Assessment of Hedysarum theinum Krasnob. (Fabaceae) population status in Altai

The status of 22 Hedysarum theinum cenopopulations (CPs) located in subalpine and alpine vegetation belts in Kazakhstan and Altai Republic is assessed by a complex of traits. It is detected that conditions of the subalpine belt (12 CPs), where the point sum of organismal and population traits vary from high to average values, are the most favorable for this species. The pessimal state, characterized by the smallest values of most species parameters, is determined in the alpine vegetation belt at an altitude of about 2000 m above sea level in Rudnyi Altai (Kazakhstan) and a shrub community at the junction of alpine and subalpine belts on the edge of the H. theinum area in Russian Altai. A reactive-tolerant type of H. theinum population strategy is detected.     

Circular dichroism of heterochromophoric and partially regenerated purple membrane: search for exciton coupling

In order to determine the origin of the bisignate CD spectra of native purple membrane, heterochromophoric analogues containing bacteriorhodopsin regenerated with native all-trans-retinal and retinal analogues were investigated. The data collected for the purple membrane samples containing two different chromophores suggest the additive character of the CD spectra. This conclusion was supported by a series of spectra using 5,6-dihydroretinal and 3-dehydroretinal and by using 33% regenerated PM in buffer and in presence of osmolytes. Our results support the idea of conformational heterogeneity of the chromophores in the bR in the trimer, suggesting that the three bR subunits in the trimer are not conformationally equal, and therefore, the bisignate CD spectrum of bR in the purple membrane occurs rather due to a superposition of the CD spectra from variously distorted bR subunits in the trimer than interchromophoric exciton-coupling interactions.     

Expression of human α<Subscript>1</Subscript>-proteinase inhibitor in <Emphasis Type="Italic">Aspergillus niger</Emphasis>

Background  

Human α₁-proteinase inhibitor (α₁-PI), also known as antitrypsin, is the most abundant serine protease inhibitor (serpin) in plasma. Its deficiency is associated with development of progressive, ultimately fatal emphysema. Currently in the United States, α₁-PI is available for replacement therapy as an FDA licensed plasma-derived (pd) product. However, the plasma source itself is limited; moreover, even with efficient viral inactivation steps used in manufacture of plasma products, the risk of contamination from emerging viruses may still exist. Therefore, recombinant α₁-PI (r-α₁-PI) could provide an attractive alternative. Although r-α₁-PI has been produced in several hosts, protein stability in vitro and rapid clearance from the circulation have been major issues, primarily due to absent or altered glycosylation.     

Anatomo-morphological features of the leaves of <Emphasis Type="Italic">Hedysarum theinum</Emphasis> (Fabaceae) in Western Altai

The adaptation of Hedysarum theinum to the conditions of the mountainous areas of Western Altai (Kazakhstan) has been studied by observing the anatomical features of the leaf blade. The status of nine populations of Hedysarum theinum is estimated based on a study of ten anatomical features of the leaf blade. It is found that the combined values of features are the highest in subalpine habitats.     

Molecular chaperone RAP interacts with LRP1 in a dynamic bivalent mode and enhances folding of ligand-binding regions of other LDLR family receptors

The low-density lipoprotein receptor (LDLR) family of receptors are cell-surface receptors that internalize numerous ligands and play crucial role in various processes, such as lipoprotein metabolism, hemostasis, fetal development, etc. Previously, receptor-associated protein (RAP) was described as a molecular chaperone for LDLR-related protein 1 (LRP1), a prominent member of the LDLR family. We aimed to verify this role of RAP for LRP1 and two other LDLR family receptors, LDLR and vLDLR, and to investigate the mechanisms of respective interactions using a cell culture model system, purified system, and in silico modelling. Upon coexpression of RAP with clusters of the ligand-binding complement repeats (CRs) of the receptors in secreted form in insect cells culture, the isolated proteins had increased yield, enhanced folding, and improved binding properties compared with proteins expressed without RAP, as determined by circular dichroism and surface plasmon resonance. Within LRP1 CR-clusters II and IV, we identified multiple sites comprised of adjacent CR doublets, which provide alternative bivalent binding combinations with specific pairs of lysines on RAP. Mutational analysis of these lysines within each of isolated RAP D1/D2 and D3 domains having high affinity to LRP1 and of conserved tryptophans on selected CR-doublets of LRP1, as well as in silico docking of a model LRP1 CR-triplet with RAP, indicated a universal role for these residues in interaction of RAP and LRP1. Consequently, we propose a new model of RAP interaction with LDLR family receptors based on switching of the bivalent contacts between molecules over time in a dynamic mode.     

