Accumulation of mitochondrial P450MT2, NH2-terminal truncated cytochrome P4501A1 in rat brain during chronic treatment with β-naphthoflavone -: A role in the metabolism of neuroactive drugs
Accumulation of mitochondrial P450MT2, NH2-terminal truncated cytochrome P4501A1 in rat brain during chronic treatment with β-naphthoflavone -: A role in the metabolism of neuroactive drugs
复制标题
DOI：
10.1074/jbc.m004431200
复制
发表时间：
2000-11-03
影响因子：
4.8
通讯作者：
Avadhani, NG
中科院分区：
文献类型：
--
作者：
Boopathi, E;Anandatheerthavarada, HK;Avadhani, NG
研究细胞色素P4501A1靶向大鼠脑线粒体的生化和分子特性，以确定先前描述的大鼠肝脏线粒体细胞色素P450MT2 （P450MT2）靶向机制的普遍性。在长期暴露于-萘黄酮（BNF）的大鼠脑和C6胶质瘤细胞中，P450MT2含量分别达到总细胞池的50%和95%。从bnf处理10天的大鼠脑中提取的P450MT2用疏水色谱纯化到85%以上的纯度，然后用肾上腺素还毒素亲和结合。纯化的脑P450MT2由两个不同的分子种类组成，其NH2末端与肝脏线粒体形式相同。这些结果证实了内源性蛋白酶加工位点的特异性。纯化后的P450MT2表现出对肾上腺素还原酶+肾上腺素还原酶电子供体系统的偏好，并表现出较高的红霉素n -去甲基化活性。bnf治疗10天的大鼠和纯化的P450MT2的脑有丝分裂体对许多神经活性药物（包括三环抗抑郁药、抗惊厥药和阿片类药物）表现出高的n -去甲基化活性。在BNF治疗第10天，这些神经活性药物的线粒体代谢约占总组织活性的85%。这些结果为P450MT2在慢性暴露个体中调节不同神经活性药物药理学效力的作用提供了新的见解。
The biochemical and molecular characteristics of cytochrome P4501A1 targeted to rat brain mitochondria was studied to determine the generality of the targeting mechanism previously described for mitochondrial cytochrome P450MT2 (P450MT2) from rat liver. In rat brain and C6 glioma cells chronically exposed to beta -naphoflavone (BNF), P450MT2 content reached 50 and 95% of the total cellular pool, respectively. P450MT2 from 10 days of BNF-treated rat brain was purified to over 85% purity using hydrophobic chromatography followed by adrenodoxin affinity binding. Purified brain P450MT2 consisted of two distinct molecular species with NH2 termini identical to liver mitochondrial forms. These results confirm the specificity of endoprotease-processing sites. The purified P450MT2 showed a preference for adrenodoxin + adrenodoxin reductase electron donor system and exhibited high erythromycin N-demethylation activity. Brain mitoplasts from 10-day BNF-treated rats and also purified P450MT2 exhibited high N-demethylation activities for a number of neuroactive drugs, including trycyclic anti-depressants, anti-convulsants, and opiates. At 10 days of BNF treatment, the mitochondrial metabolism of these neuroactive drugs represented about 85% of the total tissue activity. These results provide new insights on the role of P450MT2 in modulating the pharmacological potencies of different neuroactive drugs in chronically exposed individuals.