Conformational dependence on pH in tripeptides.
From the 1H-NMR study of Tyr-Gly-Gly and Phe-Gly-Gly in H2O and 2H2O as a function of pH it follows that these tripeptides display at least two and probably three conformational zones. Under slow exchange conditions of the peptidic NH-protons, coupling constants 3J(NH, CaH) may be extracted as the probe. At higher pH values shift values and 3J(a, beta) of the side chain and the titration curves are indicative for these conformational alterations.
Conformational dependence on pH in tripeptides. From the 1H-NMR study of Tyr-Gly-Gly and Phe-Gly-Gly in H2O and 2H2O as a function of pH it follows that these tripeptides display at least two and probably three conformational zones. Under slow exchange conditions of the peptidic NH-protons, coupling constants 3J(NH, CaH) may be extracted as the probe. At higher pH values shift values and 3J(a, beta) of the side chain and the titration curves are indicative for these conformational alterations.