Critical assessment of different methods for quantitative measurement of metallodrug-protein associations

Abstract

Quantitative screening for potential drug–protein binding is an essential step in developing novel metal-based anticancer drugs. ICP–MS approaches are at the core of this task; however, many applications lack in the capability of large-scale high-throughput screenings and proper validation. In this work, we critically discuss the analytical figures of merit and the potential method-based quantitative differences applying four different ICP–MS strategies to ex vivo drug–serum incubations. Two candidate drugs, more specifically, two Pt(IV) complexes with known differences of binding affinity towards serum proteins were selected. The study integrated centrifugal ultrafiltration followed by flow injection analysis, turbulent flow chromatography (TFC), and size exclusion chromatography (SEC), all combined with inductively coupled plasma-mass spectrometry (ICP–MS). As a novelty, for the first time, UHPLC SEC-ICP–MS was implemented to enable rapid protein separation to be performed within a few minutes at > 90% column recovery for protein adducts and small molecules. Graphical abstractQuantitative screening for potential drug–protein binding is an essential step in developingnovel metal-based anticancer drugs Electronic supplementary materialThe online version of this article (10.1007/s00216-018-1328-8) contains supplementary material, which is available to authorized users.

Binding Kinetics of Ruthenium Pyrithione Chemotherapeutic Candidates to Human Serum Proteins Studied by HPLC-ICP-MS

“…It provides data for the elucidation of the mechanism of antitumor therapy, the behaviour of the intact drug, its biotransformation in clinical samples at physiologically relevant concentrations and, as the final goal, its dosage adjustment. This information can be largely acquired by a speciation analysis [22][23][24][25][26][27]. For a metalloprotein speciation analysis, the most frequently applied was high-performance liquid chromatography (HPLC) hyphenated to inductively coupled plasma mass spectrometry (ICP-MS) detector.…”

The separation sciences, the front end to proteomics: An historical perspective

“…In another example, a number of different methods were assessed for quantitative measurement of metallodrug–protein interactions. Centrifugal ultrafiltration followed by flow injection analysis, TFC, and SEC were combined with inductively coupled plasma‐mass spectrometry (Galvez et al, 2018).…”

N-Heterocyclic Carbene Platinum(IV) as Metallodrug Candidates: Synthesis and 195Pt NMR Chemical Shift Trend

“…In addition to investigating the redox potential of Pt(IV) complexes, 195 Pt NMR is a valuable technique for the fast and standardized characterization of platinum complexes to complement routine characterization [ 10 , 11 , 12 , 13 , 14 , 15 ]. Moreover, investigating the chemical shift in 195 Pt NMR is a prerequisite to further enable mechanistic and pharmacokinetic investigations of the platinum complex and its metabolites using 195 Pt spectroscopy [ 16 ], as an alternative to LA-ICP-MS [ 17 ] or X-ray-based techniques [ 18 , 19 , 20 , 21 ]. Of note, Huynh et al recently suggested the direct correlation of the platinum chemical shift in 195 Pt NMR to both the electronic density at the platinum center and the electronic donation of the coordination sphere, in particular in the case of N -heterocyclic carbene (NHC)-platinum complexes [ 22 , 23 , 24 ].…”