Label Distribution in Tissues of Wheat Seedlings Cultivated with Tritium-Labeled Leonardite Humic Acid.

Humic substances (HS) play important roles in the biotic-abiotic interactions of the root plant and soil contributing to plant adaptation to external environments. However, their mode of action on plants remains largely unknown. In this study the HS distribution in tissues of wheat seedlings was examined using tritium-labeled humic acid (HA) derived from leonardite (a variety of lignites) and microautoradiography (MAR).

Structural details of pectic galactan from the secondary cell walls of flax (Linum usitatissimum L.) phloem fibres.

Details of the backbone and side chain structure of pectic β-(1→4)-galactan from the secondary cell walls of flax phloem fibres were characterised by NMR and mass spectrometry of the fragments obtained after partial hydrolysis with specific endogalactanase and rhamnogalacturonan hydrolase. The proportions of branched and linear rhamnose in the backbone of the polymer equalled 72% and 28%, respectively. Rhamnose branched with a single galactose residue comprised 47% of the total rhamnose; thus, in the bulk of the polymer backbone, rhamnose had 0-1 galactose residues.

Can enantiomorphic crystals like quartz play a role in the origin of homochirality on earth?

This communication reviews the possible actions of enantiomorphic crystals on the surface of Earth as sources of homochirality of organic compounds. The discovery of asymmetric adsorption and asymmetric catalysis involving optically active quartz crystals has led some authors to conclude that this source of asymmetry played an important role as a source of homochirality in nature, a concept that later proved erroneous. Moreover, data regarding the preponderance in nature of l-quartz crystals have been used to confirm calculations of the parity violation energy difference (PVED) for l-quartz and, hence, to explain the prevalence of L-amino acids and D-sugars in living matter.

Principles of selective inactivation of a viral genome. Comparative kinetic study of modification of the viral RNA and model protein with oligoaziridines.

Comparative kinetic analysis of inactivation of bacteriophage MS2 infectivity and aminoalkylation of a model protein (trypsin inhibitor) with oligoaziridines was performed in order to evaluate the selectivity of viral RNA modification with oligocationic reagents. The transition from ethyleneimine monomer to di-, tri-, and tetramer leads to a sharp increase in the rate constant of infectivity inactivation, whereas the rate constant of protein modification changes insignificantly. The selectivity coefficient of the phage RNA aminoalkylation relative to trypsin inhibitor modification increases in this series by more than an order of magnitude.

[The carbohydrate-containing cell wall polymers of some species from the cluster "Streptomyces lavendulae"].

The type strains of the cluster "Streptomyces lavendulae" species with a low level of DNA-DNA relatedness were found to contain different cell-wall carbohydrate polymers, whereas the species of this cluster with a level of DNA-DNA relatedness of about 60% contain similar or identical carbohydrate polymers. The type strains Streptomyces katrae VKM Ac-1220T and S. polychromogenes VKM Ac-1207T synthesize mannan with different amounts of alpha-1,2- and alpha-1,3-substituted mannopyranose units and a small number of 1,3-poly(glycerophosphate) chains.

The role of quartz in the origin of optical activity on earth.

A thorough analysis of literature data on distribution of right and left quartz in many locations on the surface of Earth indicates that quartz enantiomorph crystals are distributed in equal amounts in all locations. Therefore optically active quartz crystals of one or the other enantiomorph could not serve as the source of homochirality in the evolution of biosphere. Hence the calculation of a PVED based on published 'small excess of left quartz crystals' on Earth lacks a sound physical basis.

[Modification of surface residues of lysine in immunoglobulin G using the spin marker 2,2,5,5-tetramethyl-3-maleimidopyrrolidine-1-oxyl].

Exposed lysine residues of human IgG were modified by a spin-label, 2,2,5,5-tetramethyl-3-male-imidopyrrolidine-1-oxyl at pH 9.2. Under these conditions, the degree of modification was about 10 lysine residues per protein molecule.

NMR spectroscopic elucidation of the structure of a glycerol teichoic acid-like O-specific polysaccharide of the bacterium Hafnia alvei strain PCM 1199.

The structure of the acidic O-specific polysaccharide of a Gram-negative bacterium, H. alvei strain PCM 1199, was studied by NMR spectroscopy including two-dimensional correlation spectroscopy (COSY), total correlation spectroscopy (TOCSY), nuclear Overhauser effect spectroscopy (NOESY), 1H, 13C heteronuclear single-quantum coherence (HSQC), 1H, 13C heteronuclear multiple-bond correlation (HMBC), and one-dimensional 1H, 31P heteronuclear multiple-quantum coherence (HMQC) experiments. It was found that the polysaccharide contains D-galactose, 2-acetamido-2-deoxy-D-glucose, 4-acetamido-4,6-dideoxy-D-glucose, glycerol, and phosphate in the ratios 1:2:1:1:1, as well as O-acetyl groups in non-stoichiometric amounts.

