А. V. Dmitriev, V.A. Tverdislov
Fundamental peculiarity of nature is “chirality purity” of amino acids, carbohydrates, nuclides and many other biological active substances, made all organisms. All nuclei acids include exceptionally D-isomers (dezoxy)ribosa, and proteins synthesized in ribosome include L-isomers of amino acids. Earlier, in some series of calculating experiments we discovered, that substitution of all L-amino acids ion channels to D-amino acids with conservation of natural amino acid sequence, brings to disorder of basic functional channels characteristics. Ratio of coefficient penetrability for different ions, ion current and conductivity are plunged into material changes.
For construction chiral modified model channels with natural functional characteristics we suggested the method of “energy leveling” of tertiary channels structures with different amino acid sequences. This method we tested on potential-independent potassium channel KcsA, which is canonical pore-forming subunity of superfamily potassium membrane channels. Atom coordinates of natural L-amino acid channel KcsA we took from Protein Data Bank (Brookhaven National Laboratory, USA).
The given results show good accord of functional characteristics of natural and chiral modified model channel. This result gives an opportunity to use the suggested approach for structure construction of other axial-symmetrical membrane channels, and also it gives although a partial answer to the question of chiral purity origin of amino-acid residuum in proteins.
The practical significance of the given method is defined by a possibility of using D-amino-acid sequences for intended synthesis of model membrane channels with essential qualities