title: Hemoglobin Kirklareli (α H58L), a New Variant Associated with Iron Deficiency and Increased CO Binding.
abstract: Mutations in hemoglobin can cause a wide range of phenotypic outcomes, including anemia due to protein instability and red cell lysis. Uncovering the biochemical basis for these phenotypes can provide new insights into hemoglobin structure and function as well as identify new therapeutic opportunities. We report here a new hemoglobin α chain variant in a female patient with mild anemia, whose father also carries the trait and is from the Turkish city of Kirklareli. Both the patient and her father had a His-58(E7) → Leu mutation in α1. Surprisingly, the patient's father is not anemic, but he is a smoker with high levels of HbCO (∼16%). To understand these phenotypes, we examined recombinant human Hb (rHb) Kirklareli containing the α H58L replacement. Mutant α subunits containing Leu-58(E7) autoxidize ∼8 times and lose hemin ∼200 times more rapidly than native α subunits, causing the oxygenated form of rHb Kirklareli to denature very rapidly under physiological conditions. The crystal structure of rHb Kirklareli shows that the α H58L replacement creates a completely apolar active site, which prevents electrostatic stabilization of bound O2, promotes autoxidation, and enhances hemin dissociation by inhibiting water coordination to the Fe(III) atom. At the same time, the mutant α subunit has an ∼80,000-fold higher affinity for CO than O2, causing it to rapidly take up and retain carbon monoxide, which prevents denaturation bothin vitroandin vivoand explains the phenotypic differences between the father, who is a smoker, and his daughter.
authors.affiliation: From the Institute for Clinical Chemistry and Laboratory Medicine, University Medical Center, Hugstetterstrasse 55, D-79106 Freiburg, Germany.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Bissé
authors.affiliation: the BioOrganic Mass Spectrometry Laboratory (LSMBO), IPHC, Université de Strasbourg, 25 Rue Becquerel, 67087 Strasbourg, France.|the IPHC, CNRS, UMR7178, 67087 Strasbourg, France, and.
authors.forename: Christine
authors.initials: C
authors.lastname: Schaeffer-Reiss
authors.affiliation: the BioOrganic Mass Spectrometry Laboratory (LSMBO), IPHC, Université de Strasbourg, 25 Rue Becquerel, 67087 Strasbourg, France.|the IPHC, CNRS, UMR7178, 67087 Strasbourg, France, and.
authors.forename: Alain
authors.initials: A
authors.lastname: Van Dorsselaer
authors.affiliation: the BioOrganic Mass Spectrometry Laboratory (LSMBO), IPHC, Université de Strasbourg, 25 Rue Becquerel, 67087 Strasbourg, France.|the IPHC, CNRS, UMR7178, 67087 Strasbourg, France, and.
authors.forename: Tchilabalo Dilezitoko
authors.initials: TD
authors.lastname: Alayi
authors.affiliation: From the Institute for Clinical Chemistry and Laboratory Medicine, University Medical Center, Hugstetterstrasse 55, D-79106 Freiburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Epting
authors.affiliation: From the Institute for Clinical Chemistry and Laboratory Medicine, University Medical Center, Hugstetterstrasse 55, D-79106 Freiburg, Germany.
authors.forename: Karl
authors.initials: K
authors.lastname: Winkler
authors.affiliation: the BioSciences Department, Rice University, Houston, Texas 77281.
authors.forename: Andres S
authors.initials: AS
authors.lastname: Benitez Cardenas
authors.affiliation: the BioSciences Department, Rice University, Houston, Texas 77281.
authors.forename: Jayashree
authors.initials: J
authors.lastname: Soman
authors.affiliation: the BioSciences Department, Rice University, Houston, Texas 77281.
authors.forename: Ivan
authors.initials: I
authors.lastname: Birukou
authors.affiliation: the BioSciences Department, Rice University, Houston, Texas 77281.
authors.forename: Premila P
authors.initials: PP
authors.lastname: Samuel
authors.affiliation: the BioSciences Department, Rice University, Houston, Texas 77281 olson@rice.edu.
authors.forename: John S
authors.identifier: 0000-0002-0760-5403
authors.initials: JS
authors.lastname: Olson
mesh_terms: D000328:Adult; D018798:Anemia, Iron-Deficiency / Q000097:blood*; D002248:Carbon Monoxide / Q000378:metabolism*; D020134:Catalytic Domain; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D056148:Chromatography, Reverse-Phase; D018360:Crystallography, X-Ray; D005260:Female; D006455:Hemoglobins, Abnormal / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D010084:Oxidation-Reduction; D010100:Oxygen / Q000378:metabolism; D055672:Static Electricity; D055815:Young Adult
chemical_list: D006455:Hemoglobins, Abnormal; D002248:Carbon Monoxide; D010100:Oxygen
keywords: carbon monoxide; heme; hemoglobin; mutant; oxidative stress