Christie D L, Gagnon J
Biochem J. 1983 Jan 1;209(1):61-70. doi: 10.1042/bj2090061.
The amino acid sequence of peptide CB-II, the major product (mol.wt. 30 000) of CNBr cleavage of fragment Bb from human complement Factor B, is given. The sequence was obtained from peptides derived by trypsin cleavage of peptide CB-II and clostripain digestion of fragment Bb. Cleavage of two Asn-Gly bonds in peptide CB-II was also found useful. These results, along with those presented in the preceding paper [Gagnon & Christie (1983) Biochem. J. 209, 51-60], yield the complete sequence of the 505 amino acid residues of fragment Bb. The C-terminal half of the molecule shows strong homology of sequence with serine proteinases. Factor B has a catalytic chain (fragment Bb) with a molecular weight twice that of proteinases previously described, suggesting that it is a novel type of serine proteinase, probably with a different activation mechanism.
给出了人补体因子B的Bb片段经溴化氰裂解后的主要产物（分子量30000）肽CB-II的氨基酸序列。该序列是从经胰蛋白酶裂解肽CB-II和经梭菌蛋白酶消化Bb片段得到的肽段中获得的。还发现裂解肽CB-II中的两个天冬酰胺-甘氨酸键很有用。这些结果与前文[加尼翁和克里斯蒂（1983年）《生物化学杂志》209卷，51 - 60页]所呈现的结果一起，得出了Bb片段505个氨基酸残基的完整序列。该分子的C端一半显示出与丝氨酸蛋白酶有很强的序列同源性。因子B有一条催化链（Bb片段），其分子量是先前描述的蛋白酶的两倍，这表明它是一种新型的丝氨酸蛋白酶，可能具有不同的激活机制。
