Sim R B, DiScipio R G
Biochem J. 1982 Aug 1;205(2):285-93. doi: 10.1042/bj2050285.
An efficient procedure for the isolation of the complement-system control protein beta 1H (Factor H) from human plasma was developed. The chemical composition and physical characteristics of the protein were studied, and a sequence of 17 amino acid residues at the N-terminus was determined. Factor H is a single-polypeptide-chain glycoprotein of mol.wt. 155 000 containing 9.3% carbohydrate. Factor H is cleaved by plasma proteinases to a two-chain form. This cleavage can be mimicked by trypsin, and the two-chain form retains fully the C3b-inactivator cofactor activity of Factor H. The proteolytic fragments of Factor H are compared with those of other proteins (C4b-binding protein and erythrocyte C3b-receptor) that act as cofactors for C3b-inactivator.
已开发出一种从人血浆中分离补体系统调控蛋白β1H（H因子）的有效方法。对该蛋白的化学组成和物理特性进行了研究，并确定了其N端17个氨基酸残基的序列。H因子是一种单链糖蛋白，分子量为155000，含9.3%的碳水化合物。H因子被血浆蛋白酶裂解为双链形式。胰蛋白酶可模拟这种裂解，且双链形式完全保留H因子的C3b灭活剂辅因子活性。将H因子的蛋白水解片段与其他作为C3b灭活剂辅因子的蛋白（C4b结合蛋白和红细胞C3b受体）的片段进行了比较。
