Size distribution of pressure-decomposed casein micelles studied by dynamic light scattering and AFM
Size distribution of pressure-decomposed casein micelles studied by dynamic light scattering and AFM
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通过动态光散射和 AFM 研究压力分解酪蛋白胶束的尺寸分布
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
U. Kulozik
中科院分区：
文献类型：
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作者：
R. Gebhardt;W. Doster;J. Friedrich;U. Kulozik
利用原位光散射技术和非原位原子力显微镜研究了酪蛋白胶束的可逆和不可逆状态。在环境压力下进行的AFM实验揭示了整个胶束的异质性，这表明在20 nm尺度上的子结构。在50和250 MPa之间的压力下，天然胶束在所观察到的子结构的尺度上分解成小片段。在高于300 MPa的压力下，胶束完全分解成它们的单体成分。在压力释放后，根据所施加的初始压力，观察到两个离散的酪蛋白聚集体群体：在160和240 MPa之间，形成直径接近100 nm的稳定胶束，没有可检测的亚结构。暴露于高于280 MPa的压力的酪蛋白胶束在环境压力下重新缔合，产生直径接近25 nm的微型胶束。结构模型的影响进行了讨论。
Reversible and irreversible states of pressure-dissociated casein micelles were studied by in situ light scattering techniques and ex situ atomic force microscopy. AFM experiments performed at ambient pressure reveal heterogeneities across the micelle, suggesting a sub-structure on a 20 nm scale. At pressures between 50 and 250 MPa, the native micelles disintegrate into small fragments on the scale of the observed sub-structure. At pressures above 300 MPa the micelles fully decompose into their monomeric constituents. After pressure release two discrete populations of casein aggregates are observed, depending on the applied initial pressure: Between 160 and 240 MPa stable micelles with diameters near 100 nm without detectable sub-structures are formed. Casein micelles exposed to pressures above 280 MPa re-associate at ambient pressure yielding mini-micelles with diameters near 25 nm. The implications concerning structural models are discussed.