CRYOCRYSTALLOGRAPHY OF INFLUENZA-VIRUS HEMAGGLUTININ CRYSTALS

X-ray diffraction data collected at cryogenic temperatures from flash-cooled crystals of influenza virus hemagglutinin show improvements in both resolution and quality relative to data collected at 277 K. These improvements are dramatic for flash-cooled hemagglutinin crystals irradiated with X-rays from a synchrotron source. At the Cornell High Energy Synchrotron Source hash-cooled hemagglutinin crystals diffracted at least 0.9 Angstrom farther than hemagglutinin crystals at ambient temperatures. Radiation damage in the flash-cooled crystals is reduced, making it possible to collect a complete data set from a single hemagglutinin crystal. However, radiation damage is not eliminated in the flash-cooled crystal. As a result the quality of X-ray data can be significantly degraded during long exposure times at a synchrotron source.