loading page

Cell@MOF nanocomposites with improved catalytic performance for the enzymatic biosynthesis of Ala-Gln
  • +6
  • xiang-e chen,
  • Heng-jun Di,
  • Xue-dan Liu,
  • Shu-xuan Li,
  • Ting Cheng,
  • Fei-yang Zhao,
  • Xiao-huan Liu,
  • Hao-geng Chen,
  • Tao Wang
xiang-e chen
Author Profile
Heng-jun Di
Author Profile
Xue-dan Liu
Author Profile
Shu-xuan Li
Author Profile
Ting Cheng
Author Profile
Fei-yang Zhao
Author Profile
Xiao-huan Liu
Author Profile
Hao-geng Chen
Author Profile
Tao Wang

Corresponding Author:[email protected]

Author Profile


Recently, zeolitic imidazolate frameworks (ZIFs) with tunable pore sizes and large surface areas have been widely used as effective supports for enzyme immobilization. A bienzyme system for the biosynthesis of L-alanyl-L-glutamine (Ala-Gln) with effective ATP regeneration was established in this study. Cells (E. coli BL21 (DE3)) expressing L-amino acid ligase (Lal) from Bacillus altitudinis (BABD) and polyphosphate kinase (PPK) were immobilized on ZIF-8 using a one-step molecular organic framework (MOF)-embedded approach. The immobilized bienzyme system, named BP@ZIF-8, was successfully fabricated and characterized using Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The resulting BP@ZIF-8 exhibited high thermostability at 50 °C and high pH stability in neutral and alkaline reaction buffers. BP@ZIF-8, for example, lost little activity after 150 minutes in carbonate buffer solution (pH 10.0). However, BP@ZIF-8 displayed poor pH stability in acidic environments. Furthermore, after seven successive uses, it still maintained 58.9% of their initial activity, exhibiting satisfactory reusability. After 14 hours, the yield of Ala-Gln catalysed by BP@ZIF-8 was around 14.56 mM, which represented an increase of roughly 14.3% above that catalysed by free cells. These findings showed that BP@ZIF-8 has a great deal of potential for practical Ala-Gln biosynthesis.