Subunit structure, cell surface orientation, and partial amino-acid sequences of murine histocompatibility antigens.
Subunit structure, cell surface orientation, and partial amino-acid sequences of murine histocompatibility antigens.
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鼠组织相容性抗原的亚基结构、细胞表面方向和部分氨基酸序列。
DOI：
10.1073/pnas.73.1.118
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发表时间：
1976
影响因子：
11.1
通讯作者：
Edelman
中科院分区：
文献类型：
--
作者：
Roland Henning;Robert J. Milner;Konrad Reske;Bruce A. Cunningham;M. Gerald;Edelman
洗涤剂和木瓜蛋白酶溶解小鼠组织相容性（H-2）抗原进行了比较，凝胶排阻色谱，超离心，十二烷基硫酸钠-聚丙烯酰胺凝胶电泳，和氨基酸序列分析。从这些数据中，我们提出了一个分子模型的H-2抗原，其中包括在细胞表面和溶液中的亚基的大小和排列，我们提供的证据，这些分子在细胞表面上的方向。去污剂溶解的H-2抗原（分子量116，000）由两条二硫键连接的重链（46，000道尔顿）和两条单共价结合的轻链（12，000道尔顿）组成。浸提前用碘乙酰胺进行烷基化可防止两条重链之间形成二硫键。通过木瓜蛋白酶消化细胞或去污剂提取物，获得由重链的39，000-道尔顿片段（FH）和一个完整轻链组成的水溶性51，000-道尔顿分子（Fs）。因此，重链之间的二硫键位于剩余的膜相关部分（Fm）。通过放射化学技术对H-2Kb的FH片段的氨基酸序列分析表明，对于所测试的三个氨基酸，其在八个位置与去污剂增溶的H-2Kb重链相同。这些数据表明，片段FH来自重链的氨基末端，并表明它从细胞表面向外突出，而羧基末端区域与质膜相关。已发现所述氨基末端序列数据在H-2Kb、H-2Kd、H-2Kk、H-2Db和H-2Dd基因产物中是恒定的。这些数据支持的假设，主要组织相容性抗原复合物的K和D产品已经演变的基因复制。
Detergent and papain solubilized murine histocompatibility (H-2) antigens have been compared by gel exclusion chromatography, ultracentrifugation, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and amino-acid sequence analysis. From these data, we propose a molecular model for the H-2 antigens that includes the size and arrangement of the subunits on the cell surface and in solution, and we provide evidence for the orientation of these molecules on the cell surface. Detergent solubilized H-2 antigens (molecular weight 116,000) consist of two disulfide-linked heavy chains (46,000 daltons) and two monocovalently associated light chains (12,000 daltons). Alkylation with iodoacetamide prior to extraction prevented the formation of a disulfide linkage between the two heavy chains. A water-soluble 51,000-dalton molecule (Fs) consisting of a 39,000-dalton fragment (FH) of the heavy chain and one intact light chain was obtained by papain digestion of cells or detergent extracts. Therefore, the disulfide linkage between the heavy chains is located in the remaining membrane-associated portion (Fm). Amino-acid sequence analysis of the FH fragment of H-2Kb by radiochemical techniques showed that it is identical to the detergent solubilized H-2Kb heavy chain in eight positions for the three amino acids tested. These data indicate that the fragment FH derives from the amino-terminus of the heavy chain and suggest that it projects outward from the cell surface, while the carboxyl-terminal region is associated with the plasma membrane. The described amino-terminal sequence data have been found constant in H-2Kb, H-2Kd, H-2Kk, H-2Db, and H-2Dd gene products. These data support the hypothesis that the K and D products of the major histocompatibility antigen complex have evolved by gene duplication.