Surface-enhanced Raman spectrum of Gly-Gly adsorbed on the silver colloidal surface

Yuan, Xiaocong; Gu, Hui; Wu, Jiwei

doi:10.1016/j.molstruc.2010.05.009

Cited by 17 publications

(4 citation statements)

References 29 publications

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“…Most likely a cluster of tyr was present in this specific area of the fibril. Glycine (gly, lilac) and histidine (his, turquoise) can be identified at the end of the line: coexisting bands at 1020 cm −1 and 1320 cm −1 for glycine 34 45 and three bands (1180 cm −1 , 1330 cm −1 , 1495 cm −1 ) for histidine (assignment see Table 1 ). It should be noted that a combination of bands was used for reliable amino acid assignment because a single band is not specific enough in most cases.…”

Section: Resultsmentioning

confidence: 99%

Spatially resolved spectroscopic differentiation of hydrophilic and hydrophobic domains on individual insulin amyloid fibrils

Deckert‐Gaudig

Kurouski

Hedegaard

et al. 2016

Sci Rep

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The formation of insoluble β-sheet-rich protein structures known as amyloid fibrils is associated with numerous neurodegenerative diseases, such as Alzheimer’s and Parkinson’s disease. A detailed understanding of the molecular structure of the fibril surface is of interest as the first contact with the physiological environment in vivo and plays a decisive role in biological activity and associated toxicity. Recent studies reveal that the inherent sensitivity and specificity of tip-enhanced Raman scattering (TERS) renders this technique a compelling method for fibril surface analysis at the single-particle level. Here, the reproducibility of TERS is demonstrated, indicating its relevance for detecting molecular variations. Consequently, individual fibrils are systematically investigated at nanometer spatial resolution. Spectral parameters were obtained by band-fitting, particularly focusing on the identification of the secondary structure via the amide III band and the differentiation of hydrophobic and hydrophilic domains on the surface. In addition multivariate data analysis, specifically the N-FINDR procedure, was employed to generate structure-specific maps. The ability of TERS to localize specific structural domains on fibril surfaces shows promise to the development of new fibril dissection strategies and can be generally applied to any (bio)chemical surface when structural variations at the nanometer level are of interest.

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Section: Resultsmentioning

confidence: 99%

Spatially resolved spectroscopic differentiation of hydrophilic and hydrophobic domains on individual insulin amyloid fibrils

Deckert‐Gaudig

Kurouski

Hedegaard

et al. 2016

Sci Rep

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“…Silver nitrate (AgNO 3 ), sodium borohydride (NaBH 4 ), each of analytical reagent grade, were used to prepare the Ag colloidal solution. The solution of colloidal silver was prepared in deionized water after Xiaojuan et al (2010). First, 8.5 mg AgNO 3 was dissolved in 50 ml deionized water and added dropwise to a 150 ml (1.0 mM) solution of NaBH 4 , while stirring vigorously in an ice bath.…”

Section: Methodsmentioning

confidence: 99%

Synthesis of goethite in solutions of artificial seawater and amino acids: a prebiotic chemistry study

Carneiro¹,

Ivashita

Souza

et al. 2013

International Journal of Astrobiology

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This study investigated the synthesis of goethite under conditions resembling those of the prebiotic Earth. The artificial seawater used contains all the major elements as well as amino acids (α-Ala, β-Ala, Gly, Cys, AIB) that could be found on the prebiotic Earth. The spectroscopic methods (FT-IR, EPR, Raman), scanning electron microscopy (SEM) and X-ray diffraction showed that in any condition Gly and Cys favoured the formation of goethite, artificial seawater plus β-Ala and distilled water plus AIB favoured the formation of hematite and for the other synthesis a mixture of goethite and hematite were obtained. Thus in general no protein amino acids (β-Ala, AIB) favoured the formation of hematite. As shown by surface enhanced Raman spectroscopy (SERS) spectra the interaction between Cys and Fe3+ of goethite is very complex, involving decomposition of Cys producing sulphur, as well as interaction of carboxylic group with Fe3+. SERS spectra also showed that amino/CN and C-CH3 groups of α-Ala are interacting with Fe3+ of goethite. For the other samples the shifting of several bands was observed. However, it was not possible to say which amino acid groups are interacting with Fe3+. The pH at point of zero charge of goethites increased with artificial seawater and decreased with amino acids. SEM images showed when only goethite was synthesized the images of the samples were acicular and when only hematite was synthesized the images of the samples were spherical. SEM images for the synthesis of goethite with Cys were spherical crystal aggregates with radiating acicular crystals. The highest resonance line intensities were obtained for the samples where only hematite was obtained. Electron paramagnetic resonance (EPR) and Mössbauer spectra showed for the synthesis of goethite with artificial seawater an isomorphic substitution of iron by seawater cations. Mössbauer spectra also showed that for the synthesis goethite in distilled water plus Gly only goethite was synthesized and in artificial seawater plus Cys a doublet due to interaction of iron with artificial seawater/Cys was observed. It should be pointed out that EPR spectroscopy did not show the interaction of iron with artificial seawater/Cys.

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“…These spectra could then be compared with reference spectra from the literature for vibrational assignment and purity (see Table S1). − Raman spectra for degradation products, gases, and carbonates were also retrieved from the literature (see Table S2 for a comparison between Raman bands of decomposition products and the glycine molecules). − From the reference solutions we prepared Gly/Gly 2 mixed solutions with a 10 mol % step in Gly 2 concentration (from 0 to 100 mol % Gly 2 ). For Gly/DKP mixtures, we started with a step of 1 mol % from 0 to 10 mol % DKP and used the same 10 mol % steps up to 100 mol % DKP.…”

Section: Methodsmentioning

confidence: 99%

Spontaneous Polymerization of Glycine under Hydrothermal Conditions

Pedreira-Segade

Hao

Montagnac

et al. 2019

ACS Earth Space Chem.

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The abiotic polymerization of nucleotides and amino acids is a prerequisite for the emergence of life. It has been proposed that hydrothermal conditions might favor the polymerization of amino acids. In the present study, we analyzed by in situ Raman spectroscopy in a diamond anvil cell the fate of the simplest and most abundant amino acid, glycine, under hydrothermal conditions at 200 °C and pressures ranging between 50 and 3500 MPa. We also tested the effect of magnetite on the reactivity of glycine. The polymerization of glycine is highly favored under pressure and in the presence of magnetite. Linear dimers are more abundant than the cyclic ones up to a threshold pressure of 500 MPa. Above 800 MPa, amino acids stop reacting and the system is “frozen”. Our findings suggest that pressure and mineral–water interface strongly favor the formation of linear peptides. The optimum conditions for polymerization obtained in the present study suggest that the prebiotic chemical evolution of amino acids was not restricted to hydrothermal vents at oceanic ridges but might also occur much deeper in the first 15–30 km of the crust, widely expanding the prebiotic reactive zone.

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Surface-enhanced Raman spectrum of Gly-Gly adsorbed on the silver colloidal surface

Cited by 17 publications

References 29 publications

Spatially resolved spectroscopic differentiation of hydrophilic and hydrophobic domains on individual insulin amyloid fibrils

Spatially resolved spectroscopic differentiation of hydrophilic and hydrophobic domains on individual insulin amyloid fibrils

Synthesis of goethite in solutions of artificial seawater and amino acids: a prebiotic chemistry study

Spontaneous Polymerization of Glycine under Hydrothermal Conditions

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