Immunological relatedness of ribosome-inactivating proteins from the Cucurbitaceae family.

The immunological relatedness of various ribosome-inactivating proteins (RIPs) from the Cucurbitaceae family was examined using enzyme-linked immunosorbent assay (ELISA). The proteins studied included trichosanthin (TCS), beta-trichosanthin (beta-TCS), alpha-momorcharin (alpha-MMC), beta-momorcharin (beta-MMC), momorcochin (MCC), luffaculin (LFC) and Mirabilis antiviral protein (MAP). In general, an antigen exhibited the highest immunoreactivity in an assay using it own antibodies when compared with others RIPs, and MAP demonstrated the lowest immunoreactivity in most ELISAs employing antibodies raised against the other RIPs. LFC also exhibited very low immunoreactivity in most assays, TCS and beta-TCS are immunologically disparate in a number of ELISAs. alpha-MMC and beta-MMC are immunologically related but not identical. MCC manifested immunological relatedness to the momorcharins to a certain extent.