An image contrast agent selectively activated by prostate specific antigen

A family of image contrast agent conjugates designed to undergo enzymatic activation has been synthesized. The agents underwent activation both with enzymatically active prostate specific antigen (PSA) and α-chymotrypsin, releasing free fluorophore via cleavage of a three-component system. A hexapeptide derivative showed exclusive activation by PSA and constitutes a method for tracking PSA activity in vitro.

A three-component enzyme activated image contrast system was demonstrated using a family of tyrosine–chromophore conjugates linked by an inert spacer. A selective substrate for PSA was discovered, which releases free fluorophore on exposure to this key biomarker.Figure optionsDownload as PowerPoint slide