Figure 1
From: Chemistry of conjugation to gold nanoparticles affects G-protein activity differently
Effect of AuNP on steady state Tryptophan fluorescence from Gα i1 in inactive state. In order to monitor the effect of non-covalent interaction of AuNP and Gαi1, intrinsic tryptophan steady state fluorescence was monitored. A final concentration of 400 nM Gαi1 in 5 mM Hepes-Na (pH 8.0), 10 mM NaCl, 0.5 mM MgCl2, 1 μM GDP was used to monitor the spectrum in all the experiments. The solid line represents 0 nM AuNP; dotted line represents 0.05 nM AuNP; dashed line represents 0.1 nM AuNP; dash-dot-dash line represents 0.2 nM AuNP; dash-dot-dot line represents 0.3 nM AuNP; Short dash-short dash line represents 0.4 nM AuNP; short dash-long dash line represents 0.5 nM AuNP. Inset displays the double-logarimithic plot of the quenching of Gαi1 tryptophan fluorescence related to addition of AuNP. Spectra are representative and experiments were repeated several times. All the spectra were recorded at 25°C.