Figure 3.

Activation energy analysis of amide exchange for residues from P. furiosus rubredoxin. (A) The exchange rate data for Leu-51 at 28°C (▴). The corresponding data at 3°C (●) and 53°C (■) have been scaled to 28°C assuming a 17-kcal/mol activation energy. Optimal alignment of the data from the three temperatures is obtained with an apparent activation energy of 13.5 kcal/mol. (B) The far more typical case of Glu-47 in which a 17-kcal/mol activation energy factor adequately scales the data from the three different temperatures as in A.