Volanakis J E, Bhown A, Bennett J C, Mole J E
Proc Natl Acad Sci U S A. 1980 Feb;77(2):1116-9. doi: 10.1073/pnas.77.2.1116.
Human factor D purified to homogeneity by a modified procedure was subjected to NH2-terminal amino acid sequence analysis by using a modified automated Beckman sequencer. We identified 48 of the first 57 NH2-terminal amino acids in a single sequencer run, using microgram quantities of factor D. The deduced amino acid sequence represents approximately 25% of the primary structure of factor D. This extended NH2-terminal amino acid sequence of factor D was compared to that of other trypsin-related serine proteases. By visual inspection, strong homologies (33--50% identity) were observed with all the serine proteases included in the comparison. Interestingly, factor D showed a higher degree of homology to serine proteases of pancreatic origin than to those of serum origin.
采用改良方法纯化至同质的人因子D，通过使用改良的自动贝克曼测序仪进行N端氨基酸序列分析。我们使用微克量的因子D，在单次测序运行中鉴定出了前57个N端氨基酸中的48个。推导的氨基酸序列约占因子D一级结构的25%。将因子D的这个延长的N端氨基酸序列与其他胰蛋白酶相关丝氨酸蛋白酶的序列进行了比较。通过目视检查，发现与比较中包含的所有丝氨酸蛋白酶有很强的同源性（同一性为33%-50%）。有趣的是，因子D与胰腺来源的丝氨酸蛋白酶的同源性高于与血清来源的丝氨酸蛋白酶的同源性。
