Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.20 (alpha-glucosidase)
 4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Toluene-treated cells of Streptococcus bovis JB1 phosphorylated cellobiose, glucose, maltose, and sucrose by the phosphoenolpyruvate-dependent phosphotransferase system. Glucose phosphorylation was constitutive, while all three disaccharide systems were inducible. Competition experiments indicated that separate phosphotransferase systems (enzymes II) existed for glucose, maltose, and sucrose. [14C]maltose transport was inhibited by excess (10 mM) glucose and to a lesser extent by sucrose (90 and 46%, respectively). [14C]glucose and [14C]sucrose transports were not inhibited by an excess of maltose. Since [14C]maltose phosphorylation in triethanolamine buffer was increased 160-fold as the concentration of Pi was increased from 0 to 100 mM, a maltose phosphorylase (Km for Pi, 9.5 mM) was present, and this activity was inducible. Maltose was also hydrolyzed by an inducible maltase. Glucose 1-phosphate arising from the maltose phosphorylase was metabolized by a constitutive phosphoglucomutase that was specific for alpha-glucose 1-phosphate (Km, 0.8 mM). Only sucrose-grown cells possessed sucrose hydrolase activity (Km, 3.1 mM), and this activity was much lower than the sucrose phosphotransferase system and sucrose-phosphate hydrolase activities.
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PMID:Transport and phosphorylation of disaccharides by the ruminal bacterium Streptococcus bovis. 282 69

Bacillus anthracis could be distinguished from the taxonomically related species B. cereus, B. mycoides, and B. thuringiensis by a comparison of glycosidase activities. All the bacilli tested possessed alpha-glucosidase activity, as evidenced by the hydrolysis of p-nitrophenyl-alpha-D-glucoside. In B. anthracis, the glucosidase activity could be enhanced by the addition of agents which damage cellular surface structures. Treatment of B. anthracis strains with toluene. Triton X-100, or mutanolysin or cellular disruption by sonication resulted in higher rates of alpha-glucoside hydrolysis than were accomplished by cells suspended in buffer. It is suggested that intact B. anthracis cells have a limited permeability to the glucosidase substrate. In contrast to the results obtained for B. anthracis, Triton X-100 markedly diminished the enzymatic hydrolysis of p-nitrophenyl-alpha-D-glucoside by strains of B. cereus, B. mycoides, and B. thuringiensis. Triton X-100 also enhanced the alpha-maltosidase activity of B. anthracis but not that of the other bacilli. B. mycoides possessed an apparently inducible N-acetylglucosaminidase although the enzyme was absent in B. anthracis. The glucosaminidase was inducible in the presence of p-nitrophenyl-N-acetylglucosamine in the absence of conventional nitrogen sources. Chloramphenicol prevented the induction of the glucosaminidase in B. mycoides. In several B. cereus and all B. thuringiensis strains, the glucosaminidase was constitutive. The results suggest a means for the rapid laboratory differentiation of B. anthracis from other closely related bacilli. Assays for alpha-glucosidase and alpha-maltosidase, in the presence and absence of Triton X-100, can be used to distinguish B. anthracis from B. cereus, B. mycoides, and B. thuringiensis. Similarly, the hydrolysis of p-nitrophenyl-beta-N-acetylglucosamine induced by B. mycoides but not by B. anthracis provides an additional means for differentiating these similar bacilli.
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PMID:Glycosidase activities of Bacillus anthracis. 642 87

Cells of the fission yeast Schizosaccharomyces pombe were permeabilized by treatment with toluene-ethanol. The permeabilized cells lost the bulk of the internal trehalose pool while most of the alkaline phosphatase, invertase, alpha-glucosidase, or neutral trehalase activities located inside the cells remained unaffected. This system was used as an in situ assay to determine the involvement of trehalose in enzyme protection during thermal treatments. The addition of trehalose to suspensions of permeabilized cells resulted in a sugar-dependent thermoprotection of the internal marker enzymes. This approach demonstrates that in whole cells of the fission yeast trehalose plays a physiological role as a protective molecule against thermal denaturation of cellular enzymes.
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PMID:Increased thermal stability of the enzyme content in permeabilized whole cells from the fission yeast Schizosaccharomyces pombe by exogenous trehalose and other compounds. 859 Apr 7

The objectives of this study were to examine the effects of growth substrate and extracellular pH on phosphoenolpyruvate-dependent glucose phosphorylation as well as to examine how maltose is phosphorylated by the ruminal bacterium Megasphaera elsdenii B159. Phosphoenolpyruvate-dependent glucose phosphorylation by toluene-treated cells was constitutive, and glucose phosphorylation was reduced by 69% at pH 5.0. When toluene-treated cells were incubated in histidine buffer, little maltose phosphorylation occurred in the absence of inorganic phosphate. However, the addition of increasing concentrations of either potassium or sodium phosphate increased maltose phosphorylation. Maximal phosphorylation activity was observed at between 25 and 50 mM of either inorganic phosphate source. Compared with the control incubations, maltose phosphorylation was increased over threefold with 25 mM of either potassium or sodium phosphate. Phosphoglucomutase activity was detected in cell extracts of M. elsdenii B159, and this enzyme had a K(m) of 3.2 mM for glucose-1-P and a V(max) of 1836 nmol of NADP(+) reduced/mg of protein per min. Maltose was also hydrolyzed by an inducible maltase (K(m), 1.19 mM). To our knowledge, this is the first report of a maltose phosphorylase and a maltase in M. elsdenii.
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PMID:Factors affecting glucose and maltose phosphorylation by the ruminal bacterium Megasphaera elsdenii. 1082 81