F
IPR000264

ALB/AFP/VDB

InterPro entry
Short nameALB/AFP/VDB
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
[1, 2, 3]
. 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
[4]
. It comprises three homologous domains that assemble to form a heart-shaped molecule
[4]
. Each domain is a product of two subdomains that possess common structural motifs
[4]
. 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
   |                 |       |     |              |               |
   +-----------------+       +-----+              +---------------+

References

1.Amphibian albumins as members of the albumin, alpha-fetoprotein, vitamin D-binding protein multigene family. Haefliger DN, Moskaitis JE, Schoenberg DR, Wahli W. J. Mol. Evol. 29, 344-54, (1989). View articlePMID: 2481749

2.Complete amino acid sequence of human vitamin D-binding protein (group-specific component): evidence of a three-fold internal homology as in serum albumin and alpha-fetoprotein. Schoentgen F, Metz-Boutigue MH, Jolles J, Constans J, Jolles P. Biochim. Biophys. Acta 871, 189-98, (1986). View articlePMID: 2423133

3.Afamin is a new member of the albumin, alpha-fetoprotein, and vitamin D-binding protein gene family. Lichenstein HS, Lyons DE, Wurfel MM, Johnson DA, McGinley MD, Leidli JC, Trollinger DB, Mayer JP, Wright SD, Zukowski MM. J. Biol. Chem. 269, 18149-54, (1994). View articlePMID: 7517938

4.Atomic structure and chemistry of human serum albumin. He XM, Carter DC. Nature 358, 209-15, (1992). View articlePMID: 1630489

GO terms

biological process

  • None

molecular function

  • None

Cross References

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