Abstract: The effects of four kinds of anti-tumor compounds, taxol, carboplatin, ZYZ (the extractive from gleditsia), F43 (the extractive from squamocin), on the assembly and melting denaturation of tubulin in vitro were studied by turbidity and differential scanning calorimetry. The experimental results show that taxol and ZYZ enhance the assembly of tubulin, while carboplatin and F43 have no effect on the assembly of tubulin when the concentrations of all four kinds of compounds are 15 μmol•L－1.At the same time, taxol and ZYZ can make the melting points of tubuin rise, while the melting points of tubuin don't change in the presence of carboplatin and F43.The different interaction mechanisms of the compounds and tubulin have been discussed according to the above experimental results.

Key words: Tubulin, Taxol, Carboplatin, ZYZ, F43, Turbidity, DSC(differential scanning calorimetry)