Sjöholm A G, Laurell A B
Clin Exp Immunol. 1973 Aug;14(4):515-29.
C4 in EDTA plasma and partially purified C4 give a β peak on crossed immunoelectrophoresis. During electrophoresis C4 in serum is converted to a product of fast β mobility, usually accompanied by a slow β peak. Conversion in serum is inhibited by EDTA. Storage of serum at room temperature results in a gradual increase of the slow β peak. Storage of EDTA plasma changes the configuration of the native β peak. C[unk]s, trypsin, chymotrypsin, plasmin or thrombin added to partially purified C4 is capable of producing a fast β C4 protein peak. C[unk]s, trypsin and chymotrypsin give this conversion product also when added to EDTA serum. C[unk]s, trypsin and chymotrypsin also give rise to a show β and an inter α C4 conversion product in serum, probably consisting of complex formations between C4 and other serum proteins. Enzyme inhibitors known to interfere with C[unk] inhibit the conversion of C4 in serum on agarose electrophoresis. The results suggest that such conversion is caused by an activation of C1 during electrophoresis.
乙二胺四乙酸（EDTA）血浆中的C4和部分纯化的C4在交叉免疫电泳中呈现β峰。在电泳过程中，血清中的C4会转化为具有快速β迁移率的产物，通常伴有一个缓慢的β峰。血清中的这种转化受到EDTA的抑制。血清在室温下储存会导致缓慢β峰逐渐增加。EDTA血浆的储存会改变天然β峰的构型。添加到部分纯化的C4中的C[unk]s、胰蛋白酶、糜蛋白酶、纤溶酶或凝血酶能够产生快速β C4蛋白峰。当添加到EDTA血清中时，C[unk]s、胰蛋白酶和糜蛋白酶也会产生这种转化产物。C[unk]s、胰蛋白酶和糜蛋白酶在血清中还会产生一个缓慢的β峰和一个中间α C4转化产物，可能是由C4与其他血清蛋白之间的复合物形成所致。已知干扰C[unk]的酶抑制剂会抑制琼脂糖电泳中血清中C4的转化。结果表明，这种转化是由电泳过程中C1的激活引起的。
