1m25

From Proteopedia

proteopedia linkproteopedia link

Template:STRUCTURE 1m25

STRUCTURE OF SYNTHETIC 26-MER PEPTIDE CONTAINING 145-169 SHEEP PRION PROTEIN SEGMENT AND C-TERMINAL CYSTEINE IN TFE SOLUTION

Overview

The conformational conversion of the nonpathogenic "cellular" prion isoform into a pathogenic "scrapie" protease-resistant isoform is a fundamental event in the onset of transmissible spongiform encephalopathies (TSE). During this pathogenic conversion, helix H1 and its two flanking loops of the normal prion protein are thought to undergo a conformational transition into a beta-like structure. A peptide spanning helix H1 and beta-strand S2 (residues 142-166 in human numbering) was studied by circular dichroism and nuclear magnetic resonance spectroscopies. This peptide in aqueous solution, in contrast to many prion fragments studied earlier (1) is highly soluble and (2) does not aggregate until the millimolar concentration range, and (3) exhibits an intrinsic propensity to a beta-hairpin-like conformation at neutral pH. We found that this peptide can also fold into a helix H1 conformation when dissolved in a TFE/PB mixture. The structures of the peptide calculated by MD showed solvent-dependent internal stabilizing forces of the structures and evidenced a higher mobility of the residues following the end of helix H1. These data suggest that the molecular rearrangement of this peptide in region 152-156, particularly in position 155, could be associated with the pathogenic conversion of the prion protein.

About this Structure

1M25 is a Single protein structure. Full crystallographic information is available from OCA.

Reference

Possible role of region 152-156 in the structural duality of a peptide fragment from sheep prion protein., Megy S, Bertho G, Kozin SA, Debey P, Hoa GH, Girault JP, Protein Sci. 2004 Dec;13(12):3151-60. Epub 2004 Nov 10. PMID:15537751 Page seeded by OCA on Sat May 3 00:32:39 2008