Effect of alpha-glucosidase inhibitor on human pancreatic and salivary alpha-amylase.
The mode of inhibition of a new complex oligosaccharide that inhibits the alpha-glucoside hydrolase activity of pancreatic and salivary alpha-amylase was studied. Kinetic analysis revealed a non-competitive type of inhibition with a Ki of 1.47 +/- 0.03 micrograms when tested against human pancreatic alpha-amylase and 3.89 +/- 0.08 micrograms against human salivary alpha-amylase. The inhibitory action of alpha-glucoside hydrolase inhibitor (alpha-GHI) on pancreatic amylase was observed over a wide range of pH (6.0--7.9), whereas the inhibition of salivary amylase was optimal at pH 6.5. Column chromatographic investigations suggested the possible formation of an enzyme-inhibitor complex because the mixture of alpha-GHI and pancreatic alpha-amylase was eluted as a single component through a Sephadex G200 column. However, this enzyme-inhibitor complex was easily separated into each component and the enzyme activity was fully recovered after electrophoresis.
D000681:Amylases / Q000037:antagonists & inhibitors*; D002850:Chromatography, Gel; D005959:Glucosidases / Q000037:antagonists & inhibitors*; D065089:Glycoside Hydrolase Inhibitors; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010179:Pancreas / Q000201:enzymology*; D012463:Saliva / Q000201:enzymology*; D000516:alpha-Amylases / Q000037:antagonists & inhibitors*
D065089:Glycoside Hydrolase Inhibitors; D000681:Amylases; D005959:Glucosidases; D000516:alpha-Amylases