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Biomedical subjects

I Rayment

Publications and source records attributed to I Rayment.

102 records · Page 6Linked to original sources
PubMed1986

Crystallization of a high potential iron-sulfur protein from the halophilic phototrophic bacterium Ectothiorhodospira halophila.

Crystals of the high-potential iron-sulfur protein from Ectothiorhodospira halophila strain BN 9626 have been grown from 3.4 to 3.5 M ammonium sulfate solutions at pH 7.5. The crystals belong to the space group P21 with unit cell dimensions of a = 60.00 A, b = 31.94 A, c = 40.27 A, and beta = 100.5 degrees. There are 2 molecules/asymmetric unit. The crystals diffract to at least 1.8 A, are stable in the x-ray beam, and are suitable for a high resolution x-ray crystallographic analysis.

Chromatiaceae↗
PubMed1986

Crystallization of insecticyanin from the hemolymph of the tobacco hornworm Manduca sexta L. in a form suitable for a high resolution structure determination.

Insecticyanin, a blue biliprotein from the tobacco hornworm Manduca sexta, has been crystallized in a form suitable for a high resolution x-ray analysis. The crystals grow by vapor diffusion against solutions of polyethylene glycol 8000 at pH 5.5. They belong to the space group P4(1)2(1)2 or P4(3)2(1)2 with unit cell dimensions of a = b = 115.0 A; c = 71.1 A. Insecticyanin is believed to be a tetramer in solution; there are two subunits per asymmetric unit. The crystals diffract to at least 2.2 A resolution and appear reasonably resistant to radiation damage.

Animals↗
PubMed1986

Crystallization and preliminary analysis of crystals of high potential iron-sulfur protein from Rhodospirillum tenue.

Large single crystals of the high potential iron-sulfur protein isolated from Rhodospirillum tenue strain 3761 have been obtained. They belong to the space group P2(1) with unit cell dimensions of a = 36.7 A, b = 52.6 A, c = 27.6 A, and beta = 90.8 degrees. There are two molecules in the asymmetric unit. Based on oscillation photographs, the crystals diffract to at least 1.6 A resolution. They are stable in the x-ray beam and appear suitable for a high resolution x-ray structure analysis.

Crystallization↗
PubMed1985

Packing analysis of crystalline myosin subfragment-1. Implications for the size and shape of the myosin head.

Crystals of myosin subfragment-1 have been examined by X-ray diffraction and electron microscopy to determine how the molecules pack in the unit cell and to gain preliminary information on the size and shape of the myosin head. Subfragment-1 crystallizes in space group P212121. Analysis of the X-ray diffraction photographs shows that there are eight molecules in the unit cell with two in the asymmetric unit related by a non-crystallographic or local 2-fold axis. It also indicates that in projection down the a axis, two molecules of myosin subfragment-1 lie almost directly on top of one another except for a translation of about 9 A along c. Small crystals were fixed and embedded in the presence of tannic acid, and thin sections were cut perpendicular to each of the three crystallographic axes. Image analysis of micrographs recorded from these sections confirm the packing arrangement deduced from X-ray diffraction, and give the approximate size and shape of the molecule in the crystal lattice. They show that the molecule is at least 160 A long with a maximum thickness of about 60 A, and that it has marked curvature in the unit cell.

Animals↗
PubMed1984

Crystallization of myosin subfragment 1.

Crystals of myosin subfragment 1 from avian skeletal muscle have been grown reproducibly. They diffract x-rays to at least 4.5-A resolution. The subfragment 1 crystallizes in space group P2(1)2(1)2(1) where a = 107 A, b = 117 A, and c = 278 A. The cell dimensions and intensity distribution on x-ray diffraction photographs are consistent with two molecules in the crystallographic asymmetric unit. Electrophoretic analysis shows that the myosin subfragment 1 present in the crystals contains a 95-kilodalton heavy chain fragment and both the essential and regulatory light chains.

Actins↗
PubMed1982

Polyoma virus capsid structure at 22.5 A resolution.

X-ray diffraction data from polyoma capsid crystals were phased by refinement of low-resolution starting models to obtain a self-consistent structural solution. The unexpected result that the hexavalent morphological unit is a pentamer shows that specificity of bonding is not conserved among the protein subunits in the icosahedrally symmetric capsid.

Capsid↗
PubMed1979

Metal-free southern bean mosaic virus crystals.

Native southern bean mosaic virus contains a significant number of Mg2+ and Ca2+ ions. These can be removed by treatment with EDTA causing the virus to swell by 7% in radius at alkaline pH values. The swollen virions are susceptible to protease and nuclease digestion. They are likely to be an intermediate during assembly and disassembly. Crystals of the metal-free virus have been grown and were found to be approximately isomorphous with the orthorhombic type III southern bean mosaic virus crystals (Akimoto, T., Wagner, M.A., Johnson, J.E., and Rossmann, M.G. (1975) J. Ultrastruct. Res. 53, 306-318), although the cell dimensions are longer by 2%. Native rhombohedral type II crystals disintegrate on changing the pH or increasing the ionic strength of the mother liquor. Damage can be prevented by addition of ethylene glycol. At alkaline pH values, these crystals also show a 2% increase in their cell dimensions as well as a significant alteration in their diffraction patterns. In the type II and III crystals, the viruses pack with only their 5-fold axes in contact. Thus, the difference of the apparent swelling in solution and in the crystals may be one of differential swelling over the virus surface.

Calcium↗