Carboxylation of epoxides to beta-keto acids in cell extracts of Xanthobacter strain Py2.
AUTOR(ES)
Allen, J R
RESUMO
A novel enzymatic reaction involved in the metabolism of aliphatic epoxides by Xanthobacter strain Py2 is described. Cell extracts catalyzed the CO2-dependent carboxylation of propylene oxide (epoxypropane) to form acetoacetate and beta-hydroxybutyrate. The time courses of acetoacetate and beta-hydroxybutyrate formaton indicate that acetoacetate is the primary product of propylene oxide carboxylation and that beta-hydroxybutyrate is a secondary product formed by the reduction of acetoacetate. Analogous C5 carboxylation products were identified with 1,2-epoxybutane as the substrate. In the absence of CO2, propylene oxide and 1,2-epoxybutane were isomerized to form acetone and methyl ethyl ketone, respectively, as dead-end products. The carboxylation of short-chain epoxides to beta-keto acids is proposed to serve as the physiological reaction for the metabolism of aliphatic epoxides in Xanthobacter strain Py2.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=177824Documentos Relacionados
- Aliphatic and chlorinated alkenes and epoxides as inducers of alkene monooxygenase and epoxidase activities in Xanthobacter strain Py2.
- Carbon dioxide fixation in the metabolism of propylene and propylene oxide by Xanthobacter strain Py2.
- Rearrangement of beta,gamma-unsaturated esters with thallium trinitrate: synthesis of indans bearing a beta-keto ester moiety
- Involvement of an ATP-dependent carboxylase in a CO2-dependent pathway of acetone metabolism by Xanthobacter strain Py2.
- Characterization of three protein components required for functional reconstitution of the epoxide carboxylase multienzyme complex from Xanthobacter strain Py2.
