KINETIC-ANALYSIS OF THE INHIBITION BY MELANOIDIN OF TRYPSIN

The inhibition by melanoidin of trypsin was investigated in a kinetic approach. Melanoidin was prepared by the Maillard reaction between D-g lucose and glycine, and BANA was used as a substrate. The inhibition w as found to follow a non-competitive mode with a K-i of 5.8% and to be exerted through an electrostatic interaction between melanoidin and t rypsin. Approximately 20% of the activity of trypsin survived even at a greatly increased concentration of melanoidin. The inhibiting mechan ism of melanoidin might be due to an allosteric effect, which was prob ably different from a proteinaceous inhibitor such as ovoinhibitor dim inishing trypsin-activity completely. The melanoidin molecule was thou ght to trap a great number of trypsin molecules, binding them and redu cing their activity.