The differential enzyme sensitivity of rat immunoglobulin G subclasses to papain and pepsin.
The differential enzyme sensitivity of rat immunoglobulin G subclasses to papain and pepsin.
复制标题
大鼠免疫球蛋白 G 亚类对木瓜蛋白酶和胃蛋白酶的酶敏感性差异。
DOI：
10.1016/0161-5890(80)90087-5
复制
发表时间：
1980
影响因子：
3.6
通讯作者：
H. Bazin
中科院分区：
文献类型：
--
作者：
J. Rousseaux;G. Biserte;H. Bazin
用木瓜酶和胃酶在几种实验条件下对不同亚类的单抗和正常大鼠血清中的IgG2a进行了降解。当这些蛋白在没有半胱氨酸或低浓度的还原剂(0.001M)的情况下孵育时，发现IgG1对木瓜蛋白酶的抗性最强，而IgG2a最敏感。0.01M半胱氨酸存在下的木瓜酶消化可使大鼠IgG1、IgG2a和IgG2b释放出非共价Fc。IgG1和IgG2a对胃酶降解的抵抗力最强，而IgG2c对该酶的作用非常敏感。增加胃酶浓度和添加半胱氨酸的效果因免疫球蛋白亚类不同而不同。胃蛋白酶Fc(PFC)片段在大鼠IgG2a和IgG2c中大量产生，而在IgG1的胃酶消化中缺失。并对其抗蛋白降解的机制及其可能的生物学意义进行了讨论。
Monoclonal IgG belonging to the different rat IgG subclasses and IgG2a from normal rat serum were subjected to enzymatic degradation with papain and pepsin under several experimental conditions. IgG1 was found the most resistant to papain and IgG2a the most sensitive when the proteins were incubated in absence of cysteine or with low concentrations of the reducing agent (0.001M). Papain digestion in the presence of 0.01Mcysteine led to the release of non-covalent Fc from rat IgG1, IgG2a and IgG2b. IgG1 and IgG2a were the most resistant to pepsin degradation, whereas IgG2c had very high sensitivity to the action of this enzyme. The effects of the increase of pepsin concentration and of the addition of cysteine were found to be different according to the IgG subclass. The pepsin Fc (pFc) fragment was generated in significant yields from rat IgG2a and IgG2c, but was absent from pepsin digests of IgG1. The mechanisms of resistance to proteolysis and its possible biological significance have been discussed.