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Wuhan, China

News Article
Site: http://phys.org/biology-news/

A five-year research partnership between the London School of Hygiene & Tropical Medicine and the University of California, Los Angeles (UCLA) has revealed the atomic-level structure of the bluetongue virus (BTV), a disease that has killed an estimated two million cattle in Europe over the past two decades. The results are published in the journal Nature Structural & Molecular Biology. Led by Polly Roy, Professor of Virology and Wellcome Trust Senior Investigator at the London School of Hygiene & Tropical Medicine, the research shows the atomic detail of the individual components of the virus particle, and how these function biologically at different levels of acidity (pH). The team used cutting-edge cryo electron microscopy from the Electron Imaging Center for Nanomachines, led by Dr Hong Zhou, at UCLA's California NanoSystems Institute. With this technology they demonstrated how the virus enters cells to initiate infection via a two-stage process, and how the different molecular components fit together. This new understanding will enable researchers to develop new vaccines with broader protection against BTV and related viruses. Viruses establishing infection in host cells is a highly coordinated process. The molecular and chemical details are relatively clear for enveloped viruses, such as influenza, HIV and herpes, but up to now the mechanisms for cell entry of non-enveloped viruses, such as BTV and others, had not been well understood. Over the past decade Professor Roy has undertaken the first complete molecular understanding of BTV. This includes its replication cycle from virus entry via genome replication to virus assembly and structure, cell-to-cell transmission, and the engagement of the virus particle with the host cell. Professor Roy said: "We are delighted with these results, which show the virus in the highest possible detail at different pH levels. This represents a key piece in the puzzle and a significant step forward for understanding molecular structures and mechanisms in this family of viruses. We hope it will enable the design of specific anti-viral agents and new and efficient vaccines for the control of bluetongue and related viral infections of animals and humans". This work also has promising implications for understanding similar human and animal pathogenic viruses, such as rotaviruses and the Rift Valley fever virus. Explore further: The way to a virus' 'heart' is through its enzymes More information: Xing Zhang et al. Atomic model of a nonenveloped virus reveals pH sensors for a coordinated process of cell entry, Nature Structural & Molecular Biology (2015). DOI: 10.1038/nsmb.3134


News Article
Site: http://www.biosciencetechnology.com/rss-feeds/all/rss.xml/all

Bluetongue disease is a viral infection that has killed approximately 2 million cattle in Europe over the past two decades. A new study has revealed the atomic structure of the Bluetongue virus, including the means by which it infects healthy host cells. Scientists hope to use this information to aid in the creation of vaccines and drug treatments for bluetongue disease. A team led by Hong Zhou, a professor of microbiology, immunology and molecular genetics and faculty director of the Electron Imaging Center for Nanomachines at UCLA’s California Nanosystems Institute, collaborated on the research with a team led by Polly Roy, professor of virology at the London School of Hygiene and Tropical Medicine. The research was published in the journal Nature Structural and Molecular Biology. Using cryo-electron microscopy, the researchers discovered the Bluetongue virus’s two-step process for infecting healthy cells. The virus has sensor proteins on its surface that detect changes in the acidity of its environment. When these proteins sense higher acidity caused by proximity to the target cell, the virus unfurls a protein structure that penetrates the outer membrane of the cell and anchors to it, causing infection. The scientists confirmed this mechanism by lowering the acidity around the virus, which caused the protein structure to detach and refold. “The advantage we have with cryo-electron microscopy is its ability to resolve three-dimensional structures of nanoscale objects in their native environments. This ability, with the revolutionary technology for counting electrons, enables us to collect vast data that we use to reconstruct three-dimensional images of these biological structures, often for the first time,” Zhou said. “We are delighted with these results, which show the virus in the highest possible detail at different pH levels,” Roy said. “This represents a key piece in the puzzle and a significant step forward for understanding molecular structures and mechanisms in this family of viruses. We hope it will enable the design of specific antiviral agents and new and efficient vaccines for the control of bluetongue and related viral infections of animals and humans.” The study’s lead author is Xing Zhang, scientific director of the Electron Imaging Center for Nanomachines. This research was supported by the National Institutes of Health, the National Science Foundation, UCLA and the Wellcome Trust, UK.


