title: Factors that drive peptide assembly from native to amyloid structures: experimental and theoretical analysis of [leu-5]-enkephalin mutants.
abstract: Five different mutants of [Leu-5] Enkephalin YGGFL peptide have been investigated for fibril formation propensities. The early oligomer structures have been probed with a combination of ion-mobility mass spectrometry and computational modeling. The two peptides YVIFL and YVVFL form oligomers and amyloid-like fibrils. YVVFV shows an early stage oligomer distribution similar to those of the previous two, but amyloid-like aggregates are less abundant. Atomic resolution X-ray structures of YVVFV show two different modes of interactions at the dry interface between steric zippers and pairs of antiparallel β-sheets, but both are less favorable than the packing motif found in YVVFL. Both YVVFV and YVVFL can form a Class 6 steric zipper. However, in YVVFV, the strands between mating sheets are parallel to each other and in YVVFL they are antiparallel. The overall data highlight the importance of structurally characterizing high order oligomers within oligomerization pathways in studies of nanostructure assembly.
authors.affiliation: Department of Chemistry and Biochemistry and ‡Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California , Santa Barbara, California 93106, United States.
authors.forename: Thanh D
authors.initials: TD
authors.lastname: Do
authors.forename: Nichole E
authors.initials: NE
authors.lastname: LaPointe
authors.forename: Smriti
authors.initials: S
authors.lastname: Sangwan
authors.forename: David B
authors.initials: DB
authors.lastname: Teplow
authors.forename: Stuart C
authors.initials: SC
authors.lastname: Feinstein
authors.forename: Michael R
authors.initials: MR
authors.lastname: Sawaya
authors.forename: David S
authors.initials: DS
authors.lastname: Eisenberg
authors.forename: Michael T
authors.initials: MT
authors.lastname: Bowers
mesh_terms: D000595:Amino Acid Sequence; D000682:Amyloid / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004745:Enkephalins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D013058:Mass Spectrometry; D046529:Microscopy, Electron, Transmission; D056004:Molecular Dynamics Simulation; D049329:Nanostructures / Q000737:chemistry; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary
chemical_list: D000682:Amyloid; D004745:Enkephalins