Lateral packing of mineral crystals in bone collagen fibrils.
Combined small-angle x-ray scattering and transmission electron microscopy studies of intramuscular fish bone (shad and herring) indicate that the lateral packing of nanoscale calcium-phosphate crystals in collagen fibrils can be represented by irregular stacks of platelet-shaped crystals, intercalated with organic layers of collagen molecules. The scattering intensity distribution in this system can be described by a modified Zernike-Prins model, taking preferred orientation effects into account. Using the model, the diffuse fan-shaped small-angle x-ray scattering intensity profile, dominating the equatorial region of the scattering pattern, could be quantitatively analyzed as a function of the degree of mineralization. The mineral platelets were found to be very thin (1.5 nm approximately 2.0 nm), having a narrow thickness distribution. The thickness of the organic layers between adjacent mineral platelets within a stack is more broadly distributed with the average value varying from 6 nm to 10 nm, depending on the extent of mineralization. The two-dimensional analytical scheme also leads to quantitative information about the preferred orientation of mineral stacks and the average height of crystals along the crystallographic c axis.
Burger
Christian
C
Department of Chemistry, Stony Brook University, Stony Brook, New York, USA.
Zhou
Hong-Wen
HW
Wang
Hao
H
Sics
Igors
I
Hsiao
Benjamin S
BS
Chu
Benjamin
B
Graham
Lila
L
Glimcher
Melvin J
MJ
D000818:Animals; D001842:Bone and Bones / Q000737:chemistry* / Q000648:ultrastructure*; D002113:Calcification, Physiologic; D003198:Computer Simulation; D003460:Crystallization; D024022:Fibrillar Collagens / Q000737:chemistry* / Q000648:ultrastructure*; D005399:Fishes; D008903:Minerals / Q000737:chemistry*; D008954:Models, Biological; D008956:Models, Chemical; D008968:Molecular Conformation
D024022:Fibrillar Collagens; D008903:Minerals