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Abstract
Determining whether magma fragments during eruption remains a seminal challenge in volcanology. There is a robust paradigm for fragmentation of high viscosity, silicic magmas, however little is known about the fragmentation behaviour of lower viscosity systems—the most abundant form of volcanism on Earth and on other planetary bodies and satellites. Here we provide a quantitative model, based on experiments, for the non-brittle, fluid dynamic induced fragmentation of low viscosity melts. We define the conditions under which extensional thinning or liquid break-up can be expected. We show that break-up, both in our experiments and natural eruptions, occurs by both viscous and capillary instabilities operating on contrasting timescales. These timescales are used to produce a universal break-up criterion valid for low viscosity melts such as basalt, kimberlite and carbonatite. Lastly, we relate these break-up instabilities to changes in eruptive behaviour, the associated natural hazard and ultimately the deposits formed. Determining if a volcanic eruption will behave effusively or explosively is crucial for predicting the potential hazard type and for planning effective mitigation. Here, the authors present a universal, fluid dynamic induced, break-up criterion for low viscosity melts.
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Affiliation(s)
- T J Jones
- Department of Earth, Environmental and Planetary Sciences, Rice University, 6100 Main Street, Houston, TX, 77005, USA. .,Department of Earth Sciences, Durham University, Lower Mountjoy, South Road, Durham, DH1 3LE, UK.
| | - C D Reynolds
- School of Chemistry, The University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - S C Boothroyd
- Department of Chemistry, Durham University, Lower Mountjoy, South Road, Durham, DH1 3LE, UK
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Wright LM, Wood SD, Reynolds CD, Rizkallah PJ, Peumans WJ, Van Damme EJ, Allen AK. Purification, crystallization and preliminary X-ray analysis of a mannose-binding lectin from bluebell (Scilla campanulata) bulbs. Acta Crystallogr D Biol Crystallogr 2005; 52:1021-3. [PMID: 15299614 DOI: 10.1107/s0907444996006889] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Crystals have been grown of a mannose-specific lectin from bluebell (Scilla campanulata) bulbs in a form suitable for X-ray diffraction studies. The crystals, which diffract to high resolution, grew in hanging drops by vapour diffusion, equilibrating with a solution of 70% saturated ammonium sulfate at pH 4.7-4.8 at 293 K, in the absence of any mannose saccharides. Crystals are orthorhombic, P2(1)2(1)2, with unit-cell dimensions a = 70.78, b = 93.69, c = 46.92 A. The functional lectin molecule is organized as a tetramer of four identical 14 kDa subunits, with only two subunits in the asymmetric unit. Data to 1.86 A resolution have been recorded and the structure determined by the molecular replacement method.
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Affiliation(s)
- L M Wright
- School of Biomolecular Sciences, Liverpool John Moores University, England.
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3
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Chantalat L, Nicholson JM, Lambert SJ, Reid AJ, Donovan MJ, Reynolds CD, Wood CM, Baldwin JP. Structure of the histone-core octamer in KCl/phosphate crystals at 2.15 A resolution. Acta Crystallogr D Biol Crystallogr 2003; 59:1395-407. [PMID: 12876341 DOI: 10.1107/s0907444903011880] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2002] [Accepted: 05/29/2003] [Indexed: 11/10/2022]
Abstract
The structure of the native chicken histone octamer, crystallized in 2 M KCl, 1.35 M potassium phosphate pH 6.9, has been refined at 2.15 A resolution to a final R factor of 21.4% and an R(free) of 25.2%. Unique crystal-packing interactions between histone-core octamers are strong and one of them (area 4000 A(2)) involves two chloride ions and direct interactions between six acidic amino-acid residues on one octamer and the equivalent number of basic residues on the next. These interactions are on the structured part of the octamer (not involving tails). Five phosphate ions, 23 chloride ions and 437 water molecules have been identified in the structure. The phosphate and some chloride ions bind to basic amino-acid residues that interact with DNA in the nucleosome. The binding of most of the anions and the packing interactions are unique to these crystals. In other respects, and including the positions of four chloride ions, the octamer structure is very close to that of octamers in nucleosome-core particle crystals, particularly with respect to 'docking' sequences of the histone H2As and H4s. These sequences together with the H2B-H4 four-helix bundles stabilize the histone structure in the nucleosome and prevent the dissociation of the (H2A-H2B) dimers from the (H3-H4)(2) tetramer. Possible reasons why this happens at high salt in the absence of DNA are given.
