Uings I J, Spacey G D, Bonser R W
Cell Signalling Group, Biology Division, Wellcome Research Laboratories, Beckenham, Kent, UK.
Cell Signal. 1999 Feb;11(2):95-100. doi: 10.1016/s0898-6568(98)00039-4.
The cytoplasmic domain of the platelet-derived growth factor (PDGF) beta-receptor was expressed in insect cells by using a baculovirus system. The resulting protein was a constitutively active tyrosine kinase that could phosphorylate both protein and peptide substrates. A recently identified potent and selective inhibitor of intact PDGF receptor autophosphorylation, 3744W, inhibited the autophosphorylation of the cytoplasmic domain both in vitro (IC50 1.8+/-0.12 microM) and within intact insect cells (IC50 2.0 microM). However, under identical assay conditions, 3744W did not inhibit the phosphorylation of the synthetic polymeric peptide poly(Glu4Tyr1) even at concentrations as high as 100 microM. These results suggest that, although 3744W inhibits PDGF receptor autophosphorylation directly, it can discriminate between phosphate acceptor substrates.
利用杆状病毒系统在昆虫细胞中表达血小板衍生生长因子（PDGF）β受体的胞质结构域。产生的蛋白质是一种组成型活性酪氨酸激酶，能够磷酸化蛋白质和肽底物。最近鉴定出的一种针对完整PDGF受体自磷酸化的强效选择性抑制剂3744W，在体外（IC50为1.8±0.12微摩尔）和完整昆虫细胞内（IC50为2.0微摩尔）均能抑制胞质结构域的自磷酸化。然而，在相同的检测条件下，即使浓度高达100微摩尔，3744W也不抑制合成聚合物肽聚（Glu4Tyr1）的磷酸化。这些结果表明，尽管3744W直接抑制PDGF受体自磷酸化，但它能够区分磷酸受体底物。
