Hazelnut (Corylus avellana) vicilin Cor a 11: molecular characterization of a glycoprotein and its allergenic activity

In Europe, hazelnuts (Corylus avellana) are a frequent cause of food allergies. Several important hazelnut allergens have been previously identified and characterized. Specific N-glycans are known to induce strong IgE responses of uncertain clinical relevance, but so far the allergenic potential of glycoproteins from hazelnut has not been investigated. The aim of the study was the molecular characterization of the glycosylated vicilin Cor a 11 from hazelnut and the analysis of its allergenic activity. Although MALDI–TOF (matrix-assisted laser-desorption ionization–time-of-flight) MS showed that one of two potential glycosylation sites of Cor a 11 was glycosylated, CD spectroscopy indicated that recombinant and natural Cor a 11 share similar secondary structures. Thus to analyse the impact of the glycan residues of Cor a 11 on IgE binding, the allergenic activity of natural glycosylated Cor a 11 and recombinant Cor a 11 was compared. In addition, the IgE sensitization pattern to recombinant Cor a 11, Cor a 1, Cor a 2 and Cor a 8 of 65 hazelnut allergic patients was determined in vitro. The prevalence of IgE reactivity to hazelnut vicilin Cor a 11 was below 50%. Basophil histamine-release assays were used to determine the allergenic activity of both natural and recombinant Cor a 11 in comparison with Cor a 1, a birch (Betula verrucosa) pollen-related major hazelnut allergen. Both forms of Cor a 11 induced mediator release from basophils to a similar extent, indicating that the hazelnut allergic patients had cross-linking IgE antibodies binding to the protein backbone and not to carbohydrate structures. In comparison to Cor a 1, a 10000-fold higher concentration of Cor a 11 was required to induce similar basophil mediator release. In conclusion, the hazelnut vicilin Cor a 11 is a minor allergen both in regard to prevalence and allergenic potency, whereas its glycan does not contribute to its allergenic activity.

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Cellular and molecular characterization of the impact of laboratory setup on bovine in vitro embryo production

Theriogenology ◽

10.1016/j.theriogenology.2011.12.021 ◽

2012 ◽

Vol 77 (9) ◽

pp. 1767-1778.e1 ◽

Cited By ~ 8

Author(s):

Dany Plourde ◽

Christian Vigneault ◽

Isabelle Laflamme ◽

Patrick Blondin ◽

Claude Robert

Keyword(s):

Molecular Characterization ◽

Embryo Production ◽

Laboratory Setup ◽

In Vitro Embryo Production ◽

The Impact

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Isolation and structural elucidation of dimeric epigallocatechin-3-gallate autoxidation products and their antioxidant capacity

European Food Research and Technology ◽

10.1007/s00217-021-03846-3 ◽

2021 ◽

Author(s):

Julian Alfke ◽

Uta Kampermann ◽

Svetlana Kalinina ◽

Melanie Esselen

Keyword(s):

Antioxidant Capacity ◽

Antioxidant Properties ◽

Cd Spectroscopy ◽

Trolox Equivalent Antioxidant Capacity ◽

Published Data ◽

Dietary Polyphenols ◽

Cellular Effects ◽

The Impact

AbstractDietary polyphenols like epigallocatechin-3-gallate (EGCG)—which represents the most abundant flavan-3-ol in green tea—are subject of several studies regarding their bioactivity and health-related properties. On many occasions, cell culture or in vitro experiments form the basis of published data. Although the stability of these compounds is observed to be low, many reported effects are directly related to the parent compounds whereas the impact of EGCG degradation and autoxidation products is not yet understood and merely studied. EGCG autoxidation products like its dimers theasinensin A and D, “P2” and oolongtheanin are yet to be characterized in the same extent as their parental polyphenol. However, to investigate the bioactivity of autoxidation products—which would minimize the discrepancy between in vitro and in vivo data—isolation and structure elucidation techniques are urgently needed. In this study, a new protocol to acquire the dimers theasinensin A and D as well as oolongtheanin is depicted, including a variety of spectroscopic and quadrupole time-of-flight high-resolution mass spectrometric (qTOF-HRMS) data to characterize and assign these isolates. Through nuclear magnetic resonance (NMR) spectroscopy, polarimetry, and especially circular dichroism (CD) spectroscopy after enzymatic hydrolysis the complementary atropisomeric stereochemistry of the isolated theasinensins is illuminated and elucidated. Lastly, a direct comparison between the isolated EGCG autoxidation products and the monomer itself is carried out regarding their antioxidant properties featuring Trolox equivalent antioxidant capacity (TEAC) values. These findings help to characterize these products regarding their cellular effects and—which is of special interest in the flavonoid group—their redox properties.

