. Author manuscript; available in PMC: 2023 Mar 9.

Published in final edited form as: J Am Chem Soc. 2022 Feb 24;144(9):3968–3978. doi: 10.1021/jacs.1c12305

Table 2.

Predicted and Observed Driving Forces, Absorption Peak Maxima, and FQYs for Each Dronpa2 Hybrid^a

			observed driving force Δ $\bar{ν}$		observed absorption peak maximum (transition energy ${\bar{ν}}_{abs}$ )

hybrid protein	predicted combined driving force Δ $\bar{ν}$ (cm⁻¹)	predicted absorption peak maximum (nm)	(cm⁻¹)	(kcal/mol)	(cm⁻¹)	(nm)	(kcal/mol)	FQY (%)	FQY SD (%)
T159E/2,3-F₂ (enhancing)	10490	459.6	9990	28.6	21520	464.7	61.5	9.2	0.1
T159E	N/A	N/A	9190	26.3	21160	472.5	60.5	31	2
T159E/3-OCH₃ (compensating)	7260	490.3	6870	19.6	20260	493.6	57.9	38.9	0.4
Dronpa2 (“wild type”)	N/A	N/A	7070	20.2	20310	492.4	58.1	46	2
S142A/2,3-F₂ (compensating)	6590	495.9	6160	17.6	20030	499.3	57.3	42	2
S142A	N/A	N/A	5290	15.1	19780	505.5	56.6	29.8	0.4
S142A/3-CH₃ (enhancing)	4480	510.7	4170	11.9	19510	512.6	55.8	28.5	0.3

The observed driving force is calculated from eq 1 with an electronic coupling V₀ of 9530 cm⁻¹.²³ SD: standard deviation. The predicted absorption peak maxima are at most 5 nm from the observed ones, with better accuracy for redder species.