title: H-NMR studies of calmodulin: the effect of W-7 (N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide) and Ca2+ on conformational changes of calmodulin.
abstract: The effect of W-7 (N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide), a calmodulin antagonist, on the structure of calmodulin was studied with 400 MHz H-NMR. W-7 affected the calcium-induced conformational change of calmodulin in several resonances. One resonant peak was assigned to the His-107 H2 proton. The other peaks were seen in the area of the methionine methyl group (around 2 ppm) and the high-field methyl group (0-1 ppm), these peaks cannot be assigned. The modifying effect of W-7 on the methyl-group resonances of calmodulin fully bound with Ca2+ was similar to that of trifluoperazine. However, the effect on the His-107 H2 proton was unique to W-7.
mesh_terms: D002118:Calcium / Q000494:pharmacology*; D002147:Calmodulin / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D011487:Protein Conformation / Q000187:drug effects; D013449:Sulfonamides / Q000494:pharmacology*; D014268:Trifluoperazine / Q000494:pharmacology
chemical_list: D002147:Calmodulin; D013449:Sulfonamides; D014268:Trifluoperazine; C017967:W 7; D002118:Calcium