Sven; Poll, Christian

    2017-04-01

    Studies of microbial biogeography can often provide key insights into the physiologies, environmental tolerances, and ecological strategies of soil microorganisms that dominate in natural environments. In comparison with aquatic systems, soils are particularly heterogeneous. Soil heterogeneity results from the interaction of a hierarchical series of interrelated variables that fluctuate at many different spatial and temporal scales. Whereas spatial dependence of chemical and physical soil properties is well known at scales ranging from decimetres to several hundred metres, the spatial structure of soil enzymes is less clear. Previous work has primarily focused on spatial heterogeneity at a single analytical scale using the distribution of individual cells, specific types of organisms or collective parameters such as bacterial abundance or total microbial biomass. There are fewer studies that have considered variations in community function and soil enzyme activities. This presentation will give an overview about recent studies focusing on spatial pattern of different soil enzymes in the terrestrial environment. Whereas zymography allows the visualization of enzyme pattern in the close vicinity of roots, micro-sampling strategies followed by MUF analyses clarify micro-scale pattern of enzymes associated to specific microhabitats (micro-aggregates, organo-mineral complexes, subsoil compartments).

  5. Molecular Imaging of Hydrolytic Enzymes Using PET and SPECT.

    Science.gov (United States)

    Rempel, Brian P; Price, Eric W; Phenix, Christopher P

    2017-01-01

    Hydrolytic enzymes are a large class of biological catalysts that play a vital role in a plethora of critical biochemical processes required to maintain human health. However, the expression and/or activity of these important enzymes can change in many different diseases and therefore represent exciting targets for the development of positron emission tomography (PET) and single-photon emission computed tomography (SPECT) radiotracers. This review focuses on recently reported radiolabeled substrates, reversible inhibitors, and irreversible inhibitors investigated as PET and SPECT tracers for imaging hydrolytic enzymes. By learning from the most successful examples of tracer development for hydrolytic enzymes, it appears that an early focus on careful enzyme kinetics and cell-based studies are key factors for identifying potentially useful new molecular imaging agents.

  6. Structural studies of cinnamoyl-CoA reductase and cinnamyl-alcohol dehydrogenase, key enzymes of monolignol biosynthesis.

    Science.gov (United States)

    Pan, Haiyun; Zhou, Rui; Louie, Gordon V; Mühlemann, Joëlle K; Bomati, Erin K; Bowman, Marianne E; Dudareva, Natalia; Dixon, Richard A; Noel, Joseph P; Wang, Xiaoqiang

    2014-09-01

    The enzymes cinnamoyl-CoA reductase (CCR) and cinnamyl alcohol dehydrogenase (CAD) catalyze the two key reduction reactions in the conversion of cinnamic acid derivatives into monolignol building blocks for lignin polymers in plant cell walls. Here, we describe detailed functional and structural analyses of CCRs from Medicago truncatula and Petunia hybrida and of an atypical CAD (CAD2) from M. truncatula. These enzymes are closely related members of the short-chain dehydrogenase/reductase (SDR) superfamily. Our structural studies support a reaction mechanism involving a canonical SDR catalytic triad in both CCR and CAD2 and an important role for an auxiliary cysteine unique to CCR. Site-directed mutants of CAD2 (Phe226Ala and Tyr136Phe) that enlarge the phenolic binding site result in a 4- to 10-fold increase in activity with sinapaldehyde, which in comparison to the smaller coumaraldehyde and coniferaldehyde substrates is disfavored by wild-type CAD2. This finding demonstrates the potential exploitation of rationally engineered forms of CCR and CAD2 for the targeted modification of monolignol composition in transgenic plants. Thermal denaturation measurements and structural comparisons of various liganded and unliganded forms of CCR and CAD2 highlight substantial conformational flexibility of these SDR enzymes, which plays an important role in the establishment of catalytically productive complexes of the enzymes with their NADPH and phenolic substrates. © 2014 American Society of Plant Biologists. All rights reserved.

  7. Enzyme clustering accelerates processing of intermediates through metabolic channeling

    Science.gov (United States)

    Castellana, Michele; Wilson, Maxwell Z.; Xu, Yifan; Joshi, Preeti; Cristea, Ileana M.; Rabinowitz, Joshua D.; Gitai, Zemer; Wingreen, Ned S.

    2015-01-01

    We present a quantitative model to demonstrate that coclustering multiple enzymes into compact agglomerates accelerates the processing of intermediates, yielding the same efficiency benefits as direct channeling, a well-known mechanism in which enzymes are funneled between enzyme active sites through a physical tunnel. The model predicts the separation and size of coclusters that maximize metabolic efficiency, and this prediction is in agreement with previously reported spacings between coclusters in mammalian cells. For direct validation, we study a metabolic branch point in Escherichia coli and experimentally confirm the model prediction that enzyme agglomerates can accelerate the processing of a shared intermediate by one branch, and thus regulate steady-state flux division. Our studies establish a quantitative framework to understand coclustering-mediated metabolic channeling and its application to both efficiency improvement and metabolic regulation. PMID:25262299

  8. Imbalance between pulmonary angiotensin-converting enzyme and angiotensin-converting enzyme 2 activity in acute respiratory distress syndrome

    NARCIS (Netherlands)

    Wösten-van Asperen, Roelie M.; Bos, Albert P.; Bem, Reinout A.; Dierdorp, Barbara S.; Dekker, Tamara; van Goor, Harry; Kamilic, Jelena; van der Loos, Chris M.; van den Berg, Elske; Bruijn, Martijn; van Woensel, Job B.; Lutter, René

    2013-01-01

    Angiotensin-converting enzyme and its effector peptide angiotensin II have been implicated in the pathogenesis of acute respiratory distress syndrome. Recently, angiotensin-converting enzyme 2 was identified as the counter-regulatory enzyme of angiotensin-converting enzyme that converts angiotensin

  9. Imbalance between pulmonary angiotensin-converting enzyme and angiotensin-converting enzyme 2 activity in acute respiratory distress syndrome

    NARCIS (Netherlands)

    Wosten-van Asperen, Roelie M.; Bos, Albert; Bem, Reinout A.; Dierdorp, Barbara S.; Dekker, Tamara; van Goor, Harry; Kamilic, Jelena; van der Loos, Chris M.; van den Berg, Elske; Bruijn, Martijn; van Woensel, Job B.; Lutter, Rene

    2013-01-01

    Objective: Angiotensin-converting enzyme and its effector peptide angiotensin II have been implicated in the pathogenesis of acute respiratory distress syndrome. Recently, angiotensin-converting enzyme 2 was identified as the counter-regulatory enzyme of angiotensin-converting enzyme that converts

  10. A study of the alkaline and acid phosphatase activities in acute uranium intoxication

    International Nuclear Information System (INIS)

    Bokova, N.; Pavlova, V.; Stancheva, Yu.; Khadzhirusev, S.; Kiradzhiev, G.

    1975-01-01

    Comparative study of the ability of the sodium salt of diethylbarbituric acid and acetazolamide to protect the kidneys is conducted under conditions of acute uranium intoxication in rats. The parameters studied are alkaline and acid phosphatase activities in the serum and urine and phosphatase activity in the kidneys (histochemically as described by Gomori) followed up until the 30th day after the total uranyl acetate dose was reached (2 or 7 mg per kg bodyweight). Either compound exerted only minor effect on serum alkaline phosphatase activity. Sodium diethylbarbiturate induced distinct fluctuations in urinary alkaline phosphatase activity throughout the entire study period, but the differences never reached statistical significance. Acetazolamide caused essential decrease in urinary alkaline phosphatase activity. In either case renal tissue protection from the action of the uranyl ion may be suggested. This assumption is supported by the histochemical analysis. The compounds appeared to have no effect on serum acid phosphatase activity which showed high variability both in control and in treated rats. (Ch.K.)

  11. Fluorometric Assessment Of Lysosomal Enzymes In Garlic Oil ...

    African Journals Online (AJOL)

    The effect of Garlic oil on Lysosomal enzymes in streptozotocin-induced diabetic rats were investigated fluorometrically. The serum lysosomal enzymes assayed include β-glucuronidase, N-acetylglucosaminidase (NAG) β-D-galactosidase and α-D-galactosidase. The results of the study in nMole-4Mu/hr/ml show that ...

  12. Enzymatic solubilisation and degradation of soybean fibre demonstrated by viscosity, fibre analysis and microscopy

    DEFF Research Database (Denmark)

    Ravn, Jonas Laukkonen; Martens, Helle Juel; Pettersson, Dan

    2015-01-01

    The effect of a commercial multienzyme product obtained by fermentation from Aspergillus aculeatus on soybean and soybean meal was investigated using viscosity measurements, dietary fibre component analysis and different microscopy techniques utilizing histochemical dyes and antibody labelling....... The results obtained demonstrated a strong viscosity reducing effect of the enzyme preparation on soluble galactomannan and xyloglucan polysaccharides and in addition non-starch polysaccharide analysis demonstrated a notable solubilisation of all polysaccharide constituents. The degradation...

  13. Magnetic enzyme reactors for isolation and study of heterogeneous glycoproteins

    Czech Academy of Sciences Publication Activity Database

    Korecká, L.; Ježová, J.; Bílková, Z.; Beneš, Milan J.; Horák, Daniel; Hradcová, O.; Slováková, M.; Viovy, J.-L.

    2005-01-01

    Roč. 293, č. 1 (2005), s. 349-357 ISSN 0304-8853 R&D Projects: GA ČR(CZ) GA203/02/0023 Grant - others:EU project(XE) QLG-CT-2001-01903 Keywords : magnetic enzyme reactor * trypsin * chymotrypsin Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.985, year: 2005

  14. DGAT enzymes and triacylglycerol biosynthesis

    Science.gov (United States)

    Yen, Chi-Liang Eric; Stone, Scot J.; Koliwad, Suneil; Harris, Charles; Farese, Robert V.

    2008-01-01

    Triacylglycerols (triglycerides) (TGs) are the major storage molecules of metabolic energy and FAs in most living organisms. Excessive accumulation of TGs, however, is associated with human diseases, such as obesity, diabetes mellitus, and steatohepatitis. The final and the only committed step in the biosynthesis of TGs is catalyzed by acyl-CoA:diacylglycerol acyltransferase (DGAT) enzymes. The genes encoding two DGAT enzymes, DGAT1 and DGAT2, were identified in the past decade, and the use of molecular tools, including mice deficient in either enzyme, has shed light on their functions. Although DGAT enzymes are involved in TG synthesis, they have distinct protein sequences and differ in their biochemical, cellular, and physiological functions. Both enzymes may be useful as therapeutic targets for diseases. Here we review the current knowledge of DGAT enzymes, focusing on new advances since the cloning of their genes, including possible roles in human health and diseases. PMID:18757836

  15. Independent Evolution of Six Families of Halogenating Enzymes.

    Science.gov (United States)

    Xu, Gangming; Wang, Bin-Gui

    2016-01-01

    Halogenated natural products are widespread in the environment, and the halogen atoms are typically vital to their bioactivities. Thus far, six families of halogenating enzymes have been identified: cofactor-free haloperoxidases (HPO), vanadium-dependent haloperoxidases (V-HPO), heme iron-dependent haloperoxidases (HI-HPO), non-heme iron-dependent halogenases (NI-HG), flavin-dependent halogenases (F-HG), and S-adenosyl-L-methionine (SAM)-dependent halogenases (S-HG). However, these halogenating enzymes with similar biological functions but distinct structures might have evolved independently. Phylogenetic and structural analyses suggest that the HPO, V-HPO, HI-HPO, NI-HG, F-HG, and S-HG enzyme families may have evolutionary relationships to the α/β hydrolases, acid phosphatases, peroxidases, chemotaxis phosphatases, oxidoreductases, and SAM hydroxide adenosyltransferases, respectively. These halogenating enzymes have established sequence homology, structural conservation, and mechanistic features within each family. Understanding the distinct evolutionary history of these halogenating enzymes will provide further insights into the study of their catalytic mechanisms and halogenation specificity.

  16. Study of High Sensitive-CRP and Cardiac Marker Enzymes in Acute Coronary Syndrome

    Directory of Open Access Journals (Sweden)

    Srikrishna R,

    2015-04-01

    Full Text Available Background: Inflammation has been proposed as a contributor to different stages in the pathogenesis of Coronary Heart Disease (CHD. High sensitive C-Reactive Protein (hs-CRP, an acute-phase plasma protein synthesized by the liver, is the most extensively studied systemic marker of inflammation. Elevated hsCRP concentrations early in Acute Coronary Syndrome (ACS, prior to the tissue necrosis, may be a surrogate marker for cardiovascular co-morbidities. The cardiac marker enzymes Creatine Kinase myocardial bound (CK-MB, Aspartate Aminotransferase (AST and lactate dehydrogenase (LDH have been known to be increased in coronary artery diseases. Objective: The aim of the study was to measure hs-CRP levels and other cardiac marker enzymes in ACS patients and to compare the levels of hs-CRP with other cardiac marker enzymes between ST Elevation Myocardial Infarction (STEMI and Non-ST Elevation Myocardial Infarction (NSTEMI patients. Material and Methods: The study group consisted of 207 consecutive patients admitted to Sri Siddhartha Medical College Hospital within the first 6 hours from the onset of chest pain. Patients were diagnosed as Unstable Angina (UA, (n=84; STEMI (n=63 and NSTEMI (n=60. ACS patients were compared with 211 healthy age and sex matched controls. Hs-CRP, CK-MB, AST and LDH levels were measured by standard methods in both groups at baseline and forcases at 36-48 hours i.e. Peak levels. Results: ACS patients had significantly (p<0.05 higher levels of hs-CRP, CKMB, AST and LDH in comparison to controls at baseline. Hs-CRP, CK-MB, AST and LDH levels were significantly higher in STEMI patients compared to NSTEMI patients (p<0.05 at baseline. There was a significant difference regarding peak hs-CRP levels between the two groups, as STEMI patients had significantly higher peak hs-CRP levels compared to NSTEMI patients (p<0.05. Conclusion: STEMI patients have significantly higher peak hsCRP levels compared to NSTEMI patients. These data

  17. Genetic polymorphisms of drug-metabolizing cytochrome P450 enzymes in cynomolgus and rhesus monkeys and common marmosets in preclinical studies for humans.

    Science.gov (United States)

    Uno, Yasuhiro; Uehara, Shotaro; Yamazaki, Hiroshi

    2017-12-23

    Cynomolgus monkeys (Macaca fascicularis, Old World Monkeys) and common marmosets (Callithrix jacchus, New World Monkeys) have been widely, and expectedly, used as non-human primate models in drug development studies. Major drug-metabolizing cytochrome P450 (P450) enzymes information is now available that supports these primate species as animal models, and it is established that multiple forms of cynomolgus monkey and common marmoset P450 enzymes have generally similar substrate recognition functionality to human P450 enzymes. This research update provides information on genetic polymorphisms of P450 enzymes in cynomolgus monkey and common marmoset like human P450 enzymes. Information on rhesus monkeys (Macaca mulatta), another macaque species used in drug metabolism studies, is also included for comparison. Among a variety of cynomolgus monkey P450 variants investigated, typical examples include individual pharmacokinetic data for efavirenz and R-warfarin associated with cynomolgus monkey P450 2C9 (formerly 2C43) and 2C19 (2C75) variants, respectively, and for R-omeprazole and S-warfarin associated with marmoset P450 2C19 variants. These findings provide a foundation for understanding the individual pharmacokinetic and toxicological results in non-human primates as preclinical models and will help to further support understanding of molecular mechanisms of human P450 function. In addition to these polymorphic P450 enzymes, effects of aging on some drug clearances mediated by cynomolgus monkey and common marmoset P450 enzymes were found in elder animals or animals pretreated with rifampicin. This review describes genetic and acquired individual differences in cynomolgus monkey and common marmoset P450 enzymes involved in drug oxidation associated with pharmacological and/or toxicological effects. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. The Endosome-associated Deubiquitinating Enzyme USP8 Regulates BACE1 Enzyme Ubiquitination and Degradation.

