A 19F NMR Study of Rhodopsin Analogs: Use of Vinylfluororetinal Chromophores
摘要:
F-19 NMR spectra of 11-cis and 9-cis isomers of six fluorinated rhodopsin analogs with the label(s) located at the vinylic positions of the polyene chain (8-F, 10-F, 12-F, 14-F, 8,12-F-2, 10,14-F-2) are reported along with their UV-vis and CD spectra. The regiospecific F chemical shift data are analyzed in terms of chromophore changes and local perturbation resulting from specific interactions with protein. Two analogs (11-cis-12-F and 11-cis-8-F) and also 9,11-di-cis-12-F possess FOS (fluorine opsin shift) values uniquely different from others. Ab initio F NMR chemical shielding calculations of model structures provide support that a strong protein perturbation to the 12-F position prevails in the binding cavity and that F-8 shift is sensitive to variation of the nearby dihedral angle(s). Possible causes for the broad line width of the F signals of these membrane proteins are discussed.
Synthesis and properties of 12-fluororetinal and 12-fluororhodopsin. Model system for fluorine-19 NMR studies of visual pigments
作者:Robert S. H. Liu、Hiroyuki Matsumoto、Alfred E. Asato、Marlene Denny、Yoshinori Shichida、Toru Yoshizawa、F. W. Dahlquist
DOI:10.1021/ja00414a026
日期:1981.12
Preparation of (all-E)- and (11Z)-12-Haloretinals and (11Z,13Z)- and (13Z)-14-Haloretinals by the C15 + C5 Route ? Exploring the Possibility of Preparing any Retinoid Rationally Chemically Modified at any Position in the Conjugated Tail
作者:Yajie Wang、Johan Lugtenburg
DOI:10.1002/ejoc.200400488
日期:2004.12
that many more retinals chemically modified at the 12-position could be prepared in this manner. Selectfluor®, a good reagent for introducing a fluorine atom by electrophilic substitution, does not give the 12-fluororetinal system. However, 14-fluororetinal is simply available by reaction of the anion with Selectfluor®. Cl, Br and I atoms were also introduced at the 14-position of retinal both in the
A <sup>19</sup>F NMR Study of Rhodopsin Analogs: Use of Vinylfluororetinal Chromophores
作者:Leticia U. Colmenares、Walter P. Niemczura、Alfred E. Asato、Robert S. H. Liu
DOI:10.1021/jp952850k
日期:1996.1.1
F-19 NMR spectra of 11-cis and 9-cis isomers of six fluorinated rhodopsin analogs with the label(s) located at the vinylic positions of the polyene chain (8-F, 10-F, 12-F, 14-F, 8,12-F-2, 10,14-F-2) are reported along with their UV-vis and CD spectra. The regiospecific F chemical shift data are analyzed in terms of chromophore changes and local perturbation resulting from specific interactions with protein. Two analogs (11-cis-12-F and 11-cis-8-F) and also 9,11-di-cis-12-F possess FOS (fluorine opsin shift) values uniquely different from others. Ab initio F NMR chemical shielding calculations of model structures provide support that a strong protein perturbation to the 12-F position prevails in the binding cavity and that F-8 shift is sensitive to variation of the nearby dihedral angle(s). Possible causes for the broad line width of the F signals of these membrane proteins are discussed.