Figure 1.

Overlaid ¹H,¹⁵N HSQC spectra of unphosphorylated [¹⁵N,¹³C]MAP2c (blue), and [¹⁵N,¹³C]MAP2c phosphorylated by PKA for 24 h (red). The well-resolved peaks of phosphorylated residues (pSer-184, pSer-189, pThr-220, and pSer-435) at proton frequencies downfield from 8.6 ppm and of their neighbors (Arg-221 and Ser-222) are labeled. Bottom, close-up of the region of phosphorylated residues plotted with a lowered signal threshold level to show minor peaks. pX, this peak could not be assigned.