    Science.gov (United States)

    Yeates, Eniola Funmilayo Aduke; Tesco, Giuseppina

    2016-07-22

    The β-site amyloid precursor protein-cleaving enzyme (BACE1) is the rate-limiting enzyme in the production of amyloid-β, the toxic peptide that accumulates in the brain of subjects affected by Alzheimer disease. Our previous studies have shown that BACE1 is degraded via the lysosomal pathway and that that depletion of the trafficking molecule Golgi-localized γ-ear-containing ARF-binding protein 3 (GGA3) results in increased BACE1 levels and activity because of impaired lysosomal degradation. We also determined that GGA3 regulation of BACE1 levels requires its ability to bind ubiquitin. Accordingly, we reported that BACE1 is ubiquitinated at lysine 501 and that lack of ubiquitination at lysine 501 produces BACE1 stabilization. Ubiquitin conjugation is a reversible process mediated by deubiquitinating enzymes. The ubiquitin-specific peptidase 8 (USP8), an endosome-associated deubiquitinating enzyme, regulates the ubiquitination, trafficking, and lysosomal degradation of several plasma membrane proteins. Here, we report that RNAi-mediated depletion of USP8 reduced levels of both ectopically expressed and endogenous BACE1 in H4 human neuroglioma cells. Moreover, USP8 depletion increased BACE1 ubiquitination, promoted BACE1 accumulation in the early endosomes and late endosomes/lysosomes, and decreased levels of BACE1 in the recycling endosomes. We also found that decreased BACE1 protein levels were accompanied by a decrease in BACE1-mediated amyloid precursor protein cleavage and amyloid-β levels. Our findings demonstrate that USP8 plays a key role in the trafficking and degradation of BACE1 by deubiquitinating lysine 501. These studies suggest that therapies able to accelerate BACE1 degradation (e.g. by increasing BACE1 ubiquitination) may represent a potential treatment for Alzheimer disease. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. The Endosome-associated Deubiquitinating Enzyme USP8 Regulates BACE1 Enzyme Ubiquitination and Degradation*

    Science.gov (United States)

    Yeates, Eniola Funmilayo Aduke; Tesco, Giuseppina

    2016-01-01

    The β-site amyloid precursor protein-cleaving enzyme (BACE1) is the rate-limiting enzyme in the production of amyloid-β, the toxic peptide that accumulates in the brain of subjects affected by Alzheimer disease. Our previous studies have shown that BACE1 is degraded via the lysosomal pathway and that that depletion of the trafficking molecule Golgi-localized γ-ear-containing ARF-binding protein 3 (GGA3) results in increased BACE1 levels and activity because of impaired lysosomal degradation. We also determined that GGA3 regulation of BACE1 levels requires its ability to bind ubiquitin. Accordingly, we reported that BACE1 is ubiquitinated at lysine 501 and that lack of ubiquitination at lysine 501 produces BACE1 stabilization. Ubiquitin conjugation is a reversible process mediated by deubiquitinating enzymes. The ubiquitin-specific peptidase 8 (USP8), an endosome-associated deubiquitinating enzyme, regulates the ubiquitination, trafficking, and lysosomal degradation of several plasma membrane proteins. Here, we report that RNAi-mediated depletion of USP8 reduced levels of both ectopically expressed and endogenous BACE1 in H4 human neuroglioma cells. Moreover, USP8 depletion increased BACE1 ubiquitination, promoted BACE1 accumulation in the early endosomes and late endosomes/lysosomes, and decreased levels of BACE1 in the recycling endosomes. We also found that decreased BACE1 protein levels were accompanied by a decrease in BACE1-mediated amyloid precursor protein cleavage and amyloid-β levels. Our findings demonstrate that USP8 plays a key role in the trafficking and degradation of BACE1 by deubiquitinating lysine 501. These studies suggest that therapies able to accelerate BACE1 degradation (e.g. by increasing BACE1 ubiquitination) may represent a potential treatment for Alzheimer disease. PMID:27302062

  20. Angiotensin-Converting Enzymes Play a Dominant Role in Fertility

    Directory of Open Access Journals (Sweden)

    Fan Jin

    2013-10-01

    Full Text Available According to the World Health Organization, infertility, associated with metabolic syndrome, has become a global issue with a 10%–20% incidence worldwide. An accumulating body of evidence has shown that the renin–angiotensin system is involved in the fertility problems observed in some populations. Moreover, alterations in the expression of angiotensin-converting enzyme-1, angiotensin-converting enzyme-2, and angiotensin-converting enzyme-3 might be one of the most important mechanisms underlying both female and male infertility. However, as a pseudogene in humans, further studies are needed to explore whether the abnormal angiotensin-converting enzyme-3 gene could result in the problems of human reproduction. In this review, the relationship between angiotensin-converting enzymes and fertile ability is summarized, and a new procedure for the treatment of infertility is discussed.

  1. EVOLUTIONARY TRANSITIONS IN ENZYME ACTIVITY OF ANT FUNGUS GARDENS

    DEFF Research Database (Denmark)

    De Fine Licht, Henrik H; Schiøtt, Morten; Mueller, Ulrich G

    2010-01-01

    an association with a monophyletic clade of specialized symbionts. In conjunction with the transition to specialized symbionts, the ants advanced in colony size and social complexity. Here we provide a comparative study of the functional specialization in extracellular enzyme activities in fungus gardens across...... the attine phylogeny. We show that, relative to sister clades, gardens of higher-attine ants have enhanced activity of protein-digesting enzymes, whereas gardens of leaf-cutting ants also have increased activity of starch-digesting enzymes. However, the enzyme activities of lower-attine fungus gardens...... are targeted primarily towards partial degradation of plant cell walls, reflecting a plesiomorphic state of non-domesticated fungi. The enzyme profiles of the higher-attine and leaf-cutting gardens appear particularly suited to digest fresh plant materials and to access nutrients from live cells without major...

  2. Histochemical response of `Grande naine' plants inoculated with M. fijiensis and Bacillus pumilus CCIBP-C5 cell free filtrate

    Directory of Open Access Journals (Sweden)

    Eilyn Mena

    2015-04-01

    Full Text Available In recent years, interest has won biocontrol Mycosphaerella fijiensis with the use of microorganisms or their products. Nevertheless, the knowledge of the biochemical events involved in Musa- M. fijiensis-microorganism interaction, is still limited. The objective was to determine the histochemical response of `Grande naine' (Musa AAA plants inoculated or not with the pathogen in the presence of culture filtrate of Bacillus pumilus CCIBP-C5. For this, techniques that allow visualization of callose, superoxide anion, lignin and phenolic compounds in the early days post inoculation (dpi were used. As a result, at 6 dpi callose deposition were observed within the stomata in plants where the culture filtrate was applied regardless of the presence or absence of the pathogen. Furthermore, a blue halo was observed around stomas, indicative of the presence of superoxide anion. It was not possible to detect accumulation of lignin or phenolic compounds with the technique used. It was demonstrated the accumulation of biochemical compounds related to defense response of `Grande naine' plants to pathogen infection. Furthermore, it was shown that the plant responds in early infection with the use of bacterial culture filtrates. These results demonstrate the possible mechanism of induction of defense response in plants of Musa sp. in the presence of bacterial culture filtrate. Key words: Black Sigatoka, callose, lignin, phenols, superoxide anion

  3. Exquisite Enzyme-Fenton Biomimetic Catalysts for Hydroxyl Radical Production by Mimicking an Enzyme Cascade.

    Science.gov (United States)

    Zhang, Qi; Chen, Shuo; Wang, Hua; Yu, Hongtao

    2018-03-14

    Hydrogen peroxide (H 2 O 2 ) is a key reactant in the Fenton process. As a byproduct of enzymatic reaction, H 2 O 2 can be obtained via catalytical oxidation of glucose using glucose oxidase in the presence of O 2 . Another oxidation product (gluconic acid) can suitably adjust the microenvironmental pH contributing to the Fe 3+ /Fe 2+ cycle in the Fenton reaction. Enzymes are extremely efficient at catalyzing a variety of reactions with high catalytic activity, substrate specificity, and yields in living organisms. Inspired by the multiple functions of natural multienzyme systems, an exquisite nanozyme-modified α-FeOOH/porous carbon (PC) biomimetic catalyst constructed by in situ growth of glucose oxidase-mimicking Au nanoparticles and crystallization of adsorbed ferric ions within carboxyl into hierarchically PC is developed as an efficient enzyme-Fenton catalyst. The products (H 2 O 2 , ∼4.07 mmol·L -1 ) of the first enzymatic reaction are immediately used as substrates for the second Fenton-like reaction to generate the valuable • OH (∼96.84 μmol·L -1 ), thus mimicking an enzyme cascade pathway. α-FeOOH nanocrystals, attached by C-O-Fe bondings, are encapsulated into the mesoporous PC frameworks, facilitating the electron transfer between α-FeOOH and the PC support and greatly suppressing iron leaching. This study paves a new avenue for designing biomimetic enzyme-based Fenton catalysts mimicking a natural system for • OH production.

  4. DNA-Based Enzyme Reactors and Systems

    Directory of Open Access Journals (Sweden)

    Veikko Linko

    2016-07-01

    Full Text Available During recent years, the possibility to create custom biocompatible nanoshapes using DNA as a building material has rapidly emerged. Further, these rationally designed DNA structures could be exploited in positioning pivotal molecules, such as enzymes, with nanometer-level precision. This feature could be used in the fabrication of artificial biochemical machinery that is able to mimic the complex reactions found in living cells. Currently, DNA-enzyme hybrids can be used to control (multi-enzyme cascade reactions and to regulate the enzyme functions and the reaction pathways. Moreover, sophisticated DNA structures can be utilized in encapsulating active enzymes and delivering the molecular cargo into cells. In this review, we focus on the latest enzyme systems based on novel DNA nanostructures: enzyme reactors, regulatory devices and carriers that can find uses in various biotechnological and nanomedical applications.

  5. Cold-Adapted Enzymes

    Science.gov (United States)

    Georlette, D.; Bentahir, M.; Claverie, P.; Collins, T.; D'amico, S.; Delille, D.; Feller, G.; Gratia, E.; Hoyoux, A.; Lonhienne, T.; Meuwis, M.-a.; Zecchinon, L.; Gerday, Ch.

    In the last few years, increased attention has been focused on enzymes produced by cold-adapted micro-organisms. It has emerged that psychrophilic enzymes represent an extremely powerful tool in both protein folding investigations and for biotechnological purposes. Such enzymes are characterised by an increased thermosensitivity and, most of them, by a higher catalytic efficiency at low and moderate temperatures, when compared to their mesophilic counterparts. The high thermosensitivity probably originates from an increased flexibility of either a selected area of the molecular edifice or the overall protein structure, providing enhanced abilities to undergo conformational changes during catalysis at low temperatures. Structure modelling and recent crystallographic data have allowed to elucidate the structural parameters that could be involved in this higher resilience. It was demonstrated that each psychrophilic enzyme adopts its own adaptive strategy. It appears, moreover, that there is a continuum in the strategy of protein adaptation to temperature, as the previously mentioned structural parameters are implicated in the stability of thermophilic proteins. Additional 3D crystal structures, site-directed and random mutagenesis experiments should now be undertaken to further investigate the stability-flexibility-activity relationship.

  6. Lysosomal enzymes and their receptors in invertebrates: an evolutionary perspective.

    Science.gov (United States)

    Kumar, Nadimpalli Siva; Bhamidimarri, Poorna M

    2015-01-01

    Lysosomal biogenesis is an important process in eukaryotic cells to maintain cellular homeostasis. The key components that are involved in the biogenesis such as the lysosomal enzymes, their modifications and the mannose 6-phosphate receptors have been well studied and their evolutionary conservation across mammalian and non-mammalian vertebrates is clearly established. Invertebrate lysosomal biogenesis pathway on the other hand is not well studied. Although, details on mannose 6-phosphate receptors and enzymes involved in lysosomal enzyme modifications were reported earlier, a clear cut pathway has not been established. Recent research on the invertebrate species involving biogenesis of lysosomal enzymes suggests a possible conserved pathway in invertebrates. This review presents certain observations based on these processes that include biochemical, immunological and functional studies. Major conclusions include conservation of MPR-dependent pathway in higher invertebrates and recent evidence suggests that MPR-independent pathway might have been more prominent among lower invertebrates. The possible components of MPR-independent pathway that may play a role in lysosomal enzyme targeting are also discussed here.

  7. DEEPre: sequence-based enzyme EC number prediction by deep learning

    KAUST Repository

    Li, Yu

    2017-10-20

    Annotation of enzyme function has a broad range of applications, such as metagenomics, industrial biotechnology, and diagnosis of enzyme deficiency-caused diseases. However, the time and resource required make it prohibitively expensive to experimentally determine the function of every enzyme. Therefore, computational enzyme function prediction has become increasingly important. In this paper, we develop such an approach, determining the enzyme function by predicting the Enzyme Commission number.We propose an end-to-end feature selection and classification model training approach, as well as an automatic and robust feature dimensionality uniformization method, DEEPre, in the field of enzyme function prediction. Instead of extracting manuallycrafted features from enzyme sequences, our model takes the raw sequence encoding as inputs, extracting convolutional and sequential features from the raw encoding based on the classification result to directly improve the prediction performance. The thorough cross-fold validation experiments conducted on two large-scale datasets show that DEEPre improves the prediction performance over the previous state-of-the-art methods. In addition, our server outperforms five other servers in determining the main class of enzymes on a separate low-homology dataset. Two case studies demonstrate DEEPre\\'s ability to capture the functional difference of enzyme isoforms.The server could be accessed freely at http://www.cbrc.kaust.edu.sa/DEEPre.

  8. DEEPre: sequence-based enzyme EC number prediction by deep learning

    KAUST Repository

    Li, Yu; Wang, Sheng; Umarov, Ramzan; Xie, Bingqing; Fan, Ming; Li, Lihua; Gao, Xin

    2017-01-01

    Annotation of enzyme function has a broad range of applications, such as metagenomics, industrial biotechnology, and diagnosis of enzyme deficiency-caused diseases. However, the time and resource required make it prohibitively expensive to experimentally determine the function of every enzyme. Therefore, computational enzyme function prediction has become increasingly important. In this paper, we develop such an approach, determining the enzyme function by predicting the Enzyme Commission number.We propose an end-to-end feature selection and classification model training approach, as well as an automatic and robust feature dimensionality uniformization method, DEEPre, in the field of enzyme function prediction. Instead of extracting manuallycrafted features from enzyme sequences, our model takes the raw sequence encoding as inputs, extracting convolutional and sequential features from the raw encoding based on the classification result to directly improve the prediction performance. The thorough cross-fold validation experiments conducted on two large-scale datasets show that DEEPre improves the prediction performance over the previous state-of-the-art methods. In addition, our server outperforms five other servers in determining the main class of enzymes on a separate low-homology dataset. Two case studies demonstrate DEEPre's ability to capture the functional difference of enzyme isoforms.The server could be accessed freely at http://www.cbrc.kaust.edu.sa/DEEPre.

  9. Lipid peroxidation and antioxidant enzymes in male infertility.

    Directory of Open Access Journals (Sweden)

    Dandekar S

    2002-07-01

    Full Text Available BACKGROUND AND AIM: Mammalian spermatozoa are rich in polyunsaturated fatty acids and are very susceptible to attack by reactive oxygen species (ROS and membrane lipid peroxide ion. Normally a balance is maintained between the amount of ROS produced and that scavenged. Cellular damage arises when this equilibrium is disturbed. A shift in the levels of ROS towards pro-oxidants in semen and vaginal secretions can induce an oxidative stress on spermatozoa. The aim was to study lipid peroxidation and antioxidant enzymes such as catalase, glutathione peroxidase and superoxide dismutase (SOD and to correlate the same, with the ′water test′, in male infertility. SETTINGS: Experimental study. SUBJECTS AND METHODS: Ejaculates from a total of 83 infertile and fertile healthy individuals were obtained. Lipid peroxidation and antioxidant enzyme levels were studied and correlated with water test. RESULTS: The results indicate that (i the antioxidant enzyme catalase showed no significant changes in the various pathological samples, (ii antioxidant enzymes SOD and glutathione peroxidase correlate positively with asthenozoospermic samples and (iii the degree of lipid peroxidation also correlates positively with the poorly swollen sperm tails. The increase in SOD and glutathione peroxidase values, in the pathological cases represents an attempt made to overcome the reactive oxygen species. CONCLUSION: Water test could be used as a preliminary marker test for sperm tail damage by reactive oxygen species, since it correlates very well with lipid peroxidation and antioxidant enzymes.

  10. Enzyme Engineering for In Situ Immobilization.

    Science.gov (United States)

    Rehm, Fabian B H; Chen, Shuxiong; Rehm, Bernd H A

    2016-10-14

    Enzymes are used as biocatalysts in a vast range of industrial applications. Immobilization of enzymes to solid supports or their self-assembly into insoluble particles enhances their applicability by strongly improving properties such as stability in changing environments, re-usability and applicability in continuous biocatalytic processes. The possibility of co-immobilizing various functionally related enzymes involved in multistep synthesis, conversion or degradation reactions enables the design of multifunctional biocatalyst with enhanced performance compared to their soluble counterparts. This review provides a brief overview of up-to-date in vitro immobilization strategies while focusing on recent advances in enzyme engineering towards in situ self-assembly into insoluble particles. In situ self-assembly approaches include the bioengineering of bacteria to abundantly form enzymatically active inclusion bodies such as enzyme inclusions or enzyme-coated polyhydroxyalkanoate granules. These one-step production strategies for immobilized enzymes avoid prefabrication of the carrier as well as chemical cross-linking or attachment to a support material while the controlled oriented display strongly enhances the fraction of accessible catalytic sites and hence functional enzymes.

