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Form II (form + ii)
Kinds of Form II Terms modified by Form II Selected AbstractsPolymorph transitions of bicalutamide: A remarkable example of mechanical activationJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 8 2008Zoltán Német Abstract Bicalutamide, an active pharmaceutical ingredient possessing antiandrogenic activity, is known to exhibit polymorphism. The higher melting Form I relates monotropically to the lower melting Form II. The amorphous form can be easily produced by quench cooling the melt, but it is known to crystallize spontaneously to Form II at room temperature within days. Our results show that crystallization of amorphous bicalutamide is greatly influenced by experimental conditions and sample treatment. The effect of mechanical activation on the polymorph transitions is investigated in detail. Seeds of Form I can be formed in the amorphous phase even due to gentle mechanical treatment, which results in crystallization to the more stable structure at elevated temperature. The crystalline Form II may as well be transformed to the stable modification through mechanical activation at elevated temperature. © 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97: 3222,3232, 2008 [source] Energetic aspects of diclofenac acid in crystal modifications and in solutions,mechanism of solvation, partitioning and distributionJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 5 2007German L. Perlovich Abstract Temperature dependency of saturated vapor pressure and heat capacity for the diclofenac acid (Form II) were measured and thermodynamic functions of sublimation calculated (,,=,49.3 kJ,·,mol,1; ,,=,115.6,±,1.3 kJ,·,mol,1; ,,=,222,±,4 J,·,mol,1,·,K,1). Crystal polymorphic Forms I (P21/c) and II (C2/c) of diclofenac acid have been prepared and characterized by X-ray diffraction experiments. The difference between crystal lattice energies of the two forms were obtained by solution calorimetry: ,,Hsol(I,,,II),=,1.6,±,0.4 kJ,·,mol,1. Temperature dependencies of the solubility in buffers with pH 2.0 and 7.4, n-octanol and n-hexane were measured. The thermodynamic functions of solubility, solvation, and transfer processes were deduced. Specific and non-specific solvation terms were distinguished using the transfer from the "inert" n-hexane to the other solvents. The transfer of diclofenac acid molecules from the buffers to n-octanol (partitioning and distribution) is an entropy driven process. © 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 96: 1031,1042, 2007 [source] A study of sulfamerazine single crystals using atomic force microscopy, transmission light microscopy, and Raman spectroscopyJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 9 2005Xiaoping Cao Abstract Sulfamerazine (SMZ) Form I and II single crystals were prepared from aqueous dispersions of SMZ bulk samples and studied using several microscopic and spectroscopic techniques. Transmission light microscopy and Raman spectroscopy were used to observe and identify single crystals. The results indicated that Form I single crystals tended to be rectangular laths while Form II ones tended to be hexagonal laths. Surface morphology of individual single crystals was further investigated by atomic force microscopy (AFM). AFM images revealed a smooth top surface, a uniform height, and sharp edges for both forms of single crystals. Both height and phase images showed crystalline terraces with different step heights for the top surface of Form I. Surface properties of single crystals were evaluated using AFM force measurements. Experimental results indicated that the top surface of Form I single crystals was more hydrophilic than that of Form II. Theoretical calculations predicted a dominant crystal face of (020) for the Form I single crystals and (002) for the Form II ones. The correlations between calculation predictions and experimental results were discussed. © 2005 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 94:1881,1892, 2005 [source] Surface characterization of salmeterol xinafoate powders by inverse gas chromatography at finite coverageJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 3 2005Henry H.Y. Tong Abstract In our previous studies, surface analysis by inverse gas chromatography (IGC) at infinite dilution (zero coverage) was performed on four salmeterol xinafoate (SX) powdered samples, viz, two supercritical CO2 -processed Form I (SX-I) and Form II (SX-II) polymorphs, a commercial granulated SX (GSX) raw material and its micronized product (MSX). Both GSX and MSX are also of the same Form I polymorph. To further probe the differences in surface properties between the samples, the present study has extended the IGC analysis to the finite concentration range of selected energy probes. The adsorption isotherms of the SX samples were constructed using (nonpolar) octane, (polar acidic) chloroform, and (polar basic) tetrahydrofuran as liquid probes. Type II adsorption isotherms with weak knees were observed with each probe for all SX Form I samples. The extents of probe adsorption by the samples at various relative pressures follow the rank order: SX-II,>,GSX,,,MSX,>,SX-I, indicating that the SX-I has fewer high-energy adsorption sites than GSX and MSX. Type III isotherms were observed for SX-II with the two polar probes, indicative of weak adsorbate,adsorbent interactions. The additional information generated shows that IGC analysis at finite coverage is a valuable complementary tool to that at infinite dilution. © 2005 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 94:695,700, 2005 [source] Crystal-crystal transformations in isotactic polybutene-1 oriented filaments and in thick molded rodsPOLYMER ENGINEERING & SCIENCE, Issue 6 2001Cheol-Ho Choi This paper reports two related studies of the Form II , Form I crystal-crystal transformation in isotactic polybutene-1. First, it was found that in melt spun filaments, the rate of transformation is higher in filaments possessing higher levels of crystalline orientation. Second, we consider the occurrence of this phase transformation in thick quenched cylindrical rods. It was found that the phase transformation occurs more rapidly in the core than at the surface of the part. It is hypothesized that the mechanism of the higher transformation rate in the core is due to the development of residual quench stresses associated with densification at solidification. These stress levels have been calculated and our results compared with earlier studies. [source] Form II of monoclinic methyl ,-carboline-3-carboxylateACTA CRYSTALLOGRAPHICA SECTION C, Issue 6 2001Maciej Kubicki The crystal structure of the second monoclinic P21/c form of the ,-carboline-3-carboxylate, C13H10N2O2, has been determined. Very small changes in the packing scheme lead to a different unit cell; the role of weak C,H,O hydrogen bonds seems to be crucial. [source] Supercritical CO2 induced phase transition of Form III in isotactic poly-1-buteneASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 5 2009Lei Li Abstract The effect of supercritical or high-pressure CO2 on the recrystallization of Form II in isotactic poly-1-butene (iPB-1) during the melting of Form III was investigated using high-pressure differential scanning calorimetry (DSC). The results showed that the recrystallization of Form II was inhibited by CO2. The crystal,crystal transition of Form III to I, in ambient nitrogen and supercritical CO2 was studied using fourier transform infrared spectroscopy (FTIR) and DSC. The results showed that CO2 promoted the phase transition and the transition proportion of Form III increased with the CO2 pressure increasing. Form III completely transformed into Form I, at 18 MPa. Moreover, supercritical CO2 could induce the amorphous region to transit into Form I,. The probable mechanism of the CO2 effects on Form III multiple transitions was also proposed. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source] Purification, crystallization, X-ray diffraction analysis and phasing of a Fab fragment of monoclonal neuroantibody ,D11 against nerve growth factorACTA CRYSTALLOGRAPHICA SECTION D, Issue 7 2004Sonia Covaceuszach The rat monoclonal neuroantibody ,D11 is a potent antagonist that prevents the binding of nerve growth factor (NGF) to its tyrosine kinase A receptor (TrkA) in a variety of systems, most notably in two in vivo systems linked to crucial pathological states, such as Alzheimer's disease and HIV infection. To provide further insights into the mechanism of action of this potentially therapeutic monoclonal antibody, structural studies of the antigen-binding fragment (Fab) of ,D11 were performed. ,D11 IgG2a immunoglobulin was obtained from hybridomas by in vitro tissue