Chen C J, Huang H S, Lee Y T, Yang C Y, Chang W C
Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan, Taiwan 70101, Republic of China.
Biochem J. 1997 Oct 1;327 ( Pt 1)(Pt 1):193-8. doi: 10.1042/bj3270193.
A lipoxygenase inhibitor in the cytosolic fraction of human epidermoid carcinoma A431 cells was characterized and purified. The cytosolic inhibitor lost the inhibitory activity upon heating at 75 degrees C for 15 min or pretreating with 1 mg/ml trypsin at 37 degrees C for 60 min. Cytosol, after dialysis, lost the inhibitory activity but its inhibitory activity recovered when 1 mM GSH was added to the dialysate. The inhibitory activity of cytosol was also abolished by treatment either with 1 mM iodoacetate at 4 degrees C for 1 h or with 0.5 mM H2O2. The pI of the inhibitor was approx. 7.0. In addition to 12-lipoxygenase, the inhibitor inhibited the activities of 5-lipoxygenase and fatty acid cyclo-oxygenase in a cell-free system. The inhibitor was purified by a series of column chromatographies using CM Sephadex C-50, Sephadex G-100 SF and Mono P columns. A major 22 kDa protein was obtained that was distinct from selenium-dependent glutathione peroxidase.
对人表皮样癌A431细胞胞质部分的一种脂氧合酶抑制剂进行了特性鉴定和纯化。该胞质抑制剂在75℃加热15分钟或在37℃用1mg/ml胰蛋白酶预处理60分钟后失去抑制活性。透析后的胞质溶胶失去抑制活性，但当向透析液中加入1mM谷胱甘肽时其抑制活性恢复。胞质溶胶的抑制活性也可通过在4℃用1mM碘乙酸处理1小时或用0.5mM过氧化氢处理而被消除。该抑制剂的pI约为7.0。除了12-脂氧合酶外，该抑制剂在无细胞体系中还抑制5-脂氧合酶和脂肪酸环氧化酶的活性。通过使用CM Sephadex C-50、Sephadex G-100 SF和Mono P柱的一系列柱色谱法对该抑制剂进行了纯化。获得了一种主要的22kDa蛋白质，它与硒依赖性谷胱甘肽过氧化物酶不同。
