Figure 5.

NOEsY spectra demonstrate “peptide dissection” of intact DM motif (A) into major and minor fragments: Zn-binding module (DM_Δ; B) and carboxy-terminal peptide (peptide DM-p; C). Shown are respective spectra in H₂O at 25°C and 600 MHz; mixing times were in each case 175 msec. Cross peaks from amide and aromatic protons (vertical scale, θ₂) and aliphatic protons (horizontal scale, θ₁) are shown. Boxed regions highlight unresolved envelope in intact DM domain (A) assigned to nascent carboxy-terminal helix (C); this feature is absent in spectrum of DM_Δ (B). Peptides were made 1.5 mm in 50 mm deuterated Tris-HCl (pH 6.5) in 90% H₂O and 10% D₂O. Spectra A and B also were obtained in presence of 4 mm ZnCl₂.