Sulfate dodecyl sodium-induced stability of a model intrinsically disordered protein, bovine casein
Sulfate dodecyl sodium-induced stability of a model intrinsically disordered protein, bovine casein
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硫酸十二烷基钠诱导的模型固有无序蛋白质（牛酪蛋白）的稳定性
DOI：
10.1016/j.foodhyd.2018.03.043
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发表时间：
2018-09
影响因子：
10.7
通讯作者：
Cristiano L.P. Oliveira
中科院分区：
文献类型：
--
作者：
Yang Sun;Juntao Zhang;Haibo Wang;Tingting Wang;Hua Cheng;Bo Yu;Cristiano L.P. Oliveira
酪蛋白具有众所周知的营养特性，占牛奶中蛋白质含量的80%左右，被归类为高度内在无序蛋白（IDP）。本文采用多种技术研究了硫酸盐十二烷基钠（SDS）诱导牛酪蛋白的构象变化。采用等温滴定量热法（ITC）和差示扫描量热法（DSC）测定了形成的配合物的构象变化和热稳定性。光谱结果表明，在SDS的临界胶束浓度以上，酪蛋白呈现出更高的螺旋含量，但三级结构的损失，即所谓的熔融球状状态。根据远紫外CD，即使在70 °C时，SDS也可以阻止酪蛋白的热自结合。酪蛋白的1h NMR谱显示1.0 ppm附近α-氢区共振向高场偏移，5.5 ~ 8.0 ppm附近芳香区共振向低场偏移，而酪蛋白的NOESY谱在SDS的结合下几乎没有发生化学偏移。结合动态光散射（DLS）、扫描电镜（SEM）和小角度x射线散射（SAXS）的结果，可以得到酪蛋白胶束呈现直径为~ 800 nm的椭圆形状，与SDS结合后，酪蛋白胶束解离成直径为10 nm的更致密的球状颗粒，其核壳结构由SDS分子和酪蛋白组成。本研究不仅为sds诱导酪蛋白稳定的分子机制提供了新的见解，而且有助于了解表面活性剂在食品工业中对牛酪蛋白结构-功能关系的作用。
With well-known nutritional properties, casein contributes to about 80% of protein content in milk and has been classified as highly intrinsically disordered protein (IDP). In this paper, the sulfate dodecyl sodium (SDS)-induced conformational changes of bovine casein were studied by multi-techniques. Isothermal titration calorimetry (ITC) and differential scanning calorimetry (DSC) were used to obtain the stoichiometry of conformational changes and the thermal stability of the formed complexes. Spectral results indicated that casein presented a higher helical content but loss of tertiary structure above critical micelle concentration of SDS, namely, the so-called molten globule like state. The thermal self-association of casein could be prevented by SDS according to far-UV CD even at 70 °C. The1H NMR spectrum of casein showed that the resonance around 1.0 ppm, the region of α-hydrogen, shifted to the higher field, and the aromatic region around 5.5–8.0 ppm shifted to the lower field, while the NOESY spectra of casein exhibited few chemical shifts with binding of SDS. Combining the results of dynamic light scattering (DLS), scanning electron microscope (SEM) and small angle x-ray scattering (SAXS), one obtains that casein micelles presented an elliptical shape of ∼800 nm in diameter and upon binding with SDS, the casein micelles disassociated into more compact globular particles of 10 nm in diameter with a core-shell structure composed by SDS molecules and casein proteins. The present work, not only provides molecular insights into the mechanism of SDS-induced stability of a model IDP, casein, but also helps understand the role of surfactants on the structure–function relationship of bovine casein in the food industry.
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影响因子：
3.9
作者：
T. F. Kumosinski;H. Pessen;H. M. Farrell;H. Brumberger
通讯作者：
T. F. Kumosinski;H. Pessen;H. M. Farrell;H. Brumberger
DOI：
10.1016/s0021-9258(19)34083-9
发表时间：
1990-03
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
A. Shrake;P. Ross
通讯作者：
A. Shrake;P. Ross
影响因子：
2.1
作者：
M. L. Green
通讯作者：
M. L. Green
影响因子：
1.7
作者：
T. Ishida;Yukiko Toda;M. Tarui;M. Doi;M. Inoue
通讯作者：
T. Ishida;Yukiko Toda;M. Tarui;M. Doi;M. Inoue
影响因子：
9.9
作者：
Otzen, Daniel E.;Sehgal, Pankaj;Westh, Peter
通讯作者：
Westh, Peter