Dept. of Biotechnology & Enzyme Catalysis, Institute of Biochemistry, University of Greifswald, Felix-Hausdorff-Straße 4, 17489, Greifswald, Germany.
Chembiochem. 2022 May 18;23(10):e202200062. doi: 10.1002/cbic.202200062. Epub 2022 Apr 7.
p-Coumaric acid (p-CA) is a key precursor for the biosynthesis of flavonoids. Tyrosine ammonia lyases (TALs) specifically catalyze the synthesis of p-CA from l-tyrosine, which is a convenient enzymatic pathway. To explore novel and highly active TALs, a phylogenetic tree-building approach was conducted including 875 putative TALs and 46 putative phenylalanine/tyrosine ammonia lyases (PTALs). Among them, 5 TALs and 3 PTALs were successfully characterized and found to exhibit the proposed enzymatic activity. The TAL from Chryseobacterium luteum sp. nov (TAL ) has the highest affinity (K =0.019 mm) and conversion efficiency (k /K 1631 s ⋅ mm ) towards l-tyrosine. The reaction conditions for two purified enzymes and their E. coli recombinant cells were optimized and p-CA yields of 2.03 g/L after 8 hours by TAL and 2.35 g/L after 24 h by TAL from Rivularia sp. PCC 7116 (TAL ) in whole cells were achieved. These TALs are thus candidates for the construction of whole-cell systems to produce the flavonoid precursor p-CA.
对羟基肉桂酸（p-CA）是黄酮类化合物生物合成的关键前体。酪氨酸氨裂解酶（TALs）特异性地催化 l-酪氨酸合成 p-CA，这是一种方便的酶促途径。为了探索新型且高活性的 TALs，采用系统发育树构建方法，包括 875 个推定的 TAL 和 46 个推定的苯丙氨酸/酪氨酸氨裂解酶（PTAL）。其中，成功鉴定了 5 个 TAL 和 3 个 PTAL，并发现它们具有预期的酶活性。来自黄杆菌属（Chryseobacterium luteum sp. nov）的 TAL（TAL）对 l-酪氨酸具有最高的亲和力（K=0.019mm）和转化效率（k/K1631 s ⋅mm）。两种纯化酶及其大肠杆菌重组细胞的反应条件进行了优化，TAL 产生的 p-CA 产量为 8 小时后 2.03g/L，而 Rivularia sp. PCC 7116（TAL）的全细胞中 24 小时后可达 2.35g/L。因此，这些 TAL 是构建全细胞系统生产黄酮类化合物前体 p-CA 的候选酶。
