High-resolution solid state sup 13 C NMR of bacteriorhodopsin: Characterization of (4- sup 13 C)asp resonances

Journal Article · Tue Jan 21 00:00:00 EST 1992 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00117a022· OSTI ID:5688067

Metz, G; Siebert, F ^[1]; Engelhard, M ^[2]

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1. Inst. fuer Biophysik und Strahlenbiologie der Universitaet, Freiburg (West Germany) Max-Planck-Inst. fuer Biophysik, Frankfurt (West Germany)
2. Max-Planck-Inst. fuer Ernaehrungsphysiologie, Dortmund (West Germany)

Solid state {sup 13}C nuclear magnetic resonance measurements of bacteriorhodopsin labeled with (4-{sup 13}C)Asp show that resonances of single amino acids can be resolved. In order to assign and characterize the resonances of specific Asp residues, three different approaches were used. (1) Determination of the chemical shift anisotropy from side-band intensities provides information about the protonation state of Asp residues; (2) relaxation studies and T{sub 1} filtering allow one to discriminate between resonances with different mobility; (3) a comparison of the spectra of light- and dark-adapted bacteriorhodopsin provides evidence for resonances from aspartic acid residues in close neighborhood of the chromophore. In agreement with other investigations, four resonances are assigned to internal residues. Two of them are protonated in the ground state up to pH 10 (Asp{sub 96} and Asp{sub 115}). All other detected resonance, including Asp{sub 85} and Asp{sub 212}, are due to deprotonated aspartic acid. Two lines due to the two internal deprotonated groups change upon dark and light adaptation, whereas the protonated Asp residues are unaffected.

• OSTI ID: 5688067
• Journal Information: Biochemistry; (United States), Vol. 31:2; ISSN 0006-2960
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ASPARTIC ACID
NUCLEAR MAGNETIC RESONANCE
RHODOPSIN
MOLECULAR STRUCTURE
CARBON 13
PHOTOSYNTHETIC BACTERIA
PHOTOSYNTHETIC MEMBRANES
RETINA
AMINO ACIDS
BODY
BODY AREAS
CARBON ISOTOPES
CARBOXYLIC ACIDS
EVEN-ODD NUCLEI
EYES
FACE
HEAD
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MEMBRANES
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
PIGMENTS
PROTEINS
RESONANCE
SENSE ORGANS
STABLE ISOTOPES
550201* - Biochemistry- Tracer Techniques