Functional heavy chain antibodies, fragments thereof, library thereof and methods of production thereof

Abstract

The present invention relates to functional heavy chain antibodies, functional single domain heavy chain antibodies, functional VH domains, or functional fragments thereof comprising an amino acid which is neither a charged amino acid nor a C at position 45, and comprising an amino acid at position 103 independently chosen from the group consisting of R, G, K, S, Q, L, and P, and optionally an amino acid at position 108 independently chosen from the group consisting of Q, L and R, said positions determined according to the Kabat numbering.

1 . A ligand comprising a single variable domain, wherein the single variable domain specifically binds to an antigen, and the variable domain comprises a Kd for the antigen of 2 to 50 nM. 
     
     
         2 . The ligand of  claim 1 , wherein the variable domain comprises a Kd for the antigen of 0.8-3.9 nM. 
     
     
         3 . The ligand of  claim 1 , wherein the antigen is selected from the group consisting of human, protein, animal protein, cytokine, prostate specific antigen, carcinoembryonic antigen, ovalbumin, variant surface glycoprotein trypanosome, β-lactamase, TEM1, carbonic anhydrase, cutinase, potyvirus, lysozyme, linoic acid, Poly A Binding Protein Type 2, humanised mouse mAb to CD40,  Salmonella typhimurium , rotavirus, tumor necrosis factor alpha and human serum albumin. 
     
     
         4 . A dual specific ligand comprising a first single variable domain and a second a single variable domain where at least one of the first single variable domain and the second single variable domain comprises a Kd for the antigen of 2 to 50 nM. 
     
     
         5 . The ligand of  claim 4 , wherein the variable domain comprises a Kd for the antigen of 0.8-3.9 nM. 
     
     
         6 . The dual specific ligand of  claim 4 , wherein said first single variable domain specifically binds to an antigen selected from the group consisting of, human, protein, animal protein, cytokine, prostate specific antigen, carcinoembryonic antigen, ovalbumin, variant surface glycoprotein trypanosome, β-lactamase, TEM1, carbonic anhydrase, cutinase, potyvirus, lysozyme, linoic acid, Poly A Binding Protein Type 2, humanised mouse mAb to CD40,  Salmonella typhimurium , rotavirus, tumor necrosis factor alpha and human serum albumin; and wherein said second single variable domain specifically binds to an antigen selected from the group consisting of human, protein, animal protein, cytokine, prostate specific antigen, carcinoembryonic antigen, ovalbumin, variant surface glycoprotein trypanosome, β-lactamase, TEM1, carbonic anhydrase, cutinase, potyvirus, lysozyme, linoic acid, Poly A Binding Protein Type 2, humanised mouse mAb to CD40,  Salmonella typhimurium , rotavirus, tumor necrosis factor alpha and human serum albumin. 
     
     
         7 . A dual specific ligand comprising a first single variable domain and a second single variable domain, wherein the first single variable domain specifically binds to an antigen and the second single variable domain specifically binds to an antigen, wherein at least one of the first single variable domain and the second single variable domain comprises a Kd for the antigen of 2 to 50 nM. 
     
     
         8 . The dual specific ligand of  claim 7 , wherein at least one of the first single variable domain and the second single variable domain comprises a Kd for the antigen of 0.8-3.9 nM. 
     
     
         9 . The dual specific ligand of  claim 7 , wherein said first single variable domain specifically binds to an antigen selected from the group consisting of human protein, animal protein, cytokine, prostate specific antigen, carcinoembryonic antigen, ovalbumin, variant surface glycoprotein trypanosome, β-lactamase, TEM1, carbonic anhydrase, cutinase, potyvirus, lysozyme, linoic acid, Poly A Binding Protein Type 2, humanised mouse mAb to CD40,  Salmonella typhimurium , rotavirus, tumor necrosis factor alpha and human serum albumin; and wherein said second single variable domain specifically binds to an antigen selected from the group consisting of human protein, animal protein, cytokine, prostate specific antigen, carcinoembryonic antigen, ovalbumin, variant surface glycoprotein trypanosome, β-lactamase, TEM1, carbonic anhydrase, cutinase, potyvirus, lysozyme, linoic acid, Poly A Binding Protein Type 2, humanised mouse mAb to CD40,  Salmonella typhimurium , rotavirus, tumor necrosis factor alpha and human serum albumin.