Chromatographic purification and characterization of B-phycoerythrin from Porphyridium cruentum - Semipreparative high-performance liquid chromatographic separation and characterization of its subunits

A fast preparative two-step chromatographic method for purification of B-ph ycoerythrin from Porphyridium cruentum is described. This biliprotein was h omogeneous as determined by sodium dodecyl sulfate-polyacrylamide gel elect rophoresis yielding three closely migrating bands corresponding to its thre e subunits. Baseline separation of its alpha-, beta- and gamma -subunits wa s achieved by a reversed-phase HPLC gradient semipreparative method with a C, large-pore column and a solvent system consisting of 0.05% trifluoroacet ic acid (TFA) in water and 0.05% TFA in acetonitrile. B-Phycoerythrin in di fferent aggregation states and its subunits have been spectroscopically cha racterized. Hexameric B-phycoerythrin has similar secondary and tertiary st ructure than dissociated B-phycoerythrin determined by circular dichroism. (C) 2001 Elsevier Science B.V. All rights reserved.