A5103025260- Organic Chemistry Cycloaddition Reactions
- Protein Structure and Dynamics
- Alzheimer's disease research and treatments
- Enzyme Structure and Function
- Synthesis and Reactivity of Sulfur-Containing Compounds
- Sulfur-Based Synthesis Techniques
- Proteins in Food Systems
- Chemical Synthesis and Reactions
- Heat shock proteins research
- Chemical Reaction Mechanisms
- Organic and Inorganic Chemical Reactions
- Glycosylation and Glycoproteins Research
- Supramolecular Self-Assembly in Materials
- Organoselenium and organotellurium chemistry
- Enzyme Production and Characterization
- Porphyrin and Phthalocyanine Chemistry
- Synthesis of heterocyclic compounds
- Synthesis and Characterization of Heterocyclic Compounds
- Prion Diseases and Protein Misfolding
- Organic and Molecular Conductors Research
- Oxidative Organic Chemistry Reactions
- Molecular spectroscopy and chirality
- Synthesis and Catalytic Reactions
- Structural and Chemical Analysis of Organic and Inorganic Compounds
- Organophosphorus compounds synthesis
Kyoto Pharmaceutical University
2008-2024
Kyoto University
2014-2024
University of Tehran
2023
Shiraz University
2023
Henan University
2023
Johns Hopkins University
2023
Tokyo Metropolitan Tama-Hokubu Medical Center
2022
Osaka University
1998-2014
Tottori University
2014
Protein Research Foundation
1999-2014
Among various alcohols, those substituted with fluorine, such as 2,2,2-trifluoroethanol (TFE) or 3,3,3,3',3',3'-hexafluoro-2-propanol (HFIP), have a marked potential to induce the formation of α-helical structures in peptides and denature native proteins. However, mechanism by which these alcohols exert their effects is unknown. Melittin, bee venom peptide, unfolded absence alcohol, but transformed an structure upon addition alcohols. On other hand, β-lactoglobulin, predominantly β-sheet...
Unfolded states of ribonuclease A were used to investigate the effects macromolecular crowding on compactness and protein folding. The extent folding measured by circular dichroism spectroscopy, fluorescence correlation NMR spectroscopy in presence polyethylene glycol (PEG) or Ficoll as agent. unfolded state RNase a 2.4 M urea solution at pH 3.0 became native conformation addition 35% PEG 20000 70. In addition, inert macromolecule investigated using Fluorescence-labeled test macromolecule....
Abstract Using heteronuclear NMR spectroscopy, we studied the solution structure and dynamics of bovine β‐lactoglobulin A at pH 2.0 45 °C, where protein exists as a monomeric native state. The structure, comprising an eight‐stranded continuous antiparallel β‐barrel one major α‐helix, is similar to X‐ray dimeric obtained 6.2, including β I strand that forms dimer interface loop EF serves lid interior hydrophobic hole. { 1 H}‐ 15 N NOE revealed f , g H strands buried under α‐helix are rigid on...
It is widely accepted that the conversion of soluble, nontoxic amyloid β-protein (Aβ) monomer to aggregated toxic Aβ rich in β-sheet structures central development Alzheimer's disease. However, mechanism abnormal aggregation vivo not well understood. We have proposed ganglioside clusters lipid rafts mediate formation fibrils by Aβ, toxicity and physicochemical properties which are different from those amyloids formed solution. In this paper, Aβ-(1–40) fibrillizes raftlike bilayers composed...
Ubiquitin is known to be one of the most soluble and stably folded intracellular proteins, but it often found in inclusion bodies associated with various diseases including neurodegenerative disorders cancer. To gain insight into this contradictory behaviour, we have examined physicochemical properties ubiquitin its polymeric chains that lead aggregate formation. We find folding stability unexpectedly decreases increasing chain length, resulting formation amyloid-like fibrils. Furthermore,...
Abstract M161Ag is a 43-kDa surface lipoprotein of Mycoplasma fermentans, serving as potent cytokine inducer for monocytes/macrophages, maturing dendritic cells (DCs), and activating host complement on affected cells. It possesses unique N-terminal lipo-amino acid, S-diacylglyceryl cysteine. The 2-kDa macrophage-activating lipopeptide-2 (MALP-2), recently identified ligand Toll-like receptor 2 (TLR2), derived from M161Ag. In this study, we structural motifs sustaining the functions using...
Whereas the salt-dependent conformational transition of acid-denatured horse ferricytochrome c at pH 2 is approximated by a two-state mechanism from acid-unfolded state to molten globule [Kataoka, M., Hagihara, Y., Mihara, K., & Goto, Y. (1993) J. Mol. Biol. 229, 591-596], corresponding in D2O has been proposed involve noncompact, alpha-helical intermediate (the pre-molten state) [Jeng, M.-F., Englander, S. W. (1991) 221, 1045-1061]. To examine difference transitions, we carried out HCl and...
