The highly automated macromolecular crystallography beamline AMX/17-ID-1 is an undulator-based high-intensity (>5 × 1012 photons s−1), micro-focus (7 µm × 5 µm), low-divergence (1 mrad × 0.35 mrad) energy-tunable (5–18 keV) beamline at the NSLS-II, Brookhaven National Laboratory, Upton, NY, USA. It is one of the three life science beamlines constructed by the NIH under the ABBIX project and it shares sector 17-ID with the FMX beamline, the frontier micro-focus macromolecular crystallography beamline. AMX saw first light in March 2016 and started general user operation in February 2017. At AMX, emphasis has been placed on high throughput, high capacity, and automation to enable data collection from the most challenging projects using an intense micro-focus beam. Here, the current state and capabilities of the beamline are reported, and the different macromolecular crystallography experiments that are routinely performed at AMX/17-ID-1 as well as some plans for the near future are presented.
A correction in the paper by Lazo et al. [(2021). J. Synchrotron Rad. 28, 1649–1661] is made.
Two new macromolecular crystallography (MX) beamlines at the National Synchrotron Light Source II, FMX and AMX, opened for general user operation in February 2017 [Schneider et al. (2013). J. Phys. Conf. Ser. 425, 012003; Fuchs et al. (2014). J. Phys. Conf. Ser. 493, 012021; Fuchs et al. (2016). AIP Conf. Proc. SRI2015, 1741, 030006]. FMX, the micro-focusing Frontier MX beamline in sector 17-ID-2 at NSLS-II, covers a 5-30 keV photon energy range and delivers a flux of 4.0 × 1012 photons s-1 at 1 Å into a 1 µm × 1.5 µm to 10 µm × 10 µm (V × H) variable focus, expected to reach 5 × 1012 photons s-1 at final storage-ring current. This flux density surpasses most MX beamlines by nearly two orders of magnitude. The high brightness and microbeam capability of FMX are focused on solving difficult crystallographic challenges. The beamline's flexible design supports a wide range of structure determination methods - serial crystallography on micrometre-sized crystals, raster optimization of diffraction from inhomogeneous crystals, high-resolution data collection from large-unit-cell crystals, room-temperature data collection for crystals that are difficult to freeze and for studying conformational dynamics, and fully automated data collection for sample-screening and ligand-binding studies. FMX's high dose rate reduces data collection times for applications like serial crystallography to minutes rather than hours. With associated sample lifetimes as short as a few milliseconds, new rapid sample-delivery methods have been implemented, such as an ultra-high-speed high-precision piezo scanner goniometer [Gao et al. (2018). J. Synchrotron Rad. 25, 1362-1370], new microcrystal-optimized micromesh well sample holders [Guo et al. (2018). IUCrJ, 5, 238-246] and highly viscous media injectors [Weierstall et al. (2014). Nat. Commun. 5, 3309]. The new beamline pushes the frontier of synchrotron crystallography and enables users to determine structures from difficult-to-crystallize targets like membrane proteins, using previously intractable crystals of a few micrometres in size, and to obtain quality structures from irregular larger crystals.
Here we present two robotic sample changers integrated into the experimental stations for the macromolecular crystallography (MX) beamlines AMX and FMX, and the biological small-angle scattering (bioSAXS) beamline LiX. They enable fully automated unattended data collection and remote access to the beamlines. The system designs incorporate high-throughput, versatility, highcapacity, resource sharing and robustness. All systems are centered around a sixaxis industrial robotic arm coupled with a force torque sensor and in-house end effectors (grippers). They have the same software architecture and the facility standard EPICS-based BEAST alarm system. The MX system is compatible with SPINE bases and Unipucks. It comprises a liquid nitrogen dewar holding 384 samples (24 Unipucks) and a stay-cold gripper, and utilizes machine vision software to track the sample during operations and to calculate the final mount position on the goniometer. The bioSAXS system has an in-house engineered sample storage unit that can hold up to 360 samples (20 sample holders) which keeps samples at a user-set temperature (277 K to 300 K). The MX systems were deployed in early 2017 and the bioSAXS system in early 2019.
