日本質量分析学会 第67回質量分析総合討論会

Abstract

Poster Presentations

Day 2, May 16(Thu.)  Room P (Multi-purpose Hall)

Hydrophilic Interaction Liquid Chromatography–Tandem Mass Spectrometry for the Quantitative Analysis of Mammalian-Derived Inositol Poly/Pyrophosphates

(1Tokai Univ. Sup. Centr, 2Tokai Univ. Dept. Neurol, 3Univ. of Freiburg, 4UCL)
oMasatoshi Ito1, Natsuko Fujii2, Ayumi Sasaki1, Masayuki Tanaka1, Henning Jessen3, Adolfo Saiardi4, Eiichiro Nagata2

Myo-inositol phosphates (InsPs) play an important role in a variety of physiological functions in animals and plants. Among the InsPs, inositol pyrophosphates such as diphosphoinositol pentakisphosphate (InsP7), a highly-phosphorylated InsP generated from inositol hexakisphosphate (InsP6) by InsP6 kinases, are implicated in the development of cancer and neurodegenerative disorders. However, their precise roles remains elusive due to a lack of direct and sensitive methods to quantitate their abundance in biological samples.
We have recently developed an analytical method whereby InsP6 and InsP7 can be directly and sensitively determined using tandem mass spectrometry coupled with hydrophilic interaction liquid chromatography (HILIC)1). A polymer-based amino HILIC column, but not those with other chemical functionalities such as unmodified silica and zwitterionic group, achieved chromatographic separation of these InsPs with minimal peak tailing. Using this method, we succeeded at determining not only the amount of InsP6 in C57BL/6J mouse brain but also the concentrations of these InsPs in HEK293 cells before and after InsP7 induction by the NaF treatment. Furthermore, this analysis revealed the presence of endogenous InsP7 in human peripheral blood cells. Further improvement of this method is currently underway to simultaneously detect InsP8, another inositol pyrophosphate engendered by the phosphorylation of InsP7.