News Article
Site: http://www.cemag.us/rss-feeds/all/rss.xml/all

Gardeners often use sheets of plastic with strategically placed holes to allow their plants to grow but keep weeds from taking root. Scientists from UCLA’s California NanoSystems Institute have found that the same basic approach is an effective way to place molecules in the specific patterns they need within tiny nanoelectronic devices. The technique could be useful in creating sensors that are small enough to record brain signals. Led by Paul Weiss, a distinguished professor of chemistry and biochemistry, the researchers developed a sheet of graphene material with minuscule holes in it that they could then place on a gold substrate, a substance well suited for these devices. The holes allow molecules to attach to the gold exactly where the scientists want them, creating patterns that control the physical shape and electronic properties of devices that are 10,000 times smaller than the width of a human hair. A paper about the work was published in the journal ACS Nano. “We wanted to develop a mask to place molecules only where we wanted them on a stencil on the underlying gold substrate,” Weiss says. “We knew how to attach molecules to gold as a first step toward making the patterns we need for the electronic function of nanodevices. But the new step here was preventing the patterning on the gold in places where the graphene was. The exact placement of molecules enables us to determine exact patterning, which is key to our goal of building nanoelectronic devices like biosensors.” With the advance, making nanoelectronic and nanobioelectronic devices could be much more efficient than current methods of molecular patterning, which use a technique called nanolithography. Weiss said that could be especially useful for scientists who are trying to place molecular sensors on the surface of gold or other nanomaterials that are used for their sensitivity and selectivity but difficult to work with because of their size. Neurosensors that could measure brain cell and circuit function in real time could reveal new insights into diseases like autism and depression. Ultimately, Weiss said, the researchers hope to be able to stimulate individual brain circuits using sensors so they can predict key chemical differences between function and malfunction in the brain. This knowledge could then be used to develop targets for new generations of treatments for neurological diseases. The paper’s other authors were John Thomas, Shan Jiang, Nathan Weiss, and Xiangfeng Duan of UCLA, and Matthew Gethers and William Goddard III of Caltech. Research for the study was conducted in the Electron Imaging Center for Nanomachines and the Nano and Pico Characterization Laboratory, which are both parts of the California NanoSystems Institute. The research was supported by the U.S. Department of Energy, the National Science Foundation, the Caltech EAS Discovery Fund, and UCLA.


News Article
Site: http://www.biosciencetechnology.com/rss-feeds/all/rss.xml/all

A team of researchers from the California NanoSystems Institute at UCLA has found a new way to use enzymes to remove pollutants from water that is cost- and energy-efficient, able to remove multiple pollutants at once, and minimizes risks to public health and the environment. The advance could be an important new step in the effort to satisfy the world’s need for clean water for drinking, irrigation and recreational use. Current methods require multiple steps and involve chemicals that react to heat, sunlight or electricity. Scientists previously had shown that polluted water could be cleaned using enzymatic activities of naturally occurring bacteria and fungi, which breaks down pollutants into their harmless chemical components. But that method carries the risk of releasing dangerous organisms into the water. The new UCLA technique, developed by a team led by Shaily Mahendra, a UCLA associate professor of civil and environmental engineering, and Leonard Rome, a professor of biological chemistry and associate director of CNSI, is a variation of that method. The researchers put enzymes into nanoscale particles called “vaults,” then deposit the tiny particles into polluted water. Their method is described in an article published in ACS Nano. Mahendra said microbial processes in water that are part of the natural system of biodegradation would eventually break down pollution in our water, but only over a very long period. “Natural microbes are why the world isn’t still covered with dinosaur droppings,” Mahendra said. “But we don’t have the time or room on our planet to ignore contaminated lakes and rivers for a couple of million years while nature does the work.” Nanoscale vaults are tiny particles — just billionths of a meter across — that are shaped like beer kegs. Mahendra said the new method is effective because the vaults protect the enzymes, keeping them intact and potent when placed in the contaminated water. The scientists tested the method using an enzyme called manganese peroxidase. They found that over a 24-hour period the vaults removed three times as much phenol from the water as the enzyme did when it was dropped into the water without using vaults. They also discovered that because the manganese peroxidase remained stable inside of the vaults, it was still able to remove phenol from the water after 48 hours. Free manganese peroxide was completely inactive after 7 1/2 hours. Vault nanoparticles, which are constructed of proteins and are present in the cells of nearly all living things, were discovered by Rome and Nancy Kedersha, his then-postdoctoral student, in the 1980s. Each human cell contains thousands of vaults, which themselves contain other proteins. But Rome and his colleagues eventually devised a method for building empty vaults that could be used to deliver drugs to specific cells the body to fight cancer, HIV and other diseases. The research contributes to the goals of UCLA’s Sustainable L.A. Grand Challenge, a campuswide initiative to transition the Los Angeles region to 100 percent renewable energy, local water and enhanced ecosystem health by 2050. Mahendra is also helping develop the work plan for Sustainable L.A. Mahendra said the new technique could be scaled up within a few years for commercial use in polluted lakes and rivers, and vaults could be added to membrane filtration units and easily incorporated into existing water treatment systems. Vaults containing several different biodegrading enzymes could potentially remove several contaminants at once from the same water source. They would be unlikely to pose risks to humans or the environment, Rome said, because vaults grow in the cells of so many species. The vaults containing manganese peroxidase used for the new study were built by a team led by Valerie Kickhoefer, an associate researcher working with Rome. Also contributing to the study were first author Meng Wang, a graduate student in Mahendra’s lab, and UCLA staff research associate Danny Abad. Electron microscopy for the study was conducted in CNSI’s Electron Imaging Center for Nanomachines. The research was supported by the Strategic Environmental Research and Development Program (award ER-2422) and the UCLA department of civil and environmental engineering.


