南方水牛奶酪蛋白及大豆蛋白肽指纹图谱的差异性  

Difference in Peptide Mass Fingerprinting Between South Buffalo Milk Casein and Soybean Protein

作　　者：徐明芳[1] 戴金凤[1] 向明霞[1] 成希飞[1] 曾晓琮 万丛庆 周卫军[1] 

机构地区：[1]暨南大学生命科学技术学院,广东广州510632

出　　处：《华南理工大学学报（自然科学版）》2014年第6期136-144,共9页Journal of South China University of Technology(Natural Science Edition)

基　　金：广东省科技计划项目(2009B011300003)

摘　　要：通过LTQ Orbitrap XL组合型傅里叶变换高分辨质谱与反相高效液相色谱技术联用建立了南方水牛奶酪蛋白和大豆蛋白主要组分肽质指纹图谱，并对其氨基酸组成与序列进行了比较．结果表明：酪蛋白经胰蛋白酶酶解后得到的28个肽段中没有检测到与酶解大豆分离蛋白181个肽段相匹配的肽段；酪蛋白（CN）的主要组分是仅αs1-CN、β-CN、κ-CN，大豆蛋白的主要组分为大豆球蛋白（包括大豆球蛋白Gl～G5亚基）和／3伴大豆球蛋白（α，α′，β 链）；水牛奶酪蛋白和大豆蛋白在亚基组分的氨基酸数量、组成比例和排列方式均呈现出明显的差异，大豆蛋白的各组分亚基的氨基酸全序列均大于酪蛋白各组分的氨基酸全序列，且大豆蛋白各组分的分子质量均显著高于酪蛋白各组分．LTQOr-bitrap XL质谱技术对乳源蛋白肽质指纹的分析，为今后鉴定分析牛奶蛋白中是否添加廉价蛋白提供了高精度和高准确度的检测方法，也为复杂混合物中的痕量组分检测提供了理论依据．Peptide mass fingerpringting spectra of south buffalo milk casein and soybean protein were established by using a LTQ Orbitrap XL mass spectrometer combined with RP-HPLC techniques, and the corresponding amino acid sequences were compared. The results indicate that, among the 28 detected peptides fractions obtained by the tryptic hydrolysis of αs1-CN、β-CN and κ-CN originated from south buffalo milk caseins, no fraction matches with the 181 peptides fractions from the glycinin （glycinin G1 -G5 subunit） and the β-conglycinin （α,α′,β subunit） of soybean protein components. Moreover, it is found that there exists great differences in the number, composition ratio and arrangement patterns of amino acid subunits between south buffalo milk caseins and soybean protein compo- nents, and that the full amino acid sequence of soy protein subunits is longer than that of casein amino acid components, the molecular mass of each component of soy protein is significantly higher than that of the components of casein. The adopted LTQ Orbitrap XL mass spectrometry technique for analyzing the peptide mass fingerprint of milkderived protein provides a high-precision tool for identifying cheap proteins in milk protein and lays a reliable theoretical foundation for the detection of trace components in complex mixture.

关 键 词：水牛奶酪蛋白 大豆蛋白 LTQ ORBITRAP XL 肽指纹图谱 氨基酸序列 

分 类 号：Q503[生物学—生物化学]