Location of the chromophore in bacteriorhodopsin

Journal Article · Fri Aug 01 04:00:00 EDT 1980 · Proc. Natl. Acad. Sci. U.S.A.; (United States)

DOI:https://doi.org/10.1073/pnas.77.8.4726· OSTI ID:6868945

King, G I ^[1]; Mowery, P C; Stoeckenius, W; Crespi, H L; Schoenborn, B P

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1. Univ. of California, San Francisco

We present a location for the retinylidene chromophore in dark-adapted bacteriorhodopsin based on the differences in neutron scattering between purple membrane preparations reconsitituted with retinal and with deuterated retinal. The Fourier difference density map contains more peaks than expected, and additional arguments are introduced to exclude artificial peaks caused by the reconstitution techniques or the limited resolution of the diffraction data. The membrane preparation used is necessarily dark-adapted and therefore contains 13-cis- and all-trans-retinal isomers in roughly equal amounts. However, we find only a single position for both isomers. Presumably, the difference in conformation caused by isomerization around the C13-C14 double bond is minimized by rotation around other bonds. The retinal is located between ..cap alpha..-helical segments of the protein and its nearest neighbor (intratrimer) distance is 26 A; the next-nearest neighbor (intertrimer) distance is 38A.

• OSTI ID: 6868945
• Journal Information: Proc. Natl. Acad. Sci. U.S.A.; (United States), Journal Name: Proc. Natl. Acad. Sci. U.S.A.; (United States) Vol. 77:8; ISSN PNASA
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
550700 -- Microbiology
59 BASIC BIOLOGICAL SCIENCES
BIOCHEMISTRY
CELL CONSTITUENTS
CELL MEMBRANES
CHARGED-PARTICLE TRANSPORT
CHEMICAL REACTIONS
CHEMISTRY
IMINES
ISOMERS
MEMBRANES
MOLECULAR BIOLOGY
MOLECULAR STRUCTURE
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PROTEINS
PROTON TRANSPORT
RADIATION TRANSPORT
SCHIFF BASES