title: The increase in human antithrombin III tryptophan fluorescence produced by heparin.
abstract: The increase in fluorescence of human antithrombin III has been used to study the binding of a semi-synthetic heparin analogue. One molecule of heparin were found to bind with an association constant of 8.9 . 10(4) M-1. The intrinsic fluorescence of antithrombin III exhibits a fluorescence quantum yield of 0.17. Upon addition of heparin a marked increase in the protein fluorescence quantum yield is observed.
mesh_terms: D000991:Antithrombins / Q000378:metabolism; D001665:Binding Sites; D006493:Heparin / Q000031:analogs & derivatives / Q000378:metabolism*; D006801:Humans; D008024:Ligands; D011485:Protein Binding; D013050:Spectrometry, Fluorescence; D014364:Tryptophan
chemical_list: D000991:Antithrombins; D008024:Ligands; D014364:Tryptophan; D006493:Heparin