Preparation and preliminary application of monoclonal antibodies against Trichokirin-S1, a small ribosome-inactivating peptide from the seeds of Trichosanthes kirilowii.

Trichokirin-S1, a small ribosome-inactivating peptide recently purified from the seeds of Trichosanthes kirilowii, has potential clinical applications because of its small molecular mass. Two stable strains of hybridomas (1F11 and 2A5) that can secrete highly specific monoclonal antibodies (mAbs) against Trichokirin-S1 have been developed using the hybridoma technique. The isotypes of these two mAbs, 1F11 and 2A5, were determined to be IgG2a and IgG1, respectively. The affinity constants, which were measured by non-competitive ELISA, were found to be 2.3 x10(8) M(-1) and 2.8 x 10(8) M(-1), respectively. An immunoaffinity method using 2A5-coupled Sepharose 4B was successfully developed to purify Trichokirin-S1. These two antibodies have also been used to detect Trichokirin-S1 in Western blot.