COMPETITION FOR BINDING-SITES ON C3B BY CR-1, CR-2, MCP, FACTOR-B AND FACTOR-H

被引：40

作者：

FARRIES, TC ^{[1
]}

SEYA, T ^{[1
]}

HARRISON, RA ^{[1
]}

ATKINSON, JP ^{[1
]}

机构：

[1] WASHINGTON UNIV,SCH MED,HOWARD HUGHES MED INST LABS,ST LOUIS,MO 63110

来源：

COMPLEMENT AND INFLAMMATION | 1990年 / 7卷 / 01期

关键词：

C3b/C4b receptor or complement receptor type 1; C3b/C4b-binding proteins; C3d receptor or complement receptor type 2; Factor B; Factor H; Factor I; Formerly gp45-70; Membrane cofactor protein; Properdin;

D O I：

10.1159/000463124

中图分类号：

R392 [医学免疫学]; Q939.91 [免疫学];

学科分类号：

100102 ;

摘要：

The reaction of radiolabeled C3b-binding proteins with C3b-coated particles has been investigated. CR1 binding was inhibited by factor H and factor B (in the presence of properdin), but not by properdin alone. CR2 and MCP binding were also inhibited by factor H. Therefore factor H, factor B, CR1, CR2 and MCP probably comprise a group of mutually competitive proteins with similar or overlapping binding sites on C3b. These results correlate with their structural homology and suggest that they all evolved from a single C3b-binding molecule. Factor H, CR1 and MCP are also cofactors for the factor-I-mediated cleavage of C3b. A species incompatibility between rat factor I and human CR1 for the cleavage of human C3b suggests the possibility that cofactors may also function by interacting directly with factor I.

引用

页码：30 / 41

页数：12