title: Hydrogen bond strengths in phosphorylated and sulfated amino acid residues.
abstract: Post-translational modification by the addition of an oxoanion functional group, usually a phosphate group and less commonly a sulfate group, leads to diverse structural and functional consequences in protein systems. Building upon previous studies of the phosphoserine residue (pSer), we address the distinct nature of hydrogen bonding interactions in phosphotyrosine (pTyr) and sulfotyrosine (sTyr) residues. We derive partial charges for these modified residues and then study them in the context of molecular dynamics simulation of model tripeptides and sulfated protein complexes, potentials of mean force for interacting residue pairs, and a survey of the interactions of modified residues among experimental protein structures. Overall, our findings show that for pTyr, bidentate interactions with Arg are particularly dominant, as has been previously demonstrated for pSer. sTyr interactions with Arg are significantly weaker, even as compared to the same interactions made by the Glu residue. Our work sheds light on the distinct nature of these modified tyrosine residues, and provides a physical-chemical foundation for future studies with the goal of understanding their roles in systems of biological interest.
authors.affiliation: Department of Chemistry and Biochemistry, Stern College for Women, Yeshiva University, New York, New York, USA. rappc@yu.edu
authors.forename: Chaya
authors.initials: C
authors.lastname: Rapp
authors.forename: Hadassa
authors.initials: H
authors.lastname: Klerman
authors.forename: Emily
authors.initials: E
authors.lastname: Levine
authors.forename: Christopher L
authors.initials: CL
authors.lastname: McClendon
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D001120:Arginine / Q000737:chemistry; D019295:Computational Biology / Q000379:methods; D030562:Databases, Protein; D018698:Glutamic Acid / Q000737:chemistry; D006801:Humans; D006860:Hydrogen Bonding; D056004:Molecular Dynamics Simulation; D010455:Peptides / Q000737:chemistry; D010710:Phosphates / Q000737:chemistry; D010766:Phosphorylation; D010768:Phosphoserine / Q000737:chemistry; D019000:Phosphotyrosine / Q000737:chemistry; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D011506:Proteins / Q000737:chemistry*; D012997:Solvents; D055672:Static Electricity; D014443:Tyrosine / Q000031:analogs & derivatives / Q000737:chemistry
chemical_list: D000596:Amino Acids; D010455:Peptides; D010710:Phosphates; D011506:Proteins; D012997:Solvents; D010768:Phosphoserine; D019000:Phosphotyrosine; C005662:tyrosine O-sulfate; D018698:Glutamic Acid; D014443:Tyrosine; D001120:Arginine