Superanionic Solvent‐Free Liquid Enzymes Exhibit Enhanced Structures and Activities

The surface of a carboxylate‐enriched octuple mutant of Bacillus subtilis lipase A (8M) is chemically anionized to produce core (8M)‐shell (cationic polymer surfactants) bionanoconjugates in protein liquid form, which are termed anion‐type biofluids. The resultant lipase biofluids exhibit a 2.5‐fold increase in hydrolytic activity when compared with analogous lipase biofluids based on anionic polymer surfactants. In addition, the applicability of the anion‐type biofluid using Myoglobin (Mb) that is well studied in anion‐type solvent‐free liquid proteins is evaluated. Although anionization resulted in the complete unfolding of Mb, the active α‐helix level is partially recovered in the anion‐type biofluids, and the effect is accentuated in the cation‐type Mb biofluids. These highly active anion‐type solvent‐free liquid enzymes exhibit increased thermal stability and provide a new direction in solvent‐free liquid protein research.