title: Pressure dependence of backbone chemical shifts in the model peptides Ac-Gly-Gly-Xxx-Ala-NH2.
abstract: For a better understanding of nuclear magnetic resonance (NMR) detected pressure responses of folded as well as unstructured proteins the availability of data from well-defined model systems are indispensable. In this work we report the pressure dependence of chemical shifts of the backbone atoms (1)H(α), (13)C(α) and (13)C' in the protected tetrapeptides Ac-Gly-Gly-Xxx-Ala-NH2 (Xxx one of the 20 canonical amino acids). Contrary to expectation the chemical shifts of these nuclei have a nonlinear dependence on pressure in the range from 0.1 to 200 MPa. The polynomial pressure coefficients B 1 and B 2 are dependent on the type of amino acid studied. The coefficients of a given nucleus show significant linear correlations suggesting that the NMR observable pressure effects in the different amino acids have at least partly the same physical cause. In line with this observation the magnitude of the second order coefficients of nuclei being direct neighbors in the chemical structure are also weakly correlated.
authors.affiliation: Institute of Biophysics and Physical Biochemistry and Centre of Magnetic Resonance in Chemistry and Biomedicine, University of Regensburg, 93040, Regensburg, Germany.
authors.forename: Markus Beck
authors.initials: MB
authors.lastname: Erlach
authors.affiliation: Institute of Biophysics and Physical Biochemistry and Centre of Magnetic Resonance in Chemistry and Biomedicine, University of Regensburg, 93040, Regensburg, Germany.
authors.forename: Joerg
authors.initials: J
authors.lastname: Koehler
authors.affiliation: Physics Institute of São Carlos, University of São Paulo, São Carlos, 13566-590, Brazil.
authors.forename: Edson
authors.initials: E
authors.lastname: Crusca
authors.affiliation: Institute of Biophysics and Physical Biochemistry and Centre of Magnetic Resonance in Chemistry and Biomedicine, University of Regensburg, 93040, Regensburg, Germany.
authors.forename: Werner
authors.initials: W
authors.lastname: Kremer
authors.affiliation: Physics Institute of São Carlos, University of São Paulo, São Carlos, 13566-590, Brazil.
authors.forename: Claudia E
authors.initials: CE
authors.lastname: Munte
authors.affiliation: Institute of Biophysics and Physical Biochemistry and Centre of Magnetic Resonance in Chemistry and Biomedicine, University of Regensburg, 93040, Regensburg, Germany. hans-robert.kalbitzer@biologie.uni-regensburg.de.
authors.forename: Hans Robert
authors.identifier: 0000-0002-6514-2355
authors.initials: HR
authors.lastname: Kalbitzer
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008956:Models, Chemical; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D010455:Peptides / Q000737:chemistry*; D011312:Pressure
chemical_list: D000596:Amino Acids; D010455:Peptides
keywords: High pressure; NMR; Peptide; Random coil