Effects of pH and salt environment on the association of β-lactoglobulin revealed by intrinsic fluorescence studies

Renard, Denis; Jacques, Laurent; Griffin, Mary C. A.; Griffin, William G.

doi:10.1016/s0141-8130(97)00086-x

Cited by 144 publications

(103 citation statements)

References 40 publications

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“…This quenching of Trp fluorescence probably reveals a slight change in the conformation of PP2-A1-His 6 following interaction with sugar moieties. The absence of a change in maximum fluorescence emission wavelength suggests that Trp residues may not be fully exposed to aqueous solvent, as reported previously in other binding systems (Renard et al, 1998). A hyperbolic fluorescence titration curve was obtained when the results were plotted as a function of sugar-protein molar ratio (Fig.…”

Section: Assessment Of Binding Site Characteristics By Intrinsic Fluosupporting

confidence: 71%

Binding Properties of the N-Acetylglucosamine and High-Mannose N-Glycan PP2-A1 Phloem Lectin in Arabidopsis

et al. 2010

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Phloem Protein2 (PP2) is a component of the phloem protein bodies found in sieve elements. We describe here the lectin properties of the Arabidopsis (Arabidopsis thaliana) PP2-A1. Using a recombinant protein produced in Escherichia coli, we demonstrated binding to N-acetylglucosamine oligomers. Glycan array screening showed that PP2-A1 also bound to highmannose N-glycans and 9-acyl-N-acetylneuraminic sialic acid. Fluorescence spectroscopy-based titration experiments revealed that PP2-A1 had two classes of binding site for N,N#,N$-triacetylchitotriose, a low-affinity site and a high-affinity site, promoting the formation of protein dimers. A search for structural similarities revealed that PP2-A1 aligned with the Cbm4 and Cbm22-2 carbohydrate-binding modules, leading to the prediction of a b-strand structure for its conserved domain. We investigated whether PP2-A1 interacted with phloem sap glycoproteins by first characterizing abundant Arabidopsis phloem sap proteins by liquid chromatography-tandem mass spectrometry. Then we demonstrated that PP2-A1 bound to several phloem sap proteins and that this binding was not completely abolished by glycosidase treatment. As many plant lectins have insecticidal activity, we also assessed the effect of PP2-A1 on weight gain and survival in aphids. Unlike other mannosebinding lectins, when added to an artificial diet, recombinant PP2-A1 had no insecticidal properties against Acyrthosiphon pisum and Myzus persicae. However, at mid-range concentrations, the protein affected weight gain in insect nymphs. These results indicate the presence in PP2-A1 of several carbohydrate-binding sites, with potentially different functions in the trafficking of endogenous proteins or in interactions with phloem-feeding insects.

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Section: Assessment Of Binding Site Characteristics By Intrinsic Fluosupporting

confidence: 71%

Binding Properties of the N-Acetylglucosamine and High-Mannose N-Glycan PP2-A1 Phloem Lectin in Arabidopsis

et al. 2010

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“…[16] No significant changes in the fluorescence at different ionic strengths were also found in our experiment (Fig. 3).…”

Section: Effect Of Ionic Strength On the Interaction Between Eps And Wpsupporting

confidence: 68%

“…At an excitation wavelength higher than 290 nm, it is possible to excite Trp alone. [16] In this research, excitation was performed at 292 nm and the influence of EPS and NaCl concentration on the intrinsic fluorescence intensity of WPs was measured, as shown in Fig. 2.…”

Section: Effect Of Ionic Strength On the Interaction Between Eps And Wpmentioning

confidence: 99%

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Structural and surface properties of whey protein from buffalo milk as influenced by exopolysaccharide

Zhao

et al. 2017

International Journal of Food Properties

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The influence of exopolysaccharide (EPS) on the structure of whey protein (WP) molecules at different pH and ionic strengths was investigated using fluorescence and circular dichroism (CD) spectroscopy. The WPs were separated using 0.2 mol/L glacial acetic acid, which has been proved to maintain to the maximum extent the native structure of WP molecules. The interaction between WP and EPS was significantly influenced by the ionic strength and pH. The presence of NaCl reduced the repulsion and aggregation of WP at pH 7.0. The addition of EPS increased the β-sheet structure of WP and this change tends to disappear at high ionic strength (0.3 mol/L). On the other hand, the repulsive interaction between WP and EPS at pH 7.0 and 6.0 has minimal influence on tryptophan (Trp) quenching and the exposure of hydrophobic residues to the hydrophilic environment. The formation of WP/EPS complexes at pH 5.0 led to the increased exposure of the Trp group to the hydrophilic phase. Both the electrostatic repulsion and attraction increased the secondary structure of WP at all pH values tested in this research. ARTICLE HISTORY

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“…They can be formed from various food proteins like egg white proteins [1][2][3][4][5] , soy proteins 6 , and whey proteins [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] . The fibrils can, for example, be used as structurants and thickeners to give food products a specific texture.…”

Section: Introductionmentioning

confidence: 99%

The Critical Aggregation Concentration of β-Lactoglobulin-Based Fibril Formation

et al. 2009

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The critical aggregation concentration (CAC) for fibril formation of β-lactoglobulin (β-lg) at pH 2 was determined at 343, 353, 358, 363, and 383 K using a Thioflavin T assay and was approximately 0.16 wt%. The accuracy of the CAC was increased by measuring the conversion into fibrils at different stirring speeds. The corresponding binding energy per mol, as determined from the CAC, was 13 RT (∼40 kJ mol −1 ) for the measured temperature range. The fact that the CAC was independent of temperature within the experimental error indicates that the fibril formation of β-lg at pH 2 and the measured temperature range is an entropy-driven process.

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Effects of pH and salt environment on the association of β-lactoglobulin revealed by intrinsic fluorescence studies

Cited by 144 publications

References 40 publications

Binding Properties of the N-Acetylglucosamine and High-Mannose N-Glycan PP2-A1 Phloem Lectin in Arabidopsis

Binding Properties of the N-Acetylglucosamine and High-Mannose N-Glycan PP2-A1 Phloem Lectin in Arabidopsis

Structural and surface properties of whey protein from buffalo milk as influenced by exopolysaccharide

The Critical Aggregation Concentration of β-Lactoglobulin-Based Fibril Formation

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