Title: MOLECULAR FEATURES OF NONIONIC DETERGENTS INVOLVED IN THE BINDING KINETICS AND SOLUBILIZATION EFFICIENCY, AS STUDIED IN MODEL (LANGMUIR FILMS) AND BIOLOGICAL (ERYTHROCYTES) MEMBRANES
Author: Casadei, Bruna Renata; Domingues, Cleyton Crepaldi; Clop, Eduardo M.; Couto, Verônica Muniz; Perillo, Maria Angelica; Paula, Eneida De
Is part of: COLLOIDS AND SURFACES B-BIOINTERFACES, v. 166, p. 152 - 160
Citation: Casadei, Bruna Renata; Domingues, Cleyton Crepaldi; Clop, Eduardo M.; Couto, Verônica Muniz; Perillo, Maria Angelica; Paula, Eneida De; MOLECULAR FEATURES OF NONIONIC DETERGENTS INVOLVED IN THE BINDING KINETICS AND SOLUBILIZATION EFFICIENCY, AS STUDIED IN MODEL (LANGMUIR FILMS) AND BIOLOGICAL (ERYTHROCYTES) MEMBRANES. COLLOIDS AND SURFACES B-BIOINTERFACES, v.166, p. 152-160, 2018
Abstract: The effect of the nonionic detergents Brij-98 and Brij-58 over human erythrocytes was studied through quantitative hemolysis and in Langmuir films. Hemolytic tests revealed that Brijs are stronger membrane solubilizers than Triton X-100 (TX-100), with effective detergent/lipid ratios of 0.18 and 0.37 for Brij-98 and Brij-58, respectively. Experiments with Langmuir films provided significant information on the kinetics and thermodynamics of detergent-membrane interaction. The adsorption (k(a)) and desorption (k(d)) rate constants of Brijs were lower than those of TX-100. In the case of k(a), that is probably due to their larger hydrophilic head (with twice (20) the oxyethylene units of TX-100). As for the thermodynamic binding constant, the linear and longer hydrophobic acyl chains of Brijs favor their stabilization in-between the lipids, through London van der Waals forces. Consequently, K-b,K-m values of Brij-98 (12,500 M-1) and Brij-58 (19,300 M-1) resulted higher than TX-100 (7500 M-1), in agreement with results from the hemolytic tests. Furthermore, Brij-58 binds with higher affinity than Brij-98 to bilayers and monolayers, despite its shorter (palmitic) hydrocarbon chain, showing that unsaturation restrains the detergent insertion into these environments. Our results provide significant information about the mechanism of interaction between Brijs and membranes, supporting their distinct solubilization effect. (C) 2018 Elsevier B.V. All rights reserved.
Keywords: detergents; erythrocytes; hemolysis; membranes; monolayers; solubilization;
Subjects: CIENCIAS_BIOLOGICAS; Biofísica de Processos e Sistemas; CIENCIAS_BIOLOGICAS; Bioquímica;
Funding: This work was supported by grants from cooperation between Capes (Brazil) and Mincyt, SeCyT-Universidad Nacional de Cordoba, CONICET and Foncyt (Argentina); and also from CNPq (# 479993/2011-4). EMC and MAP are career members of CONICET. BRC and EP acknowledge their fellowships from CAPES and CNPq (# 308621/2013-1), respectively.