The effect of temperature on the interaction of Yersinia pseudotuberculosis lipopolysaccharide with chitosan.

The mechanism of binding of lipopolysaccharide (LPS) from Yersinia pseudotuberculosis to low-molecular-weight chitosan was investigated using sedimentation analysis, centrifugation in glycerol and percoll density gradients, and isopicnic centrifugation in cesium chloride. The LPS interaction with chitosan was shown to be a multistage process that depended on time and reaction temperature. A stable LPS-chitosan complex could be formed only after preliminary incubation of the initial components at an elevated temperature (37 degrees C). This temperature caused the LPS dissociation and promoted its binding to chitosan. The LPS binding to chitosan results in further dissociation of the endotoxin and formation of the complex with a molecular weight that is tens of times less than the initial molecular weight of LPS. The obtained complex remained stable in solutions of high ionic strength.

Peptidoglycan from Yersinia pseudotuberculosis: isolation and general characterization.

A peptidoglycan layer of Y. pseudotuberculosis cell wall was isolated from cells after treatment with sodium dodecylsulphate and digestion with pronase. The isolated peptidoglycan contained glucosamine, muramic acid, alanine, glutamic acid and diaminopimelic acid in the approximate molar ratio of 1:0.8:2:1:1.