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Affiliation(s)
- L Chantalat
- Structural Biology, Galderma RandD, 635 Route des Lucioles, BP 87F-06902 Sophia Antipolis CEDEX, France
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4
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Wright LM, Reynolds CD, Rizkallah PJ, Allen AK, Van Damme EJ, Donovan MJ, Peumans WJ. Structural characterisation of the native fetuin-binding protein Scilla campanulata agglutinin: a novel two-domain lectin. FEBS Lett 2000; 468:19-22. [PMID: 10683433 DOI: 10.1016/s0014-5793(00)01109-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The three-dimensional structure of a 244-residue, multivalent, fetuin-binding lectin, SCAfet, isolated from bluebell (Scilla campanulata) bulbs, has been solved at 3.3 A resolution by molecular replacement using the coordinates of the 119-residue, mannose-binding lectin, SCAman, also from bluebell bulbs. Unlike most monocot mannose-binding lectins, such as Galanthus nivalis agglutinin from snowdrop bulbs, which fold into a single domain, SCAfet contains two domains with approximately 55% sequence identity, joined by a linker peptide. Both domains are made up of a 12-stranded beta-prism II fold, with three putative carbohydrate-binding sites, one on each subdomain. SCAfet binds to the complex saccharides of various animal glycoproteins but not to simple sugars.
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Affiliation(s)
- L M Wright
- School of Biomolecular Sciences, Max Perutz Building, Liverpool John Moores University, Liverpool, UK
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5
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Lisgarten JN, Chattopadhyay TK, Pitts JE, Palmer RA, Reynolds CD, Dao-Thi MH, Van Driessche E, Beeckmans S. Crystallization of Helix pomatia agglutinin (HPA), a protein from the edible snail. Acta Crystallogr D Biol Crystallogr 1999; 55:1903-5. [PMID: 10531490 DOI: 10.1107/s0907444999007957] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Crystals of Helix pomatia agglutinin (HPA) have been grown by the hanging-drop technique using polyethylene glycol as the precipitant at 293 K. Over a period of one to two weeks the crystals grew to maximum dimensions of 0.10 x 0.05 x 0.02 mm. The crystals belong to space group P6(3)22, with unit-cell dimensions a = b = 63.3, c = 105. 2 A and Z = 12 identical monomers of M(r) = 13 kDa, aggregating into two 78 kDa hexameric protein molecules per unit cell, each with symmetry 32 (D(3)). The diffraction pattern extends to 3.6 A at 293 K.
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Affiliation(s)
- J N Lisgarten
- Department of Crystallography, Birkbeck College, Malet Street, London WC1E 7HX, England
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6
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Sauerborn MK, Wright LM, Reynolds CD, Grossmann JG, Rizkallah PJ. Insights into carbohydrate recognition by Narcissus pseudonarcissus lectin: the crystal structure at 2 A resolution in complex with alpha1-3 mannobiose. J Mol Biol 1999; 290:185-99. [PMID: 10388566 DOI: 10.1006/jmbi.1999.2862] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Carbohydrate recognition by monocot mannose-binding lectins was studied via the crystal structure determination of daffodil (Narcissus pseudonarcissus) lectin. The lectin was extracted from daffodil bulbs, and crystallised in the presence of alpha-1,3 mannobiose. Molecular replacement methods were used to solve the structure using the partially refined model of Hippeastrum hybrid agglutinin as a search model. The structure was refined at 2.0 A resolution to a final R -factor of 18.7 %, and Rfreeof 26.7 %. The main feature of the daffodil lectin structure is the presence of three fully occupied binding pockets per monomer, arranged around the faces of a triangular beta-prism motif. The pockets have identical topology, and can bind mono-, di- or oligosaccharides. Strand exchange forms tightly bound dimers, and higher aggregation states are achieved through hydrophobic patches on the surface, completing a tetramer with internal 222-symmetry. There are therefore 12 fully occupied binding pockets per tetrameric cluster. The tetramer persists in solution, as shown with small-angle X-ray solution scattering. Extensive sideways and out-of-plane interactions between tetramers, some mediated via the ligand, make up the bulk of the lattice contacts.A fourth binding site was also observed. This is unique and has not been observed in similar structures. The site is only partially occupied by a ligand molecule due to the much lower binding affinity. A comparison with the Galanthus nivalis agglutinin/mannopentaose complex suggests an involvement of this site in the recognition mechanism for naturally occurring glycans.
