Juthamas ChuethongKohei OdaHiroaki SakuraiIkuo SaikiWichet LeelamanitMahidol UniversityKyoto Institute of TechnologyUniversity of Toyama2018-08-242018-08-242007-03-01Biological and Pharmaceutical Bulletin. Vol.30, No.3 (2007), 428-43213475215091861582-s2.0-33847634392https://repository.li.mahidol.ac.th/handle/20.500.14594/25111Cochinin B, a novel ribosome-inactivating protein (RIP) with a molecular weight of 28 kDa, was purified from the seeds of Momordica cochinchinensis (Cucurbitaceae). The isolation procedure entailed ammonium sulfate precipitation, cation-exchange chromatography on SP Sepharose column and size-exclusion chromatography on Superdex 75 column with a fast protein liquid chromatography (FPLC) system. The first twenty N-terminal amino acid residues of Cochinin B showed homology to type I RIPs from other Momordica species. The purified Cochinin B displayed a strong inhibitory activity on protein synthesis in the cell-free rabbit reticulocyte lysate system with IC50of 0.36 nM. Furthermore, it exhibited N-glycosidase activity and cytotoxicity against Vero cell line with IC50higher than 1540 nM. Interestingly, Cochinin B manifested strong anti-tumor activities on human cervical epithelial carcinoma (HeLa), human embryonic kidney (HEK293) and human small cell lung cancer (NCI-H187) cell lines with IC50of 16.9, 114 and 574 nM, respectively. © 2007 Pharmaceutical Society of Japan.Mahidol UniversityPharmacology, Toxicology and PharmaceuticsArticleSCOPUS10.1248/bpb.30.428