Inhibition of diacylglycerol kinase by the antitumor agent calphostin C

摘要: Calphostin C is an anti-tumor agent that binds to the regulatory domain of protein kinase and inhibits binding phorbol dibutyrate. Recent studies suggest there may be structural similarities between (PKC) diacylglycerol (DGK). Both enzymes bind phosphatidylserine, sequencing 80 kDa shows it contains zinc finger-like sequences, similar those occurring in PKC. Similarities some enzymatic properties PKC DGK led us examine whether regulatory-site inhibitors also might inhibit DGK. For these studies, membrane-bound was partially purified from porcine testis membranes. inhibited with IC50 micromolar range. The inhibition by calphostin competitive respect not affected presence or absence phosphatidylserine. Other were without effect, exception Adriamycin, which at millimolar concentrations. Staurosporine, catalytic C, did results are functional substrate site C.