Mutated immunoglobulin-binding polypeptides
An Fc-binding polypeptide of improved alkali stability, comprising a mutant of a parental Fc-binding domain of Staphylococcus Protein A (SpA), as defined by SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 6, SEQ ID NO: 7, SEQ ID NO: 22, SEQ ID NO: 51 or SEQ ID NO: 52, wherein at least the asparagine or serine residue at the position corresponding to position 11 in SEQ ID NO: 4-7 has been mutated to an amino acid selected from the group consisting of glutamic acid, lysine, tyrosine, threonine, phenylalanine, leucine, isoleucine, tryptophan, methionine, valine, alanine, histidine and arginine.
1. An Fc-binding polypeptide which comprises a sequence as defined by KEX 1 Q X 2 AFYEILX 3 LP NLTEEQRX 4 X 5 F IX 6 X 7 LKDX 8 PSX 9 SX 10 X 11 X 12 LAEAKX 13 X 14 NX 15 AQAPK (SEQ ID NO: 53), where individually of each other:
X 1 =A or Q or is deleted
X 2 =E,K,Y,T,F,L,W,I,M,V,A,H or R
X 3 =H or K
X 4 =A or N
X 5 =A,G,S,Y,Q,T,N,F,L,W,I,M,V,D,E,H,R or K,
X 6 =Q or E
X 7 =S or K
X 8 =E or D
X 9 =Q or V or is deleted
X 10 =K,R or A or is deleted
X 11 =A,E or N or is deleted
X 12 =I or L
X 13 =K or R
X 14 =L or Y and
X 15 =D, F,Y,W,K or R.
2. The polypeptide of claim 1 , wherein individually of each other:
X 1 =A or is deleted
X 2 =E
X 3 =H
X 4 =N
X 6 =Q
X 7 =S
X 8 =D
X 9 =V or is deleted
X 10 =K or is deleted
X 11 =A or is deleted
X 12 =I
X 13 =K and
X 14 =L.
3. The polypeptide of claim 1 , wherein: X 1 =A, X 2 =E, X 3 =H, X 4 =N, X 5 =S,Y,Q,T,N,F,L,W,I,M,V,D,E,H,R or K, X 6 =Q, X 7 =S, X 8 =D, X 9 =V, X 10 =K, X 11 =A, X 12 =I, X 13 =K, X 14 =L, and X 15 =D.
4. The polypeptide of claim 1 , wherein: X 1 is deleted, X 2 =E, X 3 =H, X 4 =N, X 5 =A, X 6 =Q, X 7 =S, X 8 =D, X 9 V, X 10 =K, X 11 =A, X 12 =I, X 13 =K, X 14 =L, and X 15 =D.
5. The polypeptide of claim 1 , wherein: X 1 =A, X 2 =E, X 3 =H, X 4 =N, X 5 =A, X 6 =Q, X 7 S, X 8 =D, X 9 is deleted, X 10 =K, X 11 =A, X 12 =I, X 13 =K, X 14 =L, and X 15 =D.
6. The polypeptide of claim 1 , wherein: X 1 =A, X 2 =E, X 3 =H, X 4 =N, X 5 =A, X 6 =Q, X 7 =S, X 8 =D, X 9 =V, X 10 is deleted, X 11 =A, X 12 =I, X 13 =K, X 14 =L, and X 15 =D.
7. The polypeptide of claim 1 , wherein: X 1 =A, X 2 =E, X 3 =H, X 4 =N, X 5 =A, X 6 =Q, X 7 =S, X 8 =D, X 9 =V, X 10 =K, X 11 is deleted, X 12 =I, X 13 =K, X 14 =L, and X 15 =D.
8. The polypeptide of claim 1 , wherein: X 1 =A, X 2 =E, X 3 =H, X 4 =N, X 5 =A, X 6 =Q, X 7 =S, X 8 =D, X 9 =V, X 10 =K, X 11 =A, X 12 =I, X 13 =K, X 14 =L, and X 15 =F,Y,W,K or R.
