ABSTRACT
P450 fatty acid decarboxylase OleT from Staphylococcus aureus (OleTsA) is a novel cytochrome P450 enzyme that catalyzes the oxidative decarboxylation of fatty acids to yield primarily terminal alkenes and CO2 or minor α-and β-hydroxylated fatty acids as side-products.In this work,the interactions between a series of cycloalkyl phosphorus heterocycles (CPHs) and OleTsA were investigated in detail by fluores-cence titration experiment,ultraviolet-visible (UV-vis) and 31p NMR spectroscopies.Fluorescence titration experiment results clearly showed that a dynamic quenching occurred when CPH-6,a repre-sentative CPHs,interacted with OleTsA with a binding constant value of 15.2 × 104 M-1 at 293 K.The thermodynamic parameters (△H,△S and △G) showed that the hydrogen bond and van der Waals force played major roles in the interaction between OleTsA and CPHs.The UV-vis and 31p NMR studies indicated the penetration of CPH-6 into the interior environment of OleTsA,which greatly affects the enzymatic activity of OleTsA.Therefore,our study revealed an effective way to use phosphorus hetero-cyclic compounds to modulate the activity of cvtochrome P450 enzymes.