title: Hb natal or alpha 2(minus Tyr-Arg) beta 2: a high oxygen affinity alpha chain variant with a deleted carboxy-terminus resulting from a TAC----TAA (Tyr----terminating codon) mutation in codon alpha 140.
abstract: The discovery is reported of a fast-moving alpha chain variant (Hb Natal) which is characterized by a shortened alpha polypeptide chain because of the deletion of the Tyr-Arg carboxy-terminal residues. Through amplification of appropriate segments of DNA and hybridization with synthetic oligonucleotide probes, it was possible to detect a C----A mutation in codon 140 of the alpha 2 globin gene, which causes a change in the codon for tyrosine to a terminating codon. Hb Natal or alpha 2 (minus Tyr-Arg) beta 2 has a high affinity for oxygen without a Bohr effect and heme-heme interaction. These results provide direct evidence for the importance of the tyrosine residue at alpha 140 in the oxygenation-deoxygenation process.
authors.affiliation: Department of Haematology, University of Natal, Durban, South Africa.
authors.forename: V B
authors.initials: VB
authors.lastname: Jogessar
authors.forename: K
authors.initials: K
authors.lastname: Westermeyer
authors.forename: B B
authors.initials: BB
authors.lastname: Webber
authors.forename: J B
authors.initials: JB
authors.lastname: Wilson
authors.forename: H
authors.initials: H
authors.lastname: Hu
authors.forename: J M
authors.initials: JM
authors.lastname: Gonzalez-Redondo
authors.forename: A
authors.initials: A
authors.lastname: Kutlar
authors.forename: T H
authors.initials: TH
authors.lastname: Huisman
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D001483:Base Sequence; D002851:Chromatography, High Pressure Liquid; D003062:Codon; D004247:DNA / Q000235:genetics; D015342:DNA Probes; D004586:Electrophoresis; D005784:Gene Amplification; D005914:Globins / Q000235:genetics; D006455:Hemoglobins, Abnormal / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D009693:Nucleic Acid Hybridization; D010100:Oxygen / Q000097:blood*; D010446:Peptide Fragments; D012333:RNA, Messenger; D014357:Trypsin
chemical_list: D000596:Amino Acids; D003062:Codon; D015342:DNA Probes; D006455:Hemoglobins, Abnormal; D010446:Peptide Fragments; D012333:RNA, Messenger; C057761:hemoglobin Natal; D005914:Globins; D004247:DNA; D014357:Trypsin; D010100:Oxygen