... ratios: at a : Fe2+ ⁄ protein ratio, the resonances of Arg20, Asp22 and Asp23 disappeared, and the resonance of Leu21 shifted At a : ratio, the resonances of residues 19 and 44 also disappeared, ... spectrum of CyaY, but the most striking consequence of the addition was the total disappearance of specific resonances without the concomitant appearance of other signals in other parts of the spectrum ... water molecules (1.7 A and 1.9 A) (Fig 4E) In ˚ M5, the side chains of Asp76 (1.9 A) and Asp27 ˚ (2.4 A) of a symmetry-related molecule and four water ˚ ˚ ˚ ˚ molecules (1.9 A, 2.1 A, 3.1 A and...