Plant-Derived Lectins as Potential Cancer Therapeutics and Diagnostic Tools

Figure 2

Crystal structures of three representative lectins showing their interactions with the corresponding sugars via carbohydrate-binding domains (CBDs). (a) Mistletoe lectin I (Ricin family) with A chain (blue) and B chain (red) shown as a ribbon in a complex with galactose (protein data bank [PDB]: 1OQL). (b) The tetrameric phytohemagglutinin-L (legume family) with monomers in various colors, in complex with GlcNAc (PBD: 1FAT). (c) Polygonatum cyrtonema (GNA-related family) as a monomeric protein in complex with monomannoside (PDB: 3A0D). Dotted lines are hydrogen bonds. The structures were generated with the UCSF Chimera software (Resource for Biocomputing, Visualization, and Informatics (RBVI), USA). Binding of lectins to their respective sugars used the PDB.

(a) Mistletoe lectin I (ML-I)

(b) Phytohemagglutinin-L lectin (PHA-L)

(c) Polygonatum cyrtonema lectin (PCL)