Increase In Amide Research Articles

Early on–site detection of strawberry anthracnose using portable Raman spectroscopy

We developed a method for the early on–site detection of strawberry anthracnose using a portable Raman system with multivariate statistical analysis algorithms. By using molecular markers based on Raman spectra, the proposed method can detect anthracnose in strawberry stems 3 days after exposure to Colletotrichum gloeosporioides. A fiber–optic probe was applied for the portable Raman system, and the acquisition time was 10 s. We found that the molecular markers were closely related to the following subjects: i) an increase in amide III and fatty acids of C. gloeosporioides invading strawberry stems (Raman bands at 1180–1310 cm−1) and ii) a decrease in metabolites in strawberry plants, such as phenolic compounds and terpenoids (Raman bands at 760, 800, and 1523 cm−1). We also found that the increased fluorescence background caused by various chromophores within the invading C. gloeosporioides could serve as a marker. A two–dimensional cluster plot obtained by principal component analysis (PCA) showed that the three groups (control, fungal infection, and pathogen) were distinguishable. The linear discriminant analysis (LDA)–based prediction algorithm could identify C. gloeosporioides infection with a posterior probability of over 40%, even when no symptoms were visible on the inoculated strawberry plants.

Gymnema inodorum (Lour.) Decne. Extract Alleviates Oxidative Stress and Inflammatory Mediators Produced by RAW264.7 Macrophages.

Gymnema inodorum (Lour.) Decne. (G. inodorum) is widely used in Northern Thai cuisine as local vegetables and commercial herb tea products. In the present study, G. inodorum extract (GIE) was evaluated for its antioxidant and anti-inflammatory effects in LPS plus IFN-γ-induced RAW264.7 cells. Major compounds in GIE were evaluated using GC-MS and found 16 volatile compounds presenting in the extract. GIE exhibited antioxidant activity by scavenging the intracellular reactive oxygen species (ROS) production and increasing superoxide dismutase 2 (SOD2) mRNA expression in LPS plus IFN-γ-induced RAW264.7 cells. GIE showed anti-inflammatory activity through suppressing nitric oxide (NO), proinflammatory cytokine production interleukin 6 (IL-6) and also downregulation of the expression of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and IL-6 mRNA levels in LPS plus IFN-γ-induced RAW264.7 cells. Mechanism studies showed that GIE suppressed the NF-κB p65 nuclear translocation and slightly decreased the phosphorylation of NF-κB p65 (p-NF-κB p65) protein. Our studies applied the synchrotron radiation-based FTIR microspectroscopy (SR-FTIR), supported by multivariate analysis, to identify the FTIR spectral changes based on macromolecule alterations occurring in RAW264.7 cells. SR-FTIR results demonstrated that the presence of LPS plus IFN-γ in RAW264.7 cells associated with the increase of amide I/amide II ratio (contributing to the alteration of secondary protein structure) and lipid content, whereas glycogen and other carbohydrate content were decreased. These findings lead us to believe that GIE may prevent oxidative damage by scavenging intracellular ROS production and activating the antioxidant gene, SOD2, expression. Therefore, it is possible that the antioxidant properties of GIE could modulate the inflammation process by regulating the ROS levels, which lead to the suppression of proinflammatory cytokines and genes. Therefore, GIE could be developed into a novel antioxidant and anti-inflammatory agent to treat and prevent diseases related to oxidative stress and inflammation.

The influence of irrigation solutions in the inorganic and organic radicular dentine composition.

The aim of this study was to analyse changes in radicular dentine composition after different irrigation regimes using attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR). Dentine slices from human single-root teeth were immersed in: (i) 5.25% sodium hypochlorite (NaOCl) for 1, 5 and 20min; (ii) 17% EDTA for 1min; and (iii) 5.25% NaOCl for 20min, and 17% EDTA and 5.25% NaOCl, both for 1min. Carbonate/mineral, Amide I/mineral and Amide III/CH2 ratios were determined using ATR-FTIR before and after immersion in the irrigation solutions tested. Results showed that 5.25% NaOCl significantly decreased carbonate/mineral, Amide I/mineral and Amide III/CH2 ratios (P<0.05). Application of 17% EDTA produced no change in carbonate/mineral ratio (P=0.120), while an increase in Amide I/mineral in apical third (P=0.002) and Amide III/CH2 (P<0.001) was observed. The combination of NaOCl, EDTA and NaOCl increased carbonate/mineral ratio in coronal third (P=0.037), and Amide I/mineral (P=0.003) and Amide III/CH2 (P=0.001) ratios. In conclusion, irrigation solutions tested significantly affected radicular dentine composition.

