Solid-State NMR Derived Structure: Backbone of Influenza A M2 Protein

Florida State University, Tallahassee FL

Investigators

Abstract

Cross MCB 9986036 The objective of this research is to develop a novel approach to membrane protein structural characterization by solid state NMR without the need for resonance assignments. This is due to the recent observation of resonance patterns in PISEMA (15N-1H dipolar - 15N chemical shift) spectra. By a combination of uniform 15N labeling and amino acid specific labeling, both the tilt and rotational orientation of transmembrane helices can be obtained. While this represents an exciting development for obtaining an early structural image, a combination of distance and assigned orientational constraints will still be important for gleaning the full potential from the solid state NMR-derived constraints. The optimal utilization of these constraints is being aided by a detailed mathematical analysis of helices and helical bundles. Through refinement against all of the structural constraints and the CHARMM energy, it is possible to achieve a very high resolution structure. Cross-validation will be used to assess the relative weights in the experimental and energetic parameters for these refinements.