Boiling down the cysteine-stabilized LTP fold - loss of structural and immunological integrity of allergenic Art v 3 and Pru p 3 as a consequence of irreversible lanthionine formation
| Autor: | Sabrina Wildner, Lorenz Stock, Claudia Alessandri, Adriano Mari, Timo Völker, Teresa Stemeseder, Hanno Stutz, Christian G. Huber, Wai Tuck Soh, Hans Brandstetter, Iris Griessner, Christof Regl, Gabriele Gadermaier |
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| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
Circular dichroism Dimer Immunology Size-exclusion chromatography Cross Reactions Sulfides law.invention 03 medical and health sciences chemistry.chemical_compound Epitopes Mice 0302 clinical medicine law Escherichia coli Animals Humans Amino Acid Sequence Cysteine Molecular Biology Lanthionine Plant Proteins Helix bundle Alanine Antigens Plant Immunoglobulin E 030104 developmental biology chemistry Artemisia Immunoglobulin G Biophysics Recombinant DNA Pollen Prunus Carrier Proteins Plant lipid transfer proteins Food Hypersensitivity 030215 immunology |
| Zdroj: | Molecular immunology. 116 |
| ISSN: | 1872-9142 |
| Popis: | Background Non-specific lipid transfer proteins (LTPs) are important allergens in fruits, pollen, vegetables, nuts and latex. Due to their compact structure, LTPs are highly resistant to heat treatment. Here, Art v 3 from mugwort pollen and Pru p 3 from peach were used as model allergens to in-depth investigate structural and immunological properties upon thermal treatment at different buffer conditions. Methods Recombinant Art v 3 and Pru p 3 were purified from E. coli and incubated at 95 °C up to 120 min using sodium phosphate buffer pH 3.4 or 7.3. Physicochemical properties of allergens were analyzed in circular dichroism spectroscopy, Fourier transform infrared spectroscopy, dynamic light scattering, size exclusion chromatography, and mass spectrometry. The crystal structure of Art v 3.0201 was determined to 1.9 A resolution. IgG and IgE binding was investigated in ELISA using murine and LTP allergic patients’ sera. Results Highly pure and homogenous recombinant allergens were obtained from bacterial production. The crystal structure of Art v 3.0201 revealed an antiparallel four helix bundle with a C-terminal extension mediating an asymmetric, transient dimer interface and differently sized cavities. Both allergens showed high thermal stability at acidic conditions. In contrast, extensive heat treatment in neutral buffer induced irreversible structural changes due to lanthionine-based cysteine rearrangement. This fostered loss of the typical α-helical structure, increased molecular size and abrogation of IgG and IgE binding epitopes. Pru p 3 lost its structural integrity at shorter heat stress duration than Art v 3, which did however only partially affect the molecule’s IgE binding epitopes. Conclusion During thermal treatment, susceptibility to structural changes of the LTP-fold is highly dependent on the surrounding environment but also on intrinsic features of individual LTPs. This is a crucial fact to consider when processing LTP-containing food or food products as this will directly influence their allergenic potential. |
| Databáze: | OpenAIRE |
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