Chemical characterization and anti-inflammatory effect of rauvolfian, a pectic polysaccharide of Rauvolfia callus.

The pectic polysaccharide named rauvolfian RS was obtained from the dried callus of Rauvolfia serpentina L. by extraction with 0.7% aqueous ammonium oxalate. Crude rauvolfian RS was purified using membrane ultrafiltration to yield the purified rauvolfian RSP in addition to glucan as admixture from the callus, with molecular weights 300 and 100-300 kD, respectively. A peroral pretreatment of mice with the crude and purified samples of rauvolfian (RS and RSP) was found to decrease colonic macroscopic scores, the total area of damage, and tissue myeloperoxidase activity in colons as compared with a colitis group. RS and RSP were shown to stimulate production of mucus by colons of the colitis mice. RSP appeared to be an active constituent of the parent RS. The glucan failed to possess anti-inflammatory activity.

Mechanism of action of DNA-hydrolyzing antibodies to DNA from blood of patients with systemic lupus erythematosus.

Four fractions of IgG antibodies to native DNA (nDNA) were obtained from blood of patients with systemic lupus erythematosus (SLE). These antibodies displayed a thermostable DNA-hydrolyzing activity and were different in affinity for DNA-cellulose and sorption on DEAE-cellulose. DNA-hydrolyzing antibodies to nDNA are metal-dependent endonucleases, cause mainly single-strand breaks in DNA, and are active over a wide range of pH. By atomic-force microscopy, three-dimensional images of DNA complexes with DNA-hydrolyzing antibodies to nDNA were obtained with nanometer resolution, and a nonprocessive action mechanism was shown for the DNase activity of antibodies to nDNA.

Special features of the DNA-hydrolyzing activity of the antibodies in systemic lupus erythematosus.

Two types of IgG anti-DNA antibodies exhibiting DNA-hydrolyzing activity have been isolated from blood serum of patients with systemic lupus erythematosus. This DNase activity of antibodies differs from serum DNases by the non-processive mode, temperature resistance, pH optimum, and the rate of DNA hydrolysis. It is suggested that the anti-DNA antibody molecule possessing DNase activity contains two sites: one site determines specificity of antibody-DNA interaction, whereas the other is responsible for manifestation of the catalytic activity.

[Electron immunohistochemical analysis of localization of neutral Mn2+-dependent DNAase. I. Synthesis of ferritin and colloidal gold conjugates with monospecific antibodies against neutral Mn2+-dependent DNAase]. / Elektronnoe immunogistokhimicheskoe izuchenie lokalizatsii neitral'noi Mn2+-zavisimoi DNKazy. I. Sintez kon''iugatov monospetsificheskikh antitel k neitral'noi Mn2+-zavisimoi DNKaze s ferritinom i kolloidnym zolotom.

Rabbit antibodies against a neutral Mn(2+)-dependent rat liver DNAse were obtained, whose specificity towards DNAse was ascertained by suppression of the enzyme activity both in vitro system and immunoblotting assays. Procedures of synthesis of ferritin and colloidal gold conjugates with antibodies are described. The biological activity of the conjugates proved to be similar to that of the original antibodies.

[Electron immunohistochemical analysis of localization of neutral Mn2+-dependent DNAase. II. Analysis of ultrastructural localization in epon sections of different organs of the rat]. / Elektronnoe immunogistokhimicheskoe izuchenie lokalizatsii neitral'noi Mn2+-zavisimoi DNKazy. II. Ul'trastrukturnaia lokalizatsiia DNKazy na éponovykh srezakh razlichnykh organov krysy.

The use of a conjugate of colloidal gold with monotypic antibodies against a neutral Mn(2+)-dependent DNAse has revealed the enzyme localization in ultrathin Epon sections of glutaraldehyde fixed tissues. Technical procedures involved in fixation, embedding, and immune reactions are described. DNAse has been established in the nuclei in both normal and regenerating liver. A protein, immunologically close to DNAse, has been identified in the nuclei of a lymph node, thymus, spleen and cerebellar cortex.

[Electron immunohistochemical analysis of localization of neutral Mn2+-dependent DNAase. III. Visualization of DNAse binding to isolated chromatin]. / Elektronnoe immunogistokhimicheskoe izuchenie lokalizatsii neitral'noi Mn2+-zavisimoi DNKazy. III. Vizualizatsiia sviazyvaniia DNKazy s izolirovannym khromatinom.

Neutral Mn(2+)-dependent DNAse is localized on isolated chromatin structures in both normal and regenerating rat liver. The enzyme was revealed located along the whole length of nucleosomal chain and in hypernucleosomal structures. However, as concerns the quantity of the enzyme, it was distributed unevently along the chromatin, thus reflecting the pattern of different functional states of native chromatin. According to biochemical and immunohistochemical data, DNAse can hydrolyse in vitro only one-stranded DNA. One of possible explanations of the observed differences in DNAse binding with native DNA chromatin and its inability to adsorb on native DNA in vitro may be the presence of hypothetical DNA-binding proteins in native chromatin making complexes with DNAse and thereby responsible for immobilization of the enzyme on chromatin structures in vivo.

[The interaction of the Ca2(+)- and Mg2(+)-dependent DNAses of sea urchin embryos with DNA]. / Vzaimodeistvie Ca2(+)- i Mg2(+)-zavisimoi DNKazy émbrionov morskogo ezha s DNK.

The interaction between Ca2+- and Mg2+-dependent DNAse from Strongylocentrotus intermedius embryos with native DNA was studied by an immunological electron microscopy method. Colloidal gold-labelling was ascertained to be an endonuclease that reacted along the whole length of the native DNA chain. After the phosphodiester bond hydrolysis the DNA-DNAse complex did not dissociate. The enzyme remained was bound with the terminal DNA fragment. Kinetics of enzymatic hydrolysis of DNA suggests the presence in the molecule of DNA of some specific nucleotide sequences which are recognized and split by the enzyme.