[The obtaining and analysis of physiological activity of secreted proteins of Noggin family].

We have developed methods for producing recombinant proteins of Noggin family (Noggin1 and Noggin2 of the Xenopus laevis frog) that can interact with BMP factors of TGF-beta superfamily. The genetic constructs which allow one to effectively obtain Noggin1 and Noggin2 from synthetic mRNA microinjected into Xenopus laevis early embryos, as well as in the prokaryotic expression system, were generated. The obtained proteins contain three Myc-tag epitopes on their N-terminus. This allow one to compare the expression levels of Noggin1 and Noggin 2 constructs, to purify them on the affine immunosorbent and to show the activity of Noggin proteins by analyzing their ability to bind BMP4 factor TGF-beta surperfamily by co-immunoprecipitation.

[Expression of the catalytic antibodies in eukaryotic systems].

Expression of recombinant antibodies in mammalian cells is one of key problems in immunobiotechnology. Alternatively, expression of a broad panel of antibodies and of their fragments may be effectively done in yeast cells. We obtained expression strains of the methylotrophic beast Pichia pastoris producing single chain human catalytic antibody A17 (A.17scFv), Fab-fragment (A.17Fab) and full-size light chain (A.17Lch). These antibodies were characterized in terms of functional activity. The capacity to specifically bind and transform organophosphorus compounds has been demonstrated for A.17scFv and A.17Fab. The loss of activity of the antibody light chain when expressed alone indicates that the active site is formed by both heavy and light chains of the antibody. We determined the reversible constant Kd and the first order constant (k2) of the reaction of the covalent modification of A.17scFv and A.17Fab by irreversible inhibitor of the serine proteases p-nitrophenyl 8-methyl-8-azobicyclo[3.2.1]phosphonate (Phosphonate X). Calculated values indicate that activity of the antibodies expressed in yeast is similar to the full-size antibody A17 and single chain antibody A.17 expressed in CHO and E. coli cells respectively.

[Direct incorporation of 18O isotopes into peptides and proteins for quantative analysis by mass spectrometry method].

The method of direct introduction 18O isotopes in peptides and proteins carboxylic groups through the exchange with H218O in the presence of TFA is shown. The isotope label is steady enough in awide range of pH. Because the labeled compounds retain their physical and chemical characteristics, they can be used as an internal standard in quantitative determination of authentic compounds in the analyzed sites by mass spectrometry methods. The technique may be applicable for quantitative analysis of peptides and proteins in biological environments, for quantitative study of the kinetics of metabolism and enzymatic activity. For polypeptides and proteins the quantitative analysis is combined with trypsinolysis. If necessary, the isotope label may be introduced simultaneously in all peptides and proteins control bioassays, making it suitable for use as a standard for the comparative analysis of experimental bioassays.

[Functional degradation of myelin basic protein. Proteomic approach].

Proteolytic degradation of autoantigens is of prime importance in current biochemistry and immunology. The most fundamental issue in this field is the functional role of peptides produced when the specificity of hydrolysis changes during the shift from health to disease and from normal state to pathology. The identification of specific peptide fragments in many cases proposes the diagnostic and prognostic criterion in the pathology progression. The aim of this work is comparative study of the degradation peculiarities of one of the main neuroantigen, myelin basic protein by proteases, activated during progress of pathological demyelinating process, and by proteasome of different origin. The comparison of specificity of different studied biocatalysts gives reason to discuss the critical change in the set of myelin basic protein fragments capable to be presented by major histocompatibility complex class I during neurodegeneration, which can promote the progress of autoimmune pathological process.

[Comparative proteomic characteristic of Mycoplasmas (Mollycutes)].

Saturating proteome identification and the study of post-translational protein modifications of Acholeplasma laidlawii using combination of single- and two-dimension gel electrophoresis followed by mass-spectrometry analysis have been carried out. Results were compared to the earlier identified proteome of Mycoplasma gallisepticum. It was found that M. gallisepticum and A. laidlawii express 61 and 58% of the annotated ORFs respectively. All subunits of DNA-polymerase III were identified during our study which indicates that our methods can detect single copies of a given protein per cell. Metabolic pathways of the respective mycoplasmas were compared further in this work.

[Systems biology approach to the functional role of enzymatic modification of bacterial ribosome].

