Which hemoglobin variant shows the slowest mobility at pH 8.6?

In the context of hemoglobin variants and their behavior during electrophoresis, hemoglobin C is known for displaying the slowest mobility at a neutral pH, such as pH 8.6. This is largely due to the specific amino acid substitutions present in the hemoglobin C variant. Hemoglobin C has a glutamic acid residue replaced by lysine, which alters its overall charge and decreases its mobility when subjected to an electric field.

When proteins are subjected to electrophoresis, the movement of each hemoglobin variant depends on its net charge and structure. At pH 8.6, hemoglobin A and hemoglobin S will move more quickly because they possess different charge properties compared to hemoglobin C. Hemoglobin A has a higher positive charge, which facilitates faster movement, while hemoglobin S, which is associated with sickle cell anemia, has distinct charge characteristics that allow it to migrate more rapidly than hemoglobin C but slower than hemoglobin A.

Hemoglobin A2, while also moving at a slower rate compared to hemoglobin A, does not exhibit the same degree of decreased mobility as hemoglobin C. Therefore, hemoglobin C’s unique charge properties lead it to migrate slowest during electrophoresis at pH