On the Hydration State of Amino Acids and Their Derivatives at Different Ionization States: A Comparative Multinuclear NMR and Crystallographic Investigation
Figure 2
Dependence of the 17O chemical shift (ppm from H2O) of L-alanine and L-proline on the molar fraction X of DMSO at various pH values. (a) L-alanine at pH 7.4 (■) and pH 11.9 (□), (b) L-proline at pH 8.3 (■) and pH 13.0 (□), (c) L-alanine at pH 1.5, and (d) L-proline at pH 1.0. (Adapted, with permission, from Biochem. Biophys. Res. Commun. [9]. Copyright 1986, Academic Press, Inc.).
