Surface display of selenocysteine-containing peptides
First Claim
1. An amplifiable genetic particle, comprising:
- a surface containing a protein to which one or more recombinantly expressed peptides are covalently linked wherein each peptide has one or more selenocysteines located at a specific and unique site.
1 Assignment
0 Petitions
Accused Products
Abstract
The naturally-occurring amino acid selenocysteine (Sec) is incorporated uniquely and specifically in the context of a polypeptide displayed on the surface of an amplifiable genetic particle (phage, cell or spore) in response to incorporation signals engineered in the encoding DNA. In addition to conferring the unique activities of the selenol group to the chemistry of the displayed peptide, Sec also provides a unique handle for specific chemical modification of the displayed peptide. In addition to increasing the palette of available residues in a random peptide library to 21 possibilities, the present invention also provides a means of tethering virtually any desired chemical functionality to the incorporated Sec.
8 Citations
28 Claims
-
1. An amplifiable genetic particle, comprising:
a surface containing a protein to which one or more recombinantly expressed peptides are covalently linked wherein each peptide has one or more selenocysteines located at a specific and unique site. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
-
22. A fusion protein, comprising:
- a recombinantly expressed protein containing one or more selenocysteines at a predetermined site in the protein, wherein the recombinantly expressed protein is fused to a known ligand for a target molecule.
- View Dependent Claims (23, 24)
-
25. A method of screening for peptide-ligand fusion molecules having improved binding to a target molecule compared to non-fused ligand, comprising:
-
(a) reacting chemically derivatized selenocysteine residues in a random peptide library with a ligand to form a chemically modified peptide library, the chemically modified peptide library being displayed on the surface of an amplifiable particle;
(b) allowing the chemically modified peptide library to bind to the target molecule, wherein the target molecule is immobilized before or after binding to the peptide library;
(c) removing unbound particles;
(d) eluting bound particles; and
(e) identifying peptide-ligand fusion molecules from step (d) with improved binding to the target molecules. - View Dependent Claims (26)
-
-
27. A method of identifying required DNA sequence elements for incorporation of selenocysteine into peptides comprising the steps of:
-
(a) fusing a selenocysteine expression cassette to a surface peptide of an amplifiable genetic particle, whereby expression of the surface peptide is dependent upon incorporating a selenocysteine residue;
(b) forming a library of sequence variants of the selenocysteine expression cassette; and
(c) selecting for particles which are genetically amplifiable.
-
-
28. A method for discovery of structurally constrained ligands for a target molecule comprising the following steps:
-
(a) reacting a structurally constrained peptide library displayed on the surface of an amplifiable genetic particle, comprising one or more randomized amino acid residues flanked by a cysteine residue on one side and a selenocysteine residue on the other side, with a target molecule to form bound particles;
(b) removing unbound particles;
(c) eluting bound particles; and
(d) identifying peptide sequence displayed on the eluted bound particles.
-
Specification