Mass spectrometry assisted assignments of binding and cleavage sites of Zn(II) complex towards oxidized insulin B chain

The electrospray ionization mass spectrometry investigation showed that the binding sites of [ZnL]2+, where L is 2-[bis(2-aminoethyl)amino]ethanol, with oxidized insulin B chain are Phe1, His5 and Arg22, which lead to the selective cleavages of the peptide bonds at Phe1-Val2, His5-Leu6, Glu21-Arg22, and Arg22-Gly23 of oxidized insulin B chain.