A PURIFIED GROUP A STREPTOCOCCAL PYROGENIC EXOTOXIN
A PURIFIED GROUP A STREPTOCOCCAL PYROGENIC EXOTOXIN
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纯化的A组链球菌热原性外毒素
DOI：
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发表时间：
1970
影响因子：
15.3
通讯作者：
D. W. Watson
中科院分区：
文献类型：
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作者：
Y. B. Kim;D. W. Watson
从A群链球菌滤液中纯化的热原外毒素（化脓性链球菌，10型，菌株NY-5）主要被表征为与透明质酸络合的蛋白质。氨基酸组成和分析显示一个典型的酸性蛋白质，平均分子量为29,000。纯化后的外毒素不含溶链酶O和S、烟酰胺腺嘌呤二核苷酸酶（nadase）、脱氧核糖核酸酶（dnase）、粘肽和内毒素。外毒素在65℃加热30 min或煮沸2 min时，生物活性被破坏。研究生物活性为家兔的热原性（最小热原剂量-3小时，0.07µg/kg）、家兔的致病性（LD 50, 3500µg/kg）、人皮肤的皮试剂量（> ~ 109皮试剂量，每mg毒素）、家兔脾巨噬细胞的细胞毒性（细胞毒性指数0.5 ~ 10µg/ml）、增强内毒素休克敏感性（>家兔10万倍）和抗原分析（a型毒素）。该外毒素具有免疫原性，因此有可能使动物免疫抵抗各种毒性活性。这种免疫是针对a型毒素的。这些外毒素的高度显著增强作用的临床意义进行了讨论。提示临床或亚临床感染A群链球菌可使宿主因革兰氏阴性感染或不慎注射少量革兰氏阴性细菌内毒素而发生致死性休克。
Purified pyrogenic exotoxin from Group A streptococcal filtrates (Streptococcus pyogenes, type 10, strain NY-5) has been characterized primarily as a protein complexed with hyaluronic acid. Amino acid composition and analysis revealed a typical acidic protein with an average molecular weight of 29,000. The purified exotoxin was free of streptolysins O and S, nicotinamide adenine dinucleotidases (NADases), deoxyribonucleases (DNases), mucopeptide, and endotoxins. The biological activity was destroyed when the exotoxin was heated at 65°C for 30 min or boiled for 2 min. The biological activities investigated were pyrogenicity in rabbits (minimal pyrogenic dose-3 hr, 0.07 µg/kg), lethality in rabbits (LD 50, 3500 µg/kg), skin test dose in human skin (> 109 skin test doses, per mg toxin), cytotoxicity of rabbit spleen macrophage (Cytotoxic Index 0.5–10 µg/ml), enhancement of susceptibility to endotoxin shock (in rabbits > 100,000-fold), and antigenic analysis (A-type toxin). The exotoxin was immunogenic and it was possible, therefore, to immunize animals against the various toxic activities. The immunity was specific for the A-type toxin. The clinical implications of the highly significant enhancement effect of these exotoxins are discussed. It is suggested that clinical or subclinical infection with Group A streptococci could prepare the host for fatal shock from Gram-negative infections or the inadvertent injection of small amounts of Gram-negative bacterial endotoxins.