Example 2
Protein kinase C assay. Recombinant PKC (1 ng of alpha or epsilon isofonn) was mixed with the BR-101 (UCP-LA) in the presence of 10 micromoiar histones, 5 mM CaCl2, 1.2 μg/μl phosphatidyl-L-serine, 0.18 μg/μl 1,2-dioctanoyl-sn-glycerol (DAG), 10 nM MgCL2, 20 nM HEPES (pH 7.4), 0.8 tnIVI EDTA, 4 mM EGTA, 4% glycerol, 8 μg/ml aprotinin, 8 μ/ml leupeptin, and 2 mM benzamidine. 0.5 micro Ci [y32P]ATP was added. The incubation mixture was incubated for 15 min at 37 degrees in a total volume of 10 microliters. The reaction was stopped by spotting the reaction mixtures on 1×2 cm strips of cellulose phosphate paper (Whatman P81) and immediately washing twice for 1 hr in 0.5% H3PO4. The cellulose phosphate strips were counted in a scintillation counter. In some experiments, phosphatidylserine, diacylglycerol, and/or calcium were removed.
DHA methyl ester was purchased from Cayman Chemical (Ann Arbor, Me.). PKC isozymes were from Calbiochem (San Diego, Calif.). Purified PKCε was purchased from Calbiochem.