Schwarz Paul N, Roller Luisa, Kulik Andreas, Wohlleben Wolfgang, Stegmann Evi
Microbiology/Biotechnology, Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), Eberhard Karls University Tübingen, Tübingen, Germany.
German Centre for Infection Research (DZIF), Partner Site Tübingen, Tübingen, Germany.
Synth Syst Biotechnol. 2018 Jan 12;3(1):56-63. doi: 10.1016/j.synbio.2017.12.005. eCollection 2018 Mar.
The isoprenoid brasilicardin A is a promising immunosuppressant compound with a unique mode of action, high potency and reduced toxicity compared to today's standard drugs. However, production of brasilicardin has been hampered since the producer strain IFM0406 synthesizes brasilicardin in only low amounts and is a biosafety level 2 organism. Previously, we were able to heterologously express the brasilicardin gene cluster in the nocardioform actinomycete Four brasilicardin congeners, intermediates of the BraA biosynthesis, were produced. Since chemical synthesis of the brasilicardin core structure has remained elusive we intended to produce high amounts of the brasilicardin backbone for semi synthesis and derivatization. Therefore, we used a metabolic engineering approach to increase heterologous production of brasilicardin in . Simultaneous heterologous expression of genes encoding the MVA pathway and expression of diterpenoid specific prenyltransferases were used to increase the provision of the isoprenoid precursor isopentenyl diphosphate (IPP) and to channel the precursor into the direction of diterpenoid biosynthesis. Both approaches contributed to an elevated heterologous production of the brasilicardin backbone, which can now be used as a starting point for semi synthesis of new brasilicardin congeners with better properties.
类异戊二烯巴西卡定A是一种很有前景的免疫抑制化合物，其作用模式独特，效力高，与当今的标准药物相比毒性更低。然而，由于生产菌株IFM0406仅能少量合成巴西卡定，且属于生物安全2级生物体，巴西卡定的生产受到了阻碍。此前，我们能够在诺卡氏放线菌中异源表达巴西卡定基因簇。产生了四种巴西卡定同系物，即BraA生物合成的中间体。由于巴西卡定核心结构的化学合成一直难以实现，我们打算大量生产巴西卡定主链用于半合成和衍生化。因此，我们采用代谢工程方法来提高巴西卡定在……中的异源产量。同时异源表达编码MVA途径的基因和二萜特异性异戊烯基转移酶的表达，以增加类异戊二烯前体异戊烯基二磷酸（IPP）的供应，并将前体引导至二萜生物合成方向。这两种方法都有助于提高巴西卡定主链的异源产量，现在它可以作为半合成具有更好特性的新巴西卡定同系物的起点。
