Cheng N, Sahyoun N
Wellcome Research Laboratories, Burroughs Wellcome Co., Research Triangle Park, North Carolina 27709.
J Biol Chem. 1990 Feb 15;265(5):2417-20.
Neuronal glycoproteins derived from growth cones are enriched in protein tyrosine kinase activity. In contrast, glycoproteins obtained from mature synaptosomes are relatively lacking in this activity. At least three types of protein tyrosine kinases were detected in association with growth cone glycoproteins: 1) a Mn2(+)-dependent activity which phosphorylates several endogenous substrates; 2) a Mn2+/Mg2(+)-dependent activity which phosphorylates synthetic substrate and is stimulated by acidic brain extracts; and 3) protein tyrosine kinases corresponding to the insulin and insulin-like growth factor I receptors. These enzymes may be particularly important during earlier stages of neuronal maturation.
源自生长锥的神经元糖蛋白富含蛋白酪氨酸激酶活性。相比之下，从成熟突触小体获得的糖蛋白在这种活性方面相对缺乏。与生长锥糖蛋白相关联检测到至少三种类型的蛋白酪氨酸激酶：1）一种依赖Mn2+的活性，可磷酸化几种内源性底物；2）一种依赖Mn2+/Mg2+的活性，可磷酸化合成底物并受酸性脑提取物刺激；3）与胰岛素和胰岛素样生长因子I受体相对应的蛋白酪氨酸激酶。这些酶在神经元成熟的早期阶段可能特别重要。
