Labelling of L-isoleucine tRNA ligase from Escherichia coli with L-isoleucyl-bromomethyl ketone.
Labelling of L-isoleucine tRNA ligase from Escherichia coli with L-isoleucyl-bromomethyl ketone.
复制标题
用 L-异亮氨酰溴甲基酮标记大肠杆菌的 L-异亮氨酸 tRNA 连接酶。
DOI：
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发表时间：
1976
期刊：
影响因子：
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通讯作者：
M. Kula
中科院分区：
文献类型：
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作者：
P. Rainey;E. Holler;M. Kula
L-Isoleucine: tRNA ligase from Escherichia coli could be irreversibly inactivated by L-isoleucyl-bromomethyl ketone but not by L-isoleucyl-chromethyl ketone. The inactivation rate exhibited a saturation concentration dependence typical for an affinity reagent. L-Isoleucine provided 100% protection against inactivation at saturating concentration, whereas ATP, AMP, and pyrophosphate offered partial protection and tRNAIle, no protection. The ligase was labelled in preparative scale with L-[14C]isoleucyl-bromethyl ketone. The molar ration of label incorporated to enzyme inactivated was close to unity. The protein was subsequently subjected to tryptic digestion and the radioactive peptide isolated and identified. The labelled amino acid proved to be the same cysteine previously reported as being labelled with N-[14C]ethylmaleimide [Kula, M.-R. (1974) FEBS Lett. 46, 130-133].
