Collagen compression forces

Schematic representation of the molecular organization of structural elements in cartilage matrix. Collagen fibrils provide tensile forces, and proteoglycans, because of their large solvent domains, accommodate reversible compressible forces. LP = link protein HA = hyaluronate KS = keratan sulfate CS = chondroitin sulfate PC = core protein. [Reproduced with permission from L. C. Junqueira, J. Carneiro, and J. A. Long, Basic Histology, 5th ed. Appleton Lange, Norwalk, CT, 1986. 1986 Appleton-Century-Crofts.]...

For collagen, repulsive forces start at a distance which is smaller than twice the length of the collagen stiff rod. The force/distance profiles for collagen confirm therefore the interpretation of the adsorption-desorption data. Collagen molecules are attached to the mica surface in a tilted end-on orientation. This orientation varies as a function of compression of the surfaces. The repulsive forces result from the head-to-head contacts of collagen rods or from the interpenetration of the layers. 

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