Co-crystal
structure of protein-DNA nanowires. The protein-DNA nanowire
design is
experimentally verified by X-ray crystallography.
Credit: Yun (Kurt)
Mou, Jiun-Yann Yu, Timothy M. Wannier, Chin-Lin Guo
and Stephen L.
Mayo/Caltech
(September 4, 2015) The
ability to custom design biological materials such as protein and DNA opens up
technological possibilities that were unimaginable just a few decades ago. For
example, synthetic structures made of DNA could one day be used to deliver
cancer drugs directly to tumor cells, and customized proteins could be designed
to specifically attack a certain kind of virus. Although researchers have
already made such structures out of DNA or protein alone, a Caltech team
recently created—for the first time—a synthetic structure made of both protein
and DNA. Combining the two molecule types into one biomaterial opens the door
to numerous applications.
A paper describing the so-called hybridized, or multiple
component, materials appears in the September 2 issue of the journal Nature.
Design strategy of
protein-DNA nanowires. The protein-DNA nanowire is
self-assembled
with a computationally designed protein homodimer and
a double-stranded
DNA with the protein binding sites properly arranged.
Credit: Yun (Kurt)
Mou, Jiun-Yann Yu, Timothy M. Wannier, Chin-Lin Guo
and Stephen L. Mayo/Caltech
There are many advantages to multiple component materials,
says Yun (Kurt) Mou (PhD '15), first author of the Nature study. "If your
material is made up of several different kinds of components, it can have more
functionality. For example, protein is very versatile; it can be used for many
things, such as protein–protein interactions or as an enzyme to speed up a
reaction. And DNA is easily programmed into nanostructures of a variety of
sizes and shapes."
But how do you begin to create something like a protein–DNA
nanowire—a material that no one has seen before?
Mou and his colleagues in the laboratory of Stephen Mayo,
Bren Professor of Biology and Chemistry and the William K. Bowes Jr. Leadership
Chair of Caltech's Division of Biology and Biological Engineering, began with a
computer program to design the type of protein and DNA that would work best as
part of their hybrid material. "Materials can be formed using just a
trial-and-error method of combining things to see what results, but it's better
and more efficient if you can first predict what the structure is like and then
design a protein to form that kind of material," he says.