[ Music ]
>> Well, this experiment has been a long time coming.
We've been growing protein crystals in microgravity.
We being many investigators all over the world actually.
But many in the United States for many years.
It started in 1985 and we know, at least many of us feel,
one of the reasons we often get crystals grown of higher quality
and these are crystals
of important proteins biologically is
because they grow much more slowly
in a microgravity environment compared
to what you would see here with one G on Earth.
But there's another theory
as to why the crystals are often better.
And that theory is that in microgravity
because you have no buoyancy induced convection or movement
of the solution due to gravity, in microgravity the only thing
that makes a big protein molecule move is its vibration.
Random diffusion it's called.
And so when you purify a protein for one
of these crystallization studies you always have a population
of the single protein.
We call that the monomer.
But also there are aggregates, the protein is kind of stuck
to itself as a dimer or a trimer,
larger populations just stuck together
and they get incorporated into the crystal and cause defects.
That hurts the quality of the crystal when we expose it
to an x-ray beam and the whole purpose
of this experiment ultimately is to take crystals grown
in space back to Earth and expose them to x-rays
and from that, we get what's called a diffraction pattern
that leads to the ultimate three dimensional atomic structure
of that protein.
With the situation in microgravity,
but where a crystal grows based on molecules diffusing,
based on this random diffusion to the surface,
without convection because you have microgravity,
without any flow in there, the molecules of a monomer are going
to move much faster to the growing crystal
than a dimer or larger aggregates.
Therefore, microgravity is acting like a filter.
It's bringing monomers to the crystal
and excluding the larger aggregates simply
because they move so much slower than the monomer.
And, therefore, there are fewer defects in the crystal all
of which leads to a more accurate three dimensional
structure of the protein.
When I was a student, to determine the structure
of a protein, you needed a very powerful super computer
and it took to determine that structure, ten years.
So you didn't want -- you didn't want your career to be based
on determining one structure.
But today if we have high quality crystals
on a desktop computer --
first of all, we collect the data literally in one hour.
All of the x-ray data from a protein crystal,
sometimes in ten minutes; okay?
And from that data, that night,
we can see the structure in one day.
And so it's revolutionized this field
where now all pharmaceutical companies would love
to have the structure of the protein
that they're developing drugs to target.
If they don't have good crystals unfortunately,
they still can't get that structure.
And then they have to develop drugs the old fashion way
which is more time consuming, less accurate.
And the old fashion way is you just test literally millions
of compounds hoping one of them will have an affect
on the protein.
What happened in our experiment is the experiment was activated
and I think it was about two and-a-half
to three hours later we started
to see very small crystals forming
in some of the capillaries.
And now a day later, you know, we see crystals
in pretty much all the capillaries.
They've all grown to fairly large size.
Certainly large enough
to collect wonderful x-ray data sets.
What I'm most excited about with this particular experiment is
when I give presentations at crystallography conferences,
when I'm asked, yes, we know you get better crystals,
many people have experienced that
and it's helped get new structures but why.
I think this experiment is going to provide that answer
and that really is what my colleagues want to know.
The Glenn Research Center has been instrumental
in performing these experiments.
First of all, you know,
the folks here really understand what I wanted as a scientist
to glean from these experiments.
And even when I'm not here, it's like I am here.
They're carrying on the experiments through the night.
They're working in shifts.
And these crystals, of course, are --
started growing within hours after --
after the experiment was activated
and they started immediately imaging the crystals both
with light microscopy and florescence.
The florescence is going to be the key in the end telling us
if some of the aggregate is getting into these crystals
and not only that, it's going to tell us the percentage that gets
into the crystals in microgravity, if any.
Right now we're seeing very little florescence
which is a very good sign that microgravity is acting
as a filter compared to what we've seen
in control experiments done on Earth.
So that the whole community will better understand why this is
such an important platform for protein crystallization.