Influence of acidic exopolysaccharide of Xanthomonas campestris IBPM 124 on the kinetic parameters of extracellular bacteriolytic enzymes

Interactions of a negatively charged exopolysaccharide of Xanthomonas campe stris IBPM 124 with its extracellular enzymes (muramidase, endopeptidase, a nd neutral phosphatase) and also with egg lysozyme, lysostaphin, muramidase of Streptomyces globisporus, and a bacteriolytic enzyme complex of Strepto myces albus were studied. All these enzymes were positively charged under t he conditions of their maximal activity. It was shown that interaction of t he acidic exopolysaccharide from X. campestris with these enzymes changed t heir kinetic parameters. The change was either positive (increase in reacti on rate) or negative (decrease in reaction rate) and depended on the enzyme and type of substrate cleaved. Due to such interactions, the acidic exopol ysaccharide secreted by X. campestris into the environment not only retaine d and transported positively charged exoenzymes into the near-cellular spac e, but also regulated their activity.