Characterization of radicals in anaerobic degradation of benzoate, acytelene, and glycol ethers

• Applicant: Professor Dr. Bernhard Schink
• Subject Area: Metabolism, Biochemistry and Genetics of Microorganisms
• Term: from 1999 to 2007
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5177536

In fermenting and sulfate-reducing bacteria, the reductive transformation of benzoyl-CoA is catalyzed by an enzyme system different from that observed in nitrate-reducing bacteria. The reaction leads to cyclohexene carboxyl-CoA, and appears to be ATP-independent. Formation of a radical carbonyl derivative is proposed for the first step which is subsequently reduced to cyclohexene carboxyl-CoA. A second project deals with the fermentative degradation of ethylene glycol ethers which is supposed to proceed via a radical mechanism analogous to the reaction catalyzed by diol dehydratases. In a third project, the molybdopterin-containing enzyme acetylene hydratase will be investigated with respect to the formation of a pterin-centered radical and its role in catalysis. Clearly, in all cases protein and substrate centered radicals will be identified by EPR/ENDOR spectroscopy employing both rapid quench and spin trap techniques.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1071: Radikale in der enzymatischen Katalyse
• Participating Person: Professor Dr. Peter M. H. Kroneck