抄録
Soybean saponin has been reported to change the nature of proteins. Thus, crude saponin fraction or isolated soyasaponin I was added to Bowman-Birk inhibitor (BBI) from soybeans to evaluate the effect on its trypsin-inhibiting activity. The soybean saponin and soyasaponin I used in the experiment had little effect on tryptic activity. The trypsin-inhibiting activity of the mixture consisting of BBI and saponin was gradually enhanced by increasing saponin fraction or isolated soyasaponin I. Circular dichroism (CD) spectra of BBI were proportionally changed with the increase in soyasaponin I to imply change in structure of BBI. These results suggested that the conformational change by saponin caused enhancement of the trypsin-inhibiting activity of BBI.
