Using an imaging method called atomic force microscopy, Loong achieved two “firsts”: the first direct imaging of individual alpha-tropomyosin molecules, which are very small — roughly 40 nanometers long — and the first demonstrated examples of a measure of the human cardiac protein’s flexibility. From there, he established a baseline of how flexible a normal version of the protein is supposed to be in a healthy human heart.
“This basic research is important to broadening our understanding of how the human heart functions normally at the molecular level,” Loong said. “The flexibility of alpha-tropomyosin dictates how effectively or properly the heart muscle will contract on each beat and has implications for keeping the heart free of cardiovascular disease.
“Before this study, we did not know how flexible this protein was,” Loong said. “Using these results, now we can conduct subsequent studies to compare disease-related mutants of this protein to see how much they deviate from normal versions.”
Loong served as the lead author of the paper “Persistence Length of Human Cardiac a-Tropomyosin Measured by Single Molecule Direct Probe Microscopy,” which was published in the journal PLoS ONE. He conducted the research with physics Professor Huan-Xiang Zhou and biological science Professor P. Bryant Chase, both of Florida State.
When an electrical signal is generated in the heart to make it contract, calcium is released inside each heart muscle cell. The calcium then binds to a protein called troponin, and that triggers the “flexing movement” of alpha-tropomyosin, which allows another protein called myosin — the motor protein — to interact with the troponin/tropomyosin actin filaments. This series of events is what generates the heart’s contraction that pumps blood. A subsequent removal of calcium inside each heart cell is what relaxes the heart, which allows the heart to fill with blood to be pumped on the next beat.
“Alpha-tropomyosin is a key element that makes the calcium signal either turn the heart on, making it contract, or turn it off, making it relax,” Chase said. “There is an optimal range of flexibility of alpha-tropomyosin for the normal heart to function properly. The molecule can be too stiff or it can be too flexible, either of which could lead to cardiovascular disease. What we ultimately think is that evolution has tuned the mechanical properties of these proteins for optimal function in the heart.”
P. Bryant Chase | Newswise Science News
Biochemical 'fingerprints' reveal diabetes progression
22.08.2017 | Umea University
When fish swim in the holodeck
22.08.2017 | University of Vienna
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
22.08.2017 | Life Sciences
22.08.2017 | Life Sciences
22.08.2017 | Life Sciences