[Highly active fractions of the medicinal leech recombinant destabilase-lysozyme].

From the highly purified but lowly active recombinant protein Destabilas-Lysozyme (Dest-Lys) by use cation-exchange column TSK CM 3-SW chromatography, it was separated non-active fraction IV, contained 90% of protein. Fractions I, II and III, represented proteins with lysozyme and isopeptidase activities. Their lysozyme activity correlates with the activity of natural Des-Lys.

[Catalytic sites of medicinal leech enzyme destabilase-lysozyme (Mldl). Structure-functional correlation].

Based on three-dimensional model of the bifunctional enzyme Destabilase-Lysozyme (mlDL-Ds2) in complex with trimer of N-acetylglucosoamine (NAG)3 the functional role of the stereochemically based group of amino acids (Glu14, Asp26, Ser 29, Ser31, Lys38, His92), in manifestation of glycosidase and isopeptidase activities has been elucidated. By method of site-directed mutagenesis it has been shown that mlDL glycosidase active site includes catalytic Glu14 and Asp26, and isopeptidase site functions as Ser/Lys dyad presented by catalytic residues Lys38 and Ser29. Thus, among the invertebrate lysozymes mlDL presents first example of the bifunctional enzyme with identified position of the isopeptidase active site and localization of the corresponding catalytic residues.

[Lysozyme activity of the salivary gland secretion of the medicinal leech H. verbana, H. medicinalis and H. orientalis].

Salivary gland secretions of three species of the medicinal leech differ in the level of lysozyme peptidoglycan-lysing activity. Using the synthetic fluorogenic substrate, 4-methyl-umbelliferyl tetra N-acetyl-beta-chitotetraosid, the glycosidase activity (as one of peptidoglycan-lysing activities) of salivary gland secretion of three species of the medicinal leech was quantitatively evaluated in comparison with egg lysozyme. It is supposed, that lysozyme activity of the leech secretions is determined not only by 5 isoforms of destabilase-lysozyme, but by some other enzymes which can utilize this substrate.

[An immunological study of secreted human polymeric immunoglobulins' J-peptide tissue specificity].

Contents of J-peptide of secreted human polymeric immunoglobulins may vary considerably with different pathologies, reflecting the state of the adaptive immune system. In this work assessed the content of J-peptide in various tissues of healthy people to use as a baseline for studies related to the change in the content of J-peptide in pathologies.

Destabilase-lysozyme of medicinal leech. Multifunctionality of recombinant protein.

Preparation and purification of a recombinant protein are described along with characteristics of its specific (for ε-(γ-Glu)-Lys and D-dimer substrates) and nonspecific (for L-γ-Glu-pNA) isopeptidase activities; the absence of peptidase function for α-(α-Glu)-Lys substrate is noted. It is shown that the protein exhibits muramidase (cell walls of Micrococcus lysodeikticus) and specific glycosidase activities. The latter was determined towards the fluorogenic substrate 4-methylumbelliferyl-tetra-N-acetyl-β-chitotetraoxide.

Protein-lipid particles of medicinal leech salivary gland secretion; their size and morphology.

The relative location of proteins and lipids in particles of medicinal leech salivary gland secretion (SGS) is revealed for the first time. Their sizes and morphology are described. Using scanning electron microscopy and transmission electron microscopy, it was determined that SGS consists of particles of different sizes and form.

[Comparative analysis of herpes simplex virus thymidine kinase gene expression potentiation via HIV-1 Tat-TAR-system and cancer-specific promoters in p53(+) and p53(-) cells].

Tumor-specific promoters are predominantly active and ensure expression of the gene under control exclusively in cancer cells. However, a low activity of the promoters is an essential disadvantage for their therapy usage. To achieve a higher expression level of the therapeutic gene, herpes simplex virus thymidine kinase (HSV-tk), the Tat-TAR-system being utilized by HIV-1 for increasing own gene expression was developed.

[Polyfunctionality of destabilase, a lysozyme from a medicinal leech].

Experimental data indicating the polyfunctionality of destabilase, a lysozyme from the salivary gland secretion of the medicinal leech, a unique representative of invertebrate lysozymes, were analyzed. The destabilase combines the properties of endo-s-lysyl-y-glutamyl isopeptidase (D-dimer monomerase), lysozyme, and chitinase and simultaneously is a nonenzymatic antimicrobial agent. The polypeptide sequence of lysozyme destabilase is encoded by a family of three genes (Ds1, Ds2, and Ds3).

