Influence of glycation and pepsin hydrolysis on immunoreactivity of albumin/globulin fraction of herbicide resistant wheat line

Nagy, András; Marciniak-Darmochwał, Katarzyna; Krawczuk, Stanisław; Mierzejewska, Dagmara; Kostyra, H.; Gelencsér, É.

doi:10.17221/48/2008-cjfs

Cited by 11 publications

(5 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, as the glyoxal concentration was increased to 20%, Trp fluorescence intensity significantly decreased with a red shift of 5 nm relative to native (curve 2). This is due to the transfer of Trp residues to a more polar environment [27]. At 70% glyoxal, there was further reduction in fluorescence intensity compared to 20% glyoxal (curve 3).…”

Section: Resultsmentioning

confidence: 96%

Molten Globule of Hemoglobin Proceeds into Aggregates and Advanced Glycated End Products

et al. 2013

View full text Add to dashboard Cite

Conformational alterations of bovine hemoglobin (Hb) upon sequential addition of glyoxal over a range of 0–90% v/v were investigated. At 20% v/v glyoxal, molten globule (MG) state of Hb was observed by altered tryptophan fluorescence, high ANS binding, existence of intact heme, native-like secondary structure as depicted by far-UV circular dichroism (CD) and ATR-FTIR spectra as well as loss in tertiary structure as confirmed by near-UV CD spectra. In addition, size exclusion chromatography analysis depicted that MG state at 20% v/v glyoxal corresponded to expanded pre-dissociated dimers. Aggregates of Hb were detected at 70% v/v glyoxal. These aggregates of Hb had altered tryptophan environment, low ANS binding, exposed heme, increased β-sheet secondary structure, loss in tertiary structure, enhanced thioflavin T (ThT) fluorescence and red shifted Congo Red (CR) absorbance. On incubating Hb with 30% v/v glyoxal for 0–20 days, advanced glycation end products (AGEs) were detected on day 20. These AGEs were characterised by enhanced tryptophan fluorescence at 450 nm, exposure of heme, increase in intermolecular β-sheets, enhanced ThT fluorescence and red shift in CR absorbance. Comet assay revealed aggregates and AGEs to be genotoxic in nature. Scanning electron microscopy confirmed the amorphous structure of aggregates and branched fibrils of AGEs. The transformation of α-helix to β-sheet usually alters the normal protein to amyloidogenic resulting in a variety of protein conformational disorders such as diabetes, prion and Huntington's.

show abstract

Section: Resultsmentioning

confidence: 96%

Molten Globule of Hemoglobin Proceeds into Aggregates and Advanced Glycated End Products

et al. 2013

View full text Add to dashboard Cite

show abstract

“…After SGF digestion, the free amino group contents of N-β-Lg-G, H-β-Lg-G, and Ara-β-Lg-G were 0.140, 0.143, and 0.089 mg/mL, respectively, and Ara-β-Lg-G had the lowest content ( p < 0.05). Furthermore, the DH values of N-β-Lg-G, H-β-Lg-G, and Ara-β-Lg-G were 23.95%, 28.07%, and 21.15% ( p < 0.05), respectively, indicating that glycation might lead to a steric hindrance to prevent pepsin from hydrolyzing peptide bonds near modified lysine or arginine . Zhao et al also proved that β-Lg glycated with α-dicarbonyl compounds reduced the digestibility of the in vitro gastric stage.…”

Section: Resultsmentioning

confidence: 98%

Mechanism of the Reduced IgG/IgE Binding Abilities of Glycated β-Lactoglobulin and Its Digests through High-Resolution Mass Spectrometry

