Comparative-morphological characteristics of spleen of the perch <Emphasis Type="Italic">Perca fluviatilis</Emphasis> L. from lakes with different water pH level

Quantitative composition of leukocytes and structure of spleen of the perch Perca fluviatilis L. from water reservoirs with different pH and color of water were studied. Changes of proportion of lymphocytes, macrophages, and band neutrophils are shown in fish from reservoirs with different pH level. Two types of small blood vessels are revealed and changes of their structure are described: thickening of the connective tissue layer, the appearance of fibroblast-like cells, an increase of folding of the basal part of the endotheliocyte membrane. Probable association of the revealed changes with pH level in the water reservoirs and their hydrochemical conditions is discussed.Translated from Zhurnal Evolyutsionnoi Biokhimii i Fiziologii, Vol. 41, No. 1, 2005, pp. 89–94.Original Russian Text Copyright © 2005 by Zabotkina.     

Carbonate system of the Razdolnaya River estuary (Amur Bay, Sea of Japan)

Two methods, the total alkalinity measurement by Bruevich [4] and pH measurement in a cell without liquid junction [11], were suggested for study of the carbonate system of estuaries. Based on new measurements, the empirical equations were obtained for the first and second seawater concentration constants of carbonic acid for the ranges of salinity 0–40 and temperatures 0–30°C. Applying the constants and above methods, we studied the carbonate system of the Razdolnaya River-Amur Bay estuary in two expeditions of July 2001, the first in a period of average water level and the second after a flood. In the latter survey, extremely low values (60 µatm) of pCO₂ (carbon dioxide partial pressure) were recorded in the seaward part of the estuary and extremely high ( 13 300 µatm) were noted in the river. High pCO₂ in the surface water was caused by intense bacterial activity, and low levels were caused by phytoplankton bloom. The nonconservative behavior of the total alkalinity and dissolved inorganic carbon was revealed in the estuary. Based on the data of the carbonate system, the production/destruction of organic matter was assessed.Original Russian Text Copyright © 2005 by Biologiya Morya, Tishchenko, Wong, Volkova, Gramm-Osipov, Johnson, Dudarev, Zvalinskii, Nedashkovskii, Pavlova, Chichkin, Sagalaev, Shevtsova, Shkirnikova.     

Roles of water molecules in bacteria and viruses

In addition to water, microbes mainly comprise lipids, carbohydrates, proteins and nucleic acids. Their structure and function singularly and conjointly is affected by water activity. Desiccation leads to dramatic lipid phase changes whereas carbohydrates, proteins and nucleic acids initially suffer spontaneous, reversible low activation energy Maillard reactions forming products that more slowly re-arrange, cross-link etc. to give non-native states. While initial products spontaneously may reverse to native states by raising water activity, later products only do so through energy consumption and enzymatic activity eg. repair. Yet, native states of lipid membranes and associated enzymes are required to generate energy. Consequently, good reserves of high energy compounds (e.g. ATP) and of membrane stabilisers (e.g. trehalose) may be expected to enhance survival following drying and rehydration (e.g. anhydrobiotic organisms).Presented at the Session Water in the Solar System and Its Role in Exobiology, during the 26th General Assembly of the European Geophysical Society, 22–26 April 1991 in Wiesbaden, Germany     

Generation of superoxide-radical by the NADH: Ubiquinone oxidoreductase of heart mitochondria

Besides major NADH-, succinate-, and other substrate oxidase reactions resulting in four-electron reduction of oxygen to water, the mitochondrial respiratory chain catalyzes one-electron reduction of oxygen to superoxide radical followed by formation of hydrogen peroxide. In this paper the superoxide generation by Complex I in tightly coupled bovine heart submitochondrial particles is quantitatively characterized.The rate of superoxide formation during -controlled respiration with succinate depends linearly on oxygen concentration and contributes approximately 0.4% of the overall oxidase activity at saturating (0.25 mM) oxygen. The major part of one-electron oxygen reduction during succinate oxidation (80%) proceeds via Complex I at the expense of its -dependent reduction (reverse electron transfer). At saturating NADH the rate of formation is substantially smaller than that with succinate as the substrate. In contrast to NADH oxidase,the rate-substrate concentration dependence for the superoxide production shows a maximum at low (50 µM)concentrations of NADH. NAD⁺ and NADH inhibit the succinate-supported superoxide generation. Deactivation of Complex I results in almost complete loss of its NADH-ubiquinone reductase activity and in increase in NADH-dependent superoxide generation. A model is proposed according to which complex I has two redox active nucleotide binding sites.One site (F) serves as an entry for the NADH oxidation and the other one (R) serves as an exit during either the succinate-supported NAD⁺ reduction or superoxide generation or NADH-ferricyanide reductase reaction.Translated from Biokhimiya, Vol. 70, No. 2, 2005, pp. 150–159.Original Russian Text Copyright © 2005 by Vinogradov, Grivennikova.This revised version was published online in April 2005 with corrections to the post codes.     

