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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Ionic surfactants-Glossoscolex paulistus hemoglobin interactions: Characterization of species in the solution

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Carvalho, Francisco A. O. ; Alves, Fernanda R. ; Tabak, Marcel
Total Authors: 3
Document type: Journal article
Source: International Journal of Biological Macromolecules; v. 92, p. 670-681, NOV 2016.
Web of Science Citations: 1

Glossoscolex paulistus hemoglobin (HbGp) is an oligomeric multisubunit protein with molecular mass of 3600 kDa. In the current study, the interaction of sodium dodecyl sulfate (SDS) and cetyl trimethylammonium chloride (CTAC) surfactants with the monomer d and the whole oxy-HbGp, at pH 7.0, was investigated. For pure monomer d solution, SDS promotes the dimerization of subunit d, and the monomeric and dimeric forms have sedimentation coefficient values, s(20,w), around 2.1-2.4 S and 2.9-3.2 S, respectively. Analytical ultracentrifugation (AUC) and isothermal titration calorimetry (ITC) data suggest that up to 26 DS- anions are bound to the monomer. In the presence of CTAC, only the monomeric form is observed in solution for subunit d. For the oxy-HbGp, SDS induces the dissociation into smaller subunits, such as, monomer d, trimer abc, and tetramer abcd, and unfolding without promoting the protein aggregation. On the other hand, lower CTAC concentration promotes protein aggregation, mainly of trimer, while higher concentration induces the unfolding of dissociated species. Our study provides strong evidence that surfactant effects upon the HbGp-subunits are different, and depend on the surfactant: protein concentration ratio and the charges of surfactant headgroups. (C) 2016 Elsevier B.V. All rights reserved. (AU)

FAPESP's process: 13/09829-8 - Biophysical and structural studies of extracellular hemoglobin of Glossoscolex paulistus, and its monomer d and dodecamer (abcd)3 subunits.
Grantee:Francisco Adriano de Oliveira Carvalho
Support type: Scholarships in Brazil - Post-Doctorate