Cross Linking of Collagen by Hydrophobe Bonds

Abstract

Previous work on modification of the collagen lattice, presented at these meetings, has served to confirm the Ramachandran proposal for the structure of this important protein, together with information on the lengths and tensile strengths of these bonds, including hydrogen bonds, hydrophobe bonds, and Vander Waals attractions. Rat tail tendons were suspended in 2 M aqueous solutions of dimethylsulfoxide, acetone, trimethylamineoxide and 1,4-cyclohexanedione, all of which showed evidence of ligation by expansion of the collagen lattice and refinement of the 100 spot in the x-ray diffraction pattern run by rotation on the collagen fiber axis. In the case of trimethylamineoxide and cyclohexanedione, oriented crystallization also occurred, with the long direction of the molecule in the plane perpendicular to the fiber axis of collagen. With the monofunctional ligands, the -C=0 group forms a hydrogen bond to the N-H group in the Ramachandran standard revised model, leaving the methyl groups to form the hydrophobe bond.