US Patent 8648176 Engineered proteins with high affinity for DOTA chelates

The present invention features, inter alia, compositions and methods for the treatment of cancer and infectious disease. The compositions include engineered proteins that specifically bind a metal chelate and may be bispecific. For example, the engineered proteins may bind (a) a target (e.g., a cellular protein) on a cancerous cell or a pathogen and (b) a metal chelate comprising DOTA, or an active variant thereof, and a metal ion such as a radionuclide. By virtue of the multiple binding sites, the engineered protein effectively delivers a metal chelate to a cell one wishes to destroy.