Analysis of inositol phosphate metabolism by capillary electrophoresis electrospray ionization mass spectrometry.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 33247133.
- Also identified by DOI 10.1038/s41467-020-19928-x and PMC identifier 7695695.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The analysis of myo-inositol phosphates (InsPs) and myo-inositol pyrophosphates (PP-InsPs) is a daunting challenge due to the large number of possible isomers, the absence of a chromophore, the high charge density, the low abundance, and the instability of the esters and anhydrides. Given their importance in biology, an analytical approach to follow and understand this complex signaling hub is desirable. Here, capillary electrophoresis (CE) coupled to electrospray ionization mass spectrometry (ESI-MS) is implemented to analyze complex mixtures of InsPs and PP-InsPs with high sensitivity. Stable isotope labeled (SIL) internal standards allow for matrix-independent quantitative assignment. The method is validated in wild-type and knockout mammalian cell lines and in model organisms. SIL-CE-ESI-MS enables the accurate monitoring of InsPs and PP-InsPs arising from compartmentalized cellular synthesis pathways, by feeding cells with either [<sup>13</sup>C<sub>6</sub>]-myo-inositol or [<sup>13</sup>C<sub>6</sub>]-D-glucose. In doing so, we provide evidence for the existence of unknown inositol synthesis pathways in mammals, highlighting the potential of this method to dissect inositol phosphate metabolism and signalling.
Medical subject headings
- Electrophoresis, Capillary
- Inositol Phosphates
- Spectrometry, Mass, Electrospray Ionization