title: An ultrastructural and cytochemical analysis of the cellular basis for tyrosine-derived collagen crosslinks in Leptogorgia virgulata (Cnidaria: Gorgonacea).
abstract: Electron-microscopical autoradiography and cytochemical techniques have been used to identify the distinct and separate subcellular structures involved in the secretion of 1) procollagen, 2) dihydroxyphenylalanine (DOPA), which is a precursor of a collagen-crosslinking compound, and 3) DOPA oxidase, which converts DOPA to a putative crosslinking compound of collagen in the axial skeleton of the gorgonian coral Leptogorgia virulata. Some skeletal-protein hydrolysates contain material that co-elutes with DOPA. The data indicate that these skeletogenic cells, corticocytes, are capable of modifying the number of non-reducible, tyrosine-derived crosslinkages of collagen by the secretion of a crosslinking compound that acts extracellularly on collagen. A mechanism for a cell-mediated control of the mechanical properties of collagen is thereby presented.
mesh_terms: D000818:Animals; D001345:Autoradiography; D003063:Cnidaria / Q000648:ultrastructure*; D003094:Collagen / Q000032:analysis*; D004295:Dihydroxyphenylalanine / Q000032:analysis; D004298:Dopamine / Q000032:analysis; D046911:Macromolecular Substances; D008854:Microscopy, Electron; D014442:Monophenol Monooxygenase / Q000032:analysis; D014316:Tritium; D014443:Tyrosine
chemical_list: D046911:Macromolecular Substances; D014316:Tritium; D014443:Tyrosine; D004295:Dihydroxyphenylalanine; D003094:Collagen; D014442:Monophenol Monooxygenase; D004298:Dopamine