牦牛与黄牛肌肉差异蛋白质组及生物信息学分析

为了建立和优化牦牛肌肉组织蛋白质双向电泳(2DE)体系,结合生物信息学方法进行牦牛、黄牛差异蛋白质通路分析。以牦牛背最长肌为实验材料,对不同裂解液成分、等电聚焦程序、染色方法进行研究,在最优2DE体系参数下,对比分析牦牛、黄牛差异倍数大于2倍且达到显著水平(P0.05)的19个蛋白质,通过基质辅助激光解吸/电离飞行时间(MALDI-TOF/TOF)质谱进行鉴定,并对鉴定结果进行了基因本体(GO)注释、京都基因与基因组百科全书(KEGG)通路分析。结果表明,裂解液II、渐进式快速升压程序、改良的考染法获得的蛋白点匹配率高,牦牛、黄牛2DE图谱蛋白点平均个数分别为479个和553个。通过比较牦牛和黄牛背最长肌中差异蛋白质可知,所得到的差异蛋白质按照功能可分为代谢酶、结构蛋白和应激蛋白3大类。通过KEGG分析可知,牦牛、黄牛差异蛋白质主要集中在细胞代谢过程、碳水化合物代谢通路、遗传信息通路和能量代谢通路中,研究结果可为解释牦牛和黄牛肌肉生物学特性和肉品质差异提供理论依据。

Proteomics and Bioinformatics Analyses of Differentially Expressed Proteins in Yak and Beef Cattle Muscle

Yak (Bos grunniens) lives at plateau area of more than 3500 altitude meter, in this case, yak still maintains normal physiological activity. Besides, yak meat is rich in protein and low in fat, which does not contain anabolic steroids. Proteomics research with bioinformatics approach combined with the established two dimensional electrophoresis (2DE) platforms was studied by comparing yak with beef cattle muscle. Aiming to illustrate the causes and pathway of different meat qualities in yak and beef cattle, establish the optimal 2DE system and analyze protein bioinformatics pathways, different lysis buffer components, isoelectric focusing procedures and staining methods were studied by using longissimus dorsi muscle of yak. Proteomic profiling by 2DE and mass spectrometry identified 19 proteins that were differentially expressed in longissimus dorsi muscle of yak and beef cattle. Then the identified proteins were analyzed by gene ontology (GO) annotations and Kyoto encyclopedia of genes and genomes (KEGG) pathway. Results showed that the optimal protein extraction methods were lysis buffer component II, progressive fast boosting program and improved coomassie blue staining method. And protein spots in yak and beef cattle were 553 and 479, respectively. Totally 19 protein spots exhibiting a teo fold or more intensity difference in the meantime associated with 5% statistical significance (P<0.05) were considered differentially abundant. The differentially abundant proteins between yak and beef cattle could be divided into three main functional categories: metabolism proteins, structure proteins and stress proteins. The method of GO annotation provided three detailed and structured terms that included cellular component, molecular function and biological process. The differentially expressed proteins in yak and beef cattle muscle were concentrated in cellular processes, carbohydrate metabolism, genetic information processing and energy metabolism pathways by KEGG pathway analysis. In conclusion, the research result demonstrated the functions of identified proteins and provided a more detailed molecular view of the processes behind meat quality in yak and beef cattle.