Cofactor Specificity Engineering of Streptococcus mutans NADH Oxidase 2 for NAD (P)+ Regeneration in Biocatalytic Oxidations

Barbara Petschacher, Nicole Staunig, Monika Mueller, Martin Schuermann, Daniel Mink, Stefaan Wildemann, Karl Gruber, Anton Glieder*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Soluble water-forming NAD(P)H oxidases constitute a promising NAD(P)+ regeneration method as they only need oxygen as cosubstrate and produce water as sole byproduct. Moreover, the thermodynamic equilibrium of O2 reduction is a valuable driving force for mostly energetically unfavorable biocatalytic oxidations. Here, we present the generation of an NAD(P)H oxidase with high activity for both cofactors, NADH and NADPH. Starting from the strictly NADH specific water-forming Streptococcus mutans NADH oxidase 2 several rationally designed cofactor binding site mutants were created and kinetic values for NADH and NADPH conversion were determined. Double mutant 93R94H showed comparable high rates and low Km values for NADPH (kcat 20 s−1, Km 6 μM) and NADH (kcat 25 s−1, Km 9 μM) with retention of 70 % of wild type activity towards NADH. Moreover, by screening of a SeSaM library S. mutans NADH oxidase 2 variants showing predominantly NADPH activity were found, giving further insight into cofactor binding site architecture. Applicability for cofactor regeneration is shown for coupling with alcohol dehydrogenase from Sphyngobium yanoikuyae for 2-heptanone production.
Original languageEnglish
Pages (from-to)1-11
JournalComputational and Structural Biotechnology Journal
Issue number14
Publication statusPublished - 2014

Fields of Expertise

  • Human- & Biotechnology

Treatment code (Nähere Zuordnung)

  • Experimental

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