Page 75 - International Space Station Benefits for Humanity, 3rd edition.

Finding the Keys in Space to
Treat Diseases on Earth
A protein that causes disease and a medicine that Scientists are growing protein
suppresses it operate much like a keyhole and a key. crystals on the ISS to design
Determining the shape of the keyhole by examining the
protein structure can help create a key to fit it—i.e., an keys to fit keyholes for various
effective medicine with few side effects. Scientists are medical conditions on Earth.
growing protein crystals on the ISS to design keys to
fit keyholes for various medical conditions on Earth.
The High-Quality Protein Crystal Growth (PCG)
experiment on the Japanese Experiment Module Kibo
is one example. It expands a partnership between Space Corporation ROSCOSMOS (ROSCOSMOS).
PeptiDream Inc, a Tokyo-based biopharmaceutical When new developments with the private Orbital ATK
company, and the Japan Aerospace Exploration Dragon cargo spacecraft made it possible for users to
Agency (JAXA) to increase by sixfold the experimental choose crystallization temperatures, JAXA launched
protein samples, or keys, investigated. the 4°C (39°F) PCG experiment.
The partners previously crystallized a nonstandard cyclic “Crystallization at 4 degrees C allows crystallization
peptide drug candidate to target the human epidermal of candidate drugs in high demand, such as unstable
growth factor receptor 2 (HER2). About 1 out of every hydrosoluble proteins and membrane proteins,”
5 people with breast cancer makes an excess of HER2 said JAXA’s Masaki Shirakawa. “At 20 degrees C,
protein, which promotes the growth of cancer cells. some proteins just aggregate, and do not crystallize.
Unlike conventional peptide-based drugs, nonstandard Conducting experiments under 4 degrees C opens the
peptides have unlimited potential as novel medicines door to space experiments involving unstable proteins.”
due to their structural stability and longer duration Early analysis indicates the 4°C (39°F) PCG experiment
in the human body. The space-grown crystals had resulted in high-quality crystals of the protein and
substantially higher resolution than those attained on the drug candidate complex, thereby accelerating
the ground. Results clearly showed the potential drug development of the potential drug.
bound to the receptor via an unprecedented binding
mode. These findings are useful to PeptiDream in The agreement between PeptiDream and JAXA
furthering the development of the drug. leverages each partner’s strengths—PeptiDream’s as
a leading drug discovery company, and JAXA’s expertise
JAXA’s previous PCG experiments were conducted in identifying and optimizing crystallization conditions
at 20°C (68°F) through a collaboration with the State
and the technical ability to carry out space experiments.
PeptiDream has established technology that facilitates
quick, inexpensive, large-scale production of a wide
variety of nonstandard peptides.
“At any stage of the drug discovery process, a high-
resolution structure always significantly accelerates
this process and having a 3-D structure is truly
invaluable,” said Patrick Reid, President and CEO
of PeptiDream.
“The crystal structure determined from the crystals
attained from the JAXA-PCG experiment will significantly
accelerate the optimization of these candidates toward
clinical candidates,” said Executive Vice President
Keiichi Masuya.
Kibo and the space station play a key role in allowing
Protein crystals formed in microgravity PeptiDream and JAXA to obtain structural information
in the ISS Kibo module. on target proteins and their drug candidates swiftly and
Image credit: JAXA efficiently, thus aiming to produce new and better drugs
for Japan and the world.

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