Verification of the structure of selenophosphate

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K14991
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Environmental and hygienic pharmacy
• Research Institution: Chiba University
• Principal Investigator: Ogra Yasumitsu 千葉大学, 大学院薬学研究院, 教授 (40292677)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: セレン / セレノリン酸 / スペシエーション / ICP-MS

Outline of Final Research Achievements

Selenocysteine (Sec) is known as the 21st amino acid, and is required for an active center of several selenoproteins. Sec is biosynthesized on a tRNA charging serine, i.e., the hydroxyl group in serine is substituted to a selenol group from a donor of selenium (Se). Selenophosphate is proposed as the Se donor, however, the identification of selenophosphate is tenuous. The aim of this study is to verify the structure of selenophosphate by unambiguous analytical techniques. Selenophosphate was chemically synthesized. The NMR spectrum of chemically synthesized selenophosphate was not identical to the Se donor synthesized by selenophosphate synthetase 2 or Sel D which was an orthologue of SPS2. This suggests that selenophosphate is not the Se donor. We prepared mutant SPS2 which had a substitution of Sec to cysteine. Recombinant SPS2U60C will be used for the synthesis of Se donor in vitro, and the structure of Se donor will be concretely identified by several mass spectrometry.

Free Research Field

毒性学