Protein capable of binding to the upstream gene of the CYP2B subfamily P450

在大鼠和豚鼠中，苯巴比妥诱导肝脏CYP2B P-450的程度有很大不同。为了回答这一差异，我们比较了两种动物CYP2B1基因89 -73 bp区（Barbie box）寡核苷酸探针蛋白的结合情况。当使用肝核提取物作为蛋白质部分时，所有来自苯巴比妥预处理大鼠的制剂都与芭比盒有很强的结合，但许多来自未处理大鼠的制剂只有较弱的活性。与此相反，苯巴比妥对豚鼠肝核提取物的结合作用不明显。因此，大鼠和豚鼠对苯巴比妥治疗对核蛋白-探针相互作用的反应有显著差异。由于这一差异与大鼠和豚鼠CYP2B P-450蛋白诱导性的差异有关，因此我们认为CYP2B P-450的表达和诱导与该基因的核- More r蛋白和芭比盒区相互作用有关。通过化学效应剂、加热和蛋白酶处理，观察探针与大鼠核蛋白结合的变化。结果表明：1)Ca2+和Mg2+有效地增强了其结合；2)血红素和Triton X-100增加结合，而非苯巴比妥和地塞米松增加结合；3)核蛋白耐热变性至60℃。C和蛋白酶的蛋白水解。另一方面，与豚鼠肝核提取物的结合未见前两种作用或作用程度有限。与大鼠蛋白相比，能够与探针结合的豚鼠蛋白对加热的稳定性较差，对蛋白酶的敏感性较高。比较了细胞质溶胶在大鼠和豚鼠身上结合芭比盒的能力，并报道了结果。通过检测其与DNA探针的结合活性，从肝核提取物中纯化出一种豚鼠蛋白（BBBP-GP）。最小分子量估计为27000。大鼠核蛋白也得到了纯化，但只是部分纯化。n端序列分析表明BBBP-GP是一种新蛋白。该蛋白与寡核苷酸探针相互作用，但移位带被拉伸。少

The extent in the induction of hepatic CYP2B P-450 with phenobarbital is greatly different in rats and guinea pigs. To answer this difference the binding of protein to the oligonucleotide probe of-89 to-73 bp region (Barbie box) of CYP2B1 gene was compared in both animal species. When the nuclear extracts of liver were used as the protein fraction, all preparations from phenobarbital-pretreated rats showed strong binding to the Barbie box, but many preparations from untreated rats had only weak activities. On the contrary, the binding with liver nuclear extracts of guinea pigs was not increased by phenobarbital treatment. Therefore, the response to phenobarbital treatment on the nuclear protein-probe interaction was markedly different in rats and guinea pigs. Since this difference correlated with the contrast of the inducibility between rat and guinea pig CYP2B P-450 protein, it was suggested that the expression and induction of the CYP2B P-450 is related with the interaction of nuclea … More r proteins and Barbie box region of the gene. Alteration of the binding between the probe and rat nuclear protein with chemical effectors, and by heating and protease treatments was also examined. The results showed that 1)Ca2+ and Mg2+ effectively increase the binding ; 2)hemin and Triton X-100 but not phenobarbital and dexamethasone increase the binding ; and 3)nuclear protein resists to the heat-denaturation until 60。C and to the proteolysis with proteases. On the other hand, the former two effects were not seen or the extents were limited in the binding with guinea pig liver nuclear extracts. The guinea pig protein capable of binding to the probe were less stable against heating and were much sensitive against proteases than rat protein. The ability of cytosol to bind Barbie box was compared in rats and guinea pigs, and the results are also reported. A guinea pig protein (BBBP-GP) was purified from liver nuclear extracts by monitoring its binding activity toward DNA probe to electrophoretically homogeneous. The minimum molecular weight was estimated to be 27,000. Rat nuclear protein was also purified though only partially. The analysis of the N-terminal sequence indicated that BBBP-GP is a new protein. This protein interacted with oligonucleotide probe, but the shifted band was stretched. Less