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Affiliation(s)
- M K Sauerborn
- CCLRC Daresbury Laboratory, Keckwick Lane, Daresbury, Warrington, Cheshire, WA4 4AD, UK
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7
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Wood SD, Wright LM, Reynolds CD, Rizkallah PJ, Allen AK, Peumans WJ, Van Damme EJ. Structure of the native (unligated) mannose-specific bulb lectin from Scilla campanulata (bluebell) at 1.7 A resolution. Acta Crystallogr D Biol Crystallogr 1999; 55:1264-72. [PMID: 10393293 DOI: 10.1107/s0907444999005326] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The X-ray crystal structure of native Scilla campanulata agglutinin, a mannose-specific lectin from bluebell bulbs and a member of the Liliaceae family, has been determined by molecular replacement and refined to an R value of 0.186 at 1.7 A resolution. The lectin crystallizes in space group P21212 with unit-cell parameters a = 70. 42, b = 92.95, c = 46.64 A. The unit cell contains eight protein molecules of Mr = 13143 Da (119 amino-acid residues). The asymmetric unit comprises two chemically identical molecules, A and B, related by a non-crystallographic twofold axis perpendicular to c. This dimer further associates by crystallographic twofold symmetry to form a tetramer. The fold of the polypeptide backbone closely resembles that found in the lectins from Galanthus nivalis (snowdrop) and Hippeastrum (amaryllis) and contains a threefold symmetric beta-prism made up of three antiparallel four-stranded beta-sheets. Each of the four-stranded beta-sheets (I, II and III) possesses a potential saccharide-binding site containing conserved residues; however, site II has two mutations relative to sites I and III which may prevent ligation at this site. Our study provides the first accurate and detailed description of a native (unligated) structure from this superfamily of mannose-specific bulb lectins and will allow comparisons with a number of lectin-saccharide complexes which have already been determined or are currently under investigation.
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Affiliation(s)
- S D Wood
- School of Biomolecular Sciences, Max Perutz Building, Liverpool John Moores University, Liverpool L3 3AF, England
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Wright LM, Van Damme EJ, Barre A, Allen AK, Van Leuven F, Reynolds CD, Rouge P, Peumans WJ. Isolation, characterization, molecular cloning and molecular modelling of two lectins of different specificities from bluebell (Scilla campanulata) bulbs. Biochem J 1999; 340 ( Pt 1):299-308. [PMID: 10229686 PMCID: PMC1220249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Two lectins have been isolated from bluebell (Scilla campanulata) bulbs. From their isolation by affinity chromatography, they are characterized as a mannose-binding lectin (SCAman) and a fetuin-binding lectin (SCAfet). SCAman preferentially binds oligosaccharides with alpha(1,3)- and alpha(1,6)-linked mannopyranosides. It is a tetramer of four identical protomers of approx. 13 kDa containing 119 amino acid residues; it is not glycosylated. The fetuin-binding lectin (SCAfet), which is not inhibited by any simple sugars, is also unglycosylated. It is a tetramer of four identical subunits of approx. 28 kDa containing 244 residues. Each 28 kDa subunit is composed of two 14 kDa domains. Both lectins have been cloned from a cDNA library and sequenced. X-ray crystallographic analysis and molecular modelling studies have demonstrated close relationships in sequence and structure between these lectins and other monocot mannose-binding lectins. A refined model of the molecular evolution of the monocot mannose-binding lectins is proposed.
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Affiliation(s)
- L M Wright
- School of Biomolecular Sciences, Liverpool John Moores University, Liverpool L3 3AF, UK
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9
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Wright LM, Rizkallah PJ, Wood SD, Reynolds CD. Scilla campanulata agglutinin crystallized in complex with the trimannoside alpha-D-man-(1-->6)-[alpha-D-man-(1-->3)]-alpha-D-Man. Acta Crystallogr D Biol Crystallogr 1998; 54:665-7. [PMID: 9761869 DOI: 10.1107/s0907444997019859] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The monocot mannose-specific lectin, Scilla campanulata agglutinin (SCA), from bluebell bulbs has a strong affinity for alpha1,3- and alpha1,6-linked mannosyl residues. SCA has been co-crystallized with the trisaccharide alpha-D-mannopyranosyl-(1-->6)-alpha-D-mannopyranosyl-(1-->3)-alpha-D -mannopyranoside ¿alpha-D-Man-(1-->6)-[alpha-D-Man-(1-->3)]-alpha-D-Man¿, the core structure of biantennary N-linked oligosaccharides. Crystals of the complex were obtained by the hanging-drop vapour-diffusion technique. A complete data set to 2.5 A resolution has been collected at 100 K, using a MAR image-plate system at a synchrotron source, from crystals which belong to the space group C2 with unit-cell dimensions a = 99.38, b = 119.86, c = 77.10 A and beta = 105.56 degrees. Use of a CCD detector with cryo-cooled crystals improved the resolution to 2.3 A. A molecular replacement solution, with the 2.5 A data set, using the native SCA as a search model was obtained, with six subunits per asymmetric unit.
