[The use of parameters of non-uniform widening of probe fluorescence spectra in the study of conformation changes in Ca2+-binding proteins].
The parameters of inhomogeneous broadening in the fluorescence spectra of 1-anilinonaphthalene-8-sulfonate and N-phenyl-1-naphthylamine, recorded in the systems with respective proteins, have been analyzed in order to shed light on the mechanism of interaction between Ca2+ ions and calmodulin, troponin C and parvalbumin. It was shown that only calmodulin and troponin C but not parvalbumin bind calcium ions with concomitant formation of hydrophobic sites that are responsible for interaction with the "executor enzymes". The relative pools of the probes adsorbed in the hydrophobic sites and polarity of the latter were assessed. These parameters in calmodulin obtained from the brain of spontaneously hypertensive rats or normotensive rats do not differ. It was established that trifluoroperazine and verapamil inhibit the calmodulin-dependent enzymes by essentially different mechanisms. Trifluoroperazine diminishes the relative pool of the adsorbed probe and enhances the polarity of the calmodulin binding sites, whereas verapamil affects these parameters in the opposite direction.
D015057:1-Naphthylamine / Q000031:analogs & derivatives; D000817:Anilino Naphthalenesulfonates; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D002417:Cattle; D004910:Erythrocyte Membrane / Q000378:metabolism; D005453:Fluorescence; D005456:Fluorescent Dyes; D066298:In Vitro Techniques; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY
D000817:Anilino Naphthalenesulfonates; D002135:Calcium-Binding Proteins; D005456:Fluorescent Dyes; C005444:N-phenyl-1-naphthylamine; D015057:1-Naphthylamine
Primenenie parametrov neodnorodnogo ushireniia spektrov fluorestsentsii zondov dlia izucheniia konformatsionnykh izmeneniĭ Ca2+-sviazyvaiushchikh belkov.