Discovery of novel highly active and stable aspartate dehydrogenases

Aspartate family amino acids (AFAAs) have important commercial values due to their wide spectrum of applications. Most if not all AFAAs are produced under aerobic conditions which is energy-intensive. To establish a cost-effective anaerobic process for production of AFAAs, it holds great promise to...

Full description

Saved in:
Bibliographic Details
Published in:Scientific reports 2017-08, Vol.7 (1), p.7881-8, Article 7881
Main Authors: Li, Hao, Zhu, Taicheng, Miao, Liangtian, Zhang, Dan, Li, Yongxian, Li, Qi, Li, Yin
Format: Article
Language:English
Subjects:
631/45/612
631/61/252/318
82
82/80
82/83
Aerobic conditions
Amination
Amino acids
Ammonia
Anaerobic conditions
Aspartate aminotransferase
Aspartate ammonia-lyase
Dehydrogenases
E coli
Engineering
Enzymes
Fermentation
Histidine
Humanities and Social Sciences
Laboratories
Metabolism
multidisciplinary
Science
Science (multidisciplinary)
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Aspartate family amino acids (AFAAs) have important commercial values due to their wide spectrum of applications. Most if not all AFAAs are produced under aerobic conditions which is energy-intensive. To establish a cost-effective anaerobic process for production of AFAAs, it holds great promise to develop a new pathway enabling the conversion of oxoloacetate into aspartate through direct amination which is catalyzed by aspartate dehydrogenase (AspDH). Compared with the well studied aspartate aminotransferase and aspartate ammonia-lyase, only a few AspDHs are characterized till date, and failure to reproduce the high activity of AspDH from Rastonia eutropha documented in the literature encouraged us to screen and characterize novel AspDHs from different origins. Interestingly, the AspDHs from Klebsiella pneumoniae 34618 (KpnAspDH) and Delftia sp. Cs1–4 (DelAspDH) showed successful soluble expression. KpnAspDH and DelAspDH containing C-terminal hexa-histidine tags were purified and characterized for their catalytic properties. Notably, in addition to its high reductive amination activity, DelAspDH exhibited considerable stability as compared to the other source of AspDHs. This work thus provides novel enzyme resource for engineering strains capable of producing AFAAs under anaerobic conditions.
ISSN:2045-2322
2045-2322
DOI:10.1038/s41598-017-05522-7