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Affiliation(s)
- L M Wright
- School of Biomolecular Sciences, Max Perutz Building, Liverpool John Moores University, Liverpool L3 3AF, England.
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Wright LM, Wood SD, Reynolds CD, Rizkallah PJ, Allen AK. Crystallization and preliminary structural studies of Scilla campanulata lectin complexed with alpha1-6 mannobiose. Acta Crystallogr D Biol Crystallogr 1998; 54:90-2. [PMID: 9761821 DOI: 10.1107/s0907444997007063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Recent work has shown that Scilla campanulata agglutinin from bluebell bulbs has a strong affinity for alpha(1,3)- and alpha(1,6)-linked mannosyl residues and possesses moderate antiretroviral activity. This lectin has been crystallized by the hanging-drop method of vapour diffusion complexed with the disaccharide mannose-alpha1,6-D-mannose. The crystals are in the space group P21212 with unit-cell dimensions a = 70.63, b = 92.79 and c = 47.25 A, and with a dimer in the asymmetric unit. The crystals diffract X-rays to beyond 1.5 A resolution at 277 K and are stable in an X-ray beam. Data to 1.6 A resolution have been collected using a MAR image-plate system at a synchrotron source and the structure of the complex has been solved by the molecular replacement method.
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Affiliation(s)
- L M Wright
- School of Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, England.
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Wright LM, Wood SD, Reynolds CD, Rizkallah PJ, Van Damme EJ, Peumans WJ. Crystallization and preliminary X-ray analysis of a novel plant lectin from Calystegia sepium. Acta Crystallogr D Biol Crystallogr 1997; 53:220-1. [PMID: 15299962 DOI: 10.1107/s0907444996010955] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A mannose-specific lectin from Calystegia sepium has been crystallized by the hanging-drop vapour-diffusion method using ammonium sulfate as precipitant. The needle-shaped crystals are orthorhombic, space group C222(1) with cell dimensions a = 55.2(1), b = 55.9 (1), c = 196.1 (1) A. Fresh crystals diffract to 1.9 A resolution on a synchrotron radiation source. The asymmetric unit contains a dimer of two identical 16 kDa subunits with a packing density of 2.36 A(3) Da(-1). Intensity data have been observed beyond 2.0 A, but reasonable statistics restricted the usable range to 2.0 A.
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Affiliation(s)
- L M Wright
- School of Biomolecular Sciences, Liverpool John Moores University, England.
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Chantalat L, Wood SD, Rizkallah P, Reynolds CD. X-ray Structure Solution of Amaryllis Lectin by Molecular Replacement With Only 4% of the Total Diffracting Matter. Acta Crystallogr D Biol Crystallogr 1996; 52:1146-52. [PMID: 15299575 DOI: 10.1107/s090744499600546x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
It is often the case that analogous proteins from different species crystallize in a different form. These structures can usually be easily solved by the molecular-replacement (MR) technique, as the protein folding is very often conserved. However, the results from MR become more uncertain as the proportion of diffracting matter decreases as a result of multimericity and/or absence of some of the atoms in the model. In this paper results are presented on the structure solution of amaryllis lectin (109 residues per monomer) containing two protein molecules in the asymmetric unit. The structure was solved by MR using the Calpha coordinates of one monomer from snowdrop lectin which has 85% amino-acid sequence identity to amaryllis lectin. This represents only 6% of the non-H atoms of the protein molecule to be used for structure determination and it is a major improvement on previous reports. Further calculations were carried out in order to establish the minimum number of atoms which could be included in the model before a clear solution to the MR problem was revealed. This study showed that the structure of amaryllis lectin could still have been solved easily with 3.85% of the model, which even in the most favourable cases, will probably constitute a minimum for molecular-replacement structure solution.
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Affiliation(s)
- L Chantalat
- Biophysics Department, School of Biomolecular Sciences, Liverpool John Moores University, England
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Rizkallah PJ, Reynolds CD, Wood SD, Wright LM, Kelly R, Lei PW, Loris R, Allen AK. Sugar in your garden/diet: lectin/sugar complexes. Acta Crystallogr A 1996. [DOI: 10.1107/s0108767396091568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Wood SD, Reynolds CD, Lambert S, McMichael PA, Allen AK, Rizkallah PJ. Crystallization and preliminary X-ray studies on the mannose-specific lectin from Amaryllis bulbs. Acta Crystallogr D Biol Crystallogr 1994; 50:110-1. [PMID: 15299484 DOI: 10.1107/s0907444993009564] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Affinity-purified amaryllis lectin was used to grow single crystals using the hanging-drop method. The space group was found to be C2 with unit-cell dimensions a = 73.4 (1), b = 100.3 (1), c = 62.2 (1) A and beta = 137.3 (2) degrees. Data to 2.25 A resolution have been recorded and solution of the structure is currently underway by means of molecular-replacement techniques.
