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Verification of Okuyama Model for Collagen based on Single Crystal Analyses of Model Peptides at High Resolution

基于高分辨率模型肽单晶分析验证胶原蛋白奥山模型

基本信息

批准号：
16550107
负责人：
OKUYAMA Kenji
金额：
$ 2.3万
依托单位：
Osaka University (2005-2006)Tokyo University of Agriculture and Technology (2004)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16550107/
关键词：
collagen triple helix model peptide single crystal crystal analysis host-guest peptide 三重らせん構造

项目摘要

The Rich and Crick model is widely accepted as the molecular structure of collagen during the last five decades. This model was derived from the fiber diffraction data of native collagen and is made up of a triple helical structure in which each peptide strand forms a right-handed 10/1-helical conformation and a pitch length of 85.8 Å. This triple-helical structure can be considered to be a single left-handed 10/3-helix with 28.6 Å axial repeat.On the other hand, we found a left-handed 7/2-helical conformation with 20 Å axial repeat in the single crystal structure of a collagen-model peptide. Since this structure could explain key features of the diffraction patterns from native collagen, we proposed it as a new structural model for collagen (1977). Unfortunately, however, this model has not been acknowledged as a structural model for collagen, but has instead been regarded only as a structure for a collagen-like peptide. Recently, we demonstrated that the both 10/3-and 7/2-helical models could explain X-ray fiber diffraction data from native collagen quantitatively. The aim of the present research is the verification of our 7/2-helical model based on the single crystal structures of collagen model peptides at high resolution.In this study, we have analyzed a total of 14 model peptides at high resolution by using synchrotron radiation. All of these molecular conformations were found to be very close to that of the ideal 7/2-helical model. More than 20 triple helical conformations of collagen model peptides with various sequences have been analyzed in the several groups in the world including our group. All of them support our 7/2-helical model and there is no such supporting data for the Rich and Crick model, which indicated strongly that an average conformation of native collagen is the 7/2-helical structure rather than the now prevailing 10/3-helical model.

在过去的五十年里，Rich和Crick模型被广泛接受为胶原蛋白的分子结构。该模型来源于天然胶原的纤维衍射数据，由三螺旋结构组成，其中每条肽链形成右旋10/1螺旋构象和85.8 π的螺距长度。该三螺旋结构可以被认为是一个单一的左旋10/3-螺旋，28.6个重复的轴向重复，另一方面，我们发现了一个左旋7/2-螺旋构象，20个重复的轴向重复的胶原蛋白模型肽的单晶结构。由于这种结构可以解释天然胶原蛋白衍射图案的关键特征，我们提出将其作为胶原蛋白的新结构模型（1977）。然而，不幸的是，该模型尚未被承认为胶原蛋白的结构模型，而是仅被认为是胶原蛋白样肽的结构。最近，我们证明了10/3-和7/2-螺旋模型可以定量地解释天然胶原的X射线纤维衍射数据。本研究的目的是验证我们的7/2-螺旋模型的基础上的单晶结构的胶原蛋白模型肽在高分辨率。在这项研究中，我们已经分析了共14个模型肽的高分辨率使用同步辐射。所有这些分子构象被发现是非常接近的理想7/2螺旋模型。包括本课题组在内的国际上多个研究组已分析了20多种不同序列的胶原蛋白模型肽的三螺旋构象。所有这些都支持我们的7/2-螺旋模型，而Rich和Crick模型没有这样的支持数据，这强烈表明天然胶原蛋白的平均构象是7/2-螺旋结构，而不是现在流行的10/3-螺旋模型。