One-Pot Synthesis of Useful S‑Substituted‑l‑cysteine Sulfoxides Using Genetically Engineered Escherichia coli

• Published in: Journal of agricultural and food chemistry 2024-03, Vol.72 (10), p.5339-5347
• Main Authors: Mizutani, Taku, Hara, Ryotaro, Takeuchi, Michiki, Hibi, Makoto, Ueda, Makoto, Ogawa, Jun
• Format: Article
• Language: English
• Subjects: Biotechnology and Biological Transformations; Cysteine - analogs & derivatives; Cysteine - metabolism; Escherichia coli - genetics; Genetic Engineering; Humans; Sulfoxides - metabolism
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/acs.jafc.3c08824

S-Substituted-l-cysteine sulfoxides are valuable compounds that are contained in plants. Particularly, (+)-alliin and its degraded products have gained significant attention because of their human health benefits. However, (+)-alliin production has been limited to extraction from plants and chemical synthesis; both methods have drawbacks in terms of stability and safety. Here, we proposed the enzymatic cascade reaction for synthesizing (+)-alliin from readily available substrates. To achieve a one-pot (+)-alliin production, we constructed Escherichia coli coexpressing the genes encoding tryptophan synthase from Aeromonas hydrophila ssp. hydrophila NBRC 3820 and l -isoleucine hydroxylase from Bacillus thuringiensis 2e2 for the biocatalyst. Deletion of tryptophanase gene in E. coli increased the yield about 2-fold. Under optimized conditions, (+)-alliin accumulation reached 110 mM, which is the highest productivity thus far. Moreover, natural and unnatural S-substituted-l-cysteine sulfoxides were synthesized by applying various thiols to the cascade reaction. These results indicate that the developed bioprocess would enable the supply of diverse S-substituted-l-cysteine sulfoxides.