II'o 型 A 组链球菌免疫球蛋白结合蛋白的特性分析

Characterization of a type II'o group A streptococcal immunoglobulin-binding protein.

作者信息

Pack T D, Boyle M D

机构信息

Department of Microbiology, Medical College of Ohio, Toledo 43699-0008, USA.

出版信息

Mol Immunol. 1995 Nov;32(16):1235-43. doi: 10.1016/0161-5890(95)00074-7.

DOI:10.1016/0161-5890(95)00074-7

PMID:8559148

Abstract

The opacity factor positive M type 2 group A streptococcal isolate, A207, expresses a unique functional type II'o IgG-binding protein which reacts with all four human IgG subclasses and rabbit IgG. In order to determine the gene product or products responsible for this activity, three genes of the vir regulon from this isolate were cloned, expressed and analysed. The fcr A2 gene coded for a protein binding hyman IgG1, IgG2 and IgG4 but not IgG3. The enn2 gene coded for a protein reacting exclusively with human IgA, while the emmL2 gene product bound IgG1, IgG2, IgG3 and IgG4 as well as rabbit but not horse or pig IgG. The IgG3-binding activity of the EmmL2 protein was functionally indistinguishable from the Form 1 IgG3-binding activity present in heat extracts of group A isolate A207.

摘要

不透明因子阳性M型2组A链球菌分离株A207表达一种独特的功能性II'o型IgG结合蛋白，该蛋白可与所有四种人类IgG亚类以及兔IgG发生反应。为了确定负责此活性的一种或多种基因产物，对该分离株的vir调控子的三个基因进行了克隆、表达和分析。fcr A2基因编码一种结合人类IgG1、IgG2和IgG4但不结合IgG3的蛋白质。enn2基因编码一种仅与人IgA反应的蛋白质，而emmL2基因产物结合IgG1、IgG2、IgG3和IgG4以及兔IgG，但不结合马或猪IgG。EmmL2蛋白的IgG3结合活性在功能上与A组分离株A207热提取物中存在的形式1 IgG3结合活性无法区分。