Hemoglobin, alpha 2

Hemoglobin, alpha 2 (also known as HBA2) is a protein that in humans is encoded by the HBA2 gene. It is one of the two alpha-globin chains of hemoglobin, the oxygen-carrying molecule found in red blood cells.

Structure

The HBA2 gene provides instructions for making a component of hemoglobin. Hemoglobin consists of four protein subunits: two alpha-globin and two beta-globin. Each of these subunits is attached to a molecule called heme, which can bind to one molecule of oxygen. The binding of oxygen by heme is what allows hemoglobin to carry oxygen in the blood.

Function

The primary function of the alpha 2 hemoglobin is to carry oxygen from the lungs to the body's tissues and to return carbon dioxide from the tissues back to the lungs. This is facilitated by the heme group, which is capable of binding and releasing oxygen molecules.

Clinical significance

Mutations in the HBA2 gene can cause alpha thalassemia, a blood disorder that reduces the production of hemoglobin. Depending on the number and type of mutations, alpha thalassemia can range from mild to severe.

See also

• Hemoglobin
• Alpha-globin
• Beta-globin
• Heme
• Thalassemia