Bs. Szwergold et al., CHARACTERIZATION OF A PHOSPHONIUM ANALOG OF CHOLINE AS A PROBE IN P-31 NMR-STUDIES OF PHOSPHOLIPID-METABOLISM, NMR in biomedicine, 7(3), 1994, pp. 121-127
Citations number
42
Categorie Soggetti
Spectroscopy,"Radiology,Nuclear Medicine & Medical Imaging",Biophysics,"Medical Laboratory Technology
Tumors and transformed cells have been shown by P-31 NMR to contain el
evated concentrations of two phosphomonoesters, phosphorylcholine and
phosphorylethanolamine, involved in phospholipid metabolism. In order
to understand the biochemical basis for these phenomena new methods ar
e needed to allow for analysis of the relevant metabolic pathways in i
ntact cells. One such promising tool may be phosphonium-choline, a P-3
1 NMR-visible analog of choline in which the trimethyl-ammonium group
of choline has been replaced with a trimethyl-phosphonium moiety. As s
hown previously [Sim et al. Biochem. J. 154, 303 (1976)], this compoun
d is non-toxic and readily metabolized by cultured cells into phosphol
ipids. In this paper we describe in greater detail some of the chemica
l and NMR spectroscopic properties of this material. Most significantl
y we show here that the chemical shift of phosphonium-choline is sensi
tive to the phosphorylation state of the analog and that the phosphoni
um nucleus is NMR-visible even after its incorporation into phospholip
id. The unique properties of this analog should make it possible to us
e high-field P-31 NMR to follow the flux of phosphonium-choline throug
h the Kennedy pathway in intact perfused cells cultures.