The coelomic elements of sea urchins (Strongylocentrotus and centrostephanus—VI. Cellulose-acetate membrane electrophoresis

• 1.

  1. Electrophoretic patterns of proteins and acid mucopolysaccharides found in cell-free coelomic fluid and extracts of ceolomic cells of Strongylocentrotus franciscanus, S. purpuratus, and Centrostephanus coronatus differed according to the urchin species. Most of the proteins were PAS-positive.

• 2.

  2. In cell-free coelomic fluid, echinochrome A (6-ethyl-2,3,7-trihydroxynaphthazarin) is bound to one or more PAS-positive proteins, according to the urchin species. The same proteins occur in echinochrome-free fluids. In cell extracts echinochrome occurs in PAS-positive proteins that also have an acid-mucopolysaccharide moiety.

• 3.

  3. Purified echinochrome A conjugated with the proteins ovomucoid and calf-thymus histone, and with macromolecules in fresh cell-free sea-urchin coelomic fluid. It did not conjugate with bovine gamma globulin, or with molecules in concentrated coelomic fluid.