title: The ultrastructure of type I collagen at nanoscale: large or small D-spacing distribution?
abstract: D-Spacing is the most significant topographic feature of type I collagen fibril, and it is important for our understanding of the structure and function in collagens. Traditionally, the D-spacing of type I collagen fibril was shown to have a singular value of 67 nm, but recent works indicated that the D-spacing values have a large distribution of up to 10 nm when measured by atomic force microscopy. We found that this large distribution of D-spacing values mainly resulted from image drift during measurement. Note that the D-spacing was homogeneous in a single type I collagen fibril. Our statistical analysis indicated that the D-spacing values of type I collagen fibrils exhibited only a narrow distribution of 2.5 nm around the value of 67 nm. In addition, the D-spacing values of the collagen fibrils were nearly identical not only within a single fibril bundle, but also in different fibril bundles. The measurement of the D-spacing values of collagen may provide important structural information in many research areas such as collagen related diseases, construction of molecular model of collagen, and collagen fibrogenesis.
authors.affiliation: State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, China. xbb@sdu.edu.cn.
authors.forename: Hai-Nan
authors.initials: HN
authors.lastname: Su
authors.forename: Li-Yuan
authors.initials: LY
authors.lastname: Ran
authors.forename: Zhi-Hua
authors.initials: ZH
authors.lastname: Chen
authors.forename: Qi-Long
authors.initials: QL
authors.lastname: Qin
authors.forename: Mei
authors.initials: M
authors.lastname: Shi
authors.forename: Xiao-Yan
authors.initials: XY
authors.lastname: Song
authors.forename: Xiu-Lan
authors.initials: XL
authors.lastname: Chen
authors.forename: Yu-Zhong
authors.initials: YZ
authors.lastname: Zhang
authors.forename: Bin-Bin
authors.initials: BB
authors.lastname: Xie
mesh_terms: D024042:Collagen Type I / Q000737:chemistry* / Q000648:ultrastructure; D018625:Microscopy, Atomic Force; D049329:Nanostructures / Q000737:chemistry; D010316:Particle Size
chemical_list: D024042:Collagen Type I