Proteomic Profiling of Lipoxidation-Induced Modification on Myofibrillar Proteins from Bighead Carp (Hypophthalmichthys Nobilis) by Linoleic Acid and 4-Hydroxy-2-Nonenal

Abstract

To investigate the effect of 4-hydroxy-2-nonenal (HNE) on myofibrillar proteins (MPs) from bighead carp, their amino acid content, solubility, and the site specificity of modification were analyzed in MPs post-HNE and linoleic acid (LA)-oxidation systems. We found 1) The LA-oxidation system could cause the MPs' aggregation and decreased solubility, which was primarily caused by the peroxide generation; 2) Beside myosin heavy chain (MHC) tail, HNE was susceptible to binding on the MHC's amino acids located in 180-187 which might influence the binding of ATP to MHC; 3) The prime modification in MPs were oxidation and HNE-adduct in both treatment system. And more basic amino acids such as Lys and Arg in MPs were modified post-HNE. In conclusion, this study fills in the mechanism of lipid-promoted protein oxidation in fish and sheds light on the HNE modification sites of MPs, paving the way for the development of oxidation control technology.

Keywords: 4-hydroxy-2-nonenal, linoleic acid, myofibrillar proteins.