ABSTRACT
Structural and functional polymorphism of saprophytic bacterium lectin was demonstrated to be due to subunit organization of the molecule as it was shown for many lectins of plant and animal origin. Three isoforms of extracellular sialic acid-specific lectin produced by Bacillus subtilis saprophytic strain IMV B-7014 were discovered that differed for physicochemical and biological properties. The influence of the lectin isoforms on mammalian cells proliferation and morphology in vitro depends both on the subunit organization of the protein molecule and the type of cells under study.
Subject(s)
Bacillus subtilis/physiology , Lectins/pharmacology , Animals , CHO Cells , Cell Survival/drug effects , Cricetinae , Culture Media , Fibroblasts/drug effects , Food Chain , HeLa Cells , Hemagglutination Tests , Humans , Hydrogen-Ion Concentration , Isoelectric Focusing , Lectins/chemistry , Lectins/metabolism , Mice , Molecular Weight , Protein Isoforms/chemistry , Protein Isoforms/metabolism , Protein Isoforms/pharmacologyABSTRACT
The monosaccharide and fatty acid composition of water and organic phase of lectin was studied. It was established that extracellular lectin contains 15.0% of protein, 4.6% of carbohydrates, 1.0% of nucleic acids and 16.14% of lipids. The following monosaccharides were presented in the lectins: mannose, ribose, glucose and ramnose. It was established that both native lectin and its lipophylic fraction were composed of fatty acids from C15 to C19. During aggressive methanolysis anti-iso-C15 quantity was increased with a synchronous decrease of the content of all octadecanoic acid types.
Subject(s)
Bacillus subtilis/chemistry , Lectins/analysis , Bacillus subtilis/metabolism , Extracellular Space/chemistry , Extracellular Space/metabolism , Fatty Acids/analysis , Fatty Acids/metabolism , Lectins/metabolism , Monosaccharides/analysis , Monosaccharides/metabolismABSTRACT
The subunit organization and regulatory features of extracellular sialic acid specific lectin produced by saprophytic strains Bacillus subtilis IMV B-7014 have been investigated. Autofocusing method was used to identify three lectin isoforms that were distinguished by physicochemical and biological properties. Using the transcription system in vitro it was established that one of the targets of bacterial lectin action was DNA-dependent RNA-synthesis. Lectin isoforms affect differently the synthesis: from its full inhibition to the absence of the effect on the yield of RNA-transcription product.
Subject(s)
Bacillus subtilis/metabolism , Lectins/isolation & purification , Animals , Bacillus subtilis/growth & development , Bacteriophage T7/enzymology , DNA-Directed RNA Polymerases/biosynthesis , DNA-Directed RNA Polymerases/genetics , Erythrocytes/drug effects , Escherichia coli/enzymology , Hemagglutination Tests , Lectins/chemistry , Lectins/genetics , Lectins/pharmacology , Transcription, GeneticABSTRACT
The ability of natural and mutant Bacillus subtilis cultures with imperfect reparation/recombination system to synthesis of extracellular and surface lectins was investigated, and dependence of lectin production process on cultures' genotype was proved. Mutant B. subtilis recP has practically lost its ability to produce the extracellular lectins as a result of mutation of a gene of the reparation/recombination system. The application of the method "autofocusing" allowed to investigate all the spectrum oflectin molecular forms of natural B. subtilis culture and to reveal isoforms distinguished by physico-chemical and hemagglutination properties. It was shown that lectin cathode forms inhibit the transcription process from plasmid promnoter completely, and anodic forms activate the transcript formation slightly in the transcription in vitro with T7 bacteriophage DNA-dependent RNA-polymerase.
Subject(s)
Bacillus subtilis/metabolism , Lectins/biosynthesis , Mutation , Animals , Bacillus subtilis/genetics , Bacteriophage T7/metabolism , DNA-Directed RNA Polymerases/metabolism , Down-Regulation , Erythrocytes/drug effects , Hemagglutination Tests , Isoelectric Focusing , Lectins/isolation & purification , Lectins/pharmacology , Transcription, GeneticABSTRACT
The ability of Bacillus subtilis exolectin to modulate the effect of antibiotics acting as metabolic inhibitors, which can suppress the biosynthesis of cell wall glycans (ampycillin), replication (mitomycin C) and transcription (rifampycin), have been investigated on mutants of B. subtilis. Extracellular lectin was produced by B. subtilis strains B-7014 isolated from new-born calve's intestines. It was shown that the exolectin displays affinity for to sialic and uronic acids in the decreasing order: mucin, glycuronic acid, N-acetylneuraminic acid, galacturonic acid. It was established by the diffusion method and by determination of minimum inhibitory concentrations (MIC) that B. subtilis exolectin had selective activity as to bacteriostatic effect of antibiotics under study. The activity depended on the antibiotic structure and on mutant genotype defective as to the state of its replication and repair system. The lectin under study had no modulating effect on ampycillin action. There was a tendency to lower the bacteriostatic effect of rifampycin on the growth of strain BD170 (rec+) with the help of exolectin. Only in the case of mitomycin C the significant modulating effect of the bacterial lectin was manifested and its dependence on the mutant genotype was shown. The mutants sensitivity to exolectin effect decreased in the order: BD293 (polC), SB25 (recP), BD224 (recE), BD170 (rec+). Revealed ability of B. subtilis exolectin to protect the action of mitomycin C on growth of mutant BD293 (polC) with defect in the enzyme-DNA polymerase III permits supposing that the process of DNA replication is the most sensitive target for the lectin. The found dependence of modulation of the mitomycin C effect by the bacterial lectin on the genotype of mutants (rec-) demonstrated that the lectin acted following a complex mechanism mediated by a replicative and reparative complex.
