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Notes: 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. © 1995 American Institute of Physics.

Notes: 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 resolution limit of the diffraction was 5 A(ring) with a 4-circle diffractometer on a rotating anode x-ray generator (N. Sakabe et al., J. Biochem. 95, 887. This complex was crystallized in space group P2,2,2, with a=42.0, b=225.3, and c=77.4 A(ring). The data were collected with this system with the 430-mm radius cassette when Photon Factory was operated at 2.5 GeV and 270 mA and the wavelength λ=1.004 A(ring) was chosen. In order to avoid overlapping of diffraction spots, oscillation angle range and coupling constant (degree/mm) were settled on the basis of simulation patterns of diffraction spots up to the maximum resolution to be measured considering the direction of the crystal axes, wavelength, radius of the camera, and mosaicness of the crystal. When the oscillation axis was a axis, the oscillation angle range was selected at either 10° (1°/mm) or 5° (0.5°/mm) depending on the density of reciprocal lattice points along the incident beam, and typical exposure time in each IP was 50 and 25 s, respectively. The exposure was stopped after 10 times oscillation. The total range of 117.5° was recorded on 16 sheets of IP with an overlapping range 0.5°.The data processing was carried out using program weis coded by T. Higashi. Two complete data sets along the a and c axes were collected using two crystals, independently, and the merge R(F2) for native crystal was 0.068. In order to know the feasibility of the data (F+−F−), Patterson maps were calculated with data of each derivative, and heavy atom vectors clearly appeared as prominent peaks in the Harker sections of the Patterson maps of both Yb3+ and PCMB derivatives. The heavy atom positions were obtained from the combinations of different Patterson and different Fourier maps, and were refined by using least-squares techniques. The final figure of merit up to 2.5 A(ring) resolution was 0.61 with 22 700 reflections. The assignment of DNase I part on the electron density maps is progressing using the Nicholson molecular model referring to its structure reported by C. Oefner and D. Suck [J. Mol. Biol. 192, 605 (1986)]. In addition to promising results of ω-aminoacid pyruvate aminotransferase [N. Watanabe et al., Book of abstracts of second Japan-China Bilateral Symposium on Biophysics, p. 83 (1988)], these results support that this data collection system consisting of a new type of Weissenberg camera using SR, Fuji Imaging Plate, BA100, and program weis is one of the fastest and most accurate systems for protein crystallography in use today. We thank the Education Ministry and the Foundations of Yamada, Naito and Toray for the financial support of this project. We are grateful to Dr. K. Namba of ERATO for our use of BA100.

Notes: A conventional Weissenberg camera [Weissenberg (1924). Z. Phys. 23, 229–238] has been modified for macromolecular crystallography. This camera system consists of a doubly bent LiF monochromator, a newly designed Weissenberg goniometer with multi-layer-line screens and its controller. The camera is useful for recording many reflections up to high resolution on a film with high signal-to-background ratio from a crystal with large unit-cell dimensions without losing any of the diffracted beams by screens. The resulting photograph is very easy to index, and the ratio of partially recorded reflections to fully recorded reflections decreases in comparison with an oscillation camera. The multi-layer-line screens are especially practical with a continuous X-ray beam such as synchrotron radiation where both wavelength and band pass can be selected properly. The preparation of a point-focusing monochromator from a single-crystal of LiF is described, and the recording of anomalous dispersion profiles is discussed.

Notes: 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.

Notes: Off-line and on-line protein data-collection systems using an imaging plate as a detector are described and their components reported. The off-line scanner IPR4080 was developed for a large-format imaging plate `BASIII' of dimensions 400 × 400 mm and 400 × 800 mm. The characteristics of this scanner are a dynamic range of 105 photons pixel−1, low background noise and high sensitivity. A means of reducing electronic noise and a method for finding the origin of the noise are discussed in detail. A dedicated screenless Weissenberg camera matching IPR4080 with synchrotron radiation was developed and installed on beamline BL6B at the Photon Factory. This camera can attach one or two sheets of 400 × 800 mm large-format imaging plate inside the film cassette by evacuation. The positional reproducibility of the imaging plate on the cassette is so good that the data can be processed by batch job. Data of 93% completeness up to 1.6 Å resolution were collected on a single axis rotation and the value of Rmerge becomes 4% from a tetragonal lysozyme crystal using a set of two imaging-plate sheets. Comparing two types of imaging plates, the signal-to-noise ratio of the ST-VIP-type imaging plate is 25% better than that of the BASIII-type imaging plate for protein data collection using 1.0 and 0.7 Å X-rays. A new on-line protein data-collection system with imaging plates is specially designed to use synchrotron radiation X-rays at maximum efficiency.

Notes: This paper reports an empirical method for evaluating the three-dimensional transmission by the statistical treatment of the intensity differences among equivalent reflexions, and the accuracy of the method is discussed.