A copper-containing protein that inhibits nitrite reductase from Pseudomonas aeruginosa

A non-blue copper-containing glycoprotein was isolated from Pseudomonas aeruginosa. The protein has a molecular mass of 10 kDa and contains 1 atom of EPR-detectable type II copper. The protein inhibits oxidation of both azurin and cytochrome c-551 catalyzed by nitrite reductase from Ps. aeruginosa. Thus, it may be considered as an endogenous inhibitor of nitrite reductase.     

A new role for PGRP-S (Tag7) in immune defense: lymphocyte migration is induced by a chemoattractant complex of Tag7 with Mts1

PGRP-S (Tag7) is an innate immunity protein involved in the antimicrobial defense systems, both in insects and in mammals. We have previously shown that Tag7 specifically interacts with several proteins, including Hsp70 and the calcium binding protein S100A4 (Mts1), providing a number of novel cellular functions. Here we show that Tag7–Mts1 complex causes chemotactic migration of lymphocytes, with NK cells being a preferred target. Cells of either innate immunity (neutrophils and monocytes) or acquired immunity (CD4⁺ and CD8⁺ lymphocytes) can produce this complex, which confirms the close connection between components of the 2 branches of immune response.     

Study of the acceptor portion of photosystem I according to the temperature relationships of P700 photoconversions

The functioning of the acceptor part of photosystem I was studied by temperature dependence of time course of light induced absorbtion changes at 700 nm of digitonin chloroplast fragments, enriched by photosystem I. Partial irreversibility of P700 photooxidation at low temperatures and appearance of two components (rapid and slow) in the time course of P700+ dark reduction reflect the contribution of different acceptors in electron transport. Thermoinactivation of fragments incubation at acid pH or treatment by glutaraldehyde cause complete inhibition of irreversible P700 photooxidation and slow dark reduction of P700+ at -170 degrees. The slow component of P700+ reduction and irreversible photooxidation of P700 are ascribed to contribution of secondary ferredoxin acceptors. The accurence of rapid component of P700+ dark reduction in light induced signal of treated fragments indicate that this component is due to recombination of reduced primary acceptor and P700+. Because only one electron transport takes at -170 degrees, the occurence of rapid and slow components in dark decay kinetics of P700+ suggests, that secondary acceptors of some reaction centers are incapable to reduction at -170 degrees. The shape of temperature dependence curve of the slow P700+ reduction component is interpreted as an indication of the tunneling electron transport.     

Kinetics of adsorption of extended ligands on DNA at small fillings

In the present work, the adsorption kinetics of extended ligands on DNA duplexes at small fillings when molecules of DNA duplexes are on the underlayer within diffusion layer has been investigated. Both diffusion of ligands in solution (diffusion stage) and adsorption of ligands (kinetic stage) are taken into consideration at adsorption of ligands on DNA duplexes. Nonlinear system of differential equations describing adsorption of ligands where not only diffusion stage but also kinetic stage is taken into account, is obtained, moreover the equations allow localizing duplexes in arbitrary place within diffusion layer. Numeric solution of the equations makes possible to investigate the filling kinetics of DNA duplexes by ligands depending on parameters controlling adsorption process. It has been shown that depending on relation between adsorption parameters different kinetic regimes of adsorption – kinetic, complex, and diffusion regimes may be realized.     

92 Novel interpretation of the isotherms of multimodal ligands binding with DNA

The binding of ligands with DNA is a key moment in a whole range of cellular processes that provide not only the normal cell vital activity but also the development of some pathological processes. Depending on ligand type, structure of DNA adsorption centers, and physical–chemical conditions of the surrounding, the ligand may bind to DNA by several modes [1]. Particularly, adsorption isotherm of multimodal ligands binding to DNA in Scatchard’s coordinates has a concave shape with two brightly expressed linear areas in the region of small fillings. The analysis of such type of adsorption isotherm for determining of important binding parameters such as binding constant and number of adsorption centers (the part of DNA polymer with which one ligand molecule binds) presents difficulties. Practically in all cases, the analysis of such adsorption isotherm is carried out by linear parts of curves. Such analysis mode of experimental points is approximate method, since all registered of experimental points are roughly divided into two groups and they are treated by linear binding isotherm and therefore the binding parameters are determined. In the present work, the non-linear adsorption isotherm in Scatchard‘s coordinates is obtained which allowed, provided, the more precise treatment of all experimental points by unique curve which includes linear regions as well. Such mode of treatment of experimental points makes more precise the determination of not only binding constant and number of adsorption centers that correspond to the one ligand molecule binding, but also additional binding parameter – a proportion of adsorption centers of each binding to DNA type of multimodal ligand.     

