Download citation
Acta Cryst. (2014). A70, C110
Download citation

link to html
Small Angle X-ray Scattering (SAXS) experiments of macromolecules (proteins, nucleic acids, ...) in solution can provide a wealth of information concerning structure, dynamics and therefore function. However, correct interpretation of results depends critically on data quality. To achieve this, well defined acquisition protocols and immediate feedback are essential. At beamline BM29 at ESRF, BioSAXS data are acquired in a temperature controlled flow through capillary. Samples and buffers can be loaded into the capillary via a robotic liquid handling sample changer (SC) [1] or by connecting the capillary to the outlet of a size exclusion chromatography (SEC) setup [2]. Samples loaded by the SC can be passed through the beam to avoid unwanted effects caused by radiation damage. All recorded data are immediately analyzed to give user-oriented feedback on estimated molecular weight, size, possible radiation damage and inter-particle effects, quality of background correction, etc. Subsequent downstream analysis, also carried out autmatically, results in the calculation of molecular envelopes for solution structures. The information management system ISPyBB (Information System for Protein crystallography Beamlines and BioSAXS) logs and presents all information on data acquisition and analysis and allows users to easily compare the results of different data acquisitions and to decide whether further measurements or changes of acquisition parameters are necessary. The combination of these tools allows non-expert users to carry out BioSAXS experiments autonomously, thereby making the technique accessible to a broader community.

Download citation
Acta Cryst. (2014). A70, C1733
Download citation

link to html
We present the final design of the x-ray optical systems and experimental stations of the two macromolecular crystallography (MX) beamlines, FMX and AMX, at the National Synchrotron Light Source-II (NSLS-II). Along with its companion x-ray scattering beamline, LIX, this suite of Advanced Beamlines for Biological Investigations with X-rays (ABBIX, [1]) will begin user operation in 2016. The pair of MX beamlines with complementary and overlapping capabilities is located at canted undulators (IVU21) in sector 17-ID. The Frontier Microfocusing Macromolecular Crystallography beamline (FMX) will deliver a photon flux of ~5x10^12 ph/s at a wavelength of 1 Å into a spot of 1 - 50 µm size. It will cover a broad energy range from 5 - 30 keV, corresponding to wavelengths from 0.4 - 2.5 Å. The highly Automated Macromolecular Crystallography beamline (AMX) will be optimized for high throughput applications, with beam sizes from 4 - 100 µm, an energy range of 5 - 18 keV (0.7 - 2.5 Å), and a flux at 1 Å of ~10^13 ph/s. Central components of the in-house-developed experimental stations are a 100 nm sphere of confusion goniometer with a horizontal axis, piezo-slits to provide dynamic beam size changes during diffraction experiments, a dedicated secondary goniometer for crystallization plates, and sample- and plate-changing robots. FMX and AMX will support a broad range of biomedical structure determination methods from serial crystallography on micron-sized crystals, to structure determination of complexes in large unit cells, to rapid sample screening and data collection of crystals in trays, for instance to characterize membrane protein crystals and to conduct ligand-binding studies. Together with the solution scattering program at LIX, the new beamlines will offer unique opportunities for advanced diffraction experiments with micro- and mini-beams, with next generation hybrid pixel array detectors and emerging crystal delivery methods such as acoustic droplet ejection. This work is supported by the US National Institutes of Health.
Follow Acta Cryst. A
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds