Stereochemical Analysis of Isopentenyl Diphosphate Isomerase Type II fromStaphylococcusaureusUsing Chemically Synthesized (S)- and (R)-[2-²H]Isopentenyl Diphosphates

To study the catalysis of isopentenyl diphosphate (IPP) isomerase type 11 from Staphylococcus aureus, which is a flavoprotein catalyzing the interconversion of IPP and dimethylallyl diphosphate, we have chemically synthesized (S)- and (R)-[2-H-2]IPP and carried out stereochemical analysis of the reaction. Our results show that the C-2 deprotonation of IPP by this enzyme is pro-R stereospecific, suggesting a similar stereochemical course as the type I enzyme.