A selective method for sequential splitting of O- and N-linked glycans from N,O-glycoproteins.

O-Linked oligosaccharides from N,O-glycoproteins were selectively split off by treatment with alkaline sodium borohydride in the presence of cadmium salt. The side reaction of reductive cleavage of N-glycosylamide and peptide bonds, observed under standard conditions of splitting of O-linked chains (M NaBH4 and 50mM NaOH, 16 h, 50 degrees), was inhibited by addition of 50-10 mM cadium acetate and 5-10mM EDTA.Na4, as shown by treatment of model compounds and several glycoproteins (ovomucoid, group-specific glycoproteins H and B, fetuin, and asialofetuin). This treatment, in combination with the previously developed procedure for the release of the N-linked oligosaccharide chains by lithium borohydride, allows a sequential, selective cleavage of O-, and then N-linked oligosaccharides from N,O-glycoproteins by chemical methods.     

The protective properties of a porin from the outer membrane of Yersinia pseudotuberculosis

The protective properties of the species-specific pore-forming polypeptide of Y. pseudotuberculosis outer membrane (porin) were studied. The study showed that 80-90% of mice immunized with porin survived after challenge with 10-30 LD50 of Y. pseudotuberculosis, serovars 1 and 3. The LD50 of the preparation exceeded its ED50 more than 100-fold. Immunization made in two injections was more effective than immunization in one injection. The immunization of the animals with porin led to an increase in the activity of peritoneal exudate macrophages with respect to Y. pseudotuberculosis, serovars 1 and 3.     

Heterogeneity of nucleotide sequences of 16S ribosomal RNA genes from the Desulfotomaculum kuznetsovii type strain]

Two copies of the 16S rRNA gene, rrnA and rrnB, of the type strain 17T of the thermophilic sulfate-reducing bacterium Desulfotomaculum kuznetsovii were cloned and completely sequenced. The comparison of the determined sequences revealed considerable heterogeneity (8.3%) of the two genes, rrnA and rrnB. The main differences were associated with superlong inserts located at the variable 5'- and 3'-terminal regions of the 16S rRNA genes. Comparative analysis that involved analogous genes from the phylogenetically closest representatives of the genus Desulfotomaculum showed that disregard of the heterogeneity of the two gene copies distorts the position of the bacterium studied in the phylogenetic tree.