title: A spectroscopic study of 2-[4'-(dimethylamino)phenyl]-benzothiazole binding to insulin amyloid fibrils.
abstract: The spectroscopic properties of 2-[4'-(dimethylamino)phenyl]-benzothiazole (BTA-2) in solution and in the presence of amyloid fibrils were investigated using absorption and fluorescence spectroscopy. Solution studies show that BTA-2 forms micelles in aqueous solutions, but that the dye can be solvated upon the addition of acetonitrile (CH(3)CN). BTA-2 binds to amyloid fibrils in solution leading to a characteristic blue-shift in the emission spectrum and an increase in fluorescence intensity. However, in solutions with increasing CH(3)CN concentration, there was a marked decrease in binding of the BTA-2 to fibrils. Studies demonstrating the effect of BTA-2 concentration on binding were performed. A comparison with the standard amyloid fluorescent marker, thioflavin T (ThT), showed that BTA-2 is more fluorescent, making it an excellent dye to label amyloid samples.
authors.affiliation: Department of Chemistry and Biochemistry, Center for Nano and Molecular Science and Technology, and Texas Materials Institute, University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Catherine C
authors.initials: CC
authors.lastname: Kitts
authors.forename: David Anton
authors.initials: DA
authors.lastname: Vanden Bout
mesh_terms: D000042:Absorption; D000682:Amyloid / Q000378:metabolism*; D000814:Aniline Compounds / Q000737:chemistry* / Q000378:metabolism*; D000818:Animals; D052160:Benzothiazoles / Q000737:chemistry* / Q000378:metabolism*; D002417:Cattle; D005454:Fluorescence Polarization; D006863:Hydrogen-Ion Concentration; D007328:Insulin / Q000378:metabolism*; D011485:Protein Binding; D012996:Solutions; D012997:Solvents / Q000737:chemistry; D013057:Spectrum Analysis
chemical_list: C554933:2-(4'-(dimethylamino)phenyl)benzothiazole; D000682:Amyloid; D000814:Aniline Compounds; D052160:Benzothiazoles; D007328:Insulin; D012996:Solutions; D012997:Solvents; C005465:benzothiazole