Table IX.

Contribution of Hydrogen Bonds to Protein Stability

Mutation	ΔGHB (kcal mol−1)a
Ser → Alab	−0.9 ± 0.9
Thr → Valb	−1.0 ± 0.5
Tyr → Pheb	−1.2 ± 0.6
Asn → Alac	−1.1 ± 0.6
Peptide → Esterd	−1.1 ± 1.6

^aΔG_HB = Δ(ΔG) (hydrogen bonded) − Δ(ΔG) (not hydrogen bonded). See Figure 1 in Ref.46.

^bFrom TableTable VIII.

^cFrom Ref.32.

^dFrom Ref.52 and a personal communication from Evan Powers and Jeff Kelly.