Biophysical Society Thematic Meeting - October 25-30, 2015

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Polymers and Self Assembly: From Biology to Nanomaterials Poster Session II
33-POS Board 33
Immobilization of RubisCO by Self-Assembled Nanotubes
Yuan Sun, Sriram Satagopan, F. Robert Tabita, Jon Parquette.
The Ohio State University, Columbus, USA.
Biology-inspired catalysts, such as ribulose-1,5-bisphosphate carboxylase-oxygenase
(RuBisCO), efficiently reduce CO2 resulting in products that are subsequently metabolized to
energy-rich compounds like glucose by the sequential action of multiple enzymes. However, the
use of free or cell-based enzymes as biocatalysts for large-scale industrial processes pose
significant limitations due to their incompatibility with reaction conditions that often depart from
their physiological states. Although biological catalysts, such as RubisCO, are among the most
efficient and ubiquitous catalysts for CO2 fixation, the use of free or cell-based enzymes as
biocatalysts for large-scale industrial processes pose significant drawbacks due to their
incompatibility with reaction conditions that often depart from their physiological states.
However, cells often compartmentalize various biological reactions to address challenges such as
the toxicity of accumulating intermediates, competing reaction pathways and slow turnover rates.
Objective: In this work, we attempt to mimic biological compartmentalization, where structures
such as carboxysomes naturally encapsulate RubisCO and carbonic anhydrase and provide a
protected environment to maximize CO2 assimilation. Methods: To initiate such studies, we
have attempted to encapsulate RubisCO within self-assembled nanotubes. Conditions were
established such that RubisCO was successfully sequestered into a variety of self-assembling
nanotubes. Results : The encapsulated protein was enzymatically active and was clearly
associated with the nanotubes and removed from solution based on a number of criteria.
Conclusion: These nanostructures were also found to enhance the stability of RubisCO toward
proteases and other environmental factors. We expect this research will permit encapsulated
biocatalysts to be useful in scalable CO2 conversions and other processes.