title: Heme Stabilization of α-Synuclein Oligomers during Amyloid Fibril Formation.
abstract: α-Synuclein (αSyn), which forms amyloid fibrils, is linked to the neuronal pathology of Parkinson's disease, as it is the major fibrillar component of Lewy bodies, the inclusions that are characteristic of the disease. Oligomeric structures, common to many neurodegenerative disease-related proteins, may in fact be the primary toxic species, while the amyloid fibrils exist either as a less toxic dead-end species or even as a beneficial mechanism for clearing damaged proteins. To alter the progression of the aggregation and gain insights into the prefibrillar structures, we determined the effect of heme on αSyn oligomerization by several different techniques, including native (nondenaturing) polyacrylamide gel electrophoresis, thioflavin T fluorescence, transmission electron microscopy, atomic force microscopy, circular dichroism, and membrane permeation using a calcein release assay. During aggregation, heme is able to bind the αSyn in a specific fashion, stabilizing distinct oligomeric conformations and promoting the formation of αSyn into annular structures, thereby delaying and/or inhibiting the fibrillation process. These results indicate that heme may play a regulatory role in the progression of Parkinson's disease; in addition, they provide insights into how the aggregation process may be altered, which may be applicable to the understanding of many neurodegenerative diseases.
authors.affiliation: †Department of Physiology and Biophysics, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York 10461, United States.
authors.forename: Eric Y
authors.initials: EY
authors.lastname: Hayden
authors.affiliation: ‡Department of Chemistry, Hunter College and Graduate Center, The City University of New York, New York, New York 10021, United States.
authors.forename: Prerna
authors.initials: P
authors.lastname: Kaur
authors.affiliation: §Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106, United States.
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Williams
authors.affiliation: ‡Department of Chemistry, Hunter College and Graduate Center, The City University of New York, New York, New York 10021, United States.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Matsui
authors.affiliation: †Department of Physiology and Biophysics, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York 10461, United States.
authors.forename: Syun-Ru
authors.initials: SR
authors.lastname: Yeh
authors.affiliation: †Department of Physiology and Biophysics, Albert Einstein College of Medicine of Yeshiva University, Bronx, New York 10461, United States.
authors.forename: Denis L
authors.initials: DL
authors.lastname: Rousseau
mesh_terms: D000682:Amyloid / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D006418:Heme / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D010300:Parkinson Disease / Q000378:metabolism; D066263:Protein Aggregation, Pathological / Q000378:metabolism; D055503:Protein Multimerization; D051844:alpha-Synuclein / Q000737:chemistry* / Q000378:metabolism
chemical_list: D000682:Amyloid; D051844:alpha-Synuclein; D006418:Heme