Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.21 (beta-glucosidase)
 3,280 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The pseudo-oligosaccharides, validamycins, showed potent inhibitory activity against trehalase of Rhizoctonia solani while no significant inhibition was exhibited against cellulase, pectinase, chitinase, alpha-amylase, alpha- and beta-glucosidases. In particular, validoxylamine A strongly inhibited trehalase in a competitive manner with a Ki value of 1.9 X 10(-9) M. The uptake of the antibiotic into the cell and the amount of the intracellular trehalose were investigated by incubating the washed mycelia of R. solani with validamycins. It was found that validamycin A is transported into the cell and hydrolyzed therein by a beta-glucosidase yielding validoxylamine A with greater inhibitory activity. Also validamycin A containing beta-D-glucosyl residue is more favorably taken up into the cell than validamycin D containing alpha-D-glucosyl residue or their common aglycone, validoxylamine A. In addition, validamycin A suppressed the in vivo degradation of the intracellular trehalose at very low concentration of 0.1 microgram/ml.
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PMID:Effect of validamycins on glycohydrolases of Rhizoctonia solani. 358 21

A mixture of enzymes (mycolase) capable of lysing yeast cell walls was prepared from culture filtrates of Physarum polycephalum. The enzymes present in mycolase included chitinase, beta-1,3-glucanases and exo-glycosidases. The pH optima of these enzymes were in the range 3.5-5.0 and they had low activities at pH 7.0. Mycolase produced spheroplasts from Candida pseudotropicalis and, unlike commercial enzyme preparations such as L1, chitinase, beta, 1,3-glucanase and beta-glucosidase, had some candicidal activity in vitro against C. pseudotropicalis and C. albicans. Mycolase potentiated the antifungal activity of amphotericin B against C. pseudotropicalis grown in shake flask culture but did not potentiate the antifungal activity of the antibiotic against similar cultures of C. albicans; indeed antagonism between mycolase and amphotericin B was sometimes observed with the latter yeast. Mycolase caused an approximately two-fold increase in the total and viable counts of cultures of C. albicans inoculated with stationary phase cells. These increases, which were observed within about 30 min, were attributed to mycolase inducing the premature release of viable buds from 'lag' phase cells. Mycolase also increased the rate at which C. albicans formed germ tubes when the yeast was cultured in a medium containing serum. Mycolase alone or in combination with amphotericin B did not appreciably enhance phagocytosis or intracellular killing of the yeasts by unstimulated mouse peritoneal macrophages. Studies on mice infected systemically with C. albicans showed that mycolase only slightly enhanced amphotericin B therapy.
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PMID:Effect of mycolase and amphotericin B on Candida albicans and Candida pseudotropicalis in vitro and in vivo. 389 68

An enzymatic profile of 20 strains of Pseudomonas maltophilia was undertaken with conventional plate tests, API ZYM, and 4-methylumbelliferyl-conjugated substrates. All strains produced DNase, RNase, arbutinase, esterases and lipases, mucinase, acid and alkaline phosphatases, alkaline pyrophosphate diesterase, phosphoamidase, beta-glucosidase, leucine arylamidase, and acetatase and were hemolytic for horse, sheep, and rabbit blood. The majority of strains produced chitinase, hyaluronidase, albuminase, valine arylamidase, trypsin, alpha- and beta-glucosidases, and N-acetyl-beta-glucosaminidase. API ZYM and 4-methylumbelliferyl-conjugated substrate assays are rapid, simple, specific, and sensitive and may be useful as diagnostic aids in the identification of P. maltophilia and other pseudomonads.
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PMID:Enzymatic profile of Pseudomonas maltophilia. 681 50

The presence of chitinase activity in human serum has recently been described by us. On that occasion we speculated on the possible role of mammalian chitinases as a defense mechanism against chitin-containing pathogens. The results of the present study substantiate our hypothesis. We demonstrate and partially characterize the chitinase activities that are present in plasma of guinea pigs and in homogenates of A.fumigatus with the aid of the substrates MU-[GlcNAc]2,3 and also with glycol [3H]chitin. Upon infection with A.fumigatus the serum chitinase activity levels in the circulation of pathogen-free guinea pigs increased in a time-dependent manner. The increase was also dependent on the size of the infecting fungal inoculum. Antifungal treatment diminished the increases. The increased chitinase activity was of guinea pig origin. The activity of beta-hexosaminidase showed a very slight increase subsequent to the infection. The activities of three other enzymes of lysosomal origin (alpha-mannosidase, beta-galactosidase and beta-glucosidase) did not increase.
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PMID:Chitinase levels in guinea pig blood are increased after systemic infection with Aspergillus fumigatus. 892 58

