The effect of acid proteinase inhibitors on chicken pepsin.
1. The activity of chicken pepsin was partially inhibited by dimethyl-(2-hydroxy-5-nitrobenzyl)sulphonium bromide, but was unaffected by p-bromophenacyl bromide. 2. In the presence of Cu2+, diazoacetylnorleucine methyl ester completely inactivated chicken pepsin with the incorporation of 1 mol/mol. The mechanism of the reaction was similar to that with pig pepsin. 3. Chicken pepsin was completely inactivated by 2-diazo-4-bromoacetophenone in the presence of Cu2+. 4. Chicken pepsin was almost completely inactivated by 1,2-epoxy-3-(p-nitrophenoxy)propane at 25 degrees C, 3-4mol of inhibitor/mol being incorporated. The reaction at 10 degrees C was investigated briefly. 5. Calf chymosin was inactivated by 1,2-epoxy-3-(p-nitrophenoxy)propane at 10 degrees C, the incorporation of 1 mol/mol being required for complete inhibition. 6. The characteristics of the reactions of chicken pepsin with the above compounds were compared with those of other acid proteinases.
D000098:Acetophenones / Q000494:pharmacology; D000596:Amino Acids / Q000032:analysis; D001391:Azo Compounds / Q000494:pharmacology; D012085:Chymosin / Q000037:antagonists & inhibitors; D003300:Copper; D006863:Hydrogen-Ion Concentration; D009596:Nitrophenols / Q000494:pharmacology; D009646:Norleucine / Q000031:analogs & derivatives / Q000494:pharmacology; D010434:Pepsin A / Q000037:antagonists & inhibitors*; D011506:Proteins / Q000032:analysis
D000098:Acetophenones; D000596:Amino Acids; D001391:Azo Compounds; D009596:Nitrophenols; D011506:Proteins; D003300:Copper; D009646:Norleucine; D010434:Pepsin A; D012085:Chymosin; C006821:4-bromophenacyl bromide