Lougovoi C P, Kyriakidis D A
Faculty of Chemistry, Aristotelian University of Thessaloniki, Greece.
Biochim Biophys Acta. 1989 Jun 13;996(1-2):70-5. doi: 10.1016/0167-4838(89)90096-4.
A protein kinase and an acidic phosphoprotein phosphatase were purified from Tetrahymena pyriformis which phosphorylate and dephosphorylate the purified ornithine decarboxylase (ODC) of this microorganism. The protein kinase and the phosphoprotein phosphatase are copurified with ODC and can be separated in three distinct peaks only by a hydrophobic column of phenyl-Sepharose. The purified kinase is not dependent on cAMP, requires Mg2+ for its catalytic activity and has a molecule mass of 45 kDa. Incubation of [32P]ODC with the purified phosphoprotein phosphatase results in a complete loss of 32P and its catalytic activity. Phosphorylation of the inactive phosphatase-treated ODC by endogenous kinase or rat liver casein kinase-2 results in 100 or 40% reactivation of the initial untreated ODC activity, respectively.
从梨形四膜虫中纯化出一种蛋白激酶和一种酸性磷酸蛋白磷酸酶，它们可使这种微生物纯化的鸟氨酸脱羧酶（ODC）发生磷酸化和去磷酸化反应。蛋白激酶和磷酸蛋白磷酸酶与ODC共纯化，并且仅通过苯基琼脂糖疏水柱才能分离成三个不同的峰。纯化的激酶不依赖于环磷酸腺苷（cAMP），其催化活性需要Mg2+，分子量为45千道尔顿。[32P]ODC与纯化的磷酸蛋白磷酸酶一起温育会导致32P及其催化活性完全丧失。用内源性激酶或大鼠肝脏酪蛋白激酶-2对无活性的经磷酸酶处理的ODC进行磷酸化，分别会使初始未处理的ODC活性重新激活100%或40%。