Wang

et al. 2021

J. Agric. Food Chem.

View full text Add to dashboard Cite

Glycation between proteins and reducing sugars is the common chemical modification in food protein, and many studies have focused on the allergenicity of the glycated protein. However, a systemic study on the allergenicity change of its digests is lacking. In this work, we explored the change rule of the digestibility and allergenicity of glycated β-Lg during in vitro gastrointestinal digestion and interpreted the mechanism using high-resolution mass spectrometry. Glycation with arabinose increased the resistance of β-Lg to digestive enzyme, with a low hydrolysis value. Indirect competitive ELISA showed that the IgG/IgE binding rates of β-Lg were reduced after glycation and further reduced after digestion, in comparison with the digests of unglycated β-Lg. There are two reasons for this phenomenon. On the one hand, 11 glycated sites were determined in the lowest allergenicity arabinose-β-Lg conjugation (Ara-β-Lg), which was distributed in the IgG and IgE linear allergic epitopes of β-Lg. On the other hand, glycation masking linear allergenic epitopes had a more significant effect on reducing allergenicity in comparison to digestive enzyme hydrolysis. These results indicated that the allergenicity of Ara-β-Lg in the human body might be lower than that of unglycated β-Lg.

show abstract

“…Upon incubation, the decrease in emission was accompanied by a progressive bathochromic shift (~15 nm) in the wavelength of maximum emission (λ max ). This shift usually corresponds to an exposure of intrinsic tryptophan residues of glycated protein to a more polar medium in the presence of carbohydrates [ 54 ]. Fluorescence emission of Trp7 is significantly quenched by Lys79 (EF2 helix), therefore a red shift in emission could be also due to the movement of this Lys away from Trp7 when the α-helix unfolds [ 55 ] as a result of glycation.…”

Section: Resultsmentioning

confidence: 99%

Rapid Myoglobin Aggregation through Glucosamine-Induced α-Dicarbonyl Formation

2015

View full text Add to dashboard Cite

The extent of glycation and conformational changes of horse myoglobin (Mb) upon glycation with N-acetyl-glucosamine (GlcNAc), glucose (Glc) and glucosamine (GlcN) were investigated. Among tested sugars, the rate of glycation with GlcN was the most rapid as shown by MALDI and ESI mass spectrometries. Protein oxidation, as evaluated by the amount of carbonyl groups present on Mb, was found to increase exponentially in Mb-Glc conjugates over time, whereas in Mb-GlcN mixtures the carbonyl groups decreased significantly after maximum at 3 days of the reaction. The reaction between GlcN and Mb resulted in a significantly higher amount of α-dicarbonyl compounds, mostly glucosone and 3-deoxyglucosone, ranging from and 27 to 332 mg/L and from 14 to 304 mg/L, respectively. Already at 0.5 days, tertiary structural changes of Mb-GlcN conjugate were observed by altered tryptophan fluorescence. A reduction of metmyoglobin to deoxy-and oxymyoglobin forms was observed on the first day of reaction, coinciding with the greatest amount of glucosone produced. In contrast to native α-helical myoglobin, 41% of the glycated protein sequence was transformed into a β-sheet conformation, as determined by circular dichroism spectropolarimetry. Transmission electron microscopy demonstrated that Mb glycation with GlcN causes the formation of amorphous or fibrous aggregates, started already at 3 reaction days. These aggregates bind to an amyloid-specific dye thioflavin T. With the aid of α-dicarbonyl compounds and advanced products of reaction, this study suggests that the Mb glycation with GlcN induces the unfolding of an initially globular protein structure into amyloid fibrils comprised of a β-sheet structure.

show abstract

Influence of glycation and pepsin hydrolysis on immunoreactivity of albumin/globulin fraction of herbicide resistant wheat line

Cited by 11 publications

References 24 publications

Molten Globule of Hemoglobin Proceeds into Aggregates and Advanced Glycated End Products

Molten Globule of Hemoglobin Proceeds into Aggregates and Advanced Glycated End Products

Mechanism of the Reduced IgG/IgE Binding Abilities of Glycated β-Lactoglobulin and Its Digests through High-Resolution Mass Spectrometry

Rapid Myoglobin Aggregation through Glucosamine-Induced α-Dicarbonyl Formation

Contact Info

Product

Resources

About