Fungal decomposition of oat straw during liquid and solid state fermentation

White rot fungi (Coriolus hirsutus, Coriolus zonatus, and Cerrena maxima from the collection of the Komarov Botanical Institute of the Russian Academy of Sciences) and filamentous fungi (Mycelia sterilia INBI 2-26 and Trichoderma reesei 6/16) were grown on oat straw-based liquid and solid media, as well as in a bench-scale reactor, either individually or as co-cultures. All fungi grew well on solid agar medium supplemented with powdered oat straw as the sole carbon source. Under these conditions, the mould Trichoderma reesei fully suppressed the growth of all basidiomycetes studied; conversely, Mycelia sterilia neither affected the development of any of the cultures, nor did it show any substantial susceptibility to suppression by their presence. Pure solid cultures of basidiomycetes, as well as the co-culture of Coriolus hirsutus and Cerrena maxima caused a notable bleaching of the oat straw during its consumption. When grown on the surface of oat straw-based liquid medium, the basidiomycetes consumed up to 40% polysaccharides without measurable lignin degradation (a concomitant process). Under these conditions, Mycelia sterilia decomposed no more than 25% lignin in 60 days, but this was observed only after polysaccharide exhaustion and biomass accumulation. In contrast, during solid state straw fermentation, white rot fungi consumed up to 75% cellulose and 55% lignin in 83 days (C. zonarus), whereas the corresponding consumption levels for co-cultures of Mycelia sterilia and Trichoderma reesei equaled 70 and 45%, respectively (total loss of dry weight ranged from 55 to 60%). Carbon dioxide-monitored solid-state fermentation of oat straw by the co-culture of filamentous fungi was successfully performed in an aerated bench-scale reactor.     

Delayed medical consequences of the Chernobyl accident in Armenia. Assessment of life quality and accelerated biological aging of accident liquidators

In this paper, some final results of 25-year investigations carried out in Scientific Centre for Radiation Medicine and Burns MH RA (SCRMB) on the Armenian cohort of the Chernobyl accident consequences liquidators are shown. These results show that health conditions of the liquidators became worse during the whole observation period. A considerable development of both pathological states atypical of radiation damages and diseases, which may be considered as radiation-induced ones, was determined. Rise of the sickness rate of almost all organism systems, first of all, nervous, cardiovascular, respiratory and digestive ones, was observed. In 70% of liquidators the main disease was primarily detected after working on CNPP. In the intervening years, the average number of diagnoses per 1 liquidator increased from 1.5 in 1987 to 7-8 in the recent time. In addition to the detected diseases, particular functional shifts in neuropsychological and vegetative status of the liquidators were observed. The overwhelming majority of them have increased tonicity of the sympathetic vegetative nervous system, asthenic and depressive syndromes occurring in the form of weakness, somnolence, mood instability, mental capacity decrease, and memory defects. In the paper, the results of investigations aimed at clarification of changes in biological aging processes of the liquidators and assessment of their "life quality" features in terms of physical, psychical and social welfare are considered. Biological aged-related passportization in a definite part of liquidators elucidated an accelerated aging rate. The studies were performed with the help of SF-36 inquirer and indicated that health status aggravation of the liquidators also affected their life satisfaction. The "life quality" indices of the liquidators significantly concede the overall average standards by both physical health and psychical and social welfare scales.     

Novel functions of the well-known protein--prothymosin alpha is involved in protection of cells against apoptosis and oxidative stress

Several novel functions of the well-known and intensively studied protein prothymosin alpha have recently been revealed. In addition to such traditional functions of this protein as immunomodulatory activity and stimulation of cellular proliferation, prothymosin alpha was shown to be involved in protection of cells against apoptosis and in regulation of expression of the oxidative stress-protective genes. Methods and approaches used for revelation of prothymosin alpha novel functions are described in this review.