  11. [The rise of enzyme engineering in China].

    Science.gov (United States)

    Li, Gaoxiang

    2015-06-01

    Enzyme engineering is an important part of the modern biotechnology. Industrial biocatalysis is considered the third wave of biotechnology following pharmaceutical and agricultural waves. In 25 years, China has made a mighty advances in enzyme engineering research. This review focuses on enzyme genomics, enzyme proteomics, biosynthesis, microbial conversion and biosensors in the Chinese enzyme engineering symposiums and advances in enzyme preparation industry in China.

  12. Bioremediation of Industrial Waste Through Enzyme Producing Marine Microorganisms.

    Science.gov (United States)

    Sivaperumal, P; Kamala, K; Rajaram, R

    Bioremediation process using microorganisms is a kind of nature-friendly and cost-effective clean green technology. Recently, biodegradation of industrial wastes using enzymes from marine microorganisms has been reported worldwide. The prospectus research activity in remediation area would contribute toward the development of advanced bioprocess technology. To minimize industrial wastes, marine enzymes could constitute a novel alternative in terms of waste treatment. Nowadays, the evidence on the mechanisms of bioremediation-related enzymes from marine microorganisms has been extensively studied. This review also will provide information about enzymes from various marine microorganisms and their complexity in the biodegradation of comprehensive range of industrial wastes. © 2017 Elsevier Inc. All rights reserved.

  13. Accessory enzymes from Aspergillus involved in xylan and pectin degradation

    NARCIS (Netherlands)

    Vries, de R.P.

    1999-01-01

    The xylanolytic and pectinolytic enzyme systems from Aspergillus have been the subject of study for many years. Although the main chain cleaving enzymes and their encoding genes have been studied in detail, little information is available about most of the accessory

  14. Paper Microzone Plates as Analytical Tools for Studying Enzyme Stability: A Case Study on the Stabilization of Horseradish Peroxidase Using Trehalose and SU-8 Epoxy Novolac Resin.

    Science.gov (United States)

    Ganaja, Kirsten A; Chaplan, Cory A; Zhang, Jingyi; Martinez, Nathaniel W; Martinez, Andres W

    2017-05-16

    Paper microzone plates in combination with a noncontact liquid handling robot were demonstrated as tools for studying the stability of enzymes stored on paper. The effect of trehalose and SU-8 epoxy novolac resin (SU-8) on the stability of horseradish peroxidase (HRP) was studied in both a short-term experiment, where the activity of various concentrations of HRP dried on paper were measured after 1 h, and a long-term experiment, where the activity of a single concentration of HRP dried and stored on paper was monitored for 61 days. SU-8 was found to stabilize HRP up to 35 times more than trehalose in the short-term experiment for comparable concentrations of the two reagents, and a 1% SU-8 solution was found to stabilize HRP approximately 2 times more than a 34% trehalose solution in both short- and long-term experiments. The results suggest that SU-8 is a promising candidate for use as an enzyme-stabilizing reagent for paper-based diagnostic devices and that the short-term experiment could be used to quickly evaluate the capacity of various reagents for stabilizing enzymes to identify and characterize new enzyme-stabilizing reagents.

  15. Detoxifying enzyme studies on cotton leafhopper, Amrasca biguttula biguttula (Ishida, resistance to neonicotinoid insecticides in field populations in Karnataka, India

    Directory of Open Access Journals (Sweden)

    Halappa Banakar

    2016-12-01

    Full Text Available The cotton leafhopper (Amrasca biguttula biguttula Ishida is considered to be an alarming insect pest causing both quantitative and qualitative loss in cotton. In situ bioassay studies were done and the role of detoxifying enzymes in conferring resistance to neonicotinoid groups of insecticides in low (MUD, medium (DVG, high (HVR and very high (GLB pesticide usage areas of Karnataka were determined. Bioassay studies showed that imidacloprid, thiamethoxam, acetamiprid, thiacloprid and clothianidin registered varying levels of resistance for all the locations studied. The resistance ratio was high in imidacloprid (3.35, 8.57, 9.15 and 12.27 fold respectively and the lowest in dinoferuran (1.86, 5.13, 6.71 and 9.88 fold respectively. Furthermore, the enzyme activity ratio (glutathione-S-transferase was relatively greater, and corresponded to the higher LC50 values of neonicotinoids for very high, high, medium and low pesticide usage areas. Our study suggested that the higher activity of the detoxifying enzyme in the resistance population of cotton leafhopper apparently has a significant role in endowing resistance to neonicotinoid groups of insecticides. However, this study recommends using neonicotinoids in cotton growing areas with caution.

  16. Positron emitter labeled enzyme inhibitors

    International Nuclear Information System (INIS)

    Fowler, J.S.; MacGregor, R.R.; Wolf, A.P.; Langstrom, B.

    1990-01-01

    This invention involves a new strategy for imagining and mapping enzyme activity in the living human and animal body using positron emitter-labeled suicide enzyme inactivators or inhibitors which become covalently bound to the enzyme as a result of enzymatic catalysis. Two such suicide inactivators for monoamine oxidase have been labeled with carbon-11 and used to map the enzyme subtypes in the living human and animal body using PET. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography

  17. SH groups in the alpha-naphthyl acetate esterase in the thyroid of the guinea-pig. A histochemical study

    DEFF Research Database (Denmark)

    Kirkeby, S

    1976-01-01

    ] are added to the incubation media. Thus the inhibition is by far the greatest in group I cells, which also show the greatest activity after incubation in conventional media, when long fixation and storage times are used. In all cases the inhibiting effect was complete or almost completely reversed......The alpha-naphthyl acetate esterase in both group I and group II thyroid cells is shown to contain SH groups since there is a decline in activity in both cell groups when certain sulfhydryl reagents [DTNB; 5,5'-Dithiobis-(2-nitrobenzoic acid)-AgNO3-Mersalyl-PCMB (parachloro mercuribenzoate) + urea...... if cysteine was added to the incubation media in equivalent concentrations to the SH blocker. There were great differences among the sulfhydryl reagents used in their ability to bring about enzyme inhibition. The alkylating agents NEM (N-ethylmaleimide) and iodoacetamide had no or little effect while PCMB...

  18. Structural analysis of enzymes used for bioindustry and bioremediation.

    Science.gov (United States)

    Tanokura, Masaru; Miyakawa, Takuya; Guan, Lijun; Hou, Feng

    2015-01-01

    Microbial enzymes have been widely applied in the large-scale, bioindustrial manufacture of food products and pharmaceuticals due to their high substrate specificity and stereoselectivity, and their effectiveness under mild conditions with low environmental burden. At the same time, bioremedial techniques using microbial enzymes have been developed to solve the problem of industrial waste, particularly with respect to persistent chemicals and toxic substances. And finally, structural studies of these enzymes have revealed the mechanistic basis of enzymatic reactions, including the stereoselectivity and binding specificity of substrates and cofactors. The obtained structural insights are useful not only to deepen our understanding of enzymes with potential bioindustrial and/or bioremedial application, but also for the functional improvement of enzymes through rational protein engineering. This review shows the structural bases for various types of enzymatic reactions, including the substrate specificity accompanying cofactor-controlled and kinetic mechanisms.

  19. Compounds from silicones alter enzyme activity in curing barnacle glue and model enzymes.

    Science.gov (United States)

    Rittschof, Daniel; Orihuela, Beatriz; Harder, Tilmann; Stafslien, Shane; Chisholm, Bret; Dickinson, Gary H

    2011-02-17

    Attachment strength of fouling organisms on silicone coatings is low. We hypothesized that low attachment strength on silicones is, in part, due to the interaction of surface available components with natural glues. Components could alter curing of glues through bulk changes or specifically through altered enzyme activity. GC-MS analysis of silicone coatings showed surface-available siloxanes when the coatings were gently rubbed with a cotton swab for 15 seconds or given a 30 second rinse with methanol. Mixtures of compounds were found on 2 commercial and 8 model silicone coatings. The hypothesis that silicone components alter glue curing enzymes was tested with curing barnacle glue and with commercial enzymes. In our model, barnacle glue curing involves trypsin-like serine protease(s), which activate enzymes and structural proteins, and a transglutaminase which cross-links glue proteins. Transglutaminase activity was significantly altered upon exposure of curing glue from individual barnacles to silicone eluates. Activity of purified trypsin and, to a greater extent, transglutaminase was significantly altered by relevant concentrations of silicone polymer constituents. Surface-associated silicone compounds can disrupt glue curing and alter enzyme properties. Altered curing of natural glues has potential in fouling management.

  20. Prediction of Wild-type Enzyme Characteristics

    DEFF Research Database (Denmark)

    Geertz-Hansen, Henrik Marcus

    of biotechnology, including enzyme discovery and characterization. This work presents two articles on sequence-based discovery and functional annotation of enzymes in environmental samples, and two articles on analysis and prediction of enzyme thermostability and cofactor requirements. The first article presents...... a sequence-based approach to discovery of proteolytic enzymes in metagenomes obtained from the Polar oceans. We show that microorganisms living in these extreme environments of constant low temperature harbour genes encoding novel proteolytic enzymes with potential industrial relevance. The second article...... presents a web server for the processing and annotation of functional metagenomics sequencing data, tailored to meet the requirements of non-bioinformaticians. The third article presents analyses of the molecular determinants of enzyme thermostability, and a feature-based prediction method of the melting...

  1. Molecular Modeling of Enzyme Dynamics Towards Understanding Solvent Effects

    DEFF Research Database (Denmark)

    Wedberg, Nils Hejle Rasmus Ingemar

    This thesis describes the development of a molecular simulation methodology to study properties of enzymes in non-aqueous media at fixed thermodynamic water activities. The methodology is applied in a molecular dynamics study of the industrially important enzyme Candida antarctica lipase B (CALB...... of enzyme kinetics in non-aqueous media, it has been a fruitful approach to fix the enzyme hydration level by controlling the water activity of the medium. In this work, a protocol is therefore developed for determining the water activity in non-aqueous protein simulations. The method relies on determining...... integration, while for small systems, it seems to be even better. The method is applied to compute the excess Gibbs energy of the mixtures of water and organic solvents used in the simulations of CALB. This allows to determine the water activity of the simulated systems and thus to compare protein properties...

  2. In Silico Phylogenetic Analysis and Molecular Modelling Study of 2-Haloalkanoic Acid Dehalogenase Enzymes from Bacterial and Fungal Origin

    Directory of Open Access Journals (Sweden)

    Raghunath Satpathy

    2016-01-01

    Full Text Available 2-Haloalkanoic acid dehalogenase enzymes have broad range of applications, starting from bioremediation to chemical synthesis of useful compounds that are widely distributed in fungi and bacteria. In the present study, a total of 81 full-length protein sequences of 2-haloalkanoic acid dehalogenase from bacteria and fungi were retrieved from NCBI database. Sequence analysis such as multiple sequence alignment (MSA, conserved motif identification, computation of amino acid composition, and phylogenetic tree construction were performed on these primary sequences. From MSA analysis, it was observed that the sequences share conserved lysine (K and aspartate (D residues in them. Also, phylogenetic tree indicated a subcluster comprised of both fungal and bacterial species. Due to nonavailability of experimental 3D structure for fungal 2-haloalkanoic acid dehalogenase in the PDB, molecular modelling study was performed for both fungal and bacterial sources of enzymes present in the subcluster. Further structural analysis revealed a common evolutionary topology shared between both fungal and bacterial enzymes. Studies on the buried amino acids showed highly conserved Leu and Ser in the core, despite variation in their amino acid percentage. Additionally, a surface exposed tryptophan was conserved in all of these selected models.

  3. Therapeutic Enzymes: Applications and Approaches to Pharmacological Improvement.

    Science.gov (United States)

    Yari, Maryam; Ghoshoon, Mohammad B; Vakili, Bahareh; Ghasemi, Younes

    2017-01-01

    Among therapeutic proteins, enzymes represent small and of course profitable market. They can be used to treat important, rare, and deadly diseases. Enzyme therapy is the only available treatment for certain disorders. Here, pharmaceutical enzymes are reviewed. They are categorized in four main groups, enzymes in replacement therapy, enzymes in cancer treatment, enzymes for fibrinolysis, and finally enzymes that are used topically for various treatments. Furthermore, enzyme gene therapy and future perspective of therapeutic enzymes are mentioned in brief. There are many important approved enzymes in pharmaceutical market. Several approaches such as point mutation, fusion protein designing, glycoengineering, and PEGylation were used to achieve improved enzymes. Although sometimes enzymes were engineered to facilitate production and purification process, appropriate delivery to target sites, extending half-life, and reducing immunogenicity are among the main goals of engineering approaches. Overall, enzymes play a critical role in treatment of common and rare diseases. Evaluation of new enzymes as well as improvement of approved enzymes are of the most important challenges in biotechnology. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  4. Muscular sufficiency, serum protein, enzymes and bioenergetic studies in chronic malnutrition. [31-phosphorus magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, R K; Mittal, R D; Agarwal, K N; Agarwal, D K [Banaras Hindu Univ., Varanasi (India)

    1994-03-01

    Muscle sufficiency was significantly lower in 1336 children with chronic malnutrition of moderate to severe degree. 18 children with a chronic moderate degree of malnutrition and 8 well-nourished age-matched controls were selected for biochemical and 31-phosphorus magnetic resonance spectroscopy (31-P MRS) studies. The results shows that: (a) serum total protein, albumin, iron, calcium and inorganic phosphate were similar in both groups; (b) serum enzyme levels were significantly increased in the malnuourished group; (c) 31-P MRS showed significantly higher means for total ATP, [beta]-ATP, [alpha]-ATP and inorganic phosphate for the malnourished compared to the control group. In chronic malnutrition, proteins are maintained by degradation in muscle resulting in release of amino acids and enzymes. 31-P MRS studies showing increases in total ATP, [beta]-ATP and inorganic phosphate and a decrease in phosphocreatine suggest that ATP is maintained at the cost of phosphocreatine. 22 refs., 4 tabs. 1 fig.

  5. Molecular docking studies of 3-bromopyruvate and its derivatives to metabolic regulatory enzymes: Implication in designing of novel anticancer therapeutic strategies.

    Science.gov (United States)

    Yadav, Saveg; Pandey, Shrish Kumar; Singh, Vinay Kumar; Goel, Yugal; Kumar, Ajay; Singh, Sukh Mahendra

    2017-01-01

    Altered metabolism is an emerging hallmark of cancer, as malignant cells display a mammoth up-regulation of enzymes responsible for steering their bioenergetic and biosynthetic machinery. Thus, the recent anticancer therapeutic strategies focus on the targeting of metabolic enzymes, which has led to the identification of specific metabolic inhibitors. One of such inhibitors is 3-bromopyruvate (3-BP), with broad spectrum of anticancer activity due to its ability to inhibit multiple metabolic enzymes. However, the molecular characterization of its binding to the wide spectrum of target enzymes remains largely elusive. Therefore, in the present study we undertook in silico investigations to decipher the molecular nature of the docking of 3-BP with key target enzymes of glycolysis and TCA cycle by PatchDock and YASARA docking tools. Additionally, derivatives of 3-BP, dibromopyruvate (DBPA) and propionic acid (PA), with reported biological activity, were also investigated for docking to important target metabolic enzymes of 3-BP, in order to predict their therapeutic efficacy versus that of 3-BP. A comparison of the docking scores with respect to 3-BP indicated that both of these derivatives display a better binding strength to metabolic enzymes. Further, analysis of the drug likeness of 3-BP, DBPA and PA by Lipinski filter, admetSAR and FAF Drug3 indicated that all of these agents showed desirable drug-like criteria. The outcome of this investigation sheds light on the molecular characteristics of the binding of 3-BP and its derivatives with metabolic enzymes and thus may significantly contribute in designing and optimizing therapeutic strategies against cancer by using these agents.

  6. Molecular docking studies of 3-bromopyruvate and its derivatives to metabolic regulatory enzymes: Implication in designing of novel anticancer therapeutic strategies.

