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 Solving the efficiency of Gram-negative bacteria
22.03.2019 | Harvard University

nachricht Bacteria bide their time when antibiotics attack
22.03.2019 | Rice University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: The taming of the light screw

DESY and MPSD scientists create high-order harmonics from solids with controlled polarization states, taking advantage of both crystal symmetry and attosecond electronic dynamics. The newly demonstrated technique might find intriguing applications in petahertz electronics and for spectroscopic studies of novel quantum materials.

The nonlinear process of high-order harmonic generation (HHG) in gases is one of the cornerstones of attosecond science (an attosecond is a billionth of a...

Im Focus: Magnetic micro-boats

Nano- and microtechnology are promising candidates not only for medical applications such as drug delivery but also for the creation of little robots or flexible integrated sensors. Scientists from the Max Planck Institute for Polymer Research (MPI-P) have created magnetic microparticles, with a newly developed method, that could pave the way for building micro-motors or guiding drugs in the human body to a target, like a tumor. The preparation of such structures as well as their remote-control can be regulated using magnetic fields and therefore can find application in an array of domains.

The magnetic properties of a material control how this material responds to the presence of a magnetic field. Iron oxide is the main component of rust but also...

Im Focus: Self-healing coating made of corn starch makes small scratches disappear through heat

Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.

Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...

Im Focus: Stellar cartography

The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.

A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...

Im Focus: Heading towards a tsunami of light

Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.

"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Solving the efficiency of Gram-negative bacteria

22.03.2019 | Life Sciences

Bacteria bide their time when antibiotics attack

22.03.2019 | Life Sciences

Open source software helps researchers extract key insights from huge sensor datasets

22.03.2019 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>