Thermal denaturation and aggregation of hemoglobin... - BV FAPESP
Advanced search
Start date
Betweenand
Related content
(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Thermal denaturation and aggregation of hemoglobin of Glossoscolex paulistus in acid and neutral media

Full text
Author(s):
Carvalho, Jose Wilson P. [1] ; Carvalho, Francisco A. O. [1] ; Santiago, Patricia S. [2, 1] ; Tabak, Marcel [1]
Total Authors: 4
Affiliation:
[1] Univ Sao Paulo, Inst Quim Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil
[2] Univ Estadual Paulista, Sao Paulo - Brazil
Total Affiliations: 2
Document type: Journal article
Source: International Journal of Biological Macromolecules; v. 54, p. 109-118, MAR 2013.
Web of Science Citations: 8
Abstract

The thermal denaturation and aggregation of the HbGp, in the oxy- and cyanomet-forms, was investigated by DSC, AUC, DLS, optical absorption and CD, in the pH range from 5.0 to 7.0. Oxy-HbGp has a denaturation process partially reversible and dependent on the temperature. DSC melting curve is characterized by a single peak with T-c value of 333.4 +/- 0.2 K for oxy-HbGp, while two peaks with T-c values of 332.2 +/- 0.1 and 338.4 +/- 0.2 K are observed for cyanomet-HbGp, at pH 7.0. In acidic pH oxy- and cyanomet-HbGp are more stable showing higher T-c values and aggregation. AUC data show that, HbGp, at pH 7.0, upon denaturation, remains undissociated at 323 K, presenting oligomeric dissociation at 333 (12 +/- 3% of tetramer and 88 +/- 5% of whole HbGp) and 343 K (70 +/- 5% of monomer and 30 +/- 2% of trimer). DLS data show that the lag period before aggregation is dependent on the temperature and HbGp concentration. Optical absorption and CD results show that the increase of temperature leads to the oxy-HbGp oxidation and aggregation, above 331 K, in acidic pH. CD data, for HbGp, present a greater thermal stability in acid medium than at neutral pH, with similar T-c values for both oxidation forms. Our data are consistent with previous studies and represents an advance in understanding the thermal stability of oligomeric HbGp structure. (c) 2012 Elsevier B.V. All rights reserved. (AU)

FAPESP's process: 09/17261-6 - Oligomeric stability studies of giant extracellular hemoglobin of Glossoscolex paulistus (HbGp) in the presence of chaotropic agents, surfactants and characterization of its subunits.
Grantee:Francisco Adriano de Oliveira Carvalho
Support Opportunities: Scholarships in Brazil - Doctorate
FAPESP's process: 10/09719-0 - Effects of surfactants, iron oxidation state and medium pH upon the thermal stability of giant extracellular hemoglobin of Glossoscolex paulistus in its native oligomeric form and for trimeric ABC and monomeric d globin subunits
Grantee:José Wilson Pires Carvalho
Support Opportunities: Scholarships in Brazil - Doctorate