Phage display evolution of a peptide substrate for yeast biotin ligase and application to two-color quantum dot labeling of cell surface proteins

A novel orthogonal biotinligase-acceptor peptide (AP) pair prepared from yeast biotin ligase (yBL) using phage display with a new 15-amino acid substrate called yeast acceptor peptide (yAP) is used for site-specific protein-labeling. The fusion proteins are coexpressed in the same cell with differently colored quantum dots.