摘要以青藏高原有机牦牛为研究对象，采用超声波破碎法提取生鲜和冷藏有机牦牛背最长肌肌肉蛋白，Bradford法进行蛋白质定量后，进行双向电泳，通过PD Quest凝胶图像分析软件筛选3 倍或3 倍以上的差异斑点进行基质辅助激光解析串联飞行时间质谱（matrix-assisted laser desorption/ionization time of flight to time of fight，MALDI-TOF-TOF），并用Mascot软件鉴定差异蛋白，以建立青藏高原有机牦牛生鲜肉和冷藏肉背最长肌差异蛋白质组学研究方法。结果表明：经双向电泳图谱分析所获得的青藏高原有机牦牛生鲜肉和冷鲜肉背最长肌肌肉蛋白斑点数分别为1 840±181和2 034±86，分布于pH 3.0～10.0之间，PD Quest软件筛选青藏高原有机牦牛生鲜肉和冷藏肉背最长肌差异3 倍或3 倍以上蛋白质斑点36 个，其中生鲜肉相比冷藏肉有机牦牛背最长肌肌肉蛋白上调的有12 个点，下调的有24 个点，质谱鉴定有意义的差异蛋白质点7 个（蛋白质得分＞65）（P＜0.05），其中2 种蛋白质表达量上调，5 种蛋白质表达量下调。
Abstract：This paper proposes a methodology for investigating the differential proteomics of fresh and refrigerated
longissimus dorsi muscles of organically raised yaks from the Qinghai-Tibetan plateau. Protein extraction from longissimus
dorsi muscles was performed through ultrasonic cell disruption. The extracted protein was quantitated by the Bradford
method and analyzed by two-dimensional electrophoresis (2-DE). PD Quest gel image analysis software was used to
screen ≥ 3-fold differential protein spots for analysis by matrix-assisted laser desorption/ionization time of flight/time-offlight
mass spectrometry (MALDI-TOF-TOF-MS) and the proteins were identified using Mascot software. The results
showed that 1 840±181 and 2 034±86 protein spots from fresh and refrigerated longissimus dorsi muscles, distributed in
the pH range of 3.0–10.0, were respectively observed in the 2-DE gels. A total of 36 protein spots with ≥ 3-fold differences
from fresh and refrigerated muscles were screened out, including 12 upregulated ones and 24 downregulated ones in fresh
longissimus dorsi as compared to refrigerated longissimus dorsi. Seven differential protein spots of significance (with a score
greater than 65) were identified by mass spectrometry (MS), 2 of which were up-expressed and 5 down-expressed.
