Laser Raman Spectroscopic Study Of The β-Sheet Structure Of Fibrinx

Mapping Intimacies ◽

10.1055/s-0038-1652272 ◽

1981 ◽

Author(s):

J Marx ◽

G Hudry-Clergeon ◽

L Bernard

Keyword(s):

Protein Conformation ◽

Protein Concentration ◽

Structural Changes ◽

Fibre Diameter ◽

Enzymatic Conversion ◽

Raman Spectroscopic ◽

Laser Raman ◽

Sheet Structure ◽

Two Parameters ◽

Β Sheet

Raman spectroscopy has proved to be a useful tool in the study of protein conformation in aqueous solution. Structural changes have been observed by this technique during the enzymatic conversion of fibrinogen into fibrin (J. Marx and col. (1979) Biochim. Biophys. Acta., 578, 107-115), particularly by the study of the Amide I and Amide III regions an important increase in the β-sheet form has been shown to occur. This variation is investigated under various conditions of ionic strength (μ) and protein concentration (c), two parameters which are known to change the fibre diameter (low values of μ and c favor an increase in the fibre diameter). The amount of β-sheet structure in fibrinogen is approximately 10 % and is unaffected by μ or c. In fibrin, the amount of β-sheet increases progressively from 20 % in fine clots (low diameter fibres) to more than 30 % in coarse clots (high diameter fibres). This correlation between the percentage of β-sheet structure and fibre diameter in fibrin indicates that numerous intermonomer hydrogen bonds are formed in the equatorial direction of the fibre. These bonds would greatly consolidate the association between monomers which is probably initiated at a few highly specific sites.

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Effect of curcumin on amyloidogenic property of molten globule-like intermediate state of 2,5-diketo-d-gluconate reductase A

Biological Chemistry ◽

10.1515/bc.2009.107 ◽

2009 ◽

Vol 390 (10) ◽

Cited By ~ 11

Author(s):

Nandini Sarkar ◽

Abhay Narain Singh ◽

Vikash Kumar Dubey

Keyword(s):

Protein Concentration ◽

Molten Globule ◽

Molar Ratio ◽

Amyloid Formation ◽

Molten Globule State ◽

Force Microscopy ◽

Atomic Force ◽

Sheet Structure ◽

Amyloid Diseases ◽

Β Sheet

Abstract We identified a molten globule-like intermediate of 2,5-diketo-d-gluconate reductase A (DKGR) at pH 2.5, which has a prominent β-sheet structure. The molten globule state of the protein shows amyloidogenic property >50 μm protein concentration. Interestingly, a 1:1 molar ratio of curcumin prevents amyloid formation as shown by the Thioflavin-T assay and atomic force microscopy. To the best of our knowledge, this is the first report on amyloid formation by an (α/β)8-barrel protein. The results presented here indicate that the molten globule state has an important role in amyloid formation and potential application of curcumin in protein biotechnology as well as therapeutics against amyloid diseases.

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Conformations of calf thymus and rye histones H3 and H4 in aqueous solution by laser Raman spectroscopy

Canadian Journal of Biochemistry ◽

10.1139/o80-087 ◽

1980 ◽

Vol 58 (8) ◽

pp. 633-640 ◽

Cited By ~ 2

Author(s):

M. Pézolet ◽

R. Savoie ◽

J.-G. Guillot ◽

M. Pigeon-Gosselin ◽

D. Pallotta

Keyword(s):

Laser Raman Spectroscopy ◽

Carboxylate Group ◽

Weakly Bound ◽

Tyrosine Residues ◽

Laser Raman ◽

Calf Thymus ◽

Sheet Structure ◽

High Degree ◽

Β Sheet ◽

Positively Charged

The Raman spectra of aqueous solutions of histones H3 and H4 from calf thymus and from rye reflect the high degree of conservation from species to species of the primary and secondary structures of these proteins. The amount of β-sheet structure is estimated at 40 ± 5% in H4 and at 33 ± 5% in H3 from the intensities of the amide I and amide III bands at 1663 and 1241 cm−1, respectively, in the spectra. These values are independent of the salt concentration of the solutions, most likely because of the high histone concentration (~3 mM) required to obtain the spectra, which results in some aggregation of the proteins. The intensity ratio of the tyrosine doublet at 852 and 826 cm−1 indicates that the four tyrosine residues in H4 are relatively exposed to the solvent or weakly bound to positively charged groups of basic amino acids, whereas in H3 at least one tyrosine is buried inside the protein and tightly bound to a carboxylate group. The results also show that the secondary structure of H3 is slightly influenced by the state of oxidation of the two cysteine residues it contains.

