The proteins of rapeseed (Brassica napus L.) soluble in salt solutions

The salt-soluble proteins from rapeseed (Brassica napus L.), variety Nugget, have been extracted with 0.01 M sodium pyrophosphate (pH 7.0) and with 10% sodium chloride, and subsequently separated into a number of components. There are two major proteins in the pyrophosphate salt extract, one is neutral (the 12 S protein) and the other is basic (the 1.7 S protein). They constitute 30% of the nitrogen in the extract. There are nine other minor components in this extract. The 10% sodium chloride extract contains a water-insoluble protein (the 12 S protein) which constitutes 21% of the nitrogen in the extract and appears to be similar in properties to the 12 S protein in the pyrophosphate salt extract. This protein, upon sedimentation analysis in 6 M urea solution and in 0.1 M glycine–HCl buffer (pH 2.2), appeared to be an aggregate of units of smaller molecular weight.