Interaction of chitosan and its derivatives with proteins of animal blood at blood pH relevant conditions is of a particular interest for construction of antimicrobial chitosan/protein-based drug delivery systems. In this work, the interaction of a series of N-reacetylated oligochitosans (RA-CHI) having M of 10-12 kDa and differing in the degree of acetylation (DA 19, 24, and 40 %) with bovine serum albumin (BSA) in alkalescent media is described in first. It is shown that RA-CHI forms soluble complexes with BSA in solutions with pH 7.
View Article and Find Full Text PDFThe interaction between carboxymethyl cellulose and partially reacetylated chitosan soluble in acidic and alkaline aqueous media is studied by light scattering and isothermal titration calorimetry in a wide pH range. It is shown that the formation of polyelectrolyte complexes (PEC) can occur in the pH range of 6-8, while this pair of polyelectrolytes loses the ability to complexation upon transition to a more alkaline medium. The revealed dependence of the observed enthalpy of interaction on the ionization enthalpy of the buffer indicates the participation of proton transfer from the buffer substance to chitosan and its additional ionization in the binding process.
View Article and Find Full Text PDFThe skp gene of Yersinia pseudotuberculosis was expressed without its signal sequence in Escherichia coli BL21(DE3) cells. The recombinant protein Skp accumulated in soluble form in the cytoplasm of the producer strain. The protein was isolated and characterized: the molecular weight, isoelectric point, N-terminal amino acid sequence (20 amino acid residues), and the content of the secondary structure elements were determined.
View Article and Find Full Text PDFVestn Dermatol Venerol
February 1990
Increased levels of circulating immune complexes (CIC) have been revealed in 156 patients suffering from erysipelas and chronic eczema, 109 of these with frequent recurrences of erysipelatous inflammation, during all periods of the disease. The maximal rises of CIC levels have been associated with a combination of erysipelas relapse with eczema exacerbation, with the most pathogenic medium- and low-molecular complexes, making up together 80.4 +/- 4% of CICs, predominating in the blood.
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