Table 2. Contribution of Y84 and Y105 to POPC-STARD2 Binding Free Energy from FEP Calculations^a.

Mutation		Forward (kcal/mol)	Backward (kcal/mol)	BAR (kcal/mol)	ΔΔGbinding (kcal/mol)
Y84A	PC	12.38	–11.29	11.98 ± 0.12	1.81
	noPC	10.43	–9.62	10.17 ± 0.08
Y105A	PC	14.89	–12.15	13.34 ± 0.18	2.54
	noPC	9.96	–11.72	10.79 ± 0.08

^aTransformation of each tyrosine to alanine in the absence and presence of POPC from forward and backward simulations and the corresponding BAR estimate.