Interpreting Observations on Hemoglobin Cooperativity
Under appropriate conditions, hemoglobin dissociates into four subunits. The isolated alpha subunit binds oxygen, but the O2-saturation curve is hyperbolic rather than sigmoidal. In addition, the binding of oxygen to the isolated alpha subunit is not affected by H+, CO2, or BPG. What do these observations indicate about the source of cooperativity in hemoglobin?