Electron magnetic resonance in studies of structure, function and interactions of biologically-relevant molecules

Abstract

Electron Magnetic Resonance (EMR) in its continuous wave (CW) regime has given a very diverse set of contributions when used in structural studies of biologically relevant systems. Such contributions include the characterization of metal binding sites in proteins, understanding molecular aspects of the dynamic structure of biological membranes, and studies of electron transfer processes and reaction mechanisms. More recently, EMR has experienced a significant growth in its use mainly due to the appearance of new CW-EMR methodologies, such as site-directed spin labeling techniques, as well to its extension to very high frequencies and to time-resolved methods. The applications of EMR to studies of structure and function of proteins, biomembranes, peptides, model molecules and their complexes with transition metal íons are the main goal to be achieved during the development of the present project. This grant proposal represents the congregation of several research fields of investigation developed in the Molecular Biophysics group at the IFSC/USP and that will be now implemented in the Physics Department of the FFCLRP/USP. The diversity of themes finds its intersection right at a very solid expertise in EMR use, which includes multifrequency, CW, and pulsed EMR), developed by our group in a recent past. More specifically, we can arrange the problems to be investigated in this Project as: (I) site-directed spin labeling of the enzyme chlorocatechol 1,2-dioxygenase and of a calcium-binding protein (S100A12); (II) interactions between low-molecular weight ligans and model membranes, specially peptides derived from a glycoprotein of the SARS vírus; (III) metal complexes of biological interest with focus on copper complexes with potential pharmacological application. (AU)