Φ-Values obtained were either zero or fractional, with no Φ-value of 1 (Tables 2 and 3), indicating no part of the protein is as fully formed in the transition state as it is in the native state. To interpret a Φ-value analysis, it is customary to consider Φ-value patterns, rather than to try to interpret individual Φ-values. This allows one to determine which regions of the protein are fully unfolded, partially folded or fully folded in the transition state.28 The Φ-values obtained are thus generally classified into low, medium and high classes, with the boundaries chosen to reflect the overall Φ-value distribution (e.g. see Ref. 29): in our case, the cut-offs used are: low, Φ ≤ 0.15; medium, Φ = 0.16–0.5; high, Φ ≥ 0.51.