The four canonical human albumins are arranged on chromosome 4 region 4q13.3 in a tandem manner.
Albumins found in animals can be divided into six subfamilies by phylogeny. The Vitamin-D binding proteins occupy families 1-3. The other albumins are mixed among each other in families 4-6. ECM1 is in family 6.
The 3D structure of human serum albumin has been determined by X-ray crystallography to a resolution of
2.5 ångströms (250 pm). Albumin is a 65-70 kDa protein.
Albumin comprises three homologous domains that assemble to form a heart-shaped protein. Each domain is a product of two subdomains that possess common structural motifs. The principal regions of ligand binding to human serum albumin are located in hydrophobic cavities in subdomains IIA and IIIA, which exhibit similar chemistry. Structurally, the serum albumins are similar, each domain containing five or six internal disulfide bonds.
Worldwide, certain traditional Chinese medicines contain wild bear bile, banned under CITES legislation. Dip sticks, similar to common pregnancy tests, have been developed to detect the presence of bear albumin in traditional medicine products, indicating that bear bile had been used in their creation.
Albumin is pronounced ; formed from Latin: albumen "(egg) white; dried egg white".
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