Characterization of the emulsification properties of 2S albumins from sunflower seed
Characterization of the emulsification properties of 2S albumins from sunflower seed
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DOI：
10.1006/jcis.2001.8093
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发表时间：
2002-03-01
影响因子：
9.9
通讯作者：
Shewry, PR
中科院分区：
文献类型：
--
作者：
Burnett, GR;Rigby, NM;Shewry, PR
已经研究了来自向日葵种子的2S白蛋白稳定水包油乳液的能力，证明其中一种蛋白质（SFA8）有效地稳定乳液，而另一种蛋白质（SF-LTP）不稳定乳液。测量这两种蛋白质的表面张力和表面膨胀粘度，根据其在界面处形成强弹性单层的能力来合理化SFA8的乳化能力。通过荧光、圆二色性（CD）和傅里叶变换红外（FT-IR）光谱研究了SFA8吸附到油/水界面后发生的二级结构变化。发现蛋白质的β-折叠含量在吸附后以α-螺旋和随机结构为代价增加。此外，FT-IR测量表明在吸附时存在分子间β-折叠形成。用油溶性荧光猝灭剂的荧光研究表明，SFA8中存在的单个色氨酸残基可能位于乳液的油相中。这个残基被认为是部分埋在天然蛋白质，这些数据表明，在这个残基侧翼的多肽区域的变化可能发挥重要作用的分子重排发生或吸附后的油/水界面。(C)2002年爱思唯尔科学（美国）。
The ability of 2S albumins from sunflower seeds to stabilize oil-in-water emulsions has been investigated, demonstrating that one of the proteins (SFA8) effectively stabilizes emulsions, while another (SF-LTP) does not stabilize emulsions. The surface tension and surface dilation viscosity of these two proteins were measured, rationalizing the emulsifying ability of SFA8 in terms of its ability to form a strongly elastic monolayer at interfaces. The secondary structure changes that occur upon adsorption of SFA8 to the oil/water interface have also been studied by fluorescence, circular dichroism (CD), and Fourier-transform infrared (FT-IR) spectroscopy. It was found that the beta-sheet content of the protein increased upon adsorption at the expense of alpha-helix and random structure. Moreover, FT-IR measurements indicate the presence of intermolecular beta-sheet formation upon adsorption. Fluorescence studies with an oil-soluble fluorescence quencher indicate that the single tryptophan residue present in SFA8 may become located in the oil-phase of the emulsion. This residue is thought to be partially buried in the native protein, and these data suggest that changes in the polypeptide region flanking this residue may play an important role in the molecular rearrangement that occur on or following adsorption to the oil/water interface. (C) 2002 Elsevier science (USA).