Methods of treating a subterranean formation comprising providing a viscosified treatment fluid that comprises a base fluid and a gelling agent, providing a breaker composition that comprises an oxidizing breaker and a breaker activator that comprises a metal and a protein, allowing the viscosified treatment fluid to interact with the breaker composition, treating the subterranean formation with the viscosified treatment fluid, and allowing a viscosity of the viscosified treatment fluid to be reduced. Further, methods of reducing the viscosity of a viscosified treatment fluids and methods of activating oxidizing breakers are also provided.