A DNA-nicking activity was detected in the sera of patients with various autoimmune pathologies and was shown to be a property of autoantibodies. The DNA hydrolyzing activity, which was purified by affinity and high-performance liquid chromatography, corresponded in size to immunoglobulin M (IgM) and IgG and had a positive response to antibodies to human IgG. The DNA hydrolyzing autoantibodies were stable to acid shock and yielded a DNA degradation pattern that was different from that of deoxyribonuclease (DNase) I and blood DNase.

Alzheimer's disease (AD) is a progressive neurodegenerative disease and the leading cause of senile dementia in the United States. Accumulation of amyloid-b (Ab) and the effects of this peptide on microglial cells contribute greatly to the etiology of AD. Experiments were carried out to determine whether the panselective s-receptor agonist afobazole can modulate microglial response to the cytotoxic Ab fragment, Ab [25][26][27][28][29][30][31][32][33][34][35] . Treatment with afobazole decreased microglial activation in response to Ab, as indicated by reduced membrane ruffling and cell migration. The effects of afobazole on Ab 25-35 -evoked migration were concentration dependent and consistent with s-receptor activation. When afobazole was coapplied with either BD-1047 [N-[2-(3,4-dichlorophenyl)ethyl]-N-methyl-2-(dimethylamino)ethylamine dihydrobromide] or rimcazole, which are s-1-and s-2-selective antagonists, respectively, the inhibition of Ab 25-35 -induced migration by afobazole was reduced. Prolonged exposure of microglia to Ab 25-35 resulted in glial cell death that was associated with increased expression of the proapoptotic protein Bax and the death protease caspase-3. Coapplication of afobazole with Ab 25-35 decreased the number of cells expressing both Bax and caspase-3 and resulted in a concomitant enhancement in cell survival. Although afobazole inhibited activation of microglia cells by Ab [25][26][27][28][29][30][31][32][33][34][35] , it preserved normal functional responses in these cells after exposure to the amyloid peptide. Intracellular calcium increases induced by ATP were depressed in microglia after 24-hour exposure to Ab [25][26][27][28][29][30][31][32][33][34][35] . However, coincubation in afobazole returned these responses to near control levels. Therefore, stimulation of s-1 and s-2 receptors by afobazole prevents Ab [25][26][27][28][29][30][31][32][33][34][35] activation of microglia and inhibits Ab 25-35 -associated cytotoxicity, suggesting that afobazole may be useful for AD therapeutics.

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Recombinant interferon-β1b (IFN-β1b) is an effective remedy against multiple sclerosis and other diseases. However, use of small polypeptide (molecular weight is around 18.5 kDa) is limited due to poor solubility, stability, and short half-life in systemic circulation. To solve this problem, we constructed two variants of PASylated IFN-β1b, with PAS sequence at C- or N-terminus of IFN-β1b. The PAS-modified proteins demonstrated 4-fold increase in hydrodynamic volume of the molecule combined with 2-fold increase of in vitro biological activity, as well as advanced stability and solubility of the protein in solution as opposed to unmodified IFN-β1b. Our results demonstrate that PASylation has a positive impact on stability, solubility, and functional activity of IFN-β1b and potentially might improve pharmacokinetic properties of the molecule as a therapeutic agent.

Blood sera of patients with autoimmune diseases soleroderma @cl), systemic lupus erythematosus (SLE), and rheumatoid arthritis (RA) have been shown to yield a specific immune response to topoisomerase I, the product of expression of a cDNA fragment cloned into lZgtl1 and monoclonal antibodies (MAB) to the enzyme. The 'topoisomerase test' is no1 absolutely specific for Scl. The stable positive response of autoimmune sera to anti-topoisomerase monoclonal antibodies bus a specific character and is associated with the interaction of the Fab fragment of MAB krith the IgG fraction of autoimmune serum. The response observed indicates the induction of anti-idiotypic antibodies against topoisomerase. The anti-idiotype, isolated by HPLC and affinity chromatography demonstrated the following functional activities: (i) the lnnnunologicol reaction against DNA; (ii) high-affinity DNA-binding with topoisomernse-s@lk consensus; (iii) ability to compete with the native enzyme for biding with DNA and MAB to topoisomerase; (iv) immunological reaction against MAB to topoisomerase. Autoimmunity; Topoisomcrase I; Antiidiotypic antibody; Fusion protein; MPLC of autoimmune sera Production of specific antibodies against various physiologically active compounds, their precursors, transient state analogs and biopolymers has recently gained a new stimulating aspect and entered another phase due to the development of a special field of immunochemistry and enzymology, viz. the catalysis by antibodies or 'abzymcs' [l,Z] which has wide prospects for use both in fundamental research and for practical purposes.Marked progress in the new field of abzymes has been so far achieved regarding only a limited number of biologically significant chemical transformations and mostly concerns chemistry of proteolysis 131. To our knowledge, for example, one of the most interesting objects, DNA, has not been considered yet as an antibody substrate. Many difficulties in this field are connected with the problem ofchoosing an adequate model for DNA chemical transformations and a design of the corresponding transient states.

In order to create an active pharmaceutical substance of the drug with prolonged action the modification of recombinant human granulocyte colony-stimulating factor GCSF (filgrastim) with polyethylene glycol (PEG, M 21.5 kDa) was conducted. A method for preparation of PEG-filgrastim designed for the development and scaling-up of the technological process of production was described. Modification of proteins with PEG was performed by selective covalent attachment of the molecule alpha-methyl-PEG-propionaldehyde to the alpha-amino group of the N-terminal methionine amino acid residue of the recombinant GCSF. The conditions of the reaction, which provide the desired product yield at least 85% of the total protein, also high protein concentration in the reaction mixture (more than 9 mg/mL) and reduce consumption of PEG in terms of terminal alpha-amino group of the protein was chosen. The data of RP HPLC and MALDI-mass spectrometry showed that the produced drug modified by the N-terminal residue and contains no more than 10% of products with a high degree of modification.

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