Bidirectional electro-enzymatic reaction of coenzyme F using benzyl viologen and F-dependent sulfite reductase.

Coenzyme F is recognized as a crucial electron carrier in methane-generating metabolism but, beyond this, has garnered significant attention for its role in diverse microbial physiologies and relevance in industrial, medical, and environmental applications. However, one limitation of current application of F is the necessity of chemical electron donors for its reduction. In this study, an electrochemical reaction system was designed to facilitate electron transfer between the electrode and F using F-dependent sulfite reductase (Fsr) as the catalyst and benzyl viologen (BV) as the redox mediator.

Quantitative analysis of underivatized amino acids in the sub- to several-nanomolar range by ion-pair HPLC using a corona-charged aerosol detector (HPLC-CAD).

The separation and quantification of underivatized naturally occurring amino acids (AAs) by high-performance liquid chromatography (HPLC) is advantageous for reducing preparation time, running costs, and analytical errors, and is compatible with the isolation of intact AAs. This study establishes and validates an analytical method for the separation and quantification of underivatized AAs and taurine (Tau) in the sub- to several-nanomolar range (ca. 0.