[Proteolysis of the barley protein, hordein]

Gordein isolated from barley according to Baxter's method was exposed to proteolytic enzymes at optimal medium pH. As regards the capability of gordein splitting the enzymes can be arranged in the following way: pronase greater than elastase greater than pepsin greater than papain greater than chymotrypsin greater than trypsin. A mixture of three enzymes (trypsin, chymotrypsin and elastase) taken in the amount 1/3 of the usually used concentration provoked a more powerful splitting than each of the enzymes used alone. According to the electrophoresis in polyacrylamide gel data the action of elastase led to the splitting of the high-molecular-weight fraction of gordein with accumulation of the low-molecular weight one. Preheating of gordein for 30 min at 100 degrees C increased its papain-induced splitting by 3.3 times, chymotrypsin-induced by 2.6 times, trypsin-induced by 30%, and pepsin-induced splitting by 23%. Heating did not affect the rate of gordein splitting by elastase. Pretreatment of gordein with pepsin increased over 2 times its splitting under the effect of trypsin and chymotrypsin.