Site-specifically cleavage of oxidized insulin B chain with Zn(II) ion studied by electrospray ionization mass spectrometry

The electrospray ionization mass spectrometry and tandem mass spectrometry investigation showed that the binding sites of Zn2+ with oxidized insulin B chain are His 5, His 10, and Arg 22, which lead to the selective cleavages of the peptide bonds at Asn 3-Gln 4, His 5-Leu 6, Gly 8-Ser 9, and Glu 21-Arg 22 of oxidized insulin B chain.