Salt-driven dynamic folding of halophile-origin enzymes: Insights into evolution and protein exploitation

Many years ago, life transitioned from the ocean to land, evolving from halophilic to non-halophilic organisms. Our research indicates that some enzymes from halophiles require salt for soluble expression in E. coli and retain activity within certain salt concentration ranges in the growth medium. The cytoplasmic electrical resistance varies in accordance with the salt concentration in the medium. Further experiments and simulations reveal that the protein structure undergoes dynamic and sophisticated changes under different salt concentrations, affecting soluble expression, surface charge and enzyme activity. This suggests that salt concentrations affect enzyme functionality and potentially influence overall metabolic processes, pointing to a sophisticated adaptive system that operates independently of genetic molecules. Our findings propose insights into a type of environmental cue induced evolution of halophilic microorganisms from the perspective of protein structure. Ultimately, given our extensive marine and other saline resources, our research lays a foundational basis for the development and utilization of halophile-origin enzymes.