Figure 4.

A NOE correlation indicates a distance lower than 6 Angströms between the Ha proton of pamoic acid and the amide proton of the 8 kDa domain Ile69. a. Structure of pamoic acid with proton symbols, as used in the text. b. Two strips of 3D NOESY-HSQC spectrum corresponding to the Ile69 amide proton. The first strip was recorded without pamoic acid and the second in the presence of equimolar pamoic acid concentration. On the second strip, an additional crosspeak, orange-framed, appeared at 8,65 ppm. This crosspeak revealed an intermolecular NOE between the Ha pamoic acid proton and the amide proton of the 8 kDa domain Ile69.