High-resolution sup 13 C NMR study of the topography and dynamics of methionine residues in detergent-solubilized bacteriorhodopsin

Journal Article · Tue Apr 23 00:00:00 EDT 1991 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00230a012· OSTI ID:5556414

Seigneuret, M; Neumann, J M; Levy, D; Rigaud, J L ^[1]

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1. URA-CNRS, Gif-sur-Yvette (France)

The proton transport membrane protein bacteriorhodopsin has been biosynthetically labeled with (methyl-{sup 13}C)methionine and studied by high-resolution {sup 13}C NMR after solubilization in the detergent Triton X-100. The nine methionine residues of bacteriorhodopsin give rise to four well-resolved {sup 13}C resonances, two of which are shifted upfield or downfield due to nearby aromatic residues. Methionine residues located on the hydrophilic surfaces, on the hydrophobic surface, and in the interior of the protein could be discriminated by studying the effects of papain proteolysis, glycerol-induced viscosity increase, and paramagnetic broadening by spin-labels on NMR spectra. Such data were used to evaluate current models of the bacteriorhodopsin transmembrane folding and tertiary structure. T{sub 2} and NOE measurements were performed to study the local dynamics of methionine residues in bacteriorhodopsin. For the detergent-solubilized protein, hydrophilic and hydrophobic external residues undergo a relatively large extent of side chain wobbling motion while most internal residues are less mobile. In the native purple membrane and in reconstituted bacteriorhodopsin liposomes, almost all methionine residues have their wobbling motion severely restricted, indicating a large effect of the membrane environment on the protein internal dynamics.

• OSTI ID: 5556414
• Journal Information: Biochemistry; (United States), Vol. 30:16; ISSN 0006-2960
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
MEMBRANE PROTEINS
STRUCTURAL MODELS
METHIONINE
NUCLEAR MAGNETIC RESONANCE
CARBON 13
LIPOSOMES
PAPAIN
PHOTOSYNTHETIC BACTERIA
RHODOPSIN
TOPOGRAPHY
AMINO ACIDS
CARBON ISOTOPES
CARBOXYLIC ACIDS
DRUGS
ENZYMES
EVEN-ODD NUCLEI
HYDROLASES
ISOTOPES
LIGHT NUCLEI
LIPOTROPIC FACTORS
MAGNETIC RESONANCE
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PEPTIDE HYDROLASES
PIGMENTS
PROTEINS
RESONANCE
SH-PROTEINASES
STABLE ISOTOPES
550601* - Medicine- Unsealed Radionuclides in Diagnostics