Surface active betaines as protective agents against denaturation of an enzyme by alkyl sulfate detergents

A homologous series of higher alkyl sulfate surfactants inactivate β‐fructofuranosidase (invertase) at levels coinciding with their critical micelle concentrations. It was possible to renature the enzyme by passing it through an anion exchange column. This inactivation was prevented by surface active betaines present at equimolar or higher concentrations than those of the anionics. Effective surfactant betaines include those with carboxylate, sulfonate, or phosphate radicals in their zwitterions. Betaines lacking surface active properties did not prevent denaturation indicating that the effects are due to comicellization. Studies with enzymes may point to appropriate anionic/zwitterionic surfactant ratios in solubilization procedures or detergent applications where biological properties must be preserved and anionic surfactants are required as components.