Optimization of a biomimetic transamination reaction
Optimization of a biomimetic transamination reaction
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DOI：
10.1021/ja802495w
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发表时间：
2008-09-03
影响因子：
15
通讯作者：
Francis, Matthew B.
中科院分区：
文献类型：
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作者：
Scheck, Rebecca A.;Dedeo, Michel T.;Francis, Matthew B.
对于一系列蛋白质底物，N-末端转氨基为在单一位置安装反应酮或醛官能团提供了一种方便的方法。在这里，我们报告了N-末端残基的同一性对与5‘-磷酸吡哆醛(PLP)反应生成的产物分布的影响。本研究通过固相多肽合成和详细的液-质联用分析相结合的方法完成。许多N端氨基酸提供了所需转氨基产物的高产率，但一些残基(组氨酸、色氨酸、赖氨酸和Pro)与PLP本身产生加合物。观察到N-末端的半胱氨酸和丝氨酸残基除了转氨化作用外还经历了β-消除，并且N-末端谷氨酰胺的转氨化产物对随后的肟形成尝试具有抵抗力。通过筛选多肽底物产生的信息被成功地应用于蛋白质靶标，将最初无反应的末端改变为可以高(70%)产率修饰的末端。因此，这些研究增加了我们对反应的预测能力，无论是在提高转化率方面，还是在抑制反应副产物方面。提供了一套可用于增加该反应对特定感兴趣蛋白质的适用性的初始指南。
For a range of protein substrates, N-terminal transamination offers a convenient way to install a reactive ketone or aldehyde functional group at a single location. We report herein the effects of the identity of N-terminal residues on the product distribution generated upon reaction with pyridoxal 5'-phosphate (PLP). This study was accomplished through the combination of solid-phase peptide synthesis with detailed liquid chromatography-mass spectrometry analysis. Many N-terminal amino acids provided high yields of the desired transaminated products, but some residues (His, Trp, Lys, and Pro) generated adducts with PLP itself. N-terminal Cys and Ser residues were observed to undergo beta-elimination in addition to transamination, and the transamination product of N-terminal Gln was resistant to subsequent oxime formation attempts. The information generated through the screening of peptide substrates was successfully applied to a protein target, changing an initially unreactive terminus into one that could be modified in high (70%) yield. Thus, these studies have increased our predictive power for the reaction, both in terms of improving conversion and suppressing reaction byproducts. An initial set of guidelines that may be used to increase the applicability of this reaction to specific proteins of interest is provided.