Effects of phosphorylation on the kinetic properties of rat liver ATP-citrate lyase

Houston, B. and Nimmo, H. G. (1985) Effects of phosphorylation on the kinetic properties of rat liver ATP-citrate lyase. Biochimica et Biophysica Acta: Molecular Cell Research, 844(2), pp. 233-239. (doi:10.1016/0167-4889(85)90095-3) (PMID:3871637)

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Abstract

Homogeneous rat liver ATP-citrate lyase (EC 4.1.3.8) was phosphorylated by the catalytic subunit of cAMP-dependent protein kinase. In agreement with other workers, the maximum level of phosphorylation that we observed was approx. 2 mol/mol of tetramer. Phosphorylated and non-phosphorylated forms of ATP-citrate lyase were prepared. Their kinetic properties were examined using an assay system in which the concentrations of Mg · ATP, magnesium·citrate and CoA were varied systematically at a constant concentration of Mg2+. The phosphorylated form had a two-fold higher Km for Mg · ATP than did the non-phosphorylated form, but no other kinetic differences between the two forms were detected. When ATP-citrate lyase was assayed at a concentration of Mg · ATP well below Km, it was found that phosphorylation of the enzyme correlated well with a decrease of approx. 50% in its activity This is the first demonstration that phosphorylation can affect the activity of ATP-citrate lyase.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Nimmo, Professor Hugh
Authors: Houston, B., and Nimmo, H. G.
College/School:College of Medical Veterinary and Life Sciences > Institute of Molecular Cell and Systems Biology
Journal Name:Biochimica et Biophysica Acta: Molecular Cell Research
Publisher:Elsevier
ISSN:0167-4889
ISSN (Online):1879-2596

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