Preliminary crystallographic studies on human apo-lactoferrin in its native and deglycosylated forms

Human apo-lactoferrin in both native and deglycosylated forms has been purified, and crystals obtained by dialysis against low ionic strength buffer solutions. The crystals of native apo-lactoferrin are orthorhombic, space group P2(1)2(1)2(1) with cell dimensions a = 222.0 A, b = 115.6 A, c = 77.8 A and have two protein molecules per asymmetric unit. Two crystal forms of deglycosylated apo-lactoferrin have been obtained. One is orthorhombic, space group P2(1)2(1)2(1), with cell dimensions a = 152.1 A, b = 94.6 A, c = 55.8 A. The second is tetragonal, space group I4, with cell dimensions a = b = 189.4 A, c = 55.1 A. Both of the latter have only one molecule per asymmetric unit, and are suitable for high-resolution X-ray structure analysis.     

Crystallization of mouse pancreatic ribonuclease

Mouse pancreatic ribonuclease has been crystallized in a form suitable for X-ray structure determination. The crystals grown from solutions of 2-methyl-2,4-pentanediol diffract to high resolution and belong to the hexagonal space group P6(1) (P6(5)) with unit cells dimensions a = b = 64.44 A, c = 53.91 A, y = 120 degrees and V = 1.94 x 10(5) A3 (1 A = 0.1 nm). There are six molecules per unit cell (1 molecule/asymmetric unit), and Vm = 2.3 A3/dalton.     

Crystallization and preliminary X-ray studies on human epidermal growth factor

Single crystals of human epidermal growth factor have been prepared from a polyethylene glycol solution and characterized by X-ray diffraction. The crystals grow in a space group of P2(1) with unit cell dimensions of a = 32.7, b = 32.5, c = 22.3 A, and beta = 96.9 degrees. They contain a single molecule per asymmetric unit and show better diffraction than 2.5 A.     

Crystallization and preliminary analysis of crystals of cytochrome c2 from Rhodopseudomonas capsulata

Two crystal forms of the cytochrome c2 isolated from Rhodopseudomonas capsulata have been obtained. One crystal form (type I), grown from ammonium sulfate solutions at pH 7.5, belongs to the space group R32 with unit cell dimensions of a = b = 100.0 A, and c = 162.2 A in the hexagonal setting. These crystals most likely contain two molecules in the asymmetric unit. The other crystal form (type II) was obtained from polyethylene glycol 6000 solutions at pH 6.5. Type II crystals belong to the space group P3(1)21 or P3(2)21 with one molecule per asymmetric unit and unit cell dimensions of a = b = 52.4 A, and c = 87.9 A. Both crystal forms diffract to at least 1.8 A resolution and appear to be resistant to radiation damage.     

Crystallization and preliminary X-ray crystallographic study of the quinoprotein methanol dehydrogenase from bacterium W3A1

Methanol dehydrogenase from bacterium W3A1 has been crystallized by the macroseeding method to give single crystals suitable for three-dimensional structural study at resolution greater than 3 A. The crystals belong to the group P2(1), and have unit cell dimensions a = 124.13 A, b = 62.87 A, c = 84.71 A, and beta = 92.89 degrees. There is one dimeric molecule of 114,600 Da per asymmetric unit.     

A new crystal form of the complex between seryl-tRNA synthetase and tRNA(Ser) from Thermus thermophilus that diffracts to 2.8 A resolution.

Two distinct complexes between seryl-tRNA synthetase and tRNA(Ser) from Thermus thermophilus have been crystallized using ammonium sulphate as a precipitant. Form III crystals grow from solutions containing a 1:2.5 stoichiometry of synthetase dimer to tRNA. They are of monoclinic space group C2 with unit cell dimensions a = 211.6 A, b = 126.8 A, c = 197.1 A, beta = 132.4 degrees and diffract to about 3.5 A. Preliminary crystallographic results show that the crystallographic asymmetric unit contains two synthetase dimers. Form IV crystals grow from solutions containing a 1:1.5 stoichiometry of synthetase dimer to tRNA. They are of orthorhombic space group P2(1)2(1)2(1) with unit cell dimensions a = 124.5 A, b = 128.9 A, c = 121.2 A and diffract to 2.8 A resolution. Preliminary crystallographic results show that these crystals contain only one tRNA molecule bound to a synthetase dimer.     

