Accurate Quantification of Selenoprotein P (SEPP1) in Plasma Using Isotopically Enriched Seleno-peptides and Species-Specific Isotope Dilution with HPLC Coupled to ICP-MS/MS
| Autor: | Christian L. Deitrich, Paola Fisicaro, Susana Cuello-Nuñez, Frank Attila Torma, Diana Kmiotek, Heidi Goenaga-Infante, Maria Estela Del Castillo Busto |
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| Rok vydání: | 2016 |
| Předmět: |
SEPP1
Indicator Dilution Techniques chemistry.chemical_element Peptide Isotope dilution 010402 general chemistry 01 natural sciences High-performance liquid chromatography Analytical Chemistry Matrix (chemical analysis) Selenium Isotopes Limit of Detection Tandem Mass Spectrometry Selenoprotein P Humans Amino Acid Sequence Inductively coupled plasma mass spectrometry Chromatography High Pressure Liquid chemistry.chemical_classification Chromatography 010401 analytical chemistry 0104 chemical sciences chemistry Peptides |
| Zdroj: | Analytical Chemistry. 88:6357-6365 |
| ISSN: | 1520-6882 0003-2700 |
| DOI: | 10.1021/acs.analchem.6b00715 |
| Popis: | A novel strategy for the absolute quantification of selenium (Se) included in selenoprotein P (SEPP1), an important biomarker for human nutrition and disease, including diabetes and cancer, is presented here for the first time. It is based on the use of species-specific double isotope dilution mass spectrometry (SSIDA) in combination with HPLC-ICP-MS/MS for the determination of protein bound Se down to the peptide level in a complex plasma matrix with a total content of Se of 105.5 μg kg(-1). The method enabled the selective Se speciation analysis of human plasma samples without the need of extensive cleanup or preconcentration steps as required for traditional protein mass spectrometric approaches. To assess the method accuracy, two plasma reference materials, namely, BCR-637 and SRM1950, for which literature data and a reference value for SEPP1 have been reported, were analyzed using complementary hyphenated methods and the species-specific approach developed in this work. The Se mass fractions obtained via the isotopic ratios (78)Se/(76)Se and (82)Se/(76)Se for each of the Se-peptides, namely, ENLPSLCSUQGLR (ENL) and AEENITESCQUR (AEE) (where U is SeCys), were found to agree within 2.4%. A relative expanded combined uncertainty (k = 2) of 5.4% was achieved for a Se (as SEPP1) mass fraction of approximately 60 μg kg(-1). This work represents a systematic approach to the accurate quantitation of plasma SEPP1 at clinical levels using SSIDA quantification. Such methodology will be invaluable for the certification of reference materials and the provision of reference values to clinical measurements and clinical trials. |
| Databáze: | OpenAIRE |
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