[Pectic polysaccharides in the stem calli of the rowan tree Sorbus aucuparia L].

The water-soluble polysaccharide fractions SAcI and SAclI were isolated from rowan tree stem calli. The SAcI fraction was shown to contain compounds belonging to the arabinogalactan II group. The SAcII fraction, termed sorban, was found to contain pectic polysaccharides that make up the protopectin complex of the cell wall callusand that had a high content of galacturonic acid residues together with neutral sugars characteristic of rhamnogalacturonan I (RG-I) polysaccharides. Using methylation assays, some structural features of the ramified region of sorban were elucidated. The backbone of sorban was found to consist of 1,4-α-D-galacto-pyranosyluronic acid residues. The neutral sugars are represented by 1,6-linked galactopyranose and 1,5-linked arabinofuranose residues as the primary constituents, as well as 1,6-linked mannopyranose and 1,4-linked glucopyranose and xylopyranose residues. Callus growth was shown to be accompanied by nearly constant quantities of galacturonic acid and neutral sugar residues in sorban (fraction SAcII) from the rowan stem callus.

[Study of Yersinia pseudotuberculosis surface antigen epitopes using monoclonal antibodies].

A study of the influence of exogenous factors on the immunochemical activity of the bacterium Yersinia pseudotuberculosis and lipopolysaccharide preparations isolated from bacteria was performed using monoclonal antibodies. It was shown that the hybridomas that were obtained in this work produce antibodies against different and, most likely, species-specific epitopes associated with lipopolysaccharide O side chains. The antibody concentrations produced increased with a decrease in the temperature, at which the bacteria were cultivated. An inhibitory effect of proteinase K, pepsin, and trypsin on the immunochemical activity of bacterial cells, determined using a solid-phase enzyme immunoassay, was demonstrated. Treatment with sodium periodate showed no uniform effect on the reactions between monoclonal antibodies and antigens (lipopolysaccharides and microbial cells), as adjudged by an immunoassay, which is most likely a consequence of the different localization of lipopolysaccharide epitopes recognized by the antibodies from four hybridomas.

[Effect of the rol genes from Agrobacterium rhizogenes on the content and structure of pectic substances and glycanase activity in Rubia cordifolia transgenic cell cultures].

The expression of the rolB gene was found to increase the pectic yield in Rubia cordifolia cells, while the rolC gene inhibited the pectin production, which correlated with its expression level. The expression of the rolA, rolB, and rolC genes led to an increase in the content of arabinogalactan (AG) in cells. The increase in the expression of the rolB and rolC genes resulted in a more significant reduction in the content of arabinose residues in pectin, which was accompanied by an increased activity of alpha-L-arabinofuranosidase in cells. Moreover, the amount of galactose residues in pectin increased with the enhancement of the rolB expression due to a decrease in the activity of beta-galactosidase in cells. The content of galacturonic acid residues in pectin from transgenic cultures increased in the following order: rolC < rolB < rolA. The amount of arabinose residues in AG decreased independently of the gene type. The amount of arabinose residues in AG was found to be considerably reduced when the rolB expression level was increased.

[Immunobiological properties of Yersinia pestis antigens].

The present review contains information concerning immunobiological properties of plague microbe antigens. All of the identified antigens are evaluated in relation to pathogenicity of Yersinia pestis namely a resistance to phagocytosis, toxicity, adhesiveness etc. as well as persistence ability and adaptation to variable environment. In addition, the role of antigens in immunogenicity of living plague microbe for experimental animals is considered. The data concerning mechanisms of antigenic contribution to the development of adaptive immunity are presented.

[Pectin substances of the callus culture of Silene vulgaris (M.) G].

Pectin-protein fraction SVC was isolated from the callus culture of the bladder campion (Silene vulgaris). The main components in it were residues of D-galacturonic acid, galactose, arabinose, rhamnose, and protein. Using ion-exchange chromatography, ultrafiltration, and acid and enzymatic hydrolysis, it was shown that SVC contained a mixture of molecules of linear pectin, branched pectin polysaccharide, and pectin-protein polymer. A fragment of the linear chain of galacturonan amounted to more than half of the entire carbohydrate silenan chain. The branched area of the macromolecule is represented by rhamnogalacturonan I. The pectin-protein polymer consisted mainly of protein and weakly branched pectin fragments with molecular mass of more than 300 kDa.

