Matsushita O, Yoshihara K, Katayama S, Minami J, Okabe A
Department of Microbiology, Kagawa Medical School, Japan.
J Bacteriol. 1994 Jan;176(1):149-56. doi: 10.1128/jb.176.1.149-156.1994.
Clostridium perfringens type C NCIB 10662 produced various gelatinolytic enzymes with molecular masses ranging from approximately 120 to approximately 80 kDa. A 120-kDa gelatinolytic enzyme was present in the largest quantity in the culture supernatant, and this enzyme was purified to homogeneity on the basis of sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purified enzyme was identified as the major collagenase of the organism, and it cleaved typical collagenase substrates such as azocoll, a synthetic substrate (4-phenylazobenzyloxy-carbonyl-Pro-Leu-Gly-Pro-D-Arg [Pz peptide]), and a type I collagen fibril. In addition, a gene (colA) encoding a 120-kDa collagenase was cloned in Escherichia coli. Nested deletions were used to define the coding region of colA, and this region was sequenced; from the nucleotide sequence, this gene encodes a protein of 1,104 amino acids (M(r), 125,966). Furthermore, from the N-terminal amino acid sequence of the purified enzyme which was found in this reading frame, the molecular mass of the mature enzyme was calculated to be 116,339 Da. Analysis of the primary structure of the gene product showed that the enzyme was produced with a stretch of 86 amino acids containing a putative signal sequence. Within this stretch was found PLGP, the amino acid sequence constituting the Pz peptide. This sequence may be implicated in self-processing of the collagenase. A consensus zinc-binding sequence (HEXXH) suggested for vertebrate Zn collagenases is present in this bacterial collagenase. Vibrio alginolyticus collagenase and Achromobacter lyticus protease I showed significant homology with the 120-kDa collagenase of C. perfringens, suggesting that these three enzymes are evolutionarily related.
产气荚膜梭菌C型NCIB 10662产生了多种明胶水解酶,其分子量范围约为120至约80 kDa。一种120 kDa的明胶水解酶在培养上清液中含量最高,并且基于十二烷基硫酸钠 - 聚丙烯酰胺凝胶电泳将该酶纯化至同质。纯化后的酶被鉴定为该生物体的主要胶原酶,它能切割典型的胶原酶底物,如偶氮胶原、一种合成底物(4 - 苯基偶氮苄氧基 - 羰基 - 脯氨酸 - 亮氨酸 - 甘氨酸 - 脯氨酸 - D - 精氨酸[Pz肽])和I型胶原纤维。此外,编码120 kDa胶原酶的基因(colA)在大肠杆菌中被克隆。采用嵌套缺失法确定colA的编码区,并对该区域进行测序;从核苷酸序列来看,该基因编码一个1104个氨基酸的蛋白质(分子量,125,966)。此外,根据在此阅读框中发现的纯化酶的N端氨基酸序列,计算出成熟酶的分子量为116,339 Da。对基因产物一级结构的分析表明,该酶产生时带有一段包含推定信号序列的86个氨基酸。在这段序列中发现了构成Pz肽的氨基酸序列PLGP。该序列可能与胶原酶的自我加工有关。在这种细菌胶原酶中存在脊椎动物锌胶原酶所建议的共有锌结合序列(HEXXH)。溶藻弧菌胶原酶和溶杆菌蛋白酶I与产气荚膜梭菌的120 kDa胶原酶显示出显著的同源性,表明这三种酶在进化上相关。