    Directory of Open Access Journals (Sweden)

    Saveg Yadav

    Full Text Available Altered metabolism is an emerging hallmark of cancer, as malignant cells display a mammoth up-regulation of enzymes responsible for steering their bioenergetic and biosynthetic machinery. Thus, the recent anticancer therapeutic strategies focus on the targeting of metabolic enzymes, which has led to the identification of specific metabolic inhibitors. One of such inhibitors is 3-bromopyruvate (3-BP, with broad spectrum of anticancer activity due to its ability to inhibit multiple metabolic enzymes. However, the molecular characterization of its binding to the wide spectrum of target enzymes remains largely elusive. Therefore, in the present study we undertook in silico investigations to decipher the molecular nature of the docking of 3-BP with key target enzymes of glycolysis and TCA cycle by PatchDock and YASARA docking tools. Additionally, derivatives of 3-BP, dibromopyruvate (DBPA and propionic acid (PA, with reported biological activity, were also investigated for docking to important target metabolic enzymes of 3-BP, in order to predict their therapeutic efficacy versus that of 3-BP. A comparison of the docking scores with respect to 3-BP indicated that both of these derivatives display a better binding strength to metabolic enzymes. Further, analysis of the drug likeness of 3-BP, DBPA and PA by Lipinski filter, admetSAR and FAF Drug3 indicated that all of these agents showed desirable drug-like criteria. The outcome of this investigation sheds light on the molecular characteristics of the binding of 3-BP and its derivatives with metabolic enzymes and thus may significantly contribute in designing and optimizing therapeutic strategies against cancer by using these agents.

  7. Thermophilic archaeal enzymes and applications in biocatalysis.

    Science.gov (United States)

    Littlechild, Jennifer A

    2011-01-01

    Thermophilic enzymes have advantages for their use in commercial applications and particularly for the production of chiral compounds to produce optically pure pharmaceuticals. They can be used as biocatalysts in the application of 'green chemistry'. The thermophilic archaea contain enzymes that have already been used in commercial applications such as the L-aminoacylase from Thermococcus litoralis for the resolution of amino acids and amino acid analogues. This enzyme differs from bacterial L-aminoacylases and has similarities to carboxypeptidases from other archaeal species. An amidase/γ-lactamase from Sulfolobus solfataricus has been used for the production of optically pure γ-lactam, the building block for antiviral carbocyclic nucleotides. This enzyme has similarities to the bacterial signature amidase family. An alcohol dehydrogenase from Aeropyrum pernix has been used for the production of optically pure alcohols and is related to the zinc-containing eukaryotic alcohol dehydrogenases. A transaminase and a dehalogenase from Sulfolobus species have also been studied. The archaeal transaminase is found in a pathway for serine synthesis which is found only in eukaryotes and not in bacteria. It can be used for the asymmetric synthesis of homochiral amines of high enantioselective purity. The L-2-haloacid dehalogenase has applications both in biocatalysis and in bioremediation. All of these enzymes have increased thermostability over their mesophilic counterparts.

  8. Flavonoids as modulators of metabolic enzymes and drug transporters.

    Science.gov (United States)

    Miron, Anca; Aprotosoaie, Ana Clara; Trifan, Adriana; Xiao, Jianbo

    2017-06-01

    Flavonoids, natural compounds found in plants and in plant-derived foods and beverages, have been extensively studied with regard to their capacity to modulate metabolic enzymes and drug transporters. In vitro, flavonoids predominantly inhibit the major phase I drug-metabolizing enzyme CYP450 3A4 and the enzymes responsible for the bioactivation of procarcinogens (CYP1 enzymes) and upregulate the enzymes involved in carcinogen detoxification (UDP-glucuronosyltransferases, glutathione S-transferases (GSTs)). Flavonoids have been reported to inhibit ATP-binding cassette (ABC) transporters (multidrug resistance (MDR)-associated proteins, breast cancer-resistance protein) that contribute to the development of MDR. P-glycoprotein, an ABC transporter that limits drug bioavailability and also induces MDR, was differently modulated by flavonoids. Flavonoids and their phase II metabolites (sulfates, glucuronides) inhibit organic anion transporters involved in the tubular uptake of nephrotoxic compounds. In vivo studies have partially confirmed in vitro findings, suggesting that the mechanisms underlying the modulatory effects of flavonoids are complex and difficult to predict in vivo. Data summarized in this review strongly support the view that flavonoids are promising candidates for the enhancement of oral drug bioavailability, chemoprevention, and reversal of MDR. © 2017 New York Academy of Sciences.

  9. 'In vitro' studies on the interaction of rickettsia and macrophages. I. Effect of ultraviolet light on 'Coxiella burnetii' inactivation and macrophage enzymes: uv-inactivated 'C. burnetii'/macrophage enzymes. Interim report

    Energy Technology Data Exchange (ETDEWEB)

    Little, J.S.; Kishimoto, R.A.; Canonico, P.G.

    1979-09-04

    The inactivation of Coxiella burnetii in suspension or in cultures of guinea pig peritoneal macrophages by ultraviolet (UV) light was studied. The effect of UV treatment on the activity of macrophage organelle marker enzymes and their subsequent equilibration in linear sucrose gradients was also determined. It was shown that UV treatment of 600 microwatts/sq cm for 15 sec at a distance of 10 cm inactivated C. burnetii, either in suspension (10 to the 8th power organisms/ML) or within guinea pig peritoneal macrophages. Similar UV treatment had little effect on the activity or equilibration of macrophage organelle marker enzymes in linear sucrose gradients. However, longer exposure caused considerable inactivatioin of these enzymes.

  10. Production of β-Glucanase Enzyme from Penicillium oxalicum and ...

    African Journals Online (AJOL)

    Mr. J.H. Doughari

    2011-08-24

    Aug 24, 2011 ... inhibited β-glucanase activity. β-Glucanase can be produced from some ... glucanases as industrial enzymes, this study was carried .... has an immense economic advantage as the enzyme ... cost with subsequent low price of the final products to ... fermentation industries whose manufacturing conditions.

  11. Halophiles and their enzymes: Negativity put to good use

    Science.gov (United States)

    DasSarma, Shiladitya; DasSarma, Priya

    2015-01-01

    Halophilic microorganisms possess stable enzymes that function in very high salinity, an extreme condition that leads to denaturation, aggregation, and precipitation of most other proteins. Genomic and structural analyses have established that the enzymes of halophilic Archaea and many halophilic Bacteria are negatively charged due to an excess of acidic over basic residues, and altered hydrophobicity, which enhance solubility and promote function in low water activity conditions. Here, we provide an update on recent bioinformatic analysis of predicted halophilic proteomes as well as experimental molecular studies on individual halophilic enzymes. On-going efforts on discovery and utilization of halophiles and their enzymes for biotechnology, including biofuel applications are also considered. PMID:26066288

  12. Halophiles and their enzymes: negativity put to good use.

    Science.gov (United States)

    DasSarma, Shiladitya; DasSarma, Priya

    2015-06-01

    Halophilic microorganisms possess stable enzymes that function in very high salinity, an extreme condition that leads to denaturation, aggregation, and precipitation of most other proteins. Genomic and structural analyses have established that the enzymes of halophilic Archaea and many halophilic Bacteria are negatively charged due to an excess of acidic over basic residues, and altered hydrophobicity, which enhance solubility and promote function in low water activity conditions. Here, we provide an update on recent bioinformatic analysis of predicted halophilic proteomes as well as experimental molecular studies on individual halophilic enzymes. Recent efforts on discovery and utilization of halophiles and their enzymes for biotechnology, including biofuel applications are also considered. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Comparative gene expression of intestinal metabolizing enzymes.

    Science.gov (United States)

    Shin, Ho-Chul; Kim, Hye-Ryoung; Cho, Hee-Jung; Yi, Hee; Cho, Soo-Min; Lee, Dong-Goo; Abd El-Aty, A M; Kim, Jin-Suk; Sun, Duxin; Amidon, Gordon L

    2009-11-01

    The purpose of this study was to compare the expression profiles of drug-metabolizing enzymes in the intestine of mouse, rat and human. Total RNA was isolated from the duodenum and the mRNA expression was measured using Affymetrix GeneChip oligonucleotide arrays. Detected genes from the intestine of mouse, rat and human were ca. 60% of 22690 sequences, 40% of 8739 and 47% of 12559, respectively. Total genes of metabolizing enzymes subjected in this study were 95, 33 and 68 genes in mouse, rat and human, respectively. Of phase I enzymes, the mouse exhibited abundant gene expressions for Cyp3a25, Cyp4v3, Cyp2d26, followed by Cyp2b20, Cyp2c65 and Cyp4f14, whereas, the rat showed higher expression profiles of Cyp3a9, Cyp2b19, Cyp4f1, Cyp17a1, Cyp2d18, Cyp27a1 and Cyp4f6. However, the highly expressed P450 enzymes were CYP3A4, CYP3A5, CYP4F3, CYP2C18, CYP2C9, CYP2D6, CYP3A7, CYP11B1 and CYP2B6 in the human. For phase II enzymes, glucuronosyltransferase Ugt1a6, glutathione S-transferases Gstp1, Gstm3 and Gsta2, sulfotransferase Sult1b1 and acyltransferase Dgat1 were highly expressed in the mouse. The rat revealed predominant expression of glucuronosyltransferases Ugt1a1 and Ugt1a7, sulfotransferase Sult1b1, acetyltransferase Dlat and acyltransferase Dgat1. On the other hand, in human, glucuronosyltransferases UGT2B15 and UGT2B17, glutathione S-transferases MGST3, GSTP1, GSTA2 and GSTM4, sulfotransferases ST1A3 and SULT1A2, acetyltransferases SAT1 and CRAT, and acyltransferase AGPAT2 were dominantly detected. Therefore, current data indicated substantial interspecies differences in the pattern of intestinal gene expression both for P450 enzymes and phase II drug-metabolizing enzymes. This genomic database is expected to improve our understanding of interspecies variations in estimating intestinal prehepatic clearance of oral drugs.

  14. Modeling the reactions catalyzed by coenzyme B12-dependent enzymes.

    Science.gov (United States)

    Sandala, Gregory M; Smith, David M; Radom, Leo

    2010-05-18

    Enzymes accelerate chemical reactions with an exceptional selectivity that makes life itself possible. Understanding the factors responsible for this efficient catalysis is of utmost importance in our quest to harness the tremendous power of enzymes. Computational chemistry has emerged as an important adjunct to experimental chemistry and biochemistry in this regard, because it provides detailed insights into the relationship between structure and function in a systematic and straightforward manner. In this Account, we highlight our recent high-level theoretical investigations toward this end in studying the radical-based reactions catalyzed by enzymes dependent on coenzyme B(12) (or adenosylcobalamin, AdoCbl). In addition to their fundamental position in biology, the AdoCbl-dependent enzymes represent a valuable framework within which to understand Nature's method of efficiently handling high-energy species to execute very specific reactions. The AdoCbl-mediated reactions are characterized by the interchange of a hydrogen atom and a functional group on adjacent carbon atoms. Our calculations are consistent with the conclusion that the main role of AdoCbl is to provide a source of radicals, thus moving the 1,2-rearrangements onto the radical potential energy surface. Our studies also show that the radical rearrangement step is facilitated by partial proton transfer involving the substrate. Specifically, we observe that the energy requirements for radical rearrangement are reduced dramatically with appropriate partial protonation or partial deprotonation or sometimes (synergistically) both. Such interactions are particularly relevant to enzyme catalysis, because it is likely that the local amino acid environment in the active site of an enzyme can function in this capacity through hydrogen bonding. Finally, our calculations indicate that the intervention of a very stable radical along the reaction pathway may inactivate the enzyme, demonstrating that sustained

  15. Bio-functionalization of electro-synthesized polypyrrole surface by heme enzyme using a mixture of Nafion and glutaraldehyde as synergetic immobilization matrix: Conformational characterization and electrocatalytic studies

    International Nuclear Information System (INIS)

    ElKaoutit, Mohammed; Naranjo-Rodriguez, Ignacio; Dominguez, Manuel; Hidalgo-Hidalgo-de-Cisneros, Jose Luis

    2011-01-01

    Use of a mixture of Nafion and glutaraldehyde as new immobilization matrix was described. The percentage of Nafion was optimized to prevent denaturation of horseradish peroxidase enzyme after its crosslinkage with glutaraldehyde on electro-synthesized polypyrrole surface. Topographic study by Atomic Force Microscopy (AFM) shows that the enzyme seems to have been introduced inside the ionic cluster of Nafion. The characterization of the resulting bio-interfaces by UV-vis and FT-IR shows that the intra-crosslinkage phenomena caused by the use of glutaraldehyde can be eliminated by the optimization of the concentration of Nafion additive. The secondary structure contents of native and immobilized enzyme were analyzed by a Gaussian curve fitting of the respective FT-IR spectra in the amide I region. Immobilized enzyme presented notable increasing percentages of globular and short helical structure compared with native enzyme. This indicates that immobilized enzyme was folded which is in accordance with AFM studies and supports the enzyme entrance inside ionic clutter of Nafion. Thanks to synergic effects of the polypyrrole conducting polymer and the perfluorosulfonic acid polymer Nafion, HRP enzyme was immobilized in its 'native' state, the resulting biosensor was able to sense peroxide without any chemical mediator and can be categorized as third generation.

  16. Bio-functionalization of electro-synthesized polypyrrole surface by heme enzyme using a mixture of Nafion and glutaraldehyde as synergetic immobilization matrix: Conformational characterization and electrocatalytic studies

    Energy Technology Data Exchange (ETDEWEB)

    ElKaoutit, Mohammed, E-mail: elkaoutit@uca.es [Departamento de Quimica Analitica, Facultad de Ciencias, Universidad de Cadiz, 11510 Puerto Real, Cadiz (Spain); Naranjo-Rodriguez, Ignacio [Departamento de Quimica Analitica, Facultad de Ciencias, Universidad de Cadiz, 11510 Puerto Real, Cadiz (Spain); Dominguez, Manuel [Departamento de Fisica de la Materia Condensada, Facultad de Ciencias, Universidad de Cadiz, 11510 Puerto Real, Cadiz (Spain); Hidalgo-Hidalgo-de-Cisneros, Jose Luis [Departamento de Quimica Analitica, Facultad de Ciencias, Universidad de Cadiz, 11510 Puerto Real, Cadiz (Spain)

    2011-10-01

    Use of a mixture of Nafion and glutaraldehyde as new immobilization matrix was described. The percentage of Nafion was optimized to prevent denaturation of horseradish peroxidase enzyme after its crosslinkage with glutaraldehyde on electro-synthesized polypyrrole surface. Topographic study by Atomic Force Microscopy (AFM) shows that the enzyme seems to have been introduced inside the ionic cluster of Nafion. The characterization of the resulting bio-interfaces by UV-vis and FT-IR shows that the intra-crosslinkage phenomena caused by the use of glutaraldehyde can be eliminated by the optimization of the concentration of Nafion additive. The secondary structure contents of native and immobilized enzyme were analyzed by a Gaussian curve fitting of the respective FT-IR spectra in the amide I region. Immobilized enzyme presented notable increasing percentages of globular and short helical structure compared with native enzyme. This indicates that immobilized enzyme was folded which is in accordance with AFM studies and supports the enzyme entrance inside ionic clutter of Nafion. Thanks to synergic effects of the polypyrrole conducting polymer and the perfluorosulfonic acid polymer Nafion, HRP enzyme was immobilized in its 'native' state, the resulting biosensor was able to sense peroxide without any chemical mediator and can be categorized as third generation.

  17. A preliminary neutron diffraction study of rasburicase, a recombinant urate oxidase enzyme, complexed with 8-azaxanthin

    Energy Technology Data Exchange (ETDEWEB)

    Budayova-Spano, Monika, E-mail: spano@embl-grenoble.fr [European Molecular Biology Laboratory Grenoble Outstation, 6 Rue Jules Horowitz, 38042 Grenoble (France); Institut Laue-Langevin, 6 Rue Jules Horowitz, BP 156, 38042 Grenoble (France); Bonneté, Françoise; Ferté, Natalie [Centre de Recherche en Matière Condensée et Nanosciences, Campus de Luminy, Case 913, 13288 Marseille (France); El Hajji, Mohamed [Sanofi-Aventis, 371 Rue du Professeur Blayac, 34184 Montpellier (France); Meilleur, Flora [Institut Laue-Langevin, 6 Rue Jules Horowitz, BP 156, 38042 Grenoble (France); Blakeley, Matthew Paul [European Molecular Biology Laboratory Grenoble Outstation, 6 Rue Jules Horowitz, 38042 Grenoble (France); Castro, Bertrand [Sanofi-Aventis, 371 Rue du Professeur Blayac, 34184 Montpellier (France); European Molecular Biology Laboratory Grenoble Outstation, 6 Rue Jules Horowitz, 38042 Grenoble (France)

    2006-03-01

    Neutron diffraction data of hydrogenated recombinant urate oxidase enzyme (Rasburicase), complexed with a purine-type inhibitor 8-azaxanthin, was collected to 2.1 Å resolution from a crystal grown in D{sub 2}O by careful control and optimization of crystallization conditions via knowledge of the phase diagram. Deuterium atoms were clearly seen in the neutron-scattering density map. Crystallization and preliminary neutron diffraction measurements of rasburicase, a recombinant urate oxidase enzyme expressed by a genetically modified Saccharomyces cerevisiae strain, complexed with a purine-type inhibitor (8-azaxanthin) are reported. Neutron Laue diffraction data were collected to 2.1 Å resolution using the LADI instrument from a crystal (grown in D{sub 2}O) with volume 1.8 mm{sup 3}. The aim of this neutron diffraction study is to determine the protonation states of the inhibitor and residues within the active site. This will lead to improved comprehension of the enzymatic mechanism of this important enzyme, which is used as a protein drug to reduce toxic uric acid accumulation during chemotherapy. This paper illustrates the high quality of the neutron diffraction data collected, which are suitable for high-resolution structural analysis. In comparison with other neutron protein crystallography studies to date in which a hydrogenated protein has been used, the volume of the crystal was relatively small and yet the data still extend to high resolution. Furthermore, urate oxidase has one of the largest primitive unit-cell volumes (space group I222, unit-cell parameters a = 80, b = 96, c = 106 Å) and molecular weights (135 kDa for the homotetramer) so far successfully studied with neutrons.

