Designed protein aggregates entrapping carbon nanotubes for bioelectrochemical oxygen reduction.
The engineering of robust protein/nanomaterial interfaces is critical in the development of bioelectrocatalytic systems. We have used computational protein design to identify two amino acid mutations in the small laccase protein (SLAC) from Streptomyces coelicolor to introduce new inter-protein disulfide bonds. The new dimeric interface introduced by these disulfide bonds in combination with the natural trimeric structure drive the self-assembly of SLAC into functional aggregates. The mutations had a minimal effect on kinetic parameters, and the enzymatic assemblies exhibited an increased resistance to irreversible thermal denaturation. The SLAC assemblies were combined with single-walled carbon nanotubes (SWNTs), and explored for use in oxygen reduction electrodes. The incorporation of SWNTs into the SLAC aggregates enabled operation at an elevated temperature and reduced the reaction overpotential. A current density of 1.1 mA/cm(2) at 0 V versus Ag/AgCl was achieved in an air-breathing cathode system. Biotechnol. Bioeng. 2016;113: 2321-2327. © 2016 Wiley Periodicals, Inc.
Department of Chemical Engineering, Columbia University, 500 West 120th Street, New York, New York, 10027.
Kristen E
KE
Garcia
Department of Chemical and Biological Engineering, University of New Mexico, Albuquerque, New Mexico.
Sofia
S
Babanova
Department of Biochemistry, University of Washington, Seattle, Washington.
William
W
Scheffler
Department of Chemical Engineering, Columbia University, 500 West 120th Street, New York, New York, 10027.
Mansij
M
Hans
Department of Biochemistry, University of Washington, Seattle, Washington.
David
D
Baker
Department of Chemical and Biological Engineering, University of New Mexico, Albuquerque, New Mexico.
Plamen
P
Atanassov
Department of Chemical Engineering, Columbia University, 500 West 120th Street, New York, New York, 10027. sbanta@columbia.edu.
Scott
S
Banta
D015374:Biosensing Techniques / Q000295:instrumentation*; D017097:Electric Impedance; D004566:Electrodes; D004574:Electromagnetic Fields; D004867:Equipment Design; D019544:Equipment Failure Analysis; D042845:Laccase / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry*; D066329:Protein Aggregates
D037742:Nanotubes, Carbon; D066329:Protein Aggregates; D042845:Laccase; D010100:Oxygen
laccase; oxygen reduction reaction; protein design; protein/nanomaterial interface; self-assembly