Proton Exchange in Type II Isopentenyl Diphosphate Isomerase

Abstract

[reaction: see text] Type II isopentenyl diphosphate:dimethylallyl diphosphate (IPP:DMAPP) isomerase from Synechocystis PCC 6803 catalyzes the interconversion of IPP and DMAPP. Upon incubation of the enzyme with IPP or DMAPP in 2H2O, one deuterium is incorporated into the C2 methylene of IPP, two deuteriums are incorporated at C4, and three deuteriums are incorporated into the (E)-methyl of DMAPP.