The specific aims of this research proposal are: 1) to synthesize component peptides of the elastic fiber, i.e. the repeat peptides, actual sequences containing the repeats, multicomponent models comprised of the repeats, and composities approaching tropoelastin, and 2) to develop three dimensional structures for the peptides for the purpose of understanding the molecular structure, function and pathology of the elastic fiber, utilizing the disciplines of molecular biophysics and pathobiological chemistry. The approach is to study a series of relevant molecular systems of graded, increasing complexity and to do so in each of three states, solution, coacervate and fibrous, which constitute a set of states of graded, increasing complexity. The chemical methods to be used are those of solution and solid phase peptide synthesis. The physical and computational characterizations utilize proton and carbon-13 NMR (including solid state), nuclear Overhauser effects, relaxation studies, CD and UV spectroscopies, and X-ray diffraction in a combined effort to place conformational constrains on the molecular systems and to use conformational energy analyses for further constraints in a stepwise manner to develop descriptions of preferred conformations. These data, at the Beta-spiral and twisted filament level of development, will be combined with ultrastructural characterizations of microscopy (light, scanning and conventional with negative staining) and molecular graphics to obtain a consistent and detailed description of the filamentous structures comprising the fibrous states. The methods utilized in studying the molecular pathology of each of the relevant molecular systems are: calcium-43 NMR relaxation studies to characterize calcium binding, columns made of the fibrous states to study lipid binding, serum dialysate calcification (characterized by SEM and microanalysis), and prolyl hydroxylation as it relates to fiber formation and to degradation by elastase. The elastic fiber is a primary site for the molecular pathologies of calcification and lipid deposition, and is implicated in such disease processes as atherosclerosis, pulmonary emphysema, solar elastosis, and other complications of the connective tissue which are relevant to heart and lung diseases and to aging processes.
Showing the most recent 10 out of 44 publications
