Lipid binding proteins from the endosperms of wheat and Oats

Abstract

A protein, designated lipid binding protein (LBP), has been purified from the petrol extracts of wheat and oat endosperms by hydrochloric acid precipitation in a non-polar medium and preparative electrophoresis. The purified LBP appeared to be homogeneous both by electrophoresis in sodium dodecyl sulphate-polyacrylamide (SDS-PAGE) gels (MW ca 14 500) and by electrophoresis (PAGE) at pH 3.2. The amino acid composition indicates a high degree of homology between the LBPs from the two sources, as judged by the indexes of Cornish-Bowden and of Harris and Teller. As in the case of thionin, a previously characterized polypeptide from the ether extract, LBP becomes ether-insoluble, chloroform-soluble by precipitation with acetone, and solubility in ether is restored by binding of digalactosyl diglyceride to the chloroform-soluble form.