Dissociation and exchange of the beta 2-microglobulin subunit of HLA-A and HLA-B antigens.
Dissociation and exchange of the beta 2-microglobulin subunit of HLA-A and HLA-B antigens.
复制标题
HLA-A 和 HLA-B 抗原的 β2-微球蛋白亚基的解离和交换。
DOI：
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发表时间：
1979
影响因子：
11.1
通讯作者：
J. Strominger
中科院分区：
文献类型：
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作者：
F. Hyafil;J. Strominger
人类组织相容性抗原HLA-A、HLA-B和HLA-C是两个非共价结合的亚基的复合物：携带遗传多态性的重链糖蛋白（α）和不变的轻链β 2-微球蛋白（β 2 m）。在木瓜蛋白酶溶解的HLA与放射性标记的尿β 2 m孵育后，后者被掺入HLA中，在那里它取代了已经从复合物中解离的预先存在的β 2 m。研究了支配该β 2 m交换反应的缔合-解离平衡，发现其特征在于复合物的长寿命（在37 ° C下的半衰期为80分钟）和相对低的Kd（4 nM）。β 2 m交换用作HLA抗原放射免疫测定的基础，放射性标记的β 2 m作为所有HLA特异性的唯一标记。以类似的方式，放射性标记的β 2 m可以在细胞表面掺入HLA中。虽然这一过程比溶液中的过程更慢，也更不广泛，但它可以用作一种用HLA抗原的特异性探针标记细胞的方法。
Human histocompatibility antigens HLA-A, HLA-B, and HLA-C are a complex of two noncovalently associated subunits: a heavy chain glycoprotein (alpha) carrying the genetic polymorphism and an invariant light chain, beta 2-microglobulin (beta 2m). Upon incubation of papain-solubilized HLA with radiolabeled urinary beta 2m, the latter is incorporated into HLA, where it substitutes for the preexisting beta 2m that has dissociated from the complex. The association-dissociation equilibrium that governs this beta 2m exchange reaction was investigated and found to be characterized by a long lifetime of the complex (half-life of 80 min at 37 degrees C) and a relatively low Kd (4 nM). The beta 2m exchange was used as the basis of a radioimmunoassay for HLA antigens with radiolabeled beta 2m as a unique label for all HLA specificities. In a similar fashion, radiolabeled beta 2m can be incorporated into HLA at the cell surface. Although the process is slower and less extensive than in solution, it can be used as a means to tag cells with specific probes for HLA antigens.