Study of characteristics of electrostatic interaction between RNases and mica surface using atomic force microscopy

Surface-Dependent Differences in the Adsorption of Pancreatic and Microbial Ribonucleases Visualized by Atomic Force Microscopy

“…We have shown that binase much more effectively than pancreatic RNAse adsorbs on negatively charged substrate. The process of adsorption of RNAses depends on the distribution of charge on the surface of protein globule and is accompanied by aggregation of protein molecules [5]. The results presented in this work confirm our previous observations.…”

“…This is most likely due to the higher polarity of RNAse A compared to binase. The dipole moments of RNAse A and binase are 545 D and 225 D, respectively 5 . The presence of high dipole moment, characterizing the skewness of a distribution of negative and positive charges in a protein molecule, determines the most probable spatial orientation of the dissolved protein molecules that are close to uncharged substrate surface.…”

“…We selected the following optimal concentrations of enzyme: no more than 50 µg/ml for mica 5 , and no more than 10 µg/ml for pyrolytic graphite. The interaction of RNAses with mica and pyrolytic graphite did not exceed 5 min.…”

“…Using AFM, it is possible to successfully analyze the dynamics of adsorption and conformation of various substances, including protein molecules on atomically smooth surfaces [1][2][3][4][5][6] . The study of the physical adsorption of proteins on different surfaces helps to reveal the peculiarities of their functioning in contact with the cell membrane and other biological substrates and contributes to the understanding of the role of interphase phenomena in biological processes 2,4,5 .…”

“…Using AFM, it is possible to successfully analyze the dynamics of adsorption and conformation of various substances, including protein molecules on atomically smooth surfaces [1][2][3][4][5][6] . The study of the physical adsorption of proteins on different surfaces helps to reveal the peculiarities of their functioning in contact with the cell membrane and other biological substrates and contributes to the understanding of the role of interphase phenomena in biological processes 2,4,5 . Along with the study of adsorption, methods of atomic force microscopy are widely used to study the local structure of the cell membrane and artificial bilayer structures, as they allow one to obtain a valuable information about conformational changes in lipid membranes when interacting with different biomolecules to detect subtle structural features of the lipid layers and to estimate their morphometric parameters [6][7][8][9] .…”