Hemoglobin subunit beta (beta globin, β-globin, haemoglobin beta, hemoglobin beta) is a globin protein, coded for by the HBB gene, which along with alpha globin , makes up the most common form of haemoglobin in adult humans, hemoglobin A (HbA). [5]

May 1, 2023 · HbA, the most common adult form of hemoglobin, comprises two alpha and two beta-globin subunits. Inversely to HbF, HbA production explodes after birth and ultimately makes up 95-98% of hemoglobin in adults.

The amino acid sequences of the globin subunits usually differ between species, with the difference growing with evolutionary distance. For example, the most common hemoglobin sequences in humans, bonobos and chimpanzees are completely identical, with exactly the same alpha and beta globin protein chains.

Although the genes in and around the α-like globin gene complex are relatively stable, the β-like globin gene clusters are more dynamic, showing evidence of transposition to a new locus and frequent lineage-specific expansions and deletions.

Jan 15, 2024 · The main difference between alpha and beta chains in hemoglobin is that alpha-chain hemoglobin contains 141 amino acids, whereas beta-chain hemoglobin contains 146 amino acids. Alpha and beta chains in hemoglobin are the two chain types that occur in hemoglobin.

Aug 25, 2023 · Adult hemoglobin has two alpha subunits (α1 and α2) and two beta subunits (β1 and β2) combined as two αβ dimers that are arranged around 2-fold axis symmetry. Each subunit has a heme attached to the globin protein. In fetal hemoglobin, the beta subunits are replaced by gamma subunits (γ1 and γ2).

Apr 14, 2002 · The combination of two alpha genes and two gamma genes forms fetal hemoglobin, or hemoglobin F. Around the time of birth, the production of gamma globin declines in concert with a rise in beta globin synthesis.

In most vertebrates, Hb is a tetramer, consisting of two α-subunits (α 1 and α 2) and two β-subunits (β 1 and β 2) that are structurally similar and about the same size (Fig. 14.2a).

In adults, hemoglobin typically consists of four protein subunits: two subunits of beta-globin and two subunits of a protein called alpha-globin, which is produced from another gene called HBA.

An alteration to the alpha or beta globin will result in an abnormal hemoglobin. What is the function of hemoglobin? The major role of hemoglobin is to carry oxygen from the lungs to the tissues and return carbon dioxide (CO 2) from the tissue to the lungs. It is the oxygen carrying component of RBCs.