Single molecule fluorescence in biological membranes

• Grant number: 15/00672-4
• Support Opportunities: Research Grants - Visiting Researcher Grant - International
• Start date: May 25, 2015
• End date: May 29, 2015
• Field of knowledge: Biological Sciences - Biophysics - Molecular Biophysics
• Principal Investigator: Amando Siuiti Ito
• Grantee: Amando Siuiti Ito
• Visiting researcher: Akihiro Kusumi
• Visiting researcher institution: Kyoto University, Japan
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

The fluid mosaic model proposed that the lipid structuration as an essential for the biological activity of proteins immersed in the cell membrane. The model was improved taking into account the formation of specialized lipid domains as important structural factor for the membrane activity. Kusumi and collaborators proposed that the membrane is hierarchically organized in dynamic structures and it is important to understand the role of the inter-relations between the organized components of the membrane, and how do they affect the cell activity. Prof. Akihiro Kusumi, from the Institute for Frontier Medical Sciences, Kyoto University, was pioneer in the development of techniques to obtain images from fluorescence lifetime and of methods to observe and manipulate single molecules which were applied to study plasm membrane in living cells. In the fluorescence laboratory of the photobiophysics group of the Physics Department of Faculty of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo (DF-FFCLRP USP), we have experience in fluorescence spectroscopy, both in steady state as in time resolved techniques, applied to biophysics. More recently, it was acquired an equipment for measurements of fluorescence correlation spectroscopy and fluorescence lifetime imaging, within the "programa multiusuários" from FAPESP. Those techniques, applied to the study of biophysical problems, put in evidence the importance of micro-heterogeneities in lipid structures formed in model membranes. Furthermore it was also installed in the DF-FFCLRP the necessary infra-structure to develop projects devoted to the production of recombinant proteins, via heterologous expression. In this way, it is possible the study of molecular conditionings to interactions evolving proteins in membranes. Projects currently running in DF-FFCLRP will profit the collaboration with Prof. Kusumi, enlarging the possibilities of applications of fluorometric methods in biophysics. During the visit, Prof. Kusumi will contributes to studies using confocal microscopy, fluorescence correlation and lifetime fluorescence imaging techniques. Practical activities and general discussions will be performed, with the participation of researchers from several groups from FFCLRP and from other institutions doing research in related subjects. In addition, the important contribution of Prof. Kusumi shall be presented to the Brazilian researchers community, through a plenary lecture to be presented at the Encontro Nacional de Física da Matéria Condensada. (AU)