Pyridoxal photoenzymes for asymmetric radical-radical cross-couplings.

Pyridoxal 5'-phosphate (PLP) acts as a photoenzymatic cofactor enabling asymmetric radical-radical cross-couplings, expanding enzymatic bond formation capabilities.

• Why it matters: Understanding and harnessing the photophysical properties of enzyme cofactors can unlock new reactivity and selectivity in biocatalysis, addressing limitations of small-molecule catalysts.
• What they did: Researchers used non-native benzylamine substrates and Fӧrster resonance energy transfer to excite the PLP quinonoid intermediate, facilitating radical-radical cross-couplings through a redox-neutral, photoexcited pathway.
• The result: This approach overcomes previous challenges in radical reactions within enzymes, opening new avenues for bond-forming reactions and broadening the scope of PLP-dependent enzymatic transformations.