Expanding the substrate scope of phenylalanine ammonia-lyase from <i>Petroselinum crispum</i> towards styrylalanines
作者:László Csaba Bencze、Alina Filip、Gergely Bánóczi、Monica Ioana Toşa、Florin Dan Irimie、Ákos Gellért、László Poppe、Csaba Paizs
DOI:10.1039/c7ob00562h
日期:——
on the expansion of the substrate scope of phenylalanine ammonia-lyase from Petroselinum crispum (PcPAL) towards the L-enantiomers of racemic styrylalanines rac-1a–d – which are less studied and synthetically challenging unnatural amino acids – by reshaping the aromatic binding pocket of the active site of PcPAL by point mutations. Ammonia elimination from L-styrylalanine (L-1a) catalyzed by non-mutated
本研究着重于从苯丙氨酸氨裂合酶的底物范围的扩大欧芹(PcPAL)朝向所述大号消旋styrylalanines -对映体的外消旋- 1A-d -这是不太研究和合成具有挑战性的非天然氨基酸-通过重塑芳香通过点突变结合PcPAL活性位点的口袋。非突变的PcPAL(wt-PcPAL)催化从L-苯乙烯基丙氨酸(L - 1a)消除氨的k cat / K M值比天然底物L的脱氨基低777倍-Phe。wt-PcPAL催化的反应的计算机模型表明,L-苯乙烯基丙氨酸L - 1a的芳族部分与芳族键合区域中残基F137的苯环之间无用且有两个主要的催化活性构象,并且有害的相互作用活动站点。用较小的疏水残基取代残基F137产生了一个小的突变库(F137X-PcPAL,X为V,A和G),F137V-PcPAL可以从中转化L - styrylalanine,其活性与wt-PcPAL具有可比性L -Phe 此外,F137V