Thioester-terminated water soluble polymers and method of modifying the N-terminus of a polypeptide therewith
AssigneeShearwater Corporation
InventorsMichael J. Roberts, Zhihao Fang
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Abstract
The invention provides reagents and methods for conjugating a polymer specifically to the α-amine of a polypeptide. The invention provides monofunctional, bifunctional, and multifunctional PEGs and related polymers having a terminal thioester moiety capable of specifically conjugating to the α-amine of a polypeptide having a cysteine or histidine residue at the N-terminus. The invention provides reactive thioester-terminated PEG polymers that have suitable reactivity with an N-terminal cysteine or histidine residue of a polypeptide to produce an amide bond between the PEG molecule and the polypeptide.
Claims28
A thioester-terminated reactive polymer, comprising a water soluble and non-peptidic polymer backbone having at least one terminus bonded to the structure:
- 22
- wherein:
- L is the point of bonding to the polymer backbone;
- Z is a linker;
- m is from 0 to about 12;
- Y is a heteroatom;
- each X is independently selected from H and alkyl;
- a is 0 or 1;
- and
- Q is a sulfur-containing leaving group.
A polymer conjugate of a polypeptide having a cysteine or histidine residue at the N-terminus, said polymer conjugate comprising a water soluble and non-peptidic polymer backbone having at least one terminus bonded to the structure:
- 25
- wherein:
- L is the point of bonding to the polymer backbone;
- Z is a linker;
- Y is a heteroatom;
- m is from 0 to about 12;
- each X is independently selected from H and alkyl;
- a is 0 or 1;
- W is —CH2SH or
- 26
- and
- POLYPEPTIDE is the polypeptide molecule.
A method of conjugating a polymer derivative to a polypeptide having a cysteine or histidine residue at the N-terminus, said method comprising:
- providing a polypeptide having a cysteine or histidine residue at the N-terminus;
- providing a thioester-terminated polymer, the polymer comprising a water soluble and non-peptidic polymer backbone having at least one terminus bonded to the structure:
- 27
- wherein:
- L is the point of bonding to the polymer backbone;
- Z is a linker;
- m is from 0 to about 12;
- Y is a heteroatom;
- each X is independently selected from H and alkyl;
- a is 0 or 1;
- and
- Q is a sulfur-containing leaving group;
- reacting the thioester-terminated polymer with the polypeptide to form a conjugate having the structure:
- 28
- wherein
- POLYPEPTIDE is the polypeptide molecule, and
- W is —CH2SH or
- 29
A polymer conjugate of a polypeptide having a cysteine molecule at the N-terminus, said polymer conjugate comprising two water soluble and non-peptidic polymer backbones attached at the N-terminus, the conjugate having the structure:
- 30
- wherein:
- L is the point of bonding to each of said two polymer backbones,
- L′ and Z are linkers,
- Y is a heteroatom;
- m is from 0 to about 12;
- each X is independently selected from H and alkyl;
- a is 0 or 1;
- and
- POLYPEPTIDE is the polypeptide molecule.
Dependencies are inferred from the claim text.