Figure 3.

Digestion of synthetic precursors of HLA-B*51 ligands by recombinant ERAP1 variants. A, six synthetic peptides consisting of N-terminally extended precursors of natural HLA-B*51 ligands with Pro-2 were digested with recombinant Hap2 (red), Hap8 (blue), or Hap10 (green) ERAP1 variants. The percentage yield of each ligand is represented as a function of the digestion time. The amino acid sequence of each synthetic substrate is indicated. Dots separate the two N-terminal extensions, as present in the parental proteins, from the sequence of the natural ligand. B, the same experiments, in identical conditions as in A, were performed with six precursors of HLA-B*51 ligands with Ala-2. Error bars, S.E.