Investigation of subcellular acidic compartments using alpha-aminophosphonate 31P nuclear magnetic resonance probes.
The 31P 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 (< 15 mM) 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 (< 4 mM) three alpha-aminophosphonates having 6 < pK(a) < 7 allowed an easy and simultaneous 31P NMR determination of cytosolic, acidic, and extracellular compartments in anoxic-reoxygenated or starving D. discoideum.
Gosset
Gaëlle
G
Groupe Sondes Moléculaires en Biologie, Laboratoire Chimie Provence-UMR 6264, Universités d'Aix-Marseille-CNRS, F-13397 Marseille Cedex 20, France.
Satre
Michel
M
Blaive
Bruno
B
Clément
Jean-Louis
JL
Martin
Jean-Baptiste
JB
Culcasi
Marcel
M
Pietri
Sylvia
S
D000588:Amines / Q000737:chemistry* / Q000493:pharmacokinetics / Q000633:toxicity; D000818:Animals; D002478:Cells, Cultured; D004023:Dictyostelium / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D006321:Heart / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D009206:Myocardium / Q000737:chemistry / Q000378:metabolism; D009457:Neuroglia / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D063065:Organophosphonates / Q000737:chemistry* / Q000493:pharmacokinetics / Q000633:toxicity; D010539:Permeability; D010759:Phosphorus Isotopes / Q000032:analysis; D051381:Rats; D013347:Subcellular Fractions / Q000737:chemistry / Q000378:metabolism
D000588:Amines; D063065:Organophosphonates; D010759:Phosphorus Isotopes