Recent computer simulations show how, for the first time, two knots on a DNA strand can interchange their positions, with one knot growing in size and the other diffusing along the contour of the first. This swapping of positions on a DNA strand may also happen in living organisms, and the mechanism may play an important role in future technologies such as nanopore sequencing.
An international collaboration of researchers have unlocked the secret behind the activation of the Ras family of proteins, one of the most important components of cellular signaling networks in biology and major drivers of cancers that are among the most difficult to treat. To make the discovery, they performed single molecule studies of Ras activation in a membrane environment.
Researchers in Sweden have headed a study that provides new knowledge about the EphA2 receptor, which is significant in several forms of cancer. The researchers employed the method of DNA origami, in which a DNA molecule is shaped into a nanostructure, and used these structures to test theories about cell signalling.
Researchers have already used molecular rotors as viscosity sensor probes in live cells, but a recent study in Singapore is the first to report on the use of fluorescent molecular rotors to study critical protein interactions.
Scientists at Scripps Institution of Oceanography have conducted the most detailed examination of green fluorescent proteins (GFPs) in lancelets, marine invertebrates also known as “amphioxus.” They have deciphered the structural components related to fluorescence and have found that only a few key structural differences at the nanoscale allows the sea creature to emit different brightness levels.
Wyatt Technology Corp. has highlighted a recently authored study that outlines the advantages of quantifying protein-protein interactions (PPI) using automated dynamic light scattering (DLS) in high-throughput screening (HTS) mode to identify promising candidates for drug-like properties. Automated DLS helps establish the suitability of formulations before entering extended stability studies.
Many enzymes work only with a co-trainer, of sorts. Scientists in Germany have shown what this kind of cooperation looks like in detail using a novel methodology applied to the heat shock protein Hsp90, which controls the proper folding of other proteins. Together with a second molecule, the co-chaperone P23, it splits the energy source ATP to yield the energy it needs to do its work.
Researchers have developed new methods to trace the life history of individual cells back to their origins in the fertilized egg. By looking at the copy of the human genome present in healthy cells, and by looking at the numbers and types of mutations in a cell's DNA, biologists in the U.K. have been able to build a picture of each cell's development from the early embryo on its journey to become part of an adult organ.
Optogenetics relies on light-sensitive proteins that can suppress or stimulate electrical signals within cells. This technique requires a light source to be implanted in the brain, where it can reach the cells to be controlled. Massachusetts Institute of Technology engineers have now developed the first light-sensitive molecule that enables neurons to be silenced noninvasively, using a light source outside the skull.
For the first time, the genome of the electric eel has been sequenced. This discovery has revealed the secret of how fishes with electric organs have evolved six times in the history of life to produce electricity outside of their bodies. This research has shed light on the genetic blueprint used to evolve these complex, novel organs.
Genomic sequencing is supposed to reveal the entire genetic makeup of an organism. The technology can be used to analyze a disease-causing bacterium to determine how much harm it is capable of causing. But new research at Rockefeller Univ. suggests that current sequencing protocols overlook crucial bits of information: isolated pieces of DNA floating outside the bacterial chromosome, the core of a cell’s genetic material.
Trillions of bacteria live in and on the human body; a few species can make us sick, but many others keep us healthy by boosting digestion and preventing inflammation. Although there's plenty of evidence that these microbes play a collective role in human health, we still know very little about most of the individual bacterial species that make up these communities.
Measurements taken at the molecular scale have, for the first time, confirmed a key property that could improve our knowledge of how the heart and lungs function. Univ. of Washington researchers have shown that a favorable electrical property is present in a type of protein found in organs that repeatedly stretch and retract, such as the lungs, heart and arteries.
The molecular building blocks that make up DNA absorb ultraviolet light so strongly that sunlight should deactivate them, yet it does not. Now, scientists at SLAC National Accelerator Laboratory have made detailed observations of a “relaxation response” that protects these molecules, and the genetic information they encode, from UV damage.
Ribosomes are responsible for the production of the wide variety of proteins that include enzymes. But until now researchers had not uncovered all of the details of how the proteins that are used to construct ribosomes are themselves produced. Biologists in California now say they have found the “missing link” in the chemical system that allows ribosomal proteins to be synthesized.
Researchers at The Johns Hopkins Univ. report they have deciphered the inner workings of a protein called YiiP that prevents the lethal buildup of zinc inside bacteria. They say understanding YiiP's movements will help in the design of drugs aimed at modifying the behavior of ZnT proteins, eight human proteins that are similar to YiiP, which play important roles in hormone secretion and in signaling between neurons.
HIV-1, the virus responsible for most cases of AIDS, is a very selective virus. It doesn’t readily infect species other than its usual hosts. While this would qualify as good news for most mammals, for humans this fact has made the search for effective treatments and vaccines for AIDS that much more difficult; without an accurate animal model of the disease, researchers have had few options for clinical studies of the virus.
Think of the human body as an intricate machine whose working parts are proteins: molecules that change shape to enable our organs and tissues to perform tasks such as breathing, eating or thinking. Of the millions of proteins, 500 in the kinase family are particularly important to drug discovery. Kinases are messengers: They deliver signals that regulate and orchestrate the actions of other proteins.
Researchers from North Carolina State Univ. have developed a technique to control populations of the Australian sheep blowfly—a major livestock pest in Australia and New Zealand—by making female flies dependent upon a common antibiotic to survive.
Researchers at the Univ. of Michigan have obtained the first 3-D snapshots of the "assembly line" within microorganisms that naturally produces antibiotics and other drugs. Understanding the complete structure and movement within the molecular factory gives investigators a solid blueprint for redesigning the microbial assembly line to produce novel drugs of high medicinal value.
Nanoengineers at UC San Diego have developed a nanoshell to protect foreign enzymes used to starve cancer cells as part of chemotherapy. Enzymes are naturally smart machines that are responsible for many complex functions and chemical reactions in biology. However, despite their huge potential, their use in medicine has been limited by the immune system, which is designed to attack foreign intruders.
How does a stem cell decide what path to take? In a way, it’s up to the wisdom of the crowd. The DNA in a pluripotent stem cell is bombarded with waves of proteins whose ebb and flow nudge the cell toward becoming blood, bone, skin or organs. A new theory by scientists at Rice Univ. shows the cell’s journey is neither a simple step-by-step process nor all random.
Nanopores may one day lead a revolution in DNA sequencing. By sliding DNA molecules one at a time through tiny holes in a thin membrane, it may be possible to decode long stretches of DNA at lightning speeds. Scientists, however, haven’t quite figured out the physics of how polymer strands like DNA interact with nanopores.
After a large stroke, motor skills barely improve, even with rehabilitation. An experiment conducted on rats demonstrates that a course of therapy combining the stimulation of nerve fiber growth with drugs and motor training can be successful. The key, however, is the correct sequence: Paralyzed animals only make an almost complete recovery if the training is delayed until after the growth promoting drugs have been administered.
Researchers at the Univ. of Tennessee (UT) are a step closer to creating a prophylactic drug that would neutralize the deadly effects of the chemical weapons used in Syria and elsewhere. Jeremy Smith, UT-ORNL Governor’s Chair and an expert in computational biology, is part of the team that is trying to engineer enzymes—called bioscavengers—so they work more efficiently against chemical weapons.