... The recent data [1] suggested, that the calcium gradient might be one of the key factors involved in the regulation of the functional states of the Ca2+-ATPase and the Ca2+-channels of Ca2+-store sarcoplasmic reticulum (SR). ... The fluorescent probes pyrene and merocyanine 540 were introduced into the vesicles after loading with various concentrations of calcium (0 mM, 0.3 mM, 1mM, and 3 mM). The protein intrinsic tryptophan fluorescence was also used as a probe [2]. ... 2007 Biophysics dep., ...