Reversible β-pleated sheet formation of a phosphorylated synthetic τ peptide

Lång, Emma; Szendrei, Gyorgyi I.; Elekes, I.; Lee, Virginia M.‐Y.; Ötvös, László

doi:10.1016/s0006-291x(05)80112-3

Cited by 22 publications

(10 citation statements)

References 23 publications

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“…Then, despite the fact that hCGRP-(19-37) is characterized by an a-helix-like spectrum, it seems more likely that a p-turn structure could be adopted in this fragment. Indeed, several CD studies reported that the spectra of various peptides containing a type MI1 p-turn resembles that obtained for the a-helical structure, with comparable spectral bands near 190, 208 and 222 nm (Tatham et al, 1990;Lang et al, 1992;Bush et al, 1978;Woody, 1974 and1985;Gierasch et al, 1981). Therefore, the most probable conformation found in the C-terminal segment of hCGRPa could correspond to a I/III /?…”

Section: Structural Characterization Of Various Fragments Of Hcgrpamentioning

confidence: 65%

Conformational characterization by circular‐dichroism spectroscopy of various fragments and analogs of calcitonin‐gene‐related peptide

Mimeault

St‐Pierre

Fournier

1993

European Journal of Biochemistry

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A conformational study by circular‐dichroism spectroscopy of calcitonin‐gene‐related peptide (CGRP) and related fragments and analogs was carried out in structure‐promoting solvent mixtures. The structural characterization of rat CGRPα and the two isoforms of human CGRP, α and β, revealed that these peptides possess very similar conformational features. The far‐ultraviolet circular‐dichroism spectra, in pure water, of human CGRPα, (hCGRPα), [Acm‐Cys2,7]hCGRPα, various fragments and analogs indicated that these peptides exhibited predominantly a random‐coil conformation. The addition of increasing concentrations of 1,1,1,3,3,3‐hexafluoro‐2‐propanol to the peptide solutions resulted in a transition from a random‐coil conformation to a stabilized α‐helical structure. The substantial loss of helical content measured with [Acm‐Cys2,7]hCGRPα, [Acm‐Cys2,7]hCGRP‐(1–24)‐CONH2 and hCGRP‐(8–37), compared to hCGRPα, suggested that the N‐terminal disulfide bridge of hCGRPα is essential for adopting a highly stabilized α‐helical conformation. Moreover, the lower helical content of hCGRP‐(8–37), as compared to [Acm‐Cys2,7]hCGRPα, as well as spectroscopic results measured with various fragments and analogs of hCGRP‐(8–37) revealed that N‐terminal residues found in the peptide segment 1–12 are important for the full conservation of the amphiphilic α‐helix. In addition, the similar α‐helical content of hCGRP‐(8–37) and hCGRP‐(8–18) indicated that the C‐terminal segment 19–37 is not essential for the stabilization of the α‐helix structure.

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Section: Structural Characterization Of Various Fragments Of Hcgrpamentioning

confidence: 65%

Conformational characterization by circular‐dichroism spectroscopy of various fragments and analogs of calcitonin‐gene‐related peptide

Mimeault

St‐Pierre

Fournier

1993

European Journal of Biochemistry

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“…25 The introduction of calcium to multi-phosphorylated peptides has been previously shown to induce β-sheet conformations; this mechanism may be relevant to the formation of neurofilament tangles in Alzheimer’s disease patients. 26–28 In caddisfly silk, this molecular arrangement possibly serves as a structural replacement for sheet-forming poly(A) and poly(GA) repeats in spider and silkworm silks. In this study, we put this hypothesis to test by using solid-state NMR and wide angle X-ray diffraction (WAXD) to probe the molecular structure of caddisfly larval silk.…”

