Secretion of Hemolysin of Aeromonas sobria as Protoxin and Contribution of the Propeptide Region Removed from the Protoxin to the Proteolytic Stability of the Toxin
Secretion of Hemolysin of Aeromonas sobria as Protoxin and Contribution of the Propeptide Region Removed from the Protoxin to the Proteolytic Stability of the Toxin
复制标题
温和气单胞菌溶血素作为原毒素的分泌及原毒素去除的前肽区域对毒素蛋白水解稳定性的贡献
DOI：
10.1111/j.1348-0421.1999.tb02369.x
复制
发表时间：
1999
影响因子：
2.6
通讯作者：
K. Okamoto
中科院分区：
文献类型：
--
作者：
T. Nomura;Y. Fujii;K. Okamoto
温和气单胞菌溶血素氨基端序列与A.你好然而，在羧基末端区域的序列中，两种毒素之间没有同源性。已经表明气溶素作为原毒素分泌到培养上清液中。这种气溶素原通过羧基末端肽的蛋白水解去除而被激活。然而，在激活过程中被去除的羧基末端区域的作用尚未阐明。在这项研究中，我们发现溶血素也作为原毒素分泌到培养上清液中，并且溶血素原被A. sobria在Ser-446和Ala-447之间，导致去除42个氨基酸的肽。肽的去除将原溶血素转化为活性溶血素。随后，我们突变溶血素基因，删除最后几个氨基酸残基，并在大肠杆菌中表达的基因，以检查前溶血素的羧基末端区域的作用。这些突变溶血素在E.大肠杆菌中的表达量与野生型相比非常低。这一观察结果表明，溶血素原的羧基末端区域有助于毒素的蛋白水解稳定性。
The sequence at the amino terminus region of the hemolysin of Aeromonas sobria is homologous with that of aerolysin of A. hydrophila. However, there is no homology between the two toxins in the sequence at the carboxy terminal region. It has been shown that aerolysin is secreted into culture supernatant as a protoxin. This proaerolysin is activated by the proteolytic removal of a carboxy terminal peptide. However, the role of the carboxy terminal region, which is removed in the activation process, has not been elucidated. In this study, we showed that hemolysin is also secreted as a protoxin into culture supernatant and that prohemolysin is cleaved by the protease of A. sobria between Ser‐446 and Ala‐447, resulting in the removal of a 42 amino acid peptide. The removal of the peptide converts the prohemolysin into active hemolysin. Subsequently, we mutated the hemolysin gene to delete the last several amino acid residues and expressed the genes in Escherichia coli, in order to examine the role of the carboxy terminal region of prohemolysin. The amounts of these mutant hemolysins accumulated in the periplasmic space of E. coli were very low compared with that of the wild‐type. This observation indicated that the carboxy terminal region of prohemolysin contributes to the proteolytic stability of the toxin.
DOI：
10.1016/s0021-9258(18)52979-3
发表时间：
1993-04
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
A. Loewy;U. Santer;M. Wieczorek;J. K. Blodgett;S. Jones;J. Cheronis
通讯作者：
A. Loewy;U. Santer;M. Wieczorek;J. K. Blodgett;S. Jones;J. Cheronis