人类egasyn结合beta-glucuronidase但是egasyn的酯酶的活性位点和C末端beta-glucuronidase参与他们的互动。
文章的细节
-
引用
复制到剪贴板 -
伊斯兰教先生,他,沙GN Tomatsu年代,狡猾的WS
人类egasyn结合beta-glucuronidase但是egasyn的酯酶的活性位点和C末端beta-glucuronidase参与他们的互动。
拱生物化学Biophys。1999年12月1日,372 (1):53 - 61。
- PubMed ID
-
10562416 (在PubMed]
- 文摘
-
溶酶体beta-glucuronidase显示了一个双重定位在小鼠肝脏,很大一部分被保留在内质网(ER)与一个叫做egasyn ER-resident羧基酯酶的交互。这种交互的鼠标egasyn (mEg)与小鼠beta-glucuronidase (mGUSB)需要绑定的c端8残留mGUSB的羧酸酯酶活性部位的梅格。我们分离重组人类同系物的鼠标egasyn cDNA,发现它也结合人类beta-glucuronidase (hGUSB)。然而,绑定似乎没有涉及人类的活性部位egasyn (hEg)和不涉及hGUSB的c端18种氨基酸。全长cDNA编码hEg隔绝人类肝cDNA图书馆使用全身梅格cDNA探针。1941 - bp cDNA不同,只有少数基地从两个之前报道的互补对人类肝脏羧酸酯酶,允许反羧酸酯酶抗血清人类egasyn用于免疫沉淀反应。的cDNA表达bis-p-nitrophenyl磷酸(BPNP)制约因为细胞酯酶活动。因为细胞中表达时,局部ER。全身的细胞内hEg coimmunoprecipitated hGUSB和截断hGUSB失踪c端18-amino-acid残渣提取时因为细胞表达蛋白质都是对待anti-hGUSB抗体。它没有coimmunoprecipitate提取的mGUSB coexpressing因为细胞。 Unlike mEg, hEg was not released from the hEg-GUSB complex with BPNP. Thus, hEg resembles mEg in that it binds hGUSB. However, it differs from mEg in that (i) it does not appear to use the esterase active site for binding since treatment with BPNP did not release hEg from hGUSB and (ii) it does not use the C terminus of GUSB for binding, since a C-terminal truncated hGUSB (the C-terminal 18 amino acids are removed) bound as well as nontruncated hGUSB. Evidence is presented that an internal segment of 51 amino acids between 228 and 279 residues contributes to binding of hGUSB by hEg.