葡萄球菌蛋白A与人类IgG亚类及同种异型

Staphylococcal protein A and human IgG subclasses and allotypes.

作者信息

Van Loghem E, Frangione B, Recht B, Franklin E C

出版信息

Scand J Immunol. 1982 Mar;15(3):275-8. doi: 10.1111/j.1365-3083.1982.tb00649.x.

DOI:10.1111/j.1365-3083.1982.tb00649.x

Abstract

Staphylococcal protein A binds molecules belonging to the IgG1, IgG2, and IgG4 subclasses. IgG3 proteins generally do not bind, except for those coded by the two gamma 3 alleles, which are G3m(u-): G3m(b0,b3,b5,s,v). G3m(u) is located in the CH2 domain. The difference between G3m(u-) and G3m(u+) IgG3 proteins correlates with the sequence at position 339 in the CH2 domain--Ala and Thr respectively. There is another structural difference in the CH3 domain which correlates with protein A binding and non-binding: all IgG proteins that bind protein A have His at position 435, whereas those that do not, have Arg at that position.

摘要

葡萄球菌蛋白A可结合属于IgG1、IgG2和IgG4亚类的分子。IgG3蛋白通常不结合，但由两个γ3等位基因编码的除外，这两个等位基因是G3m(u-)：G3m(b0,b3,b5,s,v)。G3m(u)位于CH2结构域。G3m(u-)和G3m(u+) IgG3蛋白之间的差异与CH2结构域中第339位的序列相关，分别为丙氨酸和苏氨酸。CH3结构域中还有另一个与蛋白A结合和不结合相关的结构差异：所有结合蛋白A的IgG蛋白在第435位都有组氨酸，而不结合的则在该位置有精氨酸。