Conformation Change of Hornet Silk Proteins in the Solid Phase in Response to External Stimulation
Conformation Change of Hornet Silk Proteins in the Solid Phase in Response to External Stimulation
复制标题
大黄蜂丝蛋白固相响应外部刺激的构象变化
DOI：
10.1002/chir.22824
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发表时间：
2018
期刊：
影响因子：
2
通讯作者：
Kuroda R. Kaneda T.
中科院分区：
文献类型：
--
作者：
Takahashi H;Abe M;Kuroda R;Kuroda R. Kaneda T.
根据制备方法的不同，大黄蜂的丝可以呈现纤维、海绵、薄膜和凝胶等多种形态。我们研究了大黄蜂丝蛋白（胡蜂）作为再生膜的构象变化，使用手性分光光度计通用手性分光光度计1，它可以测量真正的圆二色谱，而没有固态样品固有的伪影信号。光谱显示，膜中的蛋白质响应于热/湿处理而迅速改变构象，从α-螺旋到卷曲螺旋，然后到β-折叠结构，但是当样品浸泡在EtOH/水溶液中时，转变停止在卷曲螺旋状态。α螺旋向卷曲螺旋的转变需要水，进一步转变为β折叠结构需要额外的能量。这是第一个成功的圆二色性研究的原纤维丝蛋白，以遵循构象的变化，在固态。这项工作表明，即使在固相中，蛋白质也可以很容易地响应外部刺激而发生构象变化，这可以通过固相可行的手性光学速率计来追踪。将非自然应力应用于蛋白质，可以对其结构和特性提供有价值的见解。
Hornet silks adopt a variety of morphology such as fibers, sponge, films, and gels depending on the preparation methods. We have studied the conformation change of hornet silk proteins (Vespa mandarina) as regenerated films, using chiroptical spectrophotometer universal chiroptical spectrophotometer 1, which can measure true circular dichroism spectra without artifact signals that are intrinsic to solid‐state samples. The spectra showed that the proteins in films alter the conformation rapidly from the α‐helix to the coiled coil and then to a β‐sheet structure in response to heat/moisture treatment, but the transformation stopped at the coiled coil state when the sample was soaked in EtOH/water solution. Water is required for the α‐helix to the coiled coil transition, and extra energy is required for the further transition to a β‐sheet structure. This is the first successful circular dichroism study of fibril silk proteins to follow the conformation changes in the solid state. This work shows that proteins can undergo conformational changes easily even in the solid phase in response to external stimuli, and this can be traced by solid‐phase‐feasible chiroptical spectrophotometers. Application of unnatural stress to proteins gives valuable insights into their structure and characteristics.