Method of identifying, characterising and/or designing agent or a target binding site of an agent

A method for identifying a target binding site of an agent or fragment thereof and/or designing a target binding site to which binding of an agent or fragment thereof is increased or decreased, the method comprising:

• (i) providing an agent or fragment thereof to be tested;
• (ii) providing a library of displayed polypeptides, wherein the library comprises a plurality of polypeptide molecules having different sequences derived from the target of the agent or fragment thereof;
• (iii) screening the library for polypeptide molecules to which the agent or fragment thereof binds, and identifying a first population of polypeptide molecules to which the agent or fragment thereof binds and/or a second population of polypeptide molecules to which the agent or fragment thereof does not bind;
• (iv) determining the sequences of the first and/or second population of polypeptide molecules;
• (v) identifying a target binding site of the agent or fragment thereof and/or designing a target binding site to which binding of the agent or fragment thereof is increased or decreased, from the information obtained in step (iv);
• wherein polypeptides that are not properly displayed are excluded from the step of identifying and/or designing an epitope and/or a target binding site in step (v).

A method for identifying an agent or fragment thereof and/or designing an agent or fragment thereof, to which binding of a target antigen or fragment thereof, is increased or decreased, the method comprising:

• (i) providing a target antigen or fragment thereof to be tested;
• (ii) providing a library of displayed agents, wherein the library comprises a plurality of agent molecules or fragments thereof having different sequences derived from the agent or fragment thereof;
• iii) screening the library for agent molecules to which the antigen or fragment thereof binds, and identifying a first population of agent molecules to which the antigen or fragment thereof binds and/or a second population of agent molecules to which the antigen or fragment thereof does not bind;
• (iv) determining the sequences of the first and/or second population of agent molecules;
• (v) identifying and/or designing an agent or fragment thereof to which binding of the antigen or fragment thereof is increased or decreased, from the information obtained in step (iv);
• wherein agent molecules that are not properly displayed are excluded from the step of identifying and/or designing an agent or fragment thereof in step (v).