Enzymatic kinetic resolution of desmethylphosphinothricin indicates that phosphinic group is a bioisostere of carboxyl group.

ABSTRACT: Escherichia coli glutamate decarboxylase (EcGadB), a pyridoxal 5'-phosphate (PLP)-dependent enzyme, is highly specific for L-glutamate and was demonstrated to be effectively immobilised for the production of γ-aminobutyric acid (GABA), its decarboxylation product. Herein we show that EcGadB quantitatively decarboxylates the L-isomer of D,L-2-amino-4-(hydroxyphosphinyl)butyric acid (D,L-Glu-γ-P_H), a phosphinic analogue of glutamate containing C-P-H bonds. This yields 3-aminopropylphosphinic acid (GABA-P_H), a known GABA_B receptor agonist and provides previously unknown D-Glu-γ-P_H, allowing us to demonstrate that L-Glu-γ-P_H, but not D-Glu-γ-P_H, is responsible for D,L-Glu-γ-P_H antibacterial activity. Furthermore, using GABase, a preparation of GABA-transaminase and succinic semialdehyde dehydrogenase, we show that GABA-P_H is converted to 3-(hydroxyphosphinyl)propionic acid (Succinate-P_H). Hence, PLP-dependent and NADP⁺-dependent enzymes are herein shown to recognise and metabolise phosphinic compounds, leaving unaffected the P-H bond. We therefore suggest that the phosphinic group is a bioisostere of the carboxyl group and the metabolic transformations of phosphinic compounds may offer a ground for prodrug design.

SUBMITTER: De Biase D 

PROVIDER: S-EPMC9814759 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature