Skip to main content
PMC home page
Biophysical Journal logoLink to Biophysical Journal
. 1992 Jun;61(6):1630–1637. doi: 10.1016/S0006-3495(92)81966-5

Nanosecond photolytic interruption of bacteriorhodopsin photocycle

K-590 → BR-570 reaction

V Bazhenov 1, P Schmidt 1, G H Atkinson 1
PMCID: PMC1260456  PMID: 19431837

Abstract

The molecular processes comprising the room temperature bacteriorhodopsin (BR) photocycle are examined through the properties of the photo-induced reverse reaction, K-590 + hν → BR-570 (K → BR). Two sequential pumping pulses, each of 10-ns duration, are used, respectively, to initiate the photocycle via the forward BR-570 + hν → K-590 (BR → K) reaction (532 nm) and to photolytically interrupt the thermal BR photocycle after a 20-ns delay via K → BR (620-700 nm). The ground-state BR-570 population, monitored by 633-nm absorption 200 μs after the photocycle begins, provides a quantitative measure of the efficiency with which K → BR interrupts the photocycle to reform BR-570. The quantum yield (Φ) for K → BR is found to be 1.6 ± 0.1 times larger than that for BR → K which, when compared to a Φ of 0.64 for BR → K, suggests that Φ for K → BR is ≈ 1.0. The significance of such a high efficiency K → BR reaction with respect to mechanistic descriptions of the BR photocycle is discussed.

Full text

PDF
1630

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Applebury M. L., Peters K. S., Rentzepis P. M. Primary intermediates in the photochemical cycle of bacteriorhodopsin. Biophys J. 1978 Sep;23(3):375–382. doi: 10.1016/S0006-3495(78)85456-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Becher B., Ebrey T. G. The quantum efficiency for the photochemical conversion of the purple membrane protein. Biophys J. 1977 Feb;17(2):185–191. doi: 10.1016/S0006-3495(77)85636-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Becher B., Ebrey T. G. The quantum efficiency for the photochemical conversion of the purple membrane protein. Biophys J. 1977 Feb;17(2):185–191. doi: 10.1016/S0006-3495(77)85636-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Chernavskii D. S., Chizhov I. V., Lozier R. H., Murina T. M., Prokhorov A. M., Zubov B. V. Kinetic model of bacteriorhodopsin photocycle: pathway from M state to bR. Photochem Photobiol. 1989 May;49(5):649–653. doi: 10.1111/j.1751-1097.1989.tb08437.x. [DOI] [PubMed] [Google Scholar]
  5. Goldschmidt C. R., Kalisky O., Rosenfeld T., Ottolenghi M. The quantum efficiency of the bacteriorhodopsin photocycle. Biophys J. 1977 Feb;17(2):179–183. doi: 10.1016/S0006-3495(77)85635-X. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Goldschmidt C. R., Ottolenghi M., Korenstein R. On the primary quantum yields in the bacteriorhodopsin photocycle. Biophys J. 1976 Jul;16(7):839–843. doi: 10.1016/S0006-3495(76)85732-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Govindjee R., Balashov S. P., Ebrey T. G. Quantum efficiency of the photochemical cycle of bacteriorhodopsin. Biophys J. 1990 Sep;58(3):597–608. doi: 10.1016/S0006-3495(90)82403-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Grieger I., Atkinson G. H. Photolytic interruptions of the bacteriorhodopsin photocycle examined by time-resolved resonance raman spectroscopy. Biochemistry. 1985 Sep 24;24(20):5660–5665. doi: 10.1021/bi00341a056. [DOI] [PubMed] [Google Scholar]
  9. Hampp N., Bräuchle C., Oesterhelt D. Bacteriorhodopsin wildtype and variant aspartate-96 --> aspargine as reversible holographic media. Biophys J. 1990 Jul;58(1):83–93. doi: 10.1016/S0006-3495(90)82355-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Hanamoto J. H., Dupuis P., El-Sayed M. A. On the protein (tyrosine)-chromophore (protonated Schiff base) coupling in bacteriorhodopsin. Proc Natl Acad Sci U S A. 1984 Nov;81(22):7083–7087. doi: 10.1073/pnas.81.22.7083. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Ippen E. P., Shank C. V., Lewis A., Marcus M. A. Subpicosecond spectroscopy of bacteriorhodopsin. Science. 1978 Jun 16;200(4347):1279–1281. doi: 10.1126/science.663607. [DOI] [PubMed] [Google Scholar]
  12. Kaufmann K. J., Rentzepis P. M., Stoeckenius W., Lewis A. Primary photochemical processes in bacteriorhodopsin. Biochem Biophys Res Commun. 1976 Feb 23;68(4):1109–1115. doi: 10.1016/0006-291x(76)90310-7. [DOI] [PubMed] [Google Scholar]
  13. Lozier R. H., Bogomolni R. A., Stoeckenius W. Bacteriorhodopsin: a light-driven proton pump in Halobacterium Halobium. Biophys J. 1975 Sep;15(9):955–962. doi: 10.1016/S0006-3495(75)85875-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Milder S. J., Kliger D. S. A time-resolved spectral study of the K and KL intermediates of bacteriorhodopsin. Biophys J. 1988 Mar;53(3):465–468. doi: 10.1016/S0006-3495(88)83124-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Oesterhelt D., Stoeckenius W. Isolation of the cell membrane of Halobacterium halobium and its fractionation into red and purple membrane. Methods Enzymol. 1974;31:667–678. doi: 10.1016/0076-6879(74)31072-5. [DOI] [PubMed] [Google Scholar]
  16. Oesterhelt D., Stoeckenius W. Rhodopsin-like protein from the purple membrane of Halobacterium halobium. Nat New Biol. 1971 Sep 29;233(39):149–152. doi: 10.1038/newbio233149a0. [DOI] [PubMed] [Google Scholar]
  17. Ottolenghi M., Sheves M. Synthetic retinals as probes for the binding site and photoreactions in rhodopsins. J Membr Biol. 1989 Dec;112(3):193–212. doi: 10.1007/BF01870951. [DOI] [PubMed] [Google Scholar]
  18. Sakmar T. P., Franke R. R., Khorana H. G. Glutamic acid-113 serves as the retinylidene Schiff base counterion in bovine rhodopsin. Proc Natl Acad Sci U S A. 1989 Nov;86(21):8309–8313. doi: 10.1073/pnas.86.21.8309. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Sasaki N., Tokunaga F., Yoshizawa T. Two forms of intermediates of frog rhodopsin in rod outer segments. Biochim Biophys Acta. 1983 Jan 13;722(1):80–87. doi: 10.1016/0005-2728(83)90159-7. [DOI] [PubMed] [Google Scholar]
  20. Stoeckenius W., Lozier R. H. Light energy conversion in Halobacterium halobium. J Supramol Struct. 1974;2(5-6):769–774. doi: 10.1002/jss.400020519. [DOI] [PubMed] [Google Scholar]

Articles from Biophysical Journal are provided here courtesy of The Biophysical Society

RESOURCES