Claims for Patent: 6,107,059

Summary for Patent: 6,107,059

Title:	Peptide library and screening method
Abstract:	A random peptide library constructed by transforming host cells with a collection of recombinant vectors that encode a fusion protein comprised of a carrier protein fused to a random peptide through a proteolytic cleavage site can be used to identify ligands that bind to a receptor. The screening method results in the formation of a complex comprising the fusion protein bound to a receptor through the random peptide ligand, and the random peptide can easily be identified and analyzed by virtue of the carrier protein and associated proteolytic cleavage site.
Inventor(s):	Hart; Charles P. (Mountain View, CA)
Assignee:	Affymax Technologies N.V. (Curaco, NL)
Application Number:	07/876,288
Patent Claims:	1. A method of generating a peptide library comprising the steps of: (a) transforming host cells with a set of recombinant DNA vectors, each member of which encodes a different tripartite fusion protein consisting essentially of a carrier protein, a peptide, and a proteolytic cleavage site between said carrier protein and said peptide, such that at least 1000 and up to about 10.sup.8 different transformants are formed, wherein said different members differ from one another with respect to the peptide encoded; and (b) culturing said host cells transformed in step (a) under conditions suitable for expression of the fusion protein. 2. The method of claim 1, wherein said host cell is E. coli, said vector is a plasmid, said carrier protein is selected from the group consisting of maltose binding protein, streptavidin, His.sub.n where n is at least 3, ubiquitin, cellulose binding protein, and glutathione-S-transferase, and said proteolytic cleavage site is selected from the group consisting of a site for Factor Xa cleavage, a site for enterokinase cleavage, and a site for collagenase cleavage. 3. The method of claim 2, wherein said carrier protein is the maltose binding protein and said proteolytic cleavage site is a site for Factor Xa cleavage. 4. The method of claim 3, wherein said plasmid further encodes a signal peptide that directs secretion of the tripartite fusion protein into the periplasm of said host cell. 5. The method of claim 3, wherein said peptide is five to seventy-five amino acid residues in length. 6. The method of claim 5, wherein said peptide comprises amino acid residues that introduce conformational constraints on the peptide. 7. The method of claim 6, wherein said peptide assumes a conformation characteristic of a conformation selected from the group consisting of a zinc finger, leucine zipper, cysteine crosslinking via disulphide bridge formation, beta turn, and alpha helix. 8. The method of claim 1, wherein said peptide library is a secondary library, and said peptide of said tripartite fusion protein is a variation of a lead peptide sequence.

Details for Patent 6,107,059

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Smith & Nephew, Inc.	SANTYL	collagenase	Ointment	101995	06/04/1965		2039-02-26