Investigations of the complement-fixing sites of immunoglobulins.
Investigations of the complement-fixing sites of immunoglobulins.
复制标题
免疫球蛋白补体固定位点的研究。
作者：
B. Johnson;K. Thames
通过对免疫球蛋白的化学修饰，已经发现了人免疫球蛋白补体结合部位的间接证据。这些结果涉及氨基酸残基、色氨酸、酪氨酸和精氨酸。此外，通过合成肽的使用，已经表明，位于277和278位的色氨酸和酪氨酸周围的区域可能构成了人IgG1的补体结合位点的位置。以此类推，人类IgM第488位的色氨酸与这种免疫球蛋白的补体固定部位有关。这一点的证据是一种模拟人类IgM序列487-491的肽，它具有消耗补体的能力。这种多肽的相对补体固定能力比人的IgG1低200倍。
Indirect evidence for the complement-fixing site of human IgG1 has been found by using chemical modification of the immunoglobulin. These results implicate the amino acid residues, tryptophan, tyrosine, and arginine. Furthermore, by the use of synthetic peptides it has been shown that the area surrounding the tryptophan and tyrosine at positions 277 and 278 probably constitutes the locus of the complement-fixing site of human IgG1. By analogy, the tryptophan at position 488 of human IgM is implicated in the complement-fixing site of this immunoglobulin. Evidence for this is presented by a peptide which mimics the sequence 487-491 of human IgM and possesses the ability to consume complement. The relative complement-fixing ability of this peptide is 200 times less effective than human IgG1.