2kkg
From Proteopedia
NMR structure of the octarepeat region of prion protein bound to pentosan polysulfate
Structural highlights
Disease[PRIO_MESAU] Note=Found in high quantity in the brain of humans and animals infected with degenerative neurological diseases such as kuru, Creutzfeldt-Jakob disease (CJD), Gerstmann-Straussler syndrome (GSS), scrapie, bovine spongiform encephalopathy (BSE), transmissible mink encephalopathy (TME), etc. Function[PRIO_MESAU] May play a role in neuronal development and synaptic plasticity. May be required for neuronal myelin sheath maintenance. May play a role in iron uptake and iron homeostasis. Soluble oligomers are toxic to cultured neuroblastoma cells and induce apoptosis (in vitro). Association with GPC1 (via its heparan sulfate chains) targets PRNP to lipid rafts. Also provides Cu(2+) or ZN(2+) for the ascorbate-mediated GPC1 deaminase degradation of its heparan sulfate side chains (By similarity).[1] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe intrinsically disordered amino-proximal domain of hamster prion protein (PrP) contains four copies of a highly conserved octapeptide sequence, PHGGGWGQ, that is flanked by two polycationic residue clusters. This N-terminal domain mediates the binding of sulfated glycans, which can profoundly influence the conversion of PrP to pathological forms and the progression of prion disease. To investigate the structural consequences of sulfated glycan binding, we performed multidimensional heteronuclear ((1)H, (13)C, (15)N) NMR (nuclear magnetic resonance), circular dichroism (CD), and fluorescence studies on hamster PrP residues 23-106 (PrP 23-106) and fragments thereof when bound to pentosan polysulfate (PPS). While the majority of PrP 23-106 remain disordered upon PPS binding, the octarepeat region adopts a repeating loop-turn structure that we have determined by NMR. The beta-like turns within the repeats are corroborated by CD data demonstrating that these turns are also present, although less pronounced, without PPS. Binding to PPS exposes a hydrophobic surface composed of aligned tryptophan side chains, the spacing and orientation of which are consistent with a self-association or ligand binding site. The unique tryptophan motif was probed by intrinsic tryptophan fluorescence, which displayed enhanced fluorescence of PrP 23-106 when bound to PPS, consistent with the alignment of tryptophan side chains. Chemical-shift mapping identified binding sites on PrP 23-106 for PPS, which include the octarepeat histidine and an N-terminal basic cluster previously linked to sulfated glycan binding. These data may in part explain how sulfated glycans modulate PrP conformational conversions and oligomerizations. Structure of the flexible amino-terminal domain of prion protein bound to a sulfated glycan.,Taubner LM, Bienkiewicz EA, Copie V, Caughey B J Mol Biol. 2010 Jan 22;395(3):475-90. Epub 2009 Nov 10. PMID:19913031[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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