AFM image (a) and the corresponding density of distribution with height ρ(h)) for CYP11A1/AdR/Ad (b); comparison of ρ(h)AdR/Ad/CYP11A1 distribution vs. normalized ρ(h)CYP11A1/Ad, ρ(h)CYP11A1/AdR and ρ(h)AdR/Ad distributions (the summarized area under curves ρ(h) for binary mixtures is reduced to 100%) (c); differential curve (Δρ) between ρ(h)CYP11A1/AdR/Ad for ternary mixture and the sum of ρ(h)CYP11A1/Ad, ρ(h)CYP11A1/AdR and ρ(h)AdR/Ad for binary mixtures (d). Arrows (1) indicate the images of protein monomers. Arrows (2) indicate the images of the binary protein complexes. Arrows (3) indicate the images of the ternary CYP11A1/AdR/Ad complexes. Tapping mode. Experimental conditions were as follows: mixture of 7.5 μM solutions (10 μl each) of appropriate individual proteins (monomeric CYP11A1, containing 1.5% Emulgen 913, Ad and AdR) in 50 mM KP, pH 7.4, was incubated for 10 min, diluted 2.5 times in the same buffer, and a 5-μl portion of the mixture was immediately placed onto mica.
Ivanov et al. Nanoscale Res Lett 2011 6:54 doi:10.1007/s11671-010-9809-5