Vibrational spectroscopy of cell membrane models by Sum-Frequency Generation (SFG spectroscopy)

• Grant number: 22/14488-4
• Support Opportunities: Scholarships in Brazil - Master
• Start date: May 01, 2023
• End date: January 31, 2025
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Paulo Barbeitas Miranda
• Grantee: Bruna Borges Freri
• Host Institution: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 14/50869-6 - INCT 2014: on Organic Electronics, AP.TEM

Abstract

Several cellular processes depend on the interaction of the membrane with molecules in the cytoplasm or in the extracellular medium. Therefore, the study of the structure of cell membranes and their interaction with other molecules is fundamental for advancing cell biology. To perform these in vitro studies, membrane mimetic models are frequently used, such as lipid vesicles, solid-supported lipid bilayers and Langmuir films. The latter are very versatile, and several techniques can be used to study Langmuir films, with vibrational spectroscopy by Sum-Frequency Generation (SFG spectroscopy) being a very powerful technique. This technique allows to obtain the vibrational spectrum of the interfacial molecules, as well as probing the average conformation of the hydrophobic chains, which depend on the packing of the lipid molecules. To date, the vast majority of studies by SFG spectroscopy have focused on Langmuir films of lipids with saturated chains. Therefore, the present project aims to understand the correlation between the SFG spectrum and the packing of these films involving more complex lipids (with unsaturated or branched chains, for example). Such a study will contribute to the extension of SFG spectroscopy to probe more realistic membrane models.