  18. Characterization of nonlymphoid cells in rat spleen, with special reference to strongly Ia-positive branched cells in T-cell areas

    International Nuclear Information System (INIS)

    Dijkstra, C.D.

    1982-01-01

    By use of a monoclonal antibody against Ia antigen in an immunoperoxidase method, strongly Ia-positive branched cells are found in the T-cell areas of the splenic white pulp of the rat. In order to further characterize these cells, enzyme histochemical characteristics, phagocytic capacity, and irradiation sensitivity have been studied. Evidence is presented that these strongly Ia-positive branched cells represent interdigitating cells. The influence of whole-body irradiation on interdigitating cells is discussed. Comparison with data from the literature on the in vitro dendritic cell isolated from spleen cell suspensions reveals many similarities between the described interdigitating cell in vivo and the dendritic cell in vitro

  19. Modification of enzymes by use of high-pressure homogenization.

    Science.gov (United States)

    Dos Santos Aguilar, Jessika Gonçalves; Cristianini, Marcelo; Sato, Helia Harumi

    2018-07-01

    High-pressure is an emerging and relatively new technology that can modify various molecules. High-pressure homogenization (HPH) has been used in several studies on protein modification, especially in enzymes used or found in food, from animal, plant or microbial resources. According to the literature, the enzymatic activity can be modulated under pressure causing inactivation, stabilization or activation of the enzymes, which, depending on the point of view could be very useful. Homogenization can generate changes in the structure of the enzyme modifying various chemical bonds (mainly weak bonds) causing different denaturation levels and, consequently, affecting the catalytic activity. This review aims to describe the various alterations due to HPH treatment in enzymes, to show the influence of high-pressure on proteins and to report the HPH effects on the enzymatic activity of different enzymes employed in the food industry and research. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Adsorption of Trametes versicolor laccase to soil iron and aluminum minerals: enzyme activity, kinetics and stability studies.

    Science.gov (United States)

    Wu, Yue; Jiang, Ying; Jiao, Jiaguo; Liu, Manqiang; Hu, Feng; Griffiths, Bryan S; Li, Huixin

    2014-02-01

    Laccases play an important role in the degradation of soil phenol or phenol-like substance and can be potentially used in soil remediation through immobilization. Iron and aluminum minerals can adsorb extracellular enzymes in soil environment. In the present study, we investigated the adsorptive interaction of laccase, from the white-rot fungus Trametes versicolor, with soil iron and aluminum minerals and characterized the properties of the enzyme after adsorption to minerals. Results showed that both soil iron and aluminum minerals adsorbed great amount of laccase, independent of the mineral specific surface areas. Adsorbed laccases retained 26-64% of the activity of the free enzyme. Compared to the free laccase, all adsorbed laccases showed higher Km values and lower Vmax values, indicating a reduced enzyme-substrate affinity and a lower rate of substrate conversion in reactions catalyzed by the adsorbed laccase. Adsorbed laccases exhibited increased catalytic activities compared to the free laccase at low pH, implying the suitable application of iron and aluminum mineral-adsorbed T. versicolor laccase in soil bioremediation, especially in acid soils. In terms of the thermal profiles, adsorbed laccases showed decreased thermal stability and higher temperature sensitivity relative to the free laccase. Moreover, adsorption improved the resistance of laccase to proteolysis and extended the lifespan of laccase. Our results implied that adsorbed T. versicolor laccase on soil iron and aluminum minerals had promising potential in soil remediation. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  1. The role of enzymes in fungus-growing ant evolution

    DEFF Research Database (Denmark)

    de Fine Licht, Henrik Hjarvard

    behaviour. Here we report the first large-scale comparative study on fungus garden enzyme profiles and show that various interesting changes can be documented. A more detailed analysis of laccase expression, an enzyme that is believed to oxidize phenols in defensive secondary plant compounds such as tannins...

  2. Effect of diffusion on enzyme activity in a microreactor

    NARCIS (Netherlands)

    Swarts, J.W.; Kolfschoten, R.C.; Jansen, M.C.A.A.; Janssen, A.E.M.; Boom, R.M.

    2010-01-01

    To establish general rules for setting up an enzyme microreactor system, we studied the effect of diffusion on enzyme activity in a microreactor. As a model system we used the hydrolysis of ortho-nitrophenyl-ß-d-galactopyranoside by ß-galactosidase from Kluyveromyces lactis. We found that the

  3. Photoperiodism and Enzyme Activity

    Science.gov (United States)

    Queiroz, Orlando; Morel, Claudine

    1974-01-01

    Metabolic readjustments after a change from long days to short days appear, in Kalanchoe blossfeldiana, to be achieved through the operation of two main mechanisms: variation in enzyme capacity, and circadian rhythmicity. After a lag time, capacity in phosphoenolpyruvate carboxylase and capacity in aspartate aminotransferase increase exponentially and appear to be allometrically linked during 50 to 60 short days; then a sudden fall takes place in the activity of the former. Malic enzyme and alanine aminotransferase behave differently. Thus, the operation of the two sections of the pathway (before and after the malate step) give rise to a continuously changing functional compartmentation in the pathway. Circadian rhythmicity, on the other hand, produces time compartmentation through phase shifts and variation in amplitude, independently for each enzyme. These characteristics suggest that the operation of a so-called biological clock would be involved. We propose the hypothesis that feedback regulation would be more accurate and efficient when applied to an already oscillating, clock-controlled enzyme system. PMID:16658749

  4. Descriptive and predictive assessment of enzyme activity and enzyme related processes in biorefinery using IR spectroscopy and chemometrics

    DEFF Research Database (Denmark)

    Baum, Andreas

    the understanding of the structural properties of the extracted pectin. Secondly, enzyme kinetics of biomass converting enzymes was examined in terms of measuring enzyme activity by spectral evolution profiling utilizing FTIR. Chemometric multiway methods were used to analyze the tensor datasets enabling the second......-order calibration advantage (reference Theory of Analytical chemistry). As PAPER 3 illustrates the method is universally applicable without the need of any external standards and was exemplified by performing quantitative enzyme activity determinations for glucose oxidase, pectin lyase and a cellolytic enzyme blend...... (Celluclast 1.5L). In PAPER 4, the concept is extended to quantify enzyme activity of two simultaneously acting enzymes, namely pectin lyase and pectin methyl esterase. By doing so the multiway methods PARAFAC, TUCKER3 and NPLS were compared and evaluated towards accuracy and precision....

  5. Effect of irradiation on lysosomal enzyme activation in cultured macrophages

    International Nuclear Information System (INIS)

    Clarke, C.; Wills, E.D.

    1980-01-01

    The effect of γrays on lysosomal enzyme activity of normal and immune macrophages of DBA/2 mice cultured in vitro has been studied. A dose of 500 rad did not significantly affect lysosomal enzyme activity 3 hours after irradiation but caused the activity to increase to 1.4 times the control value 22.5 hours after irradiation. 22.5 hours after a dose of 3000 rad the enzyme activity increased to 2.5 times the control. Lysosomal enzyme activity of the macrophages was also markedly increased by immunization of the mice with D lymphoma cells, before culture in vitro, but irradiation of these cells with a dose of 500 rad caused a further increase in lysosomal enzyme activity. The results indicate that immunization and irradiation both cause stimulation of lysosomal enzyme activity in macrophages but that the mechanisms of activation are unlikely to be identical. (author)

  6. Engineering of GlcNAc-1-Phosphotransferase for Production of Highly Phosphorylated Lysosomal Enzymes for Enzyme Replacement Therapy.

    Science.gov (United States)

    Liu, Lin; Lee, Wang-Sik; Doray, Balraj; Kornfeld, Stuart

    2017-06-16

    Several lysosomal enzymes currently used for enzyme replacement therapy in patients with lysosomal storage diseases contain very low levels of mannose 6-phosphate, limiting their uptake via mannose 6-phosphate receptors on the surface of the deficient cells. These enzymes are produced at high levels by mammalian cells and depend on endogenous GlcNAc-1-phosphotransferase α/β precursor to phosphorylate the mannose residues on their glycan chains. We show that co-expression of an engineered truncated GlcNAc-1-phosphotransferase α/β precursor and the lysosomal enzyme of interest in the producing cells resulted in markedly increased phosphorylation and cellular uptake of the secreted lysosomal enzyme. This method also results in the production of highly phosphorylated acid β-glucocerebrosidase, a lysosomal enzyme that normally has just trace amounts of this modification.

  7. Evaluation of pressure tuning of enzymes

    DEFF Research Database (Denmark)

    Naghshineh, Mahsa

    and high energy consumption. Therefore, searching for an environmentally friendly method of pectin extraction is a task for science and industry. Employment of hydrolytic enzymes may represent a green approach to obtain intact pectin polymer. However, the low stability/activity of enzymes, and low polymer...... yield of enzymatic extraction limits the application of enzyme in pectin production. There is evidence that emerging technology of high hydrostatic pressure processing can result in stabilization and activation of some enzymes. Therefore, the use of high hydrostatic pressure in combination with enzyme...... (cellulase/xylanase: 50/0, 50/25, 50/50, 25/50, and 0/50 U/g lime peel) at ambient pressure, 100 and 200 MPa were used to extract pectin from dried lime peel waste. It was found that pressure level, type and concentration of enzyme significantly influenced pectin yield and degree of esterification (DE...

  8. Enzyme activity measurement via spectral evolution profiling and PARAFAC

    DEFF Research Database (Denmark)

    Baum, Andreas; Meyer, Anne S.; Garcia, Javier Lopez

    2013-01-01

    The recent advances in multi-way analysis provide new solutions to traditional enzyme activity assessment. In the present study enzyme activity has been determined by monitoring spectral changes of substrates and products in real time. The method relies on measurement of distinct spectral...... fingerprints of the reaction mixture at specific time points during the course of the whole enzyme catalyzed reaction and employs multi-way analysis to detect the spectral changes. The methodology is demonstrated by spectral evolution profiling of Fourier Transform Infrared (FTIR) spectral fingerprints using...

  9. Photoreactivating enzyme from Escherichia coli

    International Nuclear Information System (INIS)

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

    1977-01-01

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

  10. Photoreactivating enzyme from Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

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

    1977-05-01

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

  11. Identification of Enzyme Genes Using Chemical Structure Alignments of Substrate-Product Pairs.

    Science.gov (United States)

    Moriya, Yuki; Yamada, Takuji; Okuda, Shujiro; Nakagawa, Zenichi; Kotera, Masaaki; Tokimatsu, Toshiaki; Kanehisa, Minoru; Goto, Susumu

    2016-03-28

    Although there are several databases that contain data on many metabolites and reactions in biochemical pathways, there is still a big gap in the numbers between experimentally identified enzymes and metabolites. It is supposed that many catalytic enzyme genes are still unknown. Although there are previous studies that estimate the number of candidate enzyme genes, these studies required some additional information aside from the structures of metabolites such as gene expression and order in the genome. In this study, we developed a novel method to identify a candidate enzyme gene of a reaction using the chemical structures of the substrate-product pair (reactant pair). The proposed method is based on a search for similar reactant pairs in a reference database and offers ortholog groups that possibly mediate the given reaction. We applied the proposed method to two experimentally validated reactions. As a result, we confirmed that the histidine transaminase was correctly identified. Although our method could not directly identify the asparagine oxo-acid transaminase, we successfully found the paralog gene most similar to the correct enzyme gene. We also applied our method to infer candidate enzyme genes in the mesaconate pathway. The advantage of our method lies in the prediction of possible genes for orphan enzyme reactions where any associated gene sequences are not determined yet. We believe that this approach will facilitate experimental identification of genes for orphan enzymes.

  12. Drug repositioning for enzyme modulator based on human metabolite-likeness.

    Science.gov (United States)

    Lee, Yoon Hyeok; Choi, Hojae; Park, Seongyong; Lee, Boah; Yi, Gwan-Su

    2017-05-31

    their corresponding metabolites. In addition, we showed that drug repositioning results of 10 enzymes were concordant with the literature evidence. This study introduced a method to predict the repositioning of known drugs to possible modulators of disease associated enzymes using human metabolite-likeness. We demonstrated that this approach works correctly with known antimetabolite drugs and showed that the proposed method has better performance compared to other drug target prediction methods in terms of enzyme modulators prediction. This study as a proof-of-concept showed how to apply metabolite-likeness to drug repositioning as well as potential in further expansion as we acquire more disease associated metabolite-target protein relations.

  13. General discussion about enzymes activities of radiation injury

    International Nuclear Information System (INIS)

    Vucicevic, M.; Sukalo, I.

    1989-01-01

    Researching reliable and practical indicators of radiation injury, however, is very interesting and considerable department of scientific studies, practical and theoretical. Enzymes activities are among biochemical indicators which are changed after radiation injury. Activity of these specific proteins is important in regulation of every biochemical reaction in existing beings. Biological macromolecules can be damaged by radiation or the cell permeability can be changed. All of these influence directly on enzymes activities. In this paper we present the review of the all important enzymes, indicators of the radiation injury, which variances on reference to normal values are significant of the functional and the structural changes of essential organs (author)

  14. General discussion about enzymes activities of radiation injury

    Energy Technology Data Exchange (ETDEWEB)

    Vucicevic, M; Sukalo, I [Institute of Nuclear Sciences Boris Kidric, Vinca, Beograd (Serbia and Montenegro)

    1989-07-01

    Researching reliable and practical indicators of radiation injury, however, is very interesting and considerable department of scientific studies, practical and theoretical. Enzymes activities are among biochemical indicators which are changed after radiation injury. Activity of these specific proteins is important in regulation of every biochemical reaction in existing beings. Biological macromolecules can be damaged by radiation or the cell permeability can be changed. All of these influence directly on enzymes activities. In this paper we present the review of the all important enzymes, indicators of the radiation injury, which variances on reference to normal values are significant of the functional and the structural changes of essential organs (author)

  15. Study of β-Galactosidase Enzyme Activity Produced by Lactobacilli in Milk and Cheese

    Directory of Open Access Journals (Sweden)

    J. Nowroozi

    2008-04-01

    Full Text Available Background and objectiveLactose intolerance is a discomfort state that occurs in some people after ingestion of milk and it is due to insufficient amount of beta galactosidase in the human gut to digest lactose. The aim of this study was to observe the presence of beta galactosidase enzyme produced by isolated lactobacilli from milk and cheese. Methods In this descriptive study, milk and cheese samples with different brand were bought from different shops. Lactobacilli were identified by plating samples on MRS medium, Gram staining and standard biochemical methods. β-galactosidase production by bacteria was assessed by X-Gal and ONPG methods. β-galactosidase was also detected by SDS-PAGE. ResultsFourteen genus of lactobacillus were isolated From 50 samples. All of the bacteria produced green color colonies on X-Gal plates (but in different times that indicated the presence of enzyme in the bacteria. All isolated lactobacilli were shown β-galactosidase activity in ONPG test. The highest enzymatic activity was seen in one strain of Lactobacillus Delbrueckii (1966 Miller unit /ml. In some bacteria (37% a strong β-galactosidase band(116-kDa was seen by SDS-PAGE.ConclusionAddition of beta galactosidase containing lactobacilli as a probiotic agent to milk, cheese, and other dairy products could ameliorate lactose intolerance. Meanwhile X-gal and ONPG methods which are simple, rapid and cheap can be used instead of SDS-PAGE.Keywords: Lactobacillus, Beta-Galactosidase, Nitrophenylgalactosids

  16. Pathomorphological and histochemical changes of internal organs of pigs during Granozan poisoning

    Energy Technology Data Exchange (ETDEWEB)

    Titov, V V; Titova, G S; Kochkurova, V N; Efremov, M I; Potapenko, N N

    1972-01-01

    Experiments were performed to determine the effects of organic mercury compounds on pigs. Pigs were fed grain which contained 1.2-12.5 mercury/kg. Enzyme activities of alkaline phosphatase and succinate dehydrogenase were inhibited in the liver, kidneys, myocardium, and gastric and intestinal epithelia. The onset of mercury poisoning was characterized by glycogen degeneration in the myocardium and granular and fatty dystrophy in the kidneys. The levels of mercury found in the muscles, liver and kidneys were 8, 50-150, and 84-150 mg/kg, respectively.

