5-(dimethylamino)naphthalene-1-sulfonic acid, a fluorescent probe of the medium chain fatty acid binding site of serum albumin.
Reversible binding of 5-(dimethylamino)-naphthalene-1-sulfonic acid (DNS) to human and bovine serum albumin has been monitored by changes in fluorescence intensity, wavelength maxima, and polarization. DNS has only one major binding site (ka = 5 x 10(6)) and one minor site (ka = 3 x 10(5)) on these proteins. The probe is competitively displaced from its high-affinity site by medium chain fatty acids and by N-acetyl-L-tryptophan. The binding site for DNS is highly hydrophobic and is considerably less polar than the hydrocarbon region of lipid bilayers. Resonance energy transfer indicates that the binding site is located 20.7 +/- 2 A from the single tryptophan residue of human serum albumin.
D001665:Binding Sites; D001667:Binding, Competitive; D003619:Dansyl Compounds; D005227:Fatty Acids; D005454:Fluorescence Polarization; D005456:Fluorescent Dyes; D011485:Protein Binding; D012709:Serum Albumin; D012710:Serum Albumin, Bovine; D013050:Spectrometry, Fluorescence; D013329:Structure-Activity Relationship
D003619:Dansyl Compounds; D005227:Fatty Acids; D005456:Fluorescent Dyes; D012709:Serum Albumin; D012710:Serum Albumin, Bovine; C033853:dansyl acid