Stereochemistry of reactions of the inhibitor/substrates l- and d-β-chloroalanine with β-mercaptoethanol catalysed by l-aspartate aminotransferase and d-amino acid aminotransferase respectively
作者:Benjamin Adams、Kreingkrai Lowpetch、Faye Thorndycroft、Sheena M. Whyte、Douglas W. Young
DOI:10.1039/b508199h
日期:——
Two members of the α-family of PLP-dependent enzymes, L-aspartate aminotransferase and D-amino acid aminotransferase, have been shown to catalyse β-substitution of L- and D-β-chloroalanine respectively with β-mercaptoethanol, reactions typical of the β-family of PLP-dependent enzymes. The reaction catalysed by L-aspartate aminotransferase has been shown to occur with retention of stereochemistry, a typical outcome for reactions catalysed by β-family enzymes. There are also indications that the reaction catalysed by D-amino acid aminotransferase may involve retention of stereochemistry. Both enzymes have been shown to catalyse exchange at C-3 when the appropriate enantiomer of β-chloroalanine is the substrate.
A short, versatile chemical synthesis of l- and d-amino acids stereoselectively labelled solely in the beta position
作者:Kreingkrai Lowpetch、Douglas W. Young
DOI:10.1039/b508196c
日期:——
L- and D-Amino acids which are stereoselectivelylabelled solely either in the 3-pro-R or in the 3-pro-S-positions have been prepared by a relatively short chemicalsynthesis in ee of 81 to 86%. This involves Sharpless' aminohydroxylation and cyclisation with inversion of stereochemistry at C-2 to give the stereoselectivelylabelled D- and L-aziridines and 10a and 10b, and 8a and 8b. These have previously