Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Amphibian Froth

06.10.2008
Unusual linkage pattern in a blue protein found in the foam nests of tropical frogs

An unusual blue protein called ranasmurfin and found in the foam nests of a Malaysian tree frog has aroused the interest of a team of British, Brazilian, and Malaysian researchers led by Alan Cooper at the University of Glasgow and James H. Naismith at the University of St Andrews. The colored portion of the protein contains a previously unknown type of zinc-coordinated linkage between its subunits.

Many tropical frogs protect their sensitive eggs and embryos with a foam. When mating, the female excretes a protein-rich fluid that she, together with the male, whips into a sticky foam nest that is then stuck to a structure or plant overhanging a body of water. These tiny ecosystems contain an entire spectrum of previously unknown proteins and other macromolecules; they stabilize the foam, hold it firmly to its substrate, protect it from microbes and predators, prevent dehydration, and provide an ideal environment for the embryos.

The dark greenish-blue color of the nests of the Malaysian tree frog stems from ranasmurfin. Each monomer of this dimeric protein consists of 113 amino acids that are folded into a novel helical motif and stabilized through a series of cross-linkages, which includes an unusual lysine–tyrosine–quinone linkage. Even more unusual is the linkage between the two monomers, in which two lysine–tyrosine–quinone linkages are bridged by a nitrogen atom. This previously unknown type of linkage forms, together with two histidine groups, the binding site for a zinc ion. With its four ligands, the metal ion is thus in a tetrahedral environment. This structure is the unit responsible for the color (chromophore) of the protein.

Currently, the biological function of ranasmurfin can only be speculated. The scientists believe that this protein, which is present in relatively large amounts in the foam, is involved in the stabilization and adhesion of the foam. Proteins with similar linkages seem to play a role in the stabilization of adhesives and cements from mussels. Blue proteins are rare in nature and the chromophore in ranasmurfin has little in common with other blue-green proteins. The blue color could play a role in camouflaging the nests or protection from the sun.

Biological foams are an interesting source of novel proteins. Unusual variations, such as the linkages in the ranasmurfin chromophore, are often posttranslational, meaning they occur after translation of the genetic code into an amino acid chain, and are thus not predictable by the analysis of DNA sequences alone.

Author: Alan Cooper, University of Glasgow (UK), http://www.chem.gla.ac.uk/staff/alanc/

Title: Unusual Chromophore and Cross-Links in Ranasmurfin: A Blue Protein from the Foam Nests of a Tropical Frog

Angewandte Chemie International Edition 2008, 47, No. 41, 7853–7856, doi: 10.1002/anie.200802901

Alan Cooper | Angewandte Chemie
Further information:
http://pressroom.angewandte.org
http://www.chem.gla.ac.uk/staff/alanc/

More articles from Life Sciences:

nachricht Bolstering fat cells offers potential new leukemia treatment
17.10.2017 | McMaster University

nachricht Ocean atmosphere rife with microbes
17.10.2017 | King Abdullah University of Science & Technology (KAUST)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Ocean atmosphere rife with microbes

17.10.2017 | Life Sciences

Neutrons observe vitamin B6-dependent enzyme activity useful for drug development

17.10.2017 | Life Sciences

NASA finds newly formed tropical storm lan over open waters

17.10.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>