title: Elucidation of μs dynamics of domain-III of human serum albumin during the chemical and thermal unfolding: A fluorescence correlation spectroscopic investigation.
abstract: The local structural dynamics and denaturation profile of domain-III of HSA against guanidine hydrochloride (GnHCl) and temperature has been studied using a coumarin based solvatochromic fluorescent probe p-nitrophenyl coumarin ester (NPCE), covalently tagged to Tyr-411 residue. By the steady state, time-resolved and single molecular level fluorescence studies it has been established that the domain-III of HSA is very sensitive to GnHCl but somewhat resistant to temperature and the domain specific unfolding proceeds in an altered way as compared to the overall unfolding of HSA. While the overall denaturation of HSA is a two-state process for both GnHCl and heat, domain-III adopts two intermediate states for GnHCl induced denaturation and one intermediate state for temperature induced denaturation. Fluorescence correlation spectroscopic investigation divulges the conformational dynamics of domain-III of HSA in the native, intermediates and denatured state.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208 016, UP, India.
authors.forename: Bhaswati
authors.initials: B
authors.lastname: Sengupta
authors.affiliation: Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208 016, UP, India.
authors.forename: Nilimesh
authors.initials: N
authors.lastname: Das
authors.affiliation: Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208 016, UP, India. Electronic address: psen@iitk.ac.in.
authors.forename: Pratik
authors.initials: P
authors.lastname: Sen
mesh_terms: D005456:Fluorescent Dyes; D019791:Guanidine / Q000494:pharmacology; D006358:Hot Temperature; D006801:Humans; D011487:Protein Conformation / Q000187:drug effects / Q000528:radiation effects; D011489:Protein Denaturation / Q000187:drug effects / Q000528:radiation effects; D000072417:Protein Domains; D058767:Protein Unfolding / Q000187:drug effects / Q000528:radiation effects; D012709:Serum Albumin / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013696:Temperature
chemical_list: D005456:Fluorescent Dyes; D012709:Serum Albumin; D019791:Guanidine
keywords: Chemical denaturation; Conformational fluctuation dynamics; Fluorescence correlation spectroscopy; Human serum albumin; Protein domain; Thermal denaturation