Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UK scientists crack lobster shell colour puzzle

29.07.2002


UK researchers announced a first this week when they reported their discovery of how lobsters change colour from the blue-purple of their ocean-floor camouflage to the distinctive orange-red when cooked.



Writing in the journal Proceedings of the National Academy of Science, scientists from Imperial College London, University of Manchester, Daresbury Laboratory and Royal Holloway, University of London describe how they have solved the structure of a key part of the lobster shell protein, Beta-Crustacyanin.

Visualising the key subunit of this large molecule allows them to show how structural changes within it can bend the shape of the colour molecule bound to it, Astaxanthin, to make different colours.


Astaxanthin, a carotenoid, has its light-absorption properties altered by the subunit as it undergoes the bathochromic shift. In its free, un-bound form it is orange, but when tightly held by Crustacyanins clamp-like protein subunits, it is flattened and becomes blue.

The effect of cooking lobster is to denature the Crustacyanin unit so much that it becomes permanently stuck in the free form, coloured orange.

Dr Naomi Chayen of Imperial College London said: “This could lead to an important new use of Astaxanthin as a drug-delivery mechanism for medicines that are insoluble in water, and give designers of new food colourants or dyestuffs an interesting new capability.

“It also concludes painstaking research begun by this UK team in 1995, and finally settles a question which has continued to intrigue biologists since Nobel Prize winner George Wald first drew attention to it in 1948.”

In order to gain insight into the mechanism of the molecules that drive the intriguing colour change, it is necessary to look at their 3 - dimensional structure, preferably by X-ray crystallography which requires crystals.

Initial separation and isolation work by Dr Peter Zagalsky of Royal Holloway, University of London, yielded a sample of highly pure Crustacyanin which was then handed to crystal grower Dr Naomi Chayen of Imperial College London.

Dr Chayen made use of the unique Microbatch method of growing crystals under oil (of which she is a co-developer), after the classic crystallization methods repeatedly failed.

She almost abandoned the experiments to grow the crystals after two months, but her persistence paid off as the solution she had carefully put to one side finally produced beautiful blue crystals after four months.

Team members at University of Manchester led by Professor John Helliwell used X-ray crystallographic techniques, including innovative use of softer X-rays on the Synchrotron Radiation Source at Daresbury Laboratory with Dr Pierre Rizkallah, to establish the B-Crustacyanin structure in detail. The Manchester Structural Chemistry Laboratory then harnessed the crystal structure models to account for the colour change.

The Leverhulme Trust funded the research.

Tony Stephenson | alfa

More articles from Life Sciences:

nachricht Cnidarians remotely control bacteria
21.09.2017 | Christian-Albrechts-Universität zu Kiel

nachricht Immune cells may heal bleeding brain after strokes
21.09.2017 | NIH/National Institute of Neurological Disorders and Stroke

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Comet or asteroid? Hubble discovers that a unique object is a binary

21.09.2017 | Physics and Astronomy

Cnidarians remotely control bacteria

21.09.2017 | Life Sciences

Monitoring the heart's mitochondria to predict cardiac arrest?

21.09.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>