Physicochemical characterization of cross-linked human serum albumin dimer and its synthetic heme hybrid as an oxygen carrier

Teruyuki Komatsu, Yukiko Oguro, Yuji Teramura, Shinji Takeoka, Junpei Okai, Makoto Anraku, Masaki Otagiri, Eishun Tsuchida

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37 Citations (Scopus)


The recombinant human serum albumin (rHSA) dimer, which was cross-linked by a thiol group of Cys-34 with 1,6-bis(maleimido)hexane, has been physicochemically characterized. Reduction of the inert mixed-disulfide of Cys-34 beforehand improved the efficiency of the cross-linking reaction. The purified dimer showed a double mass and absorption coefficient, but unaltered molar ellipticity, isoelectric point (pI: 4.8) and denaturing temperature (65°C). The concentration dependence of the colloid osmotic pressure (COP) demonstrated that the 8.5 g dL -1 dimer solution has the same COP with the physiological 5 g dL -1 rHSA. The antigenic epitopes of the albumin units are preserved after bridging the Cys-34, and the circulation lifetime of the 125I-labeled variant in rat was 18 h. A total of 16 molecules of the tetrakis{(1-methylcyclohexanamido)phenyl}porphinatoiron(II) derivative (FecycP) is incorporated into the hydrophobic cavities of the HSA dimer, giving an albumin-heme hybrid in dimeric form. It can reversibly bind and release O 2 under physiological conditions (37°C, pH 7.3) like hemoglobin or myoglobin. Magnetic circular dichroism (CD) revealed the formation of an O 2-adduct complex and laser flash photolysis experiments showed the three-component kinetics of the O 2-recombination reaction. The O 2-binding affinity and the O 2-association and -dissociation rate constants of this synthetic hemoprotein have also been evaluated.

Original languageEnglish
Pages (from-to)21-31
Number of pages11
JournalBiochimica et Biophysica Acta - General Subjects
Issue number1-3
Publication statusPublished - 2004 Nov 18


  • Albumin-heme dimer
  • Colloid osmotic pressure
  • Cross-linking
  • Human serum albumin dimer
  • Oxygen carrier
  • Synthetic heme

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology


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