Department of Chemistry, Faculty of Science, Nara Women's University, Kitauoyanishi-machi, Nara, 630-8506, Japan.
Chembiochem. 2018 Oct 18;19(20):2156-2159. doi: 10.1002/cbic.201800331. Epub 2018 Sep 26.
Cytochrome P450 enzymes are heme-containing monooxygenases that exhibit potential as biocatalysts for practical applications. The Escherichia coli expression system is frequently used for biocatalyst production; however, heterologous production of hemeproteins in their holo form is difficult due to insufficient heme synthesis by the host. In this study, 5-aminolevulinic acid synthase (ALAS) from Rhodobacter capsulatus is used to accelerate intracellular heme biosynthesis in E. coli; this demonstrates that coexpression of the ALAS gene (ALAS) improves the heterologous production of cytochrome P450, CYP119, from Sulfolobus acidocaldarius. Coexpression of ALAS increased the amount of heterologous CYP119 isolated and the ratio of its holo form. The ratio of holo-CYP119 resulting from the coexpression of ALAS in E. coli was 99 %, whereas that from cells expressing CYP119 exclusively was 66 %. Coexpression of ALAS is a promising alternative for the efficient heterologous production of hemeproteins by using E. coli.
细胞色素 P450 酶是含有血红素的单加氧酶，具有作为实用生物催化剂的潜力。大肠杆菌表达系统常用于生物催化剂的生产；然而，由于宿主中血红素合成不足，血红蛋白的异源生产以全酶形式存在困难。在本研究中，来自荚膜红细菌的 5-氨基酮戊酸合酶（ALAS）用于加速大肠杆菌中细胞内血红素的生物合成；这表明共表达 ALAS 基因（ALAS）可提高来自嗜酸热硫化叶菌的细胞色素 P450、CYP119 的异源生产。ALAS 的共表达增加了分离出的异源 CYP119 的量及其全酶形式的比例。来自大肠杆菌中 ALAS 共表达的全酶形式的 holo-CYP119 比例为 99%，而仅表达 CYP119 的细胞中的比例为 66%。ALAS 的共表达是使用大肠杆菌高效异源生产血红蛋白的一种很有前途的替代方法。
