How phospholamban could affect the apparent affinity of Ca(2+)-ATPase for Ca(2+) in kinetic experiments.
Binding of phospholamban (PLN) to the Ca(2+)-ATPase of muscle sarcoplasmic reticulum results in a decrease in apparent affinity for Ca(2+) without affecting the true binding constant for Ca(2+) determined in equilibrium binding experiments. It is shown that this can be explained by a scheme in which the ATPase shows two modes of binding for PLN, one of high and one of low affinity; the proposed scheme is not dependent on the kinetic model assumed for the Ca(2+)-ATPase.
Lee
Anthony G
AG
School of Biological Sciences, University of Southampton, SO16 7PX Southampton, UK. agl@soton.ac.uk
D002118:Calcium / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D008956:Models, Chemical; D011485:Protein Binding; D011487:Protein Conformation; D000099211:Phospholamban
D002118:Calcium; D002135:Calcium-Binding Proteins; D000252:Calcium-Transporting ATPases; D000099211:Phospholamban