MAFP

Kinase experiment:

MAFP is dissolved and diluted in DMSO. To investigate the reversibility of iPLA 2 inhibition by MAFP, the P388D1 iPLA 2 is first concentrated approximately 10-fold using a Centricon-10 concentrator from Amicon. The concentrated iPLA 2 (20 μL) is then preincubated with either 80 μM MAFP in DMSO or DMSO alone (2 μL) for 5 min at 40°C. A 2 μL aliquot is removed and subsequently diluted 1500-fold into 3 mL of assay mixture containing 100 μM DPPC (200000 cpm per 50 μL assay mixture), 400 μM Triton X-100, 100 mM Hepes (pH 7.5), 5 mM EDTA, 1 mM DTT and 0.8 mM ATP. At the indicated time points, a 50 μL aliquot is removed and the remaining enzyme activity is quantified[1].

Cell experiment:

Inhibition of anandamide amidase in cell culture is measured using approximately 1x106 Nl8TG2 intact neuroblastoma cells. Experimental cells are preincubated for 20 min in 1.5 mL medium, consisting of Fl2/DMEM with penicillin, streptomycin, gentamicin, 10% bovine calf serum, plus MAFP (1, 5, 10, 20 nM). Control cells contained no inhibitor. Arachidonoyl is then added and the incubation continued for I hr. The amount of [3H]anandamide in the cells is quantified by liquid scintillation counting of the silica scraped from the appropriate areas of the TLC plate identified by exposure to X-ray film[2].

References:

[1]. Lio YC, et al. Irreversible inhibition of Ca(2+)-independent phospholipase A2 by methyl arachidonyl fluorophosphonate. Biochim Biophys Acta. 1996 Jul 12;1302(1):55-60.
[2]. Deutsch DG, et al. Methyl arachidonyl fluorophosphonate: a potent irreversible inhibitor of anandamide amidase. Biochem Pharmacol. 1997 Feb 7;53(3):255-60.