Hemoglobin

From IKE

Basics

• An oxygen-transport protein
• Accounts for 90% of the weight of a red blood cell
• Has a sigmoid-shaped dissociation curve
• Tetrameric structure that (in adults) consists of 2 α and 2 β chains
• 483 β chain, 201 α-1 chain, and 36 α-2 chain variations described

Diseases

• A lack of globin chain synthesis, or mutations in chromosomes 16 or 11 lead to thalassemia
• Point mutations in the beta gene leading to amino acid substitution of valine for glutamine lead to Sickle cell disease
• Lack of iron leads to iron deficiency anemia