The primary event in vision investigated by time-resolved fluorescence spectroscopy

A. G. Doukas, M. R. Junnarkar, R. R. Alfano, R. H. Callender, V. Balogh-Nair

Research output: Contribution to journalArticle

11 Scopus citations


The picosecond fluorescence kinetics and quantum yield from bovine rhodopsin were measured in the 5–40 degrees K range. The fluorescence rise and decay times are faster than our resolution of 15 ps (full width at half maximum) over this entire temperature range. The size of the observed emission was also temperature independent, and we find that the upper limit of rhodopsin's fluorescence quantum yield to be phi f approximately equal to 10(-5). Replacing all of rhodopsin's exchangeable protons with deuterons by suspending rhodopsin in D2O had no effect on either the kinetics of the emission or the value of the quantum yield. Our data provide strong confirmation of the idea that the first step in the visual process is an excited-state cis-to-trans isomerization about the C11-C12 double bond of retinal.

Original languageEnglish (US)
Pages (from-to)795-798
Number of pages4
JournalBiophysical Journal
Issue number6
Publication statusPublished - Jan 1 1985
Externally publishedYes


ASJC Scopus subject areas

  • Biophysics

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