Deutsch H F, Jabusch J R, Lin K T
J Biol Chem. 1977 Jan 25;252(2):555-9.
A polymorphic form of the high activity or C-type of horse erythrocyte carbonic anhydrase has been isolated. It has been designated C2 and differs from the usual C1 form by having a cysteine replacement for arginine at residue 180. This second cysteine, unlike the other, is highly reactive. Isolation of the C2 isozyme by the usual methods results in most of it forming a mixed disulfide with glutathione and this product designated as C3 has an increased anodic mobility. The enzymatic activity and immunologic reactivity of both the C2 and C3 components are the same as for the usual C1 form of the enzyme. The C2 form can be stabilized by alkylation and the carboxamidomethyl derivative has been isolated in crystalline form.
已分离出高活性或C型马红细胞碳酸酐酶的一种多晶型形式。它被命名为C2，与常见的C1形式不同，在第180位残基处精氨酸被半胱氨酸取代。这第二个半胱氨酸与其他半胱氨酸不同，具有高反应活性。用常规方法分离C2同工酶时，大部分会与谷胱甘肽形成混合二硫键，这种产物被命名为C3，其阳极迁移率增加。C2和C3组分的酶活性和免疫反应性与该酶常见的C1形式相同。C2形式可通过烷基化稳定，并且已分离出结晶形式的羧酰胺甲基衍生物。
