title: Anisotropy resolved multidimensional emission spectroscopy (ARMES): A new tool for protein analysis.
abstract: Structural analysis of proteins using the emission of intrinsic fluorophores is complicated by spectral overlap. Anisotropy resolved multidimensional emission spectroscopy (ARMES) overcame the overlap problem by the use of anisotropy, with chemometric analysis, to better resolve emission from different fluorophores. Total synchronous fluorescence scan (TSFS) provided information about all the fluorophores that contributed to emission while anisotropy provided information about the environment of each fluorophore. Here the utility of ARMES was demonstrated via study of the chemical and thermal denaturation of human serum albumin (HSA). Multivariate curve resolution (MCR) analysis of the constituent polarized emission ARMES data resolved contributions from four emitters: fluorescence from tryptophan (Trp), solvent exposed tyrosine (Tyr), Tyr in a hydrophobic environment, and room temperature phosphorescence (RTP) from Trp. The MCR scores, anisotropy, and literature validated these assignments and showed all the expected transitions during HSA unfolding. This new methodology for comprehensive intrinsic fluorescence analysis of proteins is applicable to any protein containing multiple fluorophores.
authors: Nanoscale Biophotonics Laboratory, School of Chemistry, National University of Ireland, Galway, Galway, Ireland.
authors: Radu Constantin
authors: RC
authors: Groza
authors: Nanoscale Biophotonics Laboratory, School of Chemistry, National University of Ireland, Galway, Galway, Ireland.
authors: Boyan
authors: B
authors: Li
authors: Nanoscale Biophotonics Laboratory, School of Chemistry, National University of Ireland, Galway, Galway, Ireland. Electronic address: alan.ryder@nuigalway.ie.
authors: Alan G
authors: AG
authors: Ryder
mesh_terms: D016880:Anisotropy; D005453:Fluorescence; D006801:Humans; D008958:Models, Molecular; D011489:Protein Denaturation; D058767:Protein Unfolding; D012709:Serum Albumin / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D014364:Tryptophan / Q000737:chemistry
chemical_list: D012709:Serum Albumin; D014364:Tryptophan
keywords: Anisotropy; Chemometrics; Fluorescence; Multidimensional; Protein; Unfolding