These authors contributed equally to this study.
19F-MAS NMR on Proteorhodopsin: Enhanced Protocol for Site-Specific Labeling for General Application to Membrane Proteins†
Article first published online: 13 JAN 2009
© 2009 U.S. Government. Journal Compilation. The American Society of Photobiology
Photochemistry and Photobiology
Volume 85, Issue 2, pages 535–539, March/April 2009
How to Cite
Hellmich, U. A., Pfleger, N. and Glaubitz, C. (2009), 19F-MAS NMR on Proteorhodopsin: Enhanced Protocol for Site-Specific Labeling for General Application to Membrane Proteins. Photochemistry and Photobiology, 85: 535–539. doi: 10.1111/j.1751-1097.2008.00498.x
This paper is part of the Proceedings of the 13th International Conference on Retinal Proteins, Barcelona, Spain, 15–19 June 2008.
- Issue published online: 25 FEB 2009
- Article first published online: 13 JAN 2009
- Received 14 August 2008, accepted 12 October 2008
Proteorhodopsin (PR) is a light-driven proton pump found in near-surface marine γ-proteobacteria. The green absorbing variant has three cysteines at positions 107, 156 and 175. We probed the accessibility of these residues by 19F-MAS NMR. For this purpose, an efficient but simple protocol for chemical fluorine labeling of accessible cysteines in membrane proteins was established. This one-step reaction was applied to detergent-solubilized PR before reconstitution into phospholipids. All three cysteines could be labeled and showed distinct 19F chemical shifts with different integral intensities. The accessibility of these cysteines is discussed in the context of a homology model. With the chemical cysteine labeling procedure shown here, an attractive option for site-directed solid-state NMR studies on other membrane proteins is offered due to the high intrinsic sensitivity of 19F-MAS NMR.