[Current information about pectin substances].

This review concerns pectin substances, the most complex class of plant polysaccharides. For the most part, the data reported after 1998 are presented; the references to earlier works are made only in the historical aspect. New data on the structure of pectin substances, their physiological activity, their role in plants, and their valuable physical properties are surveyed.

[Modified arabinogalactanes from callus culture Silene vulgaris (M.) G].

The cultivation of Silene vulgaris (M.) G. callus culture on the nutrient mediums contained carbohydrates, phytohormones, nitrogen, and phosphate has led to the modification of the arabinogalactane structure from the cell walls. It was noticed that a sucrose concentration increase in the cultivation medium led to an increase of the arabinogalactane enzyme yield with a molecular weight more than 300 kDa and a decrease of the yield of fragments with molecular weight less than 300 kDa. The sucrose concentration increase in the nutrient medium entailed the increase of arabinose and galactose content in the fragment with the molecular weight more than 300 kDa and a decrease in the fragment with a molecular weight of 100-300 kDa. On the nutrient medium containing a mix of sucrose and arabinose, the yield of the fraction with a molecular weight more than 300 kDa and the amount of arabinose residues increased, and the yield of minor fragments and the content of arabinose and galactose residues, included in these, decreased. On the medium containing an increased concentration of 2,4-dichlorphenoxiacetic acid, the yield of high-molecular fragment and the concentration of arabinose are two times increased. The decreasing of the amount of arabinose and galactose residues in the fragment with a molecular weight of 300 kDa was observed at a lack of nitrogen or phosphate in the nutrient medium.

[The effects of ultraviolet irradiation upon structure and antioxidant activity of silenan from bladder campion callus].

Effects of UV-B (280-315 nm) and UV-C (254 nm) at various doses upon callus of bladder campion (Silene vulgaris (M.) G. were studied. It was revealed that UV irradiation results in the decrease in arabinose and galactose residues in the silenan--the pectin fraction isolated from callus. The silenan possesses antioxidant activity (AOA) as assessed by the reaction with a stable radical. At the irradiation of callus by UV, the AOA of the silenan and the relative content of phenolic compounds in it increased; the highest increase was observed after the irradiation of callus by UV-B. Positive correlation between the AOA of the pectin fraction and an increase in phenolic compounds was revealed. This evidences that the AOA of the silenan relates to and is partially determined by phenolic compounds in its composition. The UV irradiation may be used as a tool to modify the structural features of the cell walls' polysaccharides in order to produce physiologically-active polysaccharides with desired properties.

[Production of polysaccharides by callus cultures of common duckweed].

Callus lines of common duckweed produced acid arabinogalactan and pectin in an amount varying from 1 to 3% of dry weight. The arabinogalactan specimens from the cell lines studied displayed a similar monosaccharide composition. The duckweed callus lines whose arabinogalactans contained apiose residues (1-2%) were found. All pectin specimens had a similar qualitative monosaccharide composition but differed in the quantitative content of monosaccharide residues. The lines with high contents of galactose, arabinose, and apiose in pectin specimens were obtained. The total content of neutral monosaccharide residues in pectins varied from 26 to 50%.

[Structural study of bergenan, a pectin from Bergenia crassifolia].

A pectin polysaccharide named bergenan was isolated from the freshly collected leaves of the leather bergenia Bergenia crassifolia by extraction with an aqueous solution of ammonium oxalate. The main component of its carbohydrate chain was shown to be the residues of D-galacturonic acid (about 80%). In addition, the polysaccharide contains residues of galactose, arabinose, and rhamnose; their total content is less than 15%. It was shown that the bergenan samples from bergenia leaves collected at different vegetation periods (from July to September) do not substantially differ either in monosaccharide composition or in the viscosity of aqueous solutions they form. The results of enzymatic hydrolysis by alpha-1,4-galacturonase (pectinase), partial acidic hydrolysis, NMR spectroscopy, and methylation with subsequent analysis of the results by GC-MS indicate that the bergenan macromolecule contains the regions of a linear alpha--1,4-D-galactopyranosyluronan and rhamnogalacturonan-I (RG-1). Galacturonan responds for a greater part of the macromolecule. A considerable amount of its constituent galacturonic acid residues are present as methyl esters. The side chains in RG-I are attached to the rhamnopyranose residues of the main carbohydrate chain by 1,4-link and are composed of the residues of terminal arabinofuranose and galactopyranose, 1,5-linked (-arabinofuranose, and 1,4-and 1,6-linked beta-galactopyranose. The branching points of the side chains of the RG-I molecule are 3,4- and 3,6-di-O-substituted galactose residues.

