Piez K A, Trus B L
Biosci Rep. 1981 Oct;1(10):801-10. doi: 10.1007/BF01114803.
A specific fibril model is presented consisting of bundles of five-stranded microfibrils, which are usually disordered (except axially) but under lateral compression become ordered. The features are as follows (where D = 234 residues or 67 nm): (1) D-staggered collagen molecules 4.5 D long in the helical microfibril have a left-handed supercoil with a pitch of 400-700 residues, but microfibrils need not have helical symmetry. (2) straight-tilted 0.5-D overlap regions on a near-hexagonal lattice contribute the discrete x-ray diffraction reflections arising from lateral order, while the gap regions remain disordered. (3) The overlap regions are equivalent, but are crystallographically distinguished by systematic displacements from the near-hexagonal lattice. (4) The unit cell is the same as in a recently proposed three-dimensional crystal model, and calculated intensities in the equatorial region of the x-ray diffraction pattern agree with observed values.
提出了一种特定的原纤维模型，它由五股微原纤维束组成，这些微原纤维通常是无序的（轴向除外），但在侧向压缩下会变得有序。其特征如下（其中D = 234个残基或67纳米）：（1）在螺旋微原纤维中4.5D长的D型交错排列的胶原分子具有左手超螺旋，螺距为400 - 700个残基，但微原纤维不一定具有螺旋对称性。（2）近六边形晶格上的直倾斜0.5D重叠区域产生由侧向有序引起的离散X射线衍射反射，而间隙区域保持无序。（3）重叠区域是等效的，但通过与近六边形晶格的系统位移在晶体学上得以区分。（4）晶胞与最近提出的三维晶体模型中的相同，并且X射线衍射图案赤道区域的计算强度与观测值一致。
