Figure 4: Plot of the 14 N (28.9 MHz) (a) and 17O (48.8 MHz) (b) line widths, , of Table 1 of the protein amino acids versus their molecular weights, MW: (♦) pH 0.5, (•) pH 6.0. All lines correspond to a nonlinear least squares fit of the experimental points of Table 1 according to (7). Dotted lines indicate the difference in MW for the same values. (Reprinted, with permission, from J. Magn. Reson. . Copyright 2003, by Elsevier Inc.).