Jacobsen J R, Keatinge-Clay A T, Cane D E, Khosla C
Department of Chemical Engineering, Stanford University, CA 94305-5025, USA.
Bioorg Med Chem. 1998 Aug;6(8):1171-7. doi: 10.1016/s0968-0896(98)00081-9.
A precursor-directed method for the biosynthesis of novel 6-deoxyerythronolide B derivatives has been extended to allow alteration of the functionality at C-12. We recently described a simple and practical method for harnessing the biosynthetic potential of the erythromycin pathway to generate novel molecules of natural product-like complexity by feeding designed synthetic molecules to an engineered mutant strain having an altered 6-deoxyerythronolide B synthase (DEBS). Our initial applications of this technique focused on alteration of the ethyl side chain of 6-dEB (C14-C15). We now report the extension of this approach to modification of the C-12 substituent. An appropriately designed substrate is shown to incorporate into 6-dEB biosynthesis, yielding a 6-dEB analogue bearing a 12-ethyl group. This 6-dEB analogue is a substrate for post-polyketide tailoring enzymes, and is converted into the corresponding analogue of erythromycin C. These results show that many of the downstream active sites are tolerant of this unnatural functionality and suggest that a wide variety of erythromycin derivatives should be accessible by this approach or by total biosynthesis via genetic engineering.
一种用于新型6-脱氧红霉内酯B衍生物生物合成的前体导向方法已得到扩展，以允许改变C-12位的官能团。我们最近描述了一种简单实用的方法，即通过向具有改变的6-脱氧红霉内酯B合酶（DEBS）的工程突变菌株中投喂设计好的合成分子，来利用红霉素途径的生物合成潜力，以生成具有天然产物样复杂性的新型分子。我们这项技术的最初应用集中在改变6-dEB（C14-C15）的乙基侧链。我们现在报告将该方法扩展到对C-12取代基的修饰。一种经过适当设计的底物被证明可掺入6-dEB生物合成中，产生带有12-乙基的6-dEB类似物。这种6-dEB类似物是聚酮化合物后修饰酶的底物，并被转化为红霉素C的相应类似物。这些结果表明，许多下游活性位点能够耐受这种非天然官能团，并表明通过这种方法或通过基因工程进行全生物合成，应该可以获得各种各样的红霉素衍生物。
