Rxivist logo

Production of nonnatural straight chain amino acid 6-aminocaproate via an artificial recursive carbon-chain-extension cycle

By Jie Cheng, Tingting Song, Huayu Wang, Xiaohua Zhou, Michael P. Torrens-Spence, Dan Wang, Jing-Ke Weng, Qinhong Wang

Posted 05 Mar 2019
bioRxiv DOI: 10.1101/568121 (published DOI: 10.1016/j.ymben.2019.06.009)

Microbial bioplastics are present as promising and green alternatives to traditional petrochemical derived plastics. Nonnatural straight chain amino acids, especially 5-aminovalerate, 6-aminocaproate and 7-aminoheptanoate are potential monomers for the synthesis of bioplastics as their primary amine and carboxylic acid functional groups are ideal for polymerization. Previous pathways for 5-aminovalerate and 6-aminocaproate biosynthesis in microorganisms are derived from the L-lysine catabolism and citric acid cycle, respectively. Here we construct a novel biosynthetic route via artificial recursive carbon chain extension cycle for the simultaneous production of various chain length nonnatural amino acids. Overexpression of L-lysine α oxidase in Escherichia coli generates 2-keto-6-aminocaproate, the non-native substrate for the artificial recursive carbon chain extension cycle. The chain extended α-ketoacid is finally decarboxylated and oxidized by α-ketoacid decarboxylase and aldehyde dehydrogenase, respectively, to yield the nonnatural straight chain amino acid products. The recursive nature of this pathway used 2-keto-6-aminocaproate as substrate was first demonstrated in vitro with the simultaneous production of 99.16 mg/L of 5-aminovalerate, 46.96 mg/L of 6-aminocaproate and 4.78 mg/L of 7-aminoheptanoate after 8 h of enzyme catalysis. Furthermore, 2.179 g/L of nonnatural straight chain amino acids could be achieved by strain BL21(DE3) plus plasmids pIVC4 and pETaRKP, which simultaneously yields 2.15 g/L of 5-aminovalerate, 24.12 mg/L of 6-aminocaproate and 4.74 mg/L of 7-aminoheptanoate. The production of 6-aminocaproate and other nonnatural straight chain amino acids via the artificial recursive carbon chain extension cycle provides a potential strategy to produce other medium chain length acids with -NH2, -SCH3, -SOCH3, -SH, -COOH, -COH, -OH, etc. functional groups by carbon chain elongation.

Download data

  • Downloaded 470 times
  • Download rankings, all-time:
    • Site-wide: 71,486
    • In synthetic biology: 836
  • Year to date:
    • Site-wide: 103,632
  • Since beginning of last month:
    • Site-wide: 64,448

Altmetric data

Downloads over time

Distribution of downloads per paper, site-wide