Purification of Preventive Antigen of Gram-Negative Bacteria

摘要

The following working hypothesis was tested: the specific anti-infectious activity of classical lipopolysaccharide-protein complex of gram-negative bacteria may be more potent than that of lipopolysaccharide. The experiment determined how to obtain protective antigen in a soluble state as mild as possible. The EDTA extraction procedure of the cell wall was applied as a starting material of antigen. The EDTA extract was potent as a highly protective antigen and separated into two fractions electrophoretically; a slow moving fraction and a fast moving one. The slow moving fraction was potent. The content of protein and total sugar was 32.8% of 27.8% respectively. The protective potency of the slow moving fraction was slightly elevated compared to EDTA extract or cell wall preparations. On the other hand, the fast moving fraction did not show any protection under the experimental conditions. The protective potency of lipopolysaccharide fraction was remarkably elevated compared with that of the slow moving fraction. It seems that lipopolysaccharide fraction may play a main role in the experimental protection against the challenge of Ps. aeruginosa. (Author)