Abstract The Pomeranian Bight in the southern Baltic Sea is characterized by a huge input of nutrients from the Oder river. This input shows seasonal variation. In winter, the nutrients are introduced in inorganic form. Particulate organic material is dominant in the growth season (summer/autumn). From 1993 to 1996, extracellular enzyme activities (alkaline phosphatase, peptidase, alpha-, beta-glucosidase, and chitinase) were investigated to describe microbial reaction to the input of organic material and the modification of introduced material. The distribution patterns of extracellular enzyme activities in salinity gradients were studied, in response to the nutrient load. These activities were distinctly lower in winter than in summer and autumn. A close relationship to other biological parameters (Chl a, POC, PON) was observed during the growth season, but not in winter. Changes in peptidase and phosphatase activities between summer and autumn were also observed. The peptidase activity was 9 to 72 times higher in autumn than in summer. In contrast, the alkaline phosphatase activity was 5 to 30 times higher in summer than in autumn. The organic compound turnover rate/hydrolysis rate (To/Hr) ratio is a relative index which describes the coupling of enzymatic hydrolysis and utilization of monomers from investigated substrates (carbohydrates and proteins). In summer, after dilution, the raised To/Hr quotients of glucose indicated limited importance for hydrolysis products in bacterial turnover. The increased demand for glucose resulted in a parallel decrease in monosaccharides. In autumn, the relationship between the turnover of glucose and amino acids and the supply of these substances by enzymatic degradation remained at the same level.
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PMID:Extracellular Enzyme Activities in Relation to Hydrodynamics in the Pomeranian Bight (Southern Baltic Sea). 985 5

A commercially available almond emulsin beta-glucosidase preparation has been reported to have chitobiose activity, and can hydrolyze chitin substrates due to a chitinase present in the enzyme preparation. This beta-glucosidase preparation was used to investigate hydrolytic activity on five chitosan samples with different molecular weight and degree of deacetylation. The degree of deacetylation and molecular weight of the chitosan samples were determined using a circular dichroism and a viscometric method, respectively. The hydrolytic activity of this beta-glucosidase preparation on chitosan was monitored viscometrically as the most convenient means of screening. Solutions of chitosan in pH 5.0 acetate buffer were prepared using the different viscosity grades of chitosan. The specific viscosity, measured after addition of beta-glucosidase to the above solutions, decreased dramatically over time in comparison to that of the respective control mixture without enzyme. Eadie-Hofstee plots established that hydrolysis of chitosan by this enzyme preparation obeyed Michaelis-Menten kinetics. Apparent Michaelis-Menten parameters and initial degradation rates were calculated and compared to determine the influences of the degree of deacetylation and molecular weight on the hydrolysis. The results show that higher molecular weight and higher degree of deacetylation chitosans possessed a lower affinity for the enzyme and a slower degradation rate. Faster degradation rates, then, are expected with lower molecular weight and low degree of deacetylation chitosans. Hydrolysis of these chitosan samples confirms the existence of a chitinase in the almond emulsin beta-glucosidase preparation, and further studies are warranted.
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PMID:In vitro degradation of chitosan by a commercial enzyme preparation: effect of molecular weight and degree of deacetylation. 1137 67

The maize rhm1 mutant resists Bipolaris maydis, the causal agent of Southern corn leaf blight, by producing small necrotic lesions surrounded by chlorotic haloes. The rhm1 and wild-type lesions contain viable fungus in equal frequency, but fungal sporulation was markedly inhibited on rhm1. The levels of the pathogenesis-related (PR) proteins chitinase, PR1, and peroxidase differ little between rhm1 and wild type, with or without B. maydis inoculation. The global mRNA profiles surveyed revealed hundreds of cDNA fragments that were twofold or more induced or suppressed in rhm1 and wild-type plants following B. maydis inoculation. Nonetheless, between rhm1 and wild type, only 0.4 to 0.7% of the cDNA fragments were expressed differentially by twofold or more. Among the up-regulated genes in rhm1 was beta-glucosidase glu1, which prompted a test of whether rhm1 resistance depends upon the antimicrobial compound 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one or other hydroxamic acids whose glucosyl conjugates are preferred substrates for the Glu1 enzyme. Double mutants of rhm1 and bx1, a hydroxamic acid-deficient mutant, indicate that rhm1 resistance is hydroxamic acid independent. The rhm1 resistance presently appears to operate via a mechanism unlike those of previously described resistance genes.
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PMID:Maize rhm1 resistance to Bipolaris maydis is associated with few differences in pathogenesis-related proteins and global mRNA profiles. 1149 66

