Native Collagen and Its Structural Fulcrum through a Site Specific Hydration Topology Map

Abstract

Structural account of collagen in its native environment is limited, and a water-mediated hydrogen bonding network as its stability analogue needs to be contemplated site specifically. We present in this Article that, through natural abundance 13C chemical shift anisotropy (CSA) measurement of collagen in its native state (inside bone matrix), structural and mechanistic insight of the water-mediated hydrogen bonding network can be achieved. The 13C CSA of backbone and side chain residues of collagen, perturbed under dehydration and H/D exchange conditions, can be measured. The changes in 13C CSA values due to perturbation of water content have resulted in determining the site-specific accessibility of water molecules. A further hydration topology map (HTM) representing water accessibility of native collagen has been generated on the basis of changes in 13C CSA values. Our results signify the water accessibility of the proline/hydroxyproline carbonyl region is larger compared to the hydroxyproline Cγ site ...