Skip to main content
Log in

Optimal pH shift of the NADH oxidase from Lactobacillus rhamnosus with a single mutation

  • Original Research Paper
  • Published:
Biotechnology Letters Aims and scope Submit manuscript

Abstract

Objective

To improve the activity of a water-forming NADH oxidase from Lactobacillus rhamnosus under neutral or alkaline pH for coupling NAD+-dependent dehydrogenases with an alkaline optimal pH.

Results

The water-forming NADH oxidase from Lactobacillus rhamnosus was engineered by replacing the aspartic acid or glutamic acid with arginine on the surface. The mutant D251R improved the activity with a 112%, 111%, and 244% relative activity to the wild-type at pH 6.5, pH 7.0, and pH 7.5, respectively. Docking substrate into the D251R mutant reveals that the NADH is access to the substrate-binding site with a larger substrate loop due to the enhanced electrostatic repulsion between ARG-251 and ARG-243. In the D251R-NADH complex, the carboxyl of NADH additionally forms two hydrogen bonds (2.6 and 2.9 Å) with G154 due to the changed interaction of substrate and the residues in the catalytic sites, and the hydrogen bond with the oxygen of carbonyl in P295 is shortened from 2.9 to 2.0 Å, which could account for the enhanced specific activity.

Conclusions

The D251R mutant displayed higher catalytic activity than the wild-type in the pH range 6.5–7.5, and further insight into those shorter and newly formed hydrogen bonds in substrate docking analysis could account for the higher bind affinity and catalytic efficiency of D251R mutant.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5

Similar content being viewed by others

References

Download references

Acknowledgement

The authors appreciated the financial support from Natural Science Foundation of Guangxi province (2019GXNSFAA185059).

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Ye-Wang Zhang.

Ethics declarations

Conflict of interest

The authors declare that they have no conflict of interest.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary Information

Below is the link to the electronic supplementary material.

Supplementary file 1 (DOCX 991 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Zhou, Q., Gao, J. & Zhang, YW. Optimal pH shift of the NADH oxidase from Lactobacillus rhamnosus with a single mutation. Biotechnol Lett 43, 1413–1420 (2021). https://doi.org/10.1007/s10529-021-03129-7

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10529-021-03129-7

Keywords

Navigation