  17. Armored Urease: Enzyme-Bioconjugated Poly(acrylamide) Hydrogel as a Storage and Sensing Platform.

    Science.gov (United States)

    Kunduru, Konda R; Kutcherlapati, S N Raju; Arunbabu, Dhamodaran; Jana, Tushar

    2017-01-01

    Jack bean urease is an important enzyme not only because of its numerous uses in medical and other fields but also because of its historical significance-the first enzyme to be crystallized and also the first nickel metalloenzyme. This enzyme hydrolyzes urea into ammonia and carbon dioxide; however, the stability of this enzyme at ambient temperature is a bottleneck for its applicability. To improve urease stability, it was immobilized on different substrates, particularly on polymeric hydrogels. In this study, the enzyme was coupled covalently with poly(acrylamide) hydrogel with an yield of 18μmol/cm 3 . The hydrogel served as the nanoarmor and protected the enzyme against denaturation. The enzyme immobilized on the polymer hydrogel showed no loss in activity for more than 30 days at ambient temperature, whereas free enzyme lost its activity within a couple of hours. The Michaelis-Menten constant (K m ) for free and immobilized urease were 0.0256 and 0.2589mM, respectively, on the first day of the study. The K m of the immobilized enzyme was approximately 10 times higher than that of the free enzyme. The hydrogel technique was also used to prepare light diffracting polymerized colloidal crystal array in which urease enzyme was covalently immobilized. This system was applied for the detection of mercury (Hg 2+ ) with the lower limit as 1ppb, which is below the maximum contaminant limit (2ppb) for mercury ions in water. The experimental details of these studies are presented in this chapter. © 2017 Elsevier Inc. All rights reserved.

  18. An Inverse Michaelis–Menten Approach for Interfacial Enzyme Kinetics

    DEFF Research Database (Denmark)

    Kari, Jeppe; Andersen, Morten; Borch, Kim

    2017-01-01

    Interfacial enzyme reactions are ubiquitous both in vivo and in technical applications, but analysis of their kinetics remains controversial. In particular, it is unclear whether conventional Michaelis–Menten theory, which requires a large excess of substrate, can be applied. Here, an extensive...... experimental study of the enzymatic hydrolysis of insoluble cellulose indeed showed that the conventional approach had a limited applicability. Instead we argue that, unlike bulk reactions, interfacial enzyme catalysis may reach a steady-state condition in the opposite experimental limit, where...... for kinetic analyses of interfacial enzyme reactions and that its analogy to established theory provides a bridge to the accumulated understanding of steady-state enzyme kinetics. Finally, we show that the ratio of parameters from conventional and inverted Michaelis–Menten analysis reveals the density...

  19. Insight into cofactor recognition in arylamine N-acetyltransferase enzymes

    DEFF Research Database (Denmark)

    Xu, Ximing; Li de la Sierra-Gallay, Inés; Kubiak, Xavier Jean Philippe

    2015-01-01

    Arylamine N-acetyltransferases (NATs) are xenobiotic metabolizing enzymes that catalyze the acetyl-CoA-dependent acetylation of arylamines. To better understand the mode of binding of the cofactor by this family of enzymes, the structure of Mesorhizobium loti NAT1 [(RHILO)NAT1] was determined...... for Bacillus anthracis NAT1 and Homo sapiens NAT2. Therefore, in contrast to previous data, this study shows that different orthologous NATs can bind their cofactors in a similar way, suggesting that the mode of binding CoA in this family of enzymes is less diverse than previously thought. Moreover......, it supports the notion that the presence of the `mammalian/eukaryotic insertion loop' in certain NAT enzymes impacts the mode of binding CoA by imposing structural constraints....

  20. Extraction of erythrocyte enzymes for the preparation of polyhemoglobin-catalase-superoxide dismutase.

    Science.gov (United States)

    Gu, Jingsong; Chang, Thomas Ming Swi

    2009-01-01

    In sustained severe ischemia, reperfusion with oxygen carriers may result in ischemia-reperfusion injuries because of the release of damaging oxygen radicals. A nanobiotechnology-based polyhemogloin-calatase-superoxide dismutase can prevent this because the oxygen carrier, polyhemoglobin, is linked to antioxidant enzymes, catalase and superoxide dismutase. However, these antioxidant enzymes come from nonhuman sources and recombinant human enzymes are expensive. This paper describes our study on extracting these enzymes from red blood cells and analyzing the amount of enzymes needed for adequate protection from ischemia-reperfusion.

  1. Synthesis of non-steroidal anti-inflammatory drug analogues for selective studies on the COX-II enzyme

    International Nuclear Information System (INIS)

    Fleming, S.A.; Ridges, M.D.; Jensen, A.W.

    1996-01-01

    Synthesis of the azido substituted non-steroidal anti-inflammatory drug 2-(2,6-dichloroanilino)phenylacetic acid and isotope labeling of this compound have been performed and are described. Initial evaluation of the binding ability and photoreactivity indicates that this compound has potential for photoaffinity labeling as well as enzyme selectivity studies. (author)

  2. Enzymes in Poultry and Swine Nutrition | CRDI - Centre de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Book cover Enzymes in Poultry and Swine Nutrition. Auteur(s) : Ronald R. ... mechanisms. Such studies will enhance our understanding of the role of dietary enzymes in animal nutrition. ... Six équipes de chercheurs de classe mondiale étudieront comment surmonter la résistance au traitement des cancers les plus mortels.

  3. Structural Studies of Cinnamoyl-CoA Reductase and Cinnamyl-Alcohol Dehydrogenase, Key Enzymes of Monolignol Biosynthesis[C][W

    Science.gov (United States)

    Pan, Haiyun; Zhou, Rui; Louie, Gordon V.; Mühlemann, Joëlle K.; Bomati, Erin K.; Bowman, Marianne E.; Dudareva, Natalia; Dixon, Richard A.; Noel, Joseph P.; Wang, Xiaoqiang

    2014-01-01

    The enzymes cinnamoyl-CoA reductase (CCR) and cinnamyl alcohol dehydrogenase (CAD) catalyze the two key reduction reactions in the conversion of cinnamic acid derivatives into monolignol building blocks for lignin polymers in plant cell walls. Here, we describe detailed functional and structural analyses of CCRs from Medicago truncatula and Petunia hybrida and of an atypical CAD (CAD2) from M. truncatula. These enzymes are closely related members of the short-chain dehydrogenase/reductase (SDR) superfamily. Our structural studies support a reaction mechanism involving a canonical SDR catalytic triad in both CCR and CAD2 and an important role for an auxiliary cysteine unique to CCR. Site-directed mutants of CAD2 (Phe226Ala and Tyr136Phe) that enlarge the phenolic binding site result in a 4- to 10-fold increase in activity with sinapaldehyde, which in comparison to the smaller coumaraldehyde and coniferaldehyde substrates is disfavored by wild-type CAD2. This finding demonstrates the potential exploitation of rationally engineered forms of CCR and CAD2 for the targeted modification of monolignol composition in transgenic plants. Thermal denaturation measurements and structural comparisons of various liganded and unliganded forms of CCR and CAD2 highlight substantial conformational flexibility of these SDR enzymes, which plays an important role in the establishment of catalytically productive complexes of the enzymes with their NADPH and phenolic substrates. PMID:25217505

  4. Recent Advances in Marine Enzymes for Biotechnological Processes.

    Science.gov (United States)

    Lima, R N; Porto, A L M

    In the last decade, new trends in the food and pharmaceutical industries have increased concern for the quality and safety of products. The use of biocatalytic processes using marine enzymes has become an important and useful natural product for biotechnological applications. Bioprocesses using biocatalysts like marine enzymes (fungi, bacteria, plants, animals, algae, etc.) offer hyperthermostability, salt tolerance, barophilicity, cold adaptability, chemoselectivity, regioselectivity, and stereoselectivity. Currently, enzymatic methods are used to produce a large variety of products that humans consume, and the specific nature of the enzymes including processing under mild pH and temperature conditions result in fewer unwanted side-effects and by-products. This offers high selectivity in industrial processes. The marine habitat has been become increasingly studied because it represents a huge source potential biocatalysts. Enzymes include oxidoreductases, hydrolases, transferases, isomerases, ligases, and lyases that can be used in food and pharmaceutical applications. Finally, recent advances in biotechnological processes using enzymes of marine organisms (bacterial, fungi, algal, and sponges) are described and also our work on marine organisms from South America, especially marine-derived fungi and bacteria involved in biotransformations and biodegradation of organic compounds. © 2016 Elsevier Inc. All rights reserved.

  5. 21 CFR 864.9400 - Stabilized enzyme solution.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Stabilized enzyme solution. 864.9400 Section 864... and Blood Products § 864.9400 Stabilized enzyme solution. (a) Identification. A stabilized enzyme... enzyme solutions include papain, bromelin, ficin, and trypsin. (b) Classification. Class II (performance...

  6. Castor Oil Transesterification Catalysed by Liquid Enzymes

    DEFF Research Database (Denmark)

    Andrade, Thalles; Errico, Massimiliano; Christensen, Knud Villy

    2017-01-01

    In the present work, biodiesel production by reaction of non-edible castor oil with methanol under enzymatic catalysis is investigated. Two liquid enzymes were tested: Eversa Transform and Resinase HT. Reactions were performed at 35 °C and with a molar ratio of methanol to oil of 6:1. The reaction...... time was 8 hours. Stepwise addition of methanol was necessary to avoid enzyme inhibition by methanol. In order to minimize the enzyme costs, the influence of enzyme activity loss during reuse of both enzymes was evaluated under two distinct conditions. In the former, the enzymes were recovered...... and fully reused; in the latter, a mixture of 50 % reused and 50 % fresh enzymes was tested. In the case of total reuse after three cycles, both enzymes achieved only low conversions. The biodiesel content in the oil-phase using Eversa Transform was 94.21 % for the first cycle, 68.39 % in the second, and 33...

  7. A cross-sectional study of the relationship between serum liver enzymes level and the incidence of impaired fasting glucose in males and females.

    Science.gov (United States)

    Qin, Guangming; Lu, Lihong; Xiao, Yufei; Zhu, Yimiao; Pan, Wensheng; Xu, Xiang; Shen, Shengrong; Das, Undurti N

    2014-07-28

    The aim of this study was to investigate the possible correlation between levels of serum liver enzymes and impaired fasting glucose (IFG) in Chinese adults and to provide a new perspective for the prevention of pre-diabetes. Serum liver enzymes of the samples including alanine aminotransferase (ALT), aspartate aminotransferase (AST), and g-glutamyl transferase (GGT), as well as plasma glucose, blood lipids, and insulin, were measured. The cumulative incidences of IFG between different quartiles of liver enzymes were compared by the chi-square test. A logistic regression model (binary regression) was used to calculate the odds ratio (OR) of IFG with 95% confidence interval (95% CI). The total incidence of IFG was 20.3% and the cumulative incidence of IFG was higher in men compared to women. In both sexes, IFG is more prevalent in higher quartiles of liver enzymes. After adjusting for age, BMI, blood pressure, triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and total cholesterol (TC), the cumulative incidences of IFG were significantly higher in the highest quartiles of liver enzymes than in the lowest quartiles. A significantly higher cumulative incidence of IFG was found in the highest GGT quartile than in the lowest quartile for woman. The results of this study suggest that serum liver enzymes are related to the risk of IFG in Chinese adults. We infer that preserving the hepatic function may be an efficient way to prevent the development of IFG, especially in males.

  8. Fertile transgenic wheat from microprojectile bombardment of scutellar tissue.

    Science.gov (United States)

    Becker, D; Brettschneider, R; Lörz, H

    1994-02-01

    A reproducible transformation system for hexaploid wheat was developed based on particle bombardment of scutellar tissue of immature embryos. Particle bombardment was carried out using a PDS 1000/He gun. Plant material was bombarded with the plasmid pDB1 containing the beta-glucuronidase gene (uidA) under the control of the actin-1 promoter of rice, and the selectable marker gene bar (phosphinothricin acetyltransferase) under the control of the CaMV 35S promoter. Selection was carried out using the herbicide Basta (Glufosinate-ammonium). From a total number of 1050 bombarded immature embryos, in seven independent transformation experiments, 59 plants could be regenerated. Putative transformants were screened for enzyme activity by the histochemical GUS assay using cut leaf material and by spraying the whole plants with an aqueous solution of the herbicide Basta. Twelve regenerants survived Basta spraying and showed GUS-activity. Southern-blot analysis indicated the presence of introduced foreign genes in the genomic DNA of the transformants and both marker genes were present in all plants analysed. To date, four plants have been grown to maturity and set seed. Histochemically stained pollen grains showed a 1:1 segregation of the uidA gene in all plants tested. A 3:1 segregation of the introduced genes was demonstrated by enzyme activity tests and Southern blot analysis of R1 plants.

  9. Myocardial infarction false alarm: initial electrocardiogram and cardiac enzymes.

    Science.gov (United States)

    Gupta, Esha Das; Sakthiswary, Rajalingham

    2014-05-01

    The objectives of this study were to determine the incidence of a myocardial infarction "false alarm" and evaluate the efficacy of the initial electrocardiogram and cardiac enzymes in diagnosing myocardial infarction in Malaysia. We recruited patients who were admitted with suspected myocardial infarction from June to August 2008. The medical records of these patients were reviewed for the initial electrocardiogram, initial cardiac enzyme levels (creatinine kinase-MB and troponin T), and the final diagnosis upon discharge. The subjects were stratified into 2 groups: true myocardial infarction, and false alarm. 125 patients were enrolled in this study. Following admission and further evaluation, the diagnosis was revised from myocardial infarction to other medical conditions in 48 (38.4%) patients. The sensitivity and specificity of the initial ischemic electrocardiographic changes were 54.5% and 70.8%, respectively. Raised cardiac enzymes had a sensitivity of 44.3% and specificity of 95.8%. A significant proportion of patients in Malaysia are admitted with a false-alarm myocardial infarction. The efficacy of the electrocardiogram in diagnosing myocardial infarction in Malaysia was comparable to the findings of Western studies, but the cardiac enzymes had a much lower sensitivity.

  10. Biochemistry students' ideas about how an enzyme interacts with a substrate.

    Science.gov (United States)

    Linenberger, Kimberly J; Bretz, Stacey Lowery

    2015-01-01

    Enzyme-substrate interactions are a fundamental concept of biochemistry that is built upon throughout multiple biochemistry courses. Central to understanding enzyme-substrate interactions is specific knowledge of exactly how an enzyme and substrate interact. Within this narrower topic, students must understand the various binding sites on an enzyme and be able to reason from simplistic lock and key or induced fit models to the more complex energetics model of transition state theory. Learning to understand these many facets of enzyme-substrate interactions and reasoning from multiple models present challenges where students incorrectly make connections between concepts or make no connection at all. This study investigated biochemistry students' understanding of enzyme-substrate interactions through the use of clinical interviews and a national administration (N = 707) of the Enzyme-Substrate Interactions Concept Inventory. Findings include misconceptions regarding the nature of enzyme-substrate interactions, naïve ideas about the active site, a lack of energetically driven interactions, and an incomplete understanding of the specificity pocket. © 2015 by the International Union of Biochemistry and Molecular Biology.

  11. PROCESS FOR DUST-FREE ENZYME MANUFACTURE

    NARCIS (Netherlands)

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

    1994-01-01

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

  12. Applications of Microbial Enzymes in Food Industry

    Directory of Open Access Journals (Sweden)

    Binod Parameswaran

    2018-01-01

    Full Text Available The use of enzymes or microorganisms in food preparations is an age-old process. With the advancement of technology, novel enzymes with wide range of applications and specificity have been developed and new application areas are still being explored. Microorganisms such as bacteria, yeast and fungi and their enzymes are widely used in several food preparations for improving the taste and texture and they offer huge economic benefits to industries. Microbial enzymes are the preferred source to plants or animals due to several advantages such as easy, cost-effective and consistent production. The present review discusses the recent advancement in enzyme technology for food industries. A comprehensive list of enzymes used in food processing, the microbial source of these enzymes and the wide range of their application are discussed.

