A long chain terpenyl pyrophosphate synthetase from Micrococcus lysodeikticus.

A new terpene pyrophosphate synthetase (Enzyme II) distinct from the previously reported geranylgeranyl pyrophosphate synthetase (Enzyme I) has been isolated from extracts of Micrococcus lysodeikticus and partially purified. Enzyme II catalyzes the elongation of terpenoid ally1 pyrophosphates by isopentenyl pyrophosphate to long chain products. The order of effectiveness of various ally1 pyrophosphates in the elongation reaction is geranyl pyrophosphate > farnesyl pyrophosphate > geranylgeranyl pyrophosphate > dimethylallyl pyrophosphate. Isolation of doubly labeled terpene alcohol from experiments with 14C-isopentenyl pyrophosphate and 3H-farnesyl pyrophosphate and determination of 14C:3H ratios indicates the presence of 7 to 10 isoprene units in the elongation products with a predominance of the C& and C40 alcohols. The same chain length distribution is estimated from the mass spectra of the acidhydrolyzed products of Enzyme II. The incorporation of 32P from 32P-isopentenyl pyrophosphate and the acid lability of the 32P-labeled material indicate that the products formed are pyrophosphate derivatives. In contrast to shorter chain terpene pyrophosphates, the products formed by Enzyme II are not cleaved by bacterial alkaline phosphatase. They also have the unusual property of binding very strongly to protein.