culture. The ,D11 Fab crystallizes in two crystal forms. Form I belongs to space group P1, with unit-cell parameters a = 42.7, b = 50.6, c = 102.7,Å, , = 82.0, , = 89.1, , = 86.0°. With two molecules in the asymmetric unit, VM is 2.3,Å3,Da,1 and the solvent content is 46%. A complete data set has been collected at 2.7,Å resolution on beamline XRD-1 (ELETTRA, Trieste, Italy). Form II belongs to space group C2, with unit-cell parameters a = 114.8, b = 69.4, c = 64.10,Å, , = 117.0°. With one molecule in the asymmetric unit, VM is 2.4,Å3,Da,1 and the solvent content is 48%. A complete data set has been collected at 1.7,Å resolution on beamline ID14-1 (ESRF, Grenoble, France). Phasing was successfully performed by Patterson search techniques and refinement of the structures is currently under way. Crystal forms I and II display a close-packing pattern. [source] Crystallization of Saccharomyces cerevisiae,-mannosidase, a cargo protein of the Cvt pathwayACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 6 2009Yasunori Watanabe Saccharomyces cerevisiae,-mannosidase (Ams1) is a cargo protein that is transported to the vacuole by the cytoplasm-to-vacuole targeting (Cvt) pathway during conditions of growth and by autophagy during conditions of starvation. After transport to the vacuole, Ams1 functions as a resident hydrolase. Ams1 has been overexpressed in the methylotrophic yeast Pichia pastoris, purified and crystallized in two crystal forms. Form I belongs to space group P21, with unit-cell parameters a = 145.7, b = 127.7, c = 164.0,Å, , = 101.5°. Form II belongs to space group I222 or I212121, with unit-cell parameters a = 127.9, b = 163.7, c = 291.5,Å. Diffraction data were collected from these crystals to a resolution of 3.3,Å for form I and of 2.6,Å for form II using synchrotron radiation. [source] Crystallization of Saccharomyces cerevisiae aminopeptidase 1, the major cargo protein of the Cvt pathwayACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 3 2007Wakana Adachi The vacuole hydrolase aminopeptidase 1 (Ape1) is a cargo protein transported to the vacuole by the cytosol-to-vacuole targeting (Cvt) pathway during conditions of growth and by autophagy during conditions of starvation. After transport to the vacuole, Ape1 is processed into mature Ape1 (mApe1). mApe1 has been expressed, purified and crystallized in two crystal forms. Form I belongs to space group P21, with unit-cell parameters a = 120.6, b = 219.5, c = 133.1,Å, , = 116.5°. Form II belongs to space group R3, with unit-cell parameters a = 141.2, c = 349.4,Å. Diffraction data were collected from these crystals to a resolution of 2.5,Å for form I and 1.83,Å for form II. Self-rotation functions and the volume-to-weight ratio values suggest that forms I and II contain 12 and four mApe1 molecules per asymmetric unit, respectively, and that mApe1 exists as a tetrahedral dodecamer in both crystal forms. [source] Pergolide Mesylate Form II.CHEMINFORM, Issue 10 2004Alexandr Jegorov Abstract For Abstract see ChemInform Abstract in Full Text. [source] The Oxidative Damage of Plasmid DNA by Ascorbic Acid Derivatives in vitro: The First Research on the Relationship between the Structure of Ascorbic Acid and the Oxidative Damage of Plasmid DNACHEMISTRY & BIODIVERSITY, Issue 9 2006Pei-Yan Liu Abstract To study the structure,function relationship of the oxidative-damage effect of ascorbic acid, we have focused on the interaction between plasmid DNA pUC19 and a series of ascorbic acid derivatives modified on different OH groups in the presence of transition metal ions. Some ascorbic acid derivatives can selectively cleave plasmid DNA from Form I to Form II in the presence of low concentration of Cu2+ just like ascorbic acid itself, while other derivatives oxidatively damage plasmid DNA slightly. We found that those derivatives with unattached 2-OH and 3-OH groups retain the ability to cleave the plasmid DNA. The derivatives that have been methylated on 2-OH or 3-OH can only cleave plasmid DNA softly, and those derivatives that have been protected on both 2-OH and 3-OH can hardly exert an oxidative damage on plasmid DNA under the same condition. Form these results, we can draw the conclusion that 2-OH and 3-OH groups of the ascorbic acid molecule contribute most to this biological activity. [source] Crystal polymorphism in a carbamazepine derivative: OxcarbazepineJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 2 2010Katie M. Lutker Abstract Although crystal polymorphism of carbamazepine (CBZ), an anticonvulsant used to treat epilepsy, has been known for decades, the phenomenon has only recently been noted for its keto-derivative oxcarbazepine (OCB). Here it is demonstrated that OCB possesses at least three anhydrous polymorphs. Although all forms are morphologically similar, making differentiation between crystal modifications by optical microscopy difficult, powder X-ray diffraction, Raman spectroscopy, and thermomicroscopy show distinctive differences. These techniques provide an efficient method of distinguishing between the three polymorphs. The crystal structure of form II of OCB is reported for the first time and the structure of form I has been redetermined at low temperature. Remarkably, both the molecular conformation and crystal packing of form II are in excellent agreement with the blind prediction made in 2007. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99:794,803, 2010 [source] Conformational polymorphism in aripiprazole: Preparation, stability and structure of five modificationsJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 6 2009Doris E. Braun Abstract Five phase-pure modifications of the antipsychotic drug aripiprazole were prepared and characterized by thermal analysis, vibrational spectroscopy and X-ray diffractometry. All modifications can be produced from solvents, form I additionally by heating of form X° to ,120°C (solid,solid transformation) and form III by crystallization from the melt. Thermodynamic relationships between the polymorphs were evaluated on the basis of thermochemical data and visualized in a semi-schematic energy/temperature diagram. At least six of the ten polymorphic pairs are enantiotropically and two monotropically related. Form X° is the thermodynamically stable modification at 20°C, form II is stable in a window from about 62,77°C, and form I above 80°C (high-temperature form). Forms III and IV are triclinic (), I and X° are monoclinic (P21) and form II orthorhombic (Pna21). Each polymorph exhibits a distinct molecular conformation, and there are two fundamental N,HO hydrogen bond synthons (catemers and dimers). Hirshfeld surface analysis was employed to display differences in intermolecular short contacts. A high kinetic stability was observed for three metastable polymorphs which can be categorized as suitable candidates for the development of solid dosage forms. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:2010,2026, 2009 [source] In situ measurement of solvent-mediated phase transformations during dissolution testingJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 12 2006Jaakko Aaltonen Abstract In this study, solvent-mediated phase transformations of theophylline (TP) and nitrofurantoin (NF) were measured in a channel flow intrinsic dissolution test system. The test set-up comprised simultaneous measurement of drug concentration in the dissolution medium (with UV-Vis spectrophotometry) and measurement of the solid-state form of the dissolving solid (in situ with Raman spectroscopy). The solid phase transformations were also investigated off-line with scanning electron microscopy. TP anhydrate underwent a transformation to TP monohydrate, and NF anhydrate (form ,) to NF monohydrate (form II). Transformation of TP anhydrate to TP monohydrate resulted in a clear decrease in the dissolution rate, while the transformation of NF anhydrate (form ,) to NF monohydrate (form II) could not be linked as clearly to changes in the dissolution rate. The transformation of TP was an order of magnitude faster than that of NF. The presence of a water absorbing excipient, microcrystalline cellulose, was found to delay the onset of the transformation of TP anhydrate. Combining the measurement of drug concentration in the dissolution medium with the solid phase measurement offers a deeper understanding of the solvent-mediated phase transformation phenomena during dissolution. © 2006 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 95:2730,2737, 2006 [source] Blind crystal structure prediction of a novel second polymorph of 1-hydroxy-7-azabenzotriazoleACTA CRYSTALLOGRAPHICA SECTION B, Issue 4 2006Harriott Nowell The commercially available peptide coupling reagent 1-hydroxy-7-azabenzotriazole has been shown to crystallize in two polymorphic