Successful protein cryocooling for powder diffraction

2007 ◽  
Vol 40 (1) ◽  
pp. 121-124 ◽  
Author(s):  
Mark J. Jenner ◽  
Jonathan P. Wright ◽  
Irene Margiolaki ◽  
Andrew N. Fitch

It is shown that samples of microcrystalline tetragonal chicken egg white lysozyme can be effectively cryoprotected for high-resolution synchrotron X-ray powder diffraction studies at 100 K. The survival of the powder in the beam is increased by a factor of around 30. Thus, a high-quality powder diffraction pattern could be collected at 100 K, which attains a resolution ofdmin≃ 2.6 Å, significantly better than the previous limit of ∼3.27 Å at room temperature, despite a smaller volume of sample. Systematic variations of the concentration and type of cryoprotectant agent show that the lattice microstrains that accompany cooling, and degrade the quality of the powder diffraction data by broadening the diffraction peaks, are caused by a collapse in the volume of the crystalline unit cell.

1990 ◽  
Vol 5 (3) ◽  
pp. 137-143 ◽  
Author(s):  
R.I. Smith ◽  
A.R. West ◽  
I. Abrahams ◽  
P.G. Bruce

AbstractThe crystal structure of metastable Li2Si2O5, Fw = 150.05, has been refined by the Rietveld method using high resolution X-ray powder diffraction data recorded at the Daresbury Synchrotron Radiation Source on the new 8.3 diffractometer. Li2Si2O5, in keeping with many compounds of interest to the materials scientist, exhibits relatively broad diffraction peaks. It is important to establish the quality of crystal structure data that may be obtained from such materials on this new instrument. Various functions were used to model the peak shape from this instrument; a split-Pearson VII function appeared to be marginally superior to Pearson VII or Pseudo-Voigt functions. Refinement was carried out using the split-Pearson VII in the space group Pbcn (60) and terminated with a = 5.6871(6), b = 4.7846(5), c = 14.645(1) Å, V = 398.50 Å3, Z=4, Dc= 2.502 gcm−3, Rwp = 17.06, Rex = 14.48 and Χ2 = 1.39. The refined parameters are compared with those obtained from a previous single crystal X-ray determination.


2001 ◽  
Vol 16 (1) ◽  
pp. 37-41 ◽  
Author(s):  
E. Smit ◽  
B. Manoun ◽  
S. M. C. Verryn ◽  
D. de Waal

The effects of proper drying and grinding of [Fe(Htrz)3](ClO4)2⋅1.85H2O specimens on the quality of X-ray powder patterns are illustrated (Htrz=1H-1,2,4-Triazole). A procedure is suggested to achieve high-quality, reproducible X-ray powder patterns of the compound. The observed powder diffraction data of the compound are reported together with preliminary indices calculated for a monoclinic system with cell parameters a=15.8160 Å, b=20.6134 Å, c=13.0321 Å, β=103.83° and Volume=4125.633 Å3, with reliability factors: M15=10.4, F15=22.0 (0.0100; 68) and space group P21/m. This compound is very similar to the compound [Cu(Hyetrz)3](ClO4)2⋅3H2O and a comparison is made between the cell parameters of the two compounds


2021 ◽  
pp. 1-3
Author(s):  
Carina Schlesinger ◽  
Edith Alig ◽  
Martin U. Schmidt

The structure of the anticancer drug carmustine (1,3-bis(2-chloroethyl)-1-nitrosourea, C5H9Cl2N3O2) was successfully determined from laboratory X-ray powder diffraction data recorded at 278 K and at 153 K. Carmustine crystallizes in the orthorhombic space group P212121 with Z = 4. The lattice parameters are a = 19.6935(2) Å, b = 9.8338(14) Å, c = 4.63542(6) Å, V = 897.71(2) ų at 153 K, and a = 19.8522(2) Å, b = 9.8843(15) Å, c = 4.69793(6) Å, V = 921.85(2) ų at 278 K. The Rietveld fits are very good, with low R-values and smooth difference curves of calculated and experimental powder data. The molecules form a one-dimensional hydrogen bond pattern. At room temperature, the investigated commercial sample of carmustine was amorphous.


Author(s):  
Robert E. Dinnebier ◽  
Hanne Nuss ◽  
Martin Jansen

AbstractThe crystal structures of solvent-free lithium, sodium, rubidium, and cesium squarates have been determined from high resolution synchrotron and X-ray laboratory powder patterns. Crystallographic data at room temperature of Li


1998 ◽  
Vol 537 ◽  
Author(s):  
M. Suscavage ◽  
M. Harris ◽  
D. Bliss ◽  
P. Yip ◽  
S.-Q. Wang ◽  
...  

