Researchers from Rensselaer Polytechnic Institute and the University of Vermont have discovered a key molecular mechanism that allows tiny flies and other "no-see-ums" to whirl their wings at a dizzying rate of up to 1,000 times per second. The findings are being reported in the Oct. 30-Nov. 3 online early edition of the Proceedings of the National Academy of Sciences (PNAS).
"We have determined important details of the biochemical reaction by which the fastest known muscle type -- insect flight muscle -- powers flight," said Douglas Swank, assistant professor of biology at Rensselaer and lead author of the PNAS paper.
The findings will help scientists gain a better understanding of how chemical energy is converted into muscle movements, such as human heart muscle pumping blood. The research also could lead to novel insights into heart disease, and might ultimately serve in the development of gene therapies targeted toward correcting mutations in proteins that detrimentally alter the speed at which heart muscle fibers contract.
Since insects have been remarkably successful in adapting to a great range of physical and biological environments, in large part due to their ability to fly, the research also will interest scientists studying the evolution of flight, Swank noted. The project is supported by a three-year $240,000 grant from the National Institutes of Health and a four-year $260,000 grant from the American Heart Association.
The research is focused on a key component of muscle called myosin, the protein that powers muscle cell contraction. Swank's team focused its efforts on the fruit fly and asked a basic question: Why are fast muscles fast and slow ones slow? The researchers discovered that the reaction mechanism in insect flight muscle on the molecular level is different from how slower muscle types work.
"Most research has focused on slower muscle fibers in larger animals," Swank said. "By investigating extreme examples, e.g. the fastest known muscle type, the mechanisms that differentiate fast and slow muscle fiber types are more readily apparent."
In general, myosin breaks down adenosine triphosphate (ATP), the chemical fuel consumed by muscles, and converts it into force and motion. To do this, myosin splits ATP into two compounds, adenine diphosphate (ADP) and phosphate. Each compound is released from myosin at different rates. In slow-muscle contraction, ADP release is the slowest step of the reaction, but in the fastest muscle fibers, Swank's team has discovered that phosphate release is the slowest step of the reaction.
This finding is significant because the overall chemical reaction rate is set by the slowest step of the reaction. "What we have found is that in the fastest muscle type, ADP release has been sped up to the point where phosphate release is the primary rate-limiting step that determines how fast a muscle can contract," Swank said.
The next step, according to the researchers, is to experiment with other fast muscle types, such as the rattlesnake shaker muscle and fast mammalian muscle fibers. "By broadening our research, we will be able to determine if the phosphate release rate contributes to setting muscle speed in fast muscle types from other species," according to Swank.
Jason Gorss | EurekAlert!
Rutgers scientists discover 'Legos of life'
23.01.2018 | Rutgers University
Researchers identify a protein that keeps metastatic breast cancer cells dormant
23.01.2018 | Institute for Research in Biomedicine (IRB Barcelona)
Physicists have developed a technique based on optical microscopy that can be used to create images of atoms on the nanoscale. In particular, the new method allows the imaging of quantum dots in a semiconductor chip. Together with colleagues from the University of Bochum, scientists from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute reported the findings in the journal Nature Photonics.
Microscopes allow us to see structures that are otherwise invisible to the human eye. However, conventional optical microscopes cannot be used to image...
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
23.01.2018 | Life Sciences
23.01.2018 | Earth Sciences
23.01.2018 | Physics and Astronomy