Theoretical investigation of structure and energy of the protonated non-covalently bound diastereomeric complexes of biological molecules using DFT methods

SNIC 2018/5-51


SNAC Small

Principal Investigator:

Oleksii Rebrov


Stockholms universitet

Start Date:


End Date:


Primary Classification:

10302: Atom and Molecular Physics and Optics




Study of biomolecules in a gas phase represents a promising approach to investigate their structure and properties. The chirality phenomenon has now become a top-class subject for academic research as well as for pharmaceutical development. Nature uses chirality to maximize specificity of chemical interactions – most biomolecules are chiral and, as a result, different enantiomers of a compound may have substantially different biological effects such as pharmacokinetics, metabolism, toxicity, etc. Homochirality is believed to be not only a consequence of life but probably a precondition for it. An important and much discussed astrophysical question concerns the mechanism leading to the formation and processing of interstellar organic compounds and the role of different physical mechanisms in formation of different enantiomers. From another point of view the increasing demand in optically pure pharmaceuticals drives the need for efficient enantioselective, qualitative and quantitative analytical methods. The main goal of this project is investigation of biomolecules properties with an emphasize on chirality phenomenon. In the experiments performed by our group we have studied the stereo-dependence of reactions in gas phase that involve amino acids and amino acid inclusive diastereomeric complexes [1-4]. The theoretical model that can help to understand the mechanism of chiral discrimination in molecular reactions would be very beneficial for current study, applied science and industry, as well as for the fundamental questions of biological homochirality and stereospecific interactions. The molecular dynamics of proton bound diastereomeric complexes have been already done by our group for 4 amino acids of different properties, amino acids with sugar, and amino acids with alcohols. The structures of the lowest energy conformers have been determined. The DFT calculations are required to optimize obtained structures, determine the most stable complexes, investigate their characteristics and assign the stereo-dependent interactions. [1] Kulyk K., Rebrov O., Stockett, MH., Alexander JD., Zettergren H., Schmidt HT., Thomas RD., Cederquist H., Larsson M. High-energy collisions of protonated enantiopure amino acids with a chiral target gas. Int. J. Mass Spectrom. 388, 59–64 (2015) [2] Kulyk K, Rebrov O, Ryding M, Thomas RD, Uggerud E, Larsson M. Low-Energy Collisions of Protonated Enantiopure Amino Acids with Chiral Target Gases, J Am Soc Mass Spectrom 2017; 2686-2691. [3] Rebrov O, Kulyk K, Ryding M, Thomas RD, Uggerud E, Larsson M. Chirally sensitive collision induced dissociation of proton-bound diastereomeric complexes of tryptophan and 2-butanol. Chirality 2017; 29, 115–119. [4] Rebrov O, Ryding M, Thomas RD, Uggerud E, Larsson M; Non-covalently Bonded Diastereomeric Adducts of Amino Acids and (S)-1-Phenylethanol in Low-energy Dissociative Collisions. 2018 Manuscript.