Purification and properties of pig heart crotonase and the presence of short chain and long chain enoyl coenzyme A hydratases in pig and guinea pig tissues

• Published in: The Journal of biological chemistry Vol. 252; no. 2; pp. 542 - 547
• Main Authors: Fong, J.C, Schulz, H
• Format: Journal Article
• Language: English
• Published: United States American Society for Biochemistry and Molecular Biology 01-01-1977
• Subjects: animal science; Animals; Cattle; Coenzyme A; Crotonates; Drug Stability; Guinea Pigs; Hydro-Lyases - isolation & purification; Hydro-Lyases - metabolism; Liver - enzymology; livestock; Mitochondria, Liver - enzymology; Molecular Weight; Myocardium - enzymology; Organ Specificity; Species Specificity; Structure-Activity Relationship; Swine; zoology
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/s0021-9258(17)32751-5

A short chain enoyl-CoA hydratase (crotonase) from pig heart has been purified to apparent homogeneity. The enzyme has an
estimated native molecular weight of 155,000 and appears to be composed of six subunits of molecular weight 27,300. A study
of the kinetic properties of the enzyme revealed that the maximal velocity decreases nearly linearly with increasing chain
length of the substrates from 1,670 units/mg with crotonyl-CoA to 40 units/mg with hexadecenoyl-CoA. However, the same Km
values of 30 muM were obtained for all substrates except for crotonyl-CoA for which a value of 13 muM was determined. Since
the presence of both crotonase and long chain enoyl-CoA hydratase in pig heart has been reported earlier, the presence of
the same two enoyl-CoA hydratases in various tissues of several animals was investigated by sequential extraction and chromatography
on hydroxylapatite of tissue homogenates. The simultaneous occurrence of both types of enoyl-CoA hydratase in tissues of pig
and guinea pig has thus been established. It is proposed that the complementary actions of the two enoyl-CoA hydratases assures
a high rate of hydration of enoyl-CoA intermediates of all chain lengths in fatty acid oxidation.