title: Theoretical Studies of Interactions between O-Phosphorylated and Standard Amino-Acid Side-Chain Models in Water.
abstract: Phosphorylation is a common post-translational modification of the amino-acid side chains (serine, tyrosine, and threonine) that contain hydroxyl groups. The transfer of the negatively charged phosphate group from an ATP molecule to such amino-acid side chains leads to changes in the local conformations of proteins and the pattern of interactions with other amino-acid side-chains. A convenient characteristic of the side chain-side chain interactions in the context of an aqueous environment is the potential of mean force (PMF) in water. A series of umbrella-sampling molecular dynamic (MD) simulations with the AMBER force field were carried out for pairs of O-phosphorylated serine (pSer), threonine (pThr), and tyrosine, (pTyr) with natural amino acids in a TIP3P water model as a solvent at 298 K. The weighted-histogram analysis method was used to calculate the four-dimensional potentials of mean force. The results demonstrate that the positions and depths of the contact minima and the positions and heights of the desolvation maxima, including their dependence on the relative orientation depend on the character of the interacting pairs. More distinct minima are observed for oppositely charged pairs such as, e.g., O-phosphorylated side-chains and positively charged ones, such as the side-chains of lysine and arginine.
authors.affiliation: †Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-308 Gdańsk, Poland.
authors.forename: Marta
authors.initials: M
authors.lastname: Wiśniewska
authors.affiliation: ‡Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, Kładki 24, 80-822 Gdańsk, Poland.
authors.forename: Emil
authors.initials: E
authors.lastname: Sobolewski
authors.affiliation: ‡Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, Kładki 24, 80-822 Gdańsk, Poland.
authors.forename: Stanisław
authors.initials: S
authors.lastname: Ołdziej
authors.affiliation: †Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-308 Gdańsk, Poland.
authors.forename: Adam
authors.initials: A
authors.lastname: Liwo
authors.affiliation: §Baker Laboratory of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301.
authors.forename: Harold A
authors.initials: HA
authors.lastname: Scheraga
authors.affiliation: †Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-308 Gdańsk, Poland.
authors.forename: Mariusz
authors.initials: M
authors.lastname: Makowski
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D006860:Hydrogen Bonding; D056004:Molecular Dynamics Simulation; D010766:Phosphorylation; D012997:Solvents / Q000737:chemistry; D014867:Water / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D012997:Solvents; D014867:Water