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X-ray Diffraction Data Collection (x-ray + diffraction_data_collection)
Selected AbstractsThe plug-based nanovolume Microcapillary Protein Crystallization System (MPCS)ACTA CRYSTALLOGRAPHICA SECTION D, Issue 11 2008Cory J. Gerdts The Microcapillary Protein Crystallization System (MPCS) embodies a new semi-automated plug-based crystallization technology which enables nanolitre-volume screening of crystallization conditions in a plasticware format that allows crystals to be easily removed for traditional cryoprotection and X-ray diffraction data collection. Protein crystals grown in these plastic devices can be directly subjected to in situ X-ray diffraction studies. The MPCS integrates the formulation of crystallization cocktails with the preparation of the crystallization experiments. Within microfluidic Teflon tubing or the microfluidic circuitry of a plastic CrystalCard, ,10,20,nl volume droplets are generated, each representing a microbatch-style crystallization experiment with a different chemical composition. The entire protein sample is utilized in crystallization experiments. Sparse-matrix screening and chemical gradient screening can be combined in one comprehensive `hybrid' crystallization trial. The technology lends itself well to optimization by high-granularity gradient screening using optimization reagents such as precipitation agents, ligands or cryoprotectants. [source] Crystallization in the presence of glycerol displaces water molecules in the structure of thaumatinACTA CRYSTALLOGRAPHICA SECTION D, Issue 12 2002Christophe Charron The intensely sweet protein thaumatin has been crystallized at 293,K in the presence of sodium tartrate and 25%(v/v) glycerol for X-ray diffraction data collection at 100,K. A comparison of the three-dimensional structure model derived from a crystal grown in the presence of glycerol with that of a control deprived of this additive reveals only minor changes in the overall structure but a ,20% reduction in the number of water molecules. X-ray topography analyses show that the overall quality of the crystals prepared in the presence of this cryoprotectant is enhanced. [source] Crystallization and preliminary crystallographic analysis of the Clostridium perfringens enterotoxinACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 7 2010David C. Briggs Clostridium perfringens is a Gram-positive anaerobic species of bacterium that is notable for its ability to produce a plethora of toxins, including membrane-active toxins (,-toxins), pore-forming toxins (,-toxins) and binary toxins (,-toxins). Here, the crystallization of the full-length wild-type C. perfringens enterotoxin is reported, which is the causative agent of the second most prevalent food-borne illness in the United States and has been implicated in many other gastrointestinal pathologies. Several crystal forms were obtained. However, only two of these optimized crystal forms (I and II) were useable for X-ray diffraction data collection. The form I crystals diffracted to dmin = 2.7,Å and belonged to space group C2, while the form II crystals diffracted to dmin = 4,Å and belonged to space group P213. [source] Crystallization and preliminary X-ray diffraction analysis of crotoxin B from Crotalus durissus collilineatus venomACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 10 2009G. H. M. Salvador Crotoxin B is a basic phospholipase A2 found in the venom of several Crotalus durissus ssp. rattlesnakes and is one of the subunits that constitute crotoxin, the main component of the venom of these snakes. This heterodimeric toxin is related to important envenomation effects such as neurological disorders, myotoxicity and renal failure. Although crotoxin was first crystallized in 1938, the first structural data only became available in 2007 (for crotoxin B from C. durissus terrificus) and showed an ambiguous result for the biological assembly, which could be either dimeric or tetrameric. In this work, the crystallization, X-ray diffraction data collection at 2.2,Å resolution and molecular-replacement solution of a dimeric complex formed by two crotoxin B isoforms from C. durissus collilineatus venom is presented. [source] Crystallization and X-ray diffraction data collection of topoisomerase IV ParE subunit from Xanthomonas oryzae pv. oryzaeACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 6 2009Hye Jeong Shin Topoisomerase IV is involved in topological changes in the bacterial genome using the free energy from ATP hydrolysis. Its functions are the decatenation of daughter chromosomes following replication by DNA relaxation and double-strand DNA breakage. In this study, the N-terminal fragment of the topoisomerase IV ParE subunit from Xanthomonas oryzae pv. oryzae was overexpressed in Escherichia coli, purified and crystallized. Diffraction data were collected to 2.15,Å resolution using a synchrotron-radiation source. The crystal belonged to space group P42212, with unit-cell parameters a = b = 105.30, c = 133.76,Å. The asymmetric unit contains one molecule, with a corresponding VM of 4.21,Å3,Da,1 and a solvent content of 69.6%. [source] | ||||||||||