N. Sakabe

X-ray diffraction data collection system for modern protein crystallography with a Weissenberg camera and an imaging plate using synchrotron radiation

Abstract The X-ray diffraction data collection system, with a Weissenberg camera, an imaging plate, and image reader BA100, using SR was constructed in the Photon Factory for protein crystallography. It allows us to collect a full data set with one crystal in 2.5 h by rotation of a sample around a single axis. The high accuracy and extended resolution of the collected data were confirmed by comparison with the data obtained from other detectors and results from the structure determination. Further improvements in the function and accuracy of this system are discussed.

Weissenberg camera for macromolecules with imaging plate data collection system at the Photon Factory: Present status and future plan (invited)

A Weissenberg camera for macromolecules with imaging plate data collection system at BL6A and BL18B stations in the Photon Factory is introduced and evaluated. The special feature of these systems is considered matching for both SR‐x rays and protein crystallography. This system is user‐friendly and can collect a large amount of data to higher resolution from the crystal with large unit cell dimensions. A newly developed camera can be used as a time‐resolved Laue camera and a Weissenberg camera. A large image reader (IPR4080) that can scan 400×400 mm2 and 400×800 mm2 sizes of imaging plates has been developed and evaluated. The new data collection system combined with the new camera and IPR4080 will be installed at the BL18B station in October 1994.

Macromolecular crystallography station BL‐18B at the Photon Factory

A new experimental station, BL‐18B, has been constructed on a bending‐magnet beamline at the Photon Factory. The branch beamline is equipped with a Pt‐coated fused quartz bend cylindrical mirror of 1:1 focusing and a fixed‐exit double‐crystal monochromator. The mirror can focus an x‐ray beam to about 0.4 mm (vertical) ×1.2 mm (horizontal). The monochromator consists of two kinds of flat crystals, usually Si(111) and Ge(220), mounted side by side on the goniometer, and those two crystals can be interchanged without opening the vacuum chamber. In addition to increasing the experimental time available to users of the Weissenberg camera, BL‐18B provides a point focused white beam for the time‐resolved Laue method. In order to allow more effective exposures using Weissenberg and Laue methods, a new multipurpose camera using large imaging plates, 400 mm×400 mm and 400 mm×800 mm, is being developed. A special scanner for the large imaging plate has also been developed. Response of the scanner was tested and the ...

Diffraction structural biology - introductory overview

An introductory overview to the special issue papers on diffraction structural biology in this issue of the journal.

Rotated-inclined focusing monochromator with simultaneous tuning of asymmetry factor and radius of curvature over a wide wavelength range

A new single-crystal focusing monochromator for protein crystallography has been developed. In order to achieve simultaneous tuning of the beam demagnification rate and the radius of curvature for focusing over a wide wavelength range, the surface of an inclined monochromator was cylindrically bent. The monochromator is able to tune these two parameters simultaneously with a single rotation of the crystal about the azimuthal axis. A new monochromator incorporating this idea has been developed for beamline BL6B at the Photon Factory. The monochromator was designed for use in the wavelength range 0.87–1.90 A, and beam focusing was tested at wavelengths of 1.04, 1.38 and 1.74 A.

Highly bright X-ray generator using heat of fusion with a specially designed rotating anticathode.

A very compact X-ray generator, 4.3 times more brilliant than can be attained by a conventional rotating-anticathode X-ray generator, has been developed using a U-shaped rotating anticathode and a high-flux electron gun with focusing bending magnet.

Synchrotron radiation protein data collection system using the newly developed Weissenberg camera and imaging plate for crystal structure analysis (abstract)

It has been an earnest desire of protein crystallographers to collect fast, accurate, high resolution diffraction data from protein crystals, preferably with exposure time as short as possible. In order to meet this challenge, a new type of Weissenberg camera has been developed for the recording of diffraction intensity from protein crystals using synchrotron radiation. The BL6A2 line has a plane‐bending mirror designed by Y. Sato. The optical bench with triangular tilt‐cut Si crystal monochromator was designed by N. Kamiya and was installed in the BL6A2 hutch. The Weissenberg camera was set on the 2θ arm of the optical bench. This camera can be used with Fuji Imaging Plate (IP) as an x‐ray detector, and the reading out of the image from the IP is carried out by using BA100. The characterization of this system was carried out using the native crystal of chicken gizzard G‐actin DNase I complex and its Yb3+, PCMB, indium, and FMA derivatives. Since these crystals are very sensitive for x rays, the resolutio...

Time-Resolved Protein Crystallography with Large-Angle Oscillations: an Application of a Protein Data-Collection System Using the Weissenberg Technique and a Large-Format Imaging Plate

A diffraction-intensity data-collection system with synchrotron radiation X-rays utilizing the screenless Weissenberg technique and incorporating a large-format imaging plate is one of the most suitable apparatus for time-resolved protein crystallography with larger angle oscillations than hitherto described. The time resolution and data quality of the system have been tested using a tetragonal lysozyme crystal as a test sample in a flow-cell experiment at the bending-magnet beamline 18B at the Photon Factory, and a time resolution of 15 min is confirmed.

U-shape rotating anti-cathode compact X-ray generator: 20 times stronger than the commercially available X-ray source

A new type of U-shape anti-cathode X-ray generator in which the inner surface of a cylindrical target is irradiated by an electron beam has been made by modifying a conventional rotating anti-cathode X-ray generator whose brightness in the catalog is 12 kW mm−2. A brightness of 129 kW mm−2 was thereby obtained with this new U-shape-type X-ray generator. This new X-ray generator is expected to be of keen interest for applications in academia, industry and in hospitals.

Research and development of an electron beam focusing system for a high-brightness X-ray generator

In order to minimize the size of the X-ray source for a U-shaped rotating anticathode X-ray generator, the electron beam is focused over a short distance by a combined-function bending magnet. Simulation predicts that the beam brightness will reach almost 500 kW mm−2 for a 120 keV/75 mA beam.