A crystallographic investigation on NADPH-adrenodoxin oxidoreductase

Single crystals of NADPH-adrenodoxin oxidoreductase were grown in 50 mM potassium phosphate (pH 7.4) containing 5% glycerol and ammonium sulfate. The crystals are monoclinic, belong to space group P21 and have dimensions of a= 83.4 A, b = 62.6 A, c = 59.3 A, alpha = gamma = 90 degrees, and beta = 107.1 degrees. There is one molecule per asymmetric unit.     

Crystallization and preliminary X-ray analysis of phosphoserine aminotransferase from Bacillus circulans subsp. alkalophilus.

Recombinant phosphoserine aminotransferase (EC 2.6.1.52) from Bacillus circulans subsp. alkalophilus was crystallized at room temperature from 0.1 M sodium acetate buffer, pH 4.6, and 2% PEG 20000, using macroseeding techniques. The crystals diffract X-rays to at least 2.0 A nominal resolution. They belong to space group C2 with unit cell dimensions a = 93.2 A, b = 93.1 A, c = 45.6 A, alpha = 90.0 degrees, beta = 106.8 degrees, gamma = 90.0 degrees. A native data set to 2.3 A has been collected. Assuming an average packing density of the crystals, there is one monomer in the asymmetric unit, resulting in a calculated solvent content of 48.2%.     

Crystallization and preliminary X-ray analysis of pig kidney DOPA decarboxylase.

DOPA decarboxylase from pig kidney, an alpha 2 dimeric enzyme of Mr = 107,000, has been crystallized by the vapour diffusion method with ammonium sulphate as precipitant. The crystals belong to the space group P6(2) (or its enantiomer P6(4)) and have unit cell dimensions of a = b = 155.9 A, c = 87.7 A, alpha = beta = 90 degrees, gamma = 120 degrees. They diffract to 2.6 A resolution. There is one dimeric molecule per asymmetric unit. Rotation function studies have revealed the orientation of the non-crystallographic 2-fold axis of the dimer in the asymmetric unit.     

Crystallization and preliminary x-ray diffraction studies of two new antigen-antibody (lysozyme-Fab) complexes

The complexes between the Fab fragments of two monoclonal anti-lysozyme antibodies, Fab10.6.6 (high affinity) and D44.2 (lower affinity), and their specific antigen, hen egg-white lysozyme, have been crystallized. The antibodies recognize an antigenic determinant including Arg68, but differ significantly in their association constants for the antigen. Two crystalline forms were obtained for the complex with FabF10.6.6, the higher affinity antibody. One of them is monoclinic, space group P21, with unit cell dimensions a = 145.6 A, b = 78.1 A, c = 63.1 A, beta = 89.05 degrees, consistent with the presence of two molecules of the complex in the asymmetric unit. These crystals diffract X-rays beyond 3 A making this form suitable for high-resolution X-ray diffraction studies. The second form crystallizes in the triclinic space group P1, with unit cell dimensions a = 134.0 A, b = 144.7 A, c = 98.6 A, alpha = 90.30 degrees, beta = 97.1 degrees, gamma = 90.20 degrees, consistent with the presence of 10 to 12 molecules of the complex in the unit cell. These crystals do not diffract X-rays beyond 5 A resolution. The antigen-antibody complex between FabD44.2, the lower affinity antibody, and hen egg-white lysozyme crystallizes in space group P2(1)2(1)2(1), with unit cell dimensions a = 99.7 A, b = 167.3 A, c = 84.7 A, consistent with the presence of two molecules of the complex in the asymmetric unit. These crystals diffract X-rays beyond 2.5 A resolution.