The role of body surfaces and ventilation in gas exchange of the abalone, <Emphasis Type="Italic">Haliotis iris</Emphasis>

The archaeogastropod Haliotis iris possesses paired bipectinate gills and normally four to six shell holes. In still water, endogenous water flow entered the branchial chamber anteriorly to the left of the head and was exhaled primarily from the three most posterior holes. The first or second anterior aperture was occasionally weakly inhalant. Cardiac interaction superimposed an oscillatory component upon ciliary ventilation but did not augment mean flow. At normal endogenous flow rates 49% of oxygen was extracted from the branchial flow, increasing to 71% at lower flows. In still water, normoxic was 0.47 μmol g⁻¹ h⁻¹. Oxyregulation occurred down to with partial oxyregulation down to 45 Torr (P _crit), and oxyconformity below this. The oxyregulatory plateau was absent in artificially ventilated animals but normoxic was higher (0.65 μmol g⁻¹ h⁻¹). Endogenous ventilation was unaffected by hypoxia to 15 Torr. Heart rate decreased by ~20% at 26 Torr before falling more steeply. Oxygen uptake from the branchial ventilation stream fully accounted for normoxic In hypoxia (<30 Torr), no uptake occurred from the head or foot despite extensive eversion of the epipodium. Blood oxygen measurements excluded the right mantle as a significant gas exchange organ. Changes in oxygen uptake caused by changes in the velocity of external water currents support the concept of induced ventilation and suggest that in still water aerobic respiration was ventilation-limited. Although ciliary ventilation appears adequate to support resting aerobic metabolism, induced ventilation may provide increased aerobic scope for activity and repayment of oxygen debt. An erratum to this article can be found at     

The activity of nitrate reductase and the pool sizes of some amino acids and some sugars in water-stressed maize leaves

The activity of nitrate reductase and the pool sizes of some amino acids and some sugars were measured in relation to the leaf water potential () of maize leaves. The activity of nitrate reductase was severely inhibited in water-stressed maize leaves. This was not due to substrate shortage or the presence of an inhibitor at reduced leaf water potential. While the typical proteinogenic amino acids valine, tyrosine, leucine and isoleucine were almost undetectable in the leaves of the control plants, their concentrations markedly increased with declining , thus indicating protein degradation. The concentrations of serine, glycine and glutamate increased upon water stress, their total amount in severely stressed leaves ranging 5- to 6-fold higher than the total amount of valine, tyrosine, leucine and isoleucine at this stage of water deficit. The pool sizes of glucose, fructose and sucrose decreased in relation to decreasing . The total amount of organic solutes remained almost constant at least up to a of approx.—1.0 MPa and then dropped to about 50% when reached –1.25 MPa.Abbreviations PCR photosynthetic carbon reduction cycle - PCO photosynthetic carbon oxidation cycle - PAR photosynthetically active radiation     

Developmental features of the formation of the brain bioelectrical activity in children with remote consequences of a perinatal lesion of the CNS: I. spontaneous activity

Investigation of the brain bioelectrical activity in children with remote consequences of perinatal CNS pathology showed that the typical mature EEG of young schoolchildren of the risk group has some specific features, which reflect a CNS lesion of a predominantly hypoxic origin. This specific temporal EEG pattern combines the mature basic () rhythm with slow and sharp activities. Sufficient compensatory possibilities of the CNS and their adequacy to increasing loads at school form a basis for efficient individual adaptation. Learning problems arise in the course of a childs development when compensation is insufficient because of a severe brain lesion or slower spontaneous rehabilitation, which is related, in particular, with the rigidity of brain mechanisms determining the complete maturation of the biorhythm structure necessary for the efficient integrative activity of the brain.Translated from Fiziologiya Cheloveka, Vol. 31, No. 1, 2005, pp. 5–14.Original Russian Text Copyright © 2005 by Kozhushko.     

