Covalent HLA-B27/peptide complex induced by specific recognition of an aziridine mimic of arginine.
The class I major histocompatibility complex (MHC) glycoprotein HLA-B27 binds short peptides containing arginine at peptide position 2 (P2). The HLA-B27/peptide complex is recognized by T cells both as part of the development of the repertoire of T cells in the cellular immune system and during activation of cytotoxic T cells. Based on the three-dimensional structure of HLA-B27, we have synthesized a ligand with an aziridine-containing side chain designed to mimic arginine and to bind covalently in the arginine-specific P2 pocket of HLA-B27. Using tryptic digestion followed by mass spectrometry and amino acid sequencing, the aziridine-containing ligand is shown to alkylate specifically cysteine 67 of HLA-B27. Neither free cysteine in solution nor an exposed cysteine on a class II MHC molecule can be alkylated, showing that specific recognition between the anchor side-chain pocket of an MHC class I protein and the designed ligand (propinquity) is necessary to induce the selective covalent reaction with the MHC class I molecule.
Weiss
G A
GA
Department of Chemistry, Harvard University, Cambridge, MA 02138, USA.
Valentekovich
R J
RJ
Collins
E J
EJ
Garboczi
D N
DN
Lane
W S
WS
Schreiber
S L
SL
Wiley
D C
DC
D000345:Affinity Labels / Q000737:chemistry; D001120:Arginine / Q000031:analogs & derivatives*; D001388:Aziridines / Q000737:chemistry*; D001665:Binding Sites; D002942:Circular Dichroism; D015796:HLA-B27 Antigen / Q000737:chemistry*; D015798:HLA-DR1 Antigen / Q000378:metabolism; D006801:Humans; D008024:Ligands; D010455:Peptides / Q000737:chemistry / Q000276:immunology*; D011485:Protein Binding; D013816:Thermodynamics
D000345:Affinity Labels; D001388:Aziridines; D015796:HLA-B27 Antigen; D015798:HLA-DR1 Antigen; D008024:Ligands; D010455:Peptides; D001120:Arginine