| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
The major diabetes autoantigen, glutamic acid decarboxylase (GAD65), contains a region of sequence similarity, including six identical residues PEVKEK, to the P2C protein of coxsackie B virus, suggesting that cross-reactivity between coxsackie B virus and GAD65 can initiate autoimmune diabetes. We used the human islet cell mAbs MICA3 and MICA4 to identify the Ab epitopes of GAD65 by screening phage-displayed random peptide libraries. The identified peptide sequences could be mapped to a homology model of the pyridoxal phosphate (PLP) binding domain of GAD65. For MICA3, a surface loop containing the sequence PEVKEK and two adjacent exposed helixes were identified in the PLP binding domain as well as a region of the C terminus of GAD65 that has previously been identified as critical for MICA3 binding. To confirm that the loop containing the PEVKEK sequence contributes to the MICA3 epitope, this loop was deleted by mutagenesis. This reduced binding of MICA3 by 70%. Peptide sequences selected using MICA4 were rich in basic or hydroxyl-containing amino acids, and the surface of the GAD65 PLP-binding domain surrounding Lys358, which is known to be critical for MICA4 binding, was likewise rich in these amino acids. Also, the two phage most reactive with MICA4 encoded the motif VALxG, and the reverse of this sequence, LAV, was located in this same region. Thus, we have defined the MICA3 and MICA4 epitopes on GAD65 using the combination of phage display, molecular modeling, and mutagenesis and have provided compelling evidence for the involvement of the PEVKEK loop in the MICA3 epitope.
This article has been cited by other articles:
|
|
 |
|
  G. Yao, W. Chen, H. Luo, Q. Jiang, Z. Xia, L. Zang, J. Zuo, X. Wei, Z. Chen, X. Shen, et al. Identification of core functional region of murine IL-4 using peptide phage display and molecular modeling Int. Immunol., January 1, 2006; 18(1): 19 - 29. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. A. Dromey, S. M. Weenink, G. H. Peters, J. Endl, P. J. Tighe, I. Todd, and M. R. Christie Mapping of Epitopes for Autoantibodies to the Type 1 Diabetes Autoantigen IA-2 by Peptide Phage Display and Molecular Modeling: Overlap of Antibody and T Cell Determinants J. Immunol., April 1, 2004; 172(7): 4084 - 4090. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Vanhoorelbeke, H. Depraetere, R. A. P. Romijn, E. G. Huizinga, M. De Maeyer, and H. Deckmyn A Consensus Tetrapeptide Selected by Phage Display Adopts the Conformation of a Dominant Discontinuous Epitope of a Monoclonal Anti-VWF Antibody That Inhibits the von Willebrand Factor-Collagen Interaction J. Biol. Chem., September 26, 2003; 278(39): 37815 - 37821. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Bresson, M. Cerutti, G. Devauchelle, M. Pugniere, F. Roquet, C. Bes, C. Bossard, T. Chardes, and S. Peraldi-Roux Localization of the Discontinuous Immunodominant Region Recognized by Human Anti-thyroperoxidase Autoantibodies in Autoimmune Thyroid Diseases J. Biol. Chem., March 7, 2003; 278(11): 9560 - 9569. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Bearzatto, H. Naserke, S. Piquer, K. Koczwara, V. Lampasona, A. Williams, M. R. Christie, P. J. Bingley, A.-G. Ziegler, and E. Bonifacio Two Distinctly HLA-Associated Contiguous Linear Epitopes Uniquely Expressed Within the Islet Antigen 2 Molecule Are Major Autoantibody Epitopes of the Diabetes-Specific Tyrosine Phosphatase-Like Protein Autoantigens J. Immunol., April 15, 2002; 168(8): 4202 - 4208. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
