Purdy R E, Kolattukudy P E
Biochemistry. 1975 Jul;14(13):2832-40. doi: 10.1021/bi00684a007.
The properties of the homogeneous cutinase I, cutinase II, and the nonspecific esterase isolated from the extracellular fluid of cutin-grown Fusarium solani F. pisi (R.E. Purdy and P.E. Kolattukudy (1975), Biochemistry, preceding paper in this issue) were investigated. Using tritiated apple cutin as substrate, the two cutinases showed similar substrate concentration dependence, protein concentration dependence, time course profiles, and pH dependence profiles with optimum near 10.0. Using unlabeled cutin, the rate of dihydroxyhexadecanoic acid release from apple fruit cutin by cutinase I was determined to be 4.4 mumol per min per mg. The cutinases hydrolyzed methyl hexadecanoate, cyclohexyl hexadecanoate, and to a much lesser extent hexadecyl hexadecanoate but not 9-hexadecanoyloxyheptadecane, cholesteryl hexadecanoate, or hexadecyl cinnamate. The extent of hydrolysis of these model substrates by cutinase I was at least three times that by cutinase II. The nonspecific esterase hydrolyzed all of the above esters except hexadecyl cinnamate, and did so to a much greater extent than did the cutinases. None of the enzymes hydrolyzed alpha- or beta-glucosides of p-nitrophenol. p-Nitrophenyl esters of fatty acids from C2 through C18 were used as substrates and V's and Kms were determined...
对从角质生长的豌豆镰孢菌（R.E. Purdy和P.E. Kolattukudy（1975年），《生物化学》，本期前文）细胞外液中分离出的均一角质酶I、角质酶II和非特异性酯酶的性质进行了研究。以氚标记的苹果角质为底物，两种角质酶表现出相似的底物浓度依赖性、蛋白质浓度依赖性、时间进程曲线和pH依赖性曲线，最适pH接近10.0。使用未标记的角质，测定角质酶I从苹果果实角质中释放二羟基十六烷酸的速率为每分钟每毫克4.4微摩尔。角质酶能水解十六烷酸甲酯、环己基十六烷酸酯，对十六烷基十六烷酸酯的水解程度要小得多，但不能水解9-十六烷酰氧基十七烷、胆固醇十六烷酸酯或十六烷基肉桂酸酯。角质酶I对这些模型底物的水解程度至少是角质酶II的三倍。非特异性酯酶能水解上述除十六烷基肉桂酸酯以外的所有酯类，且水解程度比角质酶大得多。这些酶都不能水解对硝基苯酚的α-或β-糖苷。以C2至C18的脂肪酸对硝基苯酯为底物，测定了V和Km……