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Pathogenic Mutations Induce Partial Structural Changes in the Native β-Sheet Structure of Transthyretin and Accelerate Aggregation

Biochemistry ◽

10.1021/acs.biochem.7b00658 ◽

2017 ◽

Vol 56 (36) ◽

pp. 4808-4818 ◽

Cited By ~ 12

Author(s):

Kwang Hun Lim ◽

Anvesh K. R. Dasari ◽

Renze Ma ◽

Ivan Hung ◽

Zhehong Gan ◽

...

Keyword(s):

Structural Changes ◽

Pathogenic Mutations ◽

Sheet Structure ◽

Β Sheet

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UV Effect on Human Anterior Lens Capsule Macro-Molecular Composition Studied by Synchrotron-Based FTIR Micro-Spectroscopy

International Journal of Molecular Sciences ◽

10.3390/ijms22105249 ◽

2021 ◽

Vol 22 (10) ◽

pp. 5249

Author(s):

Xhevat Lumi ◽

Tanja Dučić ◽

Martin Kreuzer ◽

Marko Hawlina ◽

Sofija Andjelic

Keyword(s):

Protein Conformation ◽

Photon Flux ◽

Lens Epithelial Cells ◽

Stress Markers ◽

Anterior Lens Capsule ◽

Sheet Structure ◽

Synchrotron Light ◽

Uv C ◽

Β Sheet ◽

And Oxidative Stress

Ultraviolet (UV) irradiation is an important risk factor in cataractogenesis. Lens epithelial cells (LECs), which are a highly metabolically active part of the lens, play an important role in UV-induced cataractogenesis. The purpose of this study was to characterize cell compounds such as nucleic acids, proteins, and lipids in human UV C-irradiated anterior lens capsules (LCs) with LECs, as well as to compare them with the control, non-irradiated LCs of patients without cataract, by using synchrotron radiation-based Fourier transform infrared (SR-FTIR) micro-spectroscopy. In order to understand the effect of the UV C on the LC bio-macromolecules in a context of cataractogenesis, we used the SR-FTIR micro-spectroscopy setup installed on the beamline MIRAS at the Spanish synchrotron light source ALBA, where measurements were set to achieve a single-cell resolution with high spectral stability and high photon flux. UV C irradiation of LCs resulted in a significant effect on protein conformation with protein formation of intramolecular parallel β-sheet structure, lower phosphate and carboxyl bands in fatty acids and amino acids, and oxidative stress markers with significant increase of lipid peroxidation and diminishment of the asymmetric CH3 band.

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Structural and Technological Approach to Reveal the Role of the Lipid Phase in the Formation of Soy Emulsion Gels with Chia Oil

Gels ◽

10.3390/gels7020048 ◽

2021 ◽

Vol 7 (2) ◽

pp. 48

Author(s):

Ana M. Herrero ◽

Claudia Ruiz-Capillas

Keyword(s):

Raman Spectroscopy ◽

Structural Properties ◽

Structural Changes ◽

Protein Secondary Structure ◽

Lipid Phase ◽

Α Helix ◽

Β Sheet ◽

Shed Light ◽

Chia Oil

Considerable attention has been paid to emulsion gels (EGs) in recent years due to their interesting applications in food. The aim of this work is to shed light on the role played by chia oil in the technological and structural properties of EGs made from soy protein isolates (SPI) and alginate. Two systems were studied: oil-free SPI gels (SPI/G) and the corresponding SPI EGs (SPI/EG) that contain chia oil. The proximate composition, technological properties (syneresis, pH, color and texture) and structural properties using Raman spectroscopy were determined for SPI/G and SPI/EG. No noticeable (p > 0.05) syneresis was observed in either sample. The pH values were similar (p > 0.05) for SPI/G and SPI/EG, but their texture and color differed significantly depending on the presence of chia oil. SPI/EG featured significantly lower redness and more lightness and yellowness and exhibited greater puncture and gel strengths than SPI/G. Raman spectroscopy revealed significant changes in the protein secondary structure, i.e., higher (p < 0.05) α-helix and lower (p < 0.05) β-sheet, turn and unordered structures, after the incorporation of chia oil to form the corresponding SPI/EG. Apparently, there is a correlation between these structural changes and the textural modifications observed.

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