Enhancing Proton-Coupled Electron Transfer in Blue Light Using FAD Photoreceptor AppA_BLUF.

ABSTRACT: The Blue Light Using FAD (BLUF) photoreceptor utilizes a noncovalently bound FAD to absorb light and trigger the initial ultrafast events in receptor activation. FAD undergoes 1 and 2 electron reduction as an enzyme redox cofactor, and studies on the BLUF photoreceptor PixD revealed the formation of flavin radicals (FAD^•- and FADH^•) during the photocycle, supporting a general mechanism for BLUF operation that involves PCET from a conserved Tyr to the oxidized FAD. However, no radical intermediates are observed in the closely related BLUF proteins AppA_BLUF and BlsA, and replacing the conserved Tyr with fluoro-Tyr analogs that increase the acidity of the phenol OH has a minor effect on AppA_BLUF photoactivation in contrast to PixD where the photocyc

SUBMITTER: He Y 

PROVIDER: S-EPMC11726546 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature