ABSTRACT THE chromophore of visual pigments is generally assumed to be a protonated Schiff base of the 11-_cis_ retinylidene (rhodopsins) or the 11-_cis_ 3-dehydroretinylidene

(porphyropsins) groups linked through a lysine amino group to a specific glycoli-poprotein moiety (opsin)1. This protonated Schiff base hypothesis has been supported by plausible though not

unequivocal chemical evidence2,3. Recent studies using the physical technique of resonance Raman spectroscopy have also seemed to support this view4–7. In an attempt to confirm this

assignment and to explore further the structure and microenvironment of the chomophore, we have studied the nuclear magnetic resonance (NMR) spectra of aqueous suspensions of bovine

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NewYork, 1957). Book  Google Scholar  Download references AUTHOR INFORMATION Author notes * ROGER FAGER Present address: Department of Physiology, School of Medicine, University of Virginia,

Charlottesville, Virginia * DENNIS TORCHIA Present address: National Institutes of Health, Bethesda, Maryland AUTHORS AND AFFILIATIONS * Guelph-Waterloo Centre for Graduate Work in

Chemistry, Guelph, Ontario JOHN SHRIVER, GEORGE MATEESCU, ROGER FAGER & DENNIS TORCHIA * Case Western Reserve University, Cleveland, Ohio E. W. ABRAHAMSON Authors * JOHN SHRIVER View

author publications You can also search for this author inPubMed Google Scholar * GEORGE MATEESCU View author publications You can also search for this author inPubMed Google Scholar * ROGER

FAGER View author publications You can also search for this author inPubMed Google Scholar * DENNIS TORCHIA View author publications You can also search for this author inPubMed Google

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ARTICLE SHRIVER, J., MATEESCU, G., FAGER, R. _et al._ Unprotonated chromophore-protein bond in visual pigments from 13C-NMR spectra. _Nature_ 270, 271–274 (1977).

https://doi.org/10.1038/270271a0 Download citation * Received: 20 June 1977 * Accepted: 16 September 1977 * Issue Date: 17 November 1977 * DOI: https://doi.org/10.1038/270271a0 SHARE THIS

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