X-ray crystal structure of an anti-Buckminsterfullerene antibody Fab fragment: Biomolecular recognition of C-60

We have prepared a monoclonal Buckminsterfullerene specific antibody and re port the sequences of its light and heavy chains. We also show, by x-ray cr ystallographic analysis of the Fab fragment and by model building, that the fullerene binding site is formed by the interface of the antibody light an d heavy chains. Shape-complementary clustering of hydrophobic amino acids, several of which participate in putative stacking interactions with fullere ne, form the binding site. Moreover, an induced fit mechanism appears to pa rticipate in the fullerene binding process. Affinity of the antibody-fuller ene complex is 22 nM as measured by competitive binding. These findings sho uld be applicable not only to the use of antibodies to assay and direct pot ential fullerene-based drug design but could also lead to new methodologies for the production of fullerene derivatives and nanotubes as well.