| 摘要 |
NEW MATERIAL:A physiologically active peptide having an inhibiting action on increase of toxoplasma, consisting of the amino acid sequence expressed by formula I-IV. EXAMPLE:Glycyl-penta-glutaminate. USE:A preventive and remedy for toxoplasma infections disease and an immunity activating drug. PREPARATION:For instance, a normal Holstein cow is intravenously inoculated with toxoplasma RH stock trophozoit mesosoma, 5 weeks later the same toxoplasma RH stock is administered, further 2 weeks later, toxoplasma lysate antigen (TLA) is intravenously administered and then 24hr later, blood of the cow is collected to give blood serum. Next, the blood serum is hydrolyzed with protease and purified by gel-filtration and ion-exchange chromatography to give ovioactin. Amino acid sequences of the ovioactin are analyzed and therefrom the amino acid sequence of the minimum structure at active site is estimated and a substance of the minimum structures synthesized by a well- known method to afford the compound expressed by the formula I-IV. |
