A representative scheme of AT photoreaction in light-adapted bacteriorhodopsin (LA-BR) and in the presence and absence of K. It also shows the photoreaction of K and isolation of pure K photochemistry. Exp..1 represents the AT-BRs photochemistry. Exp..2 uses two excitation pulses, a few ps after the actinic excitation of AT-BR a mixture of AT-BR and K intermediate was produced. TA measurement after 60 ps of the actinic excitation records the photochemistry of the AT-BR and K. Subtracting the correct weighted contribution of AT-BRs data from Exp..2 gives the photochemistry of K. Source data are provided as a Source Data file.
