(I know this is very late, i.e. a long time after publication. Apologies!) I note that the barriers listed in Hediger 2012, Figure 12 (https://doi.org/10.1371/journal.pone.0049849.g012) are different from those listed here. Hediger 2012: "Energy differences from PM6 SPE calculations of M(C15, G0.5) optimized geometries (in kcal/mol): A. G39A: 6.9. B. T103G: 8.7. C. W104F: 8.3. For comparison (see Fig. 7) WT: 6.0."

Here (10.7717/peerj.145/table-1): WT: 7.5, G39A: 11.2, T103G: 13.6, W104F: 12.0. What are the reasons for that? Has the model/procedure changed?