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    • Keywords

       

      Synchrotron radiation; Laue diffraction; hen egg-white lysozyme; image plate; X-PLOR; electron density; amino acids

    • Abstract

       

      We have used lysozyme as a test case to illustrate the application of a new method of estimating the intensities of Laue multiples reflection data in protein crystallography. Hen egg-white lysozyme, an enzyme with a single polypeptide chain of 129 amino acids, crystallizes in space group P43212 with cell parametersa=b=79·1 Å,c=37·9 Å. Laue image plate data were collected using synchrotron radiation on station 9·5 at Daresbury with a total exposure time of 0·95 seconds. The data processed were separated into two data sets comprising the singles and the combined singles and deconvoluted multiples. The method of deconvolution was that of Campbell and Hao (1993), which utilizes the intensity variation of theλ-curve. Electron density maps (2FoFc) based on the two data sets are then compared. This comparison shows that the deconvoluted multiples do indeed contribute usefully to the continuity of the maps due to the improved completeness of the data. A number of map sections along the polypeptide chain, based on the two Laue data sets, are shown for comparison. These include Arg 5, His 15, Phe 38, Asp 52, Tyr 53, Pro 70, Trp 108 and the four disulphide bridges.

    • Author Affiliations

       

      John W Campbell1 Ashley Deacon2 Jarjis Habash2 John R Helliwell2 Sean McSweeney1 Hao Quan1 James Raftery2 Edward Snell2

      1. Daresbury Laboratory, SERC, Daresbury, Warrington - WA4 4AD, England
      2. Department of Chemistry, University of Manchester - Manchester M13 9PL, England
    • Dates

       
  • Bulletin of Materials Science | News

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