Table 5.

Δ(ΔG) values for 151 hydrogen bonding variants from 15 proteins for Tyr → Phe, Thr → Val, and Ser → Ala variants.

	Hydrogen-bonded		Not hydrogen-bonded
Variant	number	Δ(ΔG)d (kcal mol−1)	number	Δ(ΔG)d (kcal mol−1)
Tyr → Phe a	35	−1.4 ± 0.9 (−3.6 to 1.2)	17	−0.2 ± 0.4 (−1.2 to 0.5)
Thr → Val b	25	−1.0 ± 1.0 (−3.5 to 1.9)	15	0.0 ± 0.5 (−1.7 to 1.0)
Ser → Ala c	44	−0.8 ± 0.9 (−3.8 to 1.3)	15	0.1 ± 0.4 (−0.8 to 0.5)

^aFifty-two Tyr → Phe variants from [37].

^bForty Thr → Val variants from [89].

^cFifty-nine Ser → Ala variants from [104].

^dThe negative values indicate a decrease in stability.