Esterases with an Introduced Amidase‐Like Hydrogen Bond in the Transition State Have Increased Amidase Specificity

By using rational design an amidase-like hydrogen bond (indicated by the arrow) was introduced into the transition states of Candida antarctica lipase B and Humicola insolens cutinase. The best mutant displayed a 50-fold increase in amide over ester bond hydrolysis compared to the wild type.

Monitoring of spectroscopic changes of a single trapped fission yeast cell by using a Raman tweezers set-up

We demonstrate an improvement of the sensitivity of a Raman tweezers set-up, which combines optical tweezers with Raman spectroscopy. The system was tested by taking the Raman spectrum of a 4.6 μm diameter polystyrene sphere trapped in an aqueous solution. The improvement of sensitivity of the set-up was achieved by adjusting the trap depth for maximum signal to noise ratio (SNR). The maximum SNR was obtained by investigating the Raman peak of a trapped polystyrene sphere at 1001 cm −1 according to trap depth. With this system, a single trapped living Schizosaccharomyces Pombe yeast cell was sensitively monitored by taking the kinetic Raman spectra for more than 2 h. The relative intensity decrease in amide I and amide III bands, frequency increase in amide I band together with alterations in tyrosine marker band around 850 cm −1 was observed, which indicates alterations in the hydration state of protein by time progressing.

Biomolecular investigation of human substantia nigra in Parkinson’s disease by synchrotron radiation Fourier transform infrared microspectroscopy

Synchrotron radiation based-Fourier transform infrared microspectroscopy was used for preliminary investigation of the chemical composition and morphologies of the human substantia nigra of brain between normal and Parkinson’s diseased tissues. The studies were carried out for thin tissue sections, focusing more particularly on nerve cell bodies, that are affected in Parkinson’s disease (PD). The major spectral differences between normal (control) and PD tissues were identified at the following vibrational frequencies: 2930, 2850, 1655, 1380, 1236, 1173 and 1086 cm −1. The infrared imaging of these biochemical markers show that for control cases the protein and nucleic acids functional groups (bands at: ∼3300, ∼3100, ∼1655, ∼1545, ∼1240, ∼1080 cm −1) are located mainly in the cell body. The spatial distribution of the band at 1740 cm −1 (ester carbonyl stretching band) is quite dissimilar to the others, while it exhibits a minimal concentration in the cell body area. Contrarily, in PD samples, no clear evidence of variation of any of the vibrational fingerprint between cell body and the surrounding was noticed. Moreover, decrease of protein to lipid ratio as well as increase of amide I/amide II ratio were observed for PD case. The preliminary results strengthen the hypothesis that PD is a multietiological disorder. Moreover, the reported results clearly indicate that, in addition to a distinct visual observation, the diseased nerve cells exhibits change of their biochemical composition. It suggests that disturbances of normal functioning of SN neurons appear before their morphological atrophy.

Direct Infrared Spectroscopic Evidence of pH- and Ionic Strength-Induced Changes in Distance of Attached Pseudomonas aeruginosa from ZnSe Surfaces

Control of bacterial adhesion is important in many industrial and medical applications. Ionic strength and pH are known to affect the process of attachment; however their influence on bacteria/surface distances has been inferred but not quantitatively established. The distances between attached bacteria and surfaces have only recently been measured. In this paper ATR-IR spectroscopy has been used to study the influence of pH and ionic strength on the distance of freshly attached Pseudomonas aeruginosa from ZnSe surfaces. Reversible changes in the absorbance of P. aeruginosa were observed for changes of pH between 4 and 10 at a constant ionic strength of 0.003 mol L-1 and for changes of ionic strength between 0 and 0.15 mol L-1 at a constant pH of 6.3. An increase in ionic strength from 0 to 0.003 mol L-1 led to an increase in amide II absorbance of 30%, which corresponds to an average movement of 120 nm toward the surface. A movement of this magnitude is likely to be due to changes in the length of bacter...

