title: L-Arginine reduces thioflavin T fluorescence but not fibrillation of bovine serum albumin.
abstract: This work examines the effects of L-arginine (L-Arg) on the aggregation and amyloid fibrillation of bovine serum albumin (BSA). We demonstrate that L-Arg dose-dependently reduces thioflavin T (ThT) fluorescence of BSA within the L-Arg concentration range used (0-1.4 M). However, as revealed by electron microscopy, size exclusion chromatography, and dynamic light scattering results, L-Arg does not prevent amyloid-like fibril formation by BSA. We conclude that L-Arg competes against ThT for binding sites on BSA amyloid-like fibrils, leading to biased results in ThT fluorescence measurements. Moreover, the use of ThT fluorescence assay to screen for potential inhibitors against amyloid fibrillation can give misleading results.
authors.affiliation: Department of Chemical Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd., Taipei, 10617, Taiwan.
authors.forename: Kuan-Nan
authors.initials: KN
authors.lastname: Liu
authors.forename: Hsiang-Yun
authors.initials: HY
authors.lastname: Wang
authors.forename: Chih-Yuan
authors.initials: CY
authors.lastname: Chen
authors.forename: Steven S-S
authors.initials: SS
authors.lastname: Wang
mesh_terms: D000818:Animals; D001120:Arginine / Q000737:chemistry*; D052160:Benzothiazoles; D001665:Binding Sites; D002417:Cattle; D005453:Fluorescence; D046529:Microscopy, Electron, Transmission; D011485:Protein Binding; D011487:Protein Conformation; D012710:Serum Albumin, Bovine / Q000737:chemistry* / Q000648:ultrastructure; D013844:Thiazoles / Q000737:chemistry*
chemical_list: D052160:Benzothiazoles; D013844:Thiazoles; C009462:thioflavin T; D012710:Serum Albumin, Bovine; D001120:Arginine