In this work we describe methodology for studying the role of bacterial ribosome modification in the regulation of gene expression. Ribosomal components modification influences translation efficiencies of certain mRNAs. Proteome analysis allows us to identify cellular protein composition change caused by ribosome modification gene knockout. Particular stage of gene expression responsible for certain protein concentration change could be found using reporter constructs. After identification of mRNA species, whose translation is influenced by ribosome modification we can determine exact mRNA region responsible for the observed changes. The developed methodology can be applied for studying other translational control mechanisms.

[Identification in the rat olfactory epithelium new subgroup YM-1 chitinase-like protein].

Novel protein with a molecular mass of ~43 kDa from rat olfactory epithelium in pathophysiological conditions was discovered. Its amino acid sequence and affiliation with the family 18 glycohydrolase subgroup of chitinase-like proteins YM-1 were determined.

[Detection and identification of the tumor-associated antigens in the fraction enriched with plasma membranes of the Zajdela hepatoma cells].

Tumor-associated antigens 45, 57, 80 and 130 kDa were detected using tumor-specific rabbit immune serum in the fraction enriched with plasma membrane of the rat Zajdela hepatoma cells and isolated on the immunosorbent. Revealed proteins were identified as integrin beta-1, ecto-nucleotide pyrophosphatase/phosphodiesterase-3 (E-NPP3), basigin, epithelial cell adhesion molecule (EpCAM), alpha-fetoprotein (AFP) and protein chaperones--glucose-regulated protein 78 (GRP78) and protein disulfide-isomerase (PDI) A1 by mass spectrometry technique. Functions and characteristics of these proteins in tumor cells and some aspects of the Zajdela hepatoma cells origin are discussed.

[New protein vectors based on an alpha-fetoprotein fragment for targeted DNA delivery into cancer cells].

A human alpha-fetoprotein fragment (AFP) modified with oligocationic homologs of nuclear localization signal was used to construct new target cell-selective DNA-carrier proteins. The new recombinant vectors containing C- or N-terminal polynucleotide-binding domains are able to form stable complexes with single- or double-stranded oligonucleotides and plasmid DNA. Using flow cytometry and fluorescent microscopy, it was shown that such nucleoprotein complexes can be selectively internalized in target cells receptors superexpressing AFP receptors. The results obtained are important both for understanding mechanisms of formation of DNA-protein complexes and for studying their interaction with intracellular molecular targets. The new proteins can be used as a tool for the development of highly selective and efficacious gene-selective antitumour drugs.

[Flu virion as a substrate for proteolytic enzymes].

The proteolysis of flu virions of the strain A/Puerto Rico/8/34 (subtype H1N1) by enzymes of various classes was studied to develop an approach to the study of the structural organization and interaction of the basic protein components of the virion environment: hemagglutinin (HA), transmembrane homotrimeric glycoprotein, and matrix protein M1 forming a layer under the lipid membrane. Among the tested proteolytic enzymes and enzymic preparations (thermolysin, trypsin, chymotrypsin, subtilisin Carlsberg, pronase, papain, and bromelain), the cysteine proteases bromelain and papain and the enzymic preparation pronase efficiently deleted HA ectodomains, while chymotrypsin, trypsin, and subtilisin Carlsberg deleted only a part of them. An analysis by MALDI TOF mass spectrometry allowed us to locate the sites of HA hydrolysis by various enzymic preparations. Bromelain, papain, trypsin, and pronase split the polypeptide chain after the K177 residue located before the transmembrane domain (HA2 185-211). Subtilisin Carlsberg hydrolyzed the peptide bond at other neighboring points: after L178 (a basic site) or V176. The hydrolytic activity of bromelain measured by a highly specific chromogenic substrate of cysteine proteases Glp-Phe-Ala-pNA was almost three times higher in the presence of 5 mM beta-mercaptoethanol than in the presence of 50 mM. However, the complete removal of exodomains of HA, HA, and low-activity enzyme by the HA high- and low-activity enzyme required identical time intervals. In the absence of the reducing reagent, the removal of HA by bromelain proceeded a little more slowly and was accompanied by significant fragmentation of protein Ml1. The action of trans-epoxysuccinyl-L-leucylamido)butane (E-64), a specific inhibitor of cysteine proteases, and HgCl2 on the hydrolysis of proteins HA and M1 by bromelain was investigated.

