Investigation of subcellular acidic compartments using alpha-aminophosphonate (31)P nuclear magnetic
July 3rd, 2008 | by admin |Investigation of subcellular acidic compartments using alpha-aminophosphonate (31)P nuclear magnetic resonance probes.
The (31)P nuclear magnetic resonance (NMR) characteristics, toxicity, and cellular penetration of five linear or cyclic alpha-aminophosphonate highly sensitive pH probes were investigated in Dictyostelium discoideum cells and isolated rat hearts and were compared with three phosphonic acid derivatives. The line width broadening at pH approximately pK(a), which was satisfactorily modelized for all compounds, was significantly limited in biological milieu for the new markers, affording a four- to sixfold better accuracy in pH determination. Cellular uptake or washout of nontoxic concentrations (<15mM) of alpha-aminophosphonates occurred by rapid passive permeation, whereas standard probes required a much slower fluid-phase pinocytosis and transport processes that could ultimately lead to trapping. Using mild concentrations (<4mM) three alpha-aminophosphonates having 6<pK(a)<7 allowed an easy and simultaneous (31)P NMR determination of cytosolic, acidic, and extracellular compartments in anoxic-reoxygenated or starving D. discoideum.
Gosset G, Satre M, Blaive B, Clément JL, Martin JB, Culcasi M, Pietri S.
Groupe Sondes Moléculaires en Biologie–SREP, Laboratoire Chimie Provence–UMR 6264, Universités d’Aix-Marseille–CNRS, F-13397 Marseille Cedex 20, France.