Structural determination of arginine-linked cisplatin complexes via IRMPD action spectroscopy: arginine binds to platinum via NO⁻ binding mode

Abstract

Cisplatin, (NH3)2PtCl2, has been known as a successful metal-based anticancer drug for more than half a century. Its analogue, Argplatin, arginine-linked cisplatin, (Arg)PtCl2, is being investigated because it exhibits reactivity...

Structural Determination of Lysine-Linked Cisplatin Complexes via IRMPD Action Spectroscopy: NNs and NO– Binding Modes of Lysine to Platinum Coexist

“…The structural sampling process employed here is similar to that reported in our previous investigation of the analogous Argplatin complexes. 25 Briefly, candidate structures for the [(Lys-H)PtCl 2 ] − and [(Lys)PtCl 2 +Na] + complexes were optimized using Gaussian 09 and the B3LYP/mDZP/def2-TZVP hybrid approach, where B3LYP is the density functional method, mDZP is the basis set used for Pt, and def2-TZVP the basis set employed for all other atoms. 24,25,43 All basis sets were acquired from the EMSL basis set exchange library.…”

“…However, if Lys binds to Pt via the NN s binding mode, the low cellular uptake would be easily understood. Previous gas-phase studies of the amino-acid-linked platinum complexes of glycine (Gly) and arginine (Arg) determined that Gly and Arg bind to Pt only via the backbone nitrogen and carboxylate oxygen atoms, i.e., the NO – binding mode. , However, if Lys binds to the Pt metal center only via the NO – binding mode, the reactivity of Lysplatin should be similar to that of Glyplatin and Argplatin, and the outstanding reactivity of Lysplatin observed in the screening of amino-acid-linked platinum complexes would not be easily explained …”

“…Previous gas-phase studies of the amino-acid-linked platinum complexes of glycine (Gly) and arginine (Arg) determined that Gly and Arg bind to Pt only via the backbone nitrogen and carboxylate oxygen atoms, i.e., the NO − binding mode. 24,25 However, if Lys binds to the Pt metal center only via the NO − binding mode, the reactivity of Lysplatin should be similar to that of Glyplatin and Argplatin, and the outstanding reactivity of Lysplatin observed in the screening of amino-acid-linked platinum complexes would not be easily explained. 19 In the present study, infrared multiple photon dissociation (IRMPD) action spectroscopy experiments complemented by computational predictions are used to reinvestigate the structure of Lysplatin in its deprotonated and sodiumcationized forms, [(Lys-H)PtCl 2 ] − and [(Lys)PtCl 2 +Na] + , to mimic different chemical environments.…”

Cation‐π Interactions between a Noble Metal and a Polyfunctional Aromatic Ligand: Ag+(benzylamine)

“…[29,30] In a recent report, cation-π complexes of Ag + with benzene, toluene and furan have been studied with ultraviolet laser photodissociation and photofragment imaging, providing new information on the cation-π bond energies. [31] IR ion spectroscopy has proven to be a valuable tool to shed light on the structural features of complexes of the noble metals silver, [17,[32][33][34][35][36][37][38][39][40] gold [41][42][43][44][45][46] and platinum, [47][48][49][50][51][52][53] with a variety of ligands yielding a wealth of valuable information such that only partial reference may be given here. It has been reported that complexation of Ag + with polycyclic aromatic hydrocarbons is accompanied by substantial charge transfer, emerging from the analysis of the IR bands of the complexes compared to those of the bare ligands.…”

Ligation Motifs in Zinc-Bound Sulfonamide Drugs Assayed by IR Ion Spectroscopy

“…IRMPD spectroscopy has been demonstrated to afford a valuable characterization of biologically active molecules and molecular complexes since its expansion as a structural diagnostic tool of mass-selected charged species [ 17 , 18 , 19 , 20 , 21 ]. In a considerable number of studies, including contributions from these authors, it has been applied to identify binding motifs and preferred geometries of transition metal complexes coordinating biomolecular ligands and targets [ 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ]. Zinc complexes of biomolecules have also been assayed [ 33 , 34 , 35 , 36 , 37 , 38 ].…”