Biomaterial Database

Metabolism of 4-pentenoic acid and inhibition of thiolase by metabolites of 4-pentenoic acid. 1983

H Schulz

The metabolism of 4-pentenoic acid, a hypoglycemic agent and inhibitor of fatty acid oxidation, has been studied in rat heart mitochondria. Confirmed was the conversion of 4-pentenoic acid to 2,4-pentadienoyl coenzyme A (CoA), which either is directly degraded via beta-oxidation or is first reduced in a NADPH-dependent reaction before it is further degraded by beta-oxidation. At pH 6.9, the NADPH-dependent reduction of 2,4-pentadienoyl-CoA proceeds 10 times faster than its degradation by beta-oxidation. At pH 7.8, this ratio is only 2 to 1. The direct beta-oxidation of 2,4-pentadienoyl-CoA leads to the formation of 3-keto-4-pentenoyl-CoA, which is highly reactive and spontaneously converts to another 3-ketoacyl-CoA derivative (compound X). 3-Keto-4-pentenoyl-CoA is a poor substrate of 3-ketoacyl-CoA thiolase (EC 2.3..1.16) whereas compound X is not measurably acted upon by this enzyme. The effects of several metabolites of 4-pentenoic acid on the activity of 3-ketoacyl-CoA thiolase were studied. 3,4-Pentadienoyl-CoA is a weak inhibitor of this enzyme that is protected against the inhibition by acetoacetyl-CoA. The most effective inhibitor of 3-ketoacyl-CoA thiolase was found to be 3-keto-4-pentenoyl-CoA, which inhibits the enzyme in both a reversible and irreversible manner. The reversible inhibition is possibly a consequence of the inhibitor being a poor substrate of 3-ketoacyl-CoA thiolase. It is concluded that 4-pentenoic acid is metabolized in mitochondria by two pathways. The minor yields 3-keto-4-pentenoyl-CoA, which acts both as a reversible and as a irreversible inhibitor of 3-ketoacyl-CoA thiolase and consequently of fatty acid oxidation.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008929	Mitochondria, Heart	The mitochondria of the myocardium.	Heart Mitochondria,Myocardial Mitochondria,Mitochondrion, Heart,Heart Mitochondrion,Mitochondria, Myocardial
D005229	Fatty Acids, Monounsaturated	Fatty acids which are unsaturated in only one position.	Monounsaturated Fatty Acid,Acid, Monounsaturated Fatty,Acids, Monounsaturated Fatty,Fatty Acid, Monounsaturated,Monounsaturated Fatty Acids
D005231	Fatty Acids, Unsaturated	FATTY ACIDS in which the carbon chain contains one or more double or triple carbon-carbon bonds.	Fatty Acids, Polyunsaturated,Polyunsaturated Fatty Acid,Unsaturated Fatty Acid,Polyunsaturated Fatty Acids,Acid, Polyunsaturated Fatty,Acid, Unsaturated Fatty,Acids, Polyunsaturated Fatty,Acids, Unsaturated Fatty,Fatty Acid, Polyunsaturated,Fatty Acid, Unsaturated,Unsaturated Fatty Acids
D000101	Acetyl-CoA C-Acetyltransferase	An enzyme that catalyzes the formation of acetoacetyl-CoA from two molecules of ACETYL COA. Some enzymes called thiolase or thiolase-I have referred to this activity or to the activity of ACETYL-COA C-ACYLTRANSFERASE.	Acetoacetyl CoA Thiolase,Acetyl Coenzyme A Acetyltransferase,Acetyl-CoA Acetyltransferase,Acetyl CoA Acetyltransferase,Acetyl CoA C Acetyltransferase,Acetyltransferase, Acetyl-CoA,C-Acetyltransferase, Acetyl-CoA,CoA Thiolase, Acetoacetyl,Thiolase, Acetoacetyl CoA
D000102	Acetyl-CoA C-Acyltransferase	Enzyme that catalyzes the final step of fatty acid oxidation in which ACETYL COA is released and the CoA ester of a fatty acid two carbons shorter is formed.	3-Ketoacyl CoA Thiolase,3-Ketothiolase,Acetyl CoA Acyltransferase,Acetyl Coenzyme A Acyltransferase,beta-Ketothiolase,2-Methylacetoacetyl CoA Thiolase,3-Oxoacyl CoA Thiolase,3-Oxoacyl-Coenzyme A Thiolase,beta-Ketoacyl Thiolase,Acetyl CoA C Acyltransferase,Acyltransferase, Acetyl CoA,C-Acyltransferase, Acetyl-CoA,CoA Acyltransferase, Acetyl,CoA Thiolase, 2-Methylacetoacetyl,CoA Thiolase, 3-Ketoacyl,CoA Thiolase, 3-Oxoacyl,Thiolase, 2-Methylacetoacetyl CoA,Thiolase, 3-Ketoacyl CoA,Thiolase, 3-Oxoacyl CoA,Thiolase, 3-Oxoacyl-Coenzyme A,Thiolase, beta-Ketoacyl,beta Ketoacyl Thiolase,beta Ketothiolase
D000123	Acetyltransferases	Enzymes catalyzing the transfer of an acetyl group, usually from acetyl coenzyme A, to another compound. EC 2.3.1.	Acetyltransferase
D000217	Acyltransferases	Enzymes from the transferase class that catalyze the transfer of acyl groups from donor to acceptor, forming either esters or amides. (From Enzyme Nomenclature 1992) EC 2.3.	Acyltransferase
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013329	Structure-Activity Relationship	The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.	Relationship, Structure-Activity,Relationships, Structure-Activity,Structure Activity Relationship,Structure-Activity Relationships