title: Huntingtin spheroids and protofibrils as precursors in polyglutamine fibrilization.
abstract: The pathology of Huntington's disease is characterized by neuronal degeneration and inclusions containing N-terminal fragments of mutant huntingtin (htt). To study htt aggregation, we examined purified htt fragments in vitro, finding globular and protofibrillar intermediates participating in the genesis of mature fibrils. These intermediates were high in beta-structure. Furthermore, Congo Red, a dye that stains amyloid fibrils, prevented the assembly of mutant htt into mature fibrils, but not the formation of protofibrils. Other proteins capable of forming ordered aggregates, such as amyloid beta and alpha-synuclein, form similar intermediates, suggesting that the mechanisms of mutant htt aggregation and possibly htt toxicity may overlap with other neurodegenerative disorders.
authors.affiliation: Division of Neurobiology, Department of Psychiatry, Johns Hopkins University School of Medicine, 615 Ross Research Building, 720 Rutland Avenue, Baltimore, MD 21205, USA.
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Poirier
authors.forename: Huilin
authors.initials: H
authors.lastname: Li
authors.forename: Jed
authors.initials: J
authors.lastname: Macosko
authors.forename: Shuowei
authors.initials: S
authors.lastname: Cai
authors.forename: Mario
authors.initials: M
authors.lastname: Amzel
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Ross
mesh_terms: D000345:Affinity Labels; D008854:Microscopy, Electron; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000235:genetics / Q000648:ultrastructure; D009687:Nuclear Proteins / Q000737:chemistry* / Q000235:genetics / Q000648:ultrastructure; D010455:Peptides / Q000737:chemistry*; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000345:Affinity Labels; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D010455:Peptides; D011994:Recombinant Proteins; C097188:polyglutamine