Spectroscopic and Computational Observation of Glutamine Tautomerization in the Blue Light Sensing Using Flavin Domain Photoreaction

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2FCZ______%3A_____%2F23%3AN0000095" target="_blank" >RIV/CZ______:_____/23:N0000095 - isvavai.cz</a>

Alternative codes found

RIV/CZ______:_____/23:N0000092

Result on the web

<a href="https://pubs.acs.org/doi/10.1021/jacs.2c10621" target="_blank" >https://pubs.acs.org/doi/10.1021/jacs.2c10621</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/jacs.2c10621" target="_blank" >10.1021/jacs.2c10621</a>

Result language

angličtina

Original language name

Spectroscopic and Computational Observation of Glutamine Tautomerization in the Blue Light Sensing Using Flavin Domain Photoreaction

Original language description

Blue light sensing using flavin (BLUF) domains constitute a family of flavin-binding photoreceptors of bacteria and eukaryotic algae. BLUF photoactivation proceeds via a light-driven hydrogen-bond switch among flavin adenine dinucleotide (FAD) and glutamine and tyrosine side chains, whereby FAD undergoes electron and proton transfer with tyrosine and is subsequently re-oxidized by a hydrogen back-shuttle in picoseconds, constituting an important model system to understand proton-coupled electron transfer in biology. The specific structure of the hydrogen-bond patterns and the prevalence of glutamine tautomeric states in dark-adapted (DA) and light-activated (LA) states have remained controversial. Here, we present a combined femtosecond stimulated Raman spectroscopy (FSRS), computational chemistry, and site-selective isotope labeling Fourier-transform infrared spectroscopy (FTIR) study of the Slr1694 BLUF domain. FSRS showed distinct vibrational bands from the FADS1 singlet excited state. We observed small but significant shifts in the excited-state vibrational frequency patterns of the DA and LA states, indicating that these frequencies constitute a sensitive probe for the hydrogen-bond arrangement around FAD. Excited-state model calculations utilizing four different realizations of hydrogen bond patterns and glutamine tautomeric states were consistent with a BLUF reaction model that involved glutamine tautomerization to imidic acid, accompanied by a rotation of its side chain. A combined FTIR and double-isotope labeling study, with 13C labeling of FAD and 15N labeling of glutamine, identified the glutamine imidic acid C=N stretch vibration in the LA state and the Gln C=O in the DA state. Hence, our study provides support for glutamine tautomerization and side-chain rotation in the BLUF photoreaction.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10406 - Analytical chemistry

Project

<a href="/en/project/GM21-09692M" target="_blank" >GM21-09692M: Clarifying quantum limits in biomolecules by utilizing entangled photons generated from protein bound cofactor modeled on orange carotenoid protein</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2023

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of the American Chemical Society

ISSN

0002-7863

e-ISSN

1520-5126

Volume of the periodical

145

Issue of the periodical within the volume

2

Country of publishing house

US - UNITED STATES

Number of pages

13

Pages from-to

1040-1052

UT code for WoS article

000922860800001

EID of the result in the Scopus database

2-s2.0-85146042187