title: Synthesis and application of a Sec2-containing oligopeptide for method evaluation purposes in selenium speciation.
abstract: Sec(2)-containing oligopeptide was synthesized directly from Sec(2) with the traditional liquid phase peptide synthesis without addressing the usually applied and complex solid phase (SPPS) protocol driving through a protected Sec residue and site-oriented oxidation into a diselenide bridge. Effective solubilization of Sec(2) in dimethylformamide and its pH-controlled access to pentachlorophenol-activated peptides to couple with were of crucial importance to achieve good yield (>50%) of synthesis, monitored by HPLC-UV, SEC-ICP-MS and HPLC-ESI-MS techniques. To demonstrate the possible application of the new compound, (Boc-GGFG)-Sec(2)-(Boc-GGFG) (m/z 1173.3, [M+H](+)), it was utilized to compare the effect of the two most addressed sample preparation techniques, i.e., methanesulphonic acid (MSA) based digestion and proteolytic digestion with protease XIV, on the Sec residue. The study revealed that the use of MSA resulted in the decomposition of Sec even after derivatization with iodoacetamide.
authors.affiliation: Department of Applied Chemistry, Corvinus University of Budapest, 29-33. Villányi út, 1118 Budapest, Hungary. mihaly.dernovics@uni-corvinus.hu
authors.forename: Mihály
authors.initials: M
authors.lastname: Dernovics
authors.forename: Andrea
authors.initials: A
authors.lastname: Vass
authors.forename: Anikó
authors.initials: A
authors.lastname: Németh
authors.forename: Anna
authors.initials: A
authors.lastname: Magyar
mesh_terms: D000595:Amino Acid Sequence; D053000:Analytic Sample Preparation Methods / Q000379:methods*; D060326:Chemistry Techniques, Synthetic; D009842:Oligopeptides / Q000138:chemical synthesis* / Q000737:chemistry*; D011402:Pronase / Q000378:metabolism; D059748:Proteolysis; D015203:Reproducibility of Results; D012643:Selenium / Q000032:analysis* / Q000737:chemistry*; D017279:Selenocysteine / Q000737:chemistry* / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D013441:Sulfinic Acids / Q000737:chemistry
chemical_list: D009842:Oligopeptides; D013441:Sulfinic Acids; D017279:Selenocysteine; C053310:methanesulfinic acid; D011402:Pronase; D012643:Selenium