Effect of acidic conditioners on dentin morphology, molecular composition and collagen conformation in situ

Objective: The aim of the study was to evaluate the effect of some acidic conditioners on dentin morphology, molecular composition and collagen conformation in situ. Methods: Smear layer-covered dentin specimens prepared from third molars immediately after extraction were imaged by tapping mode AFM and analyzed by MIR-FTIR spectroscopy. The same specimens were subjected to conditioning treatments with CA Agent (Kuraray), Scotchbond Etchant (3M Dental Products) and Scotchbond MP Etchant (3M Dental Products) gels and then imaged and analyzed again. The extent of dentin decalcification at the uppermost 2 μm region was calculated from the percentage reduction in the -PO 4/amide I peak area ratio of conditioned specimens relative to their individual smear layer-covered references. These results were compared by ANOVA and Scheffe´statistical analyses. The conformational changes of dentin type I collagen at the region were studied qualitatively by deconvoluting the amide I bands of MIR-FTIR spectra and assigning the band components to carbonyl hydrogen bonding states related to the α-helix structure. Results: All the conditioners removed the smear layer, funneled the tubules, increased the intertubular roughness and contaminated the dentin surfaces with residues from irreversibly adsorbed thickening agents. Conditioned dentin surfaces showed a reduction in orthophosphates and carbonates and an increase in amide I, II and III groups. CA Agent manifested a significantly lower extent of dentin decalcification than Scotchbond etchants (p < 0.05). Collagen conformational changes involved a decrease in intermolecular hydrogen bonded amide I carbonyls associated with the α-helix structure and enhancement of imide carbonyls hydrogen bonded to water, which suggest collagen denaturation. Significance: Apart from dentin decalcification, the acidic conditioners induced considerable changes on dentin collagen conformation mostly associated with denaturation processes. In addition, irreversibly adsorbed residual thickeners substantially modified the morphology and composition of dentin surfaces. These findings show the complex interaction pathways between conditioners and dentin surfaces and the great potential of modern in situ imaging and analysis techniques in probing these interactions.

Glutamyl and aspartyl moieties of cerebral proteins: enrichment in membrane-containing microsomal subfractions.

Abstract— The total mixed proteins (excluding proteolipids) were isolated from various tissues of the cat and from subcellular fractions of cat cerebral cortex and were compared for contents of total glutamyl and total aspartyl residues and total amide N. The proteins from renal cortex, testis and diaphragm were more acidic (proportionally more glutamyl and aspartyl residues with no increase of amide) than those from cerebral cortex, subcortical white matter and liver. Also the proteins isolated from cerebral cortical microsomes were more acidic than those from highly pure nuclear, mitochondrial and soluble subcellular fractions of cerebral cortex. Hepatic microsomal proteins gave very similar analyses.Subfractionation of the microsomal preparations from cerebral cortex and liver into deoxycholate‐insoluble (ribosomal) and deoxycholate‐soluble (‘membrane’) fractions localized the acidic proteins to the latter, ‘membrane’ subtraction. The ribosomal proteins isolated from cerebral cortex (and liver) had an amino acid composition very similar to that reported previously for ribosomal proteins in a number of tissues from various species. Upon column chromatography on DEAE‐celluIose, the deoxycholate‐soluble (‘membrane’) subtraction of hepatic microsomes yielded a peak (eluted with 0‐2 M‐phosphate, pH 5‐6, plus 0‐5 M‐NaCl) that contained an exceptionally high proportion (30 per cent) of glutamyl and aspartyl residues. We suggest that such acidic proteins may be characteristic of membranes and may subserve important metabolic functions therein.