On the interaction of bovine serum albumin (BSA) with cethyltrimethyl ammonium chloride surfactant: electron paramagnetic resonance (EPR) study

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Main Author:	Marcel Tabak
Format:	Artículo científico
Language:	en
Published:	Sociedade Brasileira de Física 2006
Subjects:	Física, Astronomía y Matemáticas EPR Bovine serum
Online Access:	Acceder al recurso
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_version_	1866812464249700352
author	Marcel Tabak
author_facet	Marcel Tabak
contents	On the interaction of bovine serum albumin (BSA) with cethyltrimethyl ammonium chloride surfactant: electron paramagnetic resonance (EPR) study Marcel Tabak Diógenes de Sousa Carlos Ernesto Garrido Salmon Física, Astronomía y Matemáticas EPR Bovine serum Electron paramagnetic resonance (EPR) has been used to monitor the interaction of bovine serum albumin(BSA) with cationic cethyltrimethylammonium chloride (CTAC) at pH 7.0. EPR results using 5-DSA and16-DSA nitroxide spin labels show that in the presence of BSA the EPR spectra are composed of two labelpopulations, one contacting the protein and a second one due to label localization in the micelles. Evidence isalso obtained for a competition of the surfactants with the spin labels for the high affinity binding sites of thestearic acid spin labels as monitored by changes in the fraction of the two label populations as the surfactantconcentration is increased. The effect of sodium dodecylsulfate (SDS) reported previously seems to be strongerin the sense that increase in SDS concentration leads to a complete transfer of spin label from close proteincontact sites to the micelles while for CTAC, apparently, a significant immobilization of probe remains even athigher surfactant concentrations. EPR gives information on the dynamics inside the protein-surfactant aggregatesand associated to label localization and motion. The dynamics of the nitroxide spin-labels bound to theprotein correlate to the stronger binding of SDS to BSA as compared to CTAC binding. Simulation of EPRspectra for spin labels in pure CTAC micelles, in pure protein or in protein-bound micelles show rotational correlationtimes similar to those obtained from the simple evaluation based on the intensities of nitrogen hyperfinecoupling components. Rotational correlation times obtained for 5-DSA bound to protein are larger as comparedto 16-DSA values suggesting greater mobility for the later even when bound to the protein. 2006 artículo científico 0103-9733 https://www.redalyc.org/articulo.oa?id=46436113 en http://www.redalyc.org/revista.oa?id=464 Brazilian Journal of Physics application/pdf Sociedade Brasileira de Física Brazilian Journal of Physics (Brasil) Num.1A Vol.36
format	Artículo científico
id	redalyc_46436113
language	en
publishDate	2006
publisher	Sociedade Brasileira de Física
spellingShingle	On the interaction of bovine serum albumin (BSA) with cethyltrimethyl ammonium chloride surfactant: electron paramagnetic resonance (EPR) study Marcel Tabak Física, Astronomía y Matemáticas EPR Bovine serum On the interaction of bovine serum albumin (BSA) with cethyltrimethyl ammonium chloride surfactant: electron paramagnetic resonance (EPR) study Marcel Tabak Diógenes de Sousa Carlos Ernesto Garrido Salmon Física, Astronomía y Matemáticas EPR Bovine serum Electron paramagnetic resonance (EPR) has been used to monitor the interaction of bovine serum albumin(BSA) with cationic cethyltrimethylammonium chloride (CTAC) at pH 7.0. EPR results using 5-DSA and16-DSA nitroxide spin labels show that in the presence of BSA the EPR spectra are composed of two labelpopulations, one contacting the protein and a second one due to label localization in the micelles. Evidence isalso obtained for a competition of the surfactants with the spin labels for the high affinity binding sites of thestearic acid spin labels as monitored by changes in the fraction of the two label populations as the surfactantconcentration is increased. The effect of sodium dodecylsulfate (SDS) reported previously seems to be strongerin the sense that increase in SDS concentration leads to a complete transfer of spin label from close proteincontact sites to the micelles while for CTAC, apparently, a significant immobilization of probe remains even athigher surfactant concentrations. EPR gives information on the dynamics inside the protein-surfactant aggregatesand associated to label localization and motion. The dynamics of the nitroxide spin-labels bound to theprotein correlate to the stronger binding of SDS to BSA as compared to CTAC binding. Simulation of EPRspectra for spin labels in pure CTAC micelles, in pure protein or in protein-bound micelles show rotational correlationtimes similar to those obtained from the simple evaluation based on the intensities of nitrogen hyperfinecoupling components. Rotational correlation times obtained for 5-DSA bound to protein are larger as comparedto 16-DSA values suggesting greater mobility for the later even when bound to the protein. 2006 artículo científico 0103-9733 https://www.redalyc.org/articulo.oa?id=46436113 en http://www.redalyc.org/revista.oa?id=464 Brazilian Journal of Physics application/pdf Sociedade Brasileira de Física Brazilian Journal of Physics (Brasil) Num.1A Vol.36
title	On the interaction of bovine serum albumin (BSA) with cethyltrimethyl ammonium chloride surfactant: electron paramagnetic resonance (EPR) study
topic	Física, Astronomía y Matemáticas EPR Bovine serum
url	https://www.redalyc.org/articulo.oa?id=46436113

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