Record Details

Biophysical analysis of partially folded state of alpha-lactalbumin in the presence of cationic and anionic surfactants

DSpace at IIT Bombay

View Archive Info
 
 
Field Value
 
Title Biophysical analysis of partially folded state of alpha-lactalbumin in the presence of cationic and anionic surfactants
 
Creator MISRA, PP
KISHORE, N
 
Subject MOLTEN-GLOBULE STATE
INTRINSICALLY UNSTRUCTURED PROTEINS
SODIUM DODECYL-SULFATE
LIGHT-SCATTERING
CYTOCHROME-C
FOLDING THERMODYNAMICS
HYDROPHOBIC BONDS
COLD DENATURATION
ALKYL SULFATES
LOW PH
alpha-LA
Molten globule
Electrostatic interaction
Hydrophobic interaction
zeta-Potential
Hydrodynamic diameter
 
Description The role of different types of interactions and their contribution in the stabilization of bovine alpha-lactalbumin (alpha-LA) molten globule in presence of cationic surfactant, hexadecyl trimethyl ammonium bromide (HTAB) and anionic surfactant, sodium dodecyl sulphate (SDS) have been examined using a combination of spectroscopic, light scattering and calorimetric techniques. The results correlated well with each other and were used to characterize the partially folded states of the protein both qualitatively and quantitatively. At lower concentration of the surfactants, the thermodynamic parameters obtained from UV-visible spectroscopy suggested an increased exposure of non-polar groups in HTAB while a possible restructuring of non-polar groups were indicated in SOS. The fluorescence and circular dichroism spectroscopy showed the formation of an intermediate state at various concentrations of HTAB and SDS while the lifetime measurements supported the assumption of protein-surfactant complex stability in HTAB as compared to SOS. The hydrodynamic diameter and the zeta-potential were analyzed by dynamic light scattering (DLS) which also implicated the combined influence of electrostatic and hydrophobic interactions in protein unfolding in HTAB and only hydrophobic interactions in SDS. The binding parameters for ANS obtained from isothermal titration calorimetric (ITC) measurements suggested a high stability of alpha-LA molten globule and the role of enthalpic and entropic contribution in the binding of ANS in HTAB. It also indicated the fragility of alpha-LA molten globule in SDS. The possible binding sites as well as the interactions of ANS with the partially folded protein were also studied from the thermodynamic parameters obtained from the ITC. (C) 2010 Elsevier Inc. All rights reserved.
 
Publisher ACADEMIC PRESS INC ELSEVIER SCIENCE
 
Date 2012-06-26T07:11:01Z
2012-06-26T07:11:01Z
2011
 
Type Article
 
Identifier JOURNAL OF COLLOID AND INTERFACE SCIENCE,354(1)234-247
0021-9797
http://dx.doi.org/10.1016/j.jcis.2010.10.015
http://dspace.library.iitb.ac.in/jspui/handle/100/14101
 
Language English