Multiple physical techniques to structurally characterize biological relevant membranes and its interactions

• Grant number: 21/01593-1
• Support type: Regular Research Grants
• Duration: June 01, 2021 - May 31, 2023
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal researcher: Maria Teresa Moura Lamy
• Grantee: Maria Teresa Moura Lamy
• Home Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Assoc. researchers: Erix Alexander Milán Garcés ; Evandro Luiz Duarte ; Julio Henrique Kravcuks Rozenfeld

Abstract

In the last many years, we have focused on the study of structural properties of amphiphilic dispersions, and its interactions with biomolecules. Accordingly, we built up a rather well-equipped laboratory, with the appropriate physical techniques, mostly financed by FAPESP. The present proposal is concerned about fundamental studies, but also focuses on the better understanding of the biological activity of the systems under study, the structure-activity relationship, aiming at the development of new drugs and vaccines. We propose the continuity of different subjects where we have contributed, but where there are still many interesting opened questions. In the last years we significantly contributed to the understanding of anionic lipid dispersions. But we still need to finish the discussion about dispersions of dimyristoyl phosphatidyl glycerol, as we have new evidences that contradict models proposed in the literature. Our studies with the fluorescent probes Prodan and Laurdan brought important contributions to the understanding of the localization of these probes in cationic membranes of DODAB. We also brought to the literature a new proposal for the origin of the two fluorescent bands of the probes in simple solvents. Now, we intend to continue this study, both experimental and theoretical, focusing on the fluorescent properties of the probes in different membrane systems, to help on the interpretation of their fluorescent spectra in biological relevant model membranes. Considering that the cationic lipid DODAB is an immunogenic agent, we propose the structural study of mixed dispersions of DODAB and lysophosphatidyl colines, the latter also known to be able to modulate the immune system. Still in collaboration with biologists and biochemists, we intend to study the structural alterations caused by a few biomolecules on models of cell membrane: antraquinones, the protein crotoxin, antimicrobial peptides and fluoroquinolones. Our final goal is a better understanding of the mechanisms of action of these molecules. (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)

MARQUEZIN, CASSIA A.; TERESA LAMY, M.; DE SOUZA, EDUARDO S. Molecular collisions or resonance energy transfer in lipid vesicles? A methodology to tackle this question. JOURNAL OF MOLECULAR LIQUIDS, v. 341, NOV 1 2021. Web of Science Citations: 0.