Skip to main content
Log in

Enzymatic properties of a non-classical aldoxime dehydratase capable of producing alkyl and arylalkyl nitriles

  • Biotechnologically Relevant Enzymes and Proteins
  • Published:
Applied Microbiology and Biotechnology Aims and scope Submit manuscript

Abstract

Nitriles are of significant interest in the flavor and fragrance industries with potential application in cosmetics due to their higher stability than analogous aldehydes. However, the traditional methods to prepare nitriles need toxic reagents and hash conditions. This work aimed to develop a chemoenzymatic strategy to synthesize nitriles from natural aldehydes with aldoxime as the intermediate. A non-classical aldoxime dehydratase (Oxd) was discovered from the fungus Aspergillus ibericus (OxdAsp) to catalyze the dehydration of aldoximes to corresponding nitriles under mild conditions. The amino acid sequence of OxdAsp exhibits an approximately 20% identity with bacterial Oxds. OxdAsp contains a heme prosthetic group bound with the axial H287 in the catalytic pocket. The structure models of OxdAsp with substrates suggest that its catalytic triad is Y138-R141-E192, which is different from the classically bacterial Oxds of His-Arg-Ser/Thr. The catalytic mechanism of OxdAsp was proposed based on the mutagenesis of key residues. The hydroxyl group of the substrate is fixed by E192 to increase its basicity. Y138 acts as a general acid-based catalyst, and its phenolic proton is polarized by the adjacent R141. The protonated Y138 would donate a proton to the hydroxyl group of the substrate and eliminate a water molecule from aldoxime to produce nitrile. The recombinant OxdAsp can efficiently dehydrate citronellal oxime and cinnamaldoxime to citronellyl nitrile and cinnamonitrile in aqueous media, which are applied as fragrance ingredients in the food and cosmetic fields.

Graphical abstract

Key points

A novel aldoxime dehydratase from the Aspergillus genus was first characterized as a heme-binding protein.

The catalytic mechanism was predicted based on the molecular interactions of the catalytic pocket with the substrate.

A chemoenzymatic strategy was developed to synthesize nitriles from natural aldehydes with aldoxime as the intermediate.

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
Fig. 6
Fig. 7
Fig. 8
Fig. 9

Similar content being viewed by others

Data availability

All data supporting the findings of this study are available within the paper and its Supplementary Information.

References

Download references

Funding

This study was financially supported by the Natural Science Foundation of Zhejiang Province (No. LY22B060003), the National Natural Science Foundation of China (No. 22078079), the Ten Thousand People Plan of Zhejiang Province (No. 2019R51012), and the College Students’ Innovative Entrepreneurial Training Plan Program (No. 202210346007).

Author information

Authors and Affiliations

Authors

Contributions

XP: resources, writing—review and editing—and supervision. QX: conceptualization, methodology, and writing—original draft. YF: formal analysis and data curation. LC: validation and investigation. FY: validation. QW: software and formal analysis. NL: methodology. AW: resources and supervision.

Corresponding authors

Correspondence to Xiaolin Pei or Anming Wang.

Ethics declarations

Ethics approval

This article does contain any studies involving human participants or animals.

Conflict of interest

The authors declare no competing interests.

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 file1 (PDF 1512 KB)

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Pei, X., Xiao, Q., Feng, Y. et al. Enzymatic properties of a non-classical aldoxime dehydratase capable of producing alkyl and arylalkyl nitriles. Appl Microbiol Biotechnol 107, 7089–7104 (2023). https://doi.org/10.1007/s00253-023-12767-y

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00253-023-12767-y

Keywords

Navigation