Inactivation of short-chain acyl-coenzyme a dehydrogenase from pig liver by 2-pentynoyl-coenzyme a
Lundberg, N.N.; Thorpe, C.
Archives of Biochemistry and Biophysics 305(2): 454-459
ISSN/ISBN: 0003-9861 PMID: 8373183 DOI: 10.1006/abbi.1993.1446
2-Pentynoyl-CoA is a mechanism-based inactivator of the flavoprotein short-chain acyl-CoA dehydrogenase from pig liver. Inactivation is associated with the formation of an intermediate absorbing at 800 nm and results in the incorporation of 0.86 +/- 0.13 molecules of radiolabeled inhibitor per subunit. A rapid procedure was devised to isolate the labeled peptide. A glutamate residue was identified as the target of 2-pentynoyl-CoA treatment and proved homologous to the proposed catalytic base, GLU376, in the corresponding medium-chain acyl-CoA dehydrogenase sequence. These results are discussed in terms of the lack of conservation of this glutamate residue in the acyl-CoA dehydrogenase enzyme family.