A PD-L1 nano-antibody and a PD-L2 nano-antibody, and a bispecific antibody having both the PD-L1 nano-antibody and the PD-L2 nano-antibody are disclosed. The bispecific antibody can block PD-1/PD-L1 and PD-1/PD-L2 pathways at the same time. The bispecific antibody can reactivate T cells, enhance immune responses, and more effectively improve the inhibitory effect on tumor occurrence and development.

The invention provides singleplex and multiplex assays for screening of antigen-binding molecules for their affinity to antigens by normalizing for the concentration of the antigen-binding molecule.

The present invention relates to a method for preparing a novel antibody library and a library prepared thereby. The antibody library prepared according to the present invention contains antibodies having excellent physical properties against a plurality of antigens, thereby having functional diversity and containing a plurality of unique sequences, and thus can be favorably used as an antibody library.

Provided herein are compositions comprising recombinant polyclonal proteins (RPPs) derived from mammalian plasma cells and plasmablasts. Also provided are methods of using the RPPs.

Described herein is a protein display selection method which uncouples a protein of interest (POI) library from the display selection system. Display of the POI can be achieved by forming a covalent bond between the POI and the anchor protein post expression either by enzymatic protein ligation (e.g. SpyLigase, SnoopLigase, sortase, butelase, peptiligase etc.) or by spontaneous covalent bond formation (e.g. SpyTag/SpyCatcher, SnoopTag/SnoopCatcher, etc.).

The POI library is fused to a tethering sequence, for example SpyTag, at the C-terminus of the POI which then forms a covalent bond to a capture sequence found on an anchor protein, for example, the SpyCatcher-fused anchor protein, e.g., a SpyCatcher-geneIII protein (SpyCatcher-pIII) fusion, for the most common form of phage display. Nucleic acid constructs, host cell systems and methods of producing the protein display systems are also provided.

Methods for display of recombinant proteins or protein libraries on the surface of lower eukaryotes such as yeast and filamentous fungi are described. The methods are useful for screening libraries of recombinant proteins in lower eukaryotes to identify particular proteins with desired properties from the array of proteins in the libraries. The methods are particularly useful for constructing and screening antibody libraries in lower eukaryotes.

Provided are methods for the identification of mutant kinases that are resistant to inhibition by a kinase inhibitor. In some embodiments, the methods may be used to assess a test compound or kinase inhibitor for the risk of the development of resistance in vivo, e.g., during clinical administration to treat a disease such as a cancer.

The present application provides a method of synthesizing a genetically-encoded chemical modification of a peptide library. A vector in a substrate, such as a phage, is modified to include a peptide linker and a modification to form a genetic “barcode”. The barcode is screened against potential targets which may be used in drug discovery.

Provided herein are methods for identifying pairs of protein binding partners, mutations of which may inform the discovery of pharmaceutically useful small molecules. The methods disclosed herein may allow for the adaptation of the native protein degradation system to modulate specific disease targets at the protein level, in particular, for targets that have long been considered undruggable.

The present invention provides human anti-human epidermal growth factor receptor (EGFR) antibodies and their encoding genes and applications thereof. By gene engineering means and phage surface display technology, the present invention screens anti-human EGFR gene engineering single chain antibody from fully synthetic single chain human antibody library, and obtains the antibody variable gene sequence thereof, and based thereon, constructs intact human monoclonal antibody, to further obtain high-purity antibody protein. The binding affinity of the antibody of the present invention with human EGFR is no more than 1 nM, and the mutants affinity thereof is no more than 10 nM; and the identification of the immunity activity and bioactivity of antibodies protein IgG is completed, confirming that the antibody of the present invention has good bioactivity of inhibiting the tumor growth of EGFR expressing cell A431 tumor-bearing model mouse. The antibodies of the present invention provides specific antibody drugs for preventing and treating EGFR targeted tumor and other diseases such as inflammation and autoimmune diseases.