Reactivity and chemical synthesis of L-pyrrolysine -: the 22nd genetically encoded amino acid
Reactivity and chemical synthesis of L-pyrrolysine -: the 22nd genetically encoded amino acid
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DOI：
10.1016/j.chembiol.2004.07.011
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发表时间：
2004-09-01
影响因子：
--
通讯作者：
Chan, MK
中科院分区：
文献类型：
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作者：
Hao, B;Zhao, G;Chan, MK
L-吡咯赖氨酸（L-pyrrolysine）是第22个基因编码的氨基酸，根据M.巴克氏单甲胺甲基转移酶（MtmB）。为了确认L-吡咯赖氨酸的身份，已经在用羟胺、N-甲基羟胺或连二亚硫酸盐处理后测定了MtmB的结构。对这些结构的分析为吡咯啉环的存在提供了额外的支持，并与以前的质谱数据一起，使我们将C-4-取代基分配给甲基。在此基础上，采用化学方法合成了L-吡咯赖氨酸。对这种化学合成的L-吡咯赖氨酸的详细研究使我们能够表征其物理性质，研究其化学稳定性，并阐明其C-4取代基的作用。这种合成L-吡咯赖氨酸的未来应用包括其在体内掺入重组蛋白。
L-pyrrolysine, the 22(nd) genetically encoded amino acid, was previously deduced to be (4R, 5R)-4-substituted-pyrroline-5-carboxylate attached to the epsilon-nitrogen of lysine based on the crystal structure of the M. barkeri monomethylamine methyltransferase (MtmB). To confirm L-pyrrolysine's identity, structures of MtmB have been determined following treatment with hydroxylamine, N-methylhydroxylamine, or dithionite. Analysis of these structures has provided additional support for the presence of the pyrroline ring and, together with previous mass spectroscopy data, has led us to assign the C-4-substituent to a methyl group. Based on this assignment, synthetic L-pyrrolysine was prepared by chemical methods. Detailed study of this chemically synthesized L-pyrrolysine has allowed us to characterize its physical properties, to study its chemical stability, and to elucidate the role Of its C-4 substituent. Future applications of this synthetic L-pyrrolysine include its in vivo incorporation into recombinant proteins.