演題概要

ポスター発表

第2日　5月16日（木）　　P会場（多目的ホール）

2P-37　　PDF

親水性相互作用クロマトグラフィー質量分析法による哺乳類組織及び細胞に存在する内在性イノシトールポリ/ピロリン酸の検出と定量

(¹東海大支援セ・ ²東海大医・神経・ ³フライブルグ大・ ⁴ユニバーシティカレッジロンドン)
^o伊藤誠敏¹・ 藤井奈津子²・ 佐々木亜由美¹・ 田中政之¹・ Jessen, Henning³・ Saiardi, Adolfo⁴・ 永田栄一郎²

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.