forms. The two polymorphs differ in their hydrogen-bonding motif, with form I having an (10) dimer motif and form II having a C(5) chain motif. The previously unreported form II was used as an informal blind test of computational crystal structure prediction for flexible molecules. The crystal structure of form II has been successfully predicted blind from lattice-energy minimization calculations following a series of searches using a large number of rigid conformers. The structure for form II was the third lowest in energy with form I found as the global minimum, with the energy calculated as the sum of the ab initio intramolecular energy penalty for conformational distortion and the intermolecular lattice energy which is calculated from a distributed multipole representation of the charge density. The predicted structure was sufficiently close to the experimental structure that it could be used as a starting model for crystal structure refinement. A subsequent limited polymorph screen failed to yield a third polymorphic form, but demonstrated that alcohol solvents are implicated in the formation of the form I dimer structure. [source] Dimorphic forms of 3,6-dinitrodurene in a single space groupACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2009José Alberto Galicia Aguilar 3,6-Dinitrodurene (1,2,4,5-tetramethyl-3,6-dinitrobenzene), C10H12N2O4, has been crystallized in two polymorphic forms which may be distinguished by their colours in the solid state. Polymorph I gives clear colourless prismatic crystals, while polymorph II crystallizes in the dark and under an inert atmosphere as irregular purple blocks. Both forms belong to the space group C2/c, with both asymmetric units containing two half-molecules. One molecule is located on an inversion centre and the other lies on a twofold axis. The polymorphism arises from different orientations of the twofold axis: in form I, this axis passes through the mid-points of two C,C bonds of the benzene ring and, as a consequence, all atoms in the asymmetric unit are in general positions. In form II, the N atoms of the nitro groups and the Cipso atoms are located on the binary axis. Comparing phases I and II, slightly different conformations are observed for the nitro substituents, while the stacking structures are very similar. [source] Two crystal forms of mesogenic bis(4,-cyanobiphenyl-4-yl) butanedioateACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2009Kayako Hori The title compound, C30H20N2O4, exhibits a nematic phase in the wide temperature range between 498.5 and 538.6,K, in spite of the short linker moiety. Two crystal forms have been found. In both forms, the molecule is centrosymmetric. Form I has a planar biphenyl group, while form II has a twisted biphenyl group with a twist angle of 34.75,(6)°. The packing modes are also different. In form I the long molecular axes are tilted with respect to each other at about 30°, while in form II the long molecular axes have an almost parallel arrangement. [source] trans -Chlorido(phenyl)bis(triphenylphosphine)nickel(II) and its 1:1 cocrystal with chloridobis(triphenylphosphine)nickel(I)ACTA CRYSTALLOGRAPHICA SECTION C, Issue 2 2009Lidong Li Two conformational polymorphs of trans -chlorido(phenyl)bis(triphenylphosphine)nickel(II), [Ni(C6H5)Cl(C18H15P)2], (1), viz. orange needle-shaped crystals (form I) and brown prism-shaped crystals (form II), were obtained under different crystallization conditions from a mixture of toluene and n -hexane, and characterized by single-crystal X-ray diffraction at low temperature. These two forms were compared with that published previously [Zeller, Herdtweck & Strassner (2003). Eur. J. Inorg. Chem. pp. 1802,1806], characterized at room temperature. Additionally, blue,green prisms of a 1:1 cocrystal of complex (1) with chloridobis(triphenylphosphine)nickel(I), (2), viz.trans -chlorido(phenyl)bis(triphenylphosphine)nickel(II),chloridobis(triphenylphosphine)nickel(I) (1/1), [Ni(C6H5)Cl(C18H15P)2]·[NiCl(C18H15P)2], (3), were obtained concomitantly with form I. In forms I and II, as well as in the cocrystal, the overall crystal packings are determined by an energetic interplay between intramolecular torsions and weak intermolecular C,H..., and C,H...Cl interactions. [source] Polymorph of {2-[(2-hydroxyethyl)iminiomethyl]phenolato-,O}dioxido{2-[(2-oxidoethyl)iminomethyl]phenolato-,3O,N,O,}molybdenum(VI)ACTA