本研究将羊乳、牛乳、人乳中乳清蛋白进行分离并结合液质联用技术鉴定，在羊乳、牛乳、人乳乳清蛋白中分别鉴定出156、278、454种蛋白质。与牛乳与人乳乳清蛋白对比显示，羊乳含有99种特异性表达蛋白质，与牛乳和人乳分别有31种和15种相同表达蛋白质。通过分析基因本体（gene ontology，GO）功能注释发现，羊乳乳清蛋白在生物过程中主要发挥生物调节作用；在分子功能上，主要体现在结合作用方面；在细胞组成上，参与的细胞组成主要为细胞器区和胞外区。羊乳乳清蛋白在以上三种功能上与人乳有较大差距，但与牛乳相近。通过分析京都基因与基因组百科全书系统（Kyoto Encyclopedia of Genes and Genomes，KEGG）代谢通路可知，羊乳主要参与补体和凝血级联反应以及吞噬作用，对人体免疫能力有积极影响。对羊乳与人乳、牛乳乳清蛋白组成及功能区别的研究，为羊乳的进一步研究和开发提供一定的理论参考。

Whey protein was separated from goat milk, bovine milk and human milk and identified by combined liquid chromatography and mass spectrometry in this study, and 156, 278 and 454 proteins were identified in whey protein of goat milk, bovine milk, and human milk. Compared with the whey protein of bovine milk and human milk, there were 99 specific expression proteins in whey protein of goat milk, and there were 31 and 15 identical proteins expressed in bovine milk and human milk, respectively. The results of gene ontology (GO) annotations analysis showed that the whey protein of goat milk played a biological regulation in biological process, and its molecular function was mainly embodied in the binding effect. In cellular component, the whey protein of goat milk in cell was mainly participated in the composition of organelle region and the extracellular region. The whey protein of goat milk had a large gap with human milk in the above three functions, but it was similar to bovine milk. KEGG pathway analysis showed that the whey protein of goat milk was mainly involved in the complement and coagulation cascade reaction and phagocytosis, which had a positive impact on human immunity. Consequently, the study on the composition and functional difference among goat milk, bovine milk and human milk could provide a theoretical reference for further research and development of goat milk.

“十二五”农村领域国家科技计划课题（2013BAD18B03-02）