9. The polypeptide of claim 1 , wherein said polypeptide does not comprise any sequence defined by an amino acid sequence selected from the group consisting of SEQ ID NOs: 1-16, 17-34 and 36-52.
10. A Fc-binding polypeptide consisting of a sequence that is at least 90% identical to to KEX 1 Q X 2 AFYEILX 3 LP NLTEEQRX 4 X 5 F IX 6 X 7 LKDX 8 PSX 9 SX 10 X 11 X 12 LAEAKX 13 X 14 NX 15 AQAPK (SEQ ID NO: 53), where individually of each other:
X 1 =A or Q or is deleted
X 2 =E,K,Y,T,F,L,W,I,M,V,A,H or R
X 3 =H or K
X 4 =A or N
X 5 =A,G,S,Y,Q,T,N,F,L,W,I,M,V,D,E,H,R or K,
X 6 =Q or E
X 7 =S or K
X 8 =E or D
X 9 =Q or V or is deleted
X 10 =K,R or A or is deleted
X 11 =A,E or N or is deleted
X 12 =I or L
X 13 =K or R
X 14 =L or Y and
X 15 =D, F,Y,W,K or R.
11. A multimer comprising a plurality of polypeptides as defined by claim 1 .
12. The multimer of claim 11 , wherein the polypeptides are linked by linkers comprising up to 15 amino acids.
13. The multimer of claim 11 , which is a dimer, trimer, tetramer, pentamer, hexamer, heptamer, octamer or nonamer.
14. A multimer comprising a plurality of polypeptides as defined by a sequence selected from the group of sequences defined by SEQ ID NO: 17, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20, SEQ ID NO: 30, SEQ ID NO: 31, SEQ ID NO: 32, SEQ ID NO: 33, SEQ ID NO: 34 and SEQ ID NO: 35.
15. The multimer of claim 11 , further comprising at, or within 1-5 amino acid residues from, the C-terminal or N-terminal one or more coupling element, selected from the group consisting of one or more cysteine residues, a plurality of lysine residues and a plurality of histidine residues.
16. A separation matrix, wherein a plurality of multimers of claim 11 have been coupled to a solid support.
17. The separation matrix of claim 16 , wherein the multimers have been coupled to the solid support via thioether bonds.
18. The separation matrix of claim 16 , wherein the solid support is a polysaccharide.
19. The separation matrix of claim 16 , wherein the IgG capacity of the matrix after 24 hours incubation in 0.5 M NaOH at 22+/−2° C. is at least 80% of the IgG capacity before the incubation.
20. The separation matrix of claim 16 , wherein the IgG capacity of the matrix after 24 hours incubation in 1.0 M NaOH at 22+/−2° C. is at least 70% of the IgG capacity before the incubation.
21. A method of isolating an immunoglobulin, comprising isolating an immunoglobulin with the separation matrix of claim 16 .
22. The method of claim 21 , comprising the steps of:
a) contacting a liquid sample comprising an immunoglobulin with the separation matrix,
b) washing said separation matrix with a washing liquid,
c) eluting the immunoglobulin from the separation matrix with an elution liquid, and
d) cleaning the separation matrix with a cleaning liquid.
23. The method of claim 22 , wherein the cleaning liquid is alkaline at a pH of 13-14.
24. The method of claim 22 , wherein the cleaning liquid comprises 0.1-1.0 M NaOH or KOH.
25. The method of claim 22 , wherein steps a)-d) are repeated at least 10 times.
26. The method of claim 22 , wherein steps a)-c) are repeated at least 50 times.
27. A multimer comprising a plurality of polypeptides as defined by claim 10 .
28. The multimer of claim 10 , wherein the polypeptides are linked by linkers comprising up to 15 amino acids.
29. The multimer of claim 10 , with is a dimer, trimer, tetramer, pentamer, hexamer, heptamer, octamer or nonamer.