CRYSTALLOGRAPHICA SECTION C, Issue 2 2008Dominique Agustin A second polymorphic form (form I) of the previously reported compound {2-[(2-hydroxyethyl)iminiomethyl]phenolato-,O}dioxido{2-[(2-oxidoethyl)iminomethyl]phenolato-,3O,N,O,}molybdenum(VI) (form II), [Mo(C9H9NO2)O2(C9H11NO2)], is presented. The title structure differs from the previously reported polymorph [G,owiak, Jerzykiewicz, Sobczak & Zió,kowski (2003). Inorg. Chim. Acta, 356, 387,392] by the fact that the asymmetric unit contains three molecules linked by O,H...O hydrogen bonds. These trimeric units are further linked through O,H...O hydrogen bonds to form a chain parallel to the [11] direction. As in the previous polymorph, each molecule is built up from an MoO22+ cation surrounded by an O,N,O,-tridentate ligand (O,C6H4CH=NCH2CH2O,) and weakly coordinated by a second zwitterionic ligand (O,C6H4CH=N+HC2H4OH). All complexes are chiral with the absolute configuration at Mo being C or A. The main difference between the two polymorphs results from the alternation of the chirality at Mo within the chain. [source] Crystal structure reveals two alternative conformations in the active site of ribonuclease Sa2ACTA CRYSTALLOGRAPHICA SECTION D, Issue 7 2004Jozef Three different strains of Streptomyces aureofaciens produce the homologous ribonucleases Sa, Sa2 and Sa3. The crystal structures of ribonuclease Sa (RNase Sa) and its complexes with mononucleotides have previously been reported at high resolution. Here, the structures of two crystal forms (I and II) of ribonuclease Sa2 (RNase Sa2) are presented at 1.8 and 1.5 Å resolution. The structures were determined by molecular replacement using the coordinates of RNase Sa as a search model and were refined to R factors of 17.5 and 15.0% and Rfree factors of 21.8 and 17.2%, respectively. The asymmetric unit of crystal form I contains three enzyme molecules, two of which have similar structures to those seen for ribonuclease Sa, with Tyr87 at the bottom of their active sites. In the third molecule, Tyr87 has moved substantially: the CA atom moves almost 5,Å and the OH of the side chain moves 10,Å, inserting itself into the active site of a neighbouring molecule at a similar position to that observed for the nucleotide base in RNase Sa complexes. The asymmetric unit of crystal form II contains two Sa2 molecules, both of which are similar to the usual Sa structures. In one molecule, two main-chain conformations were modelled in the ,-helix. Finally, a brief comparison is made between the conformations of the Sa2 molecules and those of 34 independent molecules taken from 20 structures of ribonuclease Sa and two independent molecules taken from two structures of ribonuclease Sa3 in various crystal forms. [source] Crystallization of the Mycobacterium tuberculosis cell-division protein FtsZACTA CRYSTALLOGRAPHICA SECTION D, Issue 12 2000Adelaine K. W. Leung Mycobacterium tuberculosis FtsZ (MtbFtsZ), an essential protein in bacterial cell division, has been crystallized in the presence of a new inhibitor of MtbFtsZ polymerization and GTPase activity, ethyl (6-amino-2,3-dihydro-4-phenyl-1H -pyrido[4,3- b][1,4]diazepin-8-yl)carbamate (SRI-7614). Crystals of the MtbFtsZ,SRI-7614 complex (form I, 30% polyethylene glycol 4000, 0.1,M sodium citrate pH 5.6, 0.2,M NH4OAc, 293,K) belong to space group P61 or P65, with unit-cell parameters a = 88.78, c = 178.02,Å, and diffract to 2.3,Å resolution. A second crystal form, of the GDP complex, grows in the presence or absence of Mg2+ from PEG 4000 at 277,K or from (NH4)2SO4 at 293,K, respectively (form II, space group P6222 or P6422, with unit-cell parameters a = 135.02, c = 328.97,Å or a = 129.30, c = 327.97,Å, respectively). Complete data sets to ,7,Å resolution have been collected from both. Exceptional form II crystals diffract to at least 4.5,Å resolution. Determination of the MtbFtsZ structure may advance the design of improved inhibitors of FtsZ polymerization. [source] Structural studies of MIP synthaseACTA CRYSTALLOGRAPHICA SECTION D, Issue 3 2000Adam J. Stein The conversion of glucose 6-phosphate to 1- l - myo -inositol 1-phosphate (MIP) by 1- l - myo -inositol 1-phosphate synthase (MIP synthase) is the first committed and rate-limiting step in the de novo biosynthesis of inositol in all eukaryotes. The importance of inositol-containing molecules both as membrane components and