Pressure dependence of side chain C-13 chemical shifts in model peptides Ac-Gly-Gly-Xxx-Ala-NH2

Author(s)

Erlach, Markus Beck ^{[1, 2]} ; Koehler, Joerg ^{[1, 2]} ; Crusca, Jr., Edson ^[3] ; Munte, Claudia E. ^{[4, 1, 2]} ; Kainosho, Masatsune ^[5] ; Kremer, Werner ^{[1, 2]} ; Kalbitzer, Hans Robert ^{[1, 2]}

Affiliation

^[1] Univ Regensburg, Inst Biophys & Phys Biochem, D-93040 Regensburg - Germany

^[2] Univ Regensburg, Ctr Magnet Resonanc, D-93040 Regensburg - Germany

^[3] So Paulo State Univ UNESP, Inst Chem, BR-14800060 Araraquara - Brazil

^[4] Univ Sao Paulo, Phys Inst Sao Carlos, BR-13566590 Sao Carlos, SP - Brazil

^[5] Tokyo Metropolitan Univ, Grad Sch Sci & Technol, 1-1 Minami Ohsawa, Hachioji, Tokyo 1920397 - Japan

• Document type: Journal article
• Source: Journal of Biomolecular NMR; v. 69, n. 2, p. 53-67, OCT 2017.
• Web of Science Citations: 3

Abstract

For evaluating the pressure responses of folded as well as intrinsically unfolded proteins detectable by NMR spectroscopy the availability of data from well-defined model systems is indispensable. In this work we report the pressure dependence of C-13 chemical shifts of the side chain atoms 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 a number of nuclei have a nonlinear dependence on pressure in the range from 0.1 to 200 MPa. The size of the polynomial pressure coefficients B (1) and B (2) is dependent on the type of atom and amino acid studied. For H-N, N and C-alpha the first order pressure coefficient B (1) is also correlated to the chemical shift at atmospheric pressure. The first and second order pressure coefficients of a given type of carbon atom 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 also are weakly correlated. The downfield shifts of the methyl resonances suggest that gauche conformers of the side chains are not preferred with pressure. The valine and leucine methyl groups in the model peptides were assigned using stereospecifically C-13 enriched amino acids with the pro-R carbons downfield shifted relative to the pro-S carbons. (AU)

• FAPESP's process: 10/12953-4 - Structural determination of the C-terminal domains of septins SEPT2 and SEPT4 and protein interaction with alpha-synuclein by NMR
• Grantee: Edson Crusca Junior
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 10/01362-5 - Interaction of proteins with lipidic microdomains and biological membrane models
• Grantee: Claudia Elisabeth Munte
• Support Opportunities: Regular Research Grants