Molecular design principles for Photosystem I-based biohybrid solar fuel catalysts.
Emerson, M.D., Damaraju, S.N.S., Short, A.H., Alvord, Z.B., Palmer, Z.A., Mehra, H.S., Brininger, C.M., Vermaas, J.V., Utschig, L.M., Gisriel, C.J.(2026) bioRxiv 
- PubMed: 41929101 Search on PubMedSearch on PubMed Central
- DOI: https://doi.org/10.64898/2026.03.23.713776
- Primary Citation Related Structures: 
10EG, 10KF - PubMed Abstract: 
Direct solar-to-chemical conversion offers a compelling route to clean, dispatchable energy. Photosystem I (PSI), an evolutionarily optimized light-driven oxidoreductase central to oxygenic photosynthesis, can be repurposed for direct solar-fuel production by efficiently coupling its photochemistry to catalysts, thereby storing sunlight as chemical energy in the H-H bond of H2. One promising architecture integrates PSI with Pt nanoparticle (PtNP) catalysts to create photocatalytic PSI-PtNP biohybrids. Advancing these systems requires molecular-level insight into protein-nanoparticle interactions and the bio-nano electron transfer pathways that govern activity; however, progress has been constrained by limited structural data to guide rational design. Here, we present two molecular structures of active PSI-PtNP assemblies that (a) compare thermophilic and mesophilic PSI scaffolds and (b) probe how removal of the terminal [4Fe-4S] clusters and stromal subunits in PSI reshapes protein-nanoparticle interfaces and photocatalysis. Structural analyses and molecular dynamics simulations define the interface topology, electrostatics, and cofactor-to-nanoparticle distances, revealing key molecular features that control biohybrid formation and electron transfer efficiency. These data establish mechanistic links between scaffold composition, bio-nano interface geometry, and catalytic performance, yielding design principles for optimizing PSI-PtNP architectures. The resulting structure-function insights provide a blueprint for engineering PSI-based solar-fuels systems and, more broadly, inform the design of protein-nanomaterial interfaces for light-driven catalysis.
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA.
Organizational Affiliation: 






















