Mass Spectrometric Determination of Zn²⁺ Binding/Dissociation Constant for Zinc Finger Peptides

Abstract

:In the present study, we proposed a simple ESI-MS model for determining Zn 2+ binding (or dissociation) constants for zinc finger peptides (ZFPs) with a unique ββα fold consensus. The ionization efficiency (response) factors for this model, i.e., α and β, could be determined for ZiCo ZFP with a known Zn 2+ binding constant. We could determine the binding constants for other ZFPs assuming those with a ββα consensus conformation have the same α/β response ratio. In general, the ZPF dissociation constants exhibited K d values of 10 0-9 M, while K d values for a negative control non-specific Zn 2+peptides were high, e.g., 5.5×10 -6 M and 4.3×10 -4 M for BBA1 and melittin, respectively.

Soft Ionization of Metallo-Mefenamic Using Electrospray Ionization Mass Spectrometry

“…18 ESI-MS can also be used for metallodrug-protein interactions 19 and for labile drugs. 20 ESI-MS has been employed to determine the binding or dissociation constants of zinc finger peptides (ZFPs), 21 to characterize a Ru(III) anticancer drug, 22 for Protein metalation processes, 23 and also to characterize antiproliferative activity 24 and cytotoxic metallodrugs. 25 A review of the applications of hyphenated techniques for metal-based pharmaceuticals has been published.…”