Tag: "bond" at biology news

Simulations unravel outer membrane transport mechanism

...hers addressed two key questions: First, could the bond between TonB and the luminal domain withstand the force needed to pull the luminal domain downward, away from the barrel" Second, how does the luminal domain respond to force in order to expose a permeation pathway through the barrel" In the first...

Scientists see DNA get 'sunburned' for the first time

...hymine bases are lined up in just the right way to bond when the UV hits, or they're not. "This insight explains why some pairs of thymine bases get damaged more frequently than others, and it suggests that scientists can understand damage patterns to DNA by studying the factors that influence how the ...

Changes in amino acids in the 1918 influenza virus cut transmission

...es in the cell surface—one is through an alpha-2,6 bond and another is through an alpha-2,3 bond. Hemagglutinins from avian influenza virus prefer binding to alpha 2-3 sialic acids, while hemagglutinins from human influenza viruses prefer binding to alpha 2-6 sialic acids, which are highly abundant in th...

Scientists unveil piece of HIV protein that may be key to AIDS vaccine development

...quiring a shape change in gp120 to create a stable bond between the two molecules. Essentially, the scientists found that the initial point of CD4 contact is a site of gp120 weakness because it is the site of recognition—called an epitope—for b12. "One of our primary goals is to develop HIV vaccines th...

RNA enzyme structure offers a glimpse into the origins of life

...of such a molecule--a "ligase" reaction creating a bond between two RNA subunits. Robertson obtained the ligase ribozyme through a kind of test-tube evolution when he was a graduate student at the University of Texas, Austin, working in the lab of biochemist Andrew Ellington. Starting with a mixture o...

FSU researchers determine a critical factor in workings of proteins

...s know that a better understanding of how proteins bond could lead to more effective treatments for genetic disorders and other life-threatening conditions. Now, a pair of Florida State University researchers' new theory has been proven to accurately predict the association rate for proteins. Their theor...

Chemical switch triggers critical cell activities

...chemical link between molecules called a thioester bond acts like a switch to control the handoff of a pro...yme called E2. When attached to E2, this thioester bond allows E2 to bind to a third enzyme called E3, which then helps E2 hand NEDD8 off to the ultimate ta...

Nobel Laureate finds 'elegant' explanation for DNA transcribing enzyme's high fidelity

...phate, the chemical constituent that must have its bond broken in order for the NTP to join the RNA chain ...ing suggested the side chain acts as a trigger for bond formation. The whole decision-making process occurs extremely rapidly, he added, on the order of p...

The power of one: A simpler, cheaper method for cell fusion

...icrochip. Prior to fusion, cells are engineered to bond to one another by using a minor chemical treatment. Cells are first placed in an aqueous chamber within the chip, where they pair off. In contact with one another but not yet fused, the cells flow towards the only exit, which is a miniscule gap that ...

Electric jolt triggers release of biomolecules, nanoparticles

...attached to each electrode. The current caused the bond between the sulfur atoms and the gold platform to break, setting free the tethered molecule. In theory, the researchers said, this technique could be incorporated into a biocompatible implant chip that would release medicine inside a patient on com...

UVa researchers seek to unlock broccoli's cancer fighting secret

...eton found that nutrients in broccoli unexpectedly bond with a specific enzyme in cells. This enzyme had been clearly linked to inflammatory disease processes, but Cross solidified a link with cancer when she found that mice who did not have the gene for this enzyme developed far fewer cancers when given ...

Two-faced protein can stop metastasis or promote it, researchers say

...ed "mesenchymal" cadherins, which provide a looser bond between the cells that sparsely populate the connective tissue. "Collagen usually provides the strength to the connective tissue, so tight cell-cell adhesion is not that important," he says. Sometimes, such as during human development or wound repai...

New roles for growth factors: Enticing nerve cells to muscles

... scientists could only speculate how the invisible bond was formed. "The question was how do these motor neurons know where to go," says Pfaff. "It would be a disaster if you wanted to move your arm and instead bent your back." Earlier studies suggested that muscles lining the spine sent out chemical cu...

Smooth sailing: 'cruise ship virus' tackled by UH, Baylor College of Medicine

...human immune system creates antibody proteins that bond only with proteins that are specific to that disea...but if the virus is present in the sample, it will bond with the antibody and remain on the slide. The next step of the test relies on retroreflectors, ...

Tiny shock absorbers help bacteria stick around inside the body

...briae coils are compressed, keeping tension on the bond between the bacterium and the mucous membrane. "...which the sticky protein tip forms the most stable bond with the surface. Thus, the mechanical and adhesive features of the system evolved together to help ...

Scientists design potent anthrax toxin inhibitor

...g sites of the PA molecule, which permits a firmer bond between the two, explains Dr. Kane. When the inhibitor is bound tightly to PA, the subsequent steps of enzyme entry cannot occur and the toxin is effectively neutralized. The investigators tested the anthrax inhibitor in rats. When given in relativ...

Cellular scale drug delivery from the inside out

...ase externally." Lin explained that the chemical bond holding the cap in place can be engineered to be unphased by chemicals present in normal cells. However, in cancer cells these chemicals, such as antioxidants, appear in much higher concentrations and would break the bonds on the caps and release the...

ASU researchers 'wire' DNA to identify mutations

...echnique, chemical linker groups that form a tight bond with gold electrodes are attached to the ends of DNA. A drop of a DNA solution is then placed between the two electrodes. The DNA sticks to the surface of the electrodes spontaneously. As the tip is pulled away and the two electrodes teased apart, ...

Scientists get first glimpse at how plants, most animals repair UV-damaged DNA

...A molecule become excited. Sometimes an accidental bond forms between them. The bond is called a photo-lesion, and can lead to a kind of molecular injury called a dimer. Dimers prevent ...

Immune system has evolved to prevent autoimmune disease

...bodies that are statistically likely to mistakenly bond with healthy proteins slightly less than one in a trillion times, meaning that on average, they recognize only invading pathogens. ...

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