秦川牛宰后成熟过程中线粒体Tu翻译延长因子对牛肉持水性的影响

Effect of Mitochondrial Tu Translation Elongation Factor on Water-holding Capacity of Qinchuan Cattle Meat during Postmortem Aging

探究秦川牛宰后成熟过程中线粒体Tu翻译延长因子(mitochondrial Tu translation elongation factor,TUFM)表达对肉的持水性影响。以秦川牛背最长肌为研究对象,测定4℃不同成熟时间下的pH值、贮藏损失、离心损失、蒸煮损失、水分分布、肌原纤维蛋白等指标变化情况,测定不同成熟时间(0、96、192 h)下TUFM表达量及其含量、Beclin1蛋白表达量。结果显示:在秦川牛宰后成熟期间,肌原纤维蛋白发生降解,TUFM的表达量与Beclin1蛋白表达量和牛肉的持水性存在密切关系,其中蛋白质组学测定的TUFM表达量变化与TUFM含量变化趋势一致,Beclin1蛋白表达量、贮藏损失、离心损失、蒸煮损失整体均呈先上升后下降趋势,pH值呈先下降后上升趋势;Pearson相关性分析表明,牛背最长肌中TUFM表达量与低场核磁共振峰面积比P_(2b)、Beclin1蛋白表达量呈极显著正相关(P<0.01),与贮藏损失、离心损失、蒸煮损失呈显著正相关(P<0.05),与P_(21)呈极显著负相关(P<0.01),与P_(22)呈显著负相关(P<0.05),与pH值无显著相关性(P>0.05)。通过蛋白质组学鉴定出23种与TUFM相关的差异蛋白,通过基因本体论、京都基因与基因组百科全书通路分析发现,差异蛋白可通过多种途径参与能量代谢,进而介导细胞自噬;对差异蛋白和持水性指标进行Pearson相关性分析发现,有5种差异蛋白(ATP5F1D、EEF1A2、GSPT1、NDUFB5、SUCLG1)与持水性指标具有显著相关性(P<0.05、P<0.01)。分析可知,包括TUFM在内,共6种蛋白主要通过能量代谢和氧转运等途径正向或负向影响细胞自噬,从而影响肉的持水性。

In order to investigate the effect of mitochondrial Tu translation elongation factor(TUFM)expression on the water-holding capacity(WHC)of meat during the postmortem aging of Qinchuan cattle meat,changes in the pH,storage loss,centrifugal loss,cooking loss,and water distribution of the longissimus dorsi of Qinchuan cattle as well as its myofibrillar protein degradation were determined after different aging durations at 4℃.Besides,TUFM expression and content as well as beclin 1 expression were examined after 0,96 and 192 h of aging.The results showed that myofibrillar protein was degraded during the postmortem aging process,and there was a close relationship between the expression of TUFM and beclin1 protein and the WHC of beef.Proteomics revealed consistent changing trends between the expression of TUFM and its content.In general,beclin1 protein expression,storage loss,centrifugal loss,and cooking loss initially increased and subsequently decreased,whereas the opposite was true for pH.Pearson’s correlation analysis showed that the expression of TUFM was highly significantly positively correlated with low-field nuclear magnetic resonance peak area ratio P_(2b) and beclin 1 protein expression(P<0.01),significantly positively correlated with storage loss,centrifugal loss,and cooking loss(P<0.05),highly significantly negatively correlated with P_(21)(P<0.01),and significantly negatively correlated with P_(22)(P<0.05),but had no significant correlation with pH(P>0.05).Through proteomics,23 differential proteins related to TUFM were identified,and Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis showed that the differential proteins could mediate cellular autophagy by participating in energy metabolism through a variety of pathways.Pearson’s correlation analysis showed that five differential proteins(ATP5F1D,EEF1A2,GSPT1,NDUFB5,and SUCLG1)were significantly correlated with WHC(P<0.05,P<0.01).From these analyses,it is clear that there are six proteins including TUFM that affect the WHC of meat by affecting cellular autophagy positively or negatively through various pathways such as energy metabolism and oxygen transport.