Small angle X‐ray scattering is an important tool that reveals the behavior of proteins in their native environment. The scattering pattern produced from a SAXS experiment represents an average of all conformations present in the solution. Since most proteins in our body function in a solution environment, SAXS data can reveal additional biologically relevant states of a molecule or molecular complex. Furthermore, SAXS provides data about the shape and size of the molecule of interest and is a complementary technique to other structural methods. Combining SAXS data with X‐ray crystallography, NMR or Cryo‐EM can lead to a more robust understanding of the species being studied. High quality SAXS data can be used to build ab initio low resolution bead models, which provide a 3D envelope of your molecule. Here at the life sciences X‐ray scattering beamline (LiX), we collect data by flowing sample through the X‐ray path in a 3 channel flow cell. As the sample enters the X‐ray path, the simultaneous collection of SAXS and wide angle X‐ray scattering (WAXS) is obtained via a 3 detector setup. The detector setup has a q‐range of 0.006Å−1 to 3.2 Å−1, primarily to obtain scattering data from the water peak to normalize buffer subtraction. Automated sample handling at LiX allows for collection of up to 360 samples, packaging of data and processing. One challenge in obtaining high quality SAXS data is preparation of pure, monodisperse samples. For these complicated samples that have multiple species, our in‐line HPLC system seamlessly integrates with our beamline for SEC‐SAXS (size‐exclusion chromatography‐SAXS), and increases the chances of obtaining a more pure, monodisperse sample immediately before data collection.Support or Funding InformationLiX beamline is part of the Life Science Biomedical Technology Research resource, co‐funded by the National Institute of General Medical Sciences (NIGMS) under grant P41 GM111244 and by the DOE Office of Biological and Environmental Research under grant KP1605010, with additional support from NIH under grant S10 OD012331. The operation of NSLS2 is supported by US Department of Energy, Office of Basic Energy Sciences, under contract No. DE‐SC0012704.
Beamline X25 at the NSLS is one of the five beamlines dedicated to macromolecular crystallography operated by the Brookhaven National Laboratory Macromolecular Crystallography Research Resource group. This mini-gap insertion-device beamline has seen constant upgrades for the last seven years in order to achieve mini-beam capability down to 20 µm × 20 µm. All major components beginning with the radiation source, and continuing along the beamline and its experimental hutch, have changed to produce a state-of-the-art facility for the scientific community.
The research philosophy and new capabilities installed at NSLS beamline X26-C to support electronic absorption and Raman spectroscopies coupled with X-ray diffraction are reviewed. This beamline is dedicated full time to multidisciplinary studies with goals that include revealing the relationship between the electronic and atomic structures in macromolecules. The beamline instrumentation has been fully integrated such that optical absorption spectra and X-ray diffraction images are interlaced. Therefore, optical changes induced by X-ray exposure can be correlated with X-ray diffraction data collection. The installation of Raman spectroscopy into the beamline is also briefly reviewed. Data are now routinely generated almost simultaneously from three complementary types of experiments from the same sample. The beamline is available now to the NSLS general user population.
A high-flux insertion device and beamline for macromolecular crystallography has been built at the National Synchrotron Light Source (NSLS) that employs a mini-gap undulator source developed by the NSLS. The mini-gap undulator at beamline X29 is a hybrid-magnet device of period 12.5 mm operating at proven gaps of 3.3-10 mm. The beamline provides hard X-rays for macromolecular crystallography experiments from the second and third harmonics over an energy range of 5-15 keV. The X-ray optics is designed to deliver intense and highly collimated X-rays. Horizontal focusing is achieved by a cryogenically cooled sagittally focusing double-crystal monochromator with approximately 4.1:1 demagnification. A vertical focusing mirror downstream of the monochromator is used for harmonic rejection and vertical focusing. The experimental station hosts an Area Detector Systems Quantum 315 CCD detector with 2.2 s readout time between exposures and Crystal Logic goniostat for crystal rotation and detector positioning. An auto-mounter crystal changer has been installed to facilitate the high-throughput data collection required by the major users, which includes structural genomics projects and the Macromolecular Crystallography Research Resource mail-in program. X29 is 10(3) times brighter than any existing bending-magnet beamline at NSLS with an actual flux of 2.5 x 10(11) photons s(-1) through a 0.12 mm square aperture at 11.271 keV.
X-ray fluorescence spectroscopy is demonstrated here as a novel, element-specific detector for capillary electrophoresis. Monochromatic 10 keV X-rays from a synchrotron light source are used to excite core electrons, causing emission of characteristic Kalpha X-ray fluorescence (XRF) lines. Using this technique, XRF energies provide elemental identification, while XRF intensities can be used to quantitate the metal composition of each eluent. An X-ray transparent polymer coupling is used to create a window for the on-line, X-ray detection. This coupling contributes no measurable extra-column variance, and electrophoretic mobilities for the metal complexes used as model solutes are highly reproducible. The combination of XRF detection with capillary electrophoresis (CE-XRF) creates the first on-line detection system that is element-specific, nondestructive, and directly applicable to a broad range of applications including nonelectroactive species. CE-XRF is successfully demonstrated here for high binding-constant complexes of Fe(III), Co(II), Cu(II), and Zn(II). Within a single injection, electropherograms are obtained for each element of interest, with the element identity obtained directly from the emission energy. In contrast with ICPMS, this detection technique is directly on-line and does not require volatilization of the eluent. As a result, element-specific detection is not limited by the sample or the buffer volatility or atomization efficiency. Simultaneous XRF and UV absorbance detection can be used to provide an on-line determination of metal/chelate ratios. Although XRF detection limits are presently only in the 0.1 mM (0.5 ng) range, both collection geometry and incident intensity have yet to be optimized. Further optimization is expected to enhance this detection limit by another 2-3 orders of magnitude. As a result, the advent of XRF detection combined with the separating power of CE presents new possibilities for on-line, element-specific analysis.