Primary photochemistry and photoisomerization of retinal at 77°K in cattle and squid rhodopsins

T. Suzuki, Robert Callender

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

The relative quantum yields of the photoreactions Rhodopsin⇆Bathorhodopsin⇆Isorhodopsin over an extended wavelength region have been determined in cattle and squid rhodopsins at 77°K. The quantum yields were found to be wavelength independent and unchanged for samples suspended in DO. The rhodopsin-bathorhodopsin forward and backward quantum yields sum to larger than one. These results are consistent with the previous suggestion that the excited singlet potential of rhodopsin has a single minimum along the 11-12 torsional coordinate. The values of the quantum yields are important for evaluating dynamic models of the rhodopsin-bathorhodopsin transition. We conclude that equilibration in the common excited state after excitation of rhodopsin, as previously suggested, does not occur. Models involving molecular excitation trajectories conserving torsional momenta and excited state to ground state surface crossings better fit the data, and a semiquantitative analysis is presented. Probabilities of surface crossings are calculated.

Original languageEnglish (US)
Pages (from-to)261-270
Number of pages10
JournalBiophysical Journal
Volume34
Issue number2
StatePublished - 1981
Externally publishedYes

Fingerprint

Photochemistry
Decapodiformes
Rhodopsin
Molecular Models

ASJC Scopus subject areas

  • Biophysics

Cite this

Primary photochemistry and photoisomerization of retinal at 77°K in cattle and squid rhodopsins. / Suzuki, T.; Callender, Robert.

In: Biophysical Journal, Vol. 34, No. 2, 1981, p. 261-270.

Research output: Contribution to journalArticle

@article{9fb77d8265c6404da162d19d14ae9cbf,
title = "Primary photochemistry and photoisomerization of retinal at 77°K in cattle and squid rhodopsins",
abstract = "The relative quantum yields of the photoreactions Rhodopsin⇆Bathorhodopsin⇆Isorhodopsin over an extended wavelength region have been determined in cattle and squid rhodopsins at 77°K. The quantum yields were found to be wavelength independent and unchanged for samples suspended in DO. The rhodopsin-bathorhodopsin forward and backward quantum yields sum to larger than one. These results are consistent with the previous suggestion that the excited singlet potential of rhodopsin has a single minimum along the 11-12 torsional coordinate. The values of the quantum yields are important for evaluating dynamic models of the rhodopsin-bathorhodopsin transition. We conclude that equilibration in the common excited state after excitation of rhodopsin, as previously suggested, does not occur. Models involving molecular excitation trajectories conserving torsional momenta and excited state to ground state surface crossings better fit the data, and a semiquantitative analysis is presented. Probabilities of surface crossings are calculated.",
author = "T. Suzuki and Robert Callender",
year = "1981",
language = "English (US)",
volume = "34",
pages = "261--270",
journal = "Biophysical Journal",
issn = "0006-3495",
publisher = "Biophysical Society",
number = "2",

}

TY - JOUR

T1 - Primary photochemistry and photoisomerization of retinal at 77°K in cattle and squid rhodopsins

AU - Suzuki, T.

AU - Callender, Robert

PY - 1981

Y1 - 1981

N2 - The relative quantum yields of the photoreactions Rhodopsin⇆Bathorhodopsin⇆Isorhodopsin over an extended wavelength region have been determined in cattle and squid rhodopsins at 77°K. The quantum yields were found to be wavelength independent and unchanged for samples suspended in DO. The rhodopsin-bathorhodopsin forward and backward quantum yields sum to larger than one. These results are consistent with the previous suggestion that the excited singlet potential of rhodopsin has a single minimum along the 11-12 torsional coordinate. The values of the quantum yields are important for evaluating dynamic models of the rhodopsin-bathorhodopsin transition. We conclude that equilibration in the common excited state after excitation of rhodopsin, as previously suggested, does not occur. Models involving molecular excitation trajectories conserving torsional momenta and excited state to ground state surface crossings better fit the data, and a semiquantitative analysis is presented. Probabilities of surface crossings are calculated.

AB - The relative quantum yields of the photoreactions Rhodopsin⇆Bathorhodopsin⇆Isorhodopsin over an extended wavelength region have been determined in cattle and squid rhodopsins at 77°K. The quantum yields were found to be wavelength independent and unchanged for samples suspended in DO. The rhodopsin-bathorhodopsin forward and backward quantum yields sum to larger than one. These results are consistent with the previous suggestion that the excited singlet potential of rhodopsin has a single minimum along the 11-12 torsional coordinate. The values of the quantum yields are important for evaluating dynamic models of the rhodopsin-bathorhodopsin transition. We conclude that equilibration in the common excited state after excitation of rhodopsin, as previously suggested, does not occur. Models involving molecular excitation trajectories conserving torsional momenta and excited state to ground state surface crossings better fit the data, and a semiquantitative analysis is presented. Probabilities of surface crossings are calculated.

UR - http://www.scopus.com/inward/record.url?scp=0019497625&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0019497625&partnerID=8YFLogxK

M3 - Article

C2 - 7236851

AN - SCOPUS:0019497625

VL - 34

SP - 261

EP - 270

JO - Biophysical Journal

JF - Biophysical Journal

SN - 0006-3495

IS - 2

ER -