bi8b00145_si_001.pdf (3.49 MB)
0/0

Multiple Reaction Products from the Hydrolysis of Chiral and Prochiral Organophosphate Substrates by the Phosphotriesterase from Sphingobium sp. TCM1

Download (3.49 MB)
journal contribution
posted on 07.03.2018 by Andrew N. Bigley, Tamari Narindoshvili, Dao Feng Xiang, Frank M. Raushel
The phosphotriesterase from Sphingobium sp. TCM1 (Sb-PTE) is notable for its ability to hydrolyze organophosphates that are not substrates for other enzymes. In an attempt to determine the catalytic properties of Sb-PTE for hydrolysis of chiral phosphotriesters, we discovered that multiple phosphodiester products are formed from a single substrate. For example, Sb-PTE catalyzes the hydrolysis of the RP-enantiomer of methyl cyclohexyl p-nitrophenyl phosphate with exclusive formation of methyl cyclohexyl phosphate. However, the enzyme catalyzes hydrolysis of the SP-enantiomer of this substrate to an equal mixture of methyl cyclohexyl phosphate and cyclohexyl p-nitrophenyl phosphate products. The ability of this enzyme to catalyze the hydrolysis of a methyl ester at the same rate as the hydrolysis of a p-nitrophenyl ester contained within the same substrate is remarkable. The overall scope of the stereoselective properties of this enzyme is addressed with a library of chiral and prochiral substrates.

History

Exports