Fractionation of selenium-containing proteins in serum by multiaffinity liquid chromatography before size-exclusion chromatography-ICPMS.
Immunoaffinity chromatography has been investigated for fractionation of serum into selenoalbumin and true selenoproteins. Among several albumin-depletion kits tested, a multiaffinity column specifically binding albumin and five other major serum proteins provided the best results. It extracted ca 95% of both albumin and selenoalbumin, which enabled interference-free determination of glutathione peroxidase, selenoprotein P, and selenoalbumin by size-exclusion chromatography combined with inductively coupled plasma mass spectrometry (SEC-ICPMS). The efficiency of the multiaffinity column did not vary over a period of 18 months. The purity of fractions separated by immunoaffinity LC was confirmed by elution-volume matching with standards in SEC-ICPMS and by selenopeptide mapping in capillary HPLC-ICPMS. Quantification of the selenium distribution among the different proteins in human serum from a control group and from a person on a selenium-rich diet revealed that 67% of the supplemented selenium was incorporated into albumin, 30% into glutathione peroxidase, and 3% into selenoprotein P.
Palacios
Oscar
O
Equipe de Chimie Analytique Bio-inorganique, CNRS UMR 5034, Hélioparc, 2, av. Pr. Angot, 64053, Pau, France.
Ruiz Encinar
Jorge
J
Schaumlöffel
Dirk
D
Lobinski
Ryszard
R
D000418:Albumins / Q000378:metabolism; D000818:Animals; D001798:Blood Proteins / Q000737:chemistry* / Q000302:isolation & purification; D016022:Case-Control Studies; D002417:Cattle; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004032:Diet; D005979:Glutathione Peroxidase / Q000032:analysis; D006801:Humans; D012643:Selenium / Q000008:administration & dosage / Q000097:blood*; D051140:Selenoproteins / Q000032:analysis; D012710:Serum Albumin, Bovine / Q000032:analysis
D000418:Albumins; D001798:Blood Proteins; D051140:Selenoproteins; D012710:Serum Albumin, Bovine; D005979:Glutathione Peroxidase; D012643:Selenium