[Photoactivated analogues of the initiating substrates of RNA polymerase II based on arylazide derivatives of NTP gamma-amidophosphate: synthesis and chemical and photochemical reactions of functional groups].

Photoactivatable derivatives Ar-NH-(CH2)n-NHpppB (where Ar = p-azidophenyl (A1), 5-azido-2-nitrobenzoyl (A2), or 4-azido-2,3,5,6-tetrafluorobenzoyl (A3) group; B = Ado or Guo; n = 2, 3, or 4) were synthesized. The phosphoroamidate bond stability was found to depend on the structure of both the heterocyclic and the photoactivatable groups. The derivative with A3, Ado, and n=3 is hydrolyzed with regeneration of aryl azide and ATP, whereas the other derivatives are stable in aqueous solutions. The photoanalogues with A1 and A2, B = Ado, and n = 2 or 4 were found to behave as initiating substrates toward the RNA polymerase II from Saccharomyces cerevisiae under the conditions of specific transcription initiation and control of the adenovirus late promoter. The photolysis of N-(4-azidophenyl)-1,4-diaminobutane and N-(5-azido-2-nitrobenzoyl)-1,3-diaminopropane, two functional fragments of the photoaffinity reagents, in aqueous solutions was established to result in the formation of p-benzoquinone diimine and p-nitro-N-arylhydroxylamine derivatives, respectively. The arylhydroxylamine derivatives undergo a number of transformations in aqueous solution leading to nitroso derivatives. We concluded that it is these nitroso derivatives (products of nitrene transformation, rather than the nitrene itself) that may modify proteins with reagents containing p-nitrophenylazide fragment.

[Interaction of laminin with the plasma membrane components of ascitic Zajdela hepatoma cells].

The laminin affinity chromatography was used for isolating laminin-binding proteins from the plasma membrane of Zajdela hepatoma cells synthesizing laminin. These were components with mol. weights about 80, 67, 60, 55, 52, 48 and 43 kDa. The isolation of laminin integrin receptors from plasma membranes of Zajdela hepatoma cells in the presence of MnCl2 detected only a protein with mol. weight about 80 kDa in EDTA-elution conditions. This protein was identified by mass spectrometry method as the 78 kDa glucose-regulated protein precursor (GRP78). It belongs to the family of 70 kDa heat shock proteins, recently GRP78 was reported to be localized on the surface of different cell types, including hepatocytes.

Study of the chemical structures of the photo-cross-linking products between Tyr and the 5-azido-2-nitrobenzoyl residue.

Irradiation of N-(tyrosyl)-N'-(5-azido-2-nitrobenzoyl)-1,2-diaminoethane (I) initiates chemical reactions that lead to different products depending on the experimental conditions. All of these products are attributed to the reactions of triplet 4-nitrobenzoyl nitrene (4NBN). The reactions of triplet 4NBN with the tyrosyl residue result in the formation of two distinct products: compound II, which is unstable in aqueous solution, and the stable compound cyclo-[1-(4'-nitro-3'-benzoyl)-2-(aminotyrosyl)-N,N'-ethylenediami ne] (III). The formation of II is detected only in aerobic conditions. The unstable photoproduct II converts almost completely into compound III when its solution is concentrated. The photoproducts II and III have absorption spectra that are close to those of the photolabelled peptides. This finding is important for speculating about the chemical nature of the photomodification products of protein tyrosyl residues by the arylazide group.

Long-lived reactive intermediate photogenerated from N-(5-azido-2-nitrobenzoyl)-N'-(D-biotinyl)-1,2-diaminoethane as an affinity reagent to streptavidin.

Irradiation of a complex between N-(5-azido-2-nitrobenzoyl)-N'-(D-biotinyl)-1,2-diaminoethane (I) and streptavidin with light of 313 nm led to the covalent attachment of the photobiotin analogue I to the protein. Streptavidin could also be labelled in the dark with prephotolyzed I. These results indicate that a long-lived reactive intermediate was formed upon irradiation. Moreover, after cleavage of labelled streptavidin with proteinase K this intermediate appears to be covalently attached to the same peptide as the one obtained by direct photoaffinity labelling. An iminosulfurane II derived from the reaction of biotin sulfur atom with aryl nitrene is responsible for the dark-labelling reaction. The photoproduct II converts in an aqueous solution almost completely into N-(5-amino-2-nitrobenzoyl)-N'-(D-(S-oxo)biotinyl)-1,2-diaminoethane (the half-life of II is 10 days).

