102574-15-2Relevant academic research and scientific papers
Constraints of opsin structure on the ligand-binding site: Studies with ring-fused retinals
Hirano, Takahiro,Lim, In Taek,Kim, Don Moon,Zheng, Xiang-Guo,Yoshihara, Kazuo,Oyama, Yoshiaki,Imai, Hiroo,Shichida, Yoshinori,Ishiguro, Masaji
, p. 606 - 615 (2007/10/03)
Ring-fused retinal analogs were designed to examine the hulatwist mode of the photoisomerization of the 9-cis retinylidene chromophore. Two 9-cis retinal analogs, the C11-C13 five-membered ring-fused and the C12-C14 five-membered ring-fused retinal derivatives, formed the pigments with opsin. The C11-C13 ring-fused analog was isomerized to a relaxed all-trans chromophore (λmax > 400 nm) at even - 269°C and the Schiff base was kept protonated at 0°C. The C12-C14 ring-fused analog was converted photochemically to a bathorhodopsin-like chromophore (λmax = 583 nm) at -196°C, which was further converted to the deprotonated Schiff base at 0°C. The model-building study suggested that the analogs do not form pigments in the retinal-binding site of rhodopsin but form pigments with opsin structures, which have larger binding space generated by the movement of transmembrane helices. The molecular dynamics simulation of the isomerization of the analog chromophores provided a twisted C11-C12 double bond for the C12-C14 ring-fused analog and all relaxed double bonds with a highly twisted C10-C11 bond for the C11-C13 ring-fused analog. The structural model of the C11-C13 ring-fused analog chromophore showed a characteristic flip of the cyclohexenyl moiety toward transmembrane segments 3 and 4. The structural models suggested that hula twist is a primary process for the photoisomerization of the analog chromophores.
Role of Retinal Isomerizations and Rotations in the Photocycle of Bacteriorhodopsin
Albeck, Amnon,Friedman, Noga,Sheves, Mordechai,Ottolenghi, Michael
, p. 4614 - 4618 (2007/10/02)
Artificial bacteriorhodopsin (bR) pigments based on synthetic retinal analogues with selectively blocked single and double bonds were prepared.It was shown that rotations around single bonds C12-C13 and C10-C11 and isomerizations of C11=C12 and C9=C10 are
