牦牛乳是青藏高原特有资源，是藏区重要经济支柱，由于牦牛乳基础研究缺乏，严重制约了牦牛乳产品开发与藏区经济发展。酪蛋白胶束结构决定乳制品品质和功能，但目前缺乏胶束结构形成机理研究。本课题利用分子生物学和蛋白组学技术手段，探讨牦牛乳酪蛋白胶束结构形成的分子机理。首先采用高效液相色谱、离子色谱等技术研究酪蛋白胶束化学组成，明确胶束内部主要酪蛋白单体和矿物质含量；采用飞行时间质谱、红外光谱、圆二色光谱等技术确定4种主要酪蛋白单体氨基酸组成、序列及空间构象；采用小角X射线和中子射线散射技术获得胶束内部空腔尺寸、磷酸钙粒径及其分布信息，探明胶束内部结构；采用表面等离子体共振、原子力显微技术，从分子水平分析酪蛋白单体间相互作用关系，明确作用机制；利用胶束结构模型理论，阐明牦牛乳酪蛋白胶束结构形成机理，提出特征结构形成控制参数，调控酪蛋白胶束微观结构，开发功能酪蛋白产品，带动藏区经济发展，促进牧民增收。

Yak milk is the specific resources and an important economic materials in Qinghai-Tibet Plateau. However, due to the lack of systematic and in-depth study, yak milk are in low output state and yak milk products are scarce which hinder the economic growth of Qinghai-Tibet Plateau. Casein micelles are at the core of dairy industry which structure affects the properties of milk and casein products. Up to now, little research was carried out to investigate the formation mechanism of casein micelles on a molecular level. In this study, proteomics advanced technology will be used to investigate the formation mecheanism of yak casein micellar microstructure. The content of casein monomer and minerals in yak casein micelles was studied by high performance liquid chromatography and ion chromatography. The animo sequence and spatial structures of four main monomer caseins in micelles will be determined by time of flight mass spectrometry, fourier transform infrared spectroscopy and circular dichroism. The internal structure and the size, distrubution of calcium phosphate in casein micelles will be studied by small angle X-ray scattering and small angle neutron scattering. The interaction between casein monomers will be analyzed using surface plasmon resonance and atomic force microscopy technology. The formation mechanism of the casein micellar microstructure will be clarified on the base of casein micellar structure models and the microstructure control parameters of casein micellar will be achieved. The results would guide the modification of the microstructure of casein micelles. It would also contribute to the development of casein products with higher quality, and promoting Tibetan economy and income of Tibetan herders.