Whereas bovine β-lactoglobulin is a predominantly β-sheet protein, it has marked α-helical preference and can be considered to useful model of the α → β transition, key issue for understanding folding biological function number proteins. In order understand mechanism backbone structures recombinant A in native state highly helical induced by 2,2,2-trifluoroethanol were characterized 1H, 13C 15N multidimensional NMR spectroscopy. Overall, secondary similar those crystal structure. On other...
Ultraviolet photoelectron spectroscopy (UPS) has been applied to the investigation of electronic structure oligothiophenes with 4–8 thiophene rings. In a series α-linked oligomers (αn n being number rings), systematic evolution π band is observed. Several peaks which correspond are observed in region 0.7–3 eV below Fermi level (EF), and bandwidth becomes broader increasing n. The nonbonding at 3.5 EF its energy almost independent units. UPS spectra α7 α8 fairly similar polythiophene, showing...
beta(2)-Microglobulin (beta2-m) is a major component of dialysis-related amyloid fibrils. Although recombinant beta2-m forms needle-like fibrils by in vitro extension reaction at pH 2.5, reduced beta2-m, which the intrachain disulfide bond reduced, cannot form typical Instead, thinner and flexible filaments are formed, as shown atomic force microscopy images. To clarify role fibril formation, we characterized conformations oxidized (intact) acid-denatured state well native 6.5, heteronuclear...
The conversion of the soluble, nontoxic amyloid-beta (Abeta) peptide into an aggregated, toxic form rich in beta-sheets is considered a key step development Alzheimer's disease. Whereas growing evidence indicates that Abeta amyloid fibrils consist in-register parallel beta-sheets, little known about structure soluble oligomeric intermediates because their transient nature. To understand mechanism by which form, especially initial "nucleus" intermediates, we prepared covalently linked dimeric...
The abnormal aggregation of amyloid β-protein (Aβ) is considered central in the pathogenesis Alzheimer's disease. We focused on membrane-mediated amyloidogenesis and found that fibrils formed monosialoganglioside GM1 clusters were more toxic than those aqueous solution. In this study, we investigated structure by Aβ-(1–40) detail comparison with less-toxic contain in-resister parallel β-sheets, whereas unknown. Atomic force microscopy revealed had a flat, tape-like morphology composed single...
beta(2)-Microglobulin (beta2M), the light chain of type I major histocompatibility complex, is a component dialysis-related amyloid fibrils. beta2M in native state has typical immunoglobulin fold with buried intrachain disulfide bond. The conformation and stability recombinant which bond was reduced were studied by CD, tryptophan fluorescence, one-dimensional NMR. absence denaturant at pH 8.5 similar to that intact protein unless thiol groups modified. However, reduction decreased as...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIntermediate conformational states of apocytochrome cDaizo Hamada, Masaru Hoshino, Mikio Kataoka, Anthony L. Fink, and Yuji GotoCite this: Biochemistry 1993, 32, 39, 10351–10358Publication Date (Print):October 5, 1993Publication History Published online1 May 2002Published inissue 5 October 1993https://pubs.acs.org/doi/10.1021/bi00090a010https://doi.org/10.1021/bi00090a010research-articleACS PublicationsRequest reuse permissionsArticle...
A key pathological event in dialysis-related amyloidosis is the fibril formation of beta(2)-microglobulin (beta 2-m). Because beta 2-m does not form fibrils vitro, except under acidic conditions, predisposing factors that may drive at physiological pH have been focus much attention. One factor be implicated Cu(2+) binding, which destabilizes native state and thus stabilizes amyloid precursor. To address Cu(2+)-induced destabilization atomic level, we studied changes conformational dynamics...
A detailed analysis of the NMR spectra amyloid-β (Aβ) peptide revealed a decrease in signal intensity at higher temperature, due to reversible conformational change molecule. Although peak did not depend on concentrations, region from D23 A30 depended significantly temperature. During early stages Aβ aggregation, each molecule might adopt transiently turn conformation around D23–A30, which converts mutually with random coil. Stabilization by further and/or molecular association would lead...
The conversion of soluble, nontoxic amyloid β-proteins (Aβ) to aggregated, toxic forms rich in β-sheets is considered be a key step the development Alzheimer's disease. Accumulating evidence suggests that lipid-protein interactions play crucial role aggregation amyloidogenic proteins like Aβ. Our group has previously reported fibrils Aβ formed on membranes containing clusters GM1 ganglioside (M-fibrils) exhibit greater cytotoxicity than aqueous solution (W-fibrils) [ Okada ( 2008 ) J. Mol....