Figure 5
From: Chemistry of conjugation to gold nanoparticles affects G-protein activity differently
FRET based time course measurement to study effect of AuNP conjugation on Gα i1 intrinsic GTPase activity by monitoring GTP hydrolysis. (A) Illustrates effect of non-covalently conjugated AuNP-Gαi1 on intrinsic GTPase activity. The thin solid line represents 0 nM AuNP; dotted line represents 0.1 nM AuNP; thick dark line represents 0.2 nM AuNP; dashed line represents 0.3 nM AuNP; line with grey bars represents 0.4 nM AuNP. (B) Display effect of N-terminal covalent conjugation on intrinsic GTPase activity. The solid line represents only Gαi1; dashed line represents covalently conjugated AuNP-Gαi1. In all the experiments, a final concentration of 200 nM Gαi1 was taken in a quartz cuvette containing 5 mM Hepes-Na (pH 8.0), 10 mM NaCl, 0.5 mM MgCl2, and 1 μM GDP. Non-covalent conjugation retarded the mGTP hydolysis rate. The mGTP hydrolysis rates were reduced upto 0.8 fold. N-terminal covalent conjugation drastically increases the mGTP hydrolysis rate by 12.16 fold.