Structure of an insulin dimer in an orthorhombic crystal: the structure analysis of a human insulin mutant (B9 Ser→Glu)

1999 ◽  
Vol 55 (9) ◽  
pp. 1524-1532 ◽  
Author(s):  
Zhi-Ping Yao ◽  
Zong-Hao Zeng ◽  
Hong-Min Li ◽  
Ying Zhang ◽  
You-Min Feng ◽  
...  
Keyword(s):  
Human Insulin ◽  
Solution Structure ◽  
Building Blocks ◽  
Structural Rearrangement ◽  
Crystal Form ◽  
Terminal Segment ◽  
Orthorhombic Crystal ◽  
Amino Terminal ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

The structure of human insulin mutant B9 (Ser→Glu) was determined by an X-ray crystallographic method at 2.5 Å resolution with an R factor of 0.165 under non-crystallographic restraints. The crystals were grown at low pH (<3.8) and belong to the orthorhombic P212121 space group with unit-cell dimensions a = 44.54, b = 46.40, c = 51.85 Å and one dimer per asymmetric unit without further aggregation. The structure in this crystal form can be regarded as a model for a discrete insulin dimer and displays the following features compared with the structure of 2Zn insulin. (i) The overall dimer is expanded and more symmetric. The two A chains are about 2 Å more distant from each other, while the two B chains are about 0.8 Å further apart. Both monomers are more similar to molecule 1 than molecule 2 of the 2Zn insulin dimer. (ii) The dimer structure is stabilized by protonation and neutralization of the carboxyl groups at lower pH and, in addition, by formation of a hydrogen-bond network among the side chains of residues GluB9, HisB13 and HisB10 on the dimer-forming surface of both monomers, resulting from a structural rearrangement. (iii) The B-chain amino-terminal segment is in an open state (O state), i.e. a state different from the well known R and T states found in the insulin hexamer. In the O state, the B-chain N-terminal segment is in an extended conformation and is detached from the rest of the molecule. This conformational state has also been observed in the monomeric crystal structure of despentapeptide (B26–B30) and desheptapeptide (B24–B30) insulin, as well as in the solution structure of an engineered insulin monomer. It suggests that the O state may be the characteristic conformation of insulin in lower aggregation forms and may be relevant to the formation of insulin fibrils. In addition, based on the crystallization process, the smallest possible building blocks of insulin crystal are also discussed.

Crystallization and preliminary X-ray crystallographic analysis of the Pseudomonas aeruginosa cyclohexadienyl dehydratase

1999 ◽  
Vol 55 (2) ◽  
pp. 539-541
Author(s):  
Palangpon Kongsaeree ◽  
Jun Liang ◽  
Roy A. Jensen ◽  
Jon Clardy
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Crystal Form ◽  
High Energy ◽  
Crystallographic Analysis ◽  
Unit Cell ◽  
Space Group ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

The title protein has been crystallized in a new crystal form. The crystals belong to the cubic space group P4132 (or P4332) with unit-cell dimensions a = b = c = 126.1 Å at 100 K and typically diffract beyond 1.6 Å at the Cornell High Energy Synchotron Source (CHESS) A1 beamline.

Direct observation of deuterium migration in crystalline-state reaction by single-crystal neutron diffraction. III. Photoracemization of 1-cyanoethyl cobaloxime complexes

2001 ◽  
Vol 57 (4) ◽  
pp. 551-559 ◽  
Author(s):  
Takashi Ohhara ◽  
Hidehiro Uekusa ◽  
Yuji Ohashi ◽  
Ichiro Tanaka ◽  
Shintaro Kumazawa ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Single Crystal ◽  
Bond Cleavage ◽  
Cobalt Complexes ◽  
Crystal Form ◽  
Xenon Lamp ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Stereogenic Center ◽  
Cyanoethyl Group

The H atoms bonded to the chiral C atoms (stereogenic center) of the 1-cyanoethyl groups in two cobalt complexes, [(R)-1-cyanoethyl]bis(dimethylglyoximato)(pyridine)cobalt(III) (2) and [(R,S)-1-cyanoethyl]bis(dimethylglyoximato)(piperidine)cobalt(III) (3), were replaced with D atoms, such as Co—C*D(CH3)CN. The crystals of the two cobalt complexes were irradiated with a xenon lamp for 72 h and 27 d, respectively. The unit-cell dimensions were gradually changed with retention of the single-crystal form. The crystal structures after irradiation were determined by neutron diffraction. In each crystal the chiral 1-cyanoethyl group of one of the two crystallographically independent molecules was partly inverted to the opposite configuration, whereas that of the other molecule kept the original configuration. The C*—D bond in the inverted group was completely conserved in the process of the inversion of the chiral alkyl group. This suggests that the inversion of the chiral 1-cyanoethyl group proceeds with the rotation of the cyanoethyl radical after the Co—C bond cleavage by photo-irradiation so that the opposite side of the radical faces the Co atom. This is followed by recombination of the Co—C bond to form the inverted 1-cyanoethyl group.

