. Author manuscript; available in PMC: 2018 Oct 18.

Published in final edited form as: J Am Chem Soc. 2017 Oct 5;139(41):14638–14648. doi: 10.1021/jacs.7b07849

Table 1.

Time constants from TRIR Data for PixD and n-FY8 substituted PixD^a

	τ₁/ps	τ₂/ps	τ₃/ps	τ₄/ps	<τ>/ps^d
PixD^b	2.5±0.1	20±0.5	110±2	525±15	96
3-FY8 PixD^b	4.5±0.3	33±1	217±5	1300±100	347
2,3-F₂Y8 PixD^c	3±1	60±1	1395±45	infinite	917
3,5-F₂Y8 PixD^c	2.5±0.5	54±1	965±20	infinite	640
2,3,5-F₃Y8 PixD^c	4.5±1	48±1	1030±30	infinite	730

PixD Light State^b	3±0.2	24±0.5	563±7	infinite	23

Unless noted, the TRIR data are from the dark state of the wild-type and F-Tyr PixD variants. Data were globally analyzed using Glotaran.⁴⁵

Four time constants were needed to adequately describe the data for the dark and light states of PixD and 3-FY8 PixD.

Very long kinetics were observed for the 2,3-F₂Y8, 3,5-F₂Y8 and 2,3,5-F₃Y8 substituted proteins, and only three time constants were needed to describe the data for these proteins, followed by an ‘infinite’ lifetime extending beyond the range of the TRIR measurement.

Mean lifetime of the excited state decay calculated from the global analysis at 1380 cm⁻¹.