Rotationally Aligned Membrane Mimetics for Studies of Ligand Binding to Membrane Proteins By Oriented-Sample NMR
Abstract
Membrane proteins (MPs) perform vast variety of important biological functions and constitute about 50% of modem drug targets aimed at treating a broad spectrum of diseases such as cancer, diabetes, and neurological disorders. However, the number of the solved MP structures remains scarce. Notably, in most cases these structures have been determined at cryogenic temperatures and/or at extremely low lipid-to-protein ratios by X-ray crystallography and cryo-electron microscopy. By contrast, solid-state nuclear magnetic resonance (NMR) has become a powerful experimental technique for structure determination of MPs in their native-like membrane environments (i.e. physiological temperature, full hydration and high lipid concentration). To advance the technique of solid-state NMR of oriented samples for large multihelical MPs, highly uniform peptide- and polymer-based nanodiscs (macrodiscs) will be utilized to mimic the native lipid environment for the protein of interest without the use of detergents. The new discoidal mimetics will be applied to detect ligand binding to human nicotinic Acetylcholine receptor (nAchR) protein, which is implicated in various neurological disorders. Experimental and computational methods will be developed for measuring angular-dependent dipolar couplings within the protein backbone and using them as restraints for structure calculations. An important step forward will be the development of experimental NMR methods for extracting angular restraints from uniformly, (13C, 15N)-doubly labeled membrane proteins. New computational algorithms for structure calculations using the angular restraints and their validation by bioinformatics tools will be also developed. The proposed research is relevant to several aspects of Soldier s health and survival. The developed macrodiscs can potentially be used for incorporating receptors for rapid antibody screening and used as building blocks in advanced material applications. Moreover, functionalized lipodiscs can be incorporated into blood stream for injection of hydrophobic analgesics. Finally, the nicotinic Acetylcholine receptors to be studied in this project are implicated in neurological and post-traumatic stress disorders.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 14, 2019
- Source ID
- W911NF1810363
Entities
People
- Alexander A Nevzorov
Organizations
- Army Contracting Command
- North Carolina State University
- United States Army