Synthesis and Structural Characterization of a New Two-dimensional Organic-Inorganic Hybrid Molybdoarsenate: [Cu(en)2]2[(CuO6)Mo6O18(As3O3)2]

2010 ◽  
Vol 65 (2) ◽  
pp. 163-167 ◽  
Author(s):  
Qiang Wu ◽  
Qiuxia Han ◽  
Lijun Chen ◽  
Pengtao Ma ◽  
Jingyang Niu
Keyword(s):  
Thermogravimetric Analysis ◽  
Building Blocks ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Inorganic Hybrid ◽  
X Ray ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
2D Network

A new organic-inorganic hybrid molybdoarsenate constructed from a unit with two (As3O3) rings capping Anderson-type moieties, [Cu(en)2]2[(CuO6)Mo6O18(As3O3)2] (1) (en = ethylenediamine), has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction and thermogravimetric analysis. The compound crystallizes monoclinically, space group P21/c, with unit cell dimensions a = 9.1541(7), b = 19.6348(14), c = 14.5205(8) Å ,β = 129.082(3)◦,V = 364.20(4) Å3, Z = 2, T = 296(2) K. Complex 1 represents the first example of a 2D network of a POM polymer where [(CuO6)Mo6O18(As3O3)2]4− building blocks are connected by complex fragments {Cu(en)2}2+.

Preliminary X-ray analysis of a new crystal form of recombinant pig kidney DOPA decarboxylase

1999 ◽  
Vol 55 (2) ◽  
pp. 568-570 ◽  
Author(s):  
V. N. Malashkevich ◽  
P. Burkhard ◽  
P. Dominici ◽  
P. S. Moore ◽  
C. Borri Voltattorni ◽  
...  
Keyword(s):  
Heavy Atom ◽  
Crystal Form ◽  
Dopa Decarboxylase ◽  
Data Sets ◽  
Synchrotron Source ◽  
Pig Kidney ◽  
Protein Dimers ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

DOPA decarboxylase is responsible for the synthesis of the key neurotransmitters dopamine and serotonin via decarboxylation of L-3,4-dihydroxyphenylalanine (L-DOPA) and L-5-hydroxytryptophan, respectively. The crystals of recombinant DOPA decarboxylase differ from those previously reported for the enzyme purified from pig kidney. They belong to space group P622 with unit-cell dimensions a = b = 302.6, c = 178.1 Å. Both the self-rotation function and the good diffraction quality of these crystals (2.5 Å on a synchrotron source) suggest that there should be at least three protein dimers in the asymmetric unit. Diffraction data sets have been collected for the native enzyme and a heavy-atom derivative.

scholarly journals The structure of bovine β-lactoglobulin in crystals grown at pH 3.8 exhibiting novel threefold twinning

2019 ◽  
Vol 75 (10) ◽  
pp. 640-645 ◽  
Author(s):  
Todd O. Yeates ◽  
Alexander McPherson
Keyword(s):  
Sodium Citrate ◽  
Crystal Form ◽  
Edge Length ◽  
Molecular Replacement ◽  
X Ray Diffraction ◽  
Acceptable Solution ◽  
Space Group ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Β Lactoglobulin

Bovine β-lactoglobulin was crystallized from 3 M NaCl buffered at pH 3.8 with sodium citrate as thick hexagonal prisms of greater than 1 mm in edge length. Analyses of the X-ray diffraction intensities using three different current algorithms were unanimous in specifying the space group to be P6322, with unit-cell dimensions a = b = 75.47, c = 140.79 Å. No progress could be made, however, towards an acceptable solution by molecular replacement using this symmetry. In the end, it was found that the true space group was C2221, a subgroup of P6322, with a = 65.89, b = 114.12, c = 140.51 Å, with the apparent 622 symmetry arising from an unusual threefold or tritohedral twinning. An assembly based on a model of the protein in another crystal form (PDB entry 1beb) containing three molecules in the asymmetric unit was refined to 2.3 Å resolution with a final R factor of 0.23 and R free of 0.26. NCS restraints were maintained throughout. For the most part, the molecules found in this crystal form are virtually the same as in PDB entry 1beb, although there are numerous local variations, particularly in loop elements, rotamer conformation differences and some alterations, including additions, at the termini.

