The Specificity of Transgene Suppression in Plants by Exogenous dsRNA.

The phenomenon of RNA interference (RNAi) is widely used to develop new approaches for crop improvement and plant protection. Recent investigations show that it is possible to downregulate plant transgenes, as more prone sequences to silencing than endogenous genes, by exogenous application of double-stranded RNAs (dsRNAs) and small interfering RNAs (siRNAs). However, there are scarce data on the specificity of exogenous RNAs.

On the origin of matrix mechanism in protocells and key problems of molecular biology.

The theory of the emergence of the matrix mechanism in protocells on complexes of minerals (apatite, carbonate-apatite, calcite, and quartz) with the reciprocal proportions and with the participation of the gas phase radicals (NH3, CH4, and CO) is considered. The structure of apatite and carbonate-apatite predetermined the formation of a double helix of DNA with the complementary pairs of purine-pyrimidine bases, as well as RNA strands complementary to DNA, and helical protein chains combined into supramolecular structures with RNA. It is proposed that during the Archean Eon, a gradual replacement of the mineral matrix with organic matter took place.

Fatty Acid Composition and Thermotropic Behavior of Glycolipids and Other Membrane Lipids of Ulva lactuca (Chlorophyta) Inhabiting Different Climatic Zones.

Increasing global temperatures are expected to increase the risk of extinction of various species due to acceleration in the pace of shifting climate zones. Nevertheless, there is no information on the physicochemical properties of membrane lipids that enable the adaptation of the algae to different climatic zones. The present work aimed to compare fatty acid composition and thermal transitions of membrane lipids from green macroalgae harvested in the Sea of Japan and the Adriatic Sea in summer.

Immunogenicity and Protective Activity of a Chimeric Protein Based on the Domain III of the Tick-Borne Encephalitis Virus E Protein and the OmpF Porin of Incorporated into the TI-Complex.

Tick-borne encephalitis (TBE) is a widespread, dangerous infection. Unfortunately, all attempts to create safe anti-TBE subunit vaccines are still unsuccessful due to their low immunogenicity. The goal of the present work was to investigate the immunogenicity of a recombinant chimeric protein created by the fusion of the EIII protein, comprising domain III and a stem region of the tick-borne encephalitis virus (TBEV) E protein, and the OmpF porin of (OmpF-EIII).

Recombinant Fusion Protein Joining E Protein Domain III of Tick-Borne Encephalitis Virus and HSP70 of as an Antigen for the TI-Complexes.

Domain III (DIII) of the tick-borne encephalitis virus (TBEV) protein E contains epitopes, which induce antibodies capable of neutralizing the virus. To enhance the immunogenicity of this protein, which has a low molecular weight, the aim of the present work was to express, isolate, and characterize a chimeric protein based on the fusion of the bacterial chaperone HSP70 of and EIII (DIII + stem) as a prospective antigen for an adjuvanted delivery system, the tubular immunostimulating complex (TI-complex). The chimeric construction was obtained using pET-40b(+) vector by ligating the respective genes.

Modulation of Immunogenicity and Conformation of HA1 Subunit of Influenza A Virus H1/N1 Hemagglutinin in Tubular Immunostimulating Complexes.

The HA1 subunit of the influenza virus hemagglutinin (HA) is a valuable antigen for the development of vaccines against flu due to the availability of most antigenic sites which are conformational. Therefore, a novel adjuvanted antigen delivery system, tubular immunostimulating complexes (TI-complexes) comprising monogalactosyldiacylglycerol (MGDG) from different marine macrophytes as a lipid matrix for an antigen, was applied to enhance the immunogenicity of recombinant HA1 of influenza A H1N1 and to study the relation between its immunogenicity and conformation. The content of anti-HA1 antibodies and cytokines was estimated by ELISA after the immunization of mice with HA1 alone, and HA1 was incorporated in TI-complexes based on different MGDGs isolated from green algae , brown algae , and seagrass .

Nanoparticulate Tubular Immunostimulating Complexes: Novel Formulation of Effective Adjuvants and Antigen Delivery Systems.

New generation vaccines, based on isolated antigens, are safer than traditional ones, comprising the whole pathogen. However, major part of purified antigens has weak immunogenicity. Therefore, elaboration of new adjuvants, more effective and safe, is an urgent problem of vaccinology.

