Optical diffraction of tropoelastin and alpha-elastin coacervates.

Optical diffraction applied to micrographs of coacervated tropoelastin and alpha-elastin show an equatorial repeat around 50 A. This confirms a 50 A center-to-center distance of parallel aligned filaments to be a fundamental property of the tropoelastin and alpha-elastin coacervates. This periodicity is similar to that of mature cross-linked elastin. These results allow the conclusion that hydrophobic association is the predominant driving force for formation of filamentous elastin in vitro. It is suggested that the coacervate is a model for relaxed fibrous elastin.