Interaction between calmodulin and five different spin-labelled chlorophenothiazines.
The binding to purified calmodulin of five spin-labelled derivatives of chlorophenothiazine was investigated by e.s.r. spectrometry and by the antagonizing potency on the calmodulin-dependent activation of myosin light chain kinase. The results of a comparative study and the influence of pH and ionic strength on the binding support the occurrence of an electrostatic binding involving the terminal amino group of the side-chain of the chlorophenothiazine. These results are discussed in relation to the specificity of the interaction that holds the antipsychotic drug-calmodulin complex together.
D002118:Calcium / Q000494:pharmacology; D002147:Calmodulin / Q000378:metabolism*; D003497:Cyclic N-Oxides / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy; D006863:Hydrogen-Ion Concentration; D009219:Myosin-Light-Chain Kinase; D009994:Osmolar Concentration; D010640:Phenothiazines / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects; D011494:Protein Kinases / Q000378:metabolism; D013113:Spin Labels
D002147:Calmodulin; D003497:Cyclic N-Oxides; D010640:Phenothiazines; D013113:Spin Labels; D011494:Protein Kinases; D009219:Myosin-Light-Chain Kinase; D002118:Calcium