Source Year: 1997

Isopentenyl diphosphate isomerase (EC 5.3.3.2), which catalyses the reversible isomerization of isopentenyl diphosphate to dimethylallyl diphosphate, is presumed to be involved in rubber biosynthesis, but no direct evidence has been given for its occurrence in rubber latex. This enzyme activity was found in the C-serum powder prepared by lyophilization of centrifuged rubber latex. Characterization of the partially purified enzyme showed aKm > 71 mM for isopentenyl diphosphate, a pH optimum of 7 and an optimum temperature at 37 degree C. Divalent cations (Mg+ or Mn+) and dithiothreitol were required for maximum enzymic activity. Sulfhydryl reagents such as iodoacetamide, p-chloromercuribenzonate and N-ethymaleimide were effective inhibitors.