McMahon K K, Piron K J, Ha V T, Fullerton A T
Department of Pharmacology, Texas Tech University Health Sciences Center, Lubbock 79430.
Biochem J. 1993 Aug 1;293 ( Pt 3)(Pt 3):789-93. doi: 10.1042/bj2930789.
ADP-ribosylation of protein in heart membrane preparations has been shown to be present in adult tissue but absent from early neonate tissue [Piron and McMahon (1990) Biochem. J. 270, 591-597]. To further this observation, the cardiac membrane-bound form of arginine-specific mono-ADP-ribosyltransferase (EC 2.4.2.31) has been characterized. Apparent Km values of 330 and 470 microM were found in heart membrane preparations from rat and quail respectively. The Vmax. value depended greatly on the species of animal studied, and was 1.1 and 48 nmol/min per mg in rat and quail preparations respectively. The specific activity of the enzyme was lowest in pig, intermediate in rat, dog and rabbit, and highest in mouse and quail cardiac membranes. In the rat, the ADP-ribosylation of protein and enzyme activity were very low in heart preparations from 1-15-day-old animals. Thereafter the ADP-ribosylation and enzyme activity increased gradually to adulthood. Bacillus cereus phosphatidylinositol-specific phospholipase C, known to hydrolyse glycosylphosphatidylinositol anchors of proteins, released the mono-ADP-ribosyltransferase from membrane preparations of both rat and quail in a dose-dependent, Zn(2+)-inhibited manner. Thus it appears that a membrane-bound form of arginine-specific mono-ADP-ribosyltransferase is present in heart membranes from a variety of species and is not species-specific. The activity of this ADP-ribosyltransferase appears to be developmentally regulated and to be bound to the cardiac membranes by a glycosylphosphatidylinositol anchor.
已证明，心脏膜制剂中的蛋白质ADP核糖基化存在于成年组织中，但在新生儿早期组织中不存在[皮龙和麦克马洪（1990年），《生物化学杂志》270卷，591 - 597页]。为了进一步研究这一观察结果，对精氨酸特异性单ADP核糖基转移酶（EC 2.4.2.31）的心脏膜结合形式进行了表征。在大鼠和鹌鹑的心脏膜制剂中，分别发现表观Km值为330和470微摩尔。最大反应速度（Vmax）值在很大程度上取决于所研究的动物种类，在大鼠和鹌鹑制剂中分别为每毫克1.1和48纳摩尔/分钟。该酶的比活性在猪中最低，在大鼠、狗和兔中居中，在小鼠和鹌鹑心脏膜中最高。在大鼠中，1 - 15日龄动物心脏制剂中的蛋白质ADP核糖基化和酶活性非常低。此后，ADP核糖基化和酶活性逐渐增加至成年水平。已知蜡样芽孢杆菌磷脂酰肌醇特异性磷脂酶C可水解蛋白质的糖基磷脂酰肌醇锚定物，它以剂量依赖性、锌（2 +）抑制的方式从大鼠和鹌鹑的膜制剂中释放单ADP核糖基转移酶。因此，似乎精氨酸特异性单ADP核糖基转移酶的膜结合形式存在于多种物种的心脏膜中，且不是物种特异性的。这种ADP核糖基转移酶的活性似乎受发育调控，并通过糖基磷脂酰肌醇锚定物与心脏膜结合。
