Family

Serum albumin/Alpha-fetoprotein (IPR021177)

Short name: Serum_albumin/AFP

Family relationships

Description

A number of serum transport proteins are known to be evolutionarily related, including albumin, alpha-fetoprotein, vitamin D-binding protein and afamin [PMID: 2481749, PMID: 2423133, PMID: 7517938]. Albumin is the main protein of plasma; it binds water, cations (such as Ca2+, Na+ and K+), fatty acids, hormones, bilirubin and drugs - its main function is to regulate the colloidal osmotic pressure of blood. Alphafeto- protein (alpha-fetoglobulin) is a foetal plasma protein that binds various cations, fatty acids and bilirubin. Vitamin D-binding protein binds to vitamin D and its metabolites, as well as to fatty acids. The biological role of afamin (alpha-albumin) has not yet been characterised. The 3D structure of human serum albumin has been determined by X-ray crystallography to a resolution of 2.8A [PMID: 1630489]. It comprises three homologous domains that assemble to form a heart-shaped molecule [PMID: 1630489]. Each domain is a product of two subdomains that possess common structural motifs [PMID: 1630489]. 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 disulphide bonds, as shown schematically below:

                    +---+          +----+                        +-----+
                    |   |          |    |                        |     |
 xxCxxxxxxxxxxxxxxxxCCxxCxxxxCxxxxxCCxxxCxxxxxxxxxCxxxxxxxxxxxxxxCCxxxxCxxxx
   |                 |       |     |              |               |
   +-----------------+       +-----+              +---------------+

This entry represents the serum albumin and the Alpha-fetoprotein.

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

No terms assigned in this category.

Cellular Component

GO:0005615 extracellular space

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PIRSF