CHARACTERIZATION AND CRYSTALLIZATION OF AN 11S SEED STORAGE GLOBULIN FROM COCONUT (COCOS-NUCIFERA)

Cocosin, an 11S seed storage globulin from coconut, has been purified and characterised by HPLC gel filtration and anion-exchange chromatography. At least eight different subunit species have been identified. Despite this heterogeneity, cocosin crystallises very readily into forms typical of this class of protein. The molecular weight of the protein was in the range 250 000-300 000, higher than the value of 208 000 previously ascribed. A subunit molecular weight of approximately 54 000, together with the crystal symmetry, suggests that cocosin is a typical hexameric 11S globulin, and not a tetramer as was previously postulated. © 1990.