A study of alcohol-induced gelation of beta-lactoglobulin with small-angle neutron scattering, neutron spin echo, and dynamic light scattering measurements.
A study of alcohol-induced gelation of beta-lactoglobulin with small-angle neutron scattering, neutron spin echo, and dynamic light scattering measurements.
复制标题
利用小角中子散射、中子自旋回波和动态光散射测量研究酒精诱导的 β-乳球蛋白凝胶化。
DOI：
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
M. Shibayama
中科院分区：
文献类型：
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作者：
K. Yoshida;T. Yamaguchi;N. Osaka;H. Endo;M. Shibayama
采用小角中子散射（SANS）、中子自旋回波（NSE）和时间分辨动态光散射（TRDLS）测量方法研究了β -乳球蛋白（β - lg）在0.1 M （M = mol L(-1)）盐酸溶液中的凝胶化。在酒精-水溶液中，β - lg在特定的酒精浓度下发生凝胶化，此时酒精诱导的β - lg的α螺旋结构是稳定的。SANS谱显示β - lg在低酒精浓度下以单分子形式存在。随着酒精浓度的增加，当样品凝胶化时，谱图显示出约为1.7的幂律行为。在所有使用的醇-水混合物中都观察到这些行为，但是随着醇的疏水性基团大小的增加，SANS谱变化的醇浓度向较低的醇浓度区域转移。由NSE的中间散射函数（ISF）和TRDLS的强度时间相关函数（ITCF）得到的表观扩散常数主要取决于凝胶化前醇水混合物的粘度。凝胶化后，凝胶的isf在NSE时间尺度范围内没有明显变化，说明β - lg凝胶具有微观刚性结构。凝胶化前ITCF函数呈双指数衰减型，凝胶化后ITCF函数呈对数衰减型（指数α = 0.7）。在pH = 7时，酒精诱导的凝胶形成的机制很可能与热诱导的凝胶形成的机制相似，在热诱导的凝胶中，β - lg聚集体粘在一起形成一个分形网络，尽管前者的凝胶形成时间比后者快。
Gelation of beta-lactoglobulin (beta-Lg) in various alcohol-water mixtures with 0.1 M (M = mol L(-1)) hydrochloric acid was investigated with small-angle neutron scattering (SANS), neutron spin echo (NSE), and time-resolved dynamic light scattering (TRDLS) measurements. The beta-Lg in alcohol-water solutions undergoes gelation at specific alcohol concentrations where the alcohol-induced alpha-helical structure of beta-Lg is stabilized. The SANS profiles showed that beta-Lg exists as a single molecule at a low alcohol concentration. With increasing alcohol concentration, the profiles indicate a power law behavior of approximately 1.7 when the samples gelate. These behaviors were observed in all alcohol-water mixtures used, but the alcohol concentrations where the SANS profiles change shift to a lower alcohol concentration region with an increase in the size of the hydrophobic group of the alcohols. Apparent diffusion constants, obtained from the intermediate scattering function (ISF) of NSE and the intensity time correlation function (ITCF) of TRDLS, mainly depend on the viscosity of alcohol-water mixtures before gelation. After gelation, on the other hand, the ISFs of gels do not change appreciably in the range of the NSE time scale, indicating the microscopically rigid structure of beta-Lg gel. The ITCF functions obtained from TRDLS follow a double exponential decay type before gelation, but a logarithmic one (exponent alpha = 0.7) after gelation. It is most likely that the alcohol-induced gelation undergoes a similar mechanism to that for the heat-induced one at pH = 7 where beta-Lg aggregates stick together to form a fractal network, although the gelation time is faster in the former than in the latter.
影响因子：
15
作者：
Lyon, RP;Atkins, WM
通讯作者：
Atkins, WM