EAPSI: Modeling an Environmentally Friendly Catalytic Mechanism to Convert Wax-Covered Poultry Waste into Digestible Protein Meal

Barcus Matthew, Ithaca NY

Investigators

Abstract

Natural waxes in animals provide their hosts with a form of energy storage or waterproof protection from elements. Waxy lipids present on the surface of chicken feathers, a large waste product from the poultry industry, is thought to hinder biological rendering of the feathers into digestible protein meal for use in animal agriculture. Wax ester hydrolases are a potential catalyst to assist in breaking down the waxes in an environmentally sound way. A biocatalyst with demonstrated ability to hydrolyze wax esters has been sourced from a feather-degrading microorganism found in soil. In collaboration with Dr. Shinya Fushinobu, an expert protein crystallographer at the University of Tokyo in Japan, the project will determine the three-dimensional structure of the biocatalyst as a means to understand its molecular mechanism. This information will advance understanding of biocatalyst function, which can then be used to design a biocatalyst with improved properties to better aid in feather rendering and adaptations for use in other industries such as health care, cosmetics, nutrition, and energy. A wax-ester hydrolase gene was cloned from a gram-positive Streptomycete isolated from the soil and capable of hydrolyzing chicken feathers. The gene will be heterologously expressed in E. coli, then purified and concentrated for the structure research in the lab of Dr. Fushinobu. Favorable parameters to grow crystals of the enzyme will be determined and optimized using a hanging drop crystallization test. Crystals will then be cryoprotected and used to collect diffraction data using beamlines with a charged couple device camera at the High Energy Accelerator Research Organization (KEK) in Tsukuba, Japan. After processing the data using the HKL2000 software package, a combination of computational tools will be used to refine and analyze the structural models of the biocatalyst. Based on the determined structure of the wax-ester hydrolase, the enzyme will be rationally designed for improving its stability and catalytic efficiency. This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Japan Society for the Promotion of Science.