Oversulfated Chondroitin Sulfate Inhibits the Complement Classical Pathway by Potentiating C1 Inhibitor

Oversulfated chondroitin sulfate (OSCS) has become the subject of multidisciplinary investigation as a non-traditional contaminant in the heparin therapeutic preparations that were linked to severe adverse events. In this study, it was found that OSCS inhibited complement fixation on bacteria and bacterial lysis mediated by the complement classical pathway. The inhibition of complement by OSCS is not due to interference with antibody/antigen interaction or due to consumption of C3 associated with FXII-dependent contact system activation. However, OSCS complement inhibition is dependent on C1 inhibitor (C1inh) since the depletion of C1inh from either normal or FXII-deficient complement plasma prevents OSCS inhibition of complement activity. Surface plasmon resonance measurements revealed that immobilized C1inhibitor bound greater than 5-fold more C1s in the presence of OSCS than in presence of heparin. Although heparin can also inhibit complement, OSCS and OSCS contaminated heparin are more potent inhibitors of complement. Furthermore, polysulfated glycosaminoglycan (PSGAG), an anti-inflammatory veterinary medicine with a similar structure to OSCS, also inhibited complement in the plasma of dogs and farm animals. This study provides a new insight that in addition to the FXII-dependent activation of contact system, oversulfated and polysulfated chondroitin-sulfate can inhibit complement activity by potentiating the classical complement pathway regulator C1inh. This effect on C1inh may play a role in inhibiting inflammation as well as impacting bacterial clearance.     

Application of theoretical group methods in the modeling of complex systems

It has been shown that theoretical group methods can be applied in studies of complex physical and biological systems in which the phenomenon of self-organization takes place. The problem of calculating the parameters of climatic sensitivity with allowance for the cyclone-anticyclone structure of the atmosphere optically dense in the infrared region is considered as an example.     

Changes in functional activity of the synthetic apparatus of rat thymocytes under acute and chronic gamma-irradiation

The changes in functional activity of rat thymocyte synthetic apparatus (synthetic activity) under acute (7.5 Gy) and continuous (dose rates 14.4 and 0.43 cGy/day) gamma-irradiation were studied by the fluorescent microspectral analysis. It has been shown that after the acute irradiation the changes in synthetic activity occurred in three main stages. The stages reflect the depression and activation of synthetic processes that is due to interphase and reproductive cell death and urgent recovery of thymus cellularity and secondary repopulating. Under continuous irradiation with a dose rate 14.4 cGy/day in long-term period both the decrease of thymocyte synthetic activity (in most animals) and activation (in the animals with pronounced symptoms of radiation damage) were observed. This reflects the depression processes in immune system and augmentation of immunoreactivity due to mass antigen influence of transformed cells and infectious agents on thymocytes. Under low dose ionizing irradiation (dose rate 0.43 cGy/day) the undulating changes in synthetic processes in thymus cells were observed. This depends on the recurrence of depression and recovery processes in the blood-forming tissue.     

Functional activity of ganglion neurons from the pond snail upon temperature variations

Changes in the functional state of the synthetic apparatus of neurons of the peripharyngeal ring of the mollusk Lymnaea stagnalis upon elevating the temperature of the habitat from 4 to 18-22 degrees C were studied. In the first series of experiments, it was found that the synthetic activity of neurons of the great and small parietal, visceral, and pleural ganglia increases on the average by 70%. In the second series of experiments, changes in the average synthetic activity for all ganglia at 4.0, 6.5, 13.0, 16.8, 20.5, 21.5, 21.9, and 22.0 degrees C were studied. The increase in the synthetic activity of neuron cytoplasm (35% higher than the control values at 4.0 degrees C) was maximal at 13.0 degrees C; then the synthetic activity decreased to reach the level 20% higher than the control. The physiological range of temperature-dependent changes in the functional state of neurons was determined.     

Correlation between change in solar activity and functional activity of animal blood lymphocytes in norm and pathology

It is shown that the correlation between solar activity variations and the state of lymphocyte in norm is depressed under influence of stronger internal (gall-stone disease) and external (continuous gamma-irradiation) effects in pathology.