Ferreira A, Nussenzweig V
J Immunol. 1979 Feb;122(2):490-3.
We report here that a large fragment of mouse C4 (C4c) can be easily purified from serum with good recoveries, and used to produce a monospecific antiserum. The method of isolation of C4c is based on the observation that C4 is easily activated and fragmented in mouse serum. The fragments bind to the C4-binding protein (C4-bp), a newly described macromolecular component of the complement system. The high m.w. complexes were precipitated by dialysis of the serum against 0.1 M acetate buffer, pH 5.0, and purified by passage of the dissolved precipitate through a Sephadex G-200 column. The complexes were dissociated at high salt concentration, and the C4 fragments were isolated by passage of the mixture through a second Sephadex G-200 column. One of the C4 fragments (C4c) was used to immunize rabbits, and a monospecific antiserum was obtained, which showed a reaction of identity between C4 and Slp. Therefore the C4c fragment of C4 and the Slp protein are structurally related.
我们在此报告，小鼠C4的一个大片段（C4c）可轻松从血清中纯化出来，回收率良好，并用于制备单特异性抗血清。C4c的分离方法基于以下观察结果：C4在小鼠血清中易于激活和裂解。这些片段与补体系统新描述的大分子成分C4结合蛋白（C4-bp）结合。通过将血清对0.1 M乙酸盐缓冲液（pH 5.0）进行透析沉淀出高分子量复合物，并通过将溶解的沉淀物通过Sephadex G-200柱进行纯化。复合物在高盐浓度下解离，通过将混合物通过第二个Sephadex G-200柱分离出C4片段。其中一个C4片段（C4c）用于免疫兔子，获得了单特异性抗血清，该抗血清显示C4和Slp之间存在同一性反应。因此，C4的C4c片段与Slp蛋白在结构上相关。
