Two proteins with ribosome-inactivating, cytotoxic and abortifacient activities from seeds of Luffa cylindrica roem (Cucurbitaceae)

Two immunologically distinct glycoproteins, with a molecular weight of 28,000 and 28,5000 respectively, were isolated from seeds of Luffa cylindrica using a procedure that involved acetone precipitation, gel filtration on Sephadex G-75 and ion exchange chromatography on CM-Sepharose CL-6B. The proteins differed in the content of aspartic acid, threonine, proline and alanine but were otherwise similar in amino acid composition. The proteins were capable of inducing mid-term abortion in mice, inhibiting protein synthesis in a cell-free system and suppressing thymidine uptake by human choriocarcinoma cells.