Substrate and metal specificity in the enzymic synthesis of cyclic monoterpenes from geranyl and neryl pyrophosphate

Add time:07/21/2019    Source:sciencedirect.com

A partially purified enzyme (carbocyclase) from the flavedo of Citrus limonum formed α-pinene, β-pinene, limonene, and γ-terpinene from geranyl pyrophosphate (GPP) and neryl pyrophosphate. The maximum specific activities obtained were 7.0 and 3.6 nmol/ min/mg, respectively. Cross-inhibition by the two substrates were observed and the ability to utilize neryl pyrophosphate was almost completely lost with aging. Citronellyl pyrophosphate and dimethylallyl pyrophosphate were the most effective inhibitors of carbocyclase. Isopentenyl pyrophosphate, the monophosphate esters of nerol and geraniol, as well as inorganic pyrophosphate were much less effective inhibitors. The enzyme had an absolute requirement for Mn2+. It could be replaced with about 2% effectiveness by Mg2+ and Co2+. Kinetic studies showed that the observed reaction rate correlates with the calculated concentration of the GPP (Mn2+)2 species. Previous evidence with nonenzymatic reactions and the results presented support the view that the mechanism of carbocyclase may be the intramolecular analog of prenyltransferase.

We also recommend Trading Suppliers and Manufacturers of GERANYL MONOPHOSPHATE (cas 16750-99-5). Pls Click Website Link as below: cas 16750-99-5 suppliers

Prev:Stereochemical disposition of the geminal dimethyl groups in the enzymatic cyclization of geranyl diphosphate to (+)-bornyl diphosphate by recombinant (+)-bornyl diphosphate synthase from Salvia officinalis
Next:Biosynthesis of monoterpene hydrocarbons from [1-3H]neryl pyrophosphate and [1-3H]geranyl pyrophosphate by soluble enzymes from Citrus limonum)