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Updated: Aug 8, 2026

T-wave Ion Mobility-mass Spectrometry: Basic Experimental Procedures for Protein Complex Analysis
Published on: July 31, 2010
Further studies on the isolation and properties of alpha-chain sub-units of haemoglobin
1Medical Research Council Group in Haemolytic Anaemias, University College Hospital Medical School, London, W.C. 1, and Department of Biochemistry, University College London, Gower Street, London, W.C. 1.
1. alpha(A)-Chain sub-units have been isolated from neutral haemolysates containing certain unstable beta-chain haemoglobin variants. They are identical, in electrophoretic properties, tryptic peptide analyses and their ability to recombine with Hb-beta(A) (4) at neutral pH, with the alpha(A)-chain sub-units isolated from Hb-A at acid pH. Abnormal alpha(G)-chain sub-units have been prepared from haemolysates containing the alpha-chain variant Hb-G. 2. alpha(A)-Chain sub-units prepared by either method are eluted from Sephadex at low haemoglobin concentration as monomer sub-units. The elution volume, sedimentation coefficient and apparent molecular weight are, however, concentration-dependent, suggesting an equilibrium between monomers and higher polymers with the former as the predominant species. Elevated temperatures cause the alpha(A)-chain sub-unit to aggregate and denature. 3. The product of the reaction between the alpha(A)-chain sub-unit and Hb-beta(A) (4) has been characterized as Hb-A. Only Hb-A and Hb-G can be detected as the products when a mixture of alpha(A)- and alpha(G)-chain sub-units reacts with Hb-beta(A) (4). The absence of the species alpha(A)alpha(G)beta(A) (2) can be explained in terms of the rapid equilibrium between whole and half haemoglobin molecules and the reassortment of alphabeta sub-units during the separation process.
1. alpha(A)-Chain sub-units have been isolated from neutral haemolysates containing certain unstable beta-chain haemoglobin variants. They are identical, in electrophoretic properties, tryptic peptide analyses and their ability to recombine with Hb-beta(A) (4) at neutral pH, with the alpha(A)-chain sub-units isolated from Hb-A at acid pH. Abnormal alpha(G)-chain sub-units have been prepared from haemolysates containing the alpha-chain variant Hb-G. 2. alpha(A)-Chain sub-units prepared by either method are eluted from Sephadex at low haemoglobin concentration as monomer sub-units. The elution volume, sedimentation coefficient and apparent molecular weight are, however, concentration-dependent, suggesting an equilibrium between monomers and higher polymers with the former as the predominant species. Elevated temperatures cause the alpha(A)-chain sub-unit to aggregate and denature. 3. The product of the reaction between the alpha(A)-chain sub-unit and Hb-beta(A) (4) has been characterized as Hb-A. Only Hb-A and Hb-G can be detected as the products when a mixture of alpha(A)- and alpha(G)-chain sub-units reacts with Hb-beta(A) (4). The absence of the species alpha(A)alpha(G)beta(A) (2) can be explained in terms of the rapid equilibrium between whole and half haemoglobin molecules and the reassortment of alphabeta sub-units during the separation process.
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