鹰嘴豆分离蛋白质的特性

Characteristics of Chickpea Protein Isolates

研究了鹰嘴豆分离蛋白质质量、功能性质、物理化学性质及结构特征.氨基酸分析表明,鹰嘴豆蛋白含有所有必需氨基酸,与FAO/WHO模式相比,色氨酸是其第一限制性氨基酸,蛋白质的化学评分为71分.表面荧光探针ANS法测得的表面疏水性为94.3.DSC热分析显示该蛋白质含有两个热变性温度,分别为83.7℃和95.7℃.圆二色谱(CD)分析了鹰嘴豆分离蛋白的二级结构:α-螺旋36.2%,β-折叠28.4%,转角10.3%,无规卷曲25.2%.经凝胶过滤色谱SephacrylS-200分离纯化得到7个不同相对分子质量蛋白质组分,其中两个主要组分的相对分子质量为170000及110000.

Protein quality, functional properties, physicochemical characteristics and structure parameters of the chickpea protein isolates were investigated. Amino acid analysis showed that the protein contained all essential amino acids. In relation to FAO/WHO reference pattern, tryptophan was the first limiting amino acid, and the chemical score of the protein was 71. 0. Surface hydrophobicity index 94. 3 was determined by fluorescence probe 1-anilino-8-naphthalene sulfonate (ANS). Differential Scanning Calorimetry (DSC) showed the thermal denaturation temperatures of chickpea protein were at 83. 7℃ and 95. 7℃, respectively. The secondary structure analyzed by circular dichroism (CD) showed that, α-helix, β-sheet, turn and random coil were 36. 2%, 28. 4%, 10. 3% and 25. 2%, respectively. Chickpea protein isolates were fractionated into seven fractions with different molecular weights by gel filtration on Sephacryl S-200, and the two major fractions' molecular weights were 170 000 and 110 000, respectively.