News Article
Site: http://phys.org/nanotech-news/

The advance could be an important new step in the effort to satisfy the world's need for clean water for drinking, irrigation and recreational use. Current methods require multiple steps and involve chemicals that react to heat, sunlight or electricity. Scientists previously had shown that polluted water could be cleaned using enzymatic activities of naturally occurring bacteria and fungi, which breaks down pollutants into their harmless chemical components. But that method carries the risk of releasing dangerous organisms into the water. The new UCLA technique, developed by a team led by Shaily Mahendra, a UCLA associate professor of civil and environmental engineering, and Leonard Rome, a professor of biological chemistry and associate director of CNSI, is a variation of that method. The researchers put enzymes into nanoscale particles called "vaults," then deposit the tiny particles into polluted water. Their method is described in an article published in ACS Nano. Mahendra said microbial processes in water that are part of the natural system of biodegradation would eventually break down pollution in our water, but only over a very long period. "Natural microbes are why the world isn't still covered with dinosaur droppings," Mahendra said. "But we don't have the time or room on our planet to ignore contaminated lakes and rivers for a couple of million years while nature does the work." Nanoscale vaults are tiny particles—just billionths of a meter across—that are shaped like beer kegs. Mahendra said the new method is effective because the vaults protect the enzymes, keeping them intact and potent when placed in the contaminated water. The scientists tested the method using an enzyme called manganese peroxidase. They found that over a 24-hour period the vaults removed three times as much phenol from the water as the enzyme did when it was dropped into the water without using vaults. They also discovered that because the manganese peroxidase remained stable inside of the vaults, it was still able to remove phenol from the water after 48 hours. Free manganese peroxide was completely inactive after 7 1/2 hours. Vault nanoparticles, which are constructed of proteins and are present in the cells of nearly all living things, were discovered by Rome and Nancy Kedersha, his then-postdoctoral student, in the 1980s. Each human cell contains thousands of vaults, which themselves contain other proteins. But Rome and his colleagues eventually devised a method for building empty vaults that could be used to deliver drugs to specific cells the body to fight cancer, HIV and other diseases. The research contributes to the goals of UCLA's Sustainable L.A. Grand Challenge, a campuswide initiative to transition the Los Angeles region to 100 percent renewable energy, local water and enhanced ecosystem health by 2050. Mahendra is also helping develop the work plan for Sustainable L.A. Mahendra said the new technique could be scaled up within a few years for commercial use in polluted lakes and rivers, and vaults could be added to membrane filtration units and easily incorporated into existing water treatment systems. Vaults containing several different biodegrading enzymes could potentially remove several contaminants at once from the same water source. They would be unlikely to pose risks to humans or the environment, Rome said, because vaults grow in the cells of so many species. The vaults containing manganese peroxidase used for the new study were built by a team led by Valerie Kickhoefer, an associate researcher working with Rome. Also contributing to the study were first author Meng Wang, a graduate student in Mahendra's lab, and UCLA staff research associate Danny Abad. Electron microscopy for the study was conducted in CNSI's Electron Imaging Center for Nanomachines. The research was supported by the Strategic Environmental Research and Development Program (award ER-2422) and the UCLA department of civil and environmental engineering. Explore further: Researchers design unique method to induce immunity to certain STDs More information: Meng Wang et al. Vault Nanoparticles Packaged with Enzymes as an Efficient Pollutant Biodegradation Technology, ACS Nano (2015). DOI: 10.1021/acsnano.5b04073

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