[Laboratory tests in the diagnosis of feral herd infections].

Immunological laboratory tests play an important role in establishing the depth of extent of this or that infectious disease. Scheduled immunological monitoring (serological screening) is made to find out whether there are antibodies (Abs) against the causative agents of individual feral herd infections. The immunological examination is aimed at detecting Abs against the pathogens of infectious diseases of bacterial (Ixodes tick-borne borrelioses, tularemia, leptospiroses, human granulocytic anaplasmosis), viral (hemorrhagic fever with renal syndrome, tick-borne viral encephalitis, West Nile fever), and rickettsial (Q-fever) etiologies. The performed serological screening could yield data on the practically widespread of hemorrhagic fever with renal syndrome in the Ulyanovsk Region and show high rates of Abs to Ixodes tick-borne borrelioses (5.75), coxiellosis (3.7%), and human granulocytic anaplasmosis (4.3%).

[Mapping of diagnostically important antigenic regions of major outer membrane protein (MOMP) from Chlamydia trachomatis using recombinant proteins with overlapping structures].

Amino acid sequence of the Chlamydia trachomatis major outer membrane protein (MOMP) was modeled using a series of the recombinant proteins containing six 100 aa fragments of MOMP overlapped in 30 aa. Testing of recombinant antigens in EIA showed that proteins containing MOMP fragments comprising 191-286 and 191-354 aa regions had the greatest activity in the reaction with anti- C. trachomatis positive serum samples. The data obtained allows the conclusion about the possibility of the use of presented recombinant proteins for development of diagnostic test for anti- C. trachomatis antibodies detection to be made.

[Study of the diagnostic potential of various regions of tick-borne encephalitis virus glycoprotien E].

Bioinformation techniques were used to analyze envelope glycoprotein of tick-borne encephalitis virus in order to determine the potential diagnostically significant antigenic clusters. Five selected regions of the amino acid sequence of protein E were retranslated to nucleic sequences, by employing the optimum code for E. coli. The resultant DNA fragments were synthesized by polymerase chain reaction from synthetic oligonucleotides and expressed in E. coli cells. The recombinant antigen replicating the region from 296 to 414 aminoacids demonstrated the most significant antigenic activity. The findings lead to the conclusion that this recombinant protein may be considered as a candidate for the development of a diagnostic assay.

[Structural-dynamic and functional properties of native and modified streptokinase]. / Strukturno-dinamicheskie i funktsional'nye svoistva nativnoi i modifitsirovannoi streptokinazy.

The process of streptokinase modification by a polymer and the dynamics of protein molecules and the polymer in a protein-polymer (dialdehyde dextran, DAD) conjugate were studied with the aid of luminescent methods. Conclusions were drawn on the structure of the protein-DAD conjugate and the selection of optimum conditions for the preparation of modified streptokinase. It is shown that modified streptokinase is more stable to the action of denaturating agents. The interaction between streptokinase and plasminogen activated by it and changes in the streptokinase-plasminogen complex for modified streptokinase were detected.

[Digestion of Luliberine analogues containing D-alanine residue by human gastric juice]. / Rasshcheplenie zheludochnym sokom cheloveka analogov liuliberina, soderzhashchich ostatok D-alanina.

The digestion of surphagone and other luliberine analogues containing residues of D-amino acids by human gastric juice was studied. By means of chromatography and mass spectrometry, these peptides were shown to undergo hydrolysis of the bond formed by D-Ala at the P-1 position, and this hydrolysis was shown to be catalyzed by gastricsin rather than pepsin A. Gastricsin was assumed to be a highly specific protease. The results are in a good agreement with the concept of conformational specificity of proteases towards the natural oligopeptides.

[MALD-MS in the quantitative analysis of peptides and proteins]. / Ispol'zovanie MALDI-MS dlia kolichestvennogo analiza peptidov i belkov.

A modified method of isotope dilution was applied to the quantitative determination of peptides and proteins by MALDI MS at subpicomolar level. The essence of the method consists in the quantitative analysis of the enzymic hydrolysis products rather than the starting compounds. This allows the measurements to be performed at a higher resolution and makes the method independent of the molecular mass of oligopeptides and proteins examined. Fragments obtained by hydrolysis of the same oligopeptide or protein in a known concentration by the same enzyme and labeled with the stable 18O isotope are used as internal standards. The label is introduced by carrying out the hydrolysis in H(2)18O, and the oligopeptide concentration is calculated from the isotope distribution between the labeled and unlabeled hydrolysis products in the mass spectrum. This method was tested in the determination of concentrations of the angiotensinogen (1-14) fragment (oligopeptide), extracellular RNAase from Bacillus amyloliquefaciens (protein) and its protein inhibitor, barstar M. Usefulness of this method in kinetic studies was also demonstrated.

[Fungal aspartic proteinase from Trichoderma viride. Specificity during oligopeptide hydrolysis]. / Gribnaia aspartatnaia proteinaza iz Trichoderma viride. Spetsifichnost' pri gidrolize oligopeptidov.

We isolated, purified, and characterized an aspartic protease from fungus Trichoderma viride. The pH-dependence of the enzyme functioning was determined, and its specificity in the limited proteolysis of insulin and melittin was compared to the specificities of pepsin A and gastricsin. The kinetics of melittin hydrolysis by these enzymes was studied by mass spectrometry.

[Effects of infusion therapy on immunity and calcium contents in patients with stomach cancer]. / Vliianie infuzionnoi terapii na sostoianie immuniteta i soderzhanie kal'tsiia u bol'nykh rakom zheludka.

The humoral factor of non-specific immunity was shown to be inhibited significantly in gastric cancer patients. According to an analysis of immunologic status, phagocytic activity and blood plasma level of lysozymes increased during treatment of stomach cancer, thus pointing to favorable course of postoperative period.