Kumar Vikas, Johnson Bryce P, Dimas Dustin A, Singh Shanteri
Institute for Natural Products Applications and Research Technologies, Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019 (USA).
ChemCatChem. 2021 Sep 7;13(17):3781-3788. doi: 10.1002/cctc.202100595. Epub 2021 Jun 23.
The widespread utility of isoprenoids has recently sparked interest in efficient synthesis of isoprene-diphosphate precursors. Current efforts have focused on evaluating two-step "isoprenol pathways," which phosphorylate prenyl alcohols using promiscuous kinases/phosphatases. The convergence on isopentenyl phosphate kinases (IPKs) in these schemes has prompted further speculation about the class's utility in synthesizing non-natural isoprenoids. However, the substrate promiscuity of IPKs in general has been largely unexplored. Towards this goal, we report the biochemical characterization of five novel IPKs from and the assessment of their substrate specificity using 58 alkyl-monophosphates. This study reveals the IPK-catalyzed synthesis of 38 alkyl-diphosphate analogs and discloses broad substrate specificity of IPKs. Further, to demonstrate the biocatalytic utility of IPK-generated alkyl-diphosphates, we also highlight the synthesis of alkyl-l-tryptophan derivatives using coupled IPK-prenyltransferase reactions. These results reveal IPK-catalyzed reactions are compatible with downstream isoprenoid enzymes and further support their development as biocatalytic tools for the synthesis of non-natural isoprenoids.
类异戊二烯的广泛用途最近引发了人们对高效合成异戊二烯二磷酸前体的兴趣。目前的工作重点是评估两步“异戊醇途径”，该途径使用混杂的激酶/磷酸酶将异戊烯醇磷酸化。这些方案中对异戊烯基磷酸激酶（IPK）的趋同促使人们进一步猜测该类酶在合成非天然类异戊二烯中的效用。然而，一般来说，IPK的底物混杂性在很大程度上尚未得到探索。为了实现这一目标，我们报告了来自[具体来源未给出]的五种新型IPK的生化特性，并使用58种烷基单磷酸评估了它们的底物特异性。这项研究揭示了IPK催化合成38种烷基二磷酸类似物，并揭示了IPK广泛的底物特异性。此外，为了证明IPK生成的烷基二磷酸的生物催化效用，我们还强调了使用偶联的IPK-异戊烯基转移酶反应合成烷基-L-色氨酸衍生物。这些结果表明，IPK催化的反应与下游类异戊二烯酶兼容，并进一步支持将其开发为合成非天然类异戊二烯的生物催化工具。
