Screening, purification, and identification of a copper-dependent FITC-binding protein in human plasma: Albumin

Yu Wei Wu, Sung Fang Chen, Charng Bin Yang, Yu Hui Tsai

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6 Citations (Scopus)


In this study, a protein purified by fluorescein isothiocyanate (FITC)-affinity chromatography from human plasma was identified as albumin by MALDI-TOF-MS. Albumin was found to conjugate with FITC-labeled molecules through a copper-dependent reaction. The formation of this complex was confirmed by methods including a newly developed "charcoal-based fluorescence assay" (CFA), gel-filtration, affinity chromatography, and ultrafiltration. The binding was identified as disulfide bridge formation. This is the first to demonstrate that copper induces a covalent binding of FITC-labeled molecules with albumin. In addition, the developed CFA method facilitates the screening of small fluorescent dyes binding to macromolecules.

Original languageEnglish
Pages (from-to)187-191
Number of pages5
JournalJournal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences
Issue number1
Publication statusPublished - Feb 15 2008



  • Affinity
  • Albumin
  • Copper
  • FITC
  • Purification

ASJC Scopus subject areas

  • Biochemistry

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