Proton transfer dynamics at membrane/water interface and mechanism of biological energy conversion

Proton transfer between water and the interior of membrane proteins plays a key role in bioenergetics. Here we survey the mechanism of this transfer as inferred from experiments with flash-triggered enzymes capturing or ejecting protons at the membrane surface. These experiments have revealed that proton exchange between the membrane surface and the bulk water phase proceeds at 1 msec because of a kinetic barrier for electrically charged species. From the data analysis, the barrier height for protons could be estimated as about 0.12 eV, i.e., high enough to account for the observed retardation in proton exchange. Due to this retardation, the proton activity at the membrane surface might deviate, under steady turnover of proton pumps, from that measured in the adjoining water phase, so that the driving force for ATP synthesis might be higher than inferred from the bulk-to-bulk measurements. This is particularly relevant for alkaliphilic bacteria. The proton diffusion along the membrane surface, on the other hand, is unconstrained and fast, occurring between the neighboring enzymes at less than 1 µsec. The anisotropy of proton dynamics at the membrane surface helps prokaryotes diminish the futile escape of pumped protons into the external volume. In some bacteria, the inner membrane is invaginated, so that the ejected pro tons get trapped in the closed space of such intracellular membrane sacks which can be round or flat. The chloroplast thylakoids and the mitochondrial cristae have their origin in these intracellular structures.Translated from Biokhimiya, Vol. 70, No. 2, 2005, pp. 308–314.Original Russian Text Copyright © 2005 by Mulkidjanian, Cherepanov, Heberle, Junge.This revised version was published online in April 2005 with corrections to the post codes.     

Cross-effects of extracellular factors of adaptation to stress in <Emphasis Type="Italic">Luteococcus casei</Emphasis> and <Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis>

Saccharomyces cerevisiae yeasts (lower eukaryotes) were shown to produce a protein exometabolite with reactivation activity. We demonstrated cross-effects of extracellular protein factors of adaptation to stress (heat and UV irradiation) in yeasts and Luteococcus casei bacteria. The possibility for isolation and partial purification of protein exometabolites from the culture liquid of yeasts and bacteria by similar methods, as well as the similarity of elution profiles for the active proteins in high-performance liquid chromatography, suggests that the proteins (or fragments thereof) of the organisms studied are homologous.Translated from Prikladnaya Biokhimiya i Mikrobiologiya, Vol. 41, No. 2, 2005, pp. 171–175.Original Russian Text Copyright © 2005 by Vorobeva, Khodzhaev, Ponomareva.     

The synthesis of hydroxybutyrate and hydroxyvalerate copolymers by the bacterium Ralstonia eutropha

The paper deals with the study of the synthesis of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) copolymers by the bacterium Ralstonia eutropha B-5786 grown under different carbon nutrition conditions (growth on carbon dioxide, fructose, and CO₂-valerate and fructose-valerate mixtures). The parameters to be analyzed included the yield of biomass; the yield, synthesis rate, and composition of copolymers; the activity of the key enzymes of polyhydroxyalkanoate (PHA) synthesis -ketothiolase, acetoacetyl-CoA reductase, and PHA synthase); the maximum tolerable concentration of valerate to the bacterium; and the conditions that govern the incorporation of hydroxyvalerate into copolymers. This allowed the relationship between cultivation conditions and the proportion of monomers in the copolymers to be deduced. We were able to synthesize a range of 3HB/3HV copolymers and found that the thermal characteristics and the degree of crystallinity of such copolymers depend on the molar fraction of 3HV.Translated from Mikrobiologiya, Vol. 74, No. 1, 2005, pp. 63–69.Original Russian Text Copyright © 2005 by Volova, Kalacheva.     