[Inhibition of neutrophil adhesion by pectic galacturonans].

The inhibition of the adhesion of neutrophils to fibronectin by the fragments of the main galacturonan chain of the following pectins was demonstrated: comaruman from the marsh cinquefoil Comarum polustre, bergenan from the Siberian tea Bergenia crassifolia, lemnan from the duckweed Lemna minor, zosteran from the seagrass Zostera marina, and citrus pectin. The parent pectins, except for comaruman, did not affect the cell adhesion. Galacturonans prepared from the starting pectins by acidic hydrolysis were shown to reduce the neutrophil adhesion stimulated by phorbol 12-myristate 13-acetate (1.625 microM) and dithiothreitol (0.5 mM) at a concentration of 50-200 microg/ml. The presence of carbohydrate chains with molecular masses higher than 300, from 100 to 300, and from 50 to 100 kDa in the galacturonan fractions was proved by membrane ultrafiltration.

[Polysaccharides of cell cultures of Silene vulgaris].

Callus and suspension cultures of campion (Silene vulgaris) produced pectin polysaccharides, similar in structure to the polysaccharides of intact plants. The major components of the pectins were D-galacturonic acid, galactose, arabinose, and rhamnose residues. The maximum content of pectins was found in callus. The monosaccharide composition of arabinogalactans isolated from cells and a culture medium of callus cultures were similar, with the ratio between arabinose and galactose of 1: (2.3-6.5) being retained. The arabinogalactans from the cells and culture medium of the suspension cultures also had a similar structure, and the arabinose to galactose ratio was 1: (1.5-1.8). In contrast to the callus cultures, the suspension cultures produced arabinogalactans with an increased content of arabinose residues and a decreased content of galactose residues. The greatest content of arabinogalactan was detected in the culture medium of the suspension cultures.

[The effect of ultraviolet radiation on the growth and polysaccharide composition of a callus culture of Silene vulgaris].

Ultraviolet radiation (wavelength, 280-315 nm; power, 0.2-13.0 W/m2; exposure, 1 or 3 h) was shown to change the growth of campion callus and the polysaccharide (pectin and arabinogalactan) composition of cell walls. An increase in the concentration of polysaccharides and a decrease in the content of arabinose and galactose residues in pectin and arabinogalactan were noted. For the majority of calluses, growth indices, specific growth rate, and biomass productivity (per 11 medium) were almost the same as in nonirradiated control cells. Maximum values of the growth index and specific growth rate, determined for dry biomass, were observed at a low dose of irradiation (0.2 W/m2) and an exposure of 3 h. A considerable decrease in the content of arabinose and galactose in pectin was noted at high doses of irradiation (exposure, 3 h). Samples of arabinogalactan were characterized by variable arabinose to galactose ratios, which were in the range 1 : (3.4-8.3).

[Polysaccharides of flower plants: structure and physiological activity]. / Polisakharidy tsvetkovykh rastenii: struktura i fiziologicheskaia activnost'.

The results of studies on the chemical structure and physiological activity of phanerogam polysaccharides, accumulated within the last two decades, are reviewed. Three types of polysaccharides are considered: rhamnogalacturonans (pectins and related gums and mucilages, type A), acidic arabinogalactans (mainly plant mucilages, gums, and some hemicelluloses, type B), and neutral glucans and heteroglycans (reserve polysaccharides, type C). Various physiological activities of these plant polysaccharides are discussed, with particular emphasis being placed on their immunomodulatory action. The data available on the relationship between chemical structure and physiological activity of plant polysaccharides are considered. Information on the medicinal use of some plants containing physiologically active polysaccharides is presented.

[Lipopolysaccharide-protein complexes of the outer membrane of gram-negative bacteria]. / Lipopolisakharid-belkovye kompleksy vneshnei membrany gramotritsatel'nykh bakterii.

