Metabolism of 1alpha-hydroxyvitamin D3 by cytochrome P450scc to biologically active 1alpha,20-dihydroxyvitamin D3.
Metabolism of 1alpha-hydroxyvitamin D3 by cytochrome P450scc to biologically active 1alpha,20-dihydroxyvitamin D3.
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DOI：
10.1016/j.jsbmb.2008.10.005
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发表时间：
2008-12
影响因子：
4.1
通讯作者：
Slominski, Andrzej
中科院分区：
文献类型：
--
作者：
Tuckey, Robert C.;Janjetovic, Zorica;Li, Wei;Nguyen, Minh N.;Zmijewski, Michal A.;Zjawiony, Jordan;Slominski, Andrzej
细胞色素P450scc(Cyp11a1)主要代谢维生素D3为20-羟基维生素D3，随后产生二羟基和三羟基衍生物。本研究的目的是确定细胞色素P450scc是否能代谢1-α-羟基维生素D3，以及产物是否具有生物活性。P450scc代谢1-α-羟基维生素D3的主要产物经质谱和核磁共振鉴定为1-α，20-二羟基维生素D3。次要代谢物的质谱分析显示，产生了另一种二羟基维生素D3衍生物，两种三羟基代谢物由1-α，20-二羟基维生素D3和四羟基维生素D3衍生物生成。将P450scc掺入磷脂囊泡，测得1α-羟基维生素D3的Km值为1.4m ol底物/m ol磷脂，是维生素D3的一半。Kcat为3.0mol/min/molP450scc，比维生素D3低6倍。1α，20-二羟基维生素D3以时间和剂量依赖的方式抑制培养的人表皮HaCaT角质形成细胞的DNA合成，其效力与1α，25-二羟基维生素D3相似。1α，20-二羟基维生素D3(10μM)可促进角质形成细胞的细胞色素P24基因表达，但其作用强度远低于报道的1α，25-二羟基维生素D3。我们的结论是，维生素D3中1-羟基的存在不会改变P450scc的主要羟化部位，而维生素D3的主要羟化部位在C20。主要产物1，α，20-二羟基维生素D3，对角质形成细胞具有生物活性，因此可能有药用价值。
Cytochrome P450scc (CYP11A1) metabolizes vitamin D3 to 20-hydroxyvitamin D3 as the major product, with subsequent production of dihydroxy and trihydroxy derivatives. The aim of this study was to determine whether cytochrome P450scc could metabolize 1α-hydroxyvitamin D3 and whether products were biologically active. The major product of 1α-hydroxyvitamin D3 metabolism by P450scc was identified by mass spectrometry and NMR as 1α,20-dihydroxyvitamin D3. Mass spectrometry of minor metabolites revealed the production of another dihydroxyvitamin D3 derivative, two trihydroxy-metabolites made via 1α,20-dihydroxyvitamin D3 and a tetrahydroxyvitamin D3 derivative. The Km for 1α-hydroxyvitamin D3 determined for P450scc incorporated into phospholipid vesicles was 1.4 mol substrate/mol phospholipid, half that observed for vitamin D3. The kcat was 3.0 mol/min/mol P450scc, 6-fold lower than that for vitamin D3. 1α,20-Dihydroxyvitamin D3 inhibited DNA synthesis by human epidermal HaCaT keratinocytes propagated in culture, in a time- and dose-dependent fashion, with a potency similar to that of 1α,25-dihydroxyvitamin D3. 1α,20-Dihydroxyvitamin D3 (10 μM) enhanced CYP24 mRNA levels in HaCaT keratinocytes but the potency was much lower than that reported for 1α,25-dihydroxyvitamin D3. We conclude that the presence of the 1-hydroxyl group in vitamin D3 does not alter the major site of hydroxylation by P450scc which, as for vitamin D3, is at C20. The major product, 1α,20-dihydroxyvitamin D3, displays biological activity on keratinocytes and therefore might be useful pharmacologically.
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影响因子：
5.6
作者：
Slominski, A;Pisarchik, A;Wortsman, J
通讯作者：
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影响因子：
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影响因子：
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作者：
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