Fig. 8.

Digestion of synthetic precursors of inhibitor-resistant A*68:01 and B*27:05 ligands by purified 20S proteasome. A, Cleavage of a 31-mer substrate, including the overlapping sequences of an A68 and a B27 ligand (boxed) in the absence or in the presence of the indicated inhibitors. Thin, medium and thick arrows indicate peptide bonds whose cleavage result in a joint yield of digestion products of 0.1 to 1%, 1.1 to 10% and >10%, respectively (see supplemental Table S6). B, Cleavage of a 30-mer substrate, containing the sequence of an inhibitor sensitive A68 ligand. The arrows follow the same convention as in panel A (see supplemental Table S7).