Conformation-specific antibodies to the alpha chain COOH terminus of hemoglobin A0.
An anti-hemoglobin antiserum obtained from a sheep immunized with human carboxyhemoglobin A0 demonstrated little difference in its reactivity with deoxy- or carboxyhemoglobin A0. However, a subpopulation of this antiserum isolated by synthetic peptide affinity chromatography clearly distinguished between these two hemoglobin species. This subpopulation, designated alpha(129-141) anti-hemoglobin antibodies, represents less than 1% of the total anti-hemoglobin antibodies. They are nonprecipitating by Ouchterlony analysis, and fluorescence-quenching studies demonstrate the interaction of a single antibody binding site per hemoglobin dimer. These antibodies bind preferentially to carboxyhemoglobin with a median affinity constant of 5 X 10(8) M-1 compared to binding to deoxyhemoglobin with a binding affinity of less than 1 X 10(8) M-1. Furthermore, the presence of these antibodies in stoichiometric amounts increases the oxygen affinity of hemoglobin, and thus antibody and oxygen binding to hemoglobin can be considered as a linked function.
D000906:Antibodies; D000937:Antigen-Antibody Reactions; D002263:Carboxyhemoglobin / Q000276:immunology; D006441:Hemoglobin A / Q000276:immunology*; D006801:Humans; D005779:Immunodiffusion; D007122:Immunoelectrophoresis; D007700:Kinetics; D046911:Macromolecular Substances; D011233:Precipitin Tests; D011487:Protein Conformation; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics
D000906:Antibodies; D046911:Macromolecular Substances; D006441:Hemoglobin A; D002263:Carboxyhemoglobin