Figure 7

G6PDH and 6PGDH oxidation results in selective damage to amino acids within the protein sequence. G6PDH and 6PGDH (54 μM and 58 μM monomer, respectively) were incubated in the absence or presence of AAPH (10 or 100 mM, 37 °C, 180 min). Panels (A) and (B) map the oxidative changes detected at individual amino acids by LC–MS in G6PDH and 6PGDH, respectively, after incubation with 100 mM AAPH. The vertical axis indicates the % modification of the residues (Trp, Met, Tyr and His) present at specific sites, calculated as outlined in the Materials and methods from three different replicates, with the horizontal axis indicating the amino acid sequence and numbering. The positions of the binding sites for the substrate and NADP⁺ are indicated on the horizontal axis, in blue and orange, respectively. The residues that act as the proton acceptor (His239, H239) in G6PDH, and the proton acceptor (Lys183, K183) and proton donor (Glu190, E190) in 6PGDH, are indicated in pink.