Phage-displayed single-chain variable fragment library
Disclosed herein is a phage-displayed single-chain variable fragment (scFv) library, that comprised a plurality of phage-displayed scFvs characterized with (1) a specific CS combination; (2) a specific distribution of aromatic residues in each CDR; and (3) a specific sequence in each CDR. The present scFv library could be used to efficiently produce different antibodies with binding affinity to different antigens. Accordingly, the present disclosure provides a potential means to generate different antigen-specific antibodies promptly in accordance with the need in experimental researches and/or clinical applications.
1. A phage-displayed single-chain variable fragment (scFv) library comprising a plurality of phage-displayed scFvs, wherein each of the plurality of phage-displayed scFvs comprises a first heavy chain complementarity determining region (CDR-H1), a second heavy chain CDR (CDR-H2), a third heavy chain CDR (CDR-H3), a first light chain CDR (CDR-L1), a second light chain CDR (CDR-L2), and a third light chain CDR (CDR-L3),
wherein,
each of the CDR-H1, CDR-L2 and CDR-L3 has a type 1 canonical structure (CS), whereas each of the CDR-H2 and CDR-L1 has a type 2 CS; and
each of the CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3 has a distribution of aromatic residues that is similar to the distribution of aromatic residues in the corresponding CDR-H1, CDR-H2, CDR-H3, CDR-L1, CDR-L2, and CDR-L3 of a natural antibody; wherein
the CDR-L1 is encoded by a first coding sequence comprising the nucleic acid sequence of any of SEQ ID NOs: 2-10, the CDR-L2 is encoded by a second coding sequence comprising the nucleic acid sequence of any of SEQ ID NOs: 11-14, the CDR-L3 is encoded by a third coding sequence comprising the nucleic acid sequence of any of SEQ ID NOs: 15-22, the CDR-H1 is encoded by a fourth coding sequence comprising the nucleic acid sequence of any of SEQ ID NOs: 23-26, the CDR-H2 is encoded by a fifth coding sequence comprising the nucleic acid sequence of any of SEQ ID NOs: 27-28, and the CDR-H3 is encoded by a sixth coding sequence comprising the nucleic acid sequence of any of SEQ ID NOs: 29-106.
2. The phage-displayed scFv library of claim 1 , wherein the phage is a M13 phage or a T7 phage.
3. The phage-displayed scFv library of claim 1 , wherein at least one of the plurality of phage-displayed scFvs is specific for a protein antigen selected from the group consisting of human epidermal growth factor receptor 2 (HER2), maltose-binding protein (MBP), bovine serum albumin (BSA), human serum albumin (HSA), lysozyme, interleukin-1 beta (IL-1β), hemagglutinin of influenza virus (HA), nucleoprotein of influenza virus (NP), vascular endothelial growth factor (VEGF), epidermal growth factor receptor 1 (EGFR1), epidermal growth factor receptor 3 (EGFR3), glucagon receptor, human DNase I, programmed death-ligand 1 (PD-L1), sialic acid binding Ig-like lectin 3 (SIGLEC 3), fragment crystallizable region (Fc region) of immunoglobulin G (IgG), and rituximab.