Post on 20-Jul-2020
• Optimize biotinylation reaction conditions• Functionalize PSII with biotin on the stromal-side• Co-assemble the biotinylated PSI and PSII onto streptavidin-
coated gold particles
• Perform oxygen and hydrogen evolution assays for PSI/PSII-AuNP conjugates
Conclusions
Oriented Interface of PSI and PSII for Solar Driven Hydrogen EvolutionAlexandra Quiñones-Meléndez1, Evan A. Gizzie2, Chris Stachurski2, G. Kane Jennings3 and David E. Cliffel2
1Department of Chemical Engineering, University of Puerto Rico at Mayaguez, PR 006802Department of Chemistry, Vanderbilt University, Nashville, TN 37235
3Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN 37235
Photosystem I (PSI) and Photosystem II (PSII) carry out photosynthesis in green plants. PSI has hydrogen reduction abilities, and PSII has water splitting power.
Hydrogen is a strong contender as a next generation clean and green fuel. What if photosynthesis became our hydrogen source?
Results
Thanks to the Cliffel Research Group especially to Evan A. Gizzie, Chris Stachurski, and Dilek Dervishogullari for their
collaboration.
Hydrogen Evolution Role of Photosystems I and II
Objectives
PSI Extraction
Interface PSI and PSII together in a head-to-tail fashion tosustainably generate H2 and O2 from sunlight and water:
• Functionalize PSI with biotin on the luminal-side
• Functionalize PSII with biotin on the stromal-side
• Co-assemble on gold nanoparticle
PSI is extracted from spinach
Methodology
Stromal-side Passivation of PSI
N N
N𝑁𝐻2 𝑁𝐻2
𝑁𝐻2
Sulfo-NHS-Acetate
Native Photosystem I Acetylated Photosystem I
HO
Acetylated Photosystem I
Biotin
Biotinylated Photosystem I
N N
N
PSII PSI
PSI has been functionalizedon its luminal side, allowingfor oriented deposition onstreptavidin functionalizedgold nanoparticles.
0
300
600
900
480 520 560 600
Inte
nsi
ty (
a.u
.)
Wavelength (nm)
Native PSI
Acetylated PSI
Biotinylated PSI
Biotinylation of Photosystem I was determined spectrophotometrically usingFluorescein Isothiocyanate (FITC), which reacts with primary amines.
Luminal-side Biotinylation of PSI
N N
N
𝑁𝐻2 𝑁𝐻2 𝑁𝐻2
88
3622
0
40
80
NativePSI
AcetylatedPSI
BiotinylatedPSI
Lysi
ne
/PSI
Rat
io
SDS-PAGE Analysis Fluorescein Spectroscopy
Acknowledgements
Add Sulfo-NHS-Acetate
Introduction
We will integrate these two proteins into a single “wired” assembly for simultaneous water splitting and H2 generation.
PSI and PSII Assembly
Grinding buffer
Cheese cloth
Centrifuge
Discard
Re-suspended with buffer and discard supernatant (3x)
Re-suspended with buffer and 1% surfactant (3x)
Discard
CentrifugeCentrifuge
Dialysis
Stromal side
Luminal side
We gratefully acknowledge financial support from the National Science Foundation (Grant No: 1560414), in collaboration with
Vanderbilt Institute of Nanoscale Science and Engineering (VINSE)
References
Future Directions
[1] Ciesielski, P. N., Cliffel, D. E., & Jennings, G. K. (2011). Kinetic model of the photocatalytic effect of a photosystem I monolayer on a planar electrode surface. Journal of Physical Chemistry A, 115(15), 3326–3334.
[2] Utschig, L. M., Silver, S. C., Mulfort, K. L., & Tiede, D. M. (2011). Nature-Driven Photochemistry for Catalytic Solar Hydrogen, 16334–16337.
[3] LeBlanc, G., Gizzie, E., Yang, S., Cliffel, D. E., & Jennings, G. K. (2014). Photosystem I protein films at electrode surfaces for solar energy conversion. Langmuir, 30(37), 10990–1001. http://doi.org/10.1021/la500129q
4
7
16
34
55
78
105
PsaA/PsaB
PsaD/PsaF/PsaL
Psa/PsaJ
PsaC
BiotinBiotin
Biotin
Biological Science, Copyright 2005, Pearson Benjamin Cummings
[3] LeBlanc, Langmuir, 30(37), 10990–1001.