双峰驼驼乳中血清白蛋白的分离纯化及其结构表征

本文以双峰驼驼乳为原料,通过DEAE-FF离子交换层析和Sephacryl S-100凝胶过滤层析对驼乳中血清白蛋白(Camel serum albumin,CSA)进行分离纯化,并对其氨基酸序列、相对分子质量、等电点、氨基酸组成及二级结构进行研究。结果表明:纯化后CSA纯度大于95%;与野骆驼CSA氨基酸序列覆盖率达89%;分子量为66490.17 Da;等电点pI为4.48;氨基酸组成中谷氨酸含量最高,含量为12.41%,必需氨基酸含量为47.36%,经计算其必需氨基酸模式与人体必需氨基酸的要求较接近,是一类优质的动物蛋白质资源;高α-螺旋含量,低β-折叠和无规则卷曲是CSA的主要结构特征。

Purification and Structural Characterization of Serum Albumin in Bactrian Camel Milk

In this study, the camel serum albumin (CSA) of bactrian camel milk were isolated and purified by DEAE-FF chromatography and Sephacryl S-100 gel filtration, and then amino acid sequence, absolute molecular weight, isoelectric point, amino acid composition and secondary structure of CSA were investigated. The results showed that the purity of CSA was greater than 95% after two steps of purification. Compared with the Camelus ferus SA sequence from the NCBI database (NCBI:XP_006188754), the sequence coverage of CSA was 89%. Its isoelectric point was 4.48 by IEF and the relative molecular mass was 66490.17 Da. CSA contained a full range of amino acid, and essential amino acids accounted for 47.36% of the total amino acids. The most abundant amino acid was glutamic acid, accounting for 12.41% of the total amino acids. The model of total essential amino acids was close to the human body essential amino acid requirements, and CSA was considered to a kind of valuable animal protein resource.High alpha helix content, low beta fold and irregular curl were the main structural characteristics of the CSA.