[Fluorescence study of lymphocyte plasma membranes].
ANS binding parameters--dissociation constant, number of binding sites, rotation freedom--are measured by fluorescence studies of a complex between ANS and lymph node cell plasma membranes. Divalent ions, Mg++ and Ca++, enhance the complex fluorescence intensity without shifting its maximum wavelength : this enhancement is induced by affinity and quantum yield increases, while the number of binding sites remains constant. The complex fluorescence quenching by ethacrynic acid shows the presence of free SH groups in the ANS binding site. An energy transfer takes place between membrane protein tryptophan residues and bound ANS ; the energy transfer yield is unaffected by Ca++ ions. A correlation of these results is postulated with the biological activity of the membrane.
D000817:Anilino Naphthalenesulfonates; D000818:Animals; D001665:Binding Sites; D002118:Calcium / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects; D004976:Ethacrynic Acid / Q000494:pharmacology; D007700:Kinetics; D008214:Lymphocytes / Q000187:drug effects; D008274:Magnesium / Q000494:pharmacology; D011485:Protein Binding; D011487:Protein Conformation; D013050:Spectrometry, Fluorescence; D013552:Swine
D000817:Anilino Naphthalenesulfonates; D008274:Magnesium; D004976:Ethacrynic Acid; D002118:Calcium
Etude par fluorescence des membranes plasmiques de lymphocytes