Submitted to: American Leather Chemists Association Meeting
Publication Type: Proceedings
Publication Acceptance Date: 5/1/2007
Publication Date: 6/20/2007
Citation: Brown, E.M., Qi, P.X. 2007. Exploring a role in tanning for the gap region of the collagen fibril. In: Proceedings of International Union of Leather Technologists and Chemists Societies and American Leather Chemists Association Conference, June 20-24, 2007, Washington, D.C. 2007 CDROM. Interpretive Summary:
Technical Abstract: Three-dimensional structures of fibrillar collagens have been the subject of numerous studies for more than 60 years. Electron micrographs of stained collagen fibrils display a pattern of alternating light and dark bands perpendicular to the axis of the collagen fibril. Light bands correspond to regions of more dense lateral packing where adjacent collagen monomers overlap, and dark bands correspond to 'gap' regions, domains of low-density molecular packing. This banded pattern results from the staggering of triple helical monomers in the assembly of the fibril. A pair of overlap (0.4D) and gap (0.6D) bands comprise a single D-space of about 670 Å. Telopeptides, the nonhelical extensions at the N- and C- terminus of each collagen chain, extend into the gap regions of the fibril and provide anchors for the natural crosslinking that occurs as an animal ages. Most studies of artificially stabilized collagen focus on crosslinks that utilize specific amino acid side chains, without considering whether these are more likely to be located in overlap or gap regions. The gap region with its lower molecular density, greater length, and available telopeptides appears promising as an area able to accommodate oligomeric compounds that are the typical tanning agents. This study uses the ERRC collagen model to explore the potential effects on the secondary and tertiary structure of collagen when tanning agents of different types are stabilized within the gap region of the microfibril. A possible reaction mechanism for bio-tanning reagents is discussed in light of the active role of these gap regions.