Isolation and characterisation of low-molecular weight protein from safflower seeds (Carthamus tinctorius L.).

The low molecular weight (LMW) protein fraction, often termed the 2s component, was isolated from
safflower seed (Carthamus tinctorius L.). The LMW protein fraction, even though it sediments as a
single peak with an S20,vwa lue of 1.5 S in the analytical ultracentrifuge, appears to be a group of several
LMW proteins as indicated by polyacrylamide gel electrophoresis and DEAE-cellulose chromatography.
The protein was characterized in terms of ultraviolet and fluorescence spectra, extinction coefficient,
sedimentation coefficient, carbohydrate and phosphorus contents, several enzyme activities, and secondary
structure. The protein has nearly 30% a-helix and 47% @-sheet in its secondary structure. Amino acid
analysis of the protein indicates that the protein is rich in glutamic acid or glutamine and arginine. A
chromophore is present along with the protein. The optical properties of the protein change upon dialysis
due to dissociation of the chromophore.