TY - JOUR
T1 - Solar hydrogen-producing bionanodevice outperforms natural photosynthesis
AU - Lubner, Carolyn E.
AU - Applegate, Amanda M.
AU - Knörzer, Philipp
AU - Ganago, Alexander
AU - Bryant, Donald A.
AU - Happe, Thomas
AU - Golbeck, John H.
PY - 2011/12/27
Y1 - 2011/12/27
N2 - Although a number of solar biohydrogen systems employing photosystem I (PSI) have been developed, few attain the electron transfer throughput of oxygenic photosynthesis. We have optimized a biological/organic nanoconstruct that directly tethers F B, the terminal [4Fe-4S] cluster of PSI from Synechococcus sp. PCC 7002, to the distal [4Fe-4S] cluster of the [FeFe]-hydrogenase (H 2ase) from Clostridium acetobutylicum. On illumination, the PSI-[FeFe]-H 2ase nanoconstruct evolves H 2 at a rate of 2,200 ± 460 μmol mg chlorophyll -1 h -1, which is equivalent to 105 ± 22 e -PSI -1 s -1. Cyanobacteria evolve O 2 at a rate of approximately 400 μmol mg chlorophyll -1 h -1, which is equivalent to 47 e -PSI -1 s -1, given a PSI to photosystem II ratio of 1.8. The greater than twofold electron throughput by this hybrid biological/organic nanoconstruct over in vivo oxygenic photosynthesis validates the concept of tethering proteins through their redox cofactors to overcome diffusion-based rate limitations on electron transfer.
AB - Although a number of solar biohydrogen systems employing photosystem I (PSI) have been developed, few attain the electron transfer throughput of oxygenic photosynthesis. We have optimized a biological/organic nanoconstruct that directly tethers F B, the terminal [4Fe-4S] cluster of PSI from Synechococcus sp. PCC 7002, to the distal [4Fe-4S] cluster of the [FeFe]-hydrogenase (H 2ase) from Clostridium acetobutylicum. On illumination, the PSI-[FeFe]-H 2ase nanoconstruct evolves H 2 at a rate of 2,200 ± 460 μmol mg chlorophyll -1 h -1, which is equivalent to 105 ± 22 e -PSI -1 s -1. Cyanobacteria evolve O 2 at a rate of approximately 400 μmol mg chlorophyll -1 h -1, which is equivalent to 47 e -PSI -1 s -1, given a PSI to photosystem II ratio of 1.8. The greater than twofold electron throughput by this hybrid biological/organic nanoconstruct over in vivo oxygenic photosynthesis validates the concept of tethering proteins through their redox cofactors to overcome diffusion-based rate limitations on electron transfer.
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U2 - 10.1073/pnas.1114660108
DO - 10.1073/pnas.1114660108
M3 - Article
C2 - 22160679
AN - SCOPUS:84855497373
SN - 0027-8424
VL - 108
SP - 20988
EP - 20991
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 52
ER -