Chicken liver fatty acid synthetase dimer: evidence of asymmetrical structure from iodoacetamide inhibition studies.

Abstract

The condensing component of chicken liver fatty acid synthetase is inhibited by a sulfhydryl reagent, iodoacetamide, with a second-order rate constant of 0.23 M-1 sec-1 at pH 7.0 and 0 degrees. Complete inactivation requires the modification of approximately 8 -SH groups per dimer of the enzyme. Quantitation of the extent of inactivation in the presence of 1 mM acetyl CoA (which completely protects the enzyme against inactivation) and in its absence shows that complete inactivation results from the binding of approximately 1.1 mol of carboxamidomethyl residues per dimer. These data are consistent with the proposed functional asymmetry of the enzyme.

• Authors: S Kumar, E Varagiannis
• Journal: Bioscience reports (Biosci Rep) Vol. 2 Issue 3 Pg. 195-201 (Mar 1982) ISSN: 0144-8463 [Print] England
• PMID: 7066490 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Iodoacetates
• Macromolecular Substances
• Pantetheine
• Acetyl Coenzyme A
• Fatty Acid Synthases
• Cysteine
• Iodoacetamide

Topics

• Acetyl Coenzyme A (pharmacology)
• Animals
• Chickens
• Cysteine
• Fatty Acid Synthases (antagonists & inhibitors)
• Iodoacetamide (pharmacology)
• Iodoacetates (pharmacology)
• Kinetics
• Liver (enzymology)
• Macromolecular Substances
• Pantetheine
• Protein Conformation