Properties of electroplax protein part III

Abstract

• 1.

  1. The isolation and characterization of a protein fraction from the electric organ of Electrophorus electricus is described. The protein was a material of relatively low molecular weight. It was soluble in water, dilute base and dilute acid and had many of the characteristics of mucoproteins.

• 2.

  2. Analytical studies revealed the presence of galactose, N-acetylgalactosamine, glucuronic acid and of N-acetylneuraminic acid. Evidence is presented which indicated, however, that the carbohydrate constituents did not occur as a single polysaccharide moiety. The protein or polypeptide moiety apparently does not contain any of the aromatic amino acids.

• 3.

  3. Physical studies of the isolated sialoprotein reveal marked polyanionic characteristics. Dye-binding and dye-displacement studies as measured by fluorescence quenching demonstrated that “receptor-like” function was simulated by this materiall. It was concluded, however, that this particular sialoprotein, in the form isolated, merely showed ion-exchange capabilities and lacked the high degree of specificity postulated for biological receptors.