Phosphorylation of an alpha-synuclein peptide fragment enhances metal binding.
By using Tb3+ as a luminescent probe, we demonstrate that the phosphorylation state of a 14-residue peptide fragment of alpha-synuclein, a protein implicated in Parkinson's Disease, dramatically affects the metal ion affinity of the peptide. Whereas the unphosphorylated peptide and its phosphoserine analogue show weak Tb3+ binding, its phosphotyrosine analogue shows tight 1:1 binding as well as 2:1 and 3:1 Tb:peptide adducts. Our data suggest that the phosphorylated amino acid must be appropriately positioned among additional ligating residues to establish this phosphorylation-dependent metal binding.
Liu
Lucy L
LL
Department of Chemistry, Duke University, P.O. Box 90346, Durham, North Carolina 27708, USA.
Franz
Katherine J
KJ
D000595:Amino Acid Sequence; D006801:Humans; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000378:metabolism*; D010446:Peptide Fragments / Q000737:chemistry* / Q000378:metabolism*; D010766:Phosphorylation; D010768:Phosphoserine / Q000378:metabolism; D019000:Phosphotyrosine / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D051843:Synucleins; D013725:Terbium / Q000378:metabolism*; D017186:Titrimetry; D051844:alpha-Synuclein
D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; C497604:SNCA protein, human; D051843:Synucleins; D051844:alpha-Synuclein; D013725:Terbium; D010768:Phosphoserine; D019000:Phosphotyrosine