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Affiliation(s)
- S D Wood
- School of Biomolecular Sciences, Liverpool John Moores University, England
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Reynolds CD, Rhinehart E, Dreyer P, Goldmann DA. Variability in reprocessing policies and procedures for flexible fiberoptic endoscopes in Massachusetts hospitals. Am J Infect Control 1992; 20:283-90. [PMID: 1492692 DOI: 10.1016/s0196-6553(05)80231-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND Concern is increasing regarding the risk of transmission of blood-borne pathogens by means of improperly reprocessed medical devices. METHODS On-site surveys of policies and practices were performed in 18 reprocessing areas in eight randomly selected hospitals in Massachusetts to assess current practices for reprocessing of flexible fiberoptic endoscopes. Manufacturers' and internal written protocols, were reviewed, employees were interviewed, and procedures were observed. Reprocessing included high-level disinfection in 17 of 18 areas, with 16 areas using 2% glutaraldehyde; ethylene oxide gas sterilization was used in one area. RESULTS Considerable interhospital and intrahospital variability was found in high-level disinfection procedures, including equipment, contact time (range 10 to 45 minutes), disinfectant testing, and rinsing. Disinfection of internal channels was inadequate in three areas, recommended sterilization of biopsy forceps was not performed in five, and written protocols were unavailable in three. Ad hoc deviation from established written or verbal protocols occurred in eight areas during reprocessing of flexible fiberoptic endoscopes from patients known to have AIDS; ethylene oxide sterilization was used in seven areas and a separate device was used in one. Interviews with personnel revealed that lack of knowledge of high-level disinfection contributed to the discrepancies between policy and practice. CONCLUSIONS We conclude that reprocessing of flexible fiberoptic endoscopes is inconsistent and potentially ineffective. Knowledge that a flexible fiberoptic endoscope was used for a patient with AIDS influences practice.
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Affiliation(s)
- C D Reynolds
- Division of Health Care Quality, Massachusetts Department of Public Health, Boston
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Blake AJ, Crook JR, Mawby RJ, Reid AJ, Reynolds CD. Structure of cis-dicarbonyl[2-carboxylato-1-methoxycarbonyl-2-(4-methylphenyl)vinyl]-trans-bis(dimethylphenylphosphine)ruthenium(II), a complex containing a bidentate vinyl ligand. Acta Crystallogr C 1992. [DOI: 10.1107/s010827019200057x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Badger J, Harris MR, Reynolds CD, Evans AC, Dodson EJ, Dodson GG, North AC. Structure of the pig insulin dimer in the cubic crystal. Acta Crystallogr B 1991; 47 ( Pt 1):127-36. [PMID: 2025410 DOI: 10.1107/s0108768190009570] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Atomic coordinates for pig insulin in the cubic crystal have been refined by reciprocal-space methods to an R factor of 0.173 for data between 10.0 and 1.7 A resolution with structure-factor amplitudes greater than two standard deviations. Stereochemical parameters for the refined model are close to standard values and the estimated error in the positions of well-ordered atoms is about 0.1 A. Residues directly involved in the formation of the exact (crystallographic) cubic insulin dimer are oriented similarly to those in the non-crystallographic 2Zn insulin dimer. Other residues, which make different molecular contacts in the different crystal forms, have locally altered conformations. The cubic insulin molecule is significantly more similar to one of the two independent molecules in the 2Zn insulin dimer than the other. This more similar molecule is expected to be the more stable conformer.