[Steroids, histamine and serotonin in medicinal leech salivary gland secretions].

Lipids represent 20% of the total weight of dried pool of medicinal leech salivary gland secretion (SGS) received from about 50 individual animals. There were detected steroids, but not pospholipids in SGS lipid fraction. Immunochemiluminescent analysis identified free steroid hormones in SGS: cortisol, progesterone, testosterone, estradiol and dehydroepiandrosterone.

Proteins and peptides of the salivary gland secretion of medicinal leeches Hirudo verbana, H. medicinalis, and H. orientalis.

The protein and peptide composition of medicinal leech salivary gland secretion (SGS) was analyzed in preparations obtained in July from three species--Hirudo verbana, H. medicinalis, and H. orientalis.

[Decrease in expression of human J-chain in lung squamous cell cancer and adenocarcinoma].

Secretory polymeric immunoglobulins (IgA dimers and IgM pentamers) are unique in that, apart from L- and H-chains, they contain J-chains responsible for their oligomerization. These antibodies are part of the local adaptive immune system acting on mucosa membranes of the respiratory and digestive systems as the first protection barrier to potential infectious agents. Secretory polymeric immunoglobulins are produced by highly specific B-cells and actively transported to the surface of mucosa membrane through epithelium cells.

Proteomic analysis methods for characterization of proteins from the salivary gland secretions of the medicinal leech during different seasons.

Salivary gland secretion (SGS) of the medicinal leech Hirudo medicinalis in summer and winter was studied by proteomic analysis methods, and season-associated difference was found in the distribution of fractionated proteins with the same pattern of their positions. Differences were detected for proteins with molecular weights from 15 to 250 kD fractionated by two-dimensional SDS-PAGE and for 2-10- and 10-60-kD proteins analyzed by SELDI-MS. Thirty-two and 20 proteins were detected by MALDI-TOF-MS in the high-molecular-weight fraction of the summer and winter SGS, respectively, isolated from the corresponding two-dimensional electrophoregrams, and this was less than 20% of the total SGS protein.

Antibacterial non-glycosidase activity of invertebrate destabilase-lysozyme and of its helical amphipathic peptides.

Background: Since bactericidal properties of some lysozymes are independent of their glycosidase activity, we have investigated this phenomenon for destabilase-lysozyme (DL) from medicinal leech (Hirudo medicinalis).

Methods: Glycosidase activity was determined on Micrococcus luteus, non-enzymatic antibacterial activity of heat-treated DL and of synthetic peptides alpha1, alpha2 and alpha3 (fragments of its primary structure) on M. luteus, Escherichia coli, Bacillus brevis and Streptomyces chrysomallus.

[Effect of the medicinal leech salivary gland secretion on the state of rat subcutaneous mast cells].

It is firstly showed that the medicinal leech salivary gland secretion (SGS) as a polycomponent system of proteins and low-molecular weight substances, activates rat subcutaneous mast cells in vitro prompting a decrease in the heparin saturation index and increasing some characteristic mast cells morphometric parameters. The same mast cell changes were detected by analysis of some specimens of subcutaneous cellular tissue in the point of skin injured by the leech bite. It is shown that these changes are saved during 3 days.

Recombinant destabilase-lysozyme: synthesis de novo in E. coli and action mechanism of the enzyme expressed in Spodoptera frugiperda.

Destabilase-lysozyme (DL) from salivary gland secretion of the medicinal leech (Hirudo medicinalis) is as a member of the invertebrate lysozyme family, which sharply differs from other lysozyme families. In this study, DL lysozyme function was confirmed during expression of a gene encoding DL in Escherichia coli. Several constructs of the expression vectors pKK OmpA and pET-3A with or without bacterial, leech, or yeast signal peptides (SP) were used.

Protein profiling of the medicinal leech salivary gland secretion by proteomic analytical methods.

Protein diversity of the high molecular weight fraction (molecular mass > 500 daltons) of salivary grand secretion of the medicinal leech Hirudo medicinalis has been demonstrated using methods of proteomic analysis. One-dimensional (1D) electrophoresis revealed the presence of more than 60 bands corresponding to molecular masses ranging from 11 to 483 kD. 2D-electrophoresis revealed more than 100 specific protein spots differing in molecular masses and pI values.