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SureSelect targeted enrichment, a new cost effective method for the whole genome sequencing of Candidatus Liberibacter asiaticus

Scientific Reports ◽

10.1038/s41598-019-55144-4 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 2

Author(s):

Weili Cai ◽

Schyler Nunziata ◽

John Rascoe ◽

Michael J. Stulberg

Keyword(s):

Whole Genome Sequencing ◽

Molecular Characterization ◽

Genome Sequencing ◽

Whole Genome Sequence ◽

Whole Genome ◽

Genome Coverage ◽

Metagenomic Sample ◽

Liberibacter Asiaticus

AbstractHuanglongbing (HLB) is a worldwide deadly citrus disease caused by the phloem-limited bacteria ‘Candidatus Liberibacter asiaticus’ (CLas) vectored by Asian citrus psyllids. In order to effectively manage this disease, it is crucial to understand the relationship among the bacterial isolates from different geographical locations. Whole genome sequencing approaches will provide more precise molecular characterization of the diversity among populations. Due to the lack of in vitro culture, obtaining the whole genome sequence of CLas is still a challenge, especially for medium to low titer samples. Hundreds of millions of sequencing reads are needed to get good coverage of CLas from an HLB positive citrus sample. In order to overcome this limitation, we present here a new method, Agilent SureSelect XT HS target enrichment, which can specifically enrich CLas from a metagenomic sample while greatly reducing cost and increasing whole genome coverage of the pathogen. In this study, the CLas genome was successfully sequenced with 99.3% genome coverage and over 72X sequencing coverage from low titer tissue samples (equivalent to 28.52 Cq using Li 16 S qPCR). More importantly, this method also effectively captures regions of diversity in the CLas genome, which provides precise molecular characterization of different strains.

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The Proteome of Brain Capillary Endothelial Cells: Toward a Molecular Characterization of an In Vitro Blood–Brain Barrier Model

Expression Profiling in Neuroscience - Neuromethods ◽

10.1007/978-1-61779-448-3_10 ◽

2011 ◽

pp. 161-179 ◽

Cited By ~ 2

Author(s):

Sophie Duban-Deweer ◽

Christophe Flahaut ◽

Yannis Karamanos

Keyword(s):

Endothelial Cells ◽

Molecular Characterization ◽

Blood Brain Barrier ◽

Brain Barrier ◽

Brain Capillary ◽

Blood Brain Barrier Model ◽

Capillary Endothelial Cells ◽

Barrier Model

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Molecular Characterization of HOXA2 and HOXA3 Binding Properties

Journal of Developmental Biology ◽

10.3390/jdb9040055 ◽

2021 ◽

Vol 9 (4) ◽

pp. 55

Author(s):

Joshua Mallen ◽

Manisha Kalsan ◽

Peyman Zarrineh ◽

Laure Bridoux ◽

Shandar Ahmad ◽

...

Keyword(s):

Transcription Factors ◽

Molecular Characterization ◽

Sequence Motif ◽

Body Parts ◽

Binding Affinities ◽

Binding Properties ◽

Functional Consequences

The highly conserved HOX homeodomain (HD) transcription factors (TFs) establish the identity of different body parts along the antero–posterior axis of bilaterian animals. Segment diversification and the morphogenesis of different structures is achieved by generating precise patterns of HOX expression along the antero–posterior axis and by the ability of different HOX TFs to instruct unique and specific transcriptional programs. However, HOX binding properties in vitro, characterised by the recognition of similar AT-rich binding sequences, do not account for the ability of different HOX to instruct segment-specific transcriptional programs. To address this problem, we previously compared HOXA2 and HOXA3 binding in vivo. Here, we explore if sequence motif enrichments observed in vivo are explained by binding affinities in vitro. Unexpectedly, we found that the highest enriched motif in HOXA2 peaks was not recognised by HOXA2 in vitro, highlighting the importance of investigating HOX binding in its physiological context. We also report the ability of HOXA2 and HOXA3 to heterodimerise, which may have functional consequences for the HOX patterning function in vivo.

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