High-resolution crystallographic studies of native concanavalin A using rapid Laue data collection methods and the introduction of a monochromatic large-angle oscillation technique (LOT)

Weisgerber, S.; Helliwell, John R.

doi:10.1039/ft9938902667

Cited by 35 publications

(27 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The analytical profile fitting has been demonstrated to be very suitable for such difficult spot deconvolution. This profile-fitting technique can obviously be extended to handle any two-dimensional spot integration in macromolecular crystallography, such as large-angle oscillation images (Weisgerber & Helliwell, 1993), where spatial overlap between adjacent spots could be severe or spot shapes could be far from standard.…”

Section: Discussionmentioning

confidence: 99%

Quantitative Analysis of Time-Resolved Laue Diffraction Patterns

Ren¹,

Ng²,

Borgstahl³

et al. 1996

J Appl Cryst

View full text Add to dashboard Cite

Integration and quantification of time-resolved Laue images poses problems beyond those encountered with static Laue images. The flexible analytical profile-fitting technique [Ren & Moffat (1995). J.. AppL Cryst. 28, has been extended to handle the integration of multiple-spot images with two or more exposures at different time points superimposed on a single detector flame but displaced by a small shift. Each Lane pattern on a multiple-spot image can be integrated separately; possible spatial overlaps between adjacent spots from either the same or different exposures can be resolved; streakiness and streakiness anisotropy are allowed to be different for each time point. Various strategies for timeresolved Lane diffraction data collection and processing are compared. Time-resolved Lane images obtained during the relaxation of photoactive yellow protein (PYP) from its photostationary state have been processed by the Laue data reduction package LaueView. Continuous laser illumination of PYP crystals establishes a photostationary state and termination of laser illumination starts a relaxation process. However, PYP crystals at the photostationary state are more anisotropically mosaic than those at the ground state, and the mosaicity and its anisotropy vary during the relaxation. Accurate integration of elongated and spatially overlapping spots therefore becomes more difficult. Two data processing strategies have been applied to calculate time-dependent difference Fourier maps of PYP. The first route takes advantage of both the wavelength normalization and the harmonic deconvolution [Ren & Moffat (I 995). J. AppL Cryst. 28,[482][483][484][485][486][487][488][489][490][491][492][493] algorithms. The second is the method of relative percentage changes of structurefactor amplitudes.

show abstract

Section: Discussionmentioning

confidence: 99%

Quantitative Analysis of Time-Resolved Laue Diffraction Patterns

Ren¹,

Ng²,

Borgstahl³

et al. 1996

J Appl Cryst

View full text Add to dashboard Cite

show abstract

“…The Laue approach, in the narrow bandpass exposition, has more recently become relevant for neutron protein data collection at the Institut Laue Langevin with its Laue diffractometer ('LADI'); see Fig. 2. (ii) Large-angle oscillation technique (LOT) diffraction patterns (Weisgerber & Helliwell, 1993);see Figs. 3(a) and 3(b).…”

Section: Experiments Where Good Crystal Perfection Has Been Identifiementioning

confidence: 99%

“…A colour version of this figure is available in the online edition of the journal. Another example of a congested spot pattern, the case of the large-angle oscillation technique (LOT) diffraction (from Weisgerber & Helliwell, 1993. Reproduced with permission of the Royal Society of Chemistry.).…”

Section: Assessing Protein Crystal Perfectionmentioning

confidence: 99%

“…(a) The principle behind LOT; the rotation of the crystal beyond the typical d min /maximum unit-cell dimension is not in fact limiting as the Bragg angles of these two reciprocal lattice points (h, k, l and h + 1, k, l) are slightly different. (b) LOT practice; a 90 rotation X-ray diffraction photograph recorded at SRS station 9.5, wavelength $1 Å from concanavalin A saccharide-free crystal form space group I222, unit-cell dimensions a = 88, b = 86, c = 62 Å , diffraction resolution at the edge is 5 Å (higher resolution, d min = 3 Å , randomly set crystal diffraction pattern examples are also given in Weisgerber & Helliwell, 1993). mosaicity was investigated (Helliwell, 1988;Colapietro et al, 1992) as a direct indicator of the physical perfection of the macromolecular crystal.…”

Section: Assessing Protein Crystal Perfectionmentioning

confidence: 99%

See 1 more Smart Citation

Protein crystal perfection and its application

Helliwell

2005

Acta Crystallogr D Biol Cryst

Self Cite

View full text Add to dashboard Cite

Knowledge of protein crystal perfection in theory and practice is reviewed. X-ray methods of assessing perfection such as mosaicity, topography and reciprocal-space mapping are described. X-ray diffraction physics applications of protein crystals such as in Laue geometry, the large-angle oscillation technique and forming polychromatic profiles across diffraction spots are covered. Cryo-and room-temperature cases are discussed including in X-ray and neutron protein crystallography. Experience of freezing very large crystals, which are commonly used today in neutron protein crystallography, is highlighted.

show abstract

“…Weisgerber & Helliwell (1993) suggested a new large-angle oscillation technique (LOT) as a supplement to the Laue method in order to completely retrieve the low-resolution data. In our opinion, LOT is a promising monochromatic technique, but spatial overlap is a serious problem due to the huge oscillation angle.…”

Section: Large-angle Oscillation and Weissenberg Imagesmentioning

confidence: 99%

Quantitative Analysis of Synchrotron Laue Diffraction Patterns in Macromolecular Crystallography

Ren¹,

Moffat²

1995

J Appl Crystallogr

View full text Add to dashboard Cite

The reduction of X-ray diffraction data obtained by the Laue method to accurate integrated intensities is more complicated and much less familiar than the reduction of monochromatic data. Problems of data accuracy and completeness have hindered the wide use of the Laue technique in macromolecular crystallography. Its unique advantage, data-collection speed, has been exploited only in situations such as fast time-resolved crystallography, to which monochromatic techniques are not as well suited. This paper reviews the major problems in data reduction in the Laue technique and provides a unified solution to the problems in integration of both streaky and spatially overlapping spots and data scaling. This solution has been incorporated into a new Laue diffraction datareduction software package, LaueView. Laue data sets from crystals of lysozyme and ~-haemolysin have been processed to test this solution, and demonstrate that Laue data sets can be reduced to yield structure amplitudes of at the very least the same quality as the best monochromatic data sets in terms of both accuracy and completeness.

show abstract

High-resolution crystallographic studies of native concanavalin A using rapid Laue data collection methods and the introduction of a monochromatic large-angle oscillation technique (LOT)

Cited by 35 publications

References 11 publications

Quantitative Analysis of Time-Resolved Laue Diffraction Patterns

Quantitative Analysis of Time-Resolved Laue Diffraction Patterns

Protein crystal perfection and its application

Quantitative Analysis of Synchrotron Laue Diffraction Patterns in Macromolecular Crystallography

Contact Info

Product

Resources

About