NO and CO binding profiles of hemoglobin vesicles as artificial oxygen carriers

Hiromi Sakai, Atsushi Sato, Peter Sobolewski, Shinji Takeoka, John A. Frangos, Koichi Kobayashi, Marcos Intaglietta, Eishun Tsuchida

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20 Citations (Scopus)

Abstract

Hemoglobin vesicles (HbVs) are artificial oxygen carriers encapsulating purified and concentrated Hb solution in phospholipid vesicles (liposomes). We examined in-vitro reaction profiles of a formulation of HbV with NO and CO in anaerobic and aerobic conditions using stopped-flow spectrophotometry and a NO electrode. Reaction rate constants of NO to deoxygenated and oxygenated HbV were considerably smaller than those of cell-free Hb because of the intracellular NO-diffusion barrier. The reaction of CO with deoxygenated HbV was slightly slower than that of cell-free Hb solely because of the co-encapsulated allosteric effector, pyridoxal 5'-phosphate. The NO depletion in an aerobic condition in the presence of empty vesicles was monitored using a NO electrode, showing that the hydrophobic bilayer membrane of HbV, which might have higher gas solubility, does not markedly facilitate the O2 and NO reaction, and that the intracellular Hb is the major component of NO depletion. In conclusion, HbV shows retarded gas reactions, providing some useful information to explain the absence of vasoconstriction and hypertension when they are intravenously injected.

Original languageEnglish
Pages (from-to)1441-1447
Number of pages7
JournalBiochimica et Biophysica Acta - Proteins and Proteomics
Volume1784
Issue number10
DOIs
Publication statusPublished - 2008 Oct 1

Keywords

  • Artificial red cells
  • Blood substitutes
  • CO
  • Liposome
  • NO
  • Vasoconstriction

ASJC Scopus subject areas

  • Analytical Chemistry
  • Biophysics
  • Biochemistry
  • Molecular Biology

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  • Cite this

    Sakai, H., Sato, A., Sobolewski, P., Takeoka, S., Frangos, J. A., Kobayashi, K., Intaglietta, M., & Tsuchida, E. (2008). NO and CO binding profiles of hemoglobin vesicles as artificial oxygen carriers. Biochimica et Biophysica Acta - Proteins and Proteomics, 1784(10), 1441-1447. https://doi.org/10.1016/j.bbapap.2008.03.007