Interaction of wheat germ agglutinin with porphyrin compounds - potential anticancer agents

Abstract

Wheat germ agglutinin (WGA) is the first studied plant lectin shown to bind more strongly to tumour cells than to normal ones. WGA interacts with prostate cancer cells, human pancreatic cells and colon-cancer cells. Our results showed the interaction of WGA with two porphyrin compounds - Fe porphyrin and Pd porphyrin. The dissociation constants for the porphyrin binding was kD (0.08-1.02 μM) showing high affinity for the two porphyrins for this protein. The hyperbolic titration curve indicated the presence of a single porphyrin binding site. In conclusion, we show that two photosentisizers with anticancer activity Fe porphyrin and Pd porphyrin, have high affinity for WGA. Since WGA binds to cancer cells, the results suggest that it may have utility in the targeted delivery of drugs for cancer.