Identification of specific oxidatively modified proteins in chicken muscles using a combined immunologic and proteomic approach

Muscle proteins are generally believed to be key players in free radical processes that eventually lead to oxidative deterioration or modifications of meat proteins resulting in alterations in functionality, for example, gel-forming ability, emulsification properties, and water-binding capacity. This study addresses protein oxidation in chicken muscles using a combined immunologic and proteomic approach and identifies specific proteins that contain carbonyls and/or 3-nitrotyrosine (3-NT). Whereas a-enolase was the predominant carbonyl-reactive species among the water-soluble muscle proteins, several other proteins (actin, heat shock protein 70, and creatine kinase) contained carbonyls and/or 3-nitrotyrosine. Finally, this approach was used to demonstrate differential susceptibility of water-soluble muscle proteins toward oxidation in chickens fed a low-antioxidant diet compared with chickens fed a diet supplemented with antioxidant-rich fruits/vegetables.