Ultrastructural localization of Helix pomatia lectin-binding sites in mouse lung elastic fibers.

Helix pomatia (Snail) lectin complexed with colloidal gold (HPL-gold) recognized binding sites on elastic fibers in plastic embedded sections of lung tissue from mice of several ages. Deposition of the lectin-gold particles was examined by electron microscopy. Structures such as the elastic laminae of pulmonary vessels and elastic fibers throughout the lung was specifically and intensely decorated by the HPL-gold complex and easily visualized. The binding of the HPL-gold particles was primarily to sites on the amorphous component of elastin, to the virtual exclusion of the microfibrillar elastin elements, collagen fibers and other components of the extracellular matrix. In addition, moderate age differences in the binding of HPL-gold to elastin were apparent. These observations appear to be the first demonstration of the presence, in the amorphous component of elastin, of glycoconjugates that are specifically recognized by HPL and suggest a method by which the involvement of glycoconjugates in lung elastogenesis could be explored.