Concurrent Oxidative and Reductive Protometabolic Reactions Driven by Electrochemistry

ABSTRACT The emergence of life is hypothesized to have been driven by a series of chemical processes constituting protometabolism, that are still preserved in the heart of biological metabolism, including numerous redox reactions. However, a longstanding problem is how critical oxidative and reductive protometabolic reactions could have been achieved simultaneously, especially in the absence of light. Here we show that electrochemistry can enable concurrent oxidative and reductive reactions relevant to protometabolism within a single environment. Using constant current and constant potential experiments, we promoted the reduction of oxaloacetate ( OXA ) to malate ( MAL ) and the oxidation of dihydroorotate ( DHO ) to orotate ( ORO ) and uracil ( URA ). Statistical modeling revealed that lower current densities favored ORO production from DHO , while higher densities promoted the oxidative decarboxylation of DHO to URA as well as the reduction of OXA to MAL . Additionally, we combine the oxidation of DHO to the reduction of other α‐keto acids (pyruvate and α‐ketoglutarate) and fumarate. Although the potentials used in this study exceed those presently known to occur in natural environments, the results nonetheless underscore the potential role of geological electromotive forces in enabling early metabolic networks.