Verification of Okuyama model for native collagen based on X-ray diffraction pattern obtained by synchrotron radiation

本研究的目的是利用同步辐射获得的连续衍射来验证胶原蛋白的Okuyama模型。不幸的是，在这个研究学期的最后一年，我们只有两次机会使用同步加速器设备。因此，许多要做的事情还没有完成。目前得到的结果如下：(1)与大鼠尾腱相比，大部分袋鼠（或小袋鼠）尾腱标本具有良好的取向性和结晶度。(2)由于天然胶原蛋白的衍射斑大多很宽，而且弥散，所以不能采用纤维衍射领域常用的背景减法。我们发现，在胶原蛋白衍射图较宽的情况下，用傅里叶-贝塞尔函数进行二维背景减法是最好的方法。(3)由于我们只有在最后一年才能使用同步加速器设备，我们无法在研究期限内完成这个研究项目。然而，从同步辐射拍摄的x射线衍射图来看，我们可以定性地说，胶原蛋白的Okuyama模型可以像Rich & Crick模型一样解释天然胶原的x射线衍射图。我们将继续这个研究项目，完成定量分析。

The aim of this research project is to verify Okuyama model for collagen by using continuous diffraction obtained by synchrotron radiation. Unfortunately, we had only two chances to use synchrotron facility in the last year of this research term. Therefore, many of the things to do are not yet finished. The following results were obtained so far.(1) It was found that most of the specimens from kangaroo (or wallaby)-tail-tendon have a good orientation and good crystallinity k compared with those from rat-tail-tendon.(2) Since most of the diffraction spots from native collagen are very broad and diffuse, it is not possible to use background subtraction method usually used in the fiber diffraction field. We found that two-dimensional background subtraction by Fourier-Bessel function is the best method in the case of broad diffraction pattern from collagen.(3) Since we could use synchrotron facility only in the final year, we could not finish this research project within the research term. However, from the X-ray diffraction pattern taken by synchrotron radiation, we could say qualitatively that the Okuyama model for collagen could explain X-ray diffraction pattern from native collagen just as the Rich ＆ Crick model could. We will continue this research project to finish a quantitative analysis.