Batista, Andrea N. L. [UNESP]Batista, Joao M. [UNESP]Ashton, LornaBolzani, Vanderlan da Silva [UNESP]Furlan, Maysa [UNESP]Blanch, Ewan W.2015-03-182015-03-182014-09-01Chirality. Hoboken: Wiley-blackwell, v. 26, n. 9, p. 497-501, 2014.0899-0042http://hdl.handle.net/11449/116181Recent Raman and Raman optical activity (ROA) results have demonstrated that dimethyl sulfoxide (DMSO) induces the selective conversion of alpha-helix motifs into the poly(L-proline) II (PPII) helix conformation in an array of proteins, while beta-sheets remain mostly unaffected. Human serum albumin (HSA), a highly alpha-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 alpha-helix starts at DMSO concentrations as little as 20% in water (v/v), with the transition to PPII helix being complete at similar to 80% DMSO. These results clearly indicate that any protein preparation containing relatively low concentrations of DMSO should consider possible disruptions in alpha-helical domains. (C) 2014 Wiley Periodicals, Inc.497-501engROA2DCOSHSAmoving windowsproteinsecondary structurePPII helixArtigo10.1002/chir.22351WOS:000343295600011Acesso restrito44840836852516731308042794786872