caa a22 4500 477136516 CHVBK 20180405111719.0 cr unu---uuuuu 170330e19970601xx s 000 0 eng 10.1023/A:1018334207887 doi (NATIONALLICENCE)springer-10.1023/A:1018334207887 Temperature dependence of 1H chemical shifts in proteins [Elektronische Daten] [Nicola Baxter, Michael Williamson] Temperature coefficients have been measured by 2D NMR methods forthe amide and CαH proton chemical shifts in two globularproteins, bovine pancreatic trypsin inhibitor and hen egg-white lysozyme.The temperature-dependent changes in chemical shift are generally linear upto about 15° below the global denaturation temperature, and the derivedcoefficients span a range of roughly −16 to +2 ppb/K for amide protonsand −4 to +3 ppb/K for CαH. The temperaturecoefficients can be rationalized by the assumption that heating causesincreases in thermal motion in the protein. Precise calculations oftemperature coefficients derived from protein coordinates are not possible,since chemical shifts are sensitive to small changes in atomic coordinates.Amide temperature coefficients correlate well with the location of hydrogenbonds as determined by crystallography. It is concluded that a combined useof both temperature coefficients and exchange rates produces a far morereliable indicator of hydrogen bonding than either alone. If an amide protonexchanges slowly and has a temperature coefficient more positive than−4.5 ppb/K, it is hydrogen bonded, while if it exchanges rapidly andhas a temperature coefficient more negative than −4.5 ppb/K, it is nothydrogen bonded. The previously observed unreliability of temperaturecoefficients as measures of hydrogen bonding in peptides may arise fromlosses of peptide secondary structure on heating. Kluwer Academic Publishers, 1997 1H NMR nationallicence Chemical shift temperature coefficients nationallicence Amide exchange nationallicence Hydrogen bonds nationallicence Baxter Nicola Krebs Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, S10 2TN, Sheffield, U.K aut Williamson Michael Krebs Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, S10 2TN, Sheffield, U.K aut Journal of Biomolecular NMR Kluwer Academic Publishers 9/4(1997-06-01), 359-369 0925-2738 9:4<359 1997 9 10858 https://doi.org/10.1023/A:1018334207887 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1018334207887 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Baxter Nicola Krebs Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, S10 2TN, Sheffield, U.K aut NATIONALLICENCE 700 1- Williamson Michael Krebs Institute, Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, S10 2TN, Sheffield, U.K aut NATIONALLICENCE 773 0- Journal of Biomolecular NMR Kluwer Academic Publishers 9/4(1997-06-01), 359-369 0925-2738 9:4<359 1997 9 10858 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer