Comparative study of the inhibition of alpha-glucosidase, alpha-amylase, and cyclomaltodextrin glucanosyltransferase by acarbose, isoacarbose, and acarviosine-glucose.
Bacillus stearothermophilus maltogenic amylase hydrolyzes the first glycosidic linkage of acarbose to give acarviosine-glucose. In the presence of carbohydrate acceptors, acarviosine-glucose is primarily transferred to the C-6 position of the acceptor. When d-glucose is the acceptor, isoacarbose is formed. Acarbose, acarviosine-glucose, and isoacarbose were compared as inhibitors of alpha-glucosidase, alpha-amylase, and cyclomaltodextrin glucanosyltransferase. The three inhibitors were found to be competitive inhibitors for alpha-glucosidase and mixed noncompetitive inhibitors for alpha-amylase and cyclomaltodextrin glucanosyltransferase. The K(i) values were dependent on the type of enzyme and their source. Acarviosine-glucose was a potent inhibitor for baker's yeast alpha-glucosidase, inhibiting 430 times more than acarbose, and was an excellent inhibitor for cyclomaltodextrin glucanosyltransferase, inhibiting 6 times more than acarbose. Isoacarbose was the most effective inhibitor of alpha-amylase and cyclomaltodextrin glucanosyltransferase, inhibiting 15.2 and 2.0 times more than acarbose, respectively.
Kim
M J
MJ
Research Center for New Bio-Materials in Agriculture and Department of Food Science and Technology, Seoul National University, Suwon, 441-744, Korea.
Lee
S B
SB
Lee
H S
HS
Lee
S Y
SY
Baek
J S
JS
Kim
D
D
Moon
T W
TW
Robyt
J F
JF
Park
K H
KH
D020909:Acarbose / Q000031:analogs & derivatives* / Q000494:pharmacology; D000606:Amino Sugars; D000818:Animals; D001407:Bacillus / Q000201:enzymology; D002240:Carbohydrate Sequence; D004187:Disaccharides / Q000494:pharmacology; D005964:Glucosyltransferases / Q000037:antagonists & inhibitors*; D065089:Glycoside Hydrolase Inhibitors; D008956:Models, Chemical; D008969:Molecular Sequence Data; D051381:Rats; D013552:Swine; D000516:alpha-Amylases / Q000037:antagonists & inhibitors*
D000606:Amino Sugars; D004187:Disaccharides; D065089:Glycoside Hydrolase Inhibitors; C076099:acarviosine; D005964:Glucosyltransferases; C019963:cyclomaltodextrin glucanotransferase; D000516:alpha-Amylases; D020909:Acarbose