Binding Properties of Copper(II)-Human Amylin Complexes Revealed by Laser Ablation Electrospray Ionization Mass Spectrometry

摘要

LAESI-IMS-MS effectively analyzed metal-peptide complexes in a rapid manner, revealing information about composition, binding domain, and kinetics. Limited amounts of peptide were required, with no pretreatment needed. The formation of the Cu(II)-amylin complex is completed in less than 24 h. Cu(II) binding saturates at ～2:1 copper:amylin ratio. LAESI-MS/MS of Cu(II)-hA narrowed the Cu(II) binding domain to residues 18-25. Cu(II) adducts were detected despite a point mutation of amylin (H18A), indicating that histidine-18 is not a requirement for copper binding. See the initial binding domain in red below.