Methods for producing members of specific binding pairs

Abstract

A member of a specific binding pair (sbp) is identified by expressing DNA encoding a genetically diverse population of such sbp members in recombinant host cells in which the sbp members are displayed in functional form at the surface of a secreted recombinant genetic display package (rgdp) containing DNA encoding the sbp member or a polypeptide component thereof, by virtue of the sbp member or a polypeptide component thereof being expressed as a fusion with a capsid component of the rgdp. The displayed sbps may be selected by affinity with a complementary sbp member, and the DNA recovered from selected rgdps for expression of the selected sbp members. Antibody sbp members may be thus obtained, with the different chains thereof expressed, one fused to the capsid component and the other in free form for association with the fusion partner polypeptide. A phagemid may be used as an expression vector, with said capsid fusion helping to package the phagemid DNA. Using this method libraries of DNA encoding respective chains of such multimeric sbp members may be combined, thereby obtaining a much greater genetic diversity in the sbp members than could easily be obtained by conventional methods.

1 - 6 . (canceled) 
     
     
         7 . A filamentous bacteriophage particle displaying on its surface a binding molecule which has a binding domain able to bind target epitope or antigen, wherein the binding domain of the binding molecule consists of an antibody heavy chain variable domain with the structure of FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4, the particle contains nucleic acid with a nucleotide sequence encoding the binding molecule, and the particle is in a population of filamentous bacteriophage particles displaying a population of said binding molecules having a range of binding specificities. 
     
     
         8 . A population of filamentous bacteriophage particles, the particles displaying on their surface a binding molecule which has a binding domain able to bind target epitope or antigen, wherein the binding domain of the binding molecule consists of an antibody heavy chain variable domain with the structure of FR1-CDR1-FR2-CDR2-FR3-CDR3-FR4, the particles contain nucleic acid with a nucleotide sequence encoding the binding molecule, and the population of particles display a population of said binding molecules having a range of binding specificities. 
     
     
         9 - 17 . (canceled) 
     
     
         18 . A filamentous bacteriophage particle according to  claim 7  wherein the binding molecule is synthetic. 
     
     
         19 . A filamentous bacteriophage particle according to  claim 18  wherein the nucleotide sequence encoding the binding molecule is provided by combining unrearranged V segments with D and J segments. 
     
     
         20 . A filamentous bacteriophage particle according to  claim 7  wherein the nucleotide sequence encoding the binding molecule is derived by in vitro mutagenesis of an existing antibody coding sequence or pre-existing phage antibodies. 
     
     
         21 . A filamentous bacteriophage particle according to  claim 7  wherein the nucleotide sequence encoding the binding molecule is derived from a peripheral blood lymphocyte. 
     
     
         22 . A filamentous bacteriophage particle according to  claim 7  wherein said nucleic acid is comprised in a phagemid genome within the filamentous bacteriophage particle. 
     
     
         23 . A population of filamentous bacteriophage particles according to  claim 8  wherein the binding molecules are synthetic. 
     
     
         24 . A population of filamentous bacteriophage particles according to  claim 23  wherein the nucleotide sequences encoding the binding molecules are provided by combining unrearranged V segments with D and J segments. 
     
     
         25 . A population of filamentous bacteriophage particles according to  claim 8  wherein the nucleotide sequences encoding the binding molecules are derived by in vitro mutagenesis of existing antibody coding sequences or pre-existing phage antibodies. 
     
     
         26 . A population of filamentous bacteriophage particles according to  claim 8  wherein the nucleotide sequences encoding the binding molecules are derived from peripheral blood lymphocytes. 
     
     
         27 . A population of filamentous bacteriophage particles according to  claim 8  wherein said nucleic acid is comprised in a phagemid genome within the filamentous bacteriophage particles.