Comparative study of the high molecular weight protein fraction of mustard (B. juncea) and rapeseed (B. campestris)

A method is described for isolating the high mol. wt. protein fraction of mustard and rapeseed in a homogeneous form. The protein from the two species had nearly identical sedimentation coefficients, molecular weights, intrinsic viscosity and fluorescence emission spectrum. However, differences in the amino acid composition were observed. Data on circular dichroism and rate of hydrolysis by proteolytic enzymes suggested differences in the secondary structures and possibly amino acids sequence.