title: The binding of asparagine, glutamine and homoserine to human erythrocytes containing hemoglobins S and CS and to soluble hemoglobins S and CS.
abstract: Tritium labeled asparagine binds to oxyhemoglobin S and to a mixture of hemoglobins C and S in the molar ratio of 3.38:1 and 8.2:1 respectively. From the dialysis equilibrium studies it appears that labeled asparagine does not bind to oxy- or deoxy- hemoglobin A nor to deoxyhemoglobin S. The constant for equilibrium association of asparagine for oxyhemoglobin S is 7.38 x 10(7) M(-1) and for oxyhemoglobin CS 4.8 X 10(4) M(-1) at 23 degrees C. Tritium labeled asparagine is bound to oxyhemoglobin S and CS sufficiently strongly to prevent dissociation under the conditions of gel electrophoresis at pH 9.50. The protein with and without bound asparagine, glutamine or homoserine, is indistinguishable in molecular net charge and size by the criteria of quantitative polyacrylamide gel electrophoresis (PAGE). Also there were no significant differences in mobility between hemoglobin S and hemoglobin C in the presence and absence of asparagine, glutamine and homoserine as detectable in agar coated cellulose acetate electrophoresis at pH 6.3.
mesh_terms: D001216:Asparagine / Q000097:blood*; D001665:Binding Sites; D003201:Computers; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000378:metabolism*; D005973:Glutamine / Q000097:blood*; D006451:Hemoglobin, Sickle / Q000378:metabolism; D006454:Hemoglobins / Q000378:metabolism*; D006714:Homoserine / Q000097:blood*; D006801:Humans; D007700:Kinetics; D010108:Oxyhemoglobins / Q000378:metabolism*; D011485:Protein Binding
chemical_list: D006451:Hemoglobin, Sickle; D006454:Hemoglobins; D010108:Oxyhemoglobins; D005973:Glutamine; D006714:Homoserine; D001216:Asparagine