Kinetics of Spanish broom peroxidase obeys a Ping-Pong Bi-Bi mechanism with competitive inhibition by substrates.

In plants, adverse conditions often induce an increase in reactive oxygen species (ROS) such as hydrogen peroxide (H2O2). H2O2 is reduced to water, and thus becomes detoxified by enzymes such as Cytisus multiflorus peroxidase (CMP). Here, the steady-state kinetics of the H2O2-supported oxidation of different organic substrates by CMP was investigated.

Cucumarioside E from the Far Eastern Sea Cucumber Cucumaria japonica (Cucumariidae, Dendrochirotida), New Minor Monosulfated Holostane Triterpene Pentaoside with Glucose as the Second Monosaccharide Residue.

New minor triterpene glycoside, cucumarioside E (1) has been isolated from the Far Eastern sea cucumber Cucumaria japonica. The structure of the glycoside was elucidated by 2D-NMR specroscopy and mass-spectrometry. The glycoside has glucose instead of quinovose as the second monosaccharide residue and xylose as third monosaccharide residue that is unique structural feature for triterpene glycosides carbohydrate chains from sea cucumbers belonging to the genus Cucumaria.

Crystal structure analysis of peroxidase from the palm tree Chamaerops excelsa.

Palm tree peroxidases are known to be very stable enzymes and the peroxidase from the Chamaerops excelsa (CEP), which has a high pH and thermal stability, is no exception. To date, the structural and molecular events underscoring such biochemical behavior have not been explored in depth. In order to identify the structural characteristics accounting for the high stability of palm tree peroxidases, we solved and refined the X-ray structure of native CEP at a resolution of 2.

Purification and structural stability of white Spanish broom (Cytisus multiflorus) peroxidase.

New plant peroxidase has been isolated to homogeneity from the white Spanish broom Cytisus multiflorus. The enzyme purification steps included homogenization, NH(4)SO(4) precipitation, extraction of broom colored compounds and consecutive chromatography on Phenyl-Sepharose, HiTrap™ SP HP and Superdex-75 and 200. The novel peroxidase was characterized as having a molecular weight of 50 ± 3 kDa.

On the possibility of lipid-induced regulation of conformation and immunogenicity of influenza a virus H1/N1 hemagglutinin as antigen of TI-complexes.

The tubular immunostimulating complex (TI-complex) consisting of cucumarioside A2-2, cholesterol and monogalactosyldiacylglycerol (MGDG) from marine macrophytes is the perspective antigen delivery system for subunit vaccines. MGDG is a lipid matrix for the protein antigen incorporated in the TI-complex. The aim of the present work was to study the influence of MGDGs from different macrophytes on conformation and immunogenicity of the secreted recombinant uncleaved hemagglutinin monomer (HA0S) of influenza A virus H1/N1.

Thermal stability of matrix protein from Newcastle disease virus.

The thermal stability of the matrix protein (M protein) of Newcastle disease virus (NDV) has been investigated using high-sensitivity differential scanning calorimetry (DSC) at pH 7.4. The thermal folding/unfolding of M protein at this pH value is a reversible process involving a highly cooperative transition between folded and unfolded monomers with a transition temperature (Tm) of 63 °C, an unfolding enthalpy, ΔH(Tm), of 340 kcal mol(-1), and the difference in heat capacity between the native and denatured states of the protein, ΔCp, of 5.

The influence of monogalactosyldiacylglycerols from different marine macrophytes on immunogenicity and conformation of protein antigen of tubular immunostimulating complex.

The tubular immunostimulating complex (TI-complex) is a novel nanoparticulate antigen delivery system consisting of cholesterol, triterpene glycoside cucumarioside A(2)-2, and glycolipid monogalactosyldiacylglycerol (MGDG) isolated from marine macrophytes. MGDG is crucial for the formation of a lipid matrix for the protein antigen incorporated in TI-complexes. Fatty acid composition and the physical state of this glycolipid depend on the taxonomic position of marine macrophytes.

Tubular immunostimulating complex based on cucumarioside A2-2 and monogalactosyldiacylglycerol from marine macrophytes.

Background: There is an urgent need to develop safe and effective adjuvants for the new generation of subunit vaccines. We developed the tubular immunostimulating complex (TI-complex) as a new nanoparticulate antigen delivery system. The morphology and composition of TI-complexes principally differ from the known vesicular immunostimulating complexes (ISCOMs).