Structure of a neutral O-specific polysaccharide of the bacterium Proteus mirabilis O24.

Lipopolysaccharide of the bacterium Proteus mirabilis O24 was found to have a neutral O-specific polysaccharide chain containing D-galactose, 2-acetamido-2-deoxy-D-glucose, and 2-acetamido-2-deoxy-D-galactose in ratios 1:2:1. On the basis of 1H- and 13C-NMR spectroscopy, including two-dimensional correlation spectroscopy (COSY), H-detected 1H, 13C heteronuclear multiple-quantum coherence (HMQC), and nuclear Overhauser effect spectroscopy (NOESY), the following structure of the branched tetrasaccharide repeating unit of the O-specific polysaccharide was established: -->3)-beta-D-GlcpNAc-(1-->4)-beta-D-GalpNAc-(1-->4)-beta-D-GlcpNAc-(1--> [formula: see text] beta-D-Galp.

Structure of the O-specific polysaccharide of the bacterium Proteus mirabilis O13 containing a novel component: an amide of D-galacturonic acid with N(epsilon)-(1-carboxyethyl)lysine.

An acidic O-specific polysaccharide was obtained by mild degradation of the lipopolysaccharide of the bacterium Proteus mirabilis O13 and found to contain D-galactose, 2-acetamido-2-deoxy-D-glucose, and N(epsilon)-(1-carboxyethyl)-N(alpha)-(D-galacturonoyl)lysine. On the basis of full acid hydrolysis and 1H- and 13C-NMR spectroscopy, including two-dimensional correlation spectroscopy (COSY), H-detected heteronuclear 1H, 13C multi-quantum coherence (HMQC), and rotating-frame nuclear Overhauser effect spectroscopy (ROESY), the following structure of the branched trisaccharide repeating unit of the polysaccharide was established [structure: see text]

Structure of the O-specific polysaccharide of the bacterium Providencia alcalifaciens O23 containing a novel component: an amide of D-glucuronic acid with N(epsilon)-(1-carboxyethyl)lysine.

An acidic O-specific polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of the bacterium Providencia alcalifaciens O23 and found to contain D-glucose, D-galactose, 2-acetamido-2-deoxy-D-galactose, and N epsilon-(1-carboxyethyl)-N alpha-(D-glucuronoyl)lysine. On the basis of full and partial acid hydrolyses, selective solvolysis with anhydrous hydrogen fluoride, and 1H- and 13C-NMR spectroscopy, including two-dimensional correlation spectroscopy (COSY), H-detected heteronuclear 1H, 13C multi-quantum coherence (HMQC), and rotating-frame nuclear Overhauser effect spectroscopy (ROESY), the following structure of the liner tetrasaccharide repeating unit of the polysaccharide was established [structure: see text]

Structure of the acid-labile galactosyl phosphate-containing O-antigen of the bacterium Proteus vulgaris OX19 (serogroup O1) used in the Weil-Felix test.

The structure of the O-specific polysaccharide chain of Proteus vulgaris OX19 lipopolysaccharide which determines the O1 specificity of Proteus and is used in the Weil-Felix test for diagnostics of rickettsiosis was established. On the basis of 1H- and 13 C-NMR spectroscopy, including two-dimensional correlation spectroscopy (COSY), H-detected 1H, 13C heteronuclear multiple-quantum coherence (HMQC), and rotating-frame nuclear Overhauser effect spectroscopy (ROESY), it was found that the polysaccharide consists of branched pentasaccharide repeating units containing D-galactose, 2-acetamido-2-deoxy-D-glucose, 2-acetamido-2-deoxy-D-galactose, and 2-acetamido-2,6-dideoxy-D-glucose (QuiNAc, two residues), which are connected to each other via a phosphate group (P): [formula: see text]. The polysaccharide is acid-labile, the glycosyl phosphate linkage being cleaved at pH 4.

Fucosylation of synthetic oligosaccharides--plant xyloglucan fragments--by mammalian and amphibian fucosyltransferases.

Liver and oviduct of frogs Rana temporaria and Xenopus laevis were shown to possess the activity of beta-galactoside alpha 1-2-fucosyltransferase. Extracts of these tissues as well as porcine and rat submaxillary gland homogenates catalyze the fucosylation of synthetic plant xyloglucan fragments, the disaccharide D-Gal(beta 1-2)D-Xyl and the tetrasaccharide D-Gal(beta 1-2)D-Xyl(alpha 1-6)D-Glc(beta 1-4)D-Glc; the active preparations can be used for enzymatic synthesis of biologically active oligosaccharides.