10.1021/acs.biochem.8b00145.s001 Andrew N. Bigley Andrew N. Bigley Tamari Narindoshvili Tamari Narindoshvili Dao Feng Xiang Dao Feng Xiang Frank M. Raushel Frank M. Raushel Multiple Reaction Products from the Hydrolysis of Chiral and Prochiral Organophosphate Substrates by the Phosphotriesterase from <i>Sphingobium</i> sp. TCM1 American Chemical Society 2018 TCM 1 Sb methyl cyclohexyl p methyl cyclohexyl phosphate enzyme catalyzes hydrolysis enantiomer ester Prochiral Organophosphate Substrates ability nitrophenyl phosphate products substrate Multiple Reaction Products Sphingobium sp PTE 2018-03-07 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Multiple_Reaction_Products_from_the_Hydrolysis_of_Chiral_and_Prochiral_Organophosphate_Substrates_by_the_Phosphotriesterase_from_i_Sphingobium_i_sp_TCM1/5975305 The phosphotriesterase from <i>Sphingobium</i> sp. TCM1 (<i>Sb</i>-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 <i>Sb</i>-PTE for hydrolysis of chiral phosphotriesters, we discovered that multiple phosphodiester products are formed from a single substrate. For example, <i>Sb</i>-PTE catalyzes the hydrolysis of the <i>R</i><sub>P</sub>-enantiomer of methyl cyclohexyl <i>p</i>-nitrophenyl phosphate with exclusive formation of methyl cyclohexyl phosphate. However, the enzyme catalyzes hydrolysis of the <i>S</i><sub>P</sub>-enantiomer of this substrate to an equal mixture of methyl cyclohexyl phosphate and cyclohexyl <i>p</i>-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 <i>p</i>-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.