Patent ID: 6399763
Filing Date: 2002-06-04
Classification: C07K,C12N,C40B

Abstract:
An expression library comprising a repertoire of nucleic acid sequences, which sequences are not cloned from a source immunised with a target antigen, each nucleic acid sequence encoding a fragment of a variable domain of a heavy chain of an immunoglobulin devoid of light chains wherein said heavy chain forms the complete antigen binding site (VHH), said fragment comprising at least the three complementarity determining regions (CDRs) and the parts of the framework region that link them, wherein the extent of sequence variability in said library is enhanced compared to the corresponding naive expression library repertoire by the introduction of mutations in one or more of the CDRs of said nucleic acid sequences or by shuffling the CDR and framework regions present in the library to generate new combinations of CDR and framework regions.