PDF(Pubmed)
Abstract：
Electron-rich phenolic substrates can be derived from the depolymerisation of lignin feedstocks. Direct biotransformations of the hydroxycinnamic acid monomers obtained can be exploited to produce high-value chemicals, such as α-amino acids, however the reaction is often hampered by the chemical autooxidation in alkaline or harsh reaction media. Regioselective O-methyltransferases (OMTs) are ubiquitous enzymes in natural secondary metabolic pathways utilising an expensive co-substrate S-adenosyl-l-methionine (SAM) as the methylating reagent altering the physicochemical properties of the hydroxycinnamic acids. In this study, we engineered an OMT to accept a variety of electron-rich phenolic substrates, modified a commercial E. coli strain BL21 (DE3) to regenerate SAM in vivo, and combined it with an engineered ammonia lyase to partake in a one-pot, two whole cell enzyme cascade to produce the l-DOPA precursor l-veratrylglycine from lignin-derived ferulic acid.
Protein and strain engineering combined. The combination of two engineered enzymes (a methyltransferase and an ammonia lyase) and an engineered E. coli strain (for regeneration of the SAM cofactor) has been developed to enable a fully biocatalytic one‐pot methylation–hydroamination cascade. As an example, the synthesis of l ‐veratrylglycine from renewable lignin‐derived ferulic acid has been demonstrated, in high yield and excellent ee.
Protein and strain engineering combined. The combination of two engineered enzymes (a methyltransferase and an ammonia lyase) and an engineered E. coli strain (for regeneration of the SAM cofactor) has been developed to enable a fully biocatalytic one‐pot methylation–hydroamination cascade. As an example, the synthesis of l ‐veratrylglycine from renewable lignin‐derived ferulic acid has been demonstrated, in high yield and excellent ee.
摘要：
富含电子的酚类底物可以源自木质素原料的解聚。获得的羟基肉桂酸单体的直接生物转化可用于生产高价值化学品，如α-氨基酸，然而，在碱性或苛刻的反应介质中，化学自氧化反应通常会阻碍反应。区域选择性O-甲基转移酶(OMT)是天然次级代谢途径中普遍存在的酶,其利用昂贵的共底物S-腺苷-1-甲硫氨酸(SAM)作为甲基化试剂改变羟基肉桂酸的物理化学性质。在这项研究中,我们设计了一个OMT来接受各种富含电子的酚醛底物，修饰的商业大肠杆菌菌株BL21（DE3）在体内再生SAM，并将其与工程化的氨裂解酶组合在一个锅中，从木质素衍生的阿魏酸产生I-DOPA前体I-veratyl甘氨酸的两个全细胞酶级联。
蛋白质和菌株工程相结合。已经开发了两种工程酶（甲基转移酶和氨裂解酶）和工程大肠杆菌菌株（用于SAM辅因子的再生）的组合，以实现完全生物催化的一锅法甲基化-加氢胺化级联。作为一个例子,已经证明了由可再生木质素衍生的阿魏酸合成左旋甘氨酸，在高产量和优良的ee。
蛋白质和菌株工程相结合。已经开发了两种工程酶（甲基转移酶和氨裂解酶）和工程大肠杆菌菌株（用于SAM辅因子的再生）的组合，以实现完全生物催化的一锅法甲基化-加氢胺化级联。作为一个例子,已经证明了由可再生木质素衍生的阿魏酸合成左旋甘氨酸，在高产量和优良的ee。