  13. Targeted quantification of functional enzyme dynamics in environmental samples for microbially mediated biogeochemical processes: Targeted quantification of functional enzyme dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Li, Minjing [School of Environmental Studies, China University of Geosciences, Wuhan 430074 People' s Republic of China; Gao, Yuqian [Pacific Northwest National Laboratory, Richland, WA 99354 USA; Qian, Wei-Jun [Pacific Northwest National Laboratory, Richland, WA 99354 USA; Shi, Liang [Pacific Northwest National Laboratory, Richland, WA 99354 USA; Liu, Yuanyuan [Pacific Northwest National Laboratory, Richland, WA 99354 USA; Nelson, William C. [Pacific Northwest National Laboratory, Richland, WA 99354 USA; Nicora, Carrie D. [Pacific Northwest National Laboratory, Richland, WA 99354 USA; Resch, Charles T. [Pacific Northwest National Laboratory, Richland, WA 99354 USA; Thompson, Christopher [Pacific Northwest National Laboratory, Richland, WA 99354 USA; Yan, Sen [School of Environmental Studies, China University of Geosciences, Wuhan 430074 People' s Republic of China; Fredrickson, James K. [Pacific Northwest National Laboratory, Richland, WA 99354 USA; Zachara, John M. [Pacific Northwest National Laboratory, Richland, WA 99354 USA; Liu, Chongxuan [Pacific Northwest National Laboratory, Richland, WA 99354 USA; School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055 People' s Republic of China

    2017-07-13

    Microbially mediated biogeochemical processes are catalyzed by enzymes that control the transformation of carbon, nitrogen, and other elements in environment. The dynamic linkage between enzymes and biogeochemical species transformation has, however, rarely been investigated because of the lack of analytical approaches to efficiently and reliably quantify enzymes and their dynamics in soils and sediments. Herein, we developed a signature peptide-based technique for sensitively quantifying dissimilatory and assimilatory enzymes using nitrate-reducing enzymes in a hyporheic zone sediment as an example. Moreover, the measured changes in enzyme concentration were found to correlate with the nitrate reduction rate in a way different from that inferred from biogeochemical models based on biomass or functional genes as surrogates for functional enzymes. This phenomenon has important implications for understanding and modeling the dynamics of microbial community functions and biogeochemical processes in environments. Our results also demonstrate the importance of enzyme quantification for the identification and interrogation of those biogeochemical processes with low metabolite concentrations as a result of faster enzyme-catalyzed consumption of metabolites than their production. The dynamic enzyme behaviors provide a basis for the development of enzyme-based models to describe the relationship between the microbial community and biogeochemical processes.

  14. Dipeptidyl peptidase IV in two human glioma cell lines

    Directory of Open Access Journals (Sweden)

    A Sedo

    2009-12-01

    Full Text Available There is growing evidence that dipeptidyl peptidase IV [DPP-IV, EC 3.4.14.5] takes part in the metabolism of biologically active peptides participating in the regulation of growth and transformation of glial cells. However, the knowledge on the DPP-IV expression in human glial and glioma cells is still very limited. In this study, using histochemical and biochemical techniques, the DPP-IV activity was demonstrated in two commercially available human glioma cell lines of different transformation degree, as represented by U373 astrocytoma (Grade III and U87 glioblastoma multiforme (Grade IV lines. Higher total activity of the enzyme, as well as its preferential localisation in the plasma membrane, was observed in U87 cells. Compared to U373 population, U87 cells were morphologically more pleiomorphic, they were cycling at lower rate and expressing less Glial Fibrillary Acidic Protein. The data revealed positive correlation between the degree of transformation of cells and activity of DPP-IV. Great difference in expression of this enzyme, together with the phenotypic differences of cells, makes these lines a suitable standard model for further 57 studies of function of this enzyme in human glioma cells.

  15. NRSA enzyme decomposition model data

    Data.gov (United States)

    U.S. Environmental Protection Agency — Microbial enzyme activities measured at more than 2000 US streams and rivers. These enzyme data were then used to predict organic matter decomposition and microbial...

  16. Interplay Between Oncoproteins and Antioxidant Enzymes in Esophageal Carcinoma Treated Without and With Chemoradiotherapy: A Prospective Study

    International Nuclear Information System (INIS)

    Kaur, Tranum; Gupta, Rajesh; Vaiphei, Kim; Kapoor, Rakesh; Gupta, N.M.; Khanduja, K.L.

    2008-01-01

    Purpose: To analyze p53, bcl-2, c-myc, and cyclooxygenase-2 protein expression changes and examine their relationship with various antioxidant enzymes in esophageal carcinoma patients. Methods and Materials: Patients in Group 1 underwent transhiatal esophagectomy and those in Group 2 were administered chemoradiotherapy followed by surgery after 4 weeks of neoadjuvant therapy. Results: The relationship analysis among the various protein markers and antioxidant enzymes showed an inverse correlation between bcl-2 and superoxide dismutase/catalase in tumor tissues, irrespective of the treatment arm followed. An important positive association was observed between bcl-2 and reduced glutathione levels in the tumor tissue of patients receiving neoadjuvant therapy. Another apoptosis-modulating marker, c-myc, in the tumor tissue of Group 2 patients showed similar pattern levels (high and low) as that of superoxide dismutase/catalase. The association of cyclooxygenase-2 and p53 with various antioxidant enzymes showed a significant positive correlation between cyclooxygenase-2 expression and catalase activity and an inverse trend between p53 expression and superoxide dismutase and catalase activity in the tumor tissue of patients given neoadjuvant therapy. In addition, patients with overexpressed p53 protein levels had lower glutathione peroxidase enzyme levels and vice versa in the tumor tissue of patients who had undergone surgery as their main mode of treatment. Conclusion: The results of this study broaden the insight into the relationships shared among oncoproteins and the antioxidant defense system, and this could be helpful in the clinical management of esophageal carcinoma

  17. An evaluation on elastase enzyme activity in gingival crevicular fluid in periodontitis

    Directory of Open Access Journals (Sweden)

    Qujeq D

    2003-08-01

    Full Text Available Statement of Problem: Changes in protein levels, host calls enzymes and inflammatory mediators in gingival"ncrevicular Fluid (GCF are considered as diagnostic indicators of Periodontitis."nPurpose: he aim of the present study was to measure the elastase enzyme activity in gingival crevicular Fluid"namong patients with periodontitis."nMaterial and Methods: In this study, 52 periodontitis patients (experimental group and 51 healthy subjects"nwithout any gingival inflammatio (control group were participated. Subjects of the periodontitis group"nshowed pockets of 4-5 mm depth without gingival enlargement and recession or pockets of 1-2 mm depth"nwith gingival recession. For enzyme activity measurement, lOOu,! of gingival fluid of each sample was mixed"nwith lOOu! of enzyme substrate on the tube. The mixture was incubated at 34°c for lh with a buffer solution"nof 1ml volume and absorbance was read at 410nm with spectrophotometer. The enzyme activity differences"nbetween two groups were analyzed by student t test."nResults: The elastase enzyme activity in gingival crevicular fluid in subjects with periodontium destruction"nand control subjects was 153±11.3 and 52.7±10.4 enzyme unit in ml per minute, respectively. The difference"nbetween groups was statistically significant (PO.05."nConclusion: Based on the findings of this study, the measurement of elastae enzyme activity could be a useful"nindication of tissue changes that may ultimately manifest clinically as periodontitis.

  18. [Study on soil enzyme activities and microbial biomass carbon in greenland irrigated with reclaimed water].

    Science.gov (United States)

    Pan, Neng; Hou, Zhen-An; Chen, Wei-Ping; Jiao, Wen-Tao; Peng, Chi; Liu, Wen

    2012-12-01

    The physicochemical properties of soils might be changed under the long-term reclaimed water irrigation. Its effects on soil biological activities have received great attentions. We collected surface soil samples from urban green spaces and suburban farmlands of Beijing. Soil microbial biomass carbon (SMBC), five types of soil enzyme activities (urease, alkaline phosphatase, invertase, dehydrogenase and catalase) and physicochemical indicators in soils were measured subsequently. SMBC and enzyme activities from green land soils irrigated with reclaimed water were higher than that of control treatments using drinking water, but the difference is not significant in farmland. The SMBC increased by 60.1% and 14.2% than those control treatments in 0-20 cm soil layer of green land and farmland, respectively. Compared with their respective controls, the activities of enzymes in 0-20 cm soil layer of green land and farmland were enhanced by an average of 36.7% and 7.4%, respectively. Investigation of SMBC and enzyme activities decreased with increasing of soil depth. Significantly difference was found between 0-10 cm and 10-20 cm soil layer in green land. Soil biological activities were improved with long-term reclaimed water irrigation in Beijing.

  19. Immobilization of Enzymes in Polymer Supports.

    Science.gov (United States)

    Conlon, Hugh D.; Walt, David R.

    1986-01-01

    Two experiments in which an enzyme is immobilized onto a polymeric support are described. The experiments (which also demonstrate two different polymer preparations) involve: (1) entrapping an enzyme in an acrylamide polymer; and (2) reacting the amino groups on the enzyme's (esterase) lysine residues with an activated polymer. (JN)

  20. Enzymic oxidation of carbon monoxide. II

    Energy Technology Data Exchange (ETDEWEB)

    Yagi, T

    1959-01-01

    An enzyme which catalyzes the oxidation of carbon monoxide into carbon dioxide was obtained in a cell free state from Desulfovibrio desulfuricans. The enzyme activity was assayed manometrically by measuring the rate of gas uptake under the atmosphere of carbon monoxide in the presence of benzyl-viologen as an oxidant. The optimum pH range was 7 to 8. The activity was slightly suppressed by illumination. The enzyme was more stable than hydrogenase or formate dehydrogenase against the heat treatment, suggesting that it is a different entity from these enzymes. In the absence of an added oxidant, the enzyme preparation produced hydrogen gas under the atmosphere of carbon monoxide. The phenomenon can be explained assuming the reductive decomposition of water. 17 references, 4 figures, 2 tables.

  1. Production of cellulolytic enzymes from ascomycetes

    DEFF Research Database (Denmark)

    Hansen, Gustav Hammerich; Lübeck, Mette; Frisvad, Jens Christian

    2015-01-01

    Optimizing production of cellulose degrading enzymes is of great interest in order to increase the feasibility of constructing biorefinery facilities for a sustainable supply of energy and chemical products. The ascomycete phylum has a large potential for the production of cellulolytic enzymes....... Although numerous enzymatic profiles have already been unraveled, the research has been covering only a limited number of species and genera, thus leaving many ascomycetes to be analyzed. Such analysis requires choosing appropriate media and cultivation methods that ensure enzyme profiles with high...... specificities and activities. However, the choice of media, cultivation methods and enzyme assays highly affect the enzyme activity profile observed. This review provides an overview of enzymatic profiles for several ascomycetes covering phylogenetically distinct genera and species. The profiles of cellulose...

  2. Metabolic enzymes: key modulators of functionality in cancer stem-like cells.

    Science.gov (United States)

    Dong, Bo-Wen; Qin, Guang-Ming; Luo, Yan; Mao, Jian-Shan

    2017-02-21

    Cancer Stem-like Cells (CSCs) are a subpopulation of cancer cells with self-renewal capacity and are important for the initiation, progression and recurrence of cancer diseases. The metabolic profile of CSCs is consistent with their stem-like properties. Studies have indicated that enzymes, the main regulators of cellular metabolism, dictate functionalities of CSCs in both catalysis-dependent and catalysis-independent manners. This paper reviews diverse studies of metabolic enzymes, and describes the effects of these enzymes on metabolic adaptation, gene transcription and signal transduction, in CSCs.

  3. Research Applications of Proteolytic Enzymes in Molecular Biology

    Directory of Open Access Journals (Sweden)

    József Tőzsér

    2013-11-01

    Full Text Available Proteolytic enzymes (also termed peptidases, proteases and proteinases are capable of hydrolyzing peptide bonds in proteins. They can be found in all living organisms, from viruses to animals and humans. Proteolytic enzymes have great medical and pharmaceutical importance due to their key role in biological processes and in the life-cycle of many pathogens. Proteases are extensively applied enzymes in several sectors of industry and biotechnology, furthermore, numerous research applications require their use, including production of Klenow fragments, peptide synthesis, digestion of unwanted proteins during nucleic acid purification, cell culturing and tissue dissociation, preparation of recombinant antibody fragments for research, diagnostics and therapy, exploration of the structure-function relationships by structural studies, removal of affinity tags from fusion proteins in recombinant protein techniques, peptide sequencing and proteolytic digestion of proteins in proteomics. The aim of this paper is to review the molecular biological aspects of proteolytic enzymes and summarize their applications in the life sciences.

  4. Computational Biochemistry-Enzyme Mechanisms Explored.

    Science.gov (United States)

    Culka, Martin; Gisdon, Florian J; Ullmann, G Matthias

    2017-01-01

    Understanding enzyme mechanisms is a major task to achieve in order to comprehend how living cells work. Recent advances in biomolecular research provide huge amount of data on enzyme kinetics and structure. The analysis of diverse experimental results and their combination into an overall picture is, however, often challenging. Microscopic details of the enzymatic processes are often anticipated based on several hints from macroscopic experimental data. Computational biochemistry aims at creation of a computational model of an enzyme in order to explain microscopic details of the catalytic process and reproduce or predict macroscopic experimental findings. Results of such computations are in part complementary to experimental data and provide an explanation of a biochemical process at the microscopic level. In order to evaluate the mechanism of an enzyme, a structural model is constructed which can be analyzed by several theoretical approaches. Several simulation methods can and should be combined to get a reliable picture of the process of interest. Furthermore, abstract models of biological systems can be constructed combining computational and experimental data. In this review, we discuss structural computational models of enzymatic systems. We first discuss various models to simulate enzyme catalysis. Furthermore, we review various approaches how to characterize the enzyme mechanism both qualitatively and quantitatively using different modeling approaches. © 2017 Elsevier Inc. All rights reserved.

  5. Restriction enzyme body doubles and PCR cloning: on the general use of type IIs restriction enzymes for cloning.

    Science.gov (United States)

    Tóth, Eszter; Huszár, Krisztina; Bencsura, Petra; Kulcsár, Péter István; Vodicska, Barbara; Nyeste, Antal; Welker, Zsombor; Tóth, Szilvia; Welker, Ervin

    2014-01-01

    The procedure described here allows the cloning of PCR fragments containing a recognition site of the restriction endonuclease (Type IIP) used for cloning in the sequence of the insert. A Type IIS endonuclease--a Body Double of the Type IIP enzyme--is used to generate the same protruding palindrome. Thus, the insert can be cloned to the Type IIP site of the vector without digesting the PCR product with the same Type IIP enzyme. We achieve this by incorporating the recognition site of a Type IIS restriction enzyme that cleaves the DNA outside of its recognition site in the PCR primer in such a way that the cutting positions straddle the desired overhang sequence. Digestion of the PCR product by the Body Double generates the required overhang. Hitherto the use of Type IIS restriction enzymes in cloning reactions has only been used for special applications, the approach presented here makes Type IIS enzymes as useful as Type IIP enzymes for general cloning purposes. To assist in finding Body Double enzymes, we summarised the available Type IIS enzymes which are potentially useful for Body Double cloning and created an online program (http://group.szbk.u-szeged.hu/welkergr/body_double/index.html) for the selection of suitable Body Double enzymes and the design of the appropriate primers.

