Tip:
Highlight text to annotate it
X
>> The International Space Station is due
to receive another big shipment of supplies later this month
on the next Dragon cargo ship.
It's currently targeted for launch on March 16.
It will carry personal supplies for the crew members as well
as equipment for the station.
This Dragon is also going to carry a number of experiments,
and we're going to be previewing those experiments
in the days leading up to the launch.
One of those new experiments coming up on the Dragon intends
to take advantage of the micro gravity environment
to help develop new drugs to treat Huntington's Disease.
Joining us to talk about it is Gwen Owens.
She's a PhD and MD student at Cal Tech and UCLA respectively.
And she's part of the team on the experiment known
as Crystallization of Huntington Exon 1 using Micro Gravity.
Gwen, could you start by briefly reminding us just what
Huntington's Disease is?
>> Hi. Good morning.
Yes. Huntington's Disease is an incurable fatal
neurodegenerative disease.
It's caused by a gene mutation
that creates an abnormal protein,
which is called "Huntington," which leads to degeneration
of the nervous system.
Huntington's Disease slowly diminishes the affected
individual's ability to walk, talk, and think.
Eventually, the person can't care for him or herself and dies
from medical problems that arise from the affects
of Huntington's on the body.
Each child of a person
with Huntington's Disease has a 50-50 chance
of inheriting the fatal gene, and everyone
who carries the gene will develop the disease.
Huntington's Disease is one
of the more common genetic disorders,
and more than a quarter
of a million Americans have Huntington's Disease or are
at risk of inheriting the disease from an effected parent.
Unfortunately, at present, there's no treatment to stop
or even slow the deadly progression of this disease.
>> Though there's been a lot of research done, and I understand
that researchers think that the answer may be able to found
by successfully crystallizing a certain protein.
Is that something that you can't do on the ground?
>> It's something we haven't been able
to do on the ground yet.
We'd like to determine the three-dimensional structure
of Huntington which is the protein
that causes Huntington's Disease.
To study the Huntington protein, to make drugs against it,
we need detailed three-dimensional structural
information about it.
And one very good way of doing
that is using x-ray crystallography,
which is a technique that let's us see molecules
and locate individual atoms in a protein.
But for studying the structure of abnormal proteins
like Huntington using x-ray crystallography,
we need to produce sufficiently large,
perfect crystals of the protein.
On Earth, however, we haven't been able to grow crystals
for many important proteins including Huntington
because of gravity.
Despite our best efforts,
the Huntington protein has evaded crystallization for more
than a decade; however, there's been good evidence
that crystals grown in micro gravity are able
to reach much larger sizes and more perfect forms
than those grown on earth
because there's no effects of gravity and --
>> I'm sorry.
Go ahead.
>> No. Go ahead.
>> And we've heard for years that we've been growing crystals
for different purposes in space, and so I take it
that that's your experiment is to grow these crystals.
Could you describe what's going to happen
in your experiment once it reaches the station?
>> Sure. Sure.
So we're using a technique that's called
"vapor diffusion" to grow crystals.
It's a technique that can be used both
in micro gravity and on Earth.
In this technique, we have one drop that contains our protein,
our Huntington; and in another drop that's much larger,
we have what's called a precipitant solution.
When these two different solutions can communicate
by vapor diffusion, water can come out of the protein solution
and go into the large precipitant solution.
As this happens, the solution of protein
of Huntington becomes supersaturated,
and when it becomes supersaturated,
it can form crystals.
And so we have a device that is called the high --
"handheld high density protein crystal growth system."
The image is of a small metallic container that holds several
of our sample blocks, 30 different samples in all.
There's a small activation-deactivation tool
that's shown in the left-hand side.
And what happens is that prior to launch,
we have our two solutions -- our large precipitant solution
and a drop of our protein that are kept separate.
It's sent up to the International Space Station,
and there, crew members turn the activation-deactivation switch
so that these two solutions are now in vapor diffusion contact,
and the experiment can begin once it reaches micro gravity.
While it's on the International Space Station,
it's just in a quiescent micro gravity environment,
and then at the end of the experiment,
the astronauts will flip the switch,
the activation-deactivation switch,
to deactivate the experiment, and it will be returned
on the next Dragon cargo ship.
>> So in your case in particular, having a ship
that can bring cargo down to Earth is critical.
>> Absolutely.
There's no way to get data
from our crystallization experiments while aboard the
station, so the Dragon spacecraft is essential
for our experiment to get the crystals down from the station.
>> And once you do, what is the next step in your research?
What do you do with these crystals once you get them?
>> So if we can obtain crystals of Huntington
of sufficient size, which we predict they will be able
to in micro gravity, we test these crystals using x-rays.
So we focus x-rays emerge
from a narrow tube called a colluminator
and strike the crystal.
And crystalline atoms cause the beam of x-rays to diffract
in a number of different directions,
and we record this pattern of defraction.
And when we measure the angles and intensities
of this defracted beam,
we can produce a three-dimensional picture
of the densities of electrons within the crystal.
And then using this electron density map,
we can obtain a very high resolution three-dimensional
protein structure.
>> And with that, hopefully, able to develop something
that will combat the defective gene.
>> Yes, exactly.
Using this 3D structure, we hope to be able
to identify a potential drug treatment
for Huntington's Disease, that we would aim
to identify specific sections of the protein that might interact
with other compounds to produce new targeted drugs
that work efficiently with few side effects, and hopefully,
improve the quality of life for patients around the world
with Huntington's Disease.
>> It's very interesting and it makes a lot
of sense as you explain it.
We'll be looking forward to seeing how it goes.
Thank you for taking a few minutes
to talk with us about it.
>> Thank you, very much for your time.
>> Gwen Owens is a member of the team on the experiment known
as Crystallization of Huntington Exon 1 using Micro Gravity,
which we fly
to the International Space Station later this month
on the next Dragon cargo ship. ------------------------------c756035fce2c--