X-ray Crystallography of Concanavalin-A and IF7
- Zaphron Richardson
- Kathleen Dwyer
- Norma Duke (Argonne National Laboratory, SBC-CAT)
The development of vascular (blood) supply is an essential step in the growth and metastasis of malignant tumors. Annexin 1, involved in human anti-inflammatory processes, is of use as a potential anticancer therepeutic; it is capable of highly specific tumor vasculature recognition. Recent articles have identified the carbohydrate ligand-mimicking 7-mer peptide, IFLLWQR (IF7) as capable of targeting annexin A1 in mouse tumors. IF7 can exhibit “unprecedented tumor targeting activity”, and has been detected in mouse tumors within a few minutes of intravenous injection of the peptide. Thus, IF7 may have the potential to act as a delivery vehicle of anticancer drugs to the location of the tumor. Concanavalin-A is a carbohydrate binding protein, originally extracted from Jack Bean Canavalia ensiformis. It binds to various sugars, glycoproteins and glycolipids, by recognition of a α-D-mannosyl or a α-D-glucosyl group. We have grown crystals of Concanavalin-A, cross-linked them with glutaraldehyde, then soaked them in a solution of IF7, in an attempt to identify the peptide’s biologically active conformation.