The ribosome-inactivating proteins of Jatropha curcas curcin and curcin C have antitumor activity, but the activity level of the latter is significantly higher than the former. In order to explore the structural basis for this difference, the online homology modeling prediction software SWISSMODEL was used to predict the three dimensional structural models of the ribosomal inactivating proteins curcin and curcin C. SYBYL was used to optimize the energy of the prediction model, and PROCHECK, VERIFY 3D and ERRAT software were used to evaluate the quality of the model before and after the optimization, and then AutoDock software was used to analyze the predicted model and adenine for molecular docking. The results show that the two proteins interacted with adenine in a similar way to Ricin A, but there were differences in the types and number of amino acid residues that interact, as well as the hydrogen bonds and hydrophobic interactions formed. Among them, curcin C had the strongest binding ability with adenine, and curcin had the lowest.
