title: Ultrafast Photoinduced Deactivation Dynamics of Proteorhodopsin.
abstract: We report femtosecond time-resolved absorption change measurements of the photoinduced deactivation dynamics of a microbial rhodopsin in the ultraviolet-visible and mid-infrared range. The blue light quenching process is recorded in green proteorhodopsin's (GPR) primary proton donor mutant E108Q from the deprotonated 13-cis photointermediate. The return of GPR to the dark state occurs in two steps, starting with the photoinduced 13-cis to all-trans reisomerization of the retinal. The subsequent Schiff base reprotonation via the primary proton acceptor (D97) occurs on a nanosecond time scale. This step is two orders of magnitude faster than that in bacteriorhodopsin, potentially because of the very high pKAof the GPR primary proton acceptor.
authors.affiliation: Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt am Main , Max-von-Laue-Str. 7, 60438 Frankfurt am Main, Germany.
authors.forename: C Elias
authors.initials: CE
authors.lastname: Eckert
authors.affiliation: Institute of Biophysical Chemistry, Goethe-University Frankfurt am Main , Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany.
authors.forename: Jagdeep
authors.initials: J
authors.lastname: Kaur
authors.affiliation: Institute of Biophysical Chemistry, Goethe-University Frankfurt am Main , Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany.
authors.forename: Clemens
authors.initials: C
authors.lastname: Glaubitz
authors.affiliation: Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt am Main , Max-von-Laue-Str. 7, 60438 Frankfurt am Main, Germany.
authors.forename: Josef
authors.identifier: http://orcid.org/0000-0002-8496-8240
authors.initials: J
authors.lastname: Wachtveitl
mesh_terms: D001436:Bacteriorhodopsins / Q000737:chemistry; D008027:Light; D011522:Protons; D012172:Retinaldehyde / Q000737:chemistry; D012243:Rhodopsin / Q000737:chemistry*; D025604:Rhodopsins, Microbial / Q000737:chemistry*; D012545:Schiff Bases / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D011522:Protons; D025604:Rhodopsins, Microbial; D012545:Schiff Bases; C413548:proteorhodopsin; D001436:Bacteriorhodopsins; D012243:Rhodopsin; D012172:Retinaldehyde