The effects of climatic pattern on lichen productivity: Cetraria cucullata (Bell.) Ach. in the arctic tundra of northern Alaska

Summary The climatic control of productivity for two populations of the lichen Cetraria cucullata (Bell.) Ach. growing in the arctic tundra of northern Alaska (70°28N, 157°23W) was examined. Respiratory losses of carbon vary with tissue temperature, tissue water content, and time since wetting. Potential net photosynthetic gains of carbon are affected by photon flux density, tissue temperature, and water content. The net CO₂ exchange responses of populations growing on ridge tundra and on upland tundra differ and these differences reflect possible adaptation to the normal environmental regimes in the two habitats. Simulation of the lichen's net carbon balance using continuous hourly records of photon flux density, temperature, and water content for the unusually dry period June 28 through July 17, 1977 show that lichen biomass is actually lost during climatic regimes leading to frequent but short periods of lichen metabolic activity. This result is confirmed by the negative relative growth rates measured for C. cucullata over the same monitoring period. This observed loss of biomass may be attributable to depletion of carbon reserves to reactivate dormant metabolism without sufficiently long periods favorable for net photosynthetic activity to replenish the lost reserves. These results illustrate that environmental limits exist on the success of the dormancy strategy characteristic of lichen and moss carbon metabolism.     

Proteins as potential bacterial growth inhibitors in foods: Suppression of the activity of water by proteins as determined by NMR relaxation methods

Summary Food microbiologists have long known that suppression of the activity of water,a _w, can retard microbial growth in food systems. Traditionally,a _w, suppression has been achieved by addition of salts or humectants to foods. To limit the amount of preservatives added to food products, studies were initiated to assess the feasibility of using proteins to suppressa _w to a practical value for retarding bacterial growth and to determine the optimum environmental condition for maximizing this effect for milk proteins. New expressions were developed relating observed longitudinal and transverse NMR relaxation rates, in the absence of cross-relaxation, to protein hydration , to the protein activity coefficient, _p, and to the correlation time of the bound water, _c. From _p, the second virial coefficient of the protein,B _o, can be found. By use of andB _o,a _w could then be directly evaluated at any protein concentration. Resulting expressions were tested by²H-NMR relaxation measurements made as a function of protein concentration, for: -lactoglobulin A (the major whey protein) under nonassociating (pH 6.0) and associating (pH 4.65) conditions; and for casein (the major milk protein) in the micellar (with added Ca²⁺) and submicellar (without Ca²⁺) forms. Values ofa _w calculated from these²H-NMR data show that casein, at all the concentrations and temperatures examined, suppressesa _w more than does -lactoglobulin A because of a largerB _o. In turn, micellar casein suppressesa _w to a larger extent than does submicellar casein because of a larger . Extrapolation ofa _w at 4°C to a concentration ten times that in normal milk yields a value, ofa _w of less than 0.95, at whichSalmonella and some strains ofClostridium botulinum no longer grow. These results are in agreement with what is known about storageability of condensed milk. Generalizations regarding the types of proteins and cosolutes to be used for suppressinga _w will be discussed. Structural information on these proteins calculated from _c will also be presented.     

Histochemical study of effects of weak electromagnetic field on structures of the rat midbrain

Histochemical activity of the mitochondrial enzyme cytochrome oxidase (CO) in auditory and non-auditory structures of rat midbrain was studied after exposure to low electromagnetic field (EMF). An increase of the enzyme activity was shown in several midbrain structures of the experimental animals.Translated from Zhurnal Evolyutsionnoi Biokhimii i Fiziologii, Vol. 41, No. 1, 2005, pp. 95–100.Original Russian Text Copyright © 2005 by Krasnoshchekova, Gunko, and Tkachenko.     

