Phaseolin: A 47.5kDa protein of red kidney bean (Phaseolus vulgaris L.) plays a pivotal role in hypersensitivity induction

Molecular and immunological characterization of cysteine protease from Phaseolus vulgaris and evolutionary cross-reactivity

A commonly consumed legume in India, the kidney bean (Phaseolus vulgaris) is associated with allergy. We report molecular and immunological characterization of cysteine protease allergen and its cross-reactivity. In silico allergenicity assessment and phylogenetic analysis of kidney bean cysteine protease showed significant sequence homology (upto 67%) with allergens from kiwi, papaya, soybean, ragweed pollen and mites. Physicochemical properties and motif-analysis depicted cysteine protease as probable allergen. Multiple sequence alignment and phylogenetic analysis indicated structural conservation between kidney bean and homologous cysteine protease sequences. The gene was cloned, expressed and affinity purified. Cysteine protease was resolved at 42 kDa and exhibited high IgE binding (up to 89%) with hypersensitive sera. Cysteine protease showed functional property on cross-linking IgE receptors and upregulated expression of CD203c on activated basophils. In inhibition studies, 8.4 ng of cysteine protease was required for 50% self-inhibition, whereas significant inhibition was also observed with kidney bean (52 ng), black gram (155 ng), chick pea (437 ng), mesquite pollen (36 ng), house dust mite (64.85 ng), Alternaria alternata (78.8 ng) and Curvularia lunata (73.6 ng) extracts. ConSurf analysis indicated conserved active site and catalytic residues in mature domain among proteases from legumes, fruits, pollens, mites and fungus. In summary, P. vulgaris cysteine protease was molecularly characterized having functional activity. This study demonstrated, cross-reactivity between food and aeroallergens based on evolutionary conservancy that showed its clinical importance as cross-reactive allergen. PRACTICAL APPLICATIONS: Adaptation of sustainable lifestyle has led to a surge in consumption of plant-based foods especially legumes. Their high nutritional content lowers the risk of developing cardiovascular diseases, diabetes, obesity, and stroke. Kidney beans, a commonly consumed legume in Indian subcontinent, have a potential to be used as nutraceutical and functional food. Despite its alimentary nature, it elicits allergic reactions. Being a major sensitizer, trivial information regarding its allergic components has led to an urgent need for exploring its allergen repertoire. Our study reported biochemical and immunological characterization of its major cysteine protease allergen. Cysteine proteases are major cross-reactive allergens from insects, fruits and fungal sources. Identification and molecular characterization of such immunodominant allergens by RDT offers the prospect of using recombinant proteins for accurate diagnosis and therapeutic purposes. This study suggests that a potential major cross-reactive allergen may aid in developing allergy management interventions for a wide range of allergenic sources.

Revealing the anti-melanoma mechanism of n-BuOH fraction from the red kidney bean coat extract based on network pharmacology and transcriptomic approach

Red kidney bean coat (RKBC) extract contains bioactive compounds that are known to exhibit anti-melanoma activity in vitro. However, knowledge on antitumor component and mechanism of RKBC extract has not been fully clarified. Here, RKBC extract was portioned with different solvent sequentially, and based on the cell viability assay, cell migration assay, AO/EB and Hoechst 33342 staining assay, and Annexin V-FITC/PI double staining, n-BuOH (BU) fraction was identified as the most potent antitumor fraction. It exhibited potential anti-melanoma activity via the induction of apoptosis and vacuolization in B16-F10 cells. Transcriptomic and bioprocess-target network analysis revealed that BU fraction triggered apoptosis and vacuolization through regulating PI3K-AKT-FOXO, MDM2-p53 pathway and increasing the expression of Bcl-xl. In addition, quercetin might be served as one of the key anti-melanoma compounds in BU fraction through the similar mechanism. Although the anti-melanoma activity and mechanism of BU fraction have not been elucidated completely, this study effectively expands our understanding for the anti-melanoma activity of RKBC extract and provided the basis for the further functional food research and development using red kidney bean, as well as a new possibility for treating melanoma.

