Kawabata S, Miyata T, Morita T, Miyata T, Iwanaga S, Igarashi H
J Biol Chem. 1986 Jan 15;261(2):527-31.
The primary structure of the procoagulant- and prothrombin-binding domains, the 43- and 30-kDa fragments previously isolated from staphylocoagulase, has been determined by sequencing peptides derived from various chemical (CNBr and 2-(2-nitrophenylsulfenyl)-3-methyl-3-bromoindolenine) and enzymatic (trypsin and alpha-chymotrypsin) cleavages. Carboxypeptidase Y was also used to deduce the COOH-terminal sequence. The 43-kDa fragment contained 324 amino acids and had a calculated molecular weight of 38,098. It included the entire structure of the 30-kDa fragment located in the COOH-terminal portion (positions 126-324). The 43-kDa fragment had an unusual amino acid composition based on the sequence, in which the sum of Asp (28 residues), Asn (22), Glu (35), Gln (9), and Lys (52) residues accounted for more than 45% of the total. In addition, the frequent occurrence of repetitions of the various kinds of dipeptides was found along the whole sequence. Structural comparison of the NH2-terminal portion of the 43-kDa fragment of staphylocoagulase with that of streptokinase did not reveal any obvious sequence homologies. There was also no sequence homology with that of trypsin, alpha-chymotrypsin, and elastase.
促凝血酶原和凝血酶结合结构域的一级结构，即先前从葡萄球菌凝固酶中分离出的43 kDa和30 kDa片段，已通过对源自各种化学（溴化氰和2-(2-硝基苯磺酰基)-3-甲基-3-溴吲哚）和酶促（胰蛋白酶和α-糜蛋白酶）裂解产生的肽段进行测序来确定。羧肽酶Y也被用于推导COOH末端序列。43 kDa片段包含324个氨基酸，计算分子量为38,098。它包括位于COOH末端部分（第126 - 324位）的30 kDa片段的完整结构。根据序列，43 kDa片段具有不寻常的氨基酸组成，其中天冬氨酸（28个残基）、天冬酰胺（22个）、谷氨酸（35个）、谷氨酰胺（9个）和赖氨酸（52个）残基的总和占总数的45%以上。此外，在整个序列中发现了各种二肽重复的频繁出现。葡萄球菌凝固酶43 kDa片段的NH2末端部分与链激酶的NH2末端部分的结构比较未发现任何明显的序列同源性。与胰蛋白酶、α-糜蛋白酶和弹性蛋白酶也没有序列同源性。
