Methods for manufacturing activatable binding polypeptides comprising matrix metalloprotease cleavable moieties
Activatable binding polypeptides (ABPs), which contain a target binding moiety (TBM), a masking moiety (MM), and a cleavable moiety (CM) are provided. Activatable antibody compositions, which contain a TBM containing an antigen binding domain (ABD), a MM and a CM are provided. Furthermore, ABPs which contain a first TBM, a second TBM and a CM are provided. The ABPs exhibit an “activatable” conformation such that at least one of the TBMs is less accessible to target when uncleaved than after cleavage of the CM in the presence of a cleaving agent capable of cleaving the CM. Further provided are libraries of candidate ABPs, methods of screening to identify such ABPs, and methods of use. Further provided are ABPs having TBMs that bind VEGF, CTLA-4, or VCAM, ABPs having a first TBM that binds VEGF and a second TBM that binds FGF, as well as compositions and methods of use.
1. A method for manufacturing an activatable binding polypeptide (ABP), wherein the ABP comprises a target binding moiety (TBM), a masking moiety (MM), and a cleavable moiety (CM), and wherein the TBM specifically binds to a target protein, wherein the target protein is VEGF-A, the method comprising:
a) selecting a MM from a plurality of candidate polypeptides, wherein the selected MM inhibits binding of the TBM to its target protein, and wherein the selected MM does not have an amino acid sequence of a naturally occurring binding partner of the TBM; and
b) constructing the ABP comprising the following structure MM-CM-TBM or TBM-CM-MM, comprising synthesizing a polypeptide construct that includes the ABP,
wherein the V L of the TBM comprises the complementarity determining regions (CDRs) of the V L domain of SEQ ID NO: 30 and the V H of the TBM comprises the complementarity determining regions (CDRs) of the V H domain of SEQ ID NO: 30,
wherein the MM is positioned in the ABP such that it is capable of binding the TBM and is capable of inhibiting binding of the TBM to the target protein when the ABP is in an uncleaved state, and
wherein the CM is a substrate for a protease, wherein the CM is a matrix metalloprotease (MMP) substrate, wherein the MMP substrate is a matrix metalloprotease 1 (MMP-1) substrate, a matrix metalloprotease 2 (MMP-2) substrate, a matrix metalloprotease 9 (MMP-9) substrate, or a matrix metalloprotease 14 (MMP-14) substrate, and wherein said CM is positioned in the ABP such that in a cleaved state in the presence of the target protein, the TBM binds the target protein, and in an uncleaved state in the presence of the target protein, binding of the TBM to the target protein is inhibited by the MM.
2. The method of claim 1 , wherein the TBM comprises an antibody or antigen binding fragment thereof comprising an antigen binding domain (ABD) that binds the target protein.
3. The method of claim 2 , wherein the antigen binding fragment thereof is selected from the group consisting of a Fab fragment, a F(ab′) 2 fragment, a scFv, or a single chain antibody (scAb).
4. The method of claim 1 , wherein the CM is a substrate for a protease that is co-localized in a tissue with the target protein.
5. The method of claim 1 , wherein when the ABP is an uncleaved state the CM is positioned N-terminal to the TBM.
6. The method of claim 1 , wherein when the ABP is an uncleaved state the CM is positioned C-terminal to the TBM.
7. The method of claim 2 , wherein when the ABP is an uncleaved state the CM is positioned N-terminal to a variable light (V L ) chain of the ABD.
8. The method of claim 2 , wherein when the ABP is an uncleaved state the CM is positioned N-terminal to a variable heavy (V H ) chain of the ABD.
9. The method of claim 2 , wherein the ABD is positioned at the N-terminus of the ABP.
10. The method of claim 2 , wherein the ABD is positioned at the C-terminus of the ABP.
11. The method of claim 2 , wherein the ABD is linked to the CM.
12. The method of claim 11 , wherein the ABD is linked to the CM via a linker peptide.
13. The method of claim 1 , wherein the MM binds the TBM with less affinity and/or avidity than the TBM binds to its target protein.
14. The method of claim 1 , wherein the MM is a polypeptide of no more than 40 amino acids in length.
15. The method of claim 1 , wherein when the ABP is in an uncleaved state the ABP exhibits reduced binding to the target protein relative to when the ABP is in a cleaved state.
16. The method of claim 1 , wherein when the ABP is in a cleaved state the MM does not interfere or compete with the TBM for binding to the target protein.
17. The method of claim 1 , wherein when the ABP is in an uncleaved state the MM is linked to the CM.
18. The method of claim 16 , wherein when the ABP is in an uncleaved state the MM is linked to the CM via a linker peptide.
19. The method of claim 1 , wherein the ABP comprises a first linker peptide (L 1 ) and a second linker peptide (L 2 ), and wherein the ABP has the structural arrangement in the uncleaved state from N-terminus to C-terminus as follows: MM-L 1 -CM-L 2 -TBM or TBM-L 2 -CM-L 1 -MM.
20. The method of claim 19 , wherein the two linker peptides are not the same.
21. The method of claim 19 , wherein each of L 1 and L 2 is a peptide of about 1 to 20 amino acids in length.
22. The method of claim 19 , wherein one or both of L 1 and L 2 comprise a glycine-serine copolymer.
23. The method of claim 19 , wherein at least one of L 1 and L 2 comprises an amino acid sequence selected from the group consisting of (GS) n , (GGS) n , GSGGS (SEQ ID NO: 1) and (GGGS) n (SEQ ID NO: 2), where n is an integer of at least one.
24. The method of claim 19 , wherein at least one of L 1 and L 2 comprises an amino acid sequence selected from the group consisting of GGSG (SEQ ID NO: 3), GGSGG (SEQ ID NO: 4), GSGSG (SEQ ID NO: 5), GSGGG (SEQ ID NO: 6), GGGSG (SEQ ID NO: 7), and GSSSG (SEQ ID NO: 8).
25. The method of claim 2 , wherein the ABD is from an antibody selected from the group consisting of bevacizumab and ranibizumab.
26. The method of claim 1 , wherein the V L of the TBM comprises the V L domain of SEQ ID NO: 30 and the V H of the TBM comprises the V H domain of SEQ ID NO: 30.
27. The method of claim 1 , wherein the step of synthesizing a polypeptide construct comprises:
synthesizing a nucleic acid construct that encodes the ABP; and
expressing the ABP in a host cell that includes the nucleic acid construct.