Kidney-bean (Phaseolus Vulgaris) Dependent, Exercise-induced Anaphylaxis in Patients Comorbid with Mugwort (Artemisia Vulgaris) Pollinosis

Background: The cross-reactive allergen between mugwort (Artemisia vulgaris) and kidney bean (Phaseolus vulgaris) has not yet been identified.Methods: A total of 24 patients were included in this study. The sera of patients were analyzed for the concentrations of specific IgE antibodies. The allergenicity and cross-reactivity were investigated by Western blotting and immunoblot inhibitory experiments.Results: The immunoblotting indicated the binding of patients' IgE to crude mugwort extract at ~26 kDa protein (15 cases), ~60 kDa (15 cases), and 10-15 kDa proteins (12 cases). The results of the immunoblot-inhibition assay showed that kidney bean seed extract inhibited specific IgE binding to mugwort at 10-15 kDa, ~26 kDa, and ~60 kDa in 4 (16.7%), 1 (4.2%) and 2 (8.3%) cases, respectively. On the other hand, mugwort extract was demonstrated to inhibit specific IgE binding to kidney bean seed at 10-15 kDa, 15-20 kDa, ~30 kDa, and 60 kDa in 1 (4.2%), 3 (12.5%), 4 (16.7%), and 3 (12.5%) cases, respectively.Conclusion: The 26-30 kDa, 10-15 kDa, and 60 kDa proteins are potential causative agents of the cross-reactivity between mugwort and kidney beans. The findings of this study improved the current understanding on the allergenicity of kidney beans and would provide insights into the refinement of treatment strategy for anaphylaxis.

Identification and characterization of major IgE binding of purified allergenic protein (11 kDa) from Buchanania lanzan

Tree nut along with peanut are among the most potent food allergens, responsible for frequently inducing the IgE-mediated hypersensitivity reaction. Our aim was identification, purification of Buchanania lanzan (Bl-11 kDa) protein along with characterization and assessment of allergenic potential of clinically relevant allergen. Further study was executed in clinical samples of sensitive patients, BALB/c mice, and in-vitro. A major IgE binding 11-kDa protein from Buchanania lanzan was purified by anion exchange chromatography, reverse phase high pressure liquid chromatography (RP-HPLC) and characterized using peptide mass fingerprinting (PMF). Buchanania lanzan (Bl-11 kDa) protein shows the pepsin resistance and depicts IgE interacting capacity to Buchanania lanzan allergic patient's sera as well as sensitized mice sera. It also showed increase in the allergic mediator's like IgE, IgG1, histamine levels in sensitized mice sera. Further study was carried out in-vitro (RBL-2H3 cells) and increased release mast cell degranulation mediators such as β-hexosaminidase, histamine, CysL and PGD2 in the culture supernatant was found. The activation of Th2 cytokines/transcription factors and expression of molecular markers in the downstream of mast cell signaling were up-regulated while the Th1 transcriptional factor (T-bet) was decreased in Bl-11 kDa protein treated mice. Conclusively, our study demonstrates Buchanania lanzan purified protein to be potential allergen that may generate an allergic reaction in sensitized individuals, and one of the most important IgE binding protein responsible for its allergenicity.

Uncovering the anti-proliferation mechanism and bioactive compounds in red kidney bean coat against B16-F10 melanoma cells by metabolomics and network pharmacology analysis

In this study, coat (RKBC) and kernel (RKBK) extracts of red kidney bean were prepared, and their chemical compositions and potential anti-cancer activity against B16-F10 cells were evaluated.

Allergy to Peanut, Soybean, and Other Legumes: Recent Advances in Allergen Characterization, Stability to Processing and IgE Cross-Reactivity

Peanut and soybean are members of the Leguminosae family. They are two of the eight foods that account for the most significant food allergies in the United States and Europe. Allergic reactions to other legume species can be of importance in other regions of the world. The major allergens from peanut and soybean have been extensively analyzed and members of new protein families identified as potential marker allergens for symptom severity. Important recent advances concerning their molecular properties or clinical relevance have been made. Therefore, there is increasing interest in the characterization of allergens from other legume species such as lupine, lentil, chickpea, green bean, or pea. As legumes are mainly consumed after thermal processing, knowledge about the effect of such processing on the allergenicity of legumes has increased during the last years. In the present review, recent advances in the identification of allergens from peanut, soybean, lupine, and other legume species are summarized and discussed. An overview of the most recently described effects of thermal processing on the allergenic properties of legumes is provided and the potential IgE cross-reactivity among members of the Leguminosae family is discussed.