ABSTRACT
Induced by 42 degrees C, the recombinant engineering bacterial pBV/cpa408 was highly expressed. After having been pelleted by 80% (NH4)2 SO4 and dialysised, the expressed protein was isolated and purified by the gel filtration choromatography. Then according to an amount of 1.0 mg/kg, the Kunming Mice (body weighted 18g) were immuned with the purified protein by intraperitoneal inoculation. One week after the first enhanced immunization, the Kunming Mice were attacked with an amount of 1.0MLD alpha-toxin, in which the eight mice immuned all survive and the control group all died. During the period of immunization, the titre of the mouse's serum antibody was measured by ELISA. One week after the first immunization, the titre of the mice's serum antibody was 1:800, but that of one week after the first enhanced immunization reached to 1:6400.
Subject(s)
Animals , Female , Male , Mice , Antibodies, Bacterial , Blood , Antigens, Bacterial , Allergy and Immunology , Bacterial Toxins , Allergy and Immunology , Calcium-Binding Proteins , Allergy and Immunology , Immunization , Recombinant Proteins , Allergy and Immunology , Type C Phospholipases , Allergy and ImmunologyABSTRACT
The specific ScFv gene against botulinum neurotoxin A (BoNTa)was cloned into pPIC9k. Positive integrators were screened by increasing the dose of G418 in culture and expressed in Pichia pastoris GS115. As a result, engineered recombinant clone were obtained. 26 kD product of interest was seen easily in SDS-PAGE. Expression of human ScFv got the highest level 15% of total secreted proteins during 72～84 h after 1% methanol inducing. Purification of ScFv was finished by two steps: gel filter and ion exchange. Competing ELISA showed that recombinant ScFv could compete with antiserum to specific bind BoNTa.