Department of Biochemistry, Saarland University, 66123 Saarbrücken, Germany.
Appl Microbiol Biotechnol. 2012 Jul;95(1):123-33. doi: 10.1007/s00253-011-3727-z. Epub 2012 Jan 6.
Many terpenes and terpenoid compounds are known as bioactive substances with desirable fragrance and medicinal activities. Modification of such compounds to yield new derivatives with desired properties is particularly attractive. Cytochrome P450 monooxygenases are potential enzymes for these reactions due to their capability of performing different reactions on a variety of substrates. We report here the characterization of CYP264B1 from Sorangium cellulosum So ce56 as a novel sesquiterpene hydroxylase. CYP264B1 was able to convert various sesquiterpenes including nootkatone and norisoprenoids (α-ionone and β-ionone). Nootkatone, an important grapefruit aromatic sesquiterpenoid, was hydroxylated mainly at position C-13. The product has been shown to have the highest antiproliferative activity compared with other nootkatone derivatives. In addition, CYP264B1 was found to hydroxylate α- and β-ionone, important aroma compounds of floral scents, regioselectively at position C-3. The products, 3-hydroxy-β-ionone and 13-hydroxy-nootkatone, were confirmed by (1)H and (13)C NMR. The kinetics of the product formation was analyzed by high-performance liquid chromatography, and the K ( m ) and k (cat) values were calculated. The results of docking α-/β-ionone and nootkatone into a homology model of CYP264B1 revealed insights into the structural basis of these selective hydroxylations.
许多萜类化合物和类萜化合物被认为是具有理想香气和药用活性的生物活性物质。修饰这些化合物以产生具有所需性质的新衍生物特别有吸引力。细胞色素 P450 单加氧酶由于能够对各种底物进行不同的反应，因此是这些反应的潜在酶。我们在这里报道了来自 Sorangium cellulosum So ce56 的 CYP264B1 作为一种新型倍半萜烯羟化酶的特性。CYP264B1 能够转化各种倍半萜烯，包括诺卡酮和异戊二烯（α-紫罗兰酮和β-紫罗兰酮）。诺卡酮是一种重要的葡萄柚芳香倍半萜烯，主要在 C-13 位羟基化。与其他诺卡酮衍生物相比，该产物显示出最高的抗增殖活性。此外，CYP264B1 被发现能够选择性地在 C-3 位羟基化α-和β-紫罗兰酮，这是花香的重要香气化合物。通过（1）H 和（13）C NMR 证实了产物为 3-羟基-β-紫罗兰酮和 13-羟基-诺卡酮。通过高效液相色谱分析了产物形成的动力学，并计算了 K（m）和 k（cat）值。将α-/β-紫罗兰酮和诺卡酮对接入 CYP264B1 的同源模型的结果揭示了这些选择性羟基化的结构基础。
