Characterization of the proteins of Pili nut (Canarium ovatum,Engl.)

The storage proteins of the pili nut (Canarium ovatum, Engl.), quantitatively extracted using the modified Osborne protein fractionationscheme, revealed that the salt-soluble globulin was the main storage proteinwithin the kernel (i.e., >>60.3%). Further physicochemicalcharacterization of this aqueous soluble globulin revealed that it existed in an11S like form and was composed of two main subunits of 22,600 and31,600 Da. These subunits were found to be disulfide-linked (in a 1:1ratio) forming intermediary subunits (i.e., dimers) with a molecular weightof approximately 52,600 Da. The overall molecular weight of the 11Sglobulin was determined to be approximately 300,000 Da suggesting thatthe globulin possessed a dodecameric-like structure of 6 dimers for a totalof 12 subunits. Using differential scanning microcalorimetry, thedenaturation temperature of the globulin was shown to occur at89.3 ^°C. Overall, the pili nut 11S globulin was found to possessmany similar physicochemical properties to those of other 11S oilseedglobulins.