Method of detecting auto-antibodies from patients suffering from rheumatoid arthritis, a peptide and assay kit
AssigneeStichting voor de Technische Wetenschappen
InventorsWaltherus Jacobus Wilhelmus VAN VENROOIJ, Jan Wouter DRIJFHOUT, Martinus Adrianus Maria VAN BOEKEL, Gerardus Jozef Maria PRUIJN
Life of this patent
Estimating the term…
Abstract
Peptides useful in determining the presence of autoantibodies in patients suffering from rheumatoid arthritis are disclosed.
Claims21
A method of detecting autoantibodies from patients suffering from rheumatoid arthritis, wherein at least one reactive peptide comprising a citrullin residue or analogue thereof is contacted with the forementioned autoantibodies for a time sufficiently long to allow a complex to be formed between the at least one reactive peptide and the autoantibodies, after which the complex is detected, characterised in that said autoantibodies are contacted with a peptide unit comprising the motif XG, and a peptide unit comprising the motif XnonG, wherein X is a citrullin residue or an analogue thereof, G is the amino acid glycine and nonG is an amino acid other than glycine.
A method according to one of the preceding claims, characterised in that the peptide unit with XG motif and the peptide unit with XnonG motif are part of a multipeptide.
A method according to one of the preceding claims, characterised in that the XnonG peptide unit is not derived from (pro) fillaggrin, fibrin, fibrinogen, vimentin, cytokeratin 1 and cytokeratin 9.
A method according to one of the preceding claims, characterised in that the XG peptide unit XnonG peptide unit is selected from the group comprised of:
- 0002-27
- H Q K R G Cit G W S R A A
- 0002-29
- H Q R R V Cit G W S R A A
- 0002-31
- H Q R R T Cit G G S R A A
- 0002-32
- H Q R K W Cit G A S R A A
- 0002-36
- H Q F R F Cit G Cit S R A A
- 0002-37
- H Q K W R Cit G R S Cit A A
- 0002-63
- H Q F R F Cit G W S R A A
- and the XnonG peptide is selected from the group comprised of:
- 0107-32
- K P Y T V Cit K F M R R P
- 0107-35
- A R F Q M Cit H Cit R L I R
- 0107-45
- Y S F V W Cit S H A R P R
- 0113-30
- A R F Q M R H Cit R L I R
- 0218-36
- R N L R L Cit R E R N H A
A peptide comprising a sequence with the formula (II):
- (A1-A2-A3-A4-A5)-Cit-(A6)-(A7-A8-A9-A10-A11) (II)
- wherein
- A1-A2-A3-A4-A5 is an amino acid sequence selected from:
- RHGRQ
- IRCitYK
- HGRQCit
- GRQCitCit
- FQMCitH
- CitWRGM
- ARFQM
- QCitYKW
- KPYTV
- RNLRL
- RRRCitY
- RFKSN
- RGKSN
- RWVSQ
- MKPRY
- KSFVW
- YSFVW
- FQMRH
- RNMNR
- RMGRP
- and homologous sequences thereof;
- A6 represents an amino acid other than glycine;
- A7-A8-A9-A10-A11 represents an amino acid sequence selected from:
- KYIIY
- TNRKF
- KWCitKI
- CitRAVI
- RCitGHS
- CitGRSR
- CitYIIY
- CitRLIR
- IERKR
- FMRKP
- FMRRP
- ERNHA
- AVITA
- TPNRW
- TYNRW
- RTPTR
- RIVVV
- HARPR
- RGMCitR
- IRFPV
- and homologous sequences thereof;
- as well as analogues of the peptides with the formula (II).
A peptide comprising a sequence with the formula (III):
- (B1-B2-B3-B4-B5-B6)-Cit-(B7)-(B8-B9-B10-B11) (III)
- wherein
- B1-B2-B3-B4-B5-B6 is an amino acid sequence selected from:
- INCitRAS
- ICitKRLY
- KCitCitYNI
- RLYFICit
- IRQGAR
- CitERCitVQ
- CitHQRIT
- RICitRVCit
- GRNQRY
- RCitRQHP
- CitCitRCitVA
- RPKQHV
- RKCitGCitR
- RCitCitRNT
- RCitQCitFT
- QLVYLQ
- QYNRFK
- CitLRHIR
- PRCitCitCitK
- RCitQVRY
- GRCitHAH
- ARHVIR
- RCitGHMF
- GRNIRV
- QIFYLCit
- RQGPIA
- GVYLVR
- NCitCitRRV
- KCitRLCitY
- GRRCitCitL
- RMPHCitH
- and a homologous sequence thereof;
- B7 represents an amino acid other than glycine;
- B8-B9-B10-B11 represents an amino acid sequence selected from:
- CitHRR
- CitIRR
- FRRN
- AQTT
- GYPK
- RPPQ
- GCitRK
- PIPR
- YTIH
- RIKA
- CitRVR
- TRRP
- TIRP
- IKCitR
- RNVV
- CitRRY
- CitRPR
- TRCitCit
- CitCitGR
- LCitRCit
- RVRCit
- VPRT
- YCitFR
- ARCitCit
- RQCitR
- HIRR
- CitMMR
- CitRICit
- VRKS
- PCitCitR
- CitRRK
- and homologous sequences thereof;
- as well as functional analogues of the peptides with the formula (III).
A peptide comprising a sequence with the formula (IV)
- (C1-C2)-(C3-C4-C5)-X-G-C6-(C7-C8-C9-C10) (IV)
- wherein
- C1-C2 is HQ, GF, EG or GV;
- C3-C4-C5 represents 3 amino acids of which at least 1, and preferably 2 independently of each other are basic, aromatic or V;
- C6 is equal to a basic or aromatic amino acid, or equal to A, G, E, P, V, S or Cit or analog thereof;
- and
- C7-C8-C9-C10 is SRAA, SCitAA, RPLD, RVVE or PGLD;
- as well as analogues of the peptide with the formula (IV).
A multi-peptide, characterised in that it is a linear or branched multipeptide, comprising at least two linear or cyclic peptide sequences selected independently of each other from
- a peptide unit selected from peptide units with the formula (II) and (III) and analogues thereof;
- a peptide unit with the formula (IV) and analogues thereof.
A method for the selection of a peptide suitable for the diagnosis of RA, wherein a peptide library is screened with antibodies obtained from patients with RA and wherein the peptide library is selected from a group comprised of:
- Lib (1):
- H Q E X X Cit X X S R A A
- Wherein X=any amino acid except cysteine and tryptophan;
- Lib (2):
- H Q X X X Cit G X S R/Cit A A
- Wherein X=any amino acid except cysteine but including Citrulline;
- Lib (3):
- H Q E X X Cit X X S R/Cit A A
- Wherein X=any amino acid except cysteine but including Citrulline;
- Lib (4):
- X X X X X X Cit X X X X X
- Wherein X=any amino acid except cysteine but including Citrulline or equivalents thereof.
Dependencies are inferred from the claim text.