51804-54-7Relevant articles and documents
Backbone modification of retinal induces protein-like excited state dynamics in solution
Sovdat, Tina,Bassolino, Giovanni,Liebel, Matz,Schnedermann, Christoph,Fletcher, Stephen P.,Kukura, Philipp
supporting information; experimental part, p. 8318 - 8320 (2012/06/30)
The drastically different reactivity of the retinal chromophore in solution compared to the protein environment is poorly understood. Here, we show that the addition of a methyl group to the C=C backbone of all-trans retinal protonated Schiff base acceler
6-s-cis conformation and polar binding pocket of the retinal chromophore in the photoactivated state of rhodopsin
Ahuja, Shivani,Eilers, Markus,Hirshfeld, Amiram,Yan, Elsa C. Y.,Ziliox, Martine,Sakmar, Thomas P.,Sheves, Mordechai,Smith, Steven O.
experimental part, p. 15160 - 15169 (2010/01/29)
The visual pigment rhodopsin is unique among the G protein-coupled receptors in having an 11-cis retinal chromophore covalently bound to the protein through a protonated Schiff base linkage. The chromophore locks the visual receptor in an inactive conformation through specific steric and electrostatic interactions. This efficient inverse agonist is rapidly converted to an agonist, the unprotonated Schiff base of all-trans retinal, upon light activation. Here, we use magic angle spinning NMR spectroscopy to obtain the 13C chemical shifts (C5-C20) of the all-trans retinylidene chromophore and the 15N chemical shift of the Schiff base nitrogen in the active metarhodopsin II intermediate. The retinal chemical shifts are sensitive to the conformation of the chromophore and its molecular interactions within the protein-binding site. Comparison of the retinal chemical shifts in metarhodopsin II with those of retinal model compounds reveals that the Schiff base environment is polar. In particular, the 13C15 and 15Nε chemical shifts indicate that the CdN bond is highly polarized in a manner that would facilitate Schiff base hydrolysis. We show that a strong perturbation of the retinal 13C12 chemical shift observed in rhodopsin is reduced in wild-type metarhodopsin II and in the E181Q mutant of rhodopsin. On the basis of the T1 relaxation time of the retinal 13C18 methyl group and the conjugated retinal 13C5 and 13C8 chemical shifts, we have determined that the conformation of the retinal C6-C7 single bond connecting the β-ionone ring and the retinylidene chain is 6-s-cis in both the inactive and the active states of rhodopsin. These results are discussed within the general framework of ligand-activated G protein-coupled receptors.
Cyclodextrin retinylidene: A biomimetic kinetic trap model for rhodopsin
Kpegba, Kafui,Murtha, Matthew,Nesnas, Nasri
, p. 1523 - 1526 (2007/10/03)
All trans retinal was attached to both the primary face and the secondary face of β-cyclodextrin via a Schiff base linkage, analogous to that in rhodopsin. The new models were evaluated and compared with n-butylamine retinylidene Schiff base for their rates of hydrolysis, and factors that influence such rates. Competition studies using adamantane carboxylate demonstrated the kinetic trap theory by diminishing the binding of retinal in the cyclodextrin, thereby augmenting the rate of hydrolysis. NMR experiments indicate that the retinylidene is most probably bound in the form of a dimer.
Constitution and stabilisation of retinal schiff bases in phosphatidylcholine liposomes
Singh, Anil K.,Das, Joydip
, p. 187 - 194 (2007/10/03)
All-trans-retinal (1) intercalated in lecithin liposomes reacts with n-butylamine yielding the all-trans-N-retinylidene-n-butylamine (2). The rate of formation of 2 in liposomes is approximately 5-6 times slower as compared to the rate in aqueous buffer (
A 19F NMR study of rhodopsin analogs: use of vinylfluororetinal chromophores
Colmenares, Leticia U.,Niemczura, Walter P.,Asato, Alfred E.,Liu, Robert S. H.