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Affiliation(s)
- J Badger
- Department of Physics, University of York, England
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Crook JR, Giordano F, Mawby RJ, Reid AJ, Reynolds CD. Structure of 1,1-dicarbonyl-1,1-bis(dimethylphenylphosphine)-2,3-bis(methoxycarbonyl)-1-ruthenaindene, a ruthenium(II) complex containing a five-membered metallacycle. Acta Crystallogr C 1990. [DOI: 10.1107/s0108270189005597] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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19
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Everett JH, Reynolds CD, Sparks CA, Pangborn W, Strong P, Bailey PD, Dauter Z, Helliwell M, Hollinshead SP. Structure of dimethyl (1S,3S)-1-methoxycarbonylmethyl-1,2,3,4-tetrahydro-9H-pyrido[3,4-b]indole-1,3-dicarboxylate at 165 K. Acta Crystallogr C 1989. [DOI: 10.1107/s0108270189004166] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Derewenda U, Derewenda Z, Dodson EJ, Dodson GG, Reynolds CD, Smith GD, Sparks C, Swenson D. Phenol stabilizes more helix in a new symmetrical zinc insulin hexamer. Nature 1989; 338:594-6. [PMID: 2648161 DOI: 10.1038/338594a0] [Citation(s) in RCA: 230] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
SINCE insulin was first shown by Scott to crystallize in the presence of zinc ions in 1934, a variety of Zn-containing insulin crystals have been grown. The structures of insulin in the related rhombohedral crystals of 2Zn-insulin and 4Zn-insulin have been solved and reveal that the molecule is a hexamer, organized as three dimers, each containing a 2-fold symmetry axis and held together by Zn ions. In 2Zn-insulin the hexamer is nearly symmetrical with the two axial Zn ions and the two molecules of the dimer related closely by a local 2-fold axis. But in 4Zn-insulin the two molecules in the dimer differ remarkably, creating an asymmetric 4Zn-hexamer in which one trimer is essentially equivalent to that in 2Zn-insulin and the other is different by virtue of an additional stretch of N-terminal helix between residues B1 and B8 (refs 6, 7). We report here the structure of a new symmetrical hexamer, in which all six molecules have the B1-B8 helix seen in 4Zn-insulin. Phenol molecules, found bonding specifically to each molecule, evidently stabilize this new helical conformation.
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Reynolds CD, Stowell B, Joshi KK, Harding MM, Maginn SJ, Dodson GG. Preliminary study of a phase transformation in insulin crystals using synchrotron-radiation Laue diffraction. Acta Crystallogr B Struct Sci 1988. [DOI: 10.1107/s0108768188005956] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Acheson RM, Dauter Z, Karaulov A, Lee GCM, Reynolds CD. Structure of dibenzo[ a,g]cyclotrideca-4a,8a-diene-5,7-diyn-15-one. Acta Crystallogr C 1988. [DOI: 10.1107/s0108270188005633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Baker EN, Blundell TL, Cutfield JF, Cutfield SM, Dodson EJ, Dodson GG, Hodgkin DM, Hubbard RE, Isaacs NW, Reynolds CD. The structure of 2Zn pig insulin crystals at 1.5 A resolution. Philos Trans R Soc Lond B Biol Sci 1988; 319:369-456. [PMID: 2905485 DOI: 10.1098/rstb.1988.0058] [Citation(s) in RCA: 462] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The paper describes the arrangement of the atoms within rhombohedral crystals of 2Zn pig insulin as seen in electron density maps calculated from X-ray data extending to 1.5 A (1 A = 10(-10) m = 10(-1) nm) at room temperature and refined to R = 0.153. The unit cell contains 2 zinc ions, 6 insulin molecules and about 3 x 283 water molecules. The atoms in the protein molecules appear well defined, 7 of the 102 side chains in the asymmetric unit have been assigned alternative disordered positions. The electron density over the water molecules has been interpreted in terms of 349 sites, 217 weighted 1.0, 126 weighted 0.5, 5 at 0.33 and 1 at 0.25 giving ca. 282 molecules. The positions and contacts of all the residues belonging to the two A and B chains of the asymmetric unit are shown first and then details of their arrangement in the two insulin molecules, 1 and 2, which are different. The formation from these molecules of a compact dimer and the further aggregation of three dimers to form a hexamer around two zinc ions, follows. It appears that in the packing of the hexamers in the crystal there are conflicting influences; too-close contacts between histidine B5 residues in neighbouring hexamers are probably responsible for movements of atoms at the beginning of the A chain of one of the two molecules of the dimer that initiate movements in other parts, particularly near the end of the B chain. At every stage of the building of the protein structure, residues to chains of definite conformation, molecules, dimers, hexamers and crystals, we can trace the effect of the packing of like groups to like, aliphatic groups together, aromatic groups together, hydrogen-bonded structures, positive and negative ions. Between the protein molecules, the water is distributed in cavities and channels that are continuous throughout the crystals. More than half the water molecules appear directly hydrogen bonded to protein atoms. These are generally in contact with other water molecules in chains and rings of increasing disorder, corresponding with their movement through the crystals. Within the established crystal structure we survey next the distribution of hydrogen bonds within the protein molecules and between water and protein and water and water; all but eight of the active atoms in the protein form at least one hydrogen bond.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- E N Baker
