Glick J M, Leboy P S
J Biol Chem. 1977 Jul 25;252(14):4790-5.
An S-adenosylmethionine-dependent tRNA(adenine-1)-methyltransferase has been purified 8,000-fold from rat liver. This preparation gives a single band on polyacrylamide gel electrophoresis and is stable in long term storage. The enzyme has a molecular weight of approximately 95,000. The single methylating capacity of this adenine-1 methyltransferase, using Escherichia coli tRNA2Glu, is methylation of the invariant adenine in the GTpsiC loop. The methylation reaction is dependent on added cation with 20 to 40 mM putrescine being most effective. The Km for S-adenosylmethionine was found to be 0.3 micron, while the Ki for the product inhibitor S-adenosylhomocysteine was 0.85 micron. The Km for tRNAMetf is 12 nM while that for tRNAGlu2 is 33 nM.
一种依赖S-腺苷甲硫氨酸的tRNA（腺嘌呤-1）-甲基转移酶已从大鼠肝脏中纯化出来，纯化倍数达8000倍。该制剂在聚丙烯酰胺凝胶电泳上呈现单一条带，并且在长期储存中稳定。该酶的分子量约为95,000。这种腺嘌呤-1甲基转移酶利用大肠杆菌tRNA2Glu的单一甲基化能力，是对GTpsiC环中不变腺嘌呤进行甲基化。甲基化反应依赖于添加的阳离子，其中20至40 mM的腐胺最为有效。发现S-腺苷甲硫氨酸的Km为0.3微米，而产物抑制剂S-腺苷高半胱氨酸的Ki为0.85微米。tRNAMetf的Km为12 nM，而tRNAGlu2的Km为33 nM。
