Isolation of nisin from native solution and its purification on cationites]

It was found possible to use organic sorbents and in particular carboxylic cationites for isolation of nisin from the fermentation broth filtrate and its purification. Nisin is known as a polypeptide antibiotic applied as a preservative. The sorbents were shown to have high exchange capacities by the isolated substance and mechanical strength and resistance. They also proved to be highly stable.     

Synthesis and properties of the 14-amino derivatives of daunorubicin and carminomycin]

Interaction of 14-bromine derivatives of daunorubicin and carminomycin, as well as their aglycones with secondary amines, such as piperidine, N-methylpiperazine and morpholine was studied with a purpose of preparing new potentially antitumor antibiotics. It was found that reaction in acetone or dioxan at a temperature of 50--60 degrees C resulted in formation of 14-amino derivatives of the respective bromides. 14-Piperidinyl- and 14-(N-methylpiperazinyl)-daunorubicin, 14-piperidinyl-daunorubicinon and 14-piperidinyl-carminomycinon were prepared. The structure of the new substances was confirmed by the IR, UV and NMR spectra. The antimicrobial activity of 14-amino derivatives amounted to 10--35 per cent of the activity of the initial antibiotics, i.e. daunorubicin and carminomycin.     

Immunogenic Properties of the DNA Construct Encoding the Receptor-Binding Domain of the SARS-CoV-2 Spike Protein

Molecular Biology - The development of preventive vaccines became the first order task in the COVID-19 pandemic caused by SARS-CoV-2. This paper reports the construction of the pVAX-RBD plasmid...     

Evidence for evolutionary changes in ontogeny: Paleontological, comparative-morphological, and molecular aspects

It has been noted that the integration of modern data of paleontology, comparative morphology, developmental biology, and molecular genetics forms the basis for understanding the mechanisms of evolutionary transformations of ontogeny. Paleontological and morphological evidence of the evolutionary changes in ontogeny are considered based on the data of cell and molecular biology and developmental genetics. It is shown that reorganizations of gene regulatory cascades (mainly Hox genes) play a key role in the evolution of the axial organization of animals and modifications of the limb structure of metazoans, whereas the formation of new types of structures was apparently determined by the emergence of new populations of stem cells in embryogenesis (for example, neural crest cells in the evolution of vertebrates).     

OmpC-like porin from outer membrane of Yersinia enterocolitica: Molecular structure and functional activity

OmpC-like porin was isolated from the outer membrane (OM) of Yersinia enterocolitica cultured at 37°C (the “warm” variant) and its physicochemical and functional properties were studied. The amino acid sequence of OmpC porin was established, and the primary structure and transmembrane topology of this protein were analyzed in comparison with the OmpF porin isolated from Y. enterocolitica cultured at 6°C (the “cold” variant). Both porins of Y. enterocolitica had a high homology degree (65%) between themselves and with OmpC and OmpF porins from OM of Escherichia coli (58 and 76% homology, respectively). The secondary structure of OmpC and OmpF porins from OM of Y. enterocolitica consists of 16 β-strands connected by short “periplasmic” and longer “extracellular” loops with disordered structure, according to the topological model developed for porins of E. coli. The molecular structures of OmpC and OmpF porins of Y. enterocolitica have significant differences in the structure of the “extracellular” loops and in the position of one of three tryptophan residues. Using the bilayer lipid membrane (BLM) technique, pores formed by OmpC porin of Y. enterocolitica were shown to differ in electrophysiological characteristics from channels of OmpF protein of this microorganism. The isolated OmpC porin reconstructed into BLM displayed functional plasticity similarly to OmpF protein and nonspecific porins of other enterobacteria. The conductivity level of the channels formed by this protein in the BLM was regulated by value of the applied potential.     

Can foreign proteins imported into yeast mitochondria interfere with PIM1p protease and/or chaperone function?

When studying the fate of mammalian apocytochrome P450scc (apo-P450scc) imported in small amounts into isolated yeast mitochondria, we found that it undergoes degradation, this process being retarded if recipient mitochondria are preloaded in vivo (to about 0.2% of total organelle protein) with a fusion protein composed of mammalian adrenodoxin reductase and adrenodoxin (AdR-Ad); in parallel we observed aggregation of apo-P450scc. These effects suggest some overload of Pim1p protease and/or mtHsp70 system by AdR-Ad, as both of them are involved in the degradation of apo-P450scc (see Savel'ev et al. J. Biol. Chem. 273, 20596-20602, 1998). However, under the same conditions AdR-Ad was not able to impede the import of proteins into mitochondria and the development of the mitochondrial respiratory machinery in yeast, the processes requiring the mtHsp70 system and Pim1p, respectively. These data imply that chaperones and Pim1p protease prefer their natural targets in mitochondria to imported foreign proteins.     

Communicative multiplication of secondary disorders in blood formula and immunity in groups of intact mice caused by volatile compounds excreted by irradiated animals

It was shown that immunosupressive substances excreted by the irradiated mice are highly volatile. Even the excretion from one irradiated mouse could induce disorders in the immune system and blood formula of intact recipients exposed to the volatile substances. In turn, a dominate mouse from a group of the exposed recipients could cause the disorders in the next intact group. Samples of urine from irradiated or exposed to the volatile substances could cause the same effect. The experiments showed a mechanism of secondary post-radiation disorders in animal groups through volatile chemical signals.     

Effects of sodium nitroprusside,the nitric oxide donor,on photosynthesis and ultrastructure of common flax leaf blades

Solutions of sodium nitroprusside, a nitric oxide donor, were introduced at various concentrations into common flax (Linum usitatissimum L.) shoots with the transpirational water flow. Sodium nitroprusside and nitrate were found to exert similar effects on incorporation of ¹⁴C into photosynthetic products, leaf cell ultrastructure, and the export of assimilates from leaves. The results suggest that export of assimilates from leaves might be regulated by the products of incomplete nitrate reduction and that regulation may involve the NO-signaling system.     

Germinal granules in interstitial cells of the colonial hydroids <Emphasis Type="Italic">Obelia longissima</Emphasis> pallas, 1766 and <Emphasis Type="Italic">Ectopleura crocea</Emphasis> Agassiz, 1862

Electron-dense germinal granules, which are usually regarded as markers and key organelles of germline cells, were revealed in the interstitial (stem) cells of the colonial hydroids Obelia longissima and Ectopleura crocea. The interstitial cells of O. longissima displayed intense alkaline phosphatase activity, a histochemical marker for vertebrate embryonic stem and primary germ cells, as well as positive reaction to proliferating cell nuclear antigen (PCNA), which is an immunochemical marker for cell reproduction. Our findings and the literature data suggest the evolutionary conservation and similarity of the morphological and functional organization of potentially gametogenic stem cells in asexually reproducing invertebrates and germ cells in all studied Metazoa. The self-renewing pool of such stem cells provides the cellular source for blastogenesis and gametogenesis and the cellular basis for life functions, including both asexual and sexual reproduction.