One-step purification of R-phycoerythrin from the red edible seaweed Grateloupia turuturu

A one-step chromatographic method for the purification of R-phycoerythrin (R-PE) of Grateloupia turuturu Yamada is described. Native R-PE was obtained with a purity index of 2.89 and a recovery yield of 27% using DEAE-Sepharose Fast Flow chromatography with a three-step increase in ionic strength. The analysis by SDS electrophoresis showed a broad band between 18 and 21 kDa in size corresponding to subunits alpha and beta and a low intensity band of 29 kDa corresponding to the gamma subunit. Two forms of R-PE were identified by gel filtration chromatography: a native form with a molecular weight of 260 +/- 5 kDa and a dissociated form with a molecular weight of 60 +/- 2 kDa. The native form presented the characteristic absorption spectrum of R-PE with three absorbance maxima at 498, 540 and 565 nm, whereas the dissociated form presented only the 498 and 540nm peaks. Moreover, the two forms displayed two different fluorescence maxima. (C) 2015 Elsevier B.V. All rights reserved.