title: [Effect of lipids on the binding of calmodulin with cyclic nucleotide phosphodiesterase].
abstract: The effects of various lipids on calmodulin interaction with Ca-dependent phosphodiesterase were investigated. Palmitic, myristic and stearic acids increased the enzyme activity; the degree of the enzyme activation by calmodulin was decreased thereby. Oleic acid produced a weak activating effect on phosphodiesterase but completely blocked calmodulin action. The effects of the fatty acids under study were reversible, the activation constant was equal to 10(-4)-5 X 10(-4) M. In the presence of Ca2+ phosphoinositides and fatty acids changed the fluorescence intensity of dansyl-labelled calmodulin; in the absence of Ca2+ the lipids did not affect protein fluorescence. The lipids had no influence on the protein affinity for Ca2+. During chromatography of phosphodiesterase on calmodulin-Sepharose the enzyme was eluted from the column both in the presence of EGTA and palmitic acid. It was concluded that fatty acids prevent the formation of the calmodulin - phosphodiesterase complex. This effects may both be due to the lipid binding to the enzyme and to calmodulin.
mesh_terms: D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000201:enzymology; D002118:Calcium / Q000494:pharmacology; D002147:Calmodulin / Q000378:metabolism*; D002417:Cattle; D004533:Egtazic Acid / Q000494:pharmacology; D005230:Fatty Acids, Nonesterified / Q000494:pharmacology*; D007700:Kinetics; D011485:Protein Binding; D013329:Structure-Activity Relationship
chemical_list: D002147:Calmodulin; D005230:Fatty Acids, Nonesterified; D004533:Egtazic Acid; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D002118:Calcium
vernacular_title: Vliianie lipidov na sviazyvanie kal'modulina s fosfodiésterazoĭ tsiklicheskikh nukleotidov.