The Molecular Mechanism of ES Improved Beef Tenderness Identified by
Two-Dimensional Protein Electrophoresis
Differential proteomics in electrical stimulated M. longissimus of Chinese yellow crossbred
bulls (ES: 42 V, 50 Hz, 0.7 A for 40 sec) were carried out using two-dimensional electrophoresis technology.
Twelve protein spots had reduced expression at 1 and 3 days post Electrical Stimulation (ES) of samples which
were divided into nine categories: desmin, troponin T alpha isoform, myosin binding protein H, creatine kinase
(two), triosephosphateisomerase (two), peroxiredoxin-6 (two), phosphatidylethanolamine-binding protein,
histone H3.3-like isoform 2, methyltransferase. Biological function analysis of these proteins indicated ES
affected tenderness via four pathways: glycolytic metabolic pathway, calpains pathway, lysosomal pathway
and oxidative stress pathway. Correspondingly, we concluded that ES could accelerate the decline of pH and
the release of lysosomal enzymes, activate the calpain system and accelerate oxidation and apoptosis. All these
combined effects accelerate the meat tenderization process. Results provide a relatively comprehensive
understanding of the influences that ES exerted on beef tenderness improvement from the perspective of
proteins changing. Furthermore, the results indicate that more attention should be paid on the contribution of
lysosomal to beef tenderness and the effects of oxidative stress on beef tenderness point out the further
research direction and related experiments have been designed to verify such specific mechanism.