Characterization of kintoki bean (Phaseolus vulgaris) alpha-amylase inhibitor: inhibitory activities against human salivary and porcine pancreatic alpha-amylases and activity changes by proteolytic digestion.
The effects of some experimental parameters on alpha-amylase inhibition by an alpha-amylase inhibitor from kintoki bean were examined. The rate of inhibition against pancreatic alpha-amylase increased with a rise in temperature to 50 degrees C, but the inhibition of salivary alpha-amylase reached a maximum above 35 degrees C. Although an increase in NaCl concentration to 1.5 M caused an increase in the inhibitory activities against both amylases, these inhibitory activities tended to decrease above 1.5 M NaCl. The effects of proteolytic digestion on the amylase inhibitory activity were also studied. The inhibitor was slightly inactivated by pepsin digestion for 2 h. Although the inhibitor rapidly lost the inhibitory activity by chymotrypsin digestion within 2 h, it was quite resistant to proteolytic digestion by trypsin.
Yoshikawa
H
H
Department of Living Science, Koka Women's Junior College, Kyoto, Japan.
Kotaru
M
M
Tanaka
C
C
Ikeuchi
T
T
Kawabata
M
M
D000818:Animals; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D007887:Fabaceae; D006801:Humans; D066298:In Vitro Techniques; D037102:Lectins / Q000494:pharmacology*; D009994:Osmolar Concentration; D010179:Pancreas / Q000201:enzymology*; D010434:Pepsin A / Q000378:metabolism; D037121:Plant Lectins; D010940:Plant Proteins / Q000494:pharmacology*; D010946:Plants, Medicinal; D012463:Saliva / Q000201:enzymology*; D013552:Swine; D013696:Temperature; D000516:alpha-Amylases / Q000037:antagonists & inhibitors*
D004791:Enzyme Inhibitors; D037102:Lectins; D037121:Plant Lectins; D010940:Plant Proteins; C061510:alpha-amylase inhibitor, Phaseolus vulgaris; D000516:alpha-Amylases; D010434:Pepsin A