The evidence for occurring lipopolysaccharide-protein complexes in the outer membrane of gram-negative bacteria has been summarized. The composition and supramolecular structure of these complexes as well as their functions in microbial envelope and substantial role in membrane organization have been discussed. The biological properties of the complexes as endotoxins and O-specific antigens have been considered.

[Structure of the O-specific polysaccharide chain of the lipopolysaccharide from Yersinia intermedia serotype O:4.33]. / Struktura O-spetsificheskoi polisakharidnoi tsepi lipopolisakharida Yersinia intermedia serovara O: 4,33.

O-specific polysaccharide has been isolated on autohydrolysis of lipopolysaccharide from Yersinia intermedia O: 4.33 (strain 1476) and shown to consist of the yersiniose B (3.6-dideoxy-4-C-(1-hydroxyethyl)-xylo-hexose) and 2-acetamido-2-deoxy-D-galactose residues in a molar ratio of 1 : 2. Acid hydrolysis, methylation. solvolysis with anhydrous hydrogen fluoride. and 13C-NMR studies indicate the polysaccharide to be composed of trisaccharide repeating units of the following structure: (Formula: see text).

[Synthesis of lipid A analogs: achievements and perspective]. / Sintez analogov lipida A: dostizheniia i perspektivy.

Data on the synthesis of analogues of lipid A, a biologically active fragment of gram-negative bacteria's lipopolysaccharides, are summarized. Main types of the compounds obtained are systematized, and problems of the synthesis of various parts of the molecule considered. The results of studying biological activity of lipid A analogues are discussed, which led to some conclusions on the structure-function relation. Perspectives of further studies are briefly outlived.

[Quantitative determination of the carbohydrate determinants of O-antigens of Yersinia pseudotuberculosis and Pseudomonas fluorescens]. / Kolichestvennoe opredelenie uglevodnykh determinant O-antigenov Yersinia pseudotuberculosis i Pseudomonas fluorescens.

Interactions of O-specific polysaccharides, LPS and LPS-protein complex with specific antibodies isolated on a polysaccharide-substituted immunoadsorbent gel and monovalent Fab-fragments of the antibodies were investigated. The association constants and quantity of Fab-fragments bound to these antigens were established. The interaction of the LPS and LPS-protein complexes was shown to depend considerably on concentration of antigens, and only 10-15% of carbohydrate determinants are accessible for binding with antibodies.

[Isolation and physico-chemical properties of a protein, included in an endotoxin from Yersinia pseudotuberculosis]. / Vydelenie i fiziko-khimicheskaia kharakteristika belka, vkhodiashchego v sostav éndotaksina iz Yersinia pseudotuberculosis.

A major protein of the endotoxin from Yersinia pseudotuberculosis was isolated from the complex lipid A--protein by treatment with SDS and triton X-100 followed by gel-chromatography on Sephacryl S-300. Protein has apparent molecular mass 40 kDa and alanine as N-terminal amino acid residue. CD and IR spectroscopy conformational changes of the protein molecule in the process of its isolation. The thermal and pH stabilities of the protein were investigated by the methods of intrinsic fluorescence and differential scanning microcalorimetry. The isolated protein revealed two thermal transitions (at 30-35 and 50-55 degrees C), which depend on Ca2+ concentration.

[Study of a lipid A-protein complex from Yersinia pseudotuberculosis endotoxin]. / Izuchenie kompleksa lipid A-belok iz éndotoksina Yersinia pseudotuberculosis.

Mild acid hydrolysis of endotoxin of Yersinia pseudotuberculosis afforded a lipid A--protein complex composed of amino acids and all characteristic components of lipid A: glucosamine, dodecanoic, 3-hydroxytetradecanoic acids and phosphorus in a molar ratio of 2 : 1,5 : 2,8 : 1,7, respectively. The protein component of the complex was shown by gel electrophoresis in the presence of sodium dodecylsulphate to consist of two polypeptides with apparent molecular weights of 12000 and 8000. The lipid A--protein complex cross-reacted with antiserum to endotoxin and lipid A antiserum. The components of the complex, namely lipid A and a protein, are associated tightly but noncovalently and can be separated by ultracentrifugation in the sucrose density gradient after treating the complex with sodium dodecylsulphate. The resultant lipid A and the protein manifest a serological activity.