The Ribbon of Hydrogen Bonds in the Three-Dimensional Structure of Globular Proteins

We report quantum mechanical computations and experimental evidence which suggest that the backbone conformation of globular proteins depends generally on the conservation of that part of the hydrogen bond network or ribbon which is joined, in general, directly to the backbone and is largely independent of the remainder of this whole network of hydrogen bonds. The familiar hydrogen bonds of the helix and the sheet form about one-half of this ribbon of hydrogen bonds. Both water molecules and hydrogen bonding side chain groups are involved in the formation of the ribbon.This view of the three-dimensional structure of globular proteins in terms of the `molecule' allows us to deal with the non-secondary structure as well as with the familiar secondary structure. It also suggests that the ribbon contains approximately the same number of hydrogen bonds within all three structures – the helix, the sheet and the coil – and that this is the reason for the ease of interconversion of these three structures.The quantum mechanical computations on hydrogen bonding suggest that delocalised water molecules which have substantial mobility are an essential part of the ribbon. This situation arises because the hydrogen bonding groups of the protein molecule are not free to move to optimise the hydrogen bonding geometries as are the oxygen atoms in the waters and ices. Such delocalised water molecules either have high B values or are invisible in the X-ray data and yet are able to form a structure which is as strong as a normal hydrogen bond.The experimental data on the point mutations of the THRI57 residue of the T4 phage lysome provides an initial test of this model. Both the local backbone conformation and the ribbon of hydrogen bonds are conserved throughout all the mutations of residue 157,providing that the delocalised water molecules are accepted as a genuine part of the structure. These mutations include the introduction of hydrocarbon side chains at position 157 when water molecules or other side chain groups take over the formation of the hydrogen bonds.We suggest that, provided steric effects are not important, many point mutations succeed because they leave the ribbon of hydrogen bonds (and so the backbone conformation) largely unchanged.     

The dependence of the antibacterial effect of the polycationic peptide warnerin on the energy state of target cells

The bactericidal effect of the polycationic peptide warnerin, produced by Staphylococcus warneri IEGM KL-1, was found to depend on the energy state of susceptible Staphylococcus epidermidis cells. The pretreatment of these cells with compounds that diminish the proton-motive force of plasma membranes enhanced cell tolerance to warnerin. The components and pH of the membrane proton potential influenced the antibacterial activity of warnerin in different ways. In particular, the antibacterial activity of warnerin decreased when the electric component of the proton-motive force of target membranes declined.__________Translated from Mikrobiologiya, Vol. 74, No. 2, 2005, pp. 166–171.Original Russian Text Copyright © 2005 by Korobov, Titova, Lemkina, Polyudova, Pankova.     

Genotype by environment interaction for growth of Eucalyptus globulus in Australia

This study assessed the genotype by environment (G × E) interaction for diameter growth in 15 Eucalyptus globulus progeny trials in Australia. Single-site analyses revealed significant subrace and family-within-subrace variance in all trials. Across-site subrace () and family () correlations were estimated by linear mixed model analyses of pairs of trials. Using a factor analytic structure for subrace and family random terms in a multi-environment mixed model analysis, best linear unbiased predictions of subrace effects were obtained for each trial. These were then averaged for each of four states (Victoria, Tasmania, South Australia and Western Australia) and across all sites. Statistically significant G × E interaction was detected, and weighted means across states for and were 0.73 and 0.76, respectively. Nevertheless, the three subraces from the Otway Ranges were both fast growing and relatively stable in their ranks over all sites. We evaluated the sensitivity of subraces to changing environmental conditions, on the basis of random coefficient models regressing subrace performance on selected trial climatic variables. The results suggested differential susceptibility of subraces to water, light and (to a less extent) temperature stresses during summer. Moreover, using multivariate techniques to visualize and interpret the across-site correlation structure for subrace effects, we could identify site clusters of reduced G × E interaction related to soil water availability and evaporative demand during summer. A revised site-type classification using these factors should allow a better capture of genetic gains from breeding and deployment.     

Circadian variation of insensible perspiration in man

Body weight loss was measured continuously for 24 hours in lightly clothed subjects at a room temperature of 26°C and relative humidity of 60% using the bed scale (model 33B, James Addison Potter). One male, aged 38 years and four females, aged 22 years served as subjects. Skin temperatures of the chest, thigh, leg and arm were measured every ten min. and mean skin temperature was calculated. Water loss through the skin was estimated by deducting body weight loss due to respiratory gas exchange and respiratory water loss from total weight loss. Respiratory water loss was estimated by using the formula (44-P_a) where _e is the rate of evaporative water loss in the expired air (g/min), the oxygen uptake (L/min STPD) and P_a is the ambient water vapor pressure. Insensible water loss through skin was found to be significantly lower between 2:00–5:00 h than in the daytime. These findings contradict the results that the value of insensible water loss was higher at night than during the day.     

