Time-resolved resonance Raman characterization of the bL/sub 550/ intermediate and the two dark-adapted bR/sub 560//sup DA/ forms of bacteriorhodopsin

Journal Article · Fri Jun 01 04:00:00 EDT 1979 · Biophys. J.; (United States)

DOI:https://doi.org/10.1016/S0006-3495(79)85269-8· OSTI ID:6189466

Terner, J; Hsieh, C L; El-Sayed, M A

The resonance Raman spectrum of the second intermediate in the bacteriorhodopsin cycle, bL/sub 550/, is obtained by a simple flow technique. The Schiff base linkage in this intermediate appears to be protonated, contrary to previous suggestion. The fingerprint region of the spectrum of bL/sub 550/ does not closely match those of any presently available model Schiff bases of retinal isomers, though some comparisons can be made. The resonance Raman spectrum of dark-adapted bacteriorhodopsin is obtained and decomposed by computer subtraction of the spectrum of bR/sub 570/. The remaining spectrum does not match the spectra of any model compounds presently in the literature. The spectra of bL/sub 550/ and dark-adapted bR/sub 560//sup DA/ from purple membrane in H/sub 2/O are compared to those in D/sub 2/O. It is found that changes in the spectrum occur in the 1,600--1,650 cm/sup -1/ region as well as in the 800--1,000 cm/sup -1/ region, but apparently not in the fingerprint region (1,100--1,400 cm/sup -1/). The possibilities of conformational changes of the retinal chromophore in the light adaptation process as well as the photosynthetic cycle are discussed.

• Research Organization: Univ. of California, Los Angeles
• OSTI ID: 6189466
• Journal Information: Biophys. J.; (United States), Journal Name: Biophys. J.; (United States) Vol. 26:3; ISSN BIOJA
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
BACTERIA
BODY
CHEMISTRY
DATA
DATA FORMS
ELECTROMAGNETIC RADIATION
EXPERIMENTAL DATA
EYES
GRAPHS
INFORMATION
MICROORGANISMS
NUMERICAL DATA
ORGANS
PHOTOCHEMISTRY
PIGMENTS
RADIATIONS
RAMAN SPECTRA
RESONANCE
RETINA
SENSE ORGANS
SPECTRA
VISIBLE RADIATION