Lamellar mesoscopic organization of supramolecular polymers: a necessary pre-ordering secondary structure

The objectives of the study were to use synchrotron Fourier transform infrared microspectroscopy (S-FTIR) as a novel approach to: (1) reveal ultra-structural chemical features of protein secondary structures of flaxseed tissues affected by variety (golden and brown) and heat processing (raw and roasted), and (2) quantify protein secondary structures using Gaussian and Lorentzian methods of multi-component peak modeling. By using multi-component peak modeling at protein amide I region of 1700–1620 cm-1, the results showed that the golden flaxseed contained relatively higher percentage of α-helix (47.1 vs. 36.9%), lower percentage of β-sheet (37.2 vs. 46.3%) and higher (P < 0.05) ratio of α-helix to β-sheet than the brown flaxseed (1.3 vs. 0.8). The roasting reduced (P < 0.05) percentage of α-helix (from 47.1 to 36.1%), increased percentage of β-sheet (from 37.2 to 49.8%) and reduced α-helix to β-sheet ratio (1.3 to 0.7) of the golden flaxseed tissues. However, the roasting did not affect percentage and ratio of α-helix and β-sheet in the brown flaxseed tissue. No significant differences were found in quantification of protein secondary structures between Gaussian and Lorentzian methods. These results demonstrate the potential of highly spatially resolved S-FTIR to localize relatively pure protein in the tissue and reveal protein secondary structures at a cellular level. The results indicated relative differences in protein secondary structures between flaxseed varieties and differences in sensitivities of protein secondary structure to the heat processing. Further study is needed to understand the relationship between protein secondary structure and protein digestion and utilization of flaxseed and to investigate whether the changes in the relative amounts of protein secondary structures are primarily responsible for differences in protein availability. Key words: Synchrotron, FTIR microspectrosopy, flaxseeds, intrinsic structural matrix, protein secondary structures, protein nutritive value

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Two-Dimensional Infrared Spectroscopy of Antiparallel β-Sheet Secondary Structure

Journal of the American Chemical Society ◽

10.1021/ja049811j ◽

2004 ◽

Vol 126 (25) ◽

pp. 7981-7990 ◽

Cited By ~ 169

Author(s):

Nurettin Demirdöven ◽

Christopher M. Cheatum ◽

Hoi Sung Chung ◽

Munira Khalil ◽

Jasper Knoester ◽

...

Keyword(s):

Infrared Spectroscopy ◽

Secondary Structure ◽

Two Dimensional ◽

Two Dimensional Infrared Spectroscopy ◽

Β Sheet

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(De)stabilization of Alpha-Synuclein Fibrillary Aggregation by Charged and Uncharged Surfactants

International Journal of Molecular Sciences ◽

10.3390/ijms222212509 ◽

2021 ◽

Vol 22 (22) ◽

pp. 12509

Author(s):

Joana Angélica Loureiro ◽

Stéphanie Andrade ◽

Lies Goderis ◽

Ruben Gomez-Gutierrez ◽

Claudio Soto ◽

...

Keyword(s):

Secondary Structure ◽

Hydrophobic Interactions ◽

Neurodegenerative Disorder ◽

Sodium Dodecyl ◽

Lewy Bodies ◽

Alpha Synuclein ◽

Cetyltrimethylammonium Chloride ◽

Α Helix ◽

Β Sheet

Parkinson’s disease (PD) is the second most common neurodegenerative disorder. An important hallmark of PD involves the pathological aggregation of proteins in structures known as Lewy bodies. The major component of these proteinaceous inclusions is alpha (α)-synuclein. In different conditions, α-synuclein can assume conformations rich in either α-helix or β-sheets. The mechanisms of α-synuclein misfolding, aggregation, and fibrillation remain unknown, but it is thought that β-sheet conformation of α-synuclein is responsible for its associated toxic mechanisms. To gain fundamental insights into the process of α-synuclein misfolding and aggregation, the secondary structure of this protein in the presence of charged and non-charged surfactant solutions was characterized. The selected surfactants were (anionic) sodium dodecyl sulphate (SDS), (cationic) cetyltrimethylammonium chloride (CTAC), and (uncharged) octyl β-D-glucopyranoside (OG). The effect of surfactants in α-synuclein misfolding was assessed by ultra-structural analyses, in vitro aggregation assays, and secondary structure analyses. The α-synuclein aggregation in the presence of negatively charged SDS suggests that SDS-monomer complexes stimulate the aggregation process. A reduction in the electrostatic repulsion between N- and C-terminal and in the hydrophobic interactions between the NAC (non-amyloid beta component) region and the C-terminal seems to be important to undergo aggregation. Fourier transform infrared spectroscopy (FTIR) measurements show that β-sheet structures comprise the assembly of the fibrils.

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Porous peptide frameworks generated by stacking non-self-complementary β-sheets

Acta Crystallographica Section A Foundations and Advances ◽

10.1107/s2053273314094376 ◽

2014 ◽

Vol 70 (a1) ◽

pp. C562-C562

Author(s):

Dmitriy Soldatov ◽

Abdolreza Yazdani ◽

Julia Crewson ◽

Travis Fillion ◽

Aaron Smith ◽

...