Altered utilization patterns of young and old soil C by microorganisms caused by temperature shifts and N additions

To determine if changes in microbial community composition and metabolic capacity alter decomposition patterns of young and old soil carbon pools, we incubated soils under conditions of varying temperature, N-availability, and water content. We used a soil from a pineapple plantation (CAM; ¹³C litter = –14.1) that had previously been under tropical forest (C3; ¹³C soil carbon = –26.5). Forest derived carbon represented 'old' carbon and plantation inputs represented 'new' carbon. In order to differentiate utilization of young (< 14 years) and old (> 14 years) soil carbon, we measured the ¹³C of respired CO₂ and microbial phospholipid fatty acids (PLFAs) during a 103 day laboratory incubation. We determined community composition (PLFA and bacterial intergenic transcribed spacer (ITS) analysis) in addition to carbon degrading and nutrient releasing enzyme activities. We observed that greater quantities of older carbon were respired at higher temperatures (20 and 35°C) compared to the lower temperature (5°C). This effect could be explained by changes in microbial community composition and accompanying changes in enzyme activities that affect C degradation. Nitrogen addition stimulated the utilization of older soil carbon, possibly due to greater peroxidase activity, but microbial community composition was unaffected by this treatment. Increasing soil moisture had no effect on the utilization of older SOM, but enzyme activity typically declined. Increased oxidative enzyme activities in response to elevated temperature and nitrogen additions point to a plausible mechanism for alterations in C resource utilization patterns.     

Effect of chaotropic agents on the structure-function of recombinant acylpeptide hydrolase

Acylpeptide hydrolase, a new class the serine-type peptidase, belongs to the , hydrolase group of proteins. The tetrameric enzyme showed varying degree of stability in the presence of 1–8 M urea. The enzyme displayed about 15% of its original activity when treated with 8 M urea for 1 h at 25°C. Complete recovery of the enzyme activity was observed on dialysis or dilution (50-fold) of the denatured enzyme. However, complete abolition of the enzyme activity was observed in the presence of 1 M GnHCl. Dialysis of the 1 M GnHCl-treated enzyme resulted in 15–20% recovery of the enzyme activity. The fluorescence emission spectra of the native enzyme at 337 nm showed a red shift up to 16 nm in 8 M urea and 18 nm in the presence of 4 M GnHCl. Native enzyme during far-UV circular dichroism spectroscopy exhibited predominantly -sheet structure. The enzyme lost its secondary structure at urea concentrations of 2 M and higher, whereas the tertiary structure was minimally perturbed below 4 M urea. However, in 1 M GnHCl the enzyme lost both its secondary and tertiary structures and the enzyme was found to dissociate into monomers of 70 kDa. Both monomeric and dimeric species were observed after 24-h dialysis of the enzyme denatured with GnHCl indicating the reassociation process. Both monomer and dimers forms recovered after dialysis were active.     

Characterization of Zn2+-binding nuclear proteins present in the myocardium

Nonhistone nuclear proteins were isolated from 3–5 day old neonatal as well as 3 month-old adult myocardium. The nuclear proteins were separated and analyzed by two-dimensional polyacrylamide gel electrophoresis. Using a blot transfer technique equilibrated with⁶⁵Zn²⁺, at least four polypeptides exhibited Zn²⁺-binding activity over the spectrum of nonhistone nuclear proteins. A protein with a molecular weight of 68kDa pI7.8, which has been characterized for its involvement in nucleosome structure, consistently binds Zn²⁺ in both the neonatal and adult myocardium. This nuclear protein has now been further characterized by partial amino acid microsequencing. It was found that this novel polypeptide is distinct from the pore-complex lamina proteins. Three other polypeptides with M90kDa, pI7.8, M68kDa, pI6.5 and M35 kDa, pI7.5 exhibited increased Zn²⁺-binding activity in neonatal myocardium as compared to adult myocardium. Together with results from our previous studies, this study provides the first evidence implicating Zn⁺⁺-binding nuclear proteins in the processes of growth and differentiation of myocardial development. (Mol Cell Biochem121: 175–179, 1993)