- Department of Chemistry and Biochemistry, Massey University, Palmerston North, New Zealand
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Dauter Z, Hansen LK, Mawby RJ, Probitts EJ, Reynolds CD. Structures of two 6,6-diaryfulvene complexes of rhodium: (1,5-cyclooctadiene)(6,6-diphenylfulvene)rhodium(I) perchlorate, [Rh(C8H12)(C18H14)]ClO4, (I), and [6,6-bis(4-chlorophenyl)fulvene]bis(triphenyl phosphite)rhodium(I) perchlorate, [Rh(C18H12Cl2)(C18H15O3P)2]ClO4, (II). Acta Crystallogr C 1985. [DOI: 10.1107/s010827018500573x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Dauter Z, Greenhill JV, Karaulov A, Reynolds CD. Structure of 5,5-dimethyltricyclo[6.2.2.02,7]dodecane-3,9-dione, C14H20O2. Acta Crystallogr C 1985. [DOI: 10.1107/s0108270185004899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Bryce MR, Dauter Z, Kämpchen T, Reynolds CD, Seitz G. Structure of the twofold addition product tetramethyl 6-diethylamino-3,7a,10,11b-tetrahydro-7H-dipyridazino[4,5-b:4',5'-d]azepine-1,4,8,11-tetracarboxylate, C22H28N6O8. Acta Crystallogr C 1984. [DOI: 10.1107/s0108270184010118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Abstract
X-ray studies on human insulins prepared by semisynthetic and biosynthetic methods have recently been undertaken. Human insulin differs from porcine insulin only at the COOH terminus of the B-chain. The present study reports the crystal structure of 4-zinc human insulin, which is used clinically as a slow-acting preparation. The structure has been refined, using 1.85-A resolution data, to a residual of 0.173. The unit cell is rhombohedral, space group R3, with hexagonal cell constants a = 80.953 and c = 37.636 A, and it is nearly isomorphous with that of 4-zinc porcine insulin. As a result of a conformational change of the first eight residues of the B-chain of molecule 1 from an extended conformation observed in the 2-zinc structure to an alpha-helical one, the coordination around one of the zinc ions on the 3-fold axis has changed, an additional zinc ion in a general position is bound by the hexamer, and additional hydrogen-bonded interactions help stabilize dimer and hexamer formation. Unlike the surface of the 2-zinc insulin hexamer, which possesses a shallow depression containing a zinc ion and its coordinating water molecules, the 4-zinc human insulin hexamer contains a zinc and chloride ion at the bottom of an 8-A tunnel produced by three parallel alpha-helices. These alpha-helices shield the zinc ion from the environment, decreasing the rate of dissociation of the hexamer, and provide an explanation for the slow-acting aspect of the 4-zinc crystalline form.
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Smith GD, Swenson DC, Dodson EJ, Dodson GG, Reynolds CD. Conformational flexibility in the 4-zinc human insulin hexamer as determined by X-ray crystallography. Acta Crystallogr A 1984. [DOI: 10.1107/s0108767384098238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Dauter Z, Hanson P, Reynolds CD, Stockburn WA. Structure of (8aRS,9RS,10aSR)-10-ethoxycarbonyl-1,2,3,4,5,6,7,8,8a,10a-decahydro-10H-9-thia-10-azaphenanthrene 9-oxide, C15H23NO3S. Acta Crystallogr C 1984. [DOI: 10.1107/s0108270184004728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Chawdhury SA, Dodson EJ, Dodson GG, Reynolds CD, Tolley SP, Blundell TL, Cleasby A, Pitts JE, Tickle IJ, Wood SP. The crystal structures of three non-pancreatic human insulins. Diabetologia 1983; 25:460-4. [PMID: 6363174 DOI: 10.1007/bf00284451] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
X-ray studies on semi-synthetic human insulin have shown that it crystallizes in the rhombohedral space group R3 and is nearly isomorphous with 2 Zn pig insulin. Precession photographs of crystals of human and pig insulins show observable changes in the intensity patterns. Crystallographic analysis and refinement of semi-synthetic human insulin at 1.9 A resolution have shown that its molecular structure is very like that of pig insulin except at the C-terminus of the B chain where the change in sequence occurs. We also report the results of a high resolution crystallographic study of human insulins from different origins. The X-ray diffraction patterns of three non-pancreatic human insulins are indistinguishable from each other and from pancreatic human insulin. Refinement of the structures of the non-pancreatic human insulins has shown that they are identical within the limits of experimental error.