as critical second messenger signal-transduction species make the function and regulation of this enzyme important for a host of biologically important cellular functions including proliferation, neurostimulation, secretion and contraction. MIP synthase has been overexpressed in Esherichia coli and purified to homogeneity by chromatographic methods. Two crystal forms of MIP synthase were obtained by the hanging-drop vapor-diffusion method. Native data sets for both crystal forms were collected in-house on a Rigaku R-AXIS IIC imaging-plate detector. Crystal form I belongs to space group C2, with unit-cell parameters a = 153.0, b = 96.6, c = 122.6,Å, , = 126.4°, and diffracts to 2.5,Å resolution. Crystal form II belongs to space group P21, with unit-cell parameters a = 94.5, b = 186.2, c = 86.5,Å, , = 110.5°, and diffracts to 2.9,Å resolution. [source] Crystallization and preliminary X-ray analysis of 4-pyridoxolactonase from Mesorhizobium lotiACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 9 2009Sayoko Matsuda 4-Pyridoxolactonase from Mesorhizobium loti MAFF303099 has been overexpressed in Escherichia coli. The recombinant enzyme was purified and was crystallized by the sitting-drop vapour-diffusion method using PEG 4000 and ammonium sulfate as precipitants. Crystals of the free enzyme (form I) and of the 5-pyridoxolactone-bound enzyme (form II) grew under these conditions. Crystals of form I diffracted to 2.0,Å resolution and belonged to the monoclinic space group C2, with unit-cell parameters a = 77.93, b = 38.88, c = 81.60,Å, , = 117.33°. Crystals of form II diffracted to 1.9,Å resolution and belonged to the monoclinic space group C2, with unit-cell parameters a = 86.24, b = 39.35, c = 82.68,Å, , = 118.02°. The calculated VM values suggested that the asymmetric unit contains one molecule in both crystal forms. [source] Crystallization and preliminary crystallographic analysis of the bacterial capsule assembly-regulating tyrosine phosphatases Wzb of Escherichia coli and Cps4B of Streptococcus pneumoniaeACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 8 2009Hexian Huang Bacterial tyrosine kinases and their cognate phosphatases are key players in the regulation of capsule assembly and thus are important virulence determinants of these bacteria. Examples of the kinase/phosphatase pairing are found in Gram-negative bacteria such as Escherichia coli (Wzc and Wzb) and in Gram-positive bacteria such as Streptococcus pneumoniae (CpsCD and CpsB). Although Wzb and Cps4B are both predicted to dephosphorylate the C-terminal tyrosine cluster of their cognate tyrosine kinase, they appear on the basis of protein sequence to belong to quite different enzyme classes. Recombinant purified proteins Cps4B of S. pneumoniae TIGR4 and Wzb of E. coli K-30 have been crystallized. Wzb crystals belonged to space-group family P3x21 and diffracted to 2.7,Å resolution. Crystal form I of Cps4B belonged to space-group family P4x212 and diffracted to 2.8,Å resolution; crystal form II belonged to space group P212121 and diffracted to 1.9,Å resolution. [source] Crystallization of Saccharomyces cerevisiae,-mannosidase, a cargo protein of the Cvt pathwayACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 6 2009Yasunori Watanabe Saccharomyces cerevisiae,-mannosidase (Ams1) is a cargo protein that is transported to the vacuole by the cytoplasm-to-vacuole targeting (Cvt) pathway during conditions of growth and by autophagy during conditions of starvation. After transport to the vacuole, Ams1 functions as a resident hydrolase. Ams1 has been overexpressed in the methylotrophic yeast Pichia pastoris, purified and crystallized in two crystal forms. Form I belongs to space group P21, with unit-cell parameters a = 145.7, b = 127.7, c = 164.0,Å, , = 101.5°. Form II belongs to space group I222 or I212121, with unit-cell parameters a = 127.9, b = 163.7, c = 291.5,Å. Diffraction data were collected from these crystals to a resolution of 3.3,Å for form I and of 2.6,Å for form II using synchrotron radiation. [source] Crystallization of carbohydrate oxidase from Microdochium nivaleACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 6 2009Jarmila Du Microdochium nivale carbohydrate oxidase was produced by heterologous recombinant expression in Aspergillus oryzae, purified and crystallized. The enzyme crystallizes with varying crystal morphologies depending on