Breaking the protein code with the Space Station

When a Russian Progress craft docked with the ISS on 23 August, it brought
Europe’s second scientific experiment to the space station. The Granada
Crystal Box Experiment does not look very impressive from the outside: as
its name suggests, it is a box, and quite a small one — just 13 cm by 13
by 8. On Earth, it weighs about a kilogramme.

On the ISS, of course, it weighs nothing: which is precisely why it is there,
and why it may help European scientists to make a few strides forward in
molecular biology and drug design.

Financed by ESA, the Crystallisation Box Experiment was designed and built
by scientists at the Laboratorio de Estudios Cristalogr·ficos of the
University of Granada in Spain, and like the Advanced Protein Crystallisation
Facility — brought to the station by shuttle mission STS-105 on 10 August —
the equipment is designed to help unravel the structure of protein molecules.

These complex chemicals are the building blocks of life. Essentially,
proteins are long chains and coils of amino acids, themselves relatively
simple substances. Scientists can fairly easily establish a protein’s
chemical make-up. But proteins owe their extraordinary biological abilities
less to their content than to their shape. Their folds and convolutions
provide receptor areas in the molecule that allow them to mediate with
enormous precision in the billions of chemical reactions that keep living
things alive.

To discover a protein’s structure — which could be the key to new drug
treatments — scientists use a technique called X-ray crystallography. And
for that, they need protein crystals — the bigger and more perfect the
better. That’s where the ISS comes in. The weightless environment allows
crystals to form without any interference from gravity-induced convection
currents.

Protein crystallisation experiments have been performed in space for many
years, with varying degrees of success: even in microgravity, the huge
molecules are reluctant to grow crystals large enough for X-ray work back
on Earth. But the scientific team in Granada are hopeful that their
device will succeed where others have failed: the CBE uses a different
crystallisation technique. The saturated solutions of salts and the
protein macromolecules are contained in capillary tubes — a method
impossible on Earth where convection currents prevent crystals growing big
enough for good X-ray results. In space, though, things should be different.

The CBE team will not have too long to wait for their first results. Right
now, their experiment is nestling in a quiet corner of the ISS: it needs
neither power nor attention from the crew. All being well, it will be
returned to Earth on 31 October. And its capillary tubes — which can be
directly X-rayed, without removing their fragile contents — may have some
secrets to reveal.

Europe’s second scientific experiment on the ISS, delivered to by a Russian
Progress craft on 23 August, is designed to help unravel the structure of
protein crystals. Financed by ESA, the Crystallisation Box Experiment was
designed and built at the University of Granada’s Laboratorio de Estudios
Cristalograficos. Granada team hope to succeed where others have failed
using a different crystallisation technique. The saturated solutions of
salts and protein macromolecules are contained in capillary tubes —
impossible on Earth because convection currents prevent the growth of
large enough crystals for X-ray crystallography.

Related News

* First European experiment facility up and running on the ISS

http://www.esa.int/export/esaCP/ESA43I1VMOC_Benefits_0.html

Related Links

* Granada Crystallisation Box Experiment

http://www.spaceflight.esa.int/users/file.cfm?filename=fac-iss-gcb

* Laboratory for Crystallographic Studies (University of Granada)

http://lec.ugr.es/

* Human Spaceflight website

http://www.esa.int/spaceflight

* ESA’s Spaceflight users website

http://www.spaceflight.esa.int/users/index.cfm