A novel method for the assay of alpha-glucosidase inhibitory activity using a multi-channel oxygen sensor.
The quantification of glucose by using a multi-channel dissolved oxygen (DO) meter (DOX96) with immobilized glucose oxidase (GOD) and mutarotase (MUT) was performed. An evaluation of the inhibitory activities for alpha-glucosidase (AGH) by modifying our batch-type pseudo-in vivo assay system [Oki et al.; Biol Pharm. Bull., 2000, 232, 1084] was also performed using a DOX96. When 45 U/well GOD and 18.75 U/well MUT were immobilized on the surface of a gelatin membrane on the electrodes, the response shown by the decrease percent of DO (%) obtained with 8 electrode wells in the same row was linear with the glucose concentration up to 3.3 mM and a correlation coefficient larger than 0.9. To estimate the AGH inhibitory activity, AGH-immobilized Sepharose supports in the well of a silent screen plate were used. The IC50 values of acarbose and 1-deoxynojirimycin, a medicinal inhibitor for diabetes, were 0.70 +/- 0.08 microM and 0.40 +/- 0.13 microM, respectively, and coincided well with those by a pseudo-in vivo assay.
Matsumoto
Kiyoshi
K
Laboratory of Food Analysis, Division of Food Biotechnology, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan. kmatsu@agr.kyushu-u.ac.jp
Takemata
Kayoko
K
Takayama
Kiyofumi
K
Abesundara
Kanthi J M
KJ
Matsui
Toshiro
T
Katayama
Hideo
H
D017485:1-Deoxynojirimycin / Q000494:pharmacology; D020909:Acarbose / Q000494:pharmacology; D000818:Animals; D015374:Biosensing Techniques / Q000379:methods / Q000592:standards*; D002138:Calibration; D002238:Carbohydrate Epimerases; D004566:Electrodes / Q000592:standards; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D004800:Enzymes, Immobilized / Q000037:antagonists & inhibitors; D005947:Glucose / Q000032:analysis*; D065089:Glycoside Hydrolase Inhibitors; D020128:Inhibitory Concentration 50; D010100:Oxygen / Q000032:analysis*; D051381:Rats; D000520:alpha-Glucosidases
D004791:Enzyme Inhibitors; D004800:Enzymes, Immobilized; D065089:Glycoside Hydrolase Inhibitors; D017485:1-Deoxynojirimycin; D000520:alpha-Glucosidases; D002238:Carbohydrate Epimerases; C019646:aldose 1-epimerase; D005947:Glucose; D010100:Oxygen; D020909:Acarbose