You are in the accessibility menu

Please use this identifier to cite or link to this item: http://acervodigital.unesp.br/handle/11449/74173
Title: 
Urea-induced unfolding of Glossoscolex paulistus hemoglobin, in oxy- and cyanomet-forms: A dissociation model
Author(s): 
Institution: 
  • Universidade de São Paulo (USP)
  • Universidade Estadual Paulista (UNESP)
ISSN: 
  • 0141-8130
  • 1879-0003
Abstract: 
The urea effect on the giant extracellular hemoglobin of Glossoscolex paulistus (HbGp) stability was studied by analytical ultracentrifugation (AUC) and small angle X-ray scattering (SAXS). AUC data show that the sedimentation coefficient distributions curves c (S), at 1.0mol/L of urea, display a single peak at 57 S, associated to the undissociated protein. The increase in urea concentration, up to 4.0mol/L, induces the appearance of smaller species, due to oligomeric dissociation. The sedimentation coefficients and molecular masses are 9.2S and 204kDa for the dodecamer (abcd)3, 5.5S and 69kDa for the tetramer (abcd), 4.1S and 52kDa for the trimer (abc) and 2.0 S and 17kDa for the monomer d, respectively. SAXS data show initially a decrease in the I(0) values due to the oligomeric dissociation, and then, above 4.0mol/L of denaturant, for oxy-HbGp, and above 6.0mol/L for cyanomet-HbGp, an increase in the maximum dimension and gyration radius is observed, due to the unfolding process. According to AUC and SAXS data the HbGp unfolding is described by two phases: the first one, at low urea concentration, below 4.0mol/L, characterizes the oligomeric dissociation, while the second one, at higher urea concentration, is associated to the unfolding of dissociated species. Our results are complementary to a recent report based on spectroscopic observations. © 2012 Elsevier B.V.
Issue Date: 
1-Jan-2013
Citation: 
International Journal of Biological Macromolecules, v. 52, n. 1, p. 340-348, 2013.
Time Duration: 
340-348
Keywords: 
  • AUC
  • Extracellular hemoglobin
  • HbGp
  • Oligomeric dissociation
  • SAXS
  • Urea
  • cyanomethemoglobin
  • hemoglobin
  • oxyhemoglobin
  • unclassified drug
  • urea
  • annelid
  • concentration response
  • dissociation
  • Glossoscolex paulistus
  • molecular weight
  • nonhuman
  • oligomeric dissociation
  • protein stability
  • protein structure
  • protein unfolding
  • sedimentation
  • ultracentrifugation
  • X ray crystallography
  • Animals
  • Hemoglobins
  • Models, Chemical
  • Oligochaeta
  • Protein Folding
  • Glossoscolex
Source: 
http://dx.doi.org/10.1016/j.ijbiomac.2012.09.023
URI: 
Access Rights: 
Acesso aberto
Type: 
outro
Source:
http://repositorio.unesp.br/handle/11449/74173
Appears in Collections:Artigos, TCCs, Teses e Dissertações da Unesp

There are no files associated with this item.
 

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.