Sobek H, Görisch H
Intitut für Mikrobiologie der Universität Hohenheim, Stuttgart, Federal Republic of Germany.
Biochem J. 1988 Mar 1;250(2):453-8. doi: 10.1042/bj2500453.
A heat-stable esterase has been purified 1080-fold to electrophoretic homogeneity from Sulfolobus acidocaldarius, a thermoacidophilic archaebacterium; 20% of the starting activity is recovered. The purified enzyme shows a specific activity of 158 units/mg, based on the hydrolysis of p-nitrophenyl acetate. The esterase hydrolyses short-chain p-nitrophenyl esters, aliphatic esters and triacylglycerols. It is strongly inhibited by paraoxon and phenylmethanesulphonyl fluoride, but only weakly by eserine. From sedimentation-equilibrium data and molecular sieving in polyacrylamide gels, the Mr of the esterase is estimated to be 117000-128000. SDS/polyacrylamide-gel electrophoresis reveals a single band of protein, of Mr 32000. The purified esterase crystallizes in the presence of poly(ethylene glycol) in short rods. The enzyme is inactivated only on prolonged storage at temperature above 90 degrees C.
已从嗜热嗜酸古细菌嗜酸热硫化叶菌中纯化出一种热稳定酯酶，纯化倍数达1080倍，达到电泳纯；回收了起始活性的20%。基于对硝基苯乙酸酯的水解，纯化后的酶比活性为158单位/毫克。该酯酶可水解短链对硝基苯酯、脂肪族酯和三酰甘油。它受到对氧磷和苯甲基磺酰氟的强烈抑制，但仅受到毒扁豆碱的微弱抑制。根据沉降平衡数据和聚丙烯酰胺凝胶中的分子筛分析，该酯酶的相对分子质量估计为117000 - 128000。SDS/聚丙烯酰胺凝胶电泳显示出一条相对分子质量为32000的单一蛋白条带。纯化后的酯酶在聚乙二醇存在下结晶成短棒状。该酶仅在90℃以上温度长期保存时才会失活。