[Localization of disulfide bonds in the alpha 1 acidic glycoprotein molecule and study of their effect on ability of the protein to interact with ethidium bromide]. / Lokalization disul'fidnykh sviazei v molekule kislogo glikoproteina alpha1 i issledovanie ikh vliianiia na sposobnost' belka vzaimodeistvovat' s bromistym étidiem.

alpha 1-Acid glycoprotein (orosomucoid) was purified from the human and murine blood sera using phenol deproteinization. As opposed to the murine protein, the human orosomucoid bound the fluorescent dye ethidium bromide but lost this ability after treatment with beta-mercaptoethanol, which breaks disulfide bonds. Disulfide bonds between the Cys23 and Cys165 residues of the human orosomucoid and between the Cys91 and Cys184 residues of the murine orosomucoid were identified.

[Mass spectrometry MALDI TOF for rapid qualitative evaluation of recombinant proteins production in E. coli]. / Mass-spektrometriia MALDI TOF dlia bystroi kachestvennoi otsenki produktsii genno-inzhenernykh belkov v E. coli.

The possible use of MALDI TOF MS for the analysis of Escherichia coli strains producing recombinant proteins was studied. It was shown that the target chimerical proteins might be rapidly detected in the strains.

[The degradation of glycoproteins with lithium borohydride. Isolation and analysis of O-glycopeptides with reduced C-terminal amino acid residue]. / Rasshcheplenie glikoproteinov pod vozdeistviem borgidrida litiia. Vydelenie i analiz o-glikopeptidov s vosstanovlennoi C-kontsevoi aminokisloto i.

By the example of fetuin and a blood-group-specific mucin from porcine stomach, we showed that, under conditions of reductive degradation of glycoproteins with LiBH4-LiOH in 70% aqueous tert-butyl alcohol, the reduction and cleavage of amide bonds occur much faster than the simultaneous beta-elimination of carbohydrate chains O-linked with Ser and Thr residues of the peptide chain. The major degradation products containing the O-linked glycans are the O-glycosylated derivatives of 2-aminopropane-1,3-diol and 2-aminobutane-1,3-diol (the products of reduction of glycosylated Ser and Thr) and the glycopeptides containing 2-4 amino acid residues with reduced C-terminal amino acid. Seventeen homogeneous O-glycopeptides were isolated from the fetuin degradation products by ion-exchange and reversed-phase HPLC. Their structures were determined by MALDI-TOF mass spectrometry and by analyses for amino acids, amino alcohols, and carbohydrates. The application of the reaction for characterization of O-glycans and localization of O-glycosylation sites in O- and N,O-glycoproteins is discussed.

[Determination of "amino acids conflicts" and amino acids substitutions in primary structures of 41 human proteins by use the proteomic technologies].

Proteomic studies of some human tissues and organs (skeletal muscles, myometrium, motor zone of the brain, prostate), and also cultivated myoblasts revealed 41 of 300 identified proteins, in which the present of certain variants of amino acids ("conflicts") was recognized at several positions. Among the 93 registered amino acids "conflicts", seven cases represented the results of the protein polymorphisms caused by corresponding substitution of individual amino acid. Moreover, among prostate proteins the proteomic analysis revealed two isoforms of prostate-specific antigen, formed due to alternative splicing. Thus, our results have shown, that proteomic technologies allow to specify effectively the features of primary structures and to characterize various kinds of polymorphism in many human proteins.

[Age-related changes of albumin and actin of human myocardium].

In the human myocardium tissue, proteomic technologies revealed the products of 2 genes (alpha-actin and albumin), existing as fragments; their appearance and increased contents correlated with age. The age-related variants differ from the mature forms by the absence of N-terminal fragments of the amino acid sequences. In the chronic ischemic heart disease (CIHD), these age-dependent proteins were found in 50% of cases (in the age group 31-40 years), while in the control group such combination was detected only in 10% of the examined individuals. Subsequent studies in this field would probably reveal molecular mechanisms responsible for impairment and/or ageing of the cardiac muscle and also of the adaptation-dysadaptations mechanisms in the CIHD.