Disclosure of the tuberous lectin composed of homogeneous tetramers in Pinellia pedatisecda Schott.

Pinellia pedatisecta (Schott) and Pinellia ternata (Thumb) Breit, whose tuberous stems are an important Chinese medicine, taxonomically belong to Pinellia, Araceae species. Pinellia contains various lectins in their tubers, leading to distinct roles in Chinese medicine. Difference of the lectins, however, is little known between P. pedatisecta and P. ternata tubers. For addressing to this purpose, lectins were isolated from their tuberous stems, purified through porcine thyroglobulin chromatography, analyzed with 2D-gel and Q-Trap mass spectrometry, and evaluated with hemagglutinating assays. The results showed that they possess completely different components of lectins though the lectins could specifically bind to mannose. P. ternata had the tuberous lectin composed of heterogeneous tetramer (L1)2(L2)2 with the similar molecular weight but distinct pI 5.8 and pI 6.2. Comparatively, P. pedatisecta mainly contained the tuberous lectin composed of homogeneous tetramer with the same molecular weight and pI 5.8. As a result of the lectin difference between P. pedatisecta and P. ternata, it probably leads to distinct pharmacologic variability. From this perspective, P. pedatisecta could be useful for anticancer research in some ways.