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Mass spectrometry assisted assignments of binding and cleavage sites of copper(II) and platinum(II) complexes towards oxidized insulin B chain
Author(s) -
Hong Jin,
Miao Ren,
Zhao Chunmei,
Jiang Jiang,
Tang Huiwei,
Guo Zijian,
Zhu Longgen
Publication year - 2006
Publication title -
journal of mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 1076-5174
DOI - 10.1002/jms.1065
Subject(s) - chemistry , copper , cleavage (geology) , platinum , mass spectrometry , stereochemistry , chromatography , organic chemistry , catalysis , geotechnical engineering , fracture (geology) , engineering
Interaction of cis ‐[Pt(en)(H 2 O) 2 ] 2+ and [CuL(H 2 O)] 2+ , where L is 2‐[bis(2‐aminoethyl)amino]ethanol, with oxidized insulin B chain in molar ratio of 1 : 1, 1 : 2 and 1 : 3 at pH 2.5 and 40 °C has been investigated by electrospray ionization mass spectrometry (ESI‐MS) and tandem mass spectrometry (MS/MS). The results show that the binding sites of the two complexes with oxidized insulin B chain are terminal NH 2 , imidazole groups of His5 and His10. The hydrolytic cleavage studies show that the [CuL(H 2 O)] 2+ , upon a pendant hydroxyl group of the ligand, selectively cleaves the peptide bonds at Gly8–Ser9, Asn3–Gln4 and Phe1–Val2, and the cis ‐[Pt(en)(H 2 O) 2 ] 2+ only cleaves the peptide bond at His10–Leu11. This is the first report of cis ‐[Pt(en)(H 2 O) 2 ] 2+ ‐promoted cleavage of His–X peptide bond. Copyright © 2006 John Wiley & Sons, Ltd.