To clarify the underlying mechanisms of the FLASH effect, in which the delivery of ultrafast, high-intensity doses of radiation to tumors counterintuitively reduces damage to surrounding healthy cells, researchers directly compared the oxidative effects of conventional and FLASH techniques using x-ray footprinting at the ALS. Read more »
ALS Work Using X-Ray Footprinting
In x-ray footprinting (XFP), x-rays traveling through a solution generate hydroxyl radicals, which then modify the amino acids of any proteins in the solution that are solvent accessible. They don’t modify the ones that aren’t solvent accessible, which then creates a map of all the solvent-accessible areas on a protein. Highly complementary to crystallography, one of its main advantages is that it doesn’t require a crystal. Another benefit is that it can be done at close to physiological conditions, which gives researchers a more real-life representation of the protein. Read more…
Structural Investigation of Therapeutic Antibodies Using Hydroxyl Radical Protein Footprinting Methods
Well-known high-resolution structural methods are often used to characterize antibody structures, but many require specialized sample preparation that may perturb antibody structure. We describe here the relatively new method of hydroxyl radical protein footprinting, a solution-state method that can provide structural and kinetic information on antibodies or antibody–antigen interactions useful for therapeutic antibody design. Read more »
Inhalable COVID-19 Protection via Synthetic Nanobodies
Protein structures obtained in part at the ALS helped researchers to increase the potency of simplified antibodies (nanobodies) designed to neutralize SARS-CoV-2. Stable enough to be used in inhalers or nasal sprays, the nanobodies offer a new option, aside from injected vaccines, for COVID-19 prevention and treatment. Read more »
How Light-Harvesting Bacteria Toggle Off and On
Researchers clarified the atomic-level mechanism that enables bacteria to switch light harvesting off and on in response to potentially damaging overexposure to light. The results could have long-range implications for artificial photosynthesis and optogenetics—the use of light to selectively activate biological processes. Read more » 
X-Ray Footprinting Solves Mystery of Metal-Breathing Protein
Scientists have discovered the details of an unconventional coupling between a bacterial protein and a mineral that allows the bacterium to breathe when oxygen is not available. The research could lead to innovations in linking proteins to other materials for bioelectronic devices such as sensors that can diagnose disease or detect contaminants. Read more »
Footprinting Technique Gives ALS Users New Insights
The x-ray footprinting (XFP) technique developed at ALS Beamline 5.3.1 gives researchers a powerful tool for the study of macromolecular structures and dynamics of proteins and nucleic acids in solution. Read more »
Carotenoid Pigment Is the Key to Photoprotection
A technique newly available at the ALS has enabled the discovery of a surprising key event in photosynthetic systems. A protein shifting from an “orange” light-absorbing state to a “red” photoprotective state turns out to be an unanticipated molecular priming event in photoprotection. Read more »