Work

A computational study of possible mechanisms of singlet oxygen generation in miniSOG photoactive protein

Year: 2024

Type: article

Abstract: We report high-level electronic structure calculations of electronic states in the miniSOG (for mini Singlet Oxygen Generator) photoactive protein designed to produce singlet oxygen upon light exposure. We consider a model system with a riboflavin (RF) chromophore. To better understand the photosensitization process, we compute relevant electronic states of the combined oxygen-chromophore system and their couplings. The calculations suggest that singlet oxygen can be produced both by inter-system crossing, via a triplet state of the RF(T1)×O2(3Σ− g ) character as well as by triplet excitation energy transfer via a singlet state of the same character. Importantly, the former channel produces O2(1Σ+ g ), an excited state of singlet oxygen, which is known to convert with unit efficiency into O2(1∆g) The calculations also provide evidence for the production of the triplet state of the chromophore via internal conversion facilitated by oxygen. Our results provide concrete support to previously hypothesized scenarios.

Source: Molecular Physics

DOI: 10.1080/00268976.2024.2396548

Authors: Goran Giudetti, Anastasia R. Blinova, Bella L. Grigorenko, Anna I. Krylov

Institutions: University of Southern California, Lomonosov Moscow State University

Language: English

Topic: Photochemistry and Electron Transfer Studies

Subfield: Physical and Theoretical Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: green

Funders: National Science Foundation, Russian Science Foundation

Awards: G3107026921, G3862216691, New Coupled-cluster Methods for Linear and Non-linear Valence and Core-level Spectroscopy in Gas and Condensed Phase