Humphrey C D, Condon C W, Cantey J R, Pittman F E
Gastroenterology. 1979 Mar;76(3):468-76.
A toxin with cytotoxic and enterotoxic activities was isolated from cecal contents of hamsters receiving lincomycin. The toxin was partially purified by ultracentrifugation, ultrafiltration, (NH4)2SO4 precipitation, and gel filtration. Cytotoxic activity, assayed on monolayers of HeLa cells, was restricted to material that eluted in the molecular weight range of 107,000 +/- 6,000 daltons. Cytotoxicity of crude AAC toxin could be demonstrated at concentrations as low as 0.04 microgram/ml. The toxin was heat labile (55 degrees-60 degrees C for 0.5 hr) and sensitive to trypsinization, acidification at pH 3, or alkalinization at pH 9. Cytotoxic activity was inhibited by Clostridium sordellii antitoxin. Enterotoxic activity of the crude toxin and the cytotoxic fraction from gel filtration was demonstrated by fluid secretion in ligated rabbit ileal loops. Studies were done in vitro with cholestyramine resin, vancomycin, or gentamicin to determine if the toxin was bound or denatured by these drugs. It was demonstrated that cholestyramine bound the toxin, significantly reducing its cytotoxicity. Reversible binding of the cytotoxic material was demonstrated by salt gradient elution. Neither vancomycin nor gentamicin had any effect on the in vitro cytotoxic activity of the toxin.
从接受林可霉素的仓鼠盲肠内容物中分离出一种具有细胞毒性和肠毒性活性的毒素。该毒素通过超速离心、超滤、硫酸铵沉淀和凝胶过滤进行部分纯化。在HeLa细胞单层上测定的细胞毒性活性仅限于分子量范围为107,000±6,000道尔顿的洗脱物质。粗制AAC毒素的细胞毒性在低至0.04微克/毫升的浓度下即可显现。该毒素对热不稳定（55℃-60℃，0.5小时），对胰蛋白酶消化、pH 3酸化或pH 9碱化敏感。细胞毒性活性受到艰难梭菌抗毒素的抑制。通过结扎兔回肠袢中的液体分泌证明了粗毒素和凝胶过滤得到的细胞毒性部分的肠毒性活性。用消胆胺树脂、万古霉素或庆大霉素进行了体外研究，以确定该毒素是否被这些药物结合或变性。结果表明，消胆胺结合了毒素，显著降低了其细胞毒性。通过盐梯度洗脱证明了细胞毒性物质的可逆结合。万古霉素和庆大霉素对该毒素的体外细胞毒性活性均无任何影响。