The fatty acid profile changes in marine invertebrate larval cells during cryopreservation.

The development of cryopreservation methods for embryonic cells and larvae of sea animals offers a great potential for marine biotechnology. Larval cells of bivalves and sea urchins were frozen to -196 degrees C using traditional cryoprotectants (Me(2)SO and trehalose) and the cryoprotective mixture developed by us. In addition to Me(2)SO and trehalose, this mixture contained an exogenous lipid extract from mussel tissues and antioxidants.

Seasonal changes of fatty acid composition and thermotropic behavior of polar lipids from marine macrophytes.

Major glyco- and phospholipids as well as betaine lipid 1,2-diacylglycero-O-4'-(N,N,N-tri-methyl)-homoserine (DGTS) were isolated from five species of marine macrophytes harvested in the Sea of Japan in summer and winter at seawater temperatures of 20-23 and 3 degrees C, respectively. GC and DSC analysis of lipids revealed a common increase of ratio between n-3 and n-6 polyunsaturated fatty acids (PUFAs) of polar lipids from summer to winter despite their chemotaxonomically different fatty acid (FA) composition. Especially, high level of different n-3 PUFAs was observed in galactolipids in winter.

The possibility of the formation of protocells and their structural components on the basis of the apatite matrix and cocrystallizing minerals.

This paper presents the author's theory on the possibility of simultaneous hard-phase synthesis of various organic molecules from gas-phase elements on the basis of the apatite matrix and cocrystallizing minerals (carbonate-apatite, calcite, mica). These molecules and their ensembles gave rise to living systems and protocells of the pro- and eukaryotic types. Synthesis might have occurred through gradual substitution of the mineral matrix by crystal organic matter.

Morphological and immunological characterization of immunostimulatory complexes based on glycoglycerolipids from Laminaria japonica.

Some physicochemical properties of glycoglycerolipids (monogalactosyldiacylglycerol, digalactosyldiacylglycerol and sulfoquinovosyldiacylglycerol) from the sea algae Laminaria japonica, as well as their ability to become incorporate into immunostimulating complexes (ISCOMs), used as a delivery system of microbial and tumor antigens in vesicular form, were studied. These glycolipids were found to differ essentially in fatty acid composition, unsaturation index and thermotropic behavior. The possibility of ISCOM modification by embedding the glycolipids studied instead of a phospholipid component in vesicles was shown.

Thermotropic behavior of major phospholipids from marine invertebrates: changes with warm-acclimation and seasonal acclimatization.

The crystal-liquid crystal-isotropic melt phase transitions of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) from muscle tissue of five species (actinia Metridium senile fimbriatum, mussel Crenomytilus grayanus, sea-urchin Strongylocentrotus intermedius, starfish Distolasterias nipon and the ascidian Halocynthia aurantium) of marine invertebrates, collected in winter at 0 degrees C and then acclimated to 18.5 degrees C for 5 days, were studied by differential scanning calorimetry and polarising microscopy. To elevate temperature from 0 to 18.

Cryopreservation of primary cell cultures of marine invertebrates.

Primary cell cultures obtained from somatic and larval tissues of bivalve molluscs and from embryos of sea urchins were frozen to -196 degrees C by two-step freezing using 10% dimethyl sulfoxide (DMSO) or/and trehalose (3-30 mg/ml) as cryoprotectants. We estimated both cell viability and the RNA synthetic activity after freeze-thaw. Total lipid extracts from the tissues of echinoderms examined as possible cryoprotective agents demonstrated a weak cryoprotective capacity.

Seasonal changes in thermotropic behavior of phosphatidylcholine and phosphatidylethanolamine in different organs of the ascidian Halocynthia aurantium.

Differential scanning calorimetry and polarising microscopy were used to investigate the crystal-liquid crystal-isotropic melt phase transitions of phosphatidylcholine (PC), and phosphatidylethanolamine (PE), isolated from muscles, gill pouches, gonads and digestive glands of Halocynthia aurantium, collected in summer and winter. We also analyzed the fatty chain composition of these phospholipids. In summer, the crystalline to liquid crystalline phase transitions of PC and PE from different organs were more co-operative than in winter.