title: Dye binding probes of lipid-binding structures. An investigation of 2-p-toluidinylnaphthylene-6-sulfonate binding to human and bovine prothrombin and fragment 1 in the presence and absence of calcium and magnesium ions.
abstract: TNS (2-p-toluidinylnaphthylene-6-sulfonate) binds to human and bovine prothrombin and Fragment 1 in the absence and presence of added Ca2+. The stoichiometry of TNS binding is 1:1 for human and bovine prothrombin and Fragment 1. The Ca2+-dependence of the fluorescence of TNS bound to bovine prothrombin Fragment 1 yields a modified Hill plot slope of 2.7, which is consistent with the slope obtained by monitoring the Ca2+ dependence of protein fluorescence quenching, CD changes and phospholipid binding. Mg2+ has have no effect on the fluorescence of TNS-prothrombin fluorescence. TNS binding to the amino-terminal region of prothrombin is the first relatively simple probe of the subtle and complex relationship which exists between protein structure and phospholipid binding.
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002417:Cattle; D005456:Fluorescent Dyes / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology*; D009282:Naphthalenesulfonates / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism*; D011485:Protein Binding; D011498:Protein Precursors; D011516:Prothrombin / Q000378:metabolism*; D013045:Species Specificity; D013050:Spectrometry, Fluorescence
chemical_list: D005456:Fluorescent Dyes; D009282:Naphthalenesulfonates; D010446:Peptide Fragments; D011498:Protein Precursors; C029733:prothrombin fragment 1; C009497:2-(4-toluidino)-6-naphthalenesulfonic acid; D011516:Prothrombin; D008274:Magnesium; D002118:Calcium