Files and links (1)
Accepted (AM)Open Access (License Unspecified), Open
Journal article
Cryoprotection of lipid membranes for high-resolution solid-state NMR studies of membrane peptides and proteins at low temperature
Journal of biomolecular NMR, v 59(4), 263
01 Aug 2014
PMID: 25015530
Featured in Collection : UN Sustainable Development Goals @ Drexel
Abstract
Solid-state NMR spectra of membrane proteins often show significant line broadening at cryogenic temperatures. Here we investigate the effects of several cryoprotectants to preserve the spectral resolution of lipid membranes and membrane peptides at temperatures down to similar to 200 K. Trehalose, glycerol, dimethylsulfoxide (DMSO), dimethylformamide (DMF), and polyethylene glycol (PEG), were chosen. These compounds are commonly used in protein crystallography and cryobiology. C-13 and H-1 magic-angle-spinning spectra of several types of lipid membranes show that DMSO provides the best resolution enhancement over unprotected membranes and also best retards ice formation at low temperature. DMF and PEG-400 show slightly weaker cryoprotection, while glycerol and trehalose neither prevent membrane line broadening nor prevent ice formation under the conditions of our study. Neutral saturated-chain phospholipids are the most amenable to cryoprotection, whereas negatively charged and unsaturated lipids attenuate cryoprotection. C-13-H-1 dipolar couplings and P-31 chemical shift anisotropies indicate that high spectral resolution at low temperature is correlated with stronger immobilization of the lipids at high temperature, indicating that line narrowing results from reduction of the conformational space sampled by the lipid molecules at high temperature. DMSO selectively narrowed the linewidths of the most disordered residues in the influenza M2 transmembrane peptide, while residues that exhibit narrow linewidths in the unprotected membrane are less impacted. A relatively rigid beta-hairpin antimicrobial peptide, PG-1, showed a linewidth increase of similar to 0.5 ppm over a similar to 70 K temperature drop both with and without cryoprotection. Finally, a short-chain saturated lipid, DLPE, exhibits excellent linewidths, suggesting that it may be a good medium for membrane protein structure determination. The three best cryoprotectants found in this work-DMSO, PEG, and DMF-should be useful for low-temperature membrane-protein structural studies by SSNMR without compromising spectral resolution.
Metrics
Details
- Title
- Cryoprotection of lipid membranes for high-resolution solid-state NMR studies of membrane peptides and proteins at low temperature
- Creators
- Myungwoon Lee - Iowa State UniversityMei Hong - Iowa State University
- Publication Details
- Journal of biomolecular NMR, v 59(4), 263
- Publisher
- Springer Nature
- Number of pages
- 15
- Grant note
- R01GM066976 / NATIONAL INSTITUTE OF GENERAL MEDICAL SCIENCES; United States Department of Health & Human Services; National Institutes of Health (NIH) - USA; NIH National Institute of General Medical Sciences (NIGMS) GM066976; GM088204 / NIH; United States Department of Health & Human Services; National Institutes of Health (NIH) - USA
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Chemistry
- Web of Science ID
- WOS:000339909200006
- Scopus ID
- 2-s2.0-84905017488
- Other Identifier
- 991021229902404721
UN Sustainable Development Goals (SDGs)
This publication has contributed to the advancement of the following goals:
InCites Highlights
Data related to this publication, from InCites Benchmarking & Analytics tool:
- Web of Science research areas
- Biochemistry & Molecular Biology
- Spectroscopy