EurekaMag.com logo
+ Site Statistics
References:
53,869,633
Abstracts:
29,686,251
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on LinkedInFollow on LinkedIn

+ Translate

Irreversible photobleaching of bacteriorhodopsin in a high-temperature intermediate state



Irreversible photobleaching of bacteriorhodopsin in a high-temperature intermediate state



Journal of Biochemistry 131(6): 785-790



The photo-intermediate state of bacteriorhodopsin is a metastable state that spontaneously transforms to the ground state over the energy barrier of a local minimum. As the recovery of the photocycle to the ground state and irreversible photobleaching to the denatured state may occur from the same local energy minimum, depending on the temperature, the structural stability of bacteriorhodopsin under illumination at high temperature was measured in order to study the intra- and inter-molecular interactions that contribute to the recovery of the ground state. Visible CD spectra of bacteriorhodopsin began to change at 60 degrees C from a bilobed to positive type in accordance with an appearance of an absorption peak at 470 nm. Irreversible photobleaching, the light-induced denaturation, also started to occur at 60 degrees C, suggesting some correlation between irreversible photobleaching and the structural change to the high-temperature intermediate state. However, bacteriorhodopsin in the dark was stable up to 70 degrees C, suggesting that there is some additional factor that lends structural stability to bacteriorhodopsin in the dark. The contribution of protein-protein interactions to stability is discussed on the basis of the difference in the denaturation behaviors between light and dark conditions.

(PDF emailed within 0-6 h: $19.90)

Accession: 010885751

Download citation: RISBibTeXText

PMID: 12038973

DOI: 10.1093/oxfordjournals.jbchem.a003166



Related references

Inhomogeneous stability of bacteriorhodopsin in purple membrane against photobleaching at high temperature. Proteins 54(3): 442-454, 2004

Structural change of bacteriorhodopsin in the purple membrane above pH 10 decreases heterogeneity of the irreversible photobleaching components. Journal of Biochemistry 142(3): 325-333, 2007

Structural changes in bacteriorhodopsin in purple membranes induced by irreversible photobleaching with heterogeneous and homogeneous stability. Photochemistry and Photobiology 86(2): 297-301, 2010

Two processes lead to a stable all-trans and 13-cis isomer equilibrium in dark-adapted bacteriorhodopsin; effect of high pressure on bacteriorhodopsin, bacteriorhodopsin mutant D96N and fluoro-bacteriorhodopsin analogues. European Biophysics Journal 31(7): 539-548, 2002

Photoconversion of the N intermediate of bacteriorhodopsin at low temperature. Biophysical Journal 64(2 PART 2): A212, 1993

Temperature and pH sensitivity of the O(640) intermediate of the bacteriorhodopsin photocycle. Biophysical Journal 61(4): 1001-1006, 1992

Deformation of helix C in the low temperature L-intermediate of bacteriorhodopsin. Journal of Biological Chemistry 279(3): 2147-2158, 2003

The nature of the multicomponent M-intermediate formation in the bacteriorhodopsin photocycle. II. Three components of the M-intermediate formation in the D96N bacteriorhodopsin mutant. Biokhimiya 59(3): 395-401, 1994

Solid state 13C and 15N NMR investigations of the N intermediate of bacteriorhodopsin. Biochemistry 33(30): 8853-8857, 1994

Solid state NMR study of the L-intermediate in bacteriorhodopsin. Biophysical Journal 70(2 PART 2): A107, 1996

Chromophore motion during the bacteriorhodopsin photocycle: polarized absorption spectroscopy of bacteriorhodopsin and its M-state in bacteriorhodopsin crystals. Embo Journal 10(9): 2353-2361, 1991

Conformers and multiple primary photoproducts of bacteriorhodopsin and N intermediate at low temperature. Rigaud, J -L, INSERM Colloquium; Structures and functions of retinal proteins, Colloque INSERM; Structures et fonctions des retino-proteines: 119-122, 1992

Structure of an early intermediate in the M-state phase of the bacteriorhodopsin photocycle. Biophysical Journal 81(6): 3442-3455, 2001

Kinetics of the N intermediate and the two pathways of recovery of the ground-state of bacteriorhodopsin. Febs (federation Of European Biochemical Societies) Letters. 311(3): 267-270, 1992