Isopentenyl diphosphate isomerase and prenyl transferase activities in bottom fraction and C-serum from Hevea latex

Abstract

The isomerization of isopentenyl diphosphate (IDP) to dimethylallyl diphosphate (DMADP), and the formation of oligoprenyl diphosphates as well as polyprenyl diphosphates, catalyzed by IDP-isomerase and polyprenyl transferases, respectively, were observed on incubation of a mixture of14C-IDP and fresh bottom fraction (BF) (separated from centrifuged fresh Hevea latex) which had been preincubated at 4°overnight. The incubation era freeze-dried BF with14C-IDP gave DMADP, farnesyl diphosphate (FDP) and polyprenyl diphosphate as predominant products, while that of fresh BF gave C20- and C40-diphosphates, as well as rubber as main products. FDP was not detected in the incubation of the fresh BF, suggesting that it was consumed as a primer for the formation of rubber and polyprenols. Direct evidence was obtained to show the presence of IDP-isomerase and polyprenyl transferase activities in the BF of fresh latex.