Structural characterisation of lipoproteins

• Grant number: 18/07340-5
• Support type: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): July 01, 2018
• Effective date (End): June 30, 2020
• Field of knowledge: Physical Sciences and Mathematics - Physics
• Principal Investigator: Antonio Martins Figueiredo Neto
• Grantee: Zahra Lotfollahi
• Home Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 16/24531-3 - Structural and biophysics properties of native and modified lipoproteins, AP.TEM

Abstract

Lipoproteins are essential biological structures for metabolism. They are divided into several classes depending on their size and density: VLDL (Very Low Density Lipoproteins), LDL (Low Density Lipoproteins), HDL (High Density Lipoproteins). These structures, typically of tens of nanometers, have several biological functions, one of the main ones being cholesterol transport, which is insoluble in aqueous medium, in the circulatory system. The quantification of LDL and HDL in the body, among other lipid indicators, is used as an indicator of the health of the individual. In addition, it is known that oxidation of LDL is related to the formation of atherosclerotic plaques, which in turn can lead to heart disease. Recently we have presented methodologies and protocols of analysis and modeling for X-ray scattering data at low angles and nonlinear lipoprotein optical experiments in solution for various medium conditions (oxidation levels, temperature, etc.). This approach, which is innovative in the literature, allows the obtaining of detailed structural information about these structures as well as indications of changes induced by oxidation. In this project we intend to optimize experimental data analysis and modeling data from the Z-scan (non-linear optical technique) in the millisecond time scale in order to allow the structural characterization of lipoproteins and their states of modification/aggregation. This aggregation, which can be induced by levels of oxidation, temperature or other agents, can serve as an indicator of atherosclerotic plaque formation processes in real systems. (AU)