Proteins of the lupin family, binding molybdenum, tungsten, and radionuclide effluents from the Chernobyl Atomic Energy Station

Yellow lupine seeds were found to contain two proteins and a low molecular weight fraction possessing the ability to bind Mo, W and radionuclides from the Chernobyl nuclear power in vivo and the 185W isotope in vitro. These proteins differ in their electrophoretic mobility. The electrophoretically less mobile protein undergoes proteolytic degradation; the proteolytic product retains the ability to accumulate microelements.     

Molecular nature of the Brucella polysaccharide antigen (poly-B)

Cyclic (1----2)-beta-D-glucan was isolated from killed cells of pathogenic Brucella melitensis 16M. Its structure was deduced mainly from the acid hydrolysis, methylation analysis and 13C-NMR spectroscopy data. The cycloglucan and demicellated lipopolysaccharide of B. melitensis 16M form a stable complex identical, by immunodiffusion test, to the earlier described polysaccharide B antigen.     

Structure of the sugar-phosphate moiety of lipid A from lipooligosaccharide of Neisseria meningitidis group B,strain BC5S No. 125

On the basis of chemical and NMR data the partial structure of lipid A from lipooligosaccharide (LOS) of Neisseria meningitidis group B, strain BC₅S No 125 was established. Lipid A consisted of disaccharide 2-deoxy-6-O-[2-deoxy-2-(3-hydroxytetradecanoylamino)--gluco-pyranosyl]-2-(3-hydroxytetradecanoylamino)--glucopyranose carrying the -(2-aminoethyl)pyrophosphate residue at 0–4 and the pyrophosphate or phosphate residue at 0–1. On hydrolysis of the acidic form of LOS with 1% acetic acid the substituent at 0–1 was practically completely removed whereas that at 0–4 was stable. The analogous hydrolysis of the Mg-salt of LOS was accompanied by splitting off the pyrophosphate linkage in the substituent at 0–4. Hydrolysis of LOS at pH 4.5 in the presence of SDS led mainly to a lipid A preparation retaining both pyrophosphate residues.Abbreviations KDO 2-keto-3-deoxyoctulosonic acid - LA-I, LA-II preparations of lipid A - LOS lipooligosaccharide - LOS-H⁺ the acidic form of LOS - OS oligosaccharide - TLC thin-layer chromatography - GLC-MS gas-liquid chromatography/mass spectrometry     

Comparative x-ray diffraction study of the crystalline lens in a number of vertebrates including man

X-ray diffraction method has been applied for comparative investigation of native structure of eye lens proteins (crystallins). X-ray diffraction patterns of the whole lenses and/or their nuclear parts were obtained for man and vertebrate animals. Crystalline lenses of the fishes Acerina cernua and Pelmatochromis kribensis, frog Rana temporaria, bull and man contain crystallins with a very similar secondary and tertiary structure, whereas lenses of chicks and the tortoise Testudo horsfieldi contain mainly crystallins with other structure. The results obtained reveal evolutionary conservatism of crystallin structure in fishes, amphibians and mammals. It was also concluded that there is no correlation between crystallin structure of the lens, elasticity of the latter and accommodation mechanism.     

Bacterial antigenic polysaccharides. 12. Structure and 13C NMR spectrum of the polysaccharide chain of Shigella boydii type 8 lipopolysaccharide

A specific acidic polysaccharide was isolated from Sh. boydii type 8 antigenic lipopolysaccharide after mild hydrolysis followed by chromatography on Sephadex G-50. The polysaccharide consists of D-glucuronic acid, D-galacturonic acid, 2-acetamido-2-deoxy-D-glucose, 2-acetamido-2-deoxy-D-galactose and 2-amino-1,3-propanediol residues in 1:1:1:1:1 ratio. From the results of methylation analysis, partial acid hydrolysis and Smith degradation, the structure of the repeating unit of the specific polysaccharide was deduced as: (Formula: see text). The 13C NMR spectra of native, O-deacetylated and carboxyl-reduced polysaccharides, as well as the spectrum of oligosaccharide produced by Smith degradation were interpreted. The 13C NMR data fully confirmed the structure of the polysaccharide repeating unit.     

Role of trophic and hormonal factors in exogenous regulation of the formation of reproductive organs in yellow lupine (Lupinus luteus L.)

During the formation and ripening of beans in yellow lupine, their intactness may be increased by treatment of the plants with the microelement molybdenum or the growth factor 24-epibrassinolide. Early stages of the effects of either factor involved activation of various metabolic pathways; eventually, the supply of fruit elements with free amino acids was improved and the seed productivity of the plants, increased.     

Vanadate reduction by molybdenum-free dissimilatory nitrate reductases from vanadate-reducing bacteria

Molybdenum- and molybdenum cofactor-free nitrate reductases recently isolated by us from vanadate-reducing bacteria Pseudomonas isachenkovii are likely to mediate vanadate reduction. During anaerobic growth of P. isachenkovii on medium supplemented with nitrate and vanadate, vanadate dissimilation was followed by nitrate consumption, and this process was associated with some structural reorganizations of nitrate reductases. The homogeneous membrane-bound nitrate reductase of P. isachenkovii reduced vanadate with NADH as an electron donor.     

Evolution of spore release mechanisms in the saprolegniaceae (Oomycetes): evidence from a phylogenetic analysis of internal transcribed spacer sequences

Classical studies on spore release within the Saprolegniaceae (Oomycetes) led to the proposition that different mechanisms of sporangial emptying represent steps in an evolutionary transition series. We have reevaluated this idea in a phylogenetic framework using internal transcribed spacer sequences of four genera. These data were compared with the response to osmotic stress exhibited by each taxon. Saprolegnia emerges as the most basal genus, sister to Achlya, Thraustotheca, and Dictyuchus. Achlya and Thraustotheca are most closely related, while Dictyuchus appears to have evolved along a separate evolutionary lineage. The resulting phylogenetic framework is consistent with the idea that the mechanism of sporangial emptying exhibited by Saprolegnia represents the plesiomorphic condition from which the other mechanisms were derived independently. These alternative mechanisms of spore release may have resulted from a small number of mutations that inhibited axonemal development and altered the temporal and spatial expression of lytic enzymes that degrade the sporangial wall. Copyright 1998 Academic Press.     

Changes in functional activity of macrophages caused by bacterial muramylpeptides

Muramylpeptides from bacteria cell wall are strong stimulators of immune system and phagocytic cells are main effectors. Dimer containing glucoseaminylmuramylpentapeptide (di-GMPP) was obtained from cell wall of Salmonella typhi bacteria. Di-GMPP decrease the phagocytic activity of macrophages obtained from peripheral blood of healthy donors and increase intracellular killing. Also di-GMPP resulted in decrease of expression of macrophages' receptors which play role in phagocytosis (CD16, CD64, CD11b) and detection of bacterial molecular patterns (TLR2, TLR4, CD206), as well as in increase of expression of antigen-presenting (HLA-DR) and costimulatory molecules (CD86, CD40) which involved in formation of immunological synapse and presentation of antigens to T- and B-lymphocytes.