Structural studies of the Na+/Ca2+ exchanger and of proteins from the Zika virus by Nuclear Magnetic Resonance spectroscopy in solution

Abstract

The aim of this proposal is to study structural and mechanistic aspects of the Na+/Ca2+ exchanger (NCX) by solution NMR spectroscopy. The NCX is one of the main mechanisms for the extrusion of intracellular Ca2+ in cardiac cells. Besides transporting Na+ and Ca2+, the NCX is regulated by these ions. The NCX is a large protein (950 amino acids), consisted of transmembrane and cytosolic domains connected by disordered regions. This multifaceted character makes the structural characterization of the NCX a difficult task. Thus, it is not surprising that the mechanism of the NCX allosteric regulation remains unclear. Based on NMR studies of the cytosolic domains of the exchanger from Drosophila melanogaster, CALX, we have recently proposed a mechanistic model for the allosteric regulation of the NCX and the CALX (Abiko et al., 2016). Here we plan to continue these studies in order to test different aspects of our model, and to tackle the transmembrane domain of the exchanger. In addition, this proposal focuses on structural studies of proteins from the Zika virus. Of particular interest are the envelope glycoprotein E, the NS2B-NS3pro protease and the intriguing NS1. These proteins play pivotal roles in the mechanisms of virus entry and replication. For this reason they are important targets for the development of antiviral compounds. We expect to produce samples in order to carry out fragment screening using saturation transfer NMR techniques (STD). It is expected that these studies will contribute to a better understanding of the biology and pathogenesis of this virus, and hence, to the development of antiviral compounds in the future. (AU)