| 摘要 |
PURPOSE:To obtain the new protein derived from human plasma, having a specific amino acid sequence, presenting such opsonin activity as to be subject to oligophagous activity by oligophagous cells like neutrophiles through its sticking to pathogenic microbes, thus useful as a preventive/therapeutic agent for infectious diseases. CONSTITUTION:Calcium chloride is added to citric acid-added human plasma to effect coagulation followed by filtration and centrifugal separation to separate serum. Polyethylene glycol is then added to the serum and the resultant precipitate is centrifuged and then dissolved in a buffer solution. The resultant solution is passed through an yeast-immobilized mannan column which is then washed and treated with a mannose- contg. buffer solution, and the adsorbed substance is eluted using a 0.15 M N- acetylglucosamine-contg. buffer solution, and the impurities in the resultant elute is removed to purify the adsorbed substance, thus obtaining the objective new protein containing an amino acid sequence of formula I and having the following characteristics: molecular weight determined by SDS-polyacrylamide gel electrophoresis under reduction: about 35kDa; having amino acid sequence of formula II at the N- terminal; and, presenting opsonin activity. This protein is useful as, e.g. a preventive/ therapeutic agent for infectious diseases. |
