Institut für Pharmazeutische Biologie und Biotechnologie, Philipps-Universität Marburg, Deutschhausstrasse 17A, 35037, Marburg, Germany.
Appl Microbiol Biotechnol. 2016 Jun;100(12):5389-99. doi: 10.1007/s00253-016-7365-3. Epub 2016 Feb 15.
FgaPT2 from Aspergillus fumigatus catalyzes a Friedel-Crafts alkylation at C-4 of L-tryptophan and is involved in the biosynthesis of the ergot alkaloids fumigaclavines. Several tryptophan-containing cyclic dipeptides had also been prenylated by FgaPT2, but the turnover rate (k cat) was low. Here, we report the generation of FgaPT2 mutants by saturation mutagenesis at the amino acid residue Arg244 to improve its catalytic efficiency toward cyclic dipeptides. Thirteen mutated enzymes demonstrated up to 76-fold higher turnover number toward seven cyclic dipeptides than the non-mutated FgaPT2. More importantly, the mutated enzymes exhibited different preferences toward these substrates. This study provides a convenient approach for creation of new biocatalysts for production of C4-prenylated cyclic dipeptides.
烟曲霉 FgaPT2 催化 L-色氨酸的 C-4 上的 Friedel-Crafts 烷基化反应，参与麦角生物碱呋咱生物碱的生物合成。几种含色氨酸的环二肽也被 FgaPT2 烯丙基化，但周转率 (kcat) 较低。在这里，我们通过饱和突变在氨基酸残基 Arg244 处生成 FgaPT2 突变体，以提高其对环二肽的催化效率。13 种突变酶对 7 种环二肽的周转数比非突变 FgaPT2 高 76 倍。更重要的是，突变酶对这些底物表现出不同的偏好。本研究为生产 C4-烯丙基化环二肽的新型生物催化剂的创造提供了一种便捷的方法。
