Harris C L
Nucleic Acids Res. 1978 Feb;5(2):599-613. doi: 10.1093/nar/5.2.599.
Transfer RNA sulfurtransferase activity was detected in 105,000 x g supernatant preparations from rat liver and several other rat tissues. Sulfur is transferred from [35S] cysteine to tRNA in a reaction which also requires ATP, Mg2+, and supernatant protein. While [35S] beta-mercaptopyruvate appeared to be a substrate for this enzyme, the reaction product was sensitive to deacylation and the reaction was inhibited by [32S] cysteine. Of the various nucleic acids tested, only tRNAs were effective sulfur acceptors, with rat liver tRNA being the poorest substrate. The [35S] reaction product was sensitive to ribonuclease, cochromatographed with tRNA on methylated-albumin kieselguhr columns, and was converted to nucleotide material after alkaline hydrolysis. DEAE-cellulose chromatography of the neutralized [35S] nucleotide digest revealed a single thionucleotide peak. These studies demonstrate that tRNA sulfurtransferase is present in various rat tissues, and that the requirements of the liver enzyme are similar to those of bacterial enzymes.
在大鼠肝脏及其他几种大鼠组织的105,000 x g 上清液制剂中检测到了转移RNA硫转移酶活性。硫在一种反应中从[35S]半胱氨酸转移至tRNA,该反应还需要ATP、Mg2+和上清液蛋白。虽然[35S]β-巯基丙酮酸似乎是该酶的一种底物,但反应产物对脱酰作用敏感,且该反应受到[32S]半胱氨酸的抑制。在测试的各种核酸中,只有tRNA是有效的硫受体,大鼠肝脏tRNA是最差的底物。[35S]反应产物对核糖核酸酶敏感,在甲基化白蛋白硅藻土柱上与tRNA共层析,并在碱性水解后转化为核苷酸物质。对中和后的[35S]核苷酸消化物进行DEAE-纤维素层析显示出一个单一的硫代核苷酸峰。这些研究表明,tRNA硫转移酶存在于各种大鼠组织中,且肝脏酶的需求与细菌酶的需求相似。