Purification and characterization of selenium-containing phycocyanin from selenium-enriched Spirulina platensis

Phytochemistry. 2006 Nov;67(22):2424-30. doi: 10.1016/j.phytochem.2006.08.004. Epub 2006 Sep 14.

Abstract

A fast protein liquid chromatographic method for purification of selenium-containing phycocyanin (Se-PC) from selenium-enriched Spirulina platensis was described in this study. The purification procedures involved fractionation by ammonium sulfate precipitation, DEAE-Sepharose ion-exchange chromatography and Sephacry S-300 size exclusion chromatography. The purity ratio (A620/A280) and the separation factor (A620/A655) of the purified Se-PC were 5.12 and 7.92, respectively. The Se concentration of purified Se-PC was 496.5 microg g(-1) protein, as determined by ICP-AES analysis. The purity of the Se-PC was further characterized by UV-VIS and fluorescence spectrometry, SDS-PAGE, RP-HPLC and gel filtration HPLC. The apparent molecular mass of the native Se-PC determined by gel filtration HPLC was 109 kDa, indicating that the protein existed as a trimer. SDS-PAGE of the purified Se-PC yielded two major bands corresponding to the alpha and beta subunits. A better separation of these two subunits was obtained by RP-HPLC. Identification of the alpha and beta subunits separated by SDS-PAGE and RP-HPLC was achieved by peptide mass fingerprinting (PMF) using MALDI-TOF-TOF mass spectrometry.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromatography, Liquid
  • Electrophoresis, Polyacrylamide Gel
  • Molecular Weight
  • Phycocyanin / chemistry*
  • Phycocyanin / isolation & purification*
  • Protein Subunits / isolation & purification
  • Protein Subunits / metabolism
  • Selenium / analysis*
  • Selenium / chemistry
  • Selenium / metabolism
  • Spectrum Analysis
  • Spirulina / chemistry*
  • Spirulina / metabolism

Substances

  • Protein Subunits
  • Phycocyanin
  • Selenium