New insight into the solution structures of wheat gluten proteins from Raman optical activity
New insight into the solution structures of wheat gluten proteins from Raman optical activity
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DOI：
10.1021/bi027059y
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发表时间：
2003-05-20
期刊：
影响因子：
2.9
通讯作者：
Barron, LD
中科院分区：
文献类型：
--
作者：
Blanch, EW;Kasarda, DD;Barron, LD
测定了小麦蛋白a-麦胶蛋白（a-麦胶蛋白）、omega-麦胶蛋白和来自高分子量谷蛋白亚基（hw - gs） Dx5的30 kDa肽T-A-1的振动拉曼光学活性（ROA）光谱，以获得其溶液结构的新信息。光谱数据表明，在所研究的条件下，a-麦胶蛋白含有相当数量的水合α -螺旋，其中大部分可能位于相对结构化的c端结构域内。少量的β -结构和聚（l -脯氨酸）II （PPII）螺旋也被鉴定出来。发现甲醇的加入增加了α -螺旋的含量，但牺牲了一些β和PPII结构。相比之下，发现omega-麦胶蛋白和T-A-1肽由大量明确的PPII结构组成，有一些旋转，但没有α -螺旋。T-A-1肽的结果与HMW-GS扩展但不高度刚性的模型一致。基于主成分分析（PCA）的模式识别技术对ROA谱的应用强化了这些结论。
Vibrational Raman optical activity (ROA) spectra of the wheat proteins a-gliadin (A-gliadin), omega-liadin, and a 30 kDa peptide called T-A-1 from the high molecular weight glutenin subunit (HMW-GS) Dx5 were measured to obtain new information about their solution structures. The spectral data show that, under the conditions investigated, A-gliadin contains a considerable amount of hydrated alpha-helix, most of which probably lies within a relatively structured C-terminal domain. Smaller quantities of beta-structure and poly(L-proline) II (PPII) helix were also identified. Addition of methanol was found to increase the alpha-helix content at the expense of some of the beta and PPII structure. In comparison, omega-gliadin and the T-A-1 peptide were found to consist of large amounts of well-defined PPII structure with some turns but no alpha-helix. The results for the T-A-1 peptide are in agreement with a model in which HMW-GS are extended but not highly rigid. Application of a pattern recognition technique, based on principal component analysis (PCA), to the ROA spectra reinforces these conclusions.