Protein structural segments and their interconnections derived from optical spectra. Thermal unfolding of ribonuclease T1 as an example.
Protein structural segments and their interconnections derived from optical spectra. Thermal unfolding of ribonuclease T1 as an example.
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来自光谱的蛋白质结构片段及其互连。
DOI：
10.1021/bi961178u
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Keiderling,TA
中科院分区：
文献类型：
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作者：
Pancoska,P;Fabian,H;Yoder,G;Baumruk,V;Keiderling,TA
本文研究了一种新的蛋白质结构描述符，它超越了对几种构象类型的平均分数组分(FC)的预测，并表示了连续的、定义明确的二级结构元件(如α-螺旋和β-Sheet)的数量和相互连接。可以使用神经网络方法从光谱中预测该矩阵描述符。新的矩阵加上传统的Fc描述符可以快速和一般地获得，以提供以前从光学光谱中得不到的细节水平，以及仅使用Fc描述符来区分原本可能被视为非常相似的蛋白质。作为其潜在应用的一个例子，该矩阵描述符方法被用于分析核糖核酸酶T1在水中的天然状态和可逆热变性。对傅立叶变换红外光谱数据的分析表明，在50−55°C时，主要螺旋段的初始损失，但随之而来的是片段数或片层FC值几乎没有变化。圆二色谱(CD)和振动CD数据也被用来支持这种基于FC随温度变化的解释。对该蛋白质在D2O中的相应数据的平行分析表明，该方法对用于制备未知样本的H−D交换程度与参考数据集之间的匹配很敏感。
A novel descriptor for protein structure is examined here that goes beyond predictions of the average fractional components (FC) of a few conformational types and represents the number and interconnection of segments of continuous, well-defined secondary structural elements such as α-helices and β-sheets. This matrix descriptor can be predicted from optical spectra using neural network methods. The new matrix plus traditional FC descriptors can be quickly and generally obtained to provide a level of detail not previously derived from optical spectra and a discrimination between proteins that might otherwise be viewed as being very similar using just the FC descriptor. As an example of its potential utilization, this matrix descriptor approach was applied to an analysis of both the native state and the reversible thermal denaturation of ribonuclease T1in H2O. Analyses of the FTIR spectral data indicate initial loss of the major helical segment at 50−55 °C but with little accompanying change in the number of sheet segments or the sheet FC values. Circular dichroism (CD) and vibrational CD data are also used to support this interpretation based on FC changes with temperature. Parallel analysis of the corresponding data for this protein in D2O demonstrates that the method is sensitive to the match between the degree of H−D exchange used to prepare samples for the unknown and the reference data set.