Press-room / Digest

First crystal structure of bacterial oligopeptidase B in an intermediate state: the roles of the hinge region modification and spermine
Oligopeptidase B (OpB) is a two-domain serine peptidase with trypsin-like substrate specificity. OpB belongs to the prolyl oligopeptidase (POP) family and are found only in bacteria and protozoa. It is known that OpB are pathogenesis factors of protozoan infections and protect bacterial cells from a number of antimicrobial peptides. Nevertheless, they are the least studied representatives of POP, especially bacterial OpB, for which there was a complete lack of structural information. The researches from IBC RAS together with those of NRC Kurchatov Institute and the IBOC of the National Academy of Sciences of Belarus managed to obtain crystal structures of bacterial OpB from Serratia proteomaculans (PSP) with a modified hinge region. The work was published in the Biology journal. Learn more

Mambalgin-2 inhibits growth, migration, and invasion of metastatic melanoma cells by targeting the channels containing an asic1a subunit whose up-regulation correlates with poor survival prognosis
Melanoma is aggressive cancer characterized by acidification of extracellular environment. Scientists from the Laboratory of bioengineering of neuromodulators and neuroreceptors IBCh RAS together with colleages from NN Blokhin NMRCO showed for the first time that extracellular media acidification increases proliferation, migration, and invasion of patient-derived metastatic melanoma cells and up-regulates cell-surface expression of acid sensitive channels containing the ASIC1a, α-ENaC, and γ-ENaC subunits. No influence of media acidification on these processes was found in normal keratinocytes. This work was published in Biomedicines journal. Learn more

Pseudomonas phage MD8: genetic mosaicism and challenges of taxonomic classification of lambdoid bacteriophages
Fundamental questions of the evolution of viral genomes are the most important topic of virological research. As a result of the joint work of virologists from the Laboratory of Molecular Bioengineering of the IBCh RAS and the Limnological Institute of the RAS, a group of bacteriophages of the dangerous pathogen Pseudomonas was identified, the genomes of these bacterial viruses were studied, and it was shown that their formation was greatly influenced by multiple horizontal transfers, which led to pronounced genetic mosaicism. Scientists also put forward hypotheses about the origin of the new group and proposed basic principles for the taxonomic classification of lambdoid phages. The results are published in the International Journal of Molecular Sciences. Learn more

The secreted protein disulfide isomerase Ag1, lost by ancestors of poorly regenerating vertebrates, is required for Xenopus laevis tail regeneration
As is known, unlike cold-blooded vertebrates, warm-blooded vertebrates are not able to regenerate such complex structures as a limb or tail. Earlier, researchers from the Laboratory of Molecular Bases of Embryogenesis IBCH RAS proposed a hypothesis about the relationship between the weakening of regenerative abilities in warm-blooded animals and the loss of some genes that regulate regeneration in cold-blooded animals. In support of this hypothesis, we showed that there are indeed genes essential for the regeneration among the found genes lost by warm-blooded vertebrates, particularly the gene for the secreted disulfide isomerase Ag1. Strong activation of this gene on 1 and 2 days post-amputation of the tail in a model object, the frog Xenopus laevis tadpoles, indicated its essential role at the beginning of regeneration processes. It was shown that knockdown of ag1 reduces the ability to regenerate the amputated tail. At the same time, this ability can be restored either by overexpression of ag1 or by the addition of its recombinant protein to the tadpoles. This work was published in Frontiers in Cell and Developmental Biology journal. Learn more

Mechanism of coelenterazine chromophore photoinactivation from Beroe abissycola photoprotein is proposed
Scientists from IBCh RAS with colleagues from Photobiology Lab (IBP SB RAS) elucidated the structures of Beroe abissycola photoprotein’s chromophore photoinactivation products and proposed a mechanism of the photoinactivation process. The similarity of chemical transformations of photoprotein and GFP-like fluorescent protein chromophores was demonstrated for the first time. The results are published in Organic Letters. The project was funded by the RScF grant № 17-14-01169p. Learn more