马乳脂肪球膜蛋白组鉴定及潜在功能分析

试验旨在研究马乳脂肪球膜（milk fat globule membrane，MFGM）蛋白组成及潜在的生物学功能。选取12匹5岁左右、平均体重为450~500 kg的健康纯血母马作为试验动物，主要饲喂干牧草，所有马匹饲养和管理条件均相同。将12份样品以每组4份进行混合，分离提取产后第60天马乳中MFGM蛋白，进行高分辨质谱仪鉴定和生物信息学分析。结果显示，马MFGM组分中共鉴定出310种表达蛋白，这些蛋白主要参与的生物过程为生物调节、刺激应答、定位、多细胞生物过程、运输、信号、细胞通讯、发育过程、细胞分化和免疫系统过程等；细胞成分主要为胞外区域、膜、囊泡、核仁和线粒体等；分子功能主要为催化活性、蛋白质结合、碳水化合物衍生物结合和小分子结合等。KEGG通路分析表明，MFGM蛋白主要参与血小板活化通路、内吞、脂肪酸生物合成和Ras信号通路等。马乳MFGM蛋白的蛋白质互作网络分析图中共包含215种蛋白质。本研究结果揭示了马乳MFGM蛋白质组的复杂性，为解析其营养和生物学功能提供了科学数据。

Proteome Identification and Potential Function Analysis of Milk Fat Globule Membrane in Horses

The purpose of this study was to investigate the protein composition and potential biological function of milk fat globule membrane (MFGM) in horses. Twelve healthy thoroughbred mares with 5 years old and body weight of 450-500 kg were selected as experimental animals, they were mainly fed with hay. The feeding-and-management conditions of all experimental horses were the similarity. 12 samples were mixed with 4 samples in each group, and MFGM proteins were isolated and extracted from horse milk on the 60th day after delivery. Of these, 4 individual sample was mixed and 3 biological samples were prepared. The tryptic peptides of samples were identified by high-resolution mass spectrometry and bioinformatics analysis. The results showed that 310 proteins were identified in MFGM fraction of horses, the identified MFGM proteins were mainly involved in biological regulation, stimulus response, localization, multicellular biological processes, transportation, signaling, cell communication, developmental processes, cell differentiation and immune system process on the basis of biological processes. They were mainly located in the extracellular area, membrane, vesicle, nucleolus and mitochondria according to cellular components. They were mainly involved in catalytic activity, protein binding, carbohydrate derivative binding and small molecule binding regarding of molecular functions. KEGG pathway analysis of MFGM proteins indicated that several proteins were involved in platelet activation pathway, endocytosis, fatty acid biosynthesis and Ras signaling pathways. The protein-protein interaction network analysis of MFGM protein in horses contained 215 proteins. The results of this study revealed the complexity of MFGM proteome in horses, and provided scientific data for analyzing its nutritional and biological functions.