Molecular biomarkers of the physiological state of mitten crab Eriocheir japonica (de Haan, 1835) in the estuarine zones of Peter the Great Bay (Sea of Japan)

The mitten crab Eriocheir japonica (de Haan, 1835) is used as an indicator species for the biochemical monitoring of different estuarine zones in Peter the Great Bay (Sea of Japan). The following molecular biomarkers are determined in the gills and hepatopancreas of the crabs: the activity of biotransformation of enzyme glutathione-S-transferase; antioxidative enzymes, superoxide dismutase, and catalase; and reduced glutathione concentration and lipid peroxidation level measured as malondialdehyde. The state of biochemical indicators testify to the good physiological condition of crabs from estuaries of Shkotovka and Sukhodol rivers and to a depressed physiological condition for crans from the Tesnya River. The latter crabs have lower activity of catalase but higher glutathione-S-transferase activity and lipid peroxidation level. Using the data of molecular-biomarker determination, the integral biochemical index was calculated, which made it possible to rank the estuaries by the extent of adverse effects on the biota. Researching the functional condition of the indicator species allows one to estimate and predict the biota state under anthropogenic impact.     

Comparative effects of limited tryptic hydrolysis on physicochemical and structural features of seed 11S globulins

The effect of the limited proteolysis by trypsin on selected seed storage 11S globulins (broad bean and pea legumins, glycinin and helianthinin) was studied by high-sensitive differential scanning calorimetry, fluorescence spectroscopy and analysis of proteolysis kinetics. Different behaviour of glycinin and helianthinin, on one hand, and broad bean and pea legumins, on the other, were observed: in the first group changes in the physicochemical characteristics of the proteins due to their limited proteolysis are more pronounced in comparison with the second one, in relation with the extent of primary structure modifications. The differences observed have been evaluated in relation with the amino acid sequence features of the four 11S globulin studied and agree with the literature data concerning the protein structural changes in the course of the limited proteolysis.     

A Method for Isolation of Chloroplast DNA and Mitochondrial DNA from Sunflower

We present a method for isolation of chloroplast and mitochondrial DNA from sunflower seedlings. The protocol includes: organelle isolation, deoxyribonuclease treatment, lysis, deproteinisation and a final DNA purification with sodium dodecyl sulphate and potassium acetate. The organelle DNA yield is 5–10 micrograms per gram of tissue and the DNA is fully restrictable. The technique is inexpensive and appropriate for the isolation of multiple samples of organelle DNA from a small amount of tissue.     

A study of dilute aqueous solutions of humic acids by scanning microcalorimetry

It has been found by reversed-phase chromatography that humic acids obtained from vermicomposts of different duration of vermicomposting consist of a hydrophilic and a hydrophobic fractions, the hydrophobic fraction having a substantially lower content of charged, probably carboxylic, groups. A change in the sign of the temperature dependence of the heat capacity of dilute aqueous solutions of humic acids at ∼58°C has been found by differential scanning microcalorimetry, which indicates an increase in the hydration of hydrophobic groups. A jump-wise increase in heat capacity in the temperature range from 86 to 90°C was also found, which is perhaps due to hydration of hydrophobic groups in the interior of “micelles“, because of “devitrification” of the hydrophobic nucleus of micelle-like structures. It was shown that increasing the duration of vermicomposting leads to an increase in the relative content of the hydrophobic fraction of humic acids and in the cooperativity of the thermodynamic transition, which manifests itself as the jump of heat capacity, which probably results from the increase in the “micelle” size.     

Functional evolution of two subtly different (similar) folds

Background

The function of proteins is a direct consequence of their three-dimensional structure. The structural classification of proteins describes the ways of folding patterns all proteins could adopt. Although, the protein folds were described in many ways the functional properties of individual folds were not studied.

Results

We have analyzed two β-barrel folds generally adopted by small proteins to be looking similar but have different topology. On the basis of the topology they could be divided into two different folds named SH3-fold and OB-fold. There was no sequence homology between any of the proteins considered. The sequence diversity and loop variability was found to be important for various binding functions.

Conclusions

The function of Oligonucleotide/oligosaccharide-binding (OB) fold proteins was restricted to either DNA/RNA binding or sugar binding whereas the Src homology 3 (SH3) domain like proteins bind to a variety of ligands through loop modulations. A question was raised whether the evolution of these two folds was through DNA shuffling.     

The role of lipids during exposure of mutant cells of Candida tropicalis D-2 to heterologous DNA after treatment with calcium cations

It was shown that treatment of mutant cells of Candida tropicalis D-2 strain with deficiency for histidine and respiration Ca2+ ions leads to increase in the number of revertants at the action of heterologous DNA. The effect of preliminary treatment with Ca2+ ions depends on the time of their action, the number of intracellular lipids, the nature of DNA and temperature of treatment.     

Isolation and properties of the protoplasts of Streptomyces erythraeus

The paper is concerned with development of conditions for cultivation of the erythromycin-producing organism and preparation and maintenance of its stable viable protoplasts. Optimal conditions for the culture growth and protoplasting were developed. Two-stage cultivation of the organism on media PB and S provided dense diffuse or diffuse local growth characterized by low differentiation and higher homogenicity. The incubation time at stage I was 66 hours and that at stage II was not more than 24 hours at respective temperatures. The culture was incubated on a shaker in the presence of glycine at the minimum concentration. The presence of glycine in the medium altered the culture cell walls which was evident from changing of staining by Gram from + to +/- . Treatment of such a culture with lysozyme for 30 minutes provided formation of up to 2.10(9) protoplasts per 1. ml. It is possible to maintain the protoplasts in frozen state at -20 degrees C in medium P for 1 month. Under such storage conditions the titer of the viable protoplasts as compared to the initial one decreased only 2-fold after the one-month storage.