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Investigation of DMSO‐Induced Conformational Transitions in Human Serum Albumin Using Two‐Dimensional Raman Optical Activity Spectroscopy
Author(s) -
Batista Andrea N. L.,
Batista João M.,
Ashton Lorna,
Bolzani Vanderlan S.,
Furlan Maysa,
Blanch Ewan W.
Publication year - 2014
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/chir.22351
Subject(s) - polyproline helix , chemistry , raman optical activity , raman spectroscopy , dimethyl sulfoxide , helix (gastropod) , human serum albumin , circular dichroism , conformational change , protein secondary structure , crystallography , stereochemistry , biochemistry , molecule , organic chemistry , peptide , ecology , physics , snail , optics , biology
Recent Raman and Raman optical activity (ROA) results have demonstrated that dimethyl sulfoxide (DMSO) induces the selective conversion of α‐helix motifs into the poly(L‐proline) II (PPII) helix conformation in an array of proteins, while β‐sheets remain mostly unaffected. Human serum albumin (HSA), a highly α‐helical protein, underwent the most dramatic changes and, therefore, was selected as a model for further investigations into the mechanism of this conformational change. Herein we report the use of two‐dimensional ROA correlation analysis applying synchronous, autocorrelation, and moving windows approaches in order to understand the conformational transitions in HSA as a function of DMSO concentration. Our results indicate that the destabilization of native α‐helix starts at DMSO concentrations as little as 20% in water (v/v), with the transition to PPII helix being complete at ~80% DMSO. These results clearly indicate that any protein preparation containing relatively low concentrations of DMSO should consider possible disruptions in α‐helical domains. Chirality 26:497–501, 2014 . © 2014 Wiley Periodicals, Inc.