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 NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation

nachricht Pollen taxi for bacteria
18.07.2018 | Technische Universität München

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Machine-learning predicted a superhard and high-energy-density tungsten nitride

18.07.2018 | Materials Sciences

NYSCF researchers develop novel bioengineering technique for personalized bone grafts

18.07.2018 | Life Sciences

Why might reading make myopic?

18.07.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>