Single crystal EPR studies of paramagnetic ions doped zinc potassium phosphate hexahydrate

A β-1,3-glucanase from the thermophilic fungusChaetomium thermophilumwas overexpressed inPichia pastoris, purified and crystallized in the presence of 1.8 Msodium/potassium phosphate pH 6.8 as a precipitant. Data to 2.0 Å resolution were collected in-house at 293 K from a single crystal. The crystal was found to belong to space groupP21, with unit-cell parametersa= 64.1,b= 85.8,c= 68.5 Å, β = 93.1° and one molecule in the asymmetric unit.

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Single crystal EPR investigation on Mn(II) doped biomineral: cobalt potassium phosphate hexahydrate

Journal of Physics and Chemistry of Solids ◽

10.1016/j.jpcs.2004.10.011 ◽

2005 ◽

Vol 66 (5) ◽

pp. 876-881 ◽

Cited By ~ 6

Author(s):

K. Velavan ◽

R. Venkatesan ◽

P. Sambasiva Rao

Keyword(s):

Single Crystal ◽

Potassium Phosphate

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A Preparation of High Resolution Standards for Electron Microscopy. Part II

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100064852 ◽

1971 ◽

Vol 29 ◽

pp. 160-161

Author(s):

Akira Tanaka ◽

David F. Harling

Keyword(s):

Electron Microscopy ◽

High Resolution ◽

Carbon Black ◽

Single Crystal ◽

Dark Field ◽

Graphitized Carbon Black ◽

Graphitized Carbon ◽

Dark Field Imaging ◽

Crystal Films ◽

Micro Holes

In the previous paper, the author reported on a technique for preparing vapor-deposited single crystal films as high resolution standards for electron microscopy. The present paper is intended to describe the preparation of several high resolution standards for dark field microscopy and also to mention some results obtained from these studies. Three preparations were used initially: 1.) Graphitized carbon black, 2.) Epitaxially grown particles of different metals prepared by vapor deposition, and 3.) Particles grown epitaxially on the edge of micro-holes formed in a gold single crystal film.The authors successfully obtained dark field micrographs demonstrating the 3.4Å lattice spacing of graphitized carbon black and the Au single crystal (111) lattice of 2.35Å. The latter spacing is especially suitable for dark field imaging because of its preparation, as in 3.), above. After the deposited film of Au (001) orientation is prepared at 400°C the substrate temperature is raised, resulting in the formation of many square micro-holes caused by partial evaporation of the Au film.

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Ultrastructure of Melanin Formation in Curvularia sp., Alternaria sp., and Drechslera Sorokiniana

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100079449 ◽

1977 ◽

Vol 35 ◽

pp. 398-399

Author(s):

M. H. Wheeler ◽

W. J. Tolmsoff ◽

A. A. Bell

Keyword(s):

Potassium Phosphate ◽

Thielaviopsis Basicola ◽

Wild Type ◽

Potassium Phosphate Buffer ◽

Transmission Microscopy ◽

Electron Transmission ◽

Melanin Formation ◽

Before And After ◽

Alternaria Sp ◽

Electron Transmission Microscopy

(+)-Scytalone [3,4-dihydro-3,6,8-trihydroxy-l-(2Hj-naphthalenone] and 1,8-di- hydroxynaphthalene (DHN) have been proposed as intermediates of melanin synthesis in the fungi Verticillium dahliae (1, 2, 3, 4) and Thielaviopsis basicola (4, 5). Scytalone is enzymatically dehydrated by V. dahliae to 1,3,8-trihydroxynaphthalene which is then reduced to (-)-vermelone [(-)-3,4- dihydro-3,8-dihydroxy-1(2H)-naphthalenone]. Vermelone is subsequently dehydrated to DHN which is enzymatically polymerized to melanin.Melanin formation in Curvularia sp., Alternaria sp., and Drechslera soro- kiniana was examined by light and electron-transmission microscopy. Wild-type isolates of each fungus were compared with albino mutants before and after treatment with 1 mM scytalone or 0.1 mM DHN in 50 mM potassium phosphate buffer, pH 7.0. Both chemicals were converted to dark pigments in the walls of hyphae and conidia of the albino mutants. The darkened cells were similar in appearance to corresponding cells of the wild types under the light microscope.

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