Figure 2.

HSQC-NMR Spectroscopic Analysis of CaM-Peptide Interactions.

Overlaid spectra of uniformly ¹⁵N-labeled CaM in the absence (black) or presence (red) of equimolar peptide. In all assays, spectra of 0.2 mM ¹⁵N-CaM were collected in either Ca²⁺ buffer (10 mM HEPES, 100 mM NaCl, and 5 mM CaCl₂, pH 7.5) or apo buffer (10 mM HEPES, 100 mM NaCl, and 1 mM EGTA, pH 7.5), as indicated. Spectra of Ca²⁺/CaM (A) or apoCaM +/− NT peptide (B). Spectra of Ca²⁺/CaM (C) or apoCaM +/− IQ peptide (D). Spectra of Ca²⁺/CaM (E) or apoCaM +/− CT peptide (F).