MSc Thesis Presentation: Paramagnetic Relaxation Enhancement: a method for Membrane Protein Structure Determination, and Triangulation of a Tightly Bound Lipid on its surface by Solid-State NMR

MSc Candidate

Raoul Vaz

Abstract

Magic angle spinning solid-state nuclear magnetic resonance (MAS ssNMR) is well suited for protein structure determination, as it both provides a native-like environment for membrane proteins to be studied in, and allows for the extraction of distance information between nuclear spins at an atomic level. When utilized with Paramagnetic Relaxation Enhancement (PRE), the high level of spectral ambiguity often observed with proteins may be alleviated, and an additional set of unambiguous internuclear distances may be obtained. In this study, it has been shown that a high-quality structure of a membrane protein, Anabaena Sensory Rhodopsin (ASR), may be determined through ssNMR alone, beginning with a PRE-based structure template which is used in an iterative process of cross-peak assignment and simulated annealing. Furthermore, it was demonstrated that PREs may be used for the triangulation of the highly mobile headgroup of a glycolipid tightly bound to ASR, revealing a precise binding location in the ASR trimer.