Atomic Force Microscopy Study of Protein–Protein Interactions in the Cytochrome CYP11A1 (P450scc)-Containing Steroid Hydroxylase System

Abstract

Atomic force microscopy (AFM) and photon correlation spectroscopy (PCS) were used for monitoring of the procedure for cytochrome CYP11A1 monomerization in solution without phospholipids. It was shown that the incubation of 100 μM CYP11A1 with 12% Emulgen 913 in 50 mM KP, pH 7.4, for 10 min at T = 22°C leads to dissociation of hemoprotein aggregates to monomers with the monomerization degree of (82 ± 4)%. Following the monomerization procedure, CYP11A1 remained functionally active. AFM was employed to detect and visualize the isolated proteins as well as complexes formed between the components of the cytochrome CYP11A1-dependent steroid hydroxylase system. Both Ad and AdR were present in solution as monomers. The typical heights of the monomeric AdR, Ad and CYP11A1 images were measured by AFM and were found to correspond to the sizes 1.6 ± 0.2 nm, 1.0 ± 0.2 nm and 1.8 ± 0.2 nm, respectively. The binary Ad/AdR and AdR/CYP11A1mon complexes with the heights 2.2 ± 0.2 nm and 2.8 ± 0.2 nm, respectively, were registered by use of AFM. The Ad/CYP11A1mon complex formation reaction was kinetically characterized based on optical biosensor data. In addition, the ternary AdR/Ad/CYP11A1 complexes with a typical height of 4 ± 1 nm were AFM registered.

Atomic force microscopy monitoring of the temperature dependence of the cytochrome BM3 oligomeric state

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Detection of hepatitis C virus core protein in serum by atomic force microscopy combined with mass spectrometry

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SOI-nanowire biosensor for the detection of D-NFAT 1 protein

“…Для этой цели в последнее время разрабатываются новые типы биосенсоров на основе нанотехнологий, в частности, сенсор на основе АСМ [1][2][3][4], оптические нанобиосенсоры [5][6][7][8], нанопроволочные биосенсоры [9,10]. Наибольший интерес для диагностики представляют нанопроволочные биосенсоры (НП-биосенсоры) в связи с тем, что они относятся к классу так называемых безметковых ("label-free") детекторов и позволяют проводить регистрацию макромолекул в режиме реального времени.…”