Kinetic Mechanism of Protein N-terminal Methyltransferase 1
Kinetic Mechanism of Protein N-terminal Methyltransferase 1
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DOI：
10.1074/jbc.m114.626846
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发表时间：
2015-05-01
影响因子：
4.8
通讯作者：
Huang, Rong
中科院分区：
文献类型：
--
作者：
Richardson, Stacie L.;Mao, Yunfei;Huang, Rong
蛋白质n端甲基转移酶1 （NTMT1）催化甲基从s -腺苷基- l-蛋氨酸转移到蛋白质α -胺，形成s -腺苷基- l-同型半胱氨酸和α - n -甲基化蛋白。NTMT1是一个有趣的潜在抗癌靶点，因为它在胃肠道癌症中过表达，并在细胞有丝分裂中起重要作用。为了深入了解NTMT1的生化机制，我们利用荧光分析和质谱分析表征了重组NTMT1的动力学机制。初始速度、产物和终端抑制的结果表明，NTMT1的甲基化是通过随机顺序的Bi - Bi机制进行的。此外，我们的加工性研究表明，NTMT1通过多甲基化的分配机制进行。总之，我们的研究为NTMT1的动力学机制提供了新的认识，为开发基于机制的抑制剂奠定了基础。
The protein N-terminal methyltransferase 1 (NTMT1) catalyzes the transfer of the methyl group from the S-adenosyl-L-methionine to the protein alpha-amine, resulting in formation of S-adenosyl-L-homocysteine and alpha-N-methylated proteins. NTMT1 is an interesting potential anticancer target because it is overexpressed in gastrointestinal cancers and plays an important role in cell mitosis. To gain insight into the biochemical mechanism of NTMT1, we have characterized the kinetic mechanism of recombinant NTMT1 using a fluorescence assay and mass spectrometry. The results of initial velocity, product, and dead-end inhibition studies indicate that methylation by NTMT1 proceeds via a random sequential Bi Bi mechanism. In addition, our processivity studies demonstrate that NTMT1 proceeds via a distributive mechanism for multiple methylations. Together, our studies provide new knowledge about the kinetic mechanism of NTMT1 and lay the foundation for the development of mechanism-based inhibitors.