Structural studies on the murine IA alloantigens. II. Molecular weight characterization of the products of the I-A and I-E/C subregions.
Structural studies on the murine IA alloantigens. II. Molecular weight characterization of the products of the I-A and I-E/C subregions.
复制标题
鼠 IA 同种异体抗原的结构研究。
DOI：
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发表时间：
1978
影响因子：
4.4
通讯作者：
Ellen S. Vitetta
中科院分区：
文献类型：
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作者：
Richard G. Cook;Jonathan W. Uhr;J. Capra;Ellen S. Vitetta
小鼠脾细胞用3 H-和14 C-氨基酸进行放射性标记;通过免疫沉淀分离由I-A和I-E/C亚区编码的Ia同种异体抗原，并通过聚丙烯酰胺凝胶电泳分析结构变异。I-A亚区产物（k、d和B单倍型）由两种多肽α和β组成，具有m.w.分别是34,000和26,000道尔顿。单倍型相关的m.w.差异。在k、r、p和d单倍型的I-E/C产物中检测到。E/Ck和E/Cr的α和β链分别为34，000和28，000道尔顿; E/Cp和E/Cd分子由31，000和29，000道尔顿多肽组成。因此，存在亚区（I-A vs I-E/C）和单倍型（E/Ck，E/Cr vs E/Cd，E/Cp）相关的m.w.变异。Ia类同种异体抗原此外，检查了Ia亚基的共价与非共价缔合，发现I-A和I-E/C的α和β链都不是共价缔合的。然而，I-A α和β链在去污剂裂解过程中倾向于通过二硫键缔合;细胞裂解过程中存在烷化剂可阻止这种缔合，并且在非还原条件下仅观察到游离α和β链。
Murine splenocytes were radiolabeled with 3H- and 14C-amino acids; the Ia alloantigens encoded by the I-A and I-E/C subregions were isolated by immunoprecipitation and analyzed for structural variation by polyacrylamide gel electrophoresis. The I-A subregion products (k, d, and b haplotypes) are composed of two polypeptides, alpha and beta, with m.w. of 34,000 and 26,000 daltons, respectively. Haplotype-associated differences in m.w. were detected in the I-E/C products of the k, r, p, and d haplotypes. The alpha and beta chains of E/Ck and E/Cr are 34,000 and 28,000 daltons, respectively; E/Cp and E/Cd molecules are composed of 31,000 and 29,000 dalton polypeptides. Thus, there is both subregion (I-A vs I-E/C) and haplotype (E/Ck, E/Cr vs E/Cd, E/Cp) associated variation in the m.w. of the Ia alloantigens. Additionally, the covalent vs noncovalent association of the Ia subunits was examined and it was found that the alpha and beta chains of both I-A and I-E/C are not covalently associated. However, the I-A alpha and beta chains tend to associate through disulfide bonds during detergent lysis; the presence of alkylating agents during cell lysis prevents this association, and only free alpha and beta chains are observed under nonreducing conditions.