参与多胺反转化的哺乳动物多胺氧化酶的基因组鉴定和生化特性。
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武契奇，梁P，狄格尔曼P，克雷默DL，波特CW
参与多胺反转化的哺乳动物多胺氧化酶的基因组鉴定和生化特性。
Biochem J. 2003 Feb 15;370(Pt 1):19-28。
- PubMed ID
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12477380 (PubMed视图］
- 摘要
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在多胺反转化途径中，精胺和亚精胺首先被亚精胺/精胺N1 -乙酰转移酶(SSAT)乙酰化，然后被多胺氧化酶(PAO)氧化，分别生成亚精胺和腐胺。尽管PAO在20多年前首次被纯化，但这种蛋白质尚未与基因组序列联系起来。在本研究中，我们应用BLAST搜索策略来识别位于人类染色体10和小鼠染色体7上必威国际app的新的氧化酶序列。从人脑和小鼠乳腺肿瘤中推导出同源的哺乳动物cdna，编码约为。55 kDa具有82%的序列一致性。当任何一种cDNA瞬时转染到HEK-293细胞时，细胞内精胺池约减少。30%，而亚精胺增加了2-4倍。人PAO cdna转染的HEK-293细胞的裂解物，而不是载体转染的细胞，迅速将n1 -乙酰精胺氧化为亚精胺。底物特异性测定显示N1-乙酰亚精胺= N1-乙酰亚精胺> N1, n12 -二乙酰亚精胺>>精胺;亚精胺没有作用。 This ranking is identical to that reported for purified PAO and distinctly different from the recently identified spermine oxidase (SMO), which prefers spermine over N1-acetylspermine. Monoethyl- and diethylspermine analogues also served as substrates for PAO, and were internally cleaved adjacent to a secondary amine. We deduce that the present oxidase sequences are those of the FAD-dependent PAO involved in the polyamine back-conversion pathway. In Northern blot analysis, PAO mRNA was much less abundant in HEK-293 cells than SMO or SSAT mRNA, and all three were differentially induced in a similar manner by selected polyamine analogues. The identification of PAO sequences, together with the recently identified SMO sequences, provides new opportunities for understanding the dynamics of polyamine homoeostasis and for interpreting metabolic and cellular responses to clinically-relevant polyamine analogues and inhibitors.