Hemorphin-7

YPWTQRF

Involved in oxygen transport from the lung to the various peripheral tissues.

Heterotetramer of two alpha chains and two beta chains in adult hemoglobin A (HbA).

Glucose reacts non-enzymatically with the N-terminus of the beta chain to form a stable ketoamine linkage. This takes place slowly and continuously throughout the 120-day life span of the red blood cell. The rate of glycation is increased in patients with diabetes mellitus.

Acetylated on Lys-60 Lys-83 and Lys-145 upon aspirin exposure. PubMed:16916647 reports the identification of HBB acetylated on Lys-145 in the cytosolic fraction of HeLa cells. This may results from a contamination of the sample. Mass Spectrometry: Mass=1310; Method=FAB; Range=33-42; Source=PubMed:1575724; .

Defects in HBB are the cause of beta-thalassemia [MIM:141900 604131]. The thalassemias are the most common monogenic diseases and occur mostly in Mediterranean and Southeast Asian populations. The hallmark of beta-thalassemia is an imbalance in globin-chain production in the adult HbA molecule. Absence of beta chain causes beta(0)-thalassemia while reduced amounts of detectable beta globin causes beta(+)-thalassemia. In the severe forms of beta-thalassemia the excess alpha globin chains accumulate in the developing erythroid precursors in the marrow. Their deposition leads to a vast increase in erythroid apoptosis that in turn causes ineffective erythropoiesis and severe microcytic hypochromic anemia. Clinically beta-thalassemia is divided into thalassemia major (transfusion dependent) thalassemia intermedia (of intermediate severity) and thalassemia minor (asymptomatic).

Defects in HBB are the cause of dominant beta-thalassemia inclusion body type [MIM:603902]. This form of beta-thalassemia is transmitted in an autosomal dominant fashion and is characterized by anemia enlargement of the spleen and gross abnormalities of the erythrocytes and their precursors.

Belongs to the globin family.