An artist's
rendering of P22-Hyd, a new biomaterial created by encapsulating a
hydrogen-producing
enzyme within a virus shell. | Photo by Trevor Douglas
(January 5, 2015) Combining
bacterial genes and virus shell creates a highly efficient, renewable material
used in generating power from water
Scientists at Indiana University have created a highly
efficient biomaterial that catalyzes the formation of hydrogen -- one half of
the "holy grail" of splitting H2O to make hydrogen and oxygen for
fueling cheap and efficient cars that run on water.
A modified enzyme that gains strength from being protected
within the protein shell -- or "capsid" -- of a bacterial virus, this
new material is 150 times more efficient than the unaltered form of the enzyme.
Illustration
showing the release of NiFe-hydrogenase from inside the virus shell,
or
"capsid," of bacteriophage P22. | Photo by Trevor Douglas
The process of creating the material was recently reported
in "Self-assembling biomolecular catalysts for hydrogen production"
in the journal Nature Chemistry.
"Essentially, we've taken a virus's ability to
self-assemble myriad genetic building blocks and incorporated a very fragile
and sensitive enzyme with the remarkable property of taking in protons and
spitting out hydrogen gas," said Trevor Douglas, the Earl Blough Professor
of Chemistry in the IU Bloomington College of Arts and Sciences' Department of
Chemistry, who led the study. "The end result is a virus-like particle
that behaves the same as a highly sophisticated material that catalyzes the
production of hydrogen."
Trevor Douglas |
Photo by Montana State University
Other IU scientists who contributed to the research were
Megan C. Thielges, an assistant professor of chemistry; Ethan J. Edwards, a
Ph.D. student; and Paul C. Jordan, a postdoctoral researcher at Alios
BioPharma, who was an IU Ph.D. student at the time of the study.
The genetic material used to create the enzyme, hydrogenase,
is produced by two genes from the common bacteria Escherichia coli, inserted
inside the protective capsid using methods previously developed by these IU
scientists. The genes, hyaA and hyaB, are two genes in E. coli that encode key
subunits of the hydrogenase enzyme. The capsid comes from the bacterial virus known
as bacteriophage P22.
The resulting biomaterial, called "P22-Hyd," is
not only more efficient than the unaltered enzyme but also is produced through
a simple fermentation process at room temperature.
The material is potentially far less expensive and more
environmentally friendly to produce than other materials currently used to
create fuel cells. The costly and rare metal platinum, for example, is commonly
used to catalyze hydrogen as fuel in products such as high-end concept cars.