STREPTAVIDIN MUTANTS HAVING SECONDARY FUNCTIONAL DOMAINS

摘要

Streptavidin molecules are disclosed that contain a secondary functionaldomain. In preferred embodiments, the secondary domainis a cell adhesion peptide incorporated in the streptavidin amino acidsequence at a site not interfering with biotin binding. In a preferredembodiment, the cell adhesion peptide is arginine-glycine-aspartate (Arg-Gly-Asp)(RGD). The peptide is preferably placed on an exposedloop of the streptavidin molecule, such as within the loop defined by residues63 to 69. The mutant streptavidin molecule can have othercharacteristics such as reduced biotin binding due to a modification of anamino acid at the biotin binding site. Preferred uses for thedisclosed streptavidin molecules are as adaptors to bring, via astreptavidin/biotin interaction, the secondary functional domain intoproximitywith a cell or molecule to be effected and as a coating for substrates such asvascular devices or prostheses.