Comparison of dose response rates for cyt c, myoglobin, lysozyme. (a) Global dose response rates for air and low oxygen sample preparations. For reference, the calculated absorbed radiation dose by the buffer was 162 Gy for a 10 ms X-ray exposure. (b-d) Bar plots of the ratio of dose response rates for air versus low oxygen samples for most abundant modifications. (e) These ratios are plotted by color on crystal structures of cyt c (PDB 1hrc), lysozyme (PDB 1vds) and myoglobin (PDB 1ymb). No side-chain modifications were detected in the regions colored in green.