c-Met kinase binding proteins
Polypeptides comprising monomer domains that bind to c-Met, or portions thereof, are provided.
1 . A polypeptide comprising a monomer domain that binds to c-Met, wherein the monomer domain:
is a non-naturally-occurring monomer domain consisting of 30 to 50 amino acids;
comprises at least one disulfide bond; and
binds to an ion.
2 . The polypeptide of claim, wherein binding of at least one monomer domain to c-Met inhibits dimerization of Met.
3 . The polypeptide of claim 1 , wherein at least one monomer domain binds to the Sema domain of c-Met, thereby preventing binding of Met ligands to c-Met.
4 . The polypeptide of claim 1 , wherein the polypeptide comprises at least one and no more than six monomer domains.
5 . The polypeptide of claim 1 , wherein the polypeptide comprises at least two monomer domains and the monomer domains are linked by a linker.
6 . The polypeptide of claim 5 , wherein the linker is a peptide linker.
7 . The polypeptide of claim 6 , wherein the linker is between 4 to 12 amino acids long.
8 . The polypeptide of claim 1 , wherein the monomer domains are each between 35 to 45 amino acids.
9 . The polypeptide of claim 1 , wherein the polypeptide comprises at least one monomer domain with binding specificity for a blood factor, thereby increasing the serum half-life of the polypeptide compared to a polypeptide lacking the blood factor monomer domain.
10 . The polypeptide of claim 9 , wherein the blood factor is serum albumin, an immunoglobulin or an erythrocyte.
11 . The polypeptide of claim 1 , wherein each monomer domain comprises two disulfide bonds.
12 . The polypeptide of claim 1 , wherein each monomer domain comprises three disulfide bonds.
13 . The polypeptide of claim 1 , wherein the ion is a metal ion.
14 . The polypeptide of claim 1 , wherein the ion is a calcium ion.
15 . The polypeptide of claim 1 , wherein at least one of the monomer domains is derived from a LDL-receptor class A domain.
16 . The polypeptide of claim 1 , wherein at least one of the monomer domains is derived from an EGF-like domain.
17 . The polypeptide of claim 1 , wherein the monomer comprises an amino acid sequence in which:
at least 10% of the amino acids in the sequence are cysteine; and/or
at least 25% of the amino acids are non-naturally-occurring amino acids.
18 . A method for identifying a polypeptide that binds to c-Met, the method comprising,
screening a library of polypeptides for affinity to c-Met; and
selecting a polypeptide comprising at least one monomer domain that binds to c-Met, wherein the monomer domain:
is a non-naturally-occurring monomer domain;
comprises at least one disulfide bond; and
binds to an ion.
19 . The method of claim 18 , wherein the selecting step comprises selecting a polypeptide that reduces HGF-mediated cell proliferation and/or migration.
20 . The method of claim 18 , further comprising selecting a polypeptide that inhibits tumor growth in an animal.
21 . The method of claim 18 , wherein the monomer comprises an amino acid sequence in which:
at least 10% of the amino acids in the sequence are cysteine; and/or
at least 25% of the amino acids are non-naturally-occurring amino acids.
22 . The method of claim 18 , further comprising linking the monomer domain in the selected polypeptide to a second monomer domain to form a library of multimers, each multimer comprising at least two monomer domains;
screening the library of multimers for the ability to bind to c-Met; and
selecting a multimer that binds c-Met.
23 . The method of claim 18 , further comprising linking the monomer domain in the selected polypeptide to a second monomer domain to form a library of multimers, each multimer comprising at least two monomer domains;
screening the library of multimers for the ability to bind to a target molecule other than the c-Met; and
selecting a multimer that binds to the target molecule.
24 . The method of claim 18 , further comprising a step of mutating at least one monomer domain, thereby providing a library comprising mutated monomer domains.
25 . The method of claim 18 , wherein the library of monomer domains is expressed as a phage display, ribosome display or cell surface display.
26 . The method of claim 18 , wherein the polypeptide comprises at least two monomer domains and the monomer domains are linked by a linker.
27 . The method of claim 26 , wherein the linker is a peptide linker.
28 . The method of claim 27 , wherein the linker is between 4 to 12 amino acids long.
29 . The method of claim 18 , wherein the monomer domains are each between 35 to 45 amino acids.
30 . The method of claim 18 , wherein each monomer domain comprises two disulfide bonds.
31 . The method of claim 18 , wherein each monomer domain comprises three disulfide bonds.
32 . The method of claim 18 , wherein the ion is a metal ion.
33 . The method of claim 18 , wherein the ion is a calcium ion.
34 . The method of claim 18 , wherein at least one of the monomer domains is derived from a LDL-receptor class A domain.
35 . The method of claim 18 , wherein at least one of the monomer domains is derived from an EGF-like domain.
36 . The method of claim 18 , wherein the monomer domain comprises an amino acid sequence in which:
at least 10% of the amino acids in the sequence are cysteine; and/or
at least 25% of the amino acids are non-naturally-occurring amino acids.
37 . A polynucleotide encoding the polypeptide of claim 1.