Isothermal fluorescence titration

Fig. 17.18 Characterization of GTP Green (a) absorption spectrum in MeOH (b)excitation and emission spectra in MeOH (c) fluorescence emission spectra (excitation = 480nm)of G49 with 100pM of GTP, ATP, all other 14 analytes and blank control in lOmM HEPES buffer (pH = 7.4) (d) fluorescence emission spectra (excitation 480nm, cutoff 495nm) of G49 with 500, 100, 50, 20, 12, lOpM GTP and blank control in lOmM HEPES buffer (pH = 7.4) (e) binding isotherm from the fluorescence titration experiment with emission at 540nm (f) picture of G49 with analytes under 365 nm UV lamp light...

Figure 7.36 Peptide association with GroEL (a) Fluorescence emission spectra from fluorescence binding titration experiment with fixed concentration of AMPH+ peptide(0.5 / M) titrated with GroEL until saturation in buffer pH 7.5 at 20°C. Note blue shift and increase in emission intensity as titration progresses. (b) Three binding isotherms from three fluorescence binding titration experiments involving the indicated peptides under conditions described in (a) (Reproduced from Preuss et al., 1999, Fig. 6).

Costa and co-workers have reported 80, a fluorescent squaramide-containing macrocyclic receptor for monitoring sulfate in water [97]. Isothermal titration calorimetry was employed to characterize the host-guest association of 80 with S04 , PhOPOs " and 204 dianions (titration carried out in methanol at 294 K). The data was fitted to a 1 1 binding model and it was foimd that 80 boimd S04 (4.6 1.0 x 10 M ) with the... 

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