Hemoglobin equilibrium analysis by the multiangle laser light-scattering method.
Dimer-tetramer and monomer-dimer-tetramer equilibria of tetrameric hemoglobins and their single chains in the CO form, respectively, were evaluated using the microbatch multiangle light-scattering (MALS) analysis system. The molecular weights of human Hb A and Hb F in the CO form were dependent on concentration. The dissociation constants to dimers of Hb A and Hb F were 2.58 x 10(-6) and 0.66 x 10(-6), respectively. Equilibration of single globin chains, including alpha, beta, and gamma chains, was also evaluated by the same method. The dissociation constants of alpha-chain dimers to monomers, of beta-chain tetramers to monomers, and of gamma-chain tetramers to dimers were 14 x 10(-6), 25 x 10(-17), and 6.86 x 10(-6) M, respectively. These results indicate that the MALS analysis system can not only determine molecular weight but also characterize protein-protein interactions of multi-subunit proteins.
Yamaguchi
Takamasa
T
Division of Hematology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.
Adachi
Kazuhiko
K
D000328:Adult; D002263:Carboxyhemoglobin / Q000737:chemistry; D019281:Dimerization; D005312:Fetal Blood; D005319:Fetal Hemoglobin / Q000737:chemistry*; D005914:Globins / Q000737:chemistry; D006441:Hemoglobin A / Q000737:chemistry*; D006801:Humans; D007834:Lasers; D008027:Light; D008970:Molecular Weight; D010446:Peptide Fragments / Q000737:chemistry; D012542:Scattering, Radiation; D012710:Serum Albumin, Bovine / Q000737:chemistry
D010446:Peptide Fragments; D012710:Serum Albumin, Bovine; D005914:Globins; D006441:Hemoglobin A; D005319:Fetal Hemoglobin; D002263:Carboxyhemoglobin