Rosin M P, Stich H F
Cancer Res. 1978 May;38(5):1307-10.
The effect of cysteine (alpha-amino-beta-mercaptopropionic acid) on the mutagenic activities of the proximate carcinogen, N-hydroxy-2-acetylaminofluorene, and the ultimate carcinogen, N-acetoxy-2-acetylaminofluorene, was examined by estimating the frequency of his+ revertants of Salmonella typhimurium. Nontoxic concentrations of cysteine significantly reduced the formation of revertants when it was applied concurrently with the two carcinogens. Cysteine showed no detectable effect on mutagenesis when added to bacteria before or after exposure to carcinogens. The magnitude of inhibition of mutagenesis depended on the dose of cysteine and the concentration of the carcinogens. Cysteine at equimolar concentrations inhibited to a larger degree the mutagenesis induced by N-hydroxy-2-acetylaminofluorene than it inhibited that elicited by N-acetoxy-2-acetylaminofluorene. The inhibitory action of cysteamine and glutathione was comparable to that of cysteine. The results appear to be consistent with the assumption that cysteine traps electrophiles prior to their action on DNA.
通过估算鼠伤寒沙门氏菌 his+回复突变体的频率，研究了半胱氨酸（α-氨基-β-巯基丙酸）对近端致癌物 N-羟基-2-乙酰氨基芴和最终致癌物 N-乙酰氧基-2-乙酰氨基芴诱变活性的影响。当半胱氨酸与两种致癌物同时使用时，无毒浓度的半胱氨酸显著降低了回复突变体的形成。在接触致癌物之前或之后向细菌中添加半胱氨酸，未显示出对半诱变作用的可检测影响。诱变抑制的程度取决于半胱氨酸的剂量和致癌物的浓度。等摩尔浓度的半胱氨酸对 N-羟基-2-乙酰氨基芴诱导的诱变的抑制程度大于对 N-乙酰氧基-2-乙酰氨基芴诱导的诱变的抑制程度。半胱胺和谷胱甘肽的抑制作用与半胱氨酸相当。结果似乎与半胱氨酸在亲电试剂作用于 DNA 之前捕获它们的假设一致。
