High Production of Neuraminidase by a Vibrio cholerae Non-O1 Strain--the First Possible Alternative to Toxigenic Producers.

Vibrio cholerae neuraminidase (VCNA) is widely used in biochemical and medical research, in processes for preparing homogenous sialoconjugates, and in the pharmaceutical industry. Its production by non-toxigenic strains is quite desirable, in order to avoid the expensive safety measures. Here, we report the first method for highly effective production of a novel, purified V.

Biochemical studies on the production of neuraminidase by environmental isolates of Vibrio cholerae non-O1 from Bulgaria.

Neuraminidase is a key factor in the infectious process of many viruses and pathogenic bacteria. The neuraminidase enzyme secreted by the etiological agent of cholera - Vibrio cholerae О1 - is well studied in contrast with the one produced by non-O1/non-O139 V. cholerae.

Erysipelothrix rhusiopathiae neuraminidase and its role in pathogenicity.

The role of the enzyme neuraminidase in pathogenicity of the bacillus Erysipelothrix rhusiopathiae was studied. Different substances with low and high molecular weight were tested as inducers of E. rhusiopathiae neuraminidase biosynthesis.

Purification and characterization of a novel sialidase from a strain of Arthrobacter nicotianae.

The nonpathogenic strain Arthrobacter nicotianae produces two sialidase isoenzymes, NA1 and NA2, with molecular masses of 65 kDa and 54 kDa, respectively, as determined by 10% SDS-polyacrylamide gel electrophoresis. NA1 and NA2 exhibit maximum activities at pH 4 and 5, and both show clear thermal optima at 40 degrees C. They are stable at temperatures up to 50 degrees C.

[Biochemical research on the neuraminidase of Erysipelothrix rhusiopathiae].

Purified neuraminidase preparation from Erysipelothrix rhusiopathiae is studied biochemically. The main physicochemical characteristics of the enzyme are determined: molecular mass, isoelectric point, electrophoretic mobility, chemical nature, UV spectrum, substrate specificity, etc. The obtained data are compared to those for other bacterial neuraminidases.

[The immunomodulating properties of a glucomacropeptide from whey. I. The stimulation of resistance in mice].

The immunomodulating effect on mice of three products glucomacropeptides obtained from whey with different carbohydrate and peptide components has been studied. After the preliminary application of the preparations at several doses the protective effect in infections with Salmonella typhimurium and Klebsiella pneumoniae increases to different extent. At lower doses fraction 3 increases in vitro the mitogen-induced proliferation of the thymus cells.

[The immunomodulating properties of a macro glycopeptide isolated from serum. II. The activation of macrophages and polymorphonuclear cells].

The stimulating properties of three fractions of a glucomacropeptide consisting of different carbohydrate and peptide components were studied. The phagocytic activity of polymorphonuclears was increased on the 24th hour and of macrophages on the 3rd day after application of the preparations to mice. In vitro fraction 3 stimulates the lysozyme activity and the synthesis of proteins and Clq of the macrophages complement.

[Measuring neuraminidase activity by the thiobarbiturate method].

A number of reducing agents used for removing the excess of periodate in the reaction of the neuraminidase (EC 3.2.1.

[The use of a glycomacropeptide of kappa-casein as a substrate for neuraminidase].

Glycomacropeptide from milk was studied; its molecular mass and amino acid composition were evaluated. When the glycomacropeptide was used as a substrate of neuraminidase, it exhibited many advantages as compared with ovomucin (high molecular substrate of the enzyme) due to increased content of sialic acids in the glycomacropeptide composition and to high solubility.