The purpose of this project is to investigate the molecular structure of collagen, elastin and proteoglycans, and to correlate the results obtained with function. The area of present interest are 1) Structure of collagen in soft and mineralized tissues. Dipolar decoupled 13C magnetic resonance spectra of collagen fibers in various tissues are being used to study the structure and interactions which characterize the collagen lattice. 2) Proteoglycan structure. Natural abundance 13C magnetic resonance is being used to study the molecular mobility of the polysaccharide and protein chains in bovine cartilage to elucidate the molecular structure and interaction in the tissue. 3) The structure of elastin. Elastin samples, containing 13C labeled amino acids, will be used to elucidate the structure of the various regions of the protein.