Influence of the aromatic moiety in α- and β-arylalanines on their biotransformation with phenylalanine 2,3-aminomutase from Pantoea agglomerans
作者:Andrea Varga、Gergely Bánóczi、Botond Nagy、László Csaba Bencze、Monica Ioana Toşa、Ákos Gellért、Florin Dan Irimie、János Rétey、László Poppe、Csaba Paizs
DOI:10.1039/c6ra02964g
日期:——
isomerization of various racemic α- and β-arylalanines catalysed by phenylalanine 2,3-aminomutase from Pantoea agglomerans (PaPAM) was investigated. Both α- and β-arylalanines were accepted as substrates when the aryl moiety was relatively small, like phenyl, 2-, 3-, 4-fluorophenyl or thiophen-2-yl. While 2-substituted α-phenylalanines bearing bulky electron withdrawing substituents did not react, the corresponding
在这项研究中,Pantoea agloglomerans的苯丙氨酸2,3-氨基变位酶催化的各种外消旋α-和β-芳基丙氨酸的对映异构体选择性异构化(PaPAM)进行了调查。当芳基部分相对较小时,如苯基,2-,3-,4-氟苯基或噻吩-2-基,α-和β-芳基丙氨酸均被接受为底物。尽管带有大量吸电子取代基的2-取代的α-苯丙氨酸没有反应,但相应的取代的β-芳基类似物却被迅速转化。3-和4-取代的α-芳基丙氨酸的转化顺利进行,而相应的β-芳基丙氨酸的转化不良或不存在。在pH 7-9范围内,对外消旋α-或β-(噻吩-2-基)丙氨酸的转化率没有明显影响,而氨的浓度(碳酸铵从50 mM增加到1000 mM)则抑制了异构化逐步减少副产物的量(即(E检测到)-3-(噻吩-2-基)丙烯酸。在所有情况下,产物的高ee值表明优异的对映异构体选择性和异构化的立体特异性,除了来自β-异构体的(S)-2-硝基-α-苯丙氨酸(ee