Abstract: Methods of generating conditionally active biologic proteins, in particular therapeutic or diagnostic proteins, which are more active at an aberrant condition than at a normal physiological condition. The methods include discovery methods using libraries of proteins and assays employing physiological concentrations of components of bodily fluids. The conditionally active biologic proteins may be further evolved, conjugated to other molecules, masked, reduced in activity by attaching a cleavable moiety. Criteria for selecting starting proteins for the discovery methods, as well as formats of the proteins are also disclosed.

Abstract: The disclosure provides a method for generation of humanized full length antibodies in mammalian cells. A library of humanized variants is provided with high, validated human framework diversity without requiring back-mutations to retain original affinity. Synthetic CDR encoding fragment libraries derived from a template antibody are ligated to human framework region encoding fragments from a human framework pool limited only to germline sequences from a functionally expressed anti-bodies. The vector comprises a nucleic acid sequence encoding HC framework region 4. No CDR grafting or phage display is required.