Section: Introductionmentioning

confidence: 99%

β-Sheet Nanocrystalline Domains Formed from Phosphorylated Serine-Rich Motifs in Caddisfly Larval Silk: A Solid State NMR and XRD Study

et al. 2013

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Adhesive silks spun by aquatic caddisfly (order Trichoptera) larvae are used to build both intricate protective shelters and food harvesting nets underwater. In this study, we use 13C and 31P solid-state Nuclear Magnetic Resonance (NMR) and Wide Angle X-ray Diffraction (WAXD) as tools to elucidate molecular protein structure of caddisfly larval silk from the species Hesperophylax consimilis. Caddisfly larval silk is a fibroin protein based biopolymer containing mostly repetitive amino acid motifs. NMR and X-ray results provide strong supporting evidence for a structural model in which phosphorylated serine repeats (pSX)4 complex with divalent cations Ca2+ and Mg2+ to form rigid nanocrystalline β-sheet structures in caddisfly silk. 13C NMR data suggests that both phosphorylated serine and neighboring valine residues exist in a β-sheet secondary structure conformation while glycine and leucine residues common in GGX repeats likely reside in random coil conformations. Additionally, 31P chemical shift anisotropy (CSA) analysis indicates that the phosphates on phosphoserine residues are doubly ionized, and are charge-stabilized by divalent cations. Positively charged arginine side chains also likely play a role in charge stabilization. Finally, WAXD results finds that the silk is at least 7–8% crystalline, with β-sheet inter-plane spacings of 3.7 and 4.5 Å.

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“…This study does not negate the role of other factors, such as paired helical filaments (Perl, 1985), neurofibrillary tangles (Perl and Brody, 1980;Candy et al, 1992), and phosphorylated tau protein (Lee et al, 1991), which play a prominent role in the etiology of Alzheimer's disease. Evidence on synthetic model peptides from neurofilament proteins suggests that phosphorylaton of these proteins leads to their eventual deposition as paired helical filaments (Otvos et al, 1988;Lang et al, 1992;Holl6si et al, 1992;Fasman and Moore, 1994). It is possible that the A13+ implicated in the formation of these tangles and filaments could have indeed been carried by the circulating /31-40.…”

Section: Discussionmentioning

confidence: 99%

Interaction of synthetic Alzheimerβ-protein-derived analogs with aqueous aluminum: A low-field27Al NMR investigation

Vyas

Duffy

1995

J Protein Chem

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Synthetic peptides corresponding to the soluble Alzheimer beta-protein, i.e., beta 1-40 and beta 6-25, were utilized to investigate the association of aluminum using low-field 27Al nuclear magnetic resonance (NMR) spectroscopy and reversed-phase high-performance liquid chromatography (RP-HPLC). Addition of beta 1-40 or beta 6-25 to aqueous Al3+ gives rise to a 27Al NMR signal corresponding to the association of Al3+ with the peptides; this effect is not easily reversed by EDTA. Based on the relative intensity of the Al(3+)-peptide signal between pH 4 and 6, there are at least 4 Al3+ ions associated with each peptide molecule. Microheterogeneity is observed with RP-HPLC on incubating solutions of Al3+ with beta 1-40 and beta 6-25. The 27Al NMR spectra of chromatographically pure fractions of beta 1-40 and beta 6-25 indicate that the peptide-associated Al3+ is released below pH 3.5. We propose that soluble beta 1-40 provides an anchor for Al3+ to bind, eventually leading to an increased deposition of amyloid in the Alzheimer brain.

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Reversible β-pleated sheet formation of a phosphorylated synthetic τ peptide

Cited by 22 publications

References 23 publications

Conformational characterization by circular‐dichroism spectroscopy of various fragments and analogs of calcitonin‐gene‐related peptide

Conformational characterization by circular‐dichroism spectroscopy of various fragments and analogs of calcitonin‐gene‐related peptide

β-Sheet Nanocrystalline Domains Formed from Phosphorylated Serine-Rich Motifs in Caddisfly Larval Silk: A Solid State NMR and XRD Study

Interaction of synthetic Alzheimerβ-protein-derived analogs with aqueous aluminum: A low-field27Al NMR investigation

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