Isolation,Amino Acid composition and molecular weight distribution ofEucalyptus kirtoniana seed proteins

Proteins were extracted from the deoiled seeds ofEucalyptus kirtoniana in aqueous solutions of various pHs or by different concentrations of NaCl, Na₂SO₃, CaCl₂ and MgCl₂ at pH 8.0. Amino acid analysis of the isolated protein identified 16 amino acids, nine of which were essential. Gel permeation chromatography on Sephadex G-200 revealed the presence of four components in the protein fraction, and their molecular weights were determined by two comparable standard methods. SDS-PAG electrophoresis demonstrated that each protein isolate from different salt solutions was composed of six fractions whose molecular weights were estimated to be 131,800; 108,300; 93,300; 51,300; 38,000 and 25,700 daltons.