Bovine pancreatic trypsin inhibitor (BPTI; Figure 6.25) contains six cysteine residues that form three disulfide bonds in the native structure of BPTI. Suppose BPTI is reduced and unfolded in urea (as illustrated for RNase A in Figure 6.22). If the reduced unfolded protein were oxidized prior to the removal of the urea, what fraction of the resulting mixture would you expect to possess native disulfide bonds?

Figure 6.25

 Figure 6.22

Transcribed Image Text:

Amino acid sequence: Three disulfide bonds formed by side chains of the six cysteines Covalent disulfide bond connecting two Cys residues. N EDCMRTCGG RPDFCLEPPYTGPCKARIIRYFYNAKAGLCQTFVYGGERAKRNNFKSAEDCMRTCGGA