, p. 9175 - 9180 (2007/10/03)
19F 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-F2, 10,14-F2) are reported along with their UV-vis and CD spec
Liposome stabilised retinal Schiff bases
Das, Joydip,Singh, Anil K.
, p. 615 - 617 (2007/10/02)
All-trans-N-retinylidene-n-butylamine (3) can be stabilised in liposomes of phosphatidylcholine.The rate of romation of the Schiff base is found to decrease with increasing chloesterol concentration in the membrane.
Retinylidene Schiff Bases in Phosphatidylcholine Reverse Micelles: Formation, Protonation and Stability
Kapil, Mrunalini M.,Singh, Anil K.
, p. 1785 - 1790 (2007/10/02)
All-trans-N-retinylidene-n-butylamine 3 has been formed in inverted micelles of phosphatidylcholine (PC)-hexane containing varying amounts of water (/ = 0-3) and the formation, protonation and stability have been studied.The micelles have been fo
PHENOL-RETINAL SCHIFF BASE HYDROGEN BONDS - INFLUENCE OF STERIC HINDRANCE AND PHENOL ACIDITY ON THE THERMODYNAMIC DATA OF FORMATION AND PROTON TRANSFER
Brzezinski, Bogumil,Olejnik, Jerzy,Zundel, G.
, p. 89 - 99 (2007/10/02)
CD2Cl2 solutions of four trans-retinal Schiff bases (containing methylamine, n-butylamine, t-butylamine and 5-butyl-nonylamine), their perchlorates and their 1:1 complexes with 3,4-disubstituted and 4-monosubstituted phenols were studied as a function of
Retinylidene Schiff bases in surfactant-solubilized water pools in heptane
Singh, Anil K.,Sandorfy, Camille,Fendler, Janos H.
, p. 1514 - 1522 (2007/10/02)
All-trans-retinal (1) was reacted with n-butylamine in sodium bis(2-ethylhexyl)sulfosuccinate (AOT) reverse micelles in heptane to form all-trans-N-retinylidene-n-butylamine Schiff bases (2).The extent of protonation of 2 by 3-chloropropionic acid (CPA) to give 3 in AOT reverse micelles in heptane was found to depend on the ratio of (CPA) to (2), as well as on / (i.e., on the ω value).At any given (2) and ω values, increasing amounts of CPA increased the protonation and at any given constant (2) and (CPA), increasing ω values also increased the protonation.Over a period of 24 hours, there was only 4percent decomposition of 2 in AOT reverse micelles in heptane at ω= 24.Conversely, in three hours, 23percent of 3 decomposed in the same system.The trans to cis photoisomerization of 2 in heptane occurred at a much faster rate in the presence of AOT reverse micelles than in their absence.The appearance of carboxylate peaks (FTIR, 1400-1500 cm-1) indicated that the larger the AOT solubilized water pools, the greater the CPA dissociation. 1 also reacted with the α-NH2 group of l-lysine (4) in AOT reverse micelles in heptane to give the corresponding Schiff base 6.Protonation of 6 occurred either intramolecularly or by reaction with unreacted 4.These results were discussed in terms of rhodopsin protonations.Key words: retinylidene Schiff bases, reverse micelles, protonation of Schiff bases, trans to cis photodimersization.
On the Thermal Behavior of Schiff Bases of Retinal and Its Analogues: 1,2-Dihydropyridine Formation via Six-?-Electron Electrocyclization of 13-Cis Isomers
Lera, Angel R. de,Reischl, Wolfgang,Okamura, William H.
, p. 4051 - 4063 (2007/10/02)
Reaction of 13-tert-butyl-13-cis-retinal (3a) with n-butylamine affords n-butyl Schiff base 3b, which affords the electrocyclized dihydropyridine (DHP) 7b with a half-life of ca. 11 min at 23 deg C in benzene-d6.The corresponding 11,13-dicis Sc
