Trace element speciation by ICP-MS in large biomolecules and its potential for proteomics

Abstract

Latest studies on the chemical association of trace elements to large biomolecules and their importance on the bioinorganic and clinical fields are examined. The complexity of the speciation of metal-biomolecules associations in various biological fluids is stressed. Analytical strategies to tackle speciation analysis and the-state-of-the-art of the instrumentation employed for this purpose are critically reviewed. Hyphenated techniques based on coupling chromatographic separation techniques with ICP-MS detection are now established as the most realistic and potent analytical tools available for real-life speciation analysis. Therefore, the status and potential of metal and semimetals elemental speciation in large biocompounds using ICP-MS detection is mainly focused here by reviewing reported metallo-complexes separations using size-exclusion (SEC), ion-exchange (IE), reverse phase chromatography (RP) and capillary electrophoresis (CE). Species of interest include coordination complexes of metals with larger proteins (e.g. in serum, breat milk, etc.) and metallothioneins (e.g. in cytosols from animals and plants) as well as selenoproteins (e.g. in nutritional supplements), DNA-cisplatin adducts and metal/semimetal binding to carbohydrates. An effort is made to assess the potential of present trace elements speciation knowledge and techniques for "heteroatom-tagged" (via ICP-MS) proteomics.

Capillary electrophoresis hyphenated to inductively coupled plasma‐mass spectrometry: A novel approach for the analysis of anticancer metallodrugs in human serum and plasma

“…Unfortunately, the most abundant isotope of sulfur, i.e. 32 H, but quantification is still possible to a certain extent. Due to the background noise caused by these interferences, only the trace of the most abundant protein in human plasma, albumin (containing 42 S atoms, www.expasy.org), can be followed in real-world samples by the current approach.…”

“…Recently the focus has shifted towards mass spectrometric detection such as ESI-MS [25,26] and inductively coupled plasma (ICP)-MS [27][28][29][30], opening new possibilities for the characterization of metallodrug interactions with biological targets [7,31]. Especially ICP-MS, the unrivalled detector in terms of specificity and LOD of metals bound to biomolecules, seems best-suited for quantification of adducts, especially if only present in traces [32,33].…”

Comparative Studies Involving Transgenic and Non-Transgenic Soybean: What is Going On?

“…It is robust for multielementar determinations, allowing to reach extremely low detection limits and giving isotopic information for identification and quantification of the species, besides being easily coupled to classic separation techniques, such as HPLC, readily realized since the chromatographic flow (0.5-1.0 mL min -1 ) is compatible to common ICP-MS nebulizers [97,99].…”

New Methodologies for Assessing the Presence and Ecological Effects of Pesticides in Doñana National Park (SW Spain)

“…These hybrid techniques allow the measurement of metal species in cytosolic extracts using the heteroelement as a marker (Sanz-Medel, 2003). The couplings based on size exclusion (SEC-ICP-MS) permit a rapid screening through the molecular mass of metalmolecules (Szpunar, 2004(Szpunar, , 2005Sanz-Medel et al, 2003;González-Fernández et al, 2008b), although purification of the peaks requires a second chromatographic separation by ionic exchange, reverse phase or hydrophobic interaction, to identify the molecule (Arias-Borrego et al, 2008). Other alternatives use CE-ICP-MS couplings, gel electrophoresis with laser ablation and ICP-MS detection, or detection of the metal by spot digestion and ICP-MS analysis (Sussulini et al, 2007;Monicou & Lobinski, 2008).…”