Vibrio natriegens: An Alternative Expression System for the High-Yield Production of Isotopically Labeled Proteins.

Isotopic labeling of recombinant proteins is crucial for studying proteins by liquid state NMR spectroscopy. Nowadays, conventional E. coli-based expression systems like BL21 (DE3) are typically used to express recombinant proteins. Still, the production of isotopically labeled proteins is often costly and time-consuming, and yields are not sufficient enough for structural studies. Here, we present Vibrio natriegens (Vmax) as an alternative expression system in M9 minimal medium. Due to our optimized M9 minimal medium and conditions and the early time point of induction, we obtained a 2- to 4-fold higher protein yield for two test proteins, FKBP and EYFP, compared to E. coli BL21 (DE3). Production of proteins in V. natriegens in minimal medium is not only more cost-effective and convenient but also less time-consuming than in E. coli. Comparing 15N HSQC spectra of FKBP and EYFP expressed in Vmax and BL21 (DE3) revealed correct folding during expression.