the crystallization conditions. Several different crystal forms were obtained using the hanging-drop vapour-diffusion method, two of which were used for diffraction measurements. Hexagon-shaped crystals (form I) diffracted to 2.66,Å resolution, with unit-cell parameters a = b = 55.7, c = 610.4,Å and apparent space group P6222. Analysis of the data quality showed almost perfect twinning of the crystals. Attempts to solve the structure by molecular replacement did not give satisfactory results. Recently, clusters of rod-shaped crystals (form II) were grown in a solution containing PEG MME 550. These crystals belonged to the monoclinic system C2, with unit-cell parameters a = 132.9, b = 56.6, c = 86.5,Å, , = 95.7°. Data sets were collected to a resolution of 2.4,Å. The structure was solved by the molecular-replacement method. Model refinement is currently in progress. [source] Crystallization and preliminary X-ray analysis of d -2-hydroxyacid dehydrogenase from Haloferax mediterraneiACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 4 2009J. Domenech d -2-Hydroxyacid dehydrogenase (D2-HDH) from Haloferax mediterranei has been overexpressed in Escherichia coli, solubilized in 8,M urea and refolded by rapid dilution. The protein was purified and crystallized by the hanging-drop vapour-diffusion method using ammonium sulfate or PEG 3350 as precipitant. Two crystal forms representing the free enzyme and the nonproductive ternary complex with ,-ketohexanoic acid and NAD+ grew under these conditions. Crystals of form I diffracted to beyond 3.0,Å resolution and belonged to the monoclinic space group P21, with unit-cell parameters a = 66.0, b = 119.6, c = 86.2,Å, , = 96.3°. Crystals of form II diffracted to beyond 2.0,Å resolution and belonged to the triclinic space group P1, with unit-cell parameters a = 66.5, b = 75.2, c = 77.6,Å, , = 109.1, , = 107.5, , = 95.9°. The calculated values for VM and analysis of the self-rotation and self-Patterson functions suggest that the asymmetric unit in both crystal forms contains two dimers related by pseudo-translational symmetry. [source] Crystallization and preliminary characterization of the Thermus thermophilus RNA helicase Hera C-terminal domainACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 3 2009Markus G. Rudolph Heat-resistant RNA-dependent ATPase (Hera) from Thermus thermophilus is a DEAD-box RNA helicase. Two constructs encompassing the second RecA-like domain and the C-terminal domain of Hera were overproduced in Escherichia coli and purified to homogeneity. Single crystals of both Hera constructs were obtained in three crystal forms. A tetragonal crystal form belonged to space group P41212, with unit-cell parameters a = 65.5, c = 153.0,Å, and contained one molecule per asymmetric unit. Two orthorhombic forms belonged to space group P212121, with unit-cell parameters a = 62.8, b = 70.9, c = 102.3,Å (form I) and a = 41.6, b = 67.6, c = 183.5,Å (form II). Both orthorhombic forms contained two molecules per asymmetric unit. All crystals diffracted X-rays to beyond 3,Å resolution, but the tetragonal data sets displayed high Wilson B values and high mean |E2, 1| values, indicating potential disorder and anisotropy. The tetragonal crystal was phased by MAD using a single selenium site. [source] Crystallization of Saccharomyces cerevisiae aminopeptidase 1, the major cargo protein of the Cvt pathwayACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 3 2007Wakana Adachi The vacuole hydrolase aminopeptidase 1 (Ape1) is a cargo protein transported to the vacuole by the cytosol-to-vacuole targeting (Cvt) pathway during conditions of growth and by autophagy during conditions of starvation. After transport to the vacuole, Ape1 is processed into mature Ape1 (mApe1). mApe1 has been expressed, purified and crystallized in two crystal forms. Form I belongs to space group P21, with unit-cell parameters a = 120.6, b = 219.5, c = 133.1,Å, , = 116.5°. Form II belongs to space group R3, with unit-cell parameters a = 141.2, c = 349.4,Å. Diffraction data were collected from these crystals to a resolution of 2.5,Å for form I and 1.83,Å for form II. Self-rotation functions and the volume-to-weight ratio values suggest that forms I and II contain 12 and four mApe1 molecules per asymmetric unit, respectively, and that mApe1 exists as a tetrahedral dodecamer in both crystal forms. [source] | ||||||||||