title: Structural properties of sarcoplasmic reticulum Ca2+-ATPase as studied by intrinsic protein fluorescence.
abstract: 1. From the intrinsic fluorescence spectral properties and fluorescence quenching experiments done with acrylamide and iodide, using native sarcoplasmic reticulum vesicles, purified ATPase and ATPase solubilized with 1% Triton X-100, it is deduced that practically all the fluorescent tryptophanyl residues of this protein belong to a single population showing similar hydrophobic microenvironments. 2. Both acrylamide and iodide seem to be able to penetrate through the sarcoplasmic reticulum membrane. 3. The intrinsic fluorescence of the Ca2+-ATPase due to tryptophan residues probably buried inside the membrane is used as a tool to follow thermotropic changes in membrane fluidity of reconstituted systems.
mesh_terms: D000818:Animals; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D007700:Kinetics; D009132:Muscles / Q000201:enzymology; D011817:Rabbits; D012519:Sarcoplasmic Reticulum / Q000201:enzymology*; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics
chemical_list: D000252:Calcium-Transporting ATPases