ABSTRACT
The antigenic determinants of Trichosanthin (TCS) were studied using cyanogen bromide cleavage of TCS and immunoblotting technique. 21 McAbs prepared against TCS could be divided into 5 groups according to the patterns of their reactivities with CNBr-fragments of TCS (CBTf1-4). (1) 7 antibodies bind to CBTf 1;(2) 2 antibodies bind to CBTf2;(3)2 antibodies bind to CBTf 4;(4)7 antibodies are cross-reactive with these fragments; (5) 3 antidodies bind to none of 4 fragments. Using two fragments CBTf1 and CBTf2 as competitors in a ELISA competition test, quantitative determination of antigenicity of TCS fragments by 4 McAbs to native TCS has shown that the maximal amount of bound antibody for CBTf1 with 2 McAbs reached 50% and for CBTf2 with another McAb nearly 50%. From these data, we concluded that TCS fragments have kept antigenic determinants as native TCS and it is very essential for us to study the structure-function relationship of TCS.