C04232: Extracellular PSMA Fusion Protein, Recombinant Baculovirus, and Plasmid Vectors
Technical Details:
The invention provides the means to purify large quantities of a fusion protein containing the entire extracellular segment of the human Prostate Specific Membrane Antigen (also known as PSMA, glutamate carboxypeptidase II, folate hydrolase, and NAALADase). PSMA is a well characterized surface antigen expressed at high levels in prostate cancer and is the ligand of FDA approved prostate cancer imaging agents. Additionally, PSMA is a marker of tumor neovasculature, a glutamate carboxypeptide in the brain, and an intestinal glutamate folate hydrolase. Insect cells infected with the recombinant baculovirus secrete the fusion protein within 40 hours after infection, with peak protein production at 70 hours. The fusion protein has two amino-terminal tags for quantification and purification. One or both purification tags can be removed by thrombin or enterokinase digestion, respectively. The fusion protein demonstrates glutamate carboxypeptidase enzymatic activity.
Looking for Partners:
The fusion protein is an ideal target for developing therapeutic or diagnostic agents against PSMA. The design of the protein ensures that selected agents will only interact with the extracellular segment of PSMA, avoiding transmembrane and cytoplasmic epitopes. This protein has already been successfully used to produce nanomolar affinity ligands that recognize native PSMA1. Additionally, the protein is a pure source for studying PSMA biology, such as enzymatic activity, enzyme inhibition, structure, and protein-protein interactions.
Publication: Cancer Res. 2012 Aug 1;72(15):3887.
