title: Hemoglobin conjugated with a Band 3 N-terminus derived peptide as an oxygen carrier.
abstract: A peptide composed of 9 amino acids, 7 residues from N-terminus of human erythrocytic Band 3 protein (AcMEELQDD) followed by cysteine and glutamic acids, was conjugated to hemoglobin (Hb) serving as an allosteric effector for oxygen release. The activated polyethylene glycol (PEG), maleimide-PEG-N-hydroxysuccinimidyl, was used to crosslink Hb with the peptide. The putative conjugation site on Hb for effective enhancement of oxygen release was characterized as Lys-beta95 by liquid chromatography-tandem mass spectrometry. In addition, the conjugated peptide causes a rightward shift of the oxygen dissociation curve as compared to that of its parent Hb when the degree of oxygen saturation is higher than 50%. Furthermore, this conjugated peptide remains effective on lowering Hb's oxygen affinity after Hb polymerization by another PEG crosslinker. The allosteric properties of the peptide-conjugated Hb may provide a new aspect of Hb-based oxygen carriers.
authors.affiliation: Department of Chemical Engineering, National Chung Cheng University, Chia-Yi, Taiwan.
authors.forename: Yen-Lin
authors.initials: YL
authors.lastname: Lin
authors.forename: Kuang-Tse
authors.initials: KT
authors.lastname: Huang
mesh_terms: D000595:Amino Acid Sequence; D001457:Anion Exchange Protein 1, Erythrocyte / Q000737:chemistry*; D001665:Binding Sites; D001802:Blood Substitutes / Q000737:chemistry*; D002853:Chromatography, Liquid; D003432:Cross-Linking Reagents / Q000737:chemistry / Q000494:pharmacology; D015180:Electrophoresis, Gel, Two-Dimensional; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D008301:Maleimides / Q000737:chemistry; D008969:Molecular Sequence Data; D010100:Oxygen / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*; D011092:Polyethylene Glycols / Q000737:chemistry; D011485:Protein Binding / Q000187:drug effects; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013388:Succinimides / Q000737:chemistry
chemical_list: D001457:Anion Exchange Protein 1, Erythrocyte; D001802:Blood Substitutes; D003432:Cross-Linking Reagents; D006454:Hemoglobins; D008301:Maleimides; D010455:Peptides; D013388:Succinimides; C043592:maleimide; D011092:Polyethylene Glycols; D010100:Oxygen