Figure 2: Scientific Reports

Figure 2

From: Red fluorescent protein-based cAMP indicator applicable to optogenetics and in vivo imaging

Figure 2

Spectroscopic characterisation of Pink Flamindo. (a) Excitation and emission spectra of purified Pink Flamindo protein in the presence (solid line) or absence (dashed line) of 100 μM cAMP. Each fluorescent intensity (FI) was normalised to the peak of FI in the absence of cAMP. (b) Absorbance spectra of 30 μM Pink Flamindo in the presence (solid line) or absence (dashed line) of 100 μM cAMP. (c) Dose-response curve of Pink Flamindo for cAMP (, red line) and cGMP (■, gray line). K d values calculated using the Hill equation were 7.2 μM for cAMP and 94 μM for cGMP. The peak of FI in the absence of cAMP or cGMP was normalised to 0, and the peak of FI in the presence of 1 mM cAMP was normalised to 1. The data represent the means ± standard deviation (n = 3). (d) Titration curves of Pink Flamindo against pH in the presence (, solid line) or absence (, dashed line) of 100 μM cAMP. The peak FI for each pH was normalised to the peak of FI in the presence of cAMP at pH 9.0. The data represent the means ± standard deviation (n = 3).