AGGREGATION PROPERTIES OF C-PHYCOCYANIN FROM ANACYSTIS NIDULANS

1. 1. Gel filtration measurements indicate that the minimum molecular weight of C-phycocyanin from Anacystis nidulans is about 30 000. Both the gel filtration and sedimentation data support the view that the molecule associates to form dimers, hexamers and dodecamers. 2. 2. The hexamer is the predominant component at low pH and high protein concentration. Dilution completely converts the hexamer to monomer at low pH and to dimer at high pH. 3. 3. The extinction coefficient of the protein at the absorption maximum is pH dependent; maximal absorption occurs at about pH 6.0. The absorption maximum shifts from 613 mμ at pH 3.5 to 622 mμ at pH 8.5. © 1969.