PDBsum entry 4f5t

Transport protein

PDB id: 4f5t

Contents

Protein chain

583 a.a.

Ligands

ACT ×6

SO4 ×4

GOL ×8

Waters ×270

PDB id:

4f5t

Name:

Transport protein

Title:

Crystal structure of equine serum albumin

Structure:

Serum albumin. Chain: a. Fragment: unp residues 25-607

Source:

Equus caballus. Domestic horse,equine. Organism_taxid: 9796

Resolution:

2.32Å R-factor: 0.199 R-free: 0.259

Authors:

A.Bujacz,G.Bujacz

Key ref:

A.Bujacz (2012). Structures of bovine, equine and leporine serum albumin. Acta Crystallogr D Biol Crystallogr, 68, 1278-1289. PubMed id: 22993082

Date:

13-May-12 Release date: 03-Oct-12

Protein chain

P35747  (ALBU_HORSE) -  Albumin from Equus caballus

Seq: 607 a.a.

Struc: 583 a.a.

Acta Crystallogr D Biol Crystallogr 68:1278-1289 (2012)

PubMed id: 22993082

Structures of bovine, equine and leporine serum albumin.

A.Bujacz.

ABSTRACT

Serum albumin first appeared in early vertebrates and is present in the plasma of all mammals. Its canonical structure supported by a conserved set of disulfide bridges is maintained in all mammalian serum albumins and any changes in sequence are highly correlated with evolution of the species. Previous structural investigations of mammalian serum albumins have only concentrated on human serum albumin (HSA), most likely as a consequence of crystallization and diffraction difficulties. Here, the crystal structures of serum albumins isolated from bovine, equine and leporine blood plasma are reported. The structure of bovine serum albumin (BSA) was determined at 2.47 Å resolution, two crystal structures of equine serum albumin (ESA) were determined at resolutions of 2.32 and 2.04 Å, and that of leporine serum albumin (LSA) was determined at 2.27 Å resolution. These structures were compared in detail with the structure of HSA. The ligand-binding pockets in BSA, ESA and LSA revealed different amino-acid compositions and conformations in comparison to HSA in some cases; however, much more significant differences were observed on the surface of the molecules. BSA, which is one of the most extensively utilized proteins in laboratory practice and is used as an HSA substitute in many experiments, exhibits only 75.8% identity compared with HSA. The higher resolution crystal structure of ESA highlights the binding properties of this protein because it includes several bound compounds from the crystallization solution that provide additional structural information about potential ligand-binding pockets.