The salmonid elastic fibril

Elastic fibrils were isolated, as electron microscopically homogeneous preparations, from salmon (Salmo salar) and trout (Salmo gairdneri) bulbus arteriosus by extraction of other tissue components with guanidinium hydrochloride. The preparations exhibited compositions widely at variance with that of bovine elastin, the differences including both the overall concentration and the relative proportions of the crosslinks. Absorption and fluorescence spectroscopy ruled out the presence of tyrosine-derived crosslinks. The wide-angle X-ray diffraction pattern of the salmonid preparations showed broad reflections corresponding to spacings of 9.8, 4.5, and 2.2 Å, similar to bovine elastin. The mechanical behavior of the salmon preparation was characterized by a linear response to stress, with minimal hysteresis, a Young's modulus of 5.5 × 105 N m−2, and a breaking strain of 1.5.