AbstractZinc Oxide crystals have historically been grown in hydrothermal autoclaves with a basic mineralizer; however, doubts have been raised about the quality of such crystals because they have often exhibited large x-ray rocking curve widths and low photoluminescence (PL) yield with large linewidths. Several ZnO crystals were grown hydrothermally and sliced parallel to the c-plane. This resulted in opposite surfaces (the C+ and C-) exhibiting pronounced chemical and mechanical differences. Different surface treatments were investigated and compared by PL both at room temperature and liquid helium temperatures, and by double axis X-ray rocking curve measurements. The high quality of hydrothermally-grown ZnO is substantiated by the narrow rocking curve widths and sharp PL peaks obtained. A critical factor in obtaining these results was found to be surface preparation.


1997 ◽  
Vol 12 (3) ◽  
pp. 134-135
Author(s):  
Liangqin Nong ◽  
Lingmin Zeng ◽  
Jianmin Hao

The compound DyNiSn has been studied by X-ray powder diffraction. The X-ray diffraction patterns for this compound at room temperature are reported. DyNiSn is orthorhombic with lattice parameters a=7.1018(1) Å, b=7.6599(2) Å, c=4.4461(2) Å, space group Pna21 and 4 formula units of DyNiSn in unit cell. The Smith and Snyder Figure-of-Merit F30 for this powder pattern is 26.7(0.0178,63).


2005 ◽  
Vol 20 (1) ◽  
pp. 18-21 ◽  
Author(s):  
W. X. Yuan ◽  
J. W. Hu ◽  
Y. T. Song ◽  
W. J. Wang ◽  
Y. P. Xu

The ternary nitridotungstate Li6WN4 has been synthesized via the solid state reaction of lithium subnitride, Li3N, with W under nitrogen. High quality X-ray powder diffraction data were collected for the crystal-structure determination. Li6WN4 crystallizes in the tetragonal system, space group P42∕nmc, with cell parameters a=6.6759(3) Å and c=4.9280(3) Å, Z=2. Preliminary thermal stability measurements of Li6WN4 show that it is sensitive to moisture, even at room temperature, and decomposes at high temperatures below 1000 °C under flowing nitrogen.


2008 ◽  
Vol 23 (3) ◽  
pp. 259-264 ◽  
Author(s):  
Mark A. Rodriguez ◽  
Robert M. Ferrizz ◽  
Clark S. Snow ◽  
James F. Browning

X-ray powder diffraction data for ErH2−xDx formed by hydrogen (i.e., protium)–deuterium loading of Er metal are reported. Lattice parameters for the varying hydrogen–deuterium compositions followed Vergard’s law behavior. The cubic lattice parameter at room temperature for ErH2−xDx obeys a linear relationship according to the formula a=5.1287−1.1120×10−4⋅x, where a is the lattice parameter of the fluorite-type structure and x is the mole percent of deuterium. Microstrain measurements suggest a possible ordering of hydrogen and deuterium in the composition ErH1D1.


1999 ◽  
Vol 14 (4) ◽  
pp. 280-283 ◽  
Author(s):  
A. Rafalska-Łasocha ◽  
W. Łasocha ◽  
M. Michalec

The X-ray powder diffraction patterns of anilinium trimolybdate tetrahydrate, (C6H5NH3)2Mo3O10·4H2O, and anilinium trimolybdate dihyhydrate, (C6H5NH3)2Mo3O10·2H2O, have been measured in room temperature. The unit cell parameters were refined to a=11.0670(7) Å, b=7.6116(8) Å, c=25.554(3) Å, space group Pnma(62) and a=17.560(2) Å, b=7.5621(6) Å, c=16.284(2) Å, β=108.54(1)°, space group P21(4) or P21/m(11) for orthorhombic anilinium trimolybdate tetrahydrate and monoclinic anilinium trimolybdate dihydrate, respectively.


2009 ◽  
Vol 24 (3) ◽  
pp. 250-253 ◽  
Author(s):  
Peter Varlashkin

The room temperature powder pattern of lapatinib ditosylate monohydrate (active ingredient in Tykerb used to treat refractory breast cancer) was indexed and the cell from the single crystal X-ray diffraction structure was refined using the experimental capillary data. Unit-cell parameters for the orthorhombic compound with space group Pbca refined from powder diffraction data are a=9.6850±0.0009 Å, b=29.364±0.003 Å, and c=30.733±0.003 Å, α=β=γ=90°, z=8, V=8740.1 Å3. Values of 2θ, d, I, and Miller indices are reported.


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