Patent ID: 9493523
Filing Date: 2016-11-15
CPC Classification: C07K,C12N,C12Y

Claim Text:
1. A method of producing an artificial antibody against a predetermined antigen, comprising: (i) preparing a RNF8-FHA domain library comprising randomized-loop polypeptides obtained by randomizing two or more of the following loops (a′) to (d′) in the E3 ubiquitin ligase RNF8-FHA domain comprising the amino acid sequence of SEQ ID NO:1: (a′) a loop consisting of the 41 (b′) a loop consisting of the 49 (c′) a loop consisting of the 78 (d′) a loop consisting of the 108 wherein each of the randomized-loop polypeptides comprises the amino acid sequence shown by SEQ ID NO:1 except that a random sequence is introduced into two or more loops selected from the group consisting of (a′) to (d′), and no amino acid residues are deleted from, substituted for, inserted into, or added to any regions of the amino acid sequence other than loops (a′), (b′), (c′), and (d′), and (ii) selecting a randomized-loop polypeptide that binds to the antigen as the artificial antibody from among the randomized-loop polypeptides of the RNF8-FHA domain polypeptide library, wherein unmodified RNF8-FHA domain has substantially no binding affinity for the antigen.