Acknowledgements
Authors would like to thank Prof Alexei V. Finkelstein and Prof Alexander V. Efimov, Institute of Protein Research, Russian Academy of Sciences, for very useful discussion. Numerical calculations were performed on the hybrid supercomputer K-60 at the Keldysh Institute of Applied Mathematics, Russian Academy of Sciences. The authors appreciate very much the excellent work of the staff accompanying our computing experiment.
Disclosure statement
The authors report that there are no competing interests to declare.