Solution phase biopanning method using engineered decoy proteins
AssigneeCentocor, Inc.
InventorsKaryn O'neil, Raymond Sweet, George Heavner
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Abstract
The invention relates to a method of directing selection of biological therapeutic molecules to specific functional domains of the target biologic molecule. Selection is directed by the use of closely related molecules, where one is a decoy and the other contains the targeted domain or epitope. The invention is based on the use of physical data, which may be combined with derived data, to ascertain that the decoy and the target differ only in the specific functional domain or epitope where the binding will be directed.
Claims12
A method for selecting a blocking polypeptide ligand binding partner from a library wherein the specific functional domain of the ligand to be bound is predetermined, said method comprising the steps of:
- a) determining the functional domain of the protein to be blocked;
- b) analyzing the common structural features between the ligand and one or more species or functional homologs of that ligand;
- c) creating a decoy incorporating said common structural features of the ligand and the chosen homologs but having different structural features in the functional domain to be blocked;
- d) providing a library of putative blocking polypeptide binding partners;
- e) using said decoy in excess of the ligand binding partner for selecting binding partners that preferentially bind to the functional region of the ligand to be blocked.
A method for identifying a polypeptide which binds to a preselected epitope of a target protein, which comprises:
- a) providing a library of phage particles that express polypeptides on the surface of the phage particles;
- b) preparing a decoy protein which has changes in the amino acid sequences corresponding to the preselected epitope of the target protein;
- c) incubating the library of phage particles with the target protein to select phage particles with polypeptides that bind to the target protein;
- d) adding the decoy protein as a competitor in molar excess concentration to negatively select for phage particles specific for the preselected epitope;
- e) separating the phage particles that bind to the target protein from those that bind to the decoy protein and
- f) recovering the phage particles bound to the target protein.
Dependencies are inferred from the claim text.