Viscoelastic and light scattering studies on thermally induced sol to gel phase transition in fish myosin solutions.
Viscoelastic and light scattering studies on thermally induced sol to gel phase transition in fish myosin solutions.
复制标题
鱼肌球蛋白溶液中热诱导溶胶到凝胶相变的粘弹性和光散射研究。
DOI：
10.1002/bip.10388
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发表时间：
2003
期刊：
影响因子：
2.9
通讯作者：
T. Dobashi
中科院分区：
文献类型：
--
作者：
Sawa Kouchi;S. Kondo;K. Ooi;H. Ichikawa;T. Dobashi
在0.6M KCl和pH 7.0条件下，对鱼（白花鱼）肌球蛋白溶液进行粘弹性（VE）和动态光散射（DLS）分析，分别为30 mg/mL和0.1 mg/mL。剪切模量G在25℃以下保持不变，在30℃孵育下增大，随着孵育温度的降低，G进一步增大。不同时间进程的G / T曲线在升温过程中在35℃左右出现尖峰，在60℃左右出现平缓峰；而在冷却过程中，当温度升高到不超过60℃时，G在30℃左右逐渐增加，一旦样品温度超过60℃，G的绝对值强烈依赖于最高升高温度和在该温度下的孵育时间。在每个时间过程中，观察了相应的粘度eta的行为。在此基础上，从头部和尾部的S-S桥形成和尾部螺旋状α螺旋的解绕/复绕的角度讨论了肌球蛋白溶液热诱导凝胶化的机制。
Viscoelastic (VE) and dynamic light scattering (DLS) analyses of fish (white croaker) myosin solutions were performed at myosin concentrations of 30 mg/mL for VE and 0.1 mg/mL for DLS at 0.6M KCl and pH 7.0 to clarify thermally induced gelation. The hydrodynamic radius R(h) considerably decreased around 30-35 degrees C. The shear modulus G was constant below 25 degrees C and increased by incubating the sample at 30 degrees C. G further increased as the temperature of the incubated sample decreased. The curves of G vs T for different time courses showed a sharp peak around 35 degrees C and a moderate peak around 60 degrees C in the heating process, while a stepwise increase in G was observed around 30 degrees C in the cooling process when the temperature was elevated to not more than 60 degrees C. No distinct stepwise change was observed once the temperature of the sample exceeded 60 degrees C. The absolute value of G strongly depended on the maximum elevated temperature and the incubation time at that temperature. The corresponding behavior of the viscosity eta was observed for each time course. Based on these results, the mechanism of thermally induced gelation of myosin solutions is discussed in view of S-S bridge formation in the head and tail portions and unwinding/rewinding of coiled-coil alpha-helices in the tail portion.