Infrared Studies of Rhodopsin, and Its Low Temperature Photoproducts, Bathorhodopsin and Isorhodopsin (Ftir, Vision)

Fourier-transform infrared difference spectroscopy has been used to detect the vibrational modes of the chromophore and protein that change in position and intensity between rhodopsin and the photoproducts formed at low temperature (70K), bathorhodopsin and isorhodopsin. A method has been developed to obtain infrared difference spectra between rhodopsin and bathorhodopsin, bathorhodopsin and isorhodopsin, and rhodopsin and isorhodopsin. To aid in identification of the vibrational modes, experiments were performed on deuterated and hydrated films of native rod outer segments and rod outer segments regenerated with either retinal containing ('13)C at carbon-15 or 15-deuterioretinal, or hydrated films of rod outer segments regenerated with retinal containing ('13)C at either carbon-10, carbon-11, carbon-13, or carbons-14 and -15. These infrared studies provide independent verification of the resonance Raman result that the retinal in bathorhodopsin is all-trans-like. The positions of the C=N stretch in the deuterated pigment and the deuterated pigments regenerated with 1-cis 15-deuterioretinal or 11-cis containing ('13)C at carbon-15 are indicative that the Schiff base linkage is protonated in rhodopsin, bathorhodopsin, and isorhodopsin. Furthermore, the C=N stretching frequency occurs at the same position in all three species. The data indicate that the protonated Schiff base has a C=N trans conformation in all three species, and that the C10-C11 single bond is s-trans in bathorhodopsin. Finally, evidence is presented that, even in these early stages of the rhodopsin bleaching sequence, changes are occurring in the opsin.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Bagley, Kimberly Ann

• Biophysics, General

Language dc:language

eng

Identifier

(UMI)AAI8711770

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/77400