>> The next shipment of supplies
for the International Space Station is due to launch
on Sunday, as mentioned,
and that Dragon vehicle will be bringing supplies
for the crew members plus station equipment
and new science experiments.
Among those experiments are some focusing
on protein crystal growth including one known as CPCGHM
for commercial protein crystal growth high-density modified.
The principal investigator is Dr. Larry DeLucas, the Director
of the Center for Structural Biology, at the University
of Alabama at Birmingham, who has a history
of space-based research that includes his flight
as a payload specialist on Space Shuttle Mission STS-50,
the first flight of the United States microgravity laboratory.
I spoke with him recently about this experiment and asked him
to comment on the focus
on membrane proteins in the human body.
We'll listen to that interview now.
This is Mission Control Houston.
>> In our body and bacteria and viruses, there's proteins
that exist in the membranes of these organisms.
And in the human system, there's literally, you know,
thousands of different membrane proteins
and they play key roles biologically
such as signal transduction
when something happens outside a cell,
how does that information get imparted inside the cell
to affect some other function within the cell.
They are critical in many, many of the drugs that we develop
for different diseases.
So the unfortunate part of this is that if you look
at how crystallography is used, we crystallize the protein
that we'd like to determine the structure for
and membrane proteins are probably the most difficult ones
of all to get, not only to get a crystal but to get a crystal
that is of high enough quality
so that we can determine the three-dimensional structure
using x-ray crystallography.
>> We have to make the crystals out of the proteins in order
to study the structure itself and learn
about how it functions exactly.
>> Yeah and that's the, you know, kind of interesting
and it's fun to crystallize a protein
but the easy ones have been done in nature.
>> How do you grow these crystals in space
and what's the station crews' participation or their role
in growing these crystals while they're up there in space?
>> We know from previous experiments
that the crystals grow much, much more slowly.
>> Okay.
>> Because now the only thing that gets molecules
to the crystal surface is just the natural vibration
of molecules, it's called free interface,
well it's just called Fick's law of diffusion.
They just vibrate, bump into each other and make their way
to the crystal but they grow literally in order
of magnitude more slowly than they do here on Earth
which allows the molecule when it comes into the crystal
to align itself more perfectly before the next one comes in
and traps it in a misalignment.
>> Wow, sounds fascinating.
So they form--
>> That's what we're comparing is without, you know,
buoyancy-induced convection, which we get here
on Earth anytime we grow crystals,
by just letting the molecules slowly diffuse to the crystal,
you know, not only, we know we can get better crystals.
The question on this flight and this is why we're flying 100
of very difficult proteins to work with--
>> Okay.
>> What percentage will be better
and how much better will they be.
We want to statistically show, you know,
once and for all the value of doing this
and we have the advantage of a space station
where the crystals will have plenty of time
to grow to their full size.
So we have literally thousands of experiments going up so
that each protein has multiple chances to try
to get the very best crystals.
We're doing this also on the ground
with ground controls using the same proteins, same batch,
everything, everything's identical but we will not know
when it returns in August which came from space
and which are the ground controls.
Everything has a bar code and only one engineer knows,
you know, what's what.
It'll all be mixed together for each protein.
We'll do the entire analysis and when it's done,
only when we're completely finished will it be revealed
which came from space and ground.
That way we eliminate any perceived bias
that a scientist may choose a better crystal for space just
to make it look better.
>> One other question that I would
like to ask is why are the space-grown crystals
so important to have for research in the disease process
and the drug development?
Can you explain what the importance is for us?
>> Sure. At the beginning and I want to point that out,
it's one of the first steps, the first step in drug development,
you know after you know the protein target,
is to design a potential drug, right,
that will interact with that protein.
By having the structure, it makes it go much faster
and usually you get a more effective drug
with fewer side effects and there are many examples,
not from space but from just ground-based research
where drugs were developed using the structure of a protein.
It's sort of like if you had to design a key, right,
that would open my car door that's locked
in the parking lot, you know,
a locksmith has a key that'll open all the car doors.
But if I showed them the structure of my lock,
he can make a key that would only unlock my car door.
By having the structure of the protein,
it helps you make a drug that's more specific
so it interacts just with my protein and hopefully not others
in our body because we literally have
about a half million different proteins in our body.
When these drugs interact with proteins
that you don't want them to, that's how you often get,
you know, unwanted side effects.
>> Very interesting.
Again, thank you, Larry for taking the time to talk with me.
Good luck in the continued research and thanks a lot.
>> Okay, you're very welcome. ------------------------------0ba9768ddd6a--