title: Hemoglobin Roanne [alpha 94(G1) Asp-->Glu]: a variant of the alpha 1 beta 2 interface with an unexpected high oxygen affinity.
abstract: In hemoglobin (Hb) Roanne, the aspartate residue alpha 94(G1) is replaced by a glutamic acid. This residue plays a key role in the structural changes affecting the alpha 1 beta 2 contact area during the deoxy- to oxy-state transition in the hemoglobin molecule. Aspartate alpha 94(G1) is involved in several contacts both in the deoxy- and oxy-structures. The most important of those is a hydrogen bond with asparagine beta 102 (G4), stabilizing the oxygenated structure. Alteration of this contact usually leads to a decrease in oxygen affinity. Hb Roanne is the first example in which an increased oxygen affinity was found as a result of a structural modification at this position. Functional data suggested that the mechanisms responsible for this altered property are a destabilisation of the T-structure and a modification of the allosteric equilibrium.
authors: INSERM U299, Hôpital de Bicêtre, Le Kremlin Bicêtre, France.
authors: J
authors: J
authors: Kister
authors: L
authors: L
authors: Kiger
authors: A
authors: A
authors: Francina
authors: P
authors: P
authors: Hanny
authors: A
authors: A
authors: Szymanowicz
authors: Y
authors: Y
authors: Blouquit
authors: D
authors: D
authors: Promé
authors: F
authors: F
authors: Galactéros
authors: J
authors: J
authors: Delaunay
authors: H
authors: H
authors: Wajcman
mesh_terms: D000368:Aged; D001224:Aspartic Acid; D001665:Binding Sites; D002248:Carbon Monoxide / Q000378:metabolism; D005260:Female; D018698:Glutamic Acid; D006455:Hemoglobins, Abnormal / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D006860:Hydrogen Bonding; D007525:Isoelectric Focusing; D007700:Kinetics; D013058:Mass Spectrometry; D015394:Molecular Structure; D010100:Oxygen / Q000097:blood*; D013329:Structure-Activity Relationship
chemical_list: D006455:Hemoglobins, Abnormal; C091388:hemoglobin Roanne; D001224:Aspartic Acid; D018698:Glutamic Acid; D002248:Carbon Monoxide; D010100:Oxygen