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Dauter Z, Mawby RJ, Reynolds CD, Saunders DR. Structure of (tert-butyl isocyanide)carbonyl(chloro)bis[dimethyl(phenyl)phosphine]phenylruthenium(II), [Ru(C6H5)(C5H9N)(C8H11P)2(CO)Cl]. Acta Crystallogr C 1983. [DOI: 10.1107/s0108270183007891] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Chawdhury SA, Dauter Z, Mawby RJ, Reynolds CD, Saunders DR, Stephenson M. Structure of benzoyl(tert-butyl isocyanide)(carbonyl)bis(dimethylphenylphosphine)(phenyl)ruthenium(II), C35H41NO2P2Ru. Acta Crystallogr C 1983. [DOI: 10.1107/s010827018300709x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Ru-chang B, Cutfield SM, Dodson EJ, Dodson GG, Giordano F, Reynolds CD, Tolley SP. Molecular-replacement studies on crystal forms of despentapeptide insulin. Acta Crystallogr B Struct Sci 1983. [DOI: 10.1107/s0108768183002062] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Dodson EJ, Dodson GG, Reynolds CD. Fast Fourier refinement of the structure of hagfish insulin at 1.9 Å resolution. Acta Crystallogr A 1981. [DOI: 10.1107/s0108767381099145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Abstract
The refinement of the crystal structure of two-Zn pig insulin using 1.5-A (1A = 0.1 nm) resolution data by Fourier and fast Fourier least-squares methods allows us to make detailed comparisons between the two independent molecules present in the two-Zn insulin dimer and to describe their interactions in the monomer, dimer, and hexamer. The main chain structures for the two molecules agree well except at the N terminus of the A chain and the C terminus of the B chain. The residues along the line of the local two-fold axes, apart from the B25 side chain, conform extremely closely to the two-fold symmetry, although the discrepancies are much more apparent away from this axis. The ability of the insulin molecule to adopt different conformations may be an important factor in the expression of its biological activity.
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Cartwright BA, Reynolds CD, Skapski AC. Interaction of metal ions with pyrimidine derivatives: X-ray crystal structure of tetrakis(2-pyrimidinone)copper(II) perchlorate–ethanol. ACTA ACUST UNITED AC 1977. [DOI: 10.1107/s0567740877007250] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Reynolds CD, Palmer RA. The crystal structure, absolute configuration and stereochemistry of (+)-tubocurarine dibromide methanol solvate: a potent neuromuscular blocking agent. ACTA ACUST UNITED AC 1976. [DOI: 10.1107/s0567740876005517] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Goodgame DM, Jeeves I, Reynolds CD, Skapski AC. Heavy metal-pyrimidine nucleotide interaction: x-ray structure of a cadmium derivative of cytidine 5'-monophosphate. Biochem J 1975; 151:467-8. [PMID: 1218087 PMCID: PMC1172383 DOI: 10.1042/bj1510467] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
An X-ray crystal-structure determination has shown that the compound [Cd(5'-CMP)(H2O)],H2O has a polymeric structure in which each cadmium atom is bonded to five atoms: to the N(3) position on the base, to a phosphate oxygen from each of three other 5'-CMP groups and to a water molecule.
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Abstract
X-ray structure determination of the compound (C37H42N2O6)2+ .2Br-.4CH3OH, confirms that (+)-tubocurarine is a monoquaternary salt and has established that the molecule adopts different conformations in crystals of the dibromide and dichloride salts. The crystal structure is stabilised by a number of hydrogen bonds involving the two free hydroxyl groups and the tertiary nitrogen of the tubocurarine molecule, the bromide ions and the solvent molecules. The absolute configuration of the molecule, determined by X-ray anomalous scattering, confirms the configuration assigned earlier by chemical studies.
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Goodgame DM, Jeeves I, Reynolds CD, Skapski AC. Multiplicity of cadmium binding sites in nucleotides: X-ray evidence for the involvement of O2' and O3' as well as phosphate and N7 in inosine 5'-monophosphate. Nucleic Acids Res 1975; 2:1375-9. [PMID: 1178522 PMCID: PMC344388 DOI: 10.1093/nar/2.8.1375] [Citation(s) in RCA: 39] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Single-crystal X-ray methods have been used to characterize a hydrated polymeric cadmium derivative of inosine 5'-monophosphate. In the structure there are two independent cadmium atoms, one of which binds to two ribose oxygen atoms, an N7 position on a base, and to three water molecules. The second metal atom binds to a phosphate oxygen, three water molecules, and to two N7 atoms, which are in cis-positions. For these last; the Cd-N bonds are appreciably out of the planes of the hypoxanthine bases so that the angle between these planes is only 31.4 degrees.
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