Keyword(s):

Interlayer Space ◽

Specific Property ◽

Close Packing ◽

Bioactive Molecules ◽

Structural Motif ◽

Supramolecular Polymers ◽

Amino Acid Residues ◽

Crystalline Materials ◽

Wide Range ◽

Β Sheet

"One of major approaches in the design of cavity space in the solids utilizes non-self-complementary molecules[1]. The irregular shape of the molecules and/or specific directionality of potential H-bonds prevent close packing of the molecules and yields various architectures hosting a second component, from inclusion compounds and co-crystals to complex non-crystalline patterns in biology. The strategy of non-self-complementary molecules has been extended in our studies to 2D supramolecular polymers based on short peptides[2]. The formation of the peptide layer with a desired overall geometry is controlled by strong, charge-assisted H-bonds (arrows in the Figure) in a β-sheet-like network as well as the segregation of hydrophobic amino acid residues into the interlayer space. The H-bonds add stability to the whole architecture while the hydrophobic groups keep the stacking layers at a distance that generates a cavity space available to a second component (encircled ""G"" in the Figure). A wide range of inclusions and co-crystals have been prepared in our group based on a series of dipeptides and higher peptide oligomers. For example, the incorporation of various organic solvents and bioactive molecules have been demonstrated for leucyl-alanine and similar dipeptides: alcohols, amides, phenols, pyridines, polyols, vitamins, scents and flavors. The crystal structure studies reveal a surprisingly persistent structural motif that can be used for engineering of crystalline materials with a specific property. We believe this type of peptide matrix may be utilized in the solid state organic synthesis [3] as reactive molecules of the second component can be oriented in a predictable way with respect to each other. "

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Time evolution of β-lactoglobulin corona formation on gold nanoparticles and impact on allergy

10.21203/rs.2.23072/v1 ◽

2020 ◽

Author(s):

Xiaoning Zhang ◽

Meifeng Li ◽

Yuanping Lv ◽

Xiaoling Sun ◽

Yao Han ◽

...

Keyword(s):

Gold Nanoparticles ◽

Secondary Structure ◽

Time Evolution ◽

Electrostatic Force ◽

Protein Corona ◽

Raw Milk ◽

Covalent Bonds ◽

Corona Formation ◽

Β Lactoglobulin ◽

Β Sheet

Abstract Gold nanoparticles (AuNPs) are modified immediately by the adsorption of β-lactoglobulin (βlg) when designed as colorimetric probe in raw milk, leading to the formation of a protein corona. This adsorption results mainly from a fast electrostatic force and a slow formation of Au-S covalent bonds, which is a precondition for the use of AuNPs in biodetection. The proteins corona influences the structure and bioactivity of adsorbed protein, such as the allergy. In this study, the mechanism of βlg adsorbed on AuNPs was investigated in terms of stoichiometry, binding affinity (Ka), time evolution of Au-S bond, and general secondary structure changes to address the desensitization of AuNPs. The results show that about 3,600 βlg are adsorbed on a single AuNPs, and the Ka is 2.9 ± 0.7 × 10 6 M -1 . The formation of Au-S bonds takes about 9 h, which is the time needed for complete changes in secondary structure and the IgE combining capacity. The structure of allergenic epitopes assigned to β-sheet was destroyed by the formation of Au-S bond, then induced to the decrease allergy. Furthermore, Fourier transform infrared spectroscopy confirmed a decrease in β-sheet contents after conjugated with AuNPs.

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Impact of Strand Length on the Stability of Parallel-β-Sheet Secondary Structure

Angewandte Chemie ◽

10.1002/ange.201102986 ◽

2011 ◽

Vol 123 (37) ◽

pp. 8894-8897 ◽

Cited By ~ 6

Author(s):

Felix Freire ◽

Aaron M. Almeida ◽

John D. Fisk ◽

Jay D. Steinkruger ◽

Samuel H. Gellman

Keyword(s):

Secondary Structure ◽

The Stability ◽

Β Sheet ◽

Strand Length

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Novel Bovine Serum Albumin Protein Backbone Reassembly Study: Strongly Twisted β-Sheet Structure Promotion upon Interaction with GO-PAMAM

Polymers ◽

10.3390/polym12112603 ◽

2020 ◽

Vol 12 (11) ◽

pp. 2603

Author(s):

Andra Mihaela Onaș ◽

Iuliana Elena Bîru ◽

Sorina Alexandra Gârea ◽

Horia Iovu

Keyword(s):

Secondary Structure ◽

Bovine Serum Albumin ◽

Serum Albumin ◽

Bovine Serum ◽

Infrared Spectrometry ◽

X Ray Diffraction ◽

Protein Backbone ◽

Raman Spectrometry ◽

X Ray ◽

Β Sheet

This study investigates the formation of a graphene oxide-polyamidoamine dendrimer complex (GO-PAMAM) and its association and interaction with bovine serum albumin (BSA). Fourier-transform infrared spectrometry and X-ray photoelectron spectrometry indicated the formation of covalent linkage between the GO surface and PAMAM with 7.22% nitrogen content in the GO-PAMAM sample, and various interactions between BSA and GO-PAMAM, including π-π* interactions at 291.5 eV for the binding energy value. Thermogravimetric analysis highlighted the increasing thermal stability throughout the modification process, from 151 to 192 °C for the 10% weight loss temperature. Raman spectrometry and X-ray diffraction analysis were used in order to examine the complexes’ assembly, showing a prominent (0 0 2) lattice in GO-PAMAM. Dynamic light scattering tests proved the formation of stable graphenic and graphenic-protein aggregates. The secondary structure rearrangement of BSA after interaction with GO-PAMAM was investigated using circular dichroism spectroscopy. We have observed a shift from 10.9% β-sheet composition in native BSA to 64.9% β-sheet composition after the interaction with GO-PAMAM. This interaction promoted the rearrangement of the protein backbone, leading to strongly twisted β-sheet secondary structure architecture.

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