Solubilization of model membranes of different compositions by the detergent Triton X-100

• Grant number: 13/20499-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: January 01, 2014
• End date: May 31, 2015
• Field of knowledge: Biological Sciences - Biophysics - Molecular Biophysics
• Principal Investigator: Karin Do Amaral Riske
• Grantee: Bruno Mattei
• Host Institution: Escola Paulista de Medicina (EPM). Universidade Federal de São Paulo (UNIFESP). Campus São Paulo. São Paulo , SP, Brazil

Abstract

Detergents are amphiphilic molecules widely used as solubilizing agents of biological membranes. However, biological membranes treated with detergents exhibit insoluble fragments rich in sphingolipids and cholesterol. Due to the similarities in composition and characteristics, these fragments have been associated with lipid rafts and the liquid-ordered phase. Here, we propose a study of the physical-chemical aspects that govern the solubilization process of mimetic model membranes: lipid vesicles with controlled composition (binaries and ternaries lipid mixtures, mainly composed of POPC, SM and cholesterol). Different technics will be used to study the solubilization process of lipid vesicles by the detergent TX-100, one of the most used detergents in biological membrane solubilization protocols. The thermodynamic aspects of the detergent-lipid interaction will be investigated with isothermal titration calorimetry; the size of the structures formed during the solubilization will be obtained by turbidimetry and static and/or dynamic light scattering; the solubilization process of giant vesicles will be followed by optical microscopy; the possible interference of the detergent in the phase transition of lipids will be investigated by kinetics of a fluorescent probe leakage. In this project, different lipid compositions will be investigated in order to access information about the factors that influence the obtention of detergent resistant membrane fragments. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

MATTEI, BRUNO; LIRA, RAFAEL B.; PEREZ, KATIA R.; RISKE, KARIN A.. Membrane permeabilization induced by Triton X-100: The role of membrane phase state and edge tension. Chemistry and Physics of Lipids, v. 202, p. 28-37, JAN 2017. (13/20499-0, 11/22171-6)