Gao Ruichen, Li Zhimin
State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China.
Shanghai Collaborative Innovation Center for Biomanufacturing Technology, 130 Meilong Road, Shanghai 200237, China.
J Agric Food Chem. 2021 Mar 31;69(12):3712-3719. doi: 10.1021/acs.jafc.1c00494. Epub 2021 Mar 18.
3-Hydroxy-3-methylbutyrate (HMB) is an important compound that can be used for the synthesis of a variety of chemicals in the food and pharmaceutical fields. Here, a biocatalytic method using l-leucine as a substrate was designed and constructed by expressing l-amino acid deaminase (l-AAD) and 4-hydroxyphenylpyruvate dioxygenase (4-HPPD) in . To reduce the influence of the rate-limiting step on the cascade reaction, two 4-HPPD mutants were screened by rational design and both showed improved catalytic activity. Under optimal reaction conditions, the maximum conversion rate and production rate were 80% and 0.257 g/L·h, respectively. HMB production could be realized with high efficiency without an additional supply of adenosine triphosphate (ATP), which successfully overcomes the shortcomings of chemical production and fermentation methods. This design-based strategy of constructing a whole-cell catalyst system from l-leucine might serve as an alternative route to HMB synthesis.
3-羟基-3-甲基丁酸酯（HMB）是一种重要的化合物，可用于食品和制药领域中多种化学品的合成。在此，通过在[具体表达系统]中表达L-氨基酸脱氨酶（L-AAD）和4-羟基苯丙酮酸双加氧酶（4-HPPD），设计并构建了一种以L-亮氨酸为底物的生物催化方法。为了减少限速步骤对级联反应的影响，通过合理设计筛选出两个4-HPPD突变体，二者均表现出提高的催化活性。在最佳反应条件下，最大转化率和产率分别为80%和0.257 g/L·h。无需额外供应三磷酸腺苷（ATP）即可高效实现HMB的生产，这成功克服了化学生产和发酵方法的缺点。这种基于设计从L-亮氨酸构建全细胞催化剂系统的策略可能成为HMB合成的替代途径。
