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O 2 Binding and Dissociation and Ligand Exchange Reaction of O 2 with CO in Polymer Composite Films of Hemoglobin
Author(s) -
Park Sung Ick,
Sakai Hiromi,
Takeoka Shinji,
Nishide Hiroyuki,
Tsuchida Eishun
Publication year - 1997
Publication title -
polymers for advanced technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 90
eISSN - 1099-1581
pISSN - 1042-7147
DOI - 10.1002/(sici)1099-1581(199706)8:6<366::aid-pat654>3.0.co;2-g
Subject(s) - polymer , dissociation (chemistry) , materials science , composite number , hemoglobin , molecule , ligand (biochemistry) , polymer chemistry , chemical engineering , oxygen , oxygen transport , chemistry , organic chemistry , composite material , receptor , biochemistry , engineering
A polymer composite film of hemoglobin (Hb–polymer film) was prepared by the casting of an Hb–polymer mixed solution (weight ratio of Hb to polymer is 1 to 1). The percentages of O 2 and CO saturation of the Hb–dextran film were 46% and 70%, respectively. In the Hb solution, 100% saturation was observed for both ligands, and a humidified Hb–dextran film also showed 100% saturation. Water molecules would provide flexibility to the matrix polymer and promote a structural change in the Hb from a tense state (T) to a relaxed state (R). Thus the ligand binding to the Hb in the polymer films was strongly affected by the degree of interaction of Hb with the matrix polymers and the physical properties of the polymers. Inositol hexaphosphate (IHP) worked as an allosteric effector even in the solid polymer film and lowered the oxygen affinity of Hb. The O 2 transport through an Hb–polyethyleneimine (PEI) film with IHP showed the facilitated O 2 transport in comparison with the film without IHP because of the high dissociation rate of O 2 from Hb with IHP. © 1997 John Wiley & Sons, Ltd.