Mapping of the ligand-binding site on the b ' domain of human PDI: interaction with peptide ligands and the x-linker region
Byrne, Lee J., Sidhu, Ateesh, Wallis, A. Katrine, Ruddock, Lloyd W., Freedman, R. B., Howard, Mark J. and Williamson, Richard A.. (2009) Mapping of the ligand-binding site on the b ' domain of human PDI: interaction with peptide ligands and the x-linker region. Biochemical Journal, Vol.423 (No.2). pp. 209-217. ISSN 0264-6021Full text not available from this repository.
Official URL: http://dx.doi.org/10.1042/BJ20090565
PDI (protein disulfide-isomerase) catalyses the formation of native disulfide bonds of secretory proteins in the endoplasmic reticulum. PDI consists of four thioredoxin-like domains, of which two contain redox-active catalytic sites (a and a'), and two do not (b and b'). The b' domain is primarily responsible for substrate binding, although the nature and specificity of the substrate-binding site is still poorly understood. In the present study, we show that the W domain of human PDI is in conformational exchange, but that its structure is stabilized by the addition of peptide ligands or by binding the x-linker region. The location of the ligand-binding site in b' was mapped by NMR chemical shift perturbation and found to consist primarily of residues from the core beta-sheet and alpha-helices 1 and 3. This site is where the x-linker region binds in the X-ray structure of b'x and we show that peptide ligands can compete with x binding at this site. The finding that x binds in the principal ligand-binding site of W further supports the hypothesis that x functions to gate access to this site and so modulates PDI activity.
|Item Type:||Journal Article|
|Subjects:||Q Science > QD Chemistry|
|Divisions:||Faculty of Science > Life Sciences (2010- ) > Biological Sciences ( -2010)|
|Journal or Publication Title:||Biochemical Journal|
|Official Date:||15 October 2009|
|Number of Pages:||9|
|Page Range:||pp. 209-217|
|Access rights to Published version:||Restricted or Subscription Access|
|Funder:||Biotechnology and Biological Sciences Research Council (Great Britain) (BBSRC)|
|Grant number:||BB/D018072 (BBSRC)|
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