Institute of
bioorganic chemistry

The nucleolus and Cajal bodies (CBs) are subnuclear structures with well-known roles in RNA metabolism. The researchers from the Laboratory of functional genomics and proteomics (IBCh, RAS) in collaboration with colleagues from the James Hutton Institute (UK) uncovered a previously unrecognised mechanism by which these structures regulate host defences against virus attack. It was shown that the CB protein coilin interacts with poly(ADP-ribose) polymerase 1, redistributes it to the nucleolus and modifies its function. These events are accompanied by activation of salycilic acid-mediated mechanism leading to the restriction of tobacco rattle virus systemic infection. The results are published in Viruses.

Scientists of the Department of Chemical Biology of Glycans and Lipids, together with colleagues from the Institute of General Pathology and Pathophysiology of the Russian Academy of Sciences, N.F. Gamaleya Research Institute and V.N. Orekhovich Institute of Biomedical Chemistry, investigated the effect of the protein corona of targeted liposomes on internalization by endothelial cells in the conditions of modeling microvessels in a microfluidic device. The ability of liposomes decorated with a tetrasaccharide selectin ligand SiaLe X to target activated endotheliocytes was preserved under microflow conditions. However, in the human serum flow, the level of liposome uptake by cells decreased. Proteomic analysis and immunoblotting of liposome-protein complexes revealed a correlation between the content of SiaLe X and some apolipoproteins, including likely nonspecific competitors of selectins. The results are published in Pharmaceutics.

Snake venoms are complex, predominantly protein, mixtures. To assess the composition of snake venoms, a team of scientists from IBCh RAS and GPI RAS proposed a method based on Raman spectroscopy, which does not require sample preparation, and the necessary amount of samples is extremely small. Raman spectrum of a protein contains unique information about its primary and secondary structures. Authors conducted a study of dry venoms of various snake species from different genera and families. On the basis of the spectra, with the help of mathematical methods, a classification of venoms was carried out, reflecting their composition and the assignment of a producing snake to the corresponding family or even genus. The method can be used to analyze composition and variations of venoms. The results are published in Journal of Materials Chemistry B. Learn more

The luciferin of the bioluminescent system of O. undecimdonta, which emits green-blue light, is an unusual heterocycle with previously unknown thieno[3,2-f]thiochromene skeleton. Despite numerous methods for the synthesis of benzothiophenes and thiochromenes, no synthetic approaches to thieno[3,2-f]thiochromenes have been proposed so far. The researchers from the Laboratory of Chemistry of Metabolic Pathways developed a convergent synthetic pathway to thieno[3,2-f]thiochromene tricarboxylate via cascade reactions with the use of bifunctional reagents, which afforded the structural confirmation of Odontosyllis undecimdonta luciferin and opened the route to other thieno[3,2-f]thiochromenes that were not accessible via known synthetic methods. The research was published in Organic Letters. Learn more

Scientists from the Department of Molecular Neuroimmune Signaling IBCh RAS together with colleagues from the Institute of Cell Biophysics and the Institute of Theoretical and Experimental Biophysics, studied the effect of cobra venom cardiotoxins on the intracellular concentration of calcium ions and the shape of rat cardiomyocytes (CaTx). Depending on the structure of the N-terminal or the central polypeptide loop, CaTx are classified into either group I and II or P- and S-types, respectively. It was shown that CaTxs of group I containing two adjacent proline residues in the N-terminal loop were less toxic to cardiomyocytes than group II toxins and CaTxs of S-type were less active than P-type ones. So, it was demonstrated that the CaTx toxicity to cardiomyocytes depends on the structures both of the N- terminal and central polypeptide loops. The paper was published in the International Journal of Molecular Sciences. Learn more