Moks T, Abrahmsén L, Nilsson B, Hellman U, Sjöquist J, Uhlén M
Eur J Biochem. 1986 May 2;156(3):637-43. doi: 10.1111/j.1432-1033.1986.tb09625.x.
A genetic approach is described to clarify the IgG-binding properties of the N-terminal portion of staphylococcal protein A (region E). Several gene fragments, encoding region E or B or protein A, have been cloned and expressed in Escherichia coli. The gene products were purified by IgG-affinity chromatography and subjected to structural and functional analyses. Both fragments can be efficiently purified using this method, suggesting that region B as well as region E has Fc-binding activity. In addition, gene fusions were assembled giving fragments EB and EE, which both showed a divalent Fc-binding. These results demonstrate that protein A consists of five IgG-binding domains. The implications of these findings for the structure of protein-A--immunoglobulin-G complexes are discussed.
本文描述了一种遗传学方法，以阐明葡萄球菌蛋白A（区域E）N端部分的IgG结合特性。几个编码区域E、B或蛋白A的基因片段已被克隆并在大肠杆菌中表达。基因产物通过IgG亲和层析纯化，并进行结构和功能分析。使用该方法可有效纯化这两个片段，表明区域B以及区域E都具有Fc结合活性。此外，构建了基因融合体，得到片段EB和EE，二者均表现出二价Fc结合。这些结果证明蛋白A由五个IgG结合结构域组成。讨论了这些发现对蛋白A-免疫球蛋白G复合物结构的影响。
