1R1X

Crystal structure of oxy-human hemoglobin Bassett at 2.15 angstrom

Summary for 1R1X

• Entry DOI: 10.2210/pdb1r1x/pdb
• Related: 1R1Y
• Descriptor: Hemoglobin alpha chain, Hemoglobin beta chain, CARBON MONOXIDE, ... (6 entities in total)
• Functional Keywords: hemoglobin, carbon monoxide, mutant, rochester, oxygen affinity, oxygen transport
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 2
• Total formula weight: 32469.81

Authors

Abdulmalik, O.,Safo, M.K.,Lerner, N.B.,Ochotorena, J.,Dhaikin, Y.,Abraham, D.J.,Asakura, T. (deposition date: 2003-09-25, release date: 2003-10-07, Last modification date: 2023-08-23)

Primary citation

Abdulmalik, O.,Safo, M.K.,Lerner, N.B.,Ochotorena, J.,Daikhin, Y.,Lakka, V.,Santacroce, R.,Abraham, D.J.,Asakura, T.
Characterization of hemoglobin bassett (alpha94Asp-->Ala), a variant with very low oxygen affinity
Am.J.Hematol., 77:268-276, 2004

PubMed Abstract: Hemoglobin (Hb) Bassett, an abnormal Hb variant with a markedly reduced oxygen affinity, was discovered in a Caucasian (Anglo-Saxon) male child who experienced episodes of cyanosis. Cation-exchange and reversed-phase (RP) high-performance liquid chromatography (HPLC) showed that the patient has an abnormal Hb, with a mutation in the alpha-globin. Tryptic peptide digest of the abnormal alpha-globin with subsequent HPLC analysis revealed abnormal elution of the alpha-T11 peptide. Further studies with Edman sequencing and electrospray mass spectrometry of tryptic peptide alpha-T11, as well as structural analysis by X-ray crystallography revealed an Asp-->Ala substitution at the alpha94 (G1) position, a match for Hb Bassett. Detailed functional studies showed that this Hb variant had a markedly reduced oxygen affinity (P(50) at pH 7.0 = 22 mmHg; Hb A P(50) = 10.5 mmHg), reduced Bohr effect (-0.26 compared to - 0.54 in Hb A), and low subunit cooperativity (n = 1.4, compared to 2.6 in Hb A). X-ray crystallography results explain the probable effects of the structural modification on the oxygen-binding properties of this Hb variant.

PubMed: 15495251
DOI: 10.1002/ajh.20184

Experimental method

X-RAY DIFFRACTION (2.15 Å)