Tissue specificity of enhancer and promoter activities of a HERV-K(HML-2) LTR.

Transient expression of a luciferase reporter gene was used to evaluate tissue-specific promoter and enhancer activities of a solitary extraviral long terminal repeat (LTR) of the human endogenous retrovirus K (HERV-K) in several human and CHO cell lines. The promoter activity of the LTR varied from virtually not detectable (GS and Jurkat cells) to as high as that of the SV40 early promoter (Tera-1 human testicular embryonal carcinoma cells). The negative regulatory element (NRE) of the LTR retained its activity in all cell lines where the LTR could act as a promoter, and was also capable of binding host cell nuclear proteins.

Multiple forms of medicinal leech destabilase-lysozyme.

Earlier, three genes Ds1, Ds2, and Ds3 encoding corresponding destabilase-lysozyme isoforms were identified. However only one form of the enzyme encoded by Ds3 gene coincided with the protein CNBr fragments [Mol. Gen.

The neurite-stimulating activity of components of the salivary gland secretion of the medicinal leech in cultures of sensory neurons.

The effects of components of the salivary gland secretion (proteases and protease inhibitors) of the medicinal leech (Hirudo medicinalis) on the growth of neurites of sensory neurons from chick embryos (10-11 days old) were studied in organotypic cultures. Destabilase and high-molecular-weight bdellin B, (0.01, 0.

The neurite-stimulating influence of components of medicinal leech salivary gland secretions in organotypic culture of spinal ganglia.

The effects of components from medicinal leech (Hirudo medicinalis) salivary gland secretions and the therapeutic agent Piyavit on the growth of chick embryo neurites in organotypic culture were studied. Native destabilase and bdellin A at concentrations of 0.01, 0.

Purification of proteins specifically binding human endogenous retrovirus K long terminal repeat by affinity elution chromatography.

A novel affinity elution procedure for purification of DNA-binding proteins was developed and employed to purify to near homogeneity the proteins recognizing a 21 base pair sequence within the long terminal repeat of human endogenous retroviruses K. The approach involves loading the initial protein mixture on a heparin-agarose column and elution of protein(s) of interest with a solution of double-stranded oligonucleotide containing binding sites of the protein(s). The affinity elution has several advantages over conventional DNA-affinity chromatography: (i) it is easier and faster, permitting to isolate proteins in a 1 day-one stage procedure; (ii) yield of a target protein is severalfold higher than that in DNA-affinity chromatography; (iii) it is not necessary to prepare a special affinity support for each factor to be isolated.

Vascular-platelet and plasma hemostasis regulators from bloodsucking animals.

Saliva of bloodsuckers (leeches, insects, ticks, vampire bats) contains various regulators of some hemostatic stages. This review summarizes information on their structural characteristics and mechanisms of action. Most bloodsuckers are shown to inhibit vascular-platelet hemostasis by blocking collagen-induced platelet adhesion/aggregation.

Fibrinogen-fibrin system regulators from bloodsuckers.

Thrombin inhibitors from bloodsucking leeches and insects that block conversion of fibrinogen to fibrin are considered. Regulatory mechanisms influencing the fibrinogen-fibrin system in leeches include fibrinogen degradation, inhibition of factor XIIIa, and lysis of fibrin clots. The review also summarizes recent data on plasminogen activator from the vampire bat Desmodus rotundus and a role of fibrin as its cofactor.

[Neurite-stimulating activity of secretions from the Hirudo medicinalis salivary gland in cultured sensory neurons].

Components of leech (Hirudo medicinalis) salivary gland secretion (high molecular mass bdelin B, bdellastasin, eglin C, destabilize) were used to investigate their neurotrophic effect on organotypic culture of dorsal root ganglia of the 10-11-day old chicken embryos. Destabilize and high molecular mass bdelin B in concentrations of 0.01, 0.

Separation of monomerizing and lysozyme activities of destabilase from medicinal leech salivary gland secretion.

Destabilase, endo-epsilon-(gamma-Glu)-Lys-isopeptidase, was prepared from the salivary gland secretion of the medicinal leech (Hirudo medicinalis). The secretion prepared by the known method of Rigbi et al. (1987) (secretion-K) lacks the destabilase-characteristic highly specific isopeptidase activity (the D-dimer-monomerizing activity) because of its degradation by proteolytic activity (the substrate of Glp-Ala-Ala-Leu-pNA) due to contamination with leech intestinal channel contents.