title: Relevance of aggregation properties of tropoelastin to the assembly and structure of elastic fibers.
abstract: Solutions of tropoelastin incubated under different experimental conditions were examined by electron microscopy after negative staining and after fixation and embedding. Below 37 degrees C only polymorphous structureless elements of variable size could be found. In samples kept for a few minutes at 40 degrees C, flexible, isolated filaments of 5 nm diameter and variable length, together with a few small aggregates of filaments, were seen. No single filaments, but only bundles of filaments were detectable after incubation at 40 degrees C for longer than 5-10 min. Tropoelastin kept at 40 degrees C for longer than 10 hr formed a white precipitate, which, when fixed and embedded as in conventional electron microscopy, consisted of 0.5-2 microns thick, amorphous and branching fibers, identical to those seen in identically processed normal tissues. From these observations a model for the assembly and structure of elastic fibers is proposed.
mesh_terms: D000818:Animals; D002645:Chickens; D004547:Elastic Tissue / Q000378:metabolism* / Q000648:ultrastructure; D004549:Elastin / Q000031:analogs & derivatives*; D006358:Hot Temperature; D046911:Macromolecular Substances; D008854:Microscopy, Electron; D008958:Models, Molecular; D014333:Tropoelastin / Q000378:metabolism*
chemical_list: D046911:Macromolecular Substances; D014333:Tropoelastin; D004549:Elastin