title: How post-translational modifications influence amyloid formation: a systematic study of phosphorylation and glycosylation in model peptides.
abstract: A reciprocal relationship between phosphorylation and O-glycosylation has been reported for many cellular processes and human diseases. The accumulated evidence points to the significant role these post-translational modifications play in aggregation and fibril formation. Simplified peptide model systems provide a means for investigating the molecular changes associated with protein aggregation. In this study, by using an amyloid-forming model peptide, we show that phosphorylation and glycosylation can affect folding and aggregation kinetics differently. Incorporation of phosphoserines, regardless of their quantity and position, turned out to be most efficient in preventing amyloid formation, whereas O-glycosylation has a more subtle effect. The introduction of a single beta-galactose does not change the folding behavior of the model peptide, but does alter the aggregation kinetics in a site-specific manner. The presence of multiple galactose residues has an effect similar to that of phosphorylation.
authors.affiliation: Institut für Chemie und Biochemie, Freie Universität Berlin, Takustrasse 3, 14195 Berlin, Germany.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Broncel
authors.forename: Jessica A
authors.initials: JA
authors.lastname: Falenski
authors.forename: Sara C
authors.initials: SC
authors.lastname: Wagner
authors.forename: Christian P R
authors.initials: CP
authors.lastname: Hackenberger
authors.forename: Beate
authors.initials: B
authors.lastname: Koksch
mesh_terms: D000595:Amino Acid Sequence; D000682:Amyloid / Q000737:chemistry*; D006020:Glycopeptides / Q000737:chemistry*; D006031:Glycosylation; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D017433:Protein Structure, Secondary
chemical_list: D000682:Amyloid; D006020:Glycopeptides