Lawton J B, Mekas C I
J Pharm Pharmacol. 1985 Jun;37(6):396-400. doi: 10.1111/j.2042-7158.1985.tb03022.x.
A study has been made of the interaction of selected polycations with pepsin A (E.C. 3.4.23.1). Protamine, polybrene, spermine, spermidine and poly(L-lysine) all acted as inhibitors of the enzyme at low concentrations, but at higher concentrations of the polycations the inhibition was less pronounced. A more detailed study of the anomalous inhibition was made using protamine, polybrene and poly(L-lysine) and it was shown experimentally that, when used by themselves, each of these polycations acted as a weak proteolytic catalyst. The order of catalytic effectiveness was: protamine greater than polybrene much greater than poly(L-lysine). Thus, it is now possible to explain why the observed inhibition of pepsin decreases when the concentration of the inhibiting polycation is increased.
对选定的多阳离子与胃蛋白酶A（E.C. 3.4.23.1）之间的相互作用进行了研究。鱼精蛋白、聚凝胺、精胺、亚精胺和聚（L-赖氨酸）在低浓度时均作为该酶的抑制剂，但在多阳离子浓度较高时，抑制作用不那么明显。使用鱼精蛋白、聚凝胺和聚（L-赖氨酸）对这种异常抑制进行了更详细的研究，实验表明，这些多阳离子单独使用时，每种都作为一种弱蛋白水解催化剂起作用。催化效果的顺序为：鱼精蛋白＞聚凝胺＞＞聚（L-赖氨酸）。因此，现在可以解释为什么当抑制性多阳离子的浓度增加时，观察到的胃蛋白酶抑制作用会降低。
