Inhibitory effects of tannin on human salivary alpha-amylase. Related Articles Inhibitory effects of tannin on human salivary alpha-amylase. Biochem Biophys Res Commun. 2004 Jul 9;319(4):1265-71 Authors: Kandra L, Gyémánt G, Zajácz A, Batta G Here, we first report on the effectiveness and specificity of tannin inhibition of 2-chloro-4-nitrophenyl-4-O-beta-d-galactopyranosylmaltoside hydrolysis that is catalyzed by human salivary alpha-amylase (HSA). Tannin was gallotannin in which quinic acid was esterified with 2-7 units of gallic acid. A number of studies establish that polyphenols-like tannins-may prevent oral diseases, e.g., dental caries. Kinetic analyses confirmed that the inhibition of hydrolysis is a mixed non-competitive type and only one molecule of tannin binds to the active site or the secondary site of the enzyme. Since Dixon plots were linear, product formation could be excluded from the enzyme-substrate-inhibitor complex (ESI). Kinetic constants calculated from secondary plots and non-linear regression are almost identical, thereby confirming the suggested model. Kinetic constants (K(EI) = 9.03 microgmL(-1), K(ESI) = 47.84 microgmL(-1)) show that tannin is as an effective inhibitor of HSA as acarbose and indicate a higher stability for the enzyme-inhibitor complex than ESI. PMID: 15194503 [PubMed - indexed for MEDLINE] Sucrase and maltase activities in supragingival dental plaque in humans of st... Related Articles Sucrase and maltase activities in supragingival dental plaque in humans of streptococcal, actinomyces and lactobacilli species. Scand J Dent Res. 1984 Apr;92(2):97-108 Authors: Fiehn NE, Moe D 20 reference strains and 72 isolated strains from dental plaque of streptococci, actinomyces, and lactobacilli species were examined for sucrase and maltase activities. The type of sucrase in the different strains was determined by use of the alpha-glucosidase inhibitor, acarbose. The enzyme activities were determined as formation of monosaccharide, and quantitated spectrophotometrically. Although variations occurred in enzyme activities between reference and isolated strains, the same general pattern was noticed. Strains of Streptococcus mutans and S. salivarius showed regularly the highest sucrase activities, followed by strains of Actinomyces viscosus and A. naeslundii. Most lactobacilli belonged to the bacteria with low sucrase activity like S. sanguis and S. mitior. In some lactobacilli strains, however, a high sucrase activity was observed. The level of sucrase activity in S. mutans strains was dependent on biotype/serotype, as strains of biotype V/serotype e showed high activities, biotypes I and IV corresponding to serotypes c, f, and d showed intermediate activity, and biotype III/serotype a always showed low activity. In most of the strains the sucrases were composed of enzymes with specificity against both alpha-glucosidic linkage and beta-fructosidic linkage of the sucrose molecule, but in varying ratios. In all species, exept S. sanguis and S. mitior, lower maltase than sucrase activity was observed, but even in the two species mentioned the maltase activities were relatively low. On the basis of observations of selected reference strains in every species examined both sucrases and maltases are to some extent inducible. PMID: 6372064 [PubMed - indexed for MEDLINE] Effect of seven inhibitors on invertases in homogenates of human dental plaque. Related Articles Effect of seven inhibitors on invertases in homogenates of human dental plaque. Scand J Dent Res. 1983 Jun;91(3):175-81 Authors: Fiehn NE, Moe D Seven known alpha-glucosidase/beta-fructosidase inhibitors were examined for inhibitory effect against invertases in pooled human dental plaque. The inhibitors used were acarbose, Trestatin, nojirimycin, 1-deoxynojirimycin, glucono-delta-lactam, conduritol-B-epoxide, and Hoe 467A. Plaque homogenates were incubated with 14C-labelled sucrose and invertase activity was assayed by determination of radio-labelled monosaccharide after paper chromatography. Conduritol-B-epoxide, acarbose, and Trestatin reduced the invertase activity an average of 62%, 51%, and 35% respectively. The other inhibitors affected the enzyme activity negligibly. By combining conduritol-B-epoxide with acarbose or Trestatin in other plaque homogenates the inhibition of invertases increased from 35% to 61%. This observation supported the concept that the invertases in dental plaque consist of both alpha-glucosidases and beta-fructosidases. PMID: 6224287 [PubMed - indexed for MEDLINE] Effect of alpha-amylase and alpha-glucosidase inhibitors on caries incidence ... Related Articles Effect of alpha-amylase and alpha-glucosidase inhibitors on caries incidence and plaque accumulation in rats. Caries Res. 1983;17(4):353-6 Authors: Mörmann JE, Schmid R, Mühlemann HR PMID: 6191863 [PubMed - indexed for MEDLINE] Effect of the alpha-glucosidase inhibitor, acarbose, on disaccharide splittin... Related Articles Effect of the alpha-glucosidase inhibitor, acarbose, on disaccharide splitting enzymes in human dental plaque. Scand J Dent Res. 1982 Apr;90(2):124-30 Authors: Fiehn NE, Moe D Inhibition of microbial enzymes in human dental plaque catalyzing the cleavage of the disaccharides maltose, sucrose and lactose was carried out with the alpha-glucosidase inhibitor, acarbose. The maltases from plaque homogenates were totally inhibited, whereas the inhibition of the invertases varied considerably. With increasing inhibitor concentrations, from 1 mM to 50 mM, the inhibition of the invertases increased. Preincubation for 30 min of the plaque homogenate with inhibitor resulted in a 20% increase of the inhibition of invertase activity. The inhibitor showed non-competitive inhibition of the invertases in the homogenates, whereas the maltases were competitively inhibited. The lactases were not inhibited at all. The invertases from human dental plaque may be alpha-glucosidases and/or beta-fructosidases. PMID: 6803351 [PubMed - indexed for MEDLINE]

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