Heath D G, Boyle M D, Cleary P P
Department of Microbiology, University of Minnesota, Minneapolis 55455.
Mol Microbiol. 1990 Dec;4(12):2071-9. doi: 10.1111/j.1365-2958.1990.tb00567.x.
The DNA repeat region of fcrA76, the gene encoding a group A streptococcal Fc-binding protein, was subcloned in-frame into an Escherichia coli plasmid expression vector. The expressed protein product displayed the same Fc-binding properties as the full-length Fc-binding protein expressed from fcrA76. The affinity-purified, full-length Fc-binding protein was found to compete with staphylococcal protein A or streptococcal protein G for binding to beads coated with human IgG. These results are consistent with earlier studies suggesting that the binding sites on human IgG for protein A, protein G and the type II Fc-binding protein from group A streptococci are located at the interface of the CH2 and CH3 domains of the Fc region.
编码A组链球菌Fc结合蛋白的基因fcrA76的DNA重复区域被框内亚克隆到大肠杆菌质粒表达载体中。表达的蛋白质产物表现出与从fcrA76表达的全长Fc结合蛋白相同的Fc结合特性。发现亲和纯化的全长Fc结合蛋白与葡萄球菌蛋白A或链球菌蛋白G竞争结合包被有人IgG的珠子。这些结果与早期研究一致，表明人IgG上与蛋白A、蛋白G和A组链球菌II型Fc结合蛋白的结合位点位于Fc区域CH2和CH3结构域的界面处。
