The characteristics of antibodies of mice immunized by human unconventional myosin 1c.

Specific antibodies produced against a protein of interest are invaluable tools for monitoring the protein structure, intracellular location and biological activity. Inoculation of murine lymphoma cells into the peritoneal cavity of immunized mice provides generation of ascitic fluid containing a significant amount of antibody with desired antigen specificity. Here we demonstrated that the intraperitoneal administration of murine lymphoma NK/Ly cells in mice immunized with 48 kDa isoform of human blood serum unconventional myosin 1c leads to generation of ascitic fluid that contained specific IgG-antibodies.

Proteolytic activity of IgGs from blood serum of Wistar rats at experimental rheumatoid arthritis.

The aim of this work was to study the proteolytic activity of IgGs purified from blood serum of Wistar rats at experimental rheumatoid arthritis (ERA) induced by an injection of bovine collagen of type II. Twenty rats were immunized with a preparation of bovine collagen II (Sigma-Aldrich, USA) in the presence of complete Freund's adjuvant. ERA development was determined by inflammation in limbs of treated animals.

Detection and characterization of IgG- and sIgA-Abzymes capable of hydrolyzing histone H1.

Immunoglobulins IgG and sIgA actively hydrolyzing histone H1 have been detected on analyzing proteolytic activity of antibodies isolated by chromatography on Protein A-agarose from blood serum of patients with multiple sclerosis and from colostrum of healthy mothers. These antibodies hydrolyze other histones less actively and virtually failed to cleave lysozyme of chicken egg. By gel filtration at acidic pH and subsequent analysis of protease activity of chromatographic fractions, it was shown that IgG and sIgA molecules were responsible for hydrolysis of histone H1.

Adaptor protein Ruk1 forms protein-protein complexes with endonuclease activity in HEK293 cells.

The structural and functional organization of the adaptor protein Ruk(1) is characterized by the presence of three SH3-domains at the N-terminus followed by Pro- and Ser-rich sequences and a C-terminal coiled-coil region. Multiple modules in the Ruk(1) structure involved in protein-protein interactions can provide for formation of ligand clusters with varied properties and subcellular location. To study the nature and biological role of such complexes, the recombinant protein Ruk(1) with a Glu-epitope at the C-terminus (Ruk(1) Glu-tagged) was purified from transfected HEK293 cells by affinity chromatography on protein G-Sepharose with covalently conjugated anti-Glu-tag antibodies.

Human anti-DNA secretory immunglobulins A possess endonuclease activity and they are able to cause the destruction of nuclear chromatin in vitro.

sIgA possessing ability to hydrolyse plasmid DNA to linear forms was purified from human milk by sequential chromatography on protein A-sepharose, DEAE-Fractogel and DNA-cellulose. It was discovered that incubation of sIgA with nuclei of porcine embryo kidney cells permeabilized by Triton X-100 causes formation of electrophoretically mobile forms of nuclear nucleic acids and inhibition of phosphorylation of nuclear proteins. We suppose that sIgA possessing affinity to DNA and endonuclease activity can cause degradation of cell nuclear chromatin.