Distances between the FITC-binding site in the (Ca2++Mg2+)-ATPase from sarcoplasmic reticulum and fluorescent probes located in the membrane.

Fluorescence energy transfer measurements have been performed to investigate the distances between the FITC-binding site in the (Ca2++Mg2+)-ATPase from sarcoplasmic reticulum and 8-aniline-1-naftalenesulfonate (ANS-) and diphenylhexatriene (DPH) localized in different sites of the membrane. The distances calculated between FITC bound to the ATPase and ANS- and DPH in the membrane, were approx. 51 A and 60 A, respectively.