Molecular elasticity may have originated in cnidarian elastomer
Scientists at Heidelberg University have discovered an unusually elastic protein in one of the most ancient groups of animals, the over 600-million-year-old cnidarians. The protein is a part of the “weapons system” that the cnidarians use: a kind of harpoon launched from their body at extremely high speed.
The discovery of the hitherto unknown protein in the freshwater polyp Hydra suggests that the molecular mechanism of elasticity could have originated in the cnidarians and evolved to discharge a deadly weapon. Due to the similarity of the protein’s amino acid sequence to spidroin of spider silk, the researchers from the Centre for Organismal Studies dubbed the elastic protein cnidoin. The results of the research were published in the journal “BMC Biology”.
Elastomeric proteins evolved in a diverse range of animals and often fulfil highly specialised biological functions as the elastin in the pulmonary alveoli of higher vertebrates, the resilin in the wing joints of insects or the spidroin in the threads of spider silk. They give tissues mechanical properties that exceed those of artificial materials.
These proteins, known as elastomers, share a common property – structurally disordered, repetitive protein sequences that store energy when a molecule is stretched which then can be used in the form of a movement after release. These movements can be rhythmical, as in the blood vessels leaving the heart. Or they can be single, explosive movements, as in the jump of a grasshopper.
In their experiments on the freshwater polyp Hydra, the research team of Assistant Professor Dr. Suat Özbek and Prof. Dr. Thomas Holstein at the Centre for Organismal Studies (COS) demonstrated that cnidoin is part of the cnidarian weaponry – the stinging capsules. These organelles help jellyfish, corals and sea anemones capture prey and ward off enemies.
When touched, a tubule is ejected within nanoseconds in a harpoon-like fashion from the interior of the highly pressurised capsule. The discharge of the stinging thread is one of the fastest processes known in the animal kingdom. Its barbed tip injects poisons through the stinging thread that paralyse or kill the attacker or prey within seconds. “Cnidoin is a structural component of the capsule wall, which is elastically stretched prior to discharge and firing of the harpoon,” explains Dr. Özbek.
Together with other researchers in Heidelberg and Munich, the scientists at COS investigated the biomechanical properties of cnidoin. Force measurements were performed on single molecules and computer simulations conducted.
The special properties of the elastic protein are principally responsible for the enormous acceleration of the “harpoon tip” that occurs during the discharge process and, according to Dr. Özbek, exceeds five million g. “The biomechanical properties of cnidoin are comparable to those of other elastomers. However, cnidoin evidences extraordinarily fast recoil, probably due to the extensive cross-linking to the dense capsule wall.”
The researcher points out that the molecular mechanism of elasticity emerged several times in the animal kingdom, independently of each other. “From an evolutionary standpoint, however, cnidoin is oldest elastic protein reported so far,” states Suat Özbek. “We therefore assume that this elasticity originated in the cnidaria and evolved as part of their ‘weapons system’.”
Prof. Dr. Wolfgang Petrich of Heidelberg University's Kirchhoff Institute for Physics and Prof. Dr. Frauke Gräter of the Heidelberg Institute for Theoretical Studies (HITS) also participated in the research, along with physicist Dr. Martin Benoit from LMU Munich.
A. Beckmann, S. Xiao, J.P. Müller, D. Mercadante, T. Nüchter, N. Kröger, F. Langhojer, W. Petrich, T.W. Holstein, M. Benoit, F. Gräter and S. Özbek: A Fast Recoiling Silk-like Elastomer Facilitates Nanosecond Nematocyst Discharge, BMC Biology.2015, 13:3 (16 January 2015), doi: 10.1186/s12915-014-0113-1
Assistant Professor Dr. Suat Özbek
Centre for Organismal Studies
Phone: +49 6221 54-5638
Communications and Marketing
Press Office, phone: +49 6221 54-2311
Marietta Fuhrmann-Koch | idw - Informationsdienst Wissenschaft
New photocatalyst speeds up the conversion of carbon dioxide into chemical resources
29.05.2017 | DGIST (Daegu Gyeongbuk Institute of Science and Technology)
Copper hydroxide nanoparticles provide protection against toxic oxygen radicals in cigarette smoke
29.05.2017 | Johannes Gutenberg-Universität Mainz
The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.
The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
29.05.2017 | Earth Sciences
29.05.2017 | Life Sciences
29.05.2017 | Physics and Astronomy