title: Solid-state NMR investigation of the buried X-proline peptide bonds of bacteriorhodopsin.
abstract: The role of proline residues in the photocycle of bacteriorhodopsin (bR) is addressed using solid-state NMR. (13)C and (15)N chemical shifts from X-Pro peptide bonds in bR are assigned from REDOR difference spectra of pairwise labeled samples, and correlations of chemical shifts with structure are explored in a series of X-Pro model compounds. Results for the three membrane-embedded X-Pro bonds of bR indicate only slight changes in the transition from the resting state of the protein to either the early or late M state of the protonmotive photocycle. These results suggest that the buried prolines serve a principally structural role in bR.
authors.affiliation: Department of Chemistry and Center for Magnetic Resonance, Francis Bitter Magnet Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA.
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Lansing
authors.forename: Jingui G
authors.initials: JG
authors.lastname: Hu
authors.forename: Marina
authors.initials: M
authors.lastname: Belenky
authors.forename: Robert G
authors.initials: RG
authors.lastname: Griffin
authors.forename: Judith
authors.initials: J
authors.lastname: Herzfeld
mesh_terms: D001436:Bacteriorhodopsins / Q000737:chemistry*; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D009842:Oligopeptides / Q000737:chemistry; D010777:Photochemistry; D011392:Proline / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D009842:Oligopeptides; D001436:Bacteriorhodopsins; D011392:Proline