Preliminary X-ray analysis of a new crystal form of the vanadium-dependent bromoperoxidase from Corallina officinalis

1998 ◽  
Vol 54 (3) ◽  
pp. 454-457 ◽  
Author(s):  
Amanda A. Brindley ◽  
Andrew R. Dalby ◽  
Michail N. Isupov ◽  
Jennifer A. Littlechild
Keyword(s):  
Heavy Atom ◽  
Crystal Form ◽  
Dihydrogen Phosphate ◽  
Data Set ◽  
X Ray ◽  
Heavy Atoms ◽  
Corallina Officinalis ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Rotation Function

A new crystal form of the vanadium-dependent bromoperoxidase from Corallina officinalis has been obtained. The crystals exhibit a `teardrop' morphology and are grown from 2 M ammonium dihydrogen phosphate pH 5 and diffract to beyond 1.7 Å resolution. They are in tetragonal space group P4222 with unit-cell dimensions of a = b = 201.9, c = 178.19 Å, α = β = γ = 90°. A 2.3 Å resolution native data set has been collected at the Hamburg Synchrotron. A mercury derivative data set has also been collected, and the heavy-atom positions have been determined. The self-rotation function and the positions of the heavy atoms are consistent with the molecule being a dodecamer with local 23 symmetry.

Crystallization and preliminary X-ray analysis of thiaminase I from Bacillus thiaminolyticus: space group change upon freezing of crystals

1998 ◽  
Vol 54 (3) ◽  
pp. 448-450 ◽  
Author(s):  
Nino Campobasso ◽  
Jakob Begun ◽  
Colleen A. Costello ◽  
Tadhg P. Begley ◽  
Steven E. Ealick
Keyword(s):  
Sodium Acetate ◽  
Crystal Form ◽  
Unit Cell ◽  
Diffusion Method ◽  
Crystal Forms ◽  
Space Group ◽  
X Ray ◽  
Cell Dimensions ◽  
Thiaminase I ◽  
Unit Cell Dimensions

Thiaminase I (Mr = 42 100) from B. thiaminolyticus, expressed in E. coli, has been crystallized by the vapor-diffusion method. Three crystal forms, two of which grew from 0.1 M sodium acetate (pH = 4.6), 0.2 M ammonium sulfate and 30%(w/v) PEG 2000, have been examined by X-ray analysis. One crystal form diffracted to 2.5 Å at room temperature, was orthorhombic, and had unit-cell edges of a = 87.7, b = 120.5 and c = 76.7 Å with space group P212121. A self-Patterson map showed a strong peak indicating noncrystallographic translational pseudosymmetry with (u, v, w) = (0.03, 0.0, 0.5). When these crystals were frozen at liquid-nitrogen temperatures, a second crystal form was observed which had unit-cell dimensions a = 85.5, b = 117.5 and c = 36.6 Å with space group P21212. A third crystal form grew from 0.1 M Tris (pH = 8.5), 0.2 M sodium acetate trihydrate and 28%(w/v) PEG 6000 to produce orthorhombic crystals of space group P212121 with cell edges of a = 114.4, b = 123.1 and c = 92.5 Å.

Purification, crystallization and preliminary X-ray analysis of Drosophila melanogaster ferrochelatase

1999 ◽  
Vol 55 (6) ◽  
pp. 1201-1203 ◽  
Author(s):  
Kai-Fen Wang ◽  
Chia-Kuei Wu ◽  
Vera M. Sellers ◽  
John P. Rose ◽  
Bi-Cheng Wang ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Biosynthetic Pathway ◽  
Protoporphyrin Ix ◽  
Asymmetric Unit ◽  
Inner Mitochondrial Membrane ◽  
X Ray ◽  
Amino Terminal ◽  
Highly Sensitive ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

Ferrochelatase (protoheme ferrolyase, E.C. 4.99.1.1), the terminal enzyme in the heme biosynthetic pathway, catalyzes the insertion of ferrous iron into protoporphyrin IX to form protoheme. In eukaryotes, the protein is associated with the inner surface of the inner mitochondrial membrane, and in higher animals the enzyme contains a [2Fe–2S] cluster. This cluster is highly sensitive to NO and is coordinated by four Cys residues whose spacing in the primary sequence is unique. Ferrochelatase from Drosophila melanogaster has been expressed in Escherichia coli with an amino-terminal six-histidine tag and purified to homogeneity. The protein has been crystallized with the [2Fe–2S] cluster intact. The crystals belong to space group I422, with unit-cell dimensions a = b = 158.1, c = 171.2 Å and two molecules in the asymmetric unit, and diffract to 3.0 Å resolution.

Synthesis and Characterization of La2CaCu3O7 Compound

1998 ◽  
Vol 12 (04) ◽  
pp. 143-146
Author(s):  
K. Jeyabalan ◽  
L. K. Kaliyaperumal ◽  
A. Sekar ◽  
S. Arumugam ◽  
J. Srinivas
Keyword(s):  
Diffraction Analysis ◽  
Powder Diffraction ◽  
Synthesis And Characterization ◽  
Orthorhombic Crystal System ◽  
Orthorhombic Crystal ◽  
X Ray ◽  
Crystal System ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

Synthesis and characterization of the compound La 2 CaCu 3 O 7 has been reported here. The X-ray powder diffraction analysis reveals that the compound crystallizes in an orthorhombic crystal system with unit cell dimensions of a=5.496(6) Å, b=5.685(5) Å and c=24.356(11) Å.

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