Coccidioides immitis is a human respiratory pathogen characterized by a parasitic cycle that is unique among fungi that cause systemic mycoses. Biochemical, molecular and immunological studies of the cell wall of C. immitis have focused on three distinct events of parasitic cell differentiation: isotropic growth, segmentation and endosporulation. Current investigations of each developmental phase in vitro include the identification, expression analysis, and disruption of synthase and hydrolase genes that are suspected to have key roles in morphogenesis. Temporal expression of families of beta-glucosidase and chitinase genes are of particular interest because their products may participate in wall modification during both isotropic growth and endosporulation and, thereby, represent potential molecular targets for novel antifungal drugs. Furthermore, our immunological studies of these and other isolated parasitic cell-wall components have resulted in the identification of antigens with demonstrated impact on host response to coccidioidal infection. C. immitis has proved to be an excellent model for fungal cell-wall research.
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PMID:The parasitic cell wall of Coccidioides immitis. 1180 Feb 67

In yeast and other fungi, cell division, cell shape, and growth depend on the coordinated synthesis and degradation of cell wall polymers. We have developed a reliable and efficient micro method to determine Saccharomyces cerevisiae cell wall composition that distinguishes between beta1,3- and beta1,6-glucan. The method is based on the sequential treatment of cell walls with specific hydrolytic enzymes followed by dialysis. The low molecular weight (MW) products thus separated account for each particular cell wall polymer. The method can be applied to as little as 50-100 mg (wet wt) of radioactively labeled cells. A combination of chitinase and recombinant beta-1,3-glucanase is initially used, releasing all of the chitin and 60-65% of the beta1,3-glucan from the cell walls. Next, recombinant endo-beta-1,6-glucanase from Trichoderma harzianum is utilized to release all the beta-1,6-glucan present in the wall. The chromatographic pattern of endoglucanase digested beta-1,6-glucan provides a characteristic "fingerprint" of beta-1,6-glucan and the fine structure of the oligosaccharides in this pattern was determined by 1H NMR and electrospray ionization mass spectroscopy. The final enzymatic step uses laminarinase and beta-glucosidase to release the remaining beta-1,3-glucan. The cell wall mannan remains as a high MW fraction at the end of the fractionation procedure. Good sensitivity and correlation with cell wall composition determined by traditional methods were observed for wild-type and several cell wall mutants.
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PMID:A refined method for the determination of Saccharomyces cerevisiae cell wall composition and beta-1,6-glucan fine structure. 1181 78

A multiparticulate system of chitosan hydrogel beads has been investigated for colon-specific delivery of macromolecules using fluorescein isothiocyanate-labeled bovine serum albumin as a model protein. The hydrogel bead was formed by polyelectrolyte complexation of chitosan with its counterion, tripolyphosphate (TPP). The protein release experiments were carried out in vitro under different conditions to simulate the pH and times likely to be encountered during intestinal transit to the colon. The results show that the hydrogel beads were degraded by rat cecal and colonic enzymes, resulting in a marked acceleration in the release of protein. The ability of rat cecal and colonic enzymes to degrade chitosan hydrogel beads was independent of pretreatment conditions. A commercial beta-glucosidase preparation containing a chitinase did not have a similar effect on the chitosan bead, even though it has been found to mimic the degradation function of rat cecal and colonic enzymes in vitro for chitosan in solution. Degradation of the chitosan-TPP hydrogel beads in the presence of rat cecal and colonic enzymes indicates the potential of this multiparticulate system to serve as a carrier to deliver macromolecules specifically to the colon.
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PMID:An in vitro evaluation of a chitosan-containing multiparticulate system for macromolecule delivery to the colon. 1205 5


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