作者:William H. Johnson、Tyler M. M. Stack、Stephanie M. Taylor、Elizabeth A. Burks、Christian P. Whitman
DOI:10.1021/acs.biochem.6b00552
日期:2016.7.26
Cl) or the source of the enzyme (Pp or Lc) does not change the stereochemical outcome. One mechanism that can account for the results is the ketonization of the 5-substituted dienol to the α,β-unsaturated ketone (placing a deuteron at C-5 in D2O), followed by the conjugate addition of water (placing a deuteron at C-3). The stereochemical outcome for VPH (from Pp and Lc) is the same as that reported
甲立体化学分析已经在两个vinylpyruvate水合酶(VPH),其将2-羟基-2,4-戊二烯酸为2-酮-4-进行小号-hydroxypentanoate在元-fission通路。具有这种途径的细菌菌株可以使用芳香族化合物作为唯一的能源和碳源。使用2-羟基-2,4-戊二烯酸酯的5-甲基和5-氯衍生物以及恶臭假单胞菌mt-2(Pp)和霍乱单胞菌SP-6(Lc)的酶进行分析。在这两种生物中,VPH与该途径中的先前酶(4-草酰巴豆酸脱羧酶(4-OD))形成复合物。在D 2O,氘核被Pp和Lc酶立体定向地掺入产物的C-3和C-5位置。因此,络合物产生(3 S,5 S)-3,5- [di-D] -2-酮-4 S-羟基己酸酯和(3 S,5 R)-3,5- [di-D]- 2-酮基4 R-羟基-5-氯戊酸酯(由于优先顺序的更改,分别为4 R和5 R)。在C-5处的取代(CH 3或Cl)或酶的来源(Pp