TABLE 2.
Z is free Cys modified with 4-vinylpyridine.
The location of the disulfide bond is deduced from the modification experiment with 2-bromoethylamine and NEM (see text).
C* is the S-2-aminoethylcysteine generated after treatment with 2-bromoethylamine; this residue is now a recognition site for trypsin that was cleaved on the C-terminal side of C*, proving the location of the disulfide bond between C22 and C127.