A growth type pathway for improving the folding of BPTI.

The oxidative folding of the protein bovine pancreatic trypsin inhibitor (BPTI) with oxidized dithiothreitol or glutathione has served as a paradigm for protein folding but could take weeks at physiological pH because of the need to escape from kinetic traps a rearrangement type pathway. The two major kinetic traps are called N' and N* and contain two of the three native disulfide bonds, which occur between residues 5 and 55, 30 and 51, and 14 and 38. N' is missing the disulfide bond between residues 5 and 55 while N* is missing the disulfide bond between residues 30 and 51.