Nilsson T, Wiman B
Biochim Biophys Acta. 1982 Jul 26;705(2):271-6. doi: 10.1016/0167-4838(82)90188-1.
A new purification method for C1-esterase inhibitor is described, which is essentially a three-step procedure: precipitation with poly(ethylene glycol), chromatography on DEAE-cellulose and hydrophobic interaction chromatography on hexyl-Sepharose. The final product is a single-chain glycoprotein with a molecular weight of about 100 000 and NH2-terminal asparagine. The molecule is fully active as judged by complex formation with C1s. Two of its three disulphide bridges can be easily reduced and S-carboxymethylated under non-denaturing conditions without loss of activity. However, at high dithioerythritol concentration the third disulphide bridge is also cleaved and accompanied by loss of the activity, indicating that this disulphide bridge is involved in maintaining the conformation around the reactive site in the inhibitor.
本文描述了一种新的C1酯酶抑制剂纯化方法，该方法主要包括三个步骤：用聚乙二醇沉淀、在DEAE-纤维素上进行层析以及在己基琼脂糖上进行疏水相互作用层析。最终产物是一种单链糖蛋白，分子量约为100000，氨基末端为天冬酰胺。根据与C1s形成复合物的情况判断，该分子具有完全活性。在非变性条件下，其三个二硫键中的两个可以很容易地被还原并进行S-羧甲基化，而不会丧失活性。然而，在高浓度二硫苏糖醇的情况下，第三个二硫键也会被切断，并伴随着活性丧失，这表明该二硫键参与维持抑制剂活性位点周围的构象。
