¹H, ¹³C, and ¹⁵N backbone resonance assignments of the porcine pepsin and porcine pepsin complexed with pepstatin.

Pepsin is formed as the zymogen, pepsinogen, which includes an additional 44 residue prosegment (PS) on the N-terminus. Upon acidification (pH <3) the PS is removed, yielding active pepsin. The PS is critical to such processes as the initiation of correct folding and protein stability. In the present study, the NMR assignments of the 34.6 kDa native porcine pepsin and porcine pepsin complexed with pepstatin are reported in order to obtain structural information regarding PS-catalyzed protein folding. Such information would contribute to a better understanding of the nature of folding/unfolding energy barrier of pepsin and other aspartic proteases.