化脓性链球菌碱性超抗原（SPEX/SMEZ3）的纯化及生化特性分析

Purification and biochemical characterization of a basic superantigen (SPEX/SMEZ3) from Streptococcus pyogenes.

作者信息

Gerlach D, Fleischer B, Wagner M, Schmidt K, Vettermann S, Reichardt W

机构信息

Institute of Medical Microbiology, Friedrich-Schiller-University Jena, Semmelweisstr, Jena, Germany.

出版信息

FEMS Microbiol Lett. 2000 Jul 15;188(2):153-63. doi: 10.1111/j.1574-6968.2000.tb09187.x.

DOI:10.1111/j.1574-6968.2000.tb09187.x

PMID:10913699

Abstract

A potent basic superantigen (designated streptococcal pyrogenic exotoxin X, SPEX/SMEZ3) was purified to homogeneity from culture supernatants of a Streptococcus pyogenes scarlatina strain of type 12 (genotype speA(-), speC(-)) and characterized. Sequence alignments revealed SPEX to be an allele of the streptococcal mitogens type Z (SMEZ). The N-terminal amino acid sequence of SPEX was found with LEVDNNSLLR to be identical to the recently described acidic superantigen SMEZ. Although SPEX/SMEZ genes were present in all of the streptococcal strains tested, a toxin production could only be detected in a small number of strains. The produced toxin concentration in the culture supernatants of positive strains differed between 0 and 20 ng ml(-1). The purified SPEX stimulated human T-lymphocytes with Vbeta8 specificity at extremely low concentrations (lower than 100 pg ml(-1)).

摘要

从12型化脓性链球菌猩红热菌株（基因型speA(-)，speC(-)）的培养上清液中纯化出一种强效碱性超抗原（命名为化脓性链球菌热原性外毒素X，SPEX/SMEZ3）并进行了表征。序列比对显示SPEX是Z型链球菌丝裂原（SMEZ）的一个等位基因。发现SPEX的N端氨基酸序列LEVDNNSLLR与最近描述的酸性超抗原SMEZ相同。尽管在所有测试的链球菌菌株中都存在SPEX/SMEZ基因，但仅在少数菌株中检测到毒素产生。阳性菌株培养上清液中产生的毒素浓度在0至20 ng ml(-1)之间。纯化的SPEX在极低浓度（低于100 pg ml(-1)）下刺激具有Vbeta8特异性的人T淋巴细胞。