Skip to main content
. Author manuscript; available in PMC: 2009 Oct 6.
Published in final edited form as: Nat Struct Mol Biol. 2006 Aug 13;13(9):831–838. doi: 10.1038/nsmb1132

Figure 2.

Figure 2

Effect of the sequential cAMP binding on the structure of CAPN assessed by chemical shift mapping. The chemical shift is a highly sensitive probe of the local electronic environment of the nucleus and, thus, provides very useful information about the chemical structure of the protein. The combined chemical shift change of a particular residue upon ligand binding was calculated as: Δδ=(ωHNΔδHN)2+(ωNΔδN)2+(ωCαΔδCα)2+(ωCβΔδCβ)2+(ωCOΔδCO)2, where ωi denotes the weight factor of nucleus i. ωhn= 1, ωn= 0.154, ωcα= ωcβ =0.276 and ωco= 0.341 (ref. 43). The color code used to display Δδ (in ppm) is as follows: Δδ ∼ 0, dark blue; 0.02 < Δδ < 0.08, light blue; 0.08 < Δδ < 0.2, magenta; 0.2 < Δδ < 0.4, red; 0.4 < Δδ < 0.6, orange; Δδ > 0.7, yellow. Δδ for the cAMP2-CAPN complex reflects the binding effect of the second cAMP molecule on the cAMP1-CAPN complex. Proline residues are colored white.