Buneeva O A, Medvedeva M V, Medvedev A E
Biomed Khim. 2007 Sep-Oct;53(5):603-8.
Incubation of rat brain mitochondria with ubiquitin and ATP followed by subsequent mitochondria sedimentation was accompanied by reduction of ubiquitin content in the supernatant. This decrease was more pronounced in the presence of ATP-regenerating system in the incubation medium (creatine phosphate/creatine phosphokinase). This ubiquitin incorporation into brain mitochondria observed only in the presence of ATP in the incubation medium increased sensitivity of monoamine oxidases (MAO) A and B to proteolytic inactivation by trypsin and papain, respectively. (Ubiquitin did not influence sensitivity of MAO B to trypsin and MAO A to papain). The data obtained suggest that ubiquitin incorporation into rat brain mitochondria increases susceptibility of MAOs to certain exogenous proteases, however, it remains unclear whether these changes stem from direct MAO-ubiquitin conjugation or reflect alterations in the membrane environment of these enzymes.
将大鼠脑线粒体与泛素和ATP一起孵育，随后进行线粒体沉降，结果上清液中的泛素含量降低。在孵育培养基中存在ATP再生系统（磷酸肌酸/肌酸磷酸激酶）的情况下，这种降低更为明显。仅在孵育培养基中存在ATP时观察到的这种泛素掺入脑线粒体的现象，分别增加了单胺氧化酶（MAO）A和B对胰蛋白酶和木瓜蛋白酶蛋白水解失活的敏感性。（泛素不影响MAO B对胰蛋白酶的敏感性以及MAO A对木瓜蛋白酶的敏感性）。所获得的数据表明，泛素掺入大鼠脑线粒体增加了MAO对某些外源性蛋白酶的敏感性，然而，目前尚不清楚这些变化是源于MAO与泛素的直接结合还是反映了这些酶膜环境的改变。