  6. A phylogenetic analysis of normal modes evolution in enzymes and its relationship to enzyme function.

    Science.gov (United States)

    Lai, Jason; Jin, Jing; Kubelka, Jan; Liberles, David A

    2012-09-21

    Since the dynamic nature of protein structures is essential for enzymatic function, it is expected that functional evolution can be inferred from the changes in protein dynamics. However, dynamics can also diverge neutrally with sequence substitution between enzymes without changes of function. In this study, a phylogenetic approach is implemented to explore the relationship between enzyme dynamics and function through evolutionary history. Protein dynamics are described by normal mode analysis based on a simplified harmonic potential force field applied to the reduced C(α) representation of the protein structure while enzymatic function is described by Enzyme Commission numbers. Similarity of the binding pocket dynamics at each branch of the protein family's phylogeny was analyzed in two ways: (1) explicitly by quantifying the normal mode overlap calculated for the reconstructed ancestral proteins at each end and (2) implicitly using a diffusion model to obtain the reconstructed lineage-specific changes in the normal modes. Both explicit and implicit ancestral reconstruction identified generally faster rates of change in dynamics compared with the expected change from neutral evolution at the branches of potential functional divergences for the α-amylase, D-isomer-specific 2-hydroxyacid dehydrogenase, and copper-containing amine oxidase protein families. Normal mode analysis added additional information over just comparing the RMSD of static structures. However, the branch-specific changes were not statistically significant compared to background function-independent neutral rates of change of dynamic properties and blind application of the analysis would not enable prediction of changes in enzyme specificity. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Studies on cell-free metabolism: ethanol production by a yeast glycolytic system reconstituted from purified enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Welch, P; Scopes, R K

    1985-07-01

    A reconstituted glycolytic system has been established from individually purified enzymes to simulate the conversion of glucose to ethanol plus CO/sub 2/ by yeast. Sustained and extensive conversion occurred provided that input of glucose matched the rate of ATP degradation appropriately. ATPase activity could be replaced by arsenate, which uncoupled ATP synthesis from glycolysis. The mode of uncoupling was investigated, and it was concluded that the artificial intermediate, 1-arseno-3-phosphoglycerate, has a half-life of no more than a few milliseconds. Arsenate at 4 mM concentration could simulate the equivalent of 10 ..mu..mol/ml min. of ATPase activity. The reconstituted enzyme system was capable of totally degrading one M (18% w/v) glucose in 8 hours giving 9% (w/v) ethanol. The levels of metabolites during metabolism were measured to detect rate-limiting steps. The successful operation of the reconstituted enzyme system demonstrates that it is possible to carry out complex chemical transformations with multiple enzyme systems in vitro. 36 references.

  8. Sequence dependent DNA conformations: Raman spectroscopic studies and a model of action of restriction enzymes

    International Nuclear Information System (INIS)

    Nishimura, Y.

    1985-01-01

    Raman spectra have been examined to clarify the polymorphic forms of DNA, A, B, and Z forms. From an analysis the authors found that the guanine ring breathing vibration is sensitive to its local conformation. Examination of nine crystals of guanosine residues in which the local conformations are well established revealed that a guanosine residue with a C3'endo-anti gives a strong line at 666+-2 cm/sup -1/, O4'endo-anti at 682 cm/sup -1/, C1'exo-anti at 673 cm/sup -1/, C2'endo-anti at 677 cm/sup -1/ and syn-forms around 625 cm/sup -1/. Using this characteristic line, they were able to obtain the local conformations of guanosine moieties in poly(dG-dC). Such a sequence derived variation is suggested to be recognized by sequence specific proteins such as restriction enzymes. The authors found a correlation between sequence dependent DNA conformation and a mode of action of restriction enzymes. The cutting mode of restriction enzymes is classified into three groups. The classification of whether the products have blunt ends, two-base-long cohesive ends, or four-base-long cohesive ends depends primarily on the substrate, not on the enzyme. It is suggested that sequence dependent DNA conformation causes such a classification by the use of the Calladine-Dickerson analysis. In the recognition of restriction enzymes, the methyl group in a certain sequence is considered to play an important role by changing the local conformation of DNA

  9. Enzymes for ecdysteroid biosynthesis: their biological functions in insects and beyond.

    Science.gov (United States)

    Niwa, Ryusuke; Niwa, Yuko S

    2014-01-01

    Steroid hormones are responsible for the coordinated regulation of many aspects of biological processes in multicellular organisms. Since the last century, many studies have identified and characterized steroidogenic enzymes in vertebrates, including mammals. However, much less is known about invertebrate steroidogenic enzymes. In the last 15 years, a number of steroidogenic enzymes and their functions have been characterized in ecdysozoan animals, especially in the fruit fly Drosophila melanogaster. In this review, we summarize the latest knowledge of enzymes crucial for synthesizing ecdysteroids, the principal insect steroid hormones. We also discuss the functional conservation and diversity of ecdysteroidogenic enzymes in other insects and even non-insect species, such as nematodes, vertebrates, and lower eukaryotes.

  10. Ethanol from wood. Cellulase enzyme production

    Energy Technology Data Exchange (ETDEWEB)

    Szengyel, Zsolt

    2000-03-01

    Conversion of biomass to liquid fuels, such as ethanol, has been investigated during the past decades. First due to the oil crisis of the 1970s and lately because of concerns about greenhouse effect, ethanol has been found to be a suitable substitute for gasoline in transportation. Although ethanol is produced in large quantities from corn starch, the conversion of lignocellulosic biomass to ethanol is rather problematic. However, cellulosic raw materials are important as they are available in large quantities from agriculture and forestry. One of the most extensively investigated processes is the enzymatic process, in which fungal cellulolytic enzymes are used to convert the cellulose content of the biomass to glucose, which is then fermented to ethanol. In order to make the raw material accessible to biological attack, it has to be pretreated first. The most successful method, which has been evaluated for various lignocellulosic materials, is the steam pretreatment. In this thesis the utilization of steam pretreated willow (hardwood) and spruce (softwood) was examined for enzyme production using a filamentous fungus T. reesei RUT C30. Various carbon sources originating from the steam pretreated materials have been investigated. The replacement of the solid carbon source with a liquid carbon source, as well as the effect of pH, was studied. The effect of toxic compounds generated during pretreatment was also examined. Comparative study of softwood and hardwood showed that steam pretreated hardwood is a better carbon source than softwood. The hydrolytic potential of enzyme solutions produced on wood derived carbon sources was better compared to commercial cellulases. Also enzyme solutions produced on steam pretreated spruce showed less sensitivity towards toxic compounds formed during steam pretreatment.

  11. Cellulolytic enzyme compositions and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Iyer, Prashant; Gaspar, Armindo Ribiero; Croonenberghs, James; Binder, Thomas P.

    2017-07-25

    The present invention relates enzyme composition comprising a cellulolytic preparation and an acetylxylan esterase (AXE); and the used of cellulolytic enzyme compositions for hydrolyzing acetylated cellulosic material. Finally the invention also relates to processes of producing fermentation products from acetylated cellulosic materials using a cellulolytic enzyme composition of the invention.

  12. Enzyme kinetics of hevamine, a chitinase from the rubber tree Hevea brasiliensis

    NARCIS (Netherlands)

    Bokma, Evert; Barends, Thomas; Terwisscha van Scheltinga, Anke C.; Dijkstra, Bauke W.; Beintema, Jaap J.

    2000-01-01

    The enzyme kinetics of hevamine, a chitinase from the rubber tree Hevea brasiliensis, were studied in detail with a new enzyme assay. In this assay, the enzyme reaction products were derivatized by reductive coupling to a chromophore, Products mere separated by HPLC and the amount of product was

  13. Stabilizing effect of biochar on soil extracellular enzymes after a denaturing stress.

    Science.gov (United States)

    Elzobair, Khalid A; Stromberger, Mary E; Ippolito, James A

    2016-01-01

    Stabilizing extracellular enzymes may maintain enzymatic activity while protecting enzymes from proteolysis and denaturation. A study determined whether a fast pyrolysis hardwood biochar (CQuest™) would reduce evaporative losses, subsequently stabilizing soil extracellular enzymes and prohibiting potential enzymatic activity loss following a denaturing stress (microwaving). Soil was incubated in the presence of biochar (0%, 1%, 2%, 5%, or 10% by wt.) for 36 days and then exposed to microwave energies (0, 400, 800, 1600, or 3200 J g(-1) soil). Soil enzymes (β-glucosidase, β-d-cellobiosidase, N-acetyl-β-glucosaminidase, phosphatase, leucine aminopeptidase, β-xylosidase) were analyzed by fluorescence-based assays. Biochar amendment reduced leucine aminopeptidase and β-xylosidase potential activity after the incubation period and prior to stress exposure. The 10% biochar rate reduced soil water loss at the lowest stress level (400 J microwave energy g(-1) soil). Enzyme stabilization was demonstrated for β-xylosidase; intermediate biochar application rates prevented a complete loss of this enzyme's potential activity after soil was exposed to 400 (1% biochar treatment) or 1600 (5% biochar treatment) J microwave energy g(-1) soil. Remaining enzyme potential activities were not affected by biochar, and activities decreased with increasing stress levels. We concluded that biochar has the potential to reduce evaporative soil water losses and stabilize certain extracellular enzymes where activity is maintained after a denaturing stress; this effect was biochar rate and enzyme dependent. While biochar may reduce the potential activity of certain soil extracellular enzymes, this phenomenon was not universal as the majority of enzymes assayed in this study were unaffected by exposure to biochar. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Cellulase enzyme and biomass utilization

    African Journals Online (AJOL)

    STORAGESEVER

    2009-06-03

    Jun 3, 2009 ... human population grows and economic development. However, the current .... conditions and the production cost of the related enzyme system. Therefore ... Given the importance of this enzyme to these so many industries,.

  15. Prescription patterns of enzyme-containing products in South Africa over a 2-year period

    Directory of Open Access Journals (Sweden)

    Ilse Truter

    2014-09-01

    Full Text Available Enzymes are traded in five categories, namely medical (intervention, diagnostic (detection and quantification, molecular biology, biofuel and industrial. Therapeutic enzymes have been investigated for different uses, for example, for the treatment of genetic disorders, blood clotting disorders, cancer and infectious diseases and for burn debridement. No studies on the prescription of enzyme-containing products in South Africa could be found. Enzymes are classified in the Monthly Index of Medical Specialities under digestants, enzymes and fibrinolytics. The primary aim of this study was to investigate the prescription patterns and cost of enzyme-containing products in South Africa. A private health-care medicines claims database for 2010 and 2011 of approximately 4.5 million records was analysed retrospectively. Enzyme-containing products constituted a small percentage of medical insurance claims (only 0.02% of approximately 4.5 million claims for products and procedures, yet they were relatively expensive. A total of 906 products was prescribed at a cost of almost ZAR2 million over the 2 years. Hyaluronidase was the most frequently prescribed (60.04%, followed by pancreatin-containing products (34.66%. Pancreatin (lipase/ protease/amylase is primarily used in the management of pancreatic exocrine insufficiency. The average cost per hyaluronidase prescription paid by the medical insurance schemes was ZAR280. Other enzyme-containing products prescribed were imiglucerase, alteplase and tenecteplase. Imiglucerase was overall the most expensive. Alteplase, tenecteplase and streptokinase are antithrombotic enzymes that are used in the treatment of acute myocardial infarction or ischaemic stroke. Streptokinase, regarded as the most affordable antithrombotic enzyme, was not prescribed during the period under study. With the growing opportunities for enzymes for therapeutics, the use of enzyme-containing products which are comparatively expensive require

  16. Chronic ethanol feeding modulates the synthesis of digestive enzymes

    International Nuclear Information System (INIS)

    Ponnappa, B.C.; Hoek, J.B.; Rubin, E.

    1987-01-01

    The effects of chronic ethanol feeding on pancreatic protein synthesis were investigated. Protein synthesis was assessed by studying the rate of incorporation of 3 H-leucine into TCA-precipitable proteins in isolated pancreatic acini from rats. Chronic ethanol ingestion increased the rate of pancreatic protein synthesis by 2-4 fold. The onset of the increase in protein synthesis was detectable two days after ethanol feeding, reached a maximum after 7 days and remained unchanged after 4 months on the ethanol-containing diet. The rate of synthesis of individual digestive enzymes was studied by SDS-PAGE on extracts obtained from purified zymogen granules. Ethanol feeding induced an increase in the rate of synthesis of most of the digestive enzymes; chymotrypsinogen, trypsinogen and an unidentified protein were increased to a greater extent than other digestive enzymes. By contrast, the synthesis of amylase was selectively decreased after ethanol feeding. These results suggest that chronic ethanol ingestion has specific effects on the rate of synthesis of individual digestive enzymes in the exocrine pancreas

  17. Enzyme replacement and substrate reduction therapy for Gaucher disease.

    Science.gov (United States)

    Shemesh, Elad; Deroma, Laura; Bembi, Bruno; Deegan, Patrick; Hollak, Carla; Weinreb, Neal J; Cox, Timothy M

    2015-03-27

    Gaucher disease, a rare disorder, is caused by inherited deficiency of the enzyme glucocerebrosidase. It is unique among the ultra-orphan disorders in that four treatments are currently approved by various regulatory authorities for use in routine clinical practice. Hitherto, because of the relatively few people affected worldwide, many of whom started therapy during a prolonged period when there were essentially no alternatives to imiglucerase, these treatments have not been systematically evaluated in studies such as randomized controlled trials now considered necessary to generate the highest level of clinical evidence. To summarize all available randomized controlled study data on the efficacy and safety of enzyme replacement therapies and substrate reduction therapy for treating Gaucher disease. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Inborn Errors of Metabolism Trials Register. Additional searches were conducted on ClinicalTrials.gov for any ongoing studies with potential interim results, and through PubMed. We also searched the reference lists of relevant articles and reviews.Date of last search: 07 August 2014. All randomized and quasi-randomized controlled studies (including open-label studies and cross-over studies) assessing enzyme replacement therapy or substrate reduction therapy, or both, in all types of Gaucher disease were included. Two authors independently assessed the risk of bias in the included studies, and extracted relevant data. Of the 488 studies retrieved by the electronic searches, eight met the inclusion criteria and were analysed (300 participants). Response parameters were restricted to haemoglobin concentration, platelet count, spleen and liver volume and serum biomarkers (chitotriosidase and CCL18). Only one publication reported a 'low risk of bias' score in all parameters assessed, and all studies included were randomized.Four studies reported the responses to enzyme replacement therapy of previously

  18. Studies on non-steroidal inhibitors of aromatase enzyme; 4-(aryl/heteroaryl)-2-(pyrimidin-2-yl)thiazole derivatives.

    Science.gov (United States)

    Sahin, Zafer; Ertas, Merve; Berk, Barkın; Biltekin, Sevde Nur; Yurttas, Leyla; Demirayak, Seref

    2018-05-01

    Steroidal and non-steroidal aromatase inhibitors target the suppression of estrogen biosynthesis in the treatment of breast cancer. Researchers have increasingly focused on developing non-steroidal derivatives for their potential clinical use avoiding steroidal side-effects. Non-steroidal derivatives generally have planar aromatic structures attached to the azole ring system. One part of this ring system comprises functional groups that inhibit aromatization through the coordination of the haem group of the aromatase enzyme. Replacement of the triazole ring system and development of aromatic/cyclic structures of the side chain can increase selectivity over aromatase enzyme inhibition. In this study, 4-(aryl/heteroaryl)-2-(pyrimidin-2-yl)thiazole derivatives were synthesized and physical analyses and structural determination studies were performed. The IC 50 values were determined by a fluorescence-based aromatase inhibition assay and compound 1 (4-(2-hydroxyphenyl)-2-(pyrimidine-2-yl)thiazole) were found potent inhibitor of enzyme (IC 50 :0.42 nM). Then, their antiproliferative activity over MCF-7 and HEK-293 cell lines was evaluated using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Compounds 1, 7, 8, 13, 15, 18, 21 were active against MCF-7 breast cancer cells. Lastly, a series of docking experiments were undertaken to analyze the crystal structure of human placental aromatase and identify the possible interactions between the most active structure and the active site. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Photosynthetic fuel for heterologous enzymes

    DEFF Research Database (Denmark)

    Mellor, Silas Busck; Vavitsas, Konstantinos; Nielsen, Agnieszka Janina Zygadlo

    2017-01-01

    of reducing power. Recent work on the metabolic engineering of photosynthetic organisms has shown that the electron carriers such as ferredoxin and flavodoxin can be used to couple heterologous enzymes to photosynthetic reducing power. Because these proteins have a plethora of interaction partners and rely...... on electrostatically steered complex formation, they form productive electron transfer complexes with non-native enzymes. A handful of examples demonstrate channeling of photosynthetic electrons to drive the activity of heterologous enzymes, and these focus mainly on hydrogenases and cytochrome P450s. However......, competition from native pathways and inefficient electron transfer rates present major obstacles, which limit the productivity of heterologous reactions coupled to photosynthesis. We discuss specific approaches to address these bottlenecks and ensure high productivity of such enzymes in a photosynthetic...

  20. Deletion/insertion polymorphism of the angiotensin-converting enzyme gene and white matter hyperintensities in dementia: A pilot study.

    NARCIS (Netherlands)

    Purandare, N.; Oude Voshaar, R.C.; Davidson, Y.; Gibbons, L.; Hardicre, J.; Byrne, J.; McCollum, C.N.; Jackson, A.; Burns, A.; Mann, D.M.

    2006-01-01

    OBJECTIVES: To examine the association between the angiotensin-converting enzyme (ACE) deletion/insertion (D/I) polymorphism and white matter hyperintensities (WMHs) in patients with dementia. DESIGN: Observational pilot study with adjustment for potential confounders using analysis of covariance.