Inhibition of Mn 2+ -Induced Error-Prone DNA Synthesis with Cd 2+ and Zn

DNA synthesis in the living cell is a complex process involving dozens of different enzymes that participate in DNA chain duplication either directly or through various accessory processes such as unwinding DNA chains and their stabilization Bivalent metal cations are key components in the reaction of DNA synthesis. They are necessary for all polymerases as cofactors participating in the catalytic mechanism of nucleotide polymerization. All DNA polymerases are characterized by the presence of a bivalent metal cation-binding site, which includes two or three residues of aspartic or glutamic aci

The effect of raman-laser irradiation on erythrocytes of rats

The effect of RAMAN-laser irradiation on erythrocytes of rats was investigated. It was established that laser irradiation with doses used increases lipid peroxidation in membranes of red blood cells and stimulates the activity of cellular antioxidant enzymes

Neoglycoconjugate of Tetrasaccharide Representing One Repeating Unit of the Streptococcus pneumoniae Type 14 Capsular Polysaccharide Induces the Production of Opsonizing IgG1 Antibodies and Possesses the Highest Protective Activity As Compared to Hexa- and Octasaccharide Conjugates

Identifying protective synthetic oligosaccharide (OS) epitopes of Streptococcus pneumoniae capsular polysaccharides (CPs) is an indispensable step in the development of third-generation carbohydrate pneumococcal vaccines. Synthetic tetra-, hexa-, and octasaccharide structurally related to CP of S. pneumoniae type 14 were coupled to bovine serum albumin (BSA), adjuvanted with aluminum hydroxide, and tested for their immunogenicity in mice upon intraperitoneal prime-boost immunizations. Injections of the conjugates induced production of opsonizing anti-OS IgG1 antibodies (Abs). Immunization with the tetra- and octasaccharide conjugates stimulated the highest titers of the specific Abs. Further, the tetrasaccharide ligand demonstrated the highest ability to bind OS and CP Abs. Murine immune sera developed against tetra- and octasaccharide conjugates promoted pathogen opsonization to a higher degree than antisera against conjugated hexasaccharide. For the first time, the protective activities of these glycoconjugates were demonstrated in mouse model of generalized pneumococcal infections. The tetrasaccharide conjugate possessed the highest protective activities. Conversely, the octasaccharide conjugate had lower protective activities and the lowest one showed the hexasaccharide conjugate. Sera against all of the glycoconjugates passively protected naive mice from pneumococcal infections. Given that the BSA-tetrasaccharide induced the most abundant yield of specific Abs and the best protective activity, this OS may be regarded as the most promising candidate for the development of conjugated vaccines against S. pneumoniae type 14 infections