Study On Diversity Of Chinese Cattle M.Longissimus Lumborum Quality Using Proteomics

Proteomics is an important cornerstone in functional genome characterization. Proteome studies aim to translate genome information into useful biological information. In recent years, proteomics in meat science has been applied to achieve a better understanding of mechanisms underlying meat product quality. Muscle is composed by protein, so the study on proteomics is very important to understanding meat quality. No matter how to exert influence on meat, it will show on protein.However, previous studies in meat science focused on the differences between treated and untreated groups. Qualitative differences, such as breeds, were not investigated.In addition, chilling method was more and more studied in recent years. But mechanism on molecular level was dimness, it need to be studied on proteomics.Described on the final, this study is aiming at research the effect of different breeds and chilling methods on proteomics of beef. Also will we relate the protein on meat quality.Grind method and other parameters were optimized in this experiment. Best parameters in beef proteomics was list as follow:samples were grinded using mortar, the content of DTT was 1%, parameter of IEF was 100V,0.5h; 500V,0.5h; 1000V,1.5h; Grd8000V,2h; 8000V and totally 70000V*h.The study showed a total of 17 differentially expressed proteins were identified at 72 h postmortem. Qinchuan cattle were found to have significantly faster rates in energy shifts than Yanbian cattle. However, Yanbian cattle were found to have significantly higher rates of degradation of structural proteins than Qinchuan cattle. Western blotting analysis showed Yanbian cattle had a higher degradation rate of troponin-T. These differences could potentially affect meat quality.There were 5 differentially expressed proteins between three step chilling and traditional chilling. There were 2 protein expressed more in three step chilling and 3 protein expressed more in traditional chilling. Enol protein and creatine kinase indicated faster rate of energy metabolism in three step chilling. However, heat shock protein and cofilin-2 indicated these two proteins made more in polymerization and depolymerization of proteins.