caa a22 4500 475744373 CHVBK 20180406123509.0 cr unu---uuuuu 170329e20001101xx s 000 0 eng 10.1023/A:1007196118200 doi (NATIONALLICENCE)springer-10.1023/A:1007196118200 Expression and Properties of Recombinant HbA2 (α2δ2) and Hybrids Containing δ-β Sequences [Elektronische Daten] [Kenji Inagaki, Junko Inagaki, Antoine Dumoulin, Julio Padovan, Brian Chait, Anthony Popowicz, Lois Manning, James Manning] Hemoglobin A2 (α2δ2), which is present at low concentration (1-2%) in the circulating red cells of normal individuals, has two important features that merit its study, i.e., it inhibits polymerization of sickle HbS and its elevated concentration in some thalassemias is a useful clinical diagnostic. However, reports on its functional properties regarding O2 binding are conflicting. We have attempted to resolve these discrepancies by expressing, for the first time, recombinant hemoglobin A2 and systematically studying its functional properties. The construct expressing HbA2 contains only α and δ genes so that the extensive purification required to isolate natural HbA2 is circumvented. Although natural hemoglobin A2 is expressed at low levels in vivo, the amount of recombinant α2δ2 expressed in yeast is similar to that found for adult hemoglobin A and for fetal hemoglobin F when the α + β or the α + γ genes, respectively, are present on the construct. Recombinant HbA2 is stable, i.e., not easily oxidized, and it is a cooperative functional hemoglobin with tetramer-dimer dissociation properties like those of adult HbA. However, its intrinsic oxygen affinity and response to the allosteric regulators chloride and 2,3-diphosphoglycerate are lower than the corresponding properties for adult hemoglobin. Molecular modeling studies which attempt to understand these properties of HbA2 are described. Plenum Publishing Corporation, 2000 Hemoglobin nationallicence tetramer strength nationallicence delta gene nationallicence allosteric regulator nationallicence Inagaki Kenji Okayama University, Okayama, Japan aut Inagaki Junko Okayama University, Okayama, Japan aut Dumoulin Antoine Valigene, 92086, Paris, France aut Padovan Julio Mass Spectrometry Laboratory, Computing Services, Rockefeller University, 10021, New York, New York aut Chait Brian Mass Spectrometry Laboratory, Computing Services, Rockefeller University, 10021, New York, New York aut Popowicz Anthony Mass Spectrometry Laboratory, Computing Services, Rockefeller University, 10021, New York, New York aut Manning Lois Department of Biology, Northeastern University, 02115, Boston, Massachusetts aut Manning James Department of Biology, Northeastern University, 02115, Boston, Massachusetts aut Journal of Protein Chemistry Kluwer Academic Publishers-Plenum Publishers 19/8(2000-11-01), 649-662 0277-8033 19:8<649 2000 19 10930 https://doi.org/10.1023/A:1007196118200 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1007196118200 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Inagaki Kenji Okayama University, Okayama, Japan aut NATIONALLICENCE 700 1- Inagaki Junko Okayama University, Okayama, Japan aut NATIONALLICENCE 700 1- Dumoulin Antoine Valigene, 92086, Paris, France aut NATIONALLICENCE 700 1- Padovan Julio Mass Spectrometry Laboratory, Computing Services, Rockefeller University, 10021, New York, New York aut NATIONALLICENCE 700 1- Chait Brian Mass Spectrometry Laboratory, Computing Services, Rockefeller University, 10021, New York, New York aut NATIONALLICENCE 700 1- Popowicz Anthony Mass Spectrometry Laboratory, Computing Services, Rockefeller University, 10021, New York, New York aut NATIONALLICENCE 700 1- Manning Lois Department of Biology, Northeastern University, 02115, Boston, Massachusetts aut NATIONALLICENCE 700 1- Manning James Department of Biology, Northeastern University, 02115, Boston, Massachusetts aut NATIONALLICENCE 773 0- Journal of Protein Chemistry Kluwer Academic Publishers-Plenum Publishers 19/8(2000-11-01), 649-662 0277-8033 19:8<649 2000 19 10930 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer