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Distribution of α-amylase and protease activities in the whole body extract and faecal extract of A. siro (A.s.) and D. farinae (D.f.). The α-amylase activities were assayed at the respective pH optima with RBB-starch as a substrate. The protease activities were assayed with azocasein as a substrate; the contribution of cysteine proteases (dashed) was determined as the part of protease activity inhibited by E-64. The specific activities (units per mg protein) are normalized to the maximum value measured for α-amylases and proteases, respectively; mean values ± SE are given.
Source publication
Enzymatic allergens of storage mites that contaminate stored food products are poorly characterized. We describe biochemical and immunological properties of the native alpha-amylase allergen Aca s 4 from Acarus siro, a medically important storage mite.
A. siro produced a high level of alpha-amylase activity attributed to Aca s 4. This enzyme was pu...
Citations
... Mites are an important pest of stored agricultural products globally (Xia et al. 2009;Mangoba and Alvindia., 2019a). Their presence is significant in the economy, hygiene, and human health (Pytelkova et al. 2012). The S. pontifica is amongst the most frequent stored product mite in major agricultural provinces in the Philippines (Mangoba and Alvindia., 2019a). ...
... The S. pontifica is amongst the most frequent stored product mite in major agricultural provinces in the Philippines (Mangoba and Alvindia., 2019a). They infest a range of stored goods, like maize, rice, wheat, flour, and their byproducts, and they undergo parthenogenetic stage (Balmes-Pacia and Raros 1998) and have gained economic relevance as the most common source of allergen in humans that cause allergies like rhinitis and eczema (Pytelkova et al. 2012). Furthermore, it is a substantial factor to what is known as oral mite anaphylaxis (OMA) or "pancake syndrome" (Barrera et al. 2015). ...
The present study aims to assess the bioactivity of guava leaf extract (GLE) against Suidasia pontifica, a stored grain mite. The current study aimed to analyze the chemical components and miticidal effect of GLE against the S. pontifica population. The generated information can be used in organic agriculture practices and promoting the utilization of natural products in managing stored product mite. Based on the biological responses of the test mite, the projected minimum effective concentration (MEC) of GLE that provides 100% mortality of mite population was 1.75 g/L. Fifty-four compounds were detected in GLE under GCMS analysis. The major constituents were the following: oleyl alcohol methyl ether (13.91%), γ-sitosterol (13.05%), globulol (8.26%), 10,10-dimethyl-2,6-dimethylenebicyclo[7.2.0]undecane (7.45%), α-terpineol (5.13%), and β-caryophyllene (4.58%). Meanwhile, GLE (1.75 g/L) is generally superior in volume concentration and potency to commercially available miticides in the market (coumaphos 2.00 g/L) regarding mite population control. It shows that the main chemical and other derivatives of GLE may have cooperated synergistically, augmenting the toxic activity that leads to death.
... Interestingly, aside the typical fungal subfamily GH13_1, this residue is also not invariantly conserved even in the animal α-amylase subfamily GH13_24 ( Figure S1), for members of which the activation by chloride anion has been well documented [42]. This asparagine is replaced by a serine in mites from Acarus siro ( [55]; GenBank: ABL09312.1), Dermatophagoides pteronyssinus ( [56]; AAD38942.1) ...
This study brings a detailed bioinformatics analysis of fungal and chloride-dependent α-amylases from the family GH13. Overall, 268 α-amylase sequences were retrieved from subfamilies GH13_1 (39 sequences), GH13_5 (35 sequences), GH13_15 (28 sequences), GH13_24 (23 sequences), GH13_32 (140 sequences) and GH13_42 (3 sequences). Eight conserved sequence regions (CSRs) characteristic for the family GH13 were identified in all sequences and respective sequence logos were analysed in an effort to identify unique sequence features of each subfamily. The main emphasis was given on the subfamily GH13_32 since it contains both fungal α-amylases and their bacterial chloride-activated counterparts. In addition to in silico analysis focused on eventual ability to bind the chloride anion, the property typical mainly for animal α-amylases from subfamilies GH13_15 and GH13_24, attention has been paid also to the potential presence of the so-called secondary surface-binding sites (SBSs) identified in complexed crystal structures of some particular α-amylases from the studied subfamilies. As template enzymes with already experimentally determined SBSs, the α-amylases from Aspergillus niger (GH13_1), Bacillus halmapalus, Bacillus paralicheniformis and Halothermothrix orenii (all from GH13_5) and Homo sapiens (saliva; GH13_24) were used. Evolutionary relationships between GH13 fungal and chloride-dependent α-amylases were demonstrated by two evolutionary trees—one based on the alignment of the segment of sequences spanning almost the entire catalytic TIM-barrel domain and the other one based on the alignment of eight extracted CSRs. Although both trees demonstrated similar results in terms of a closer evolutionary relatedness of subfamilies GH13_1 with GH13_42 including in a wider sense also the subfamily GH13_5 as well as for subfamilies GH13_32, GH13_15 and GH13_24, some subtle differences in clustering of particular α-amylases may nevertheless be observed.
... Aca s 4 was recognized by IgE from house dust mite-sensitive patients, and potential epitopes for cross-reactivity with house dust mite group 4 allergens were found. [29]. ...
Background and aim: Progress in laboratory diagnostics of IgE-mediated allergy is the use of component-resolved diagnosis. Our study analyses the results of specific IgE to 295 allergen reagents (117 allergenic extracts and 178 molecular components) in patients suffering from atopic dermatitis (AD) with the use of ALEX2 Allergy Explorer. Method: The complete dermatological and allergological examination, including the examination of the sensitization to molecular components with ALEX2 Allergy Explorer testing, was performed. The statistical analysis of results was performed with these methods: TURF (total unduplicated reach and frequency), best reach and frequency by group size, two-sided tests, Fisher’s exact test, and chi-square test (at an expected minimum frequency of at least 5). Results: Altogether, 100 atopic dermatitis patients were examined: 48 men, 52 women, the average age 40.9 years, min. age 14 years, max. age 67 years. The high and very high level of specific IgE was reached in 75.0% of patients to 18 molecular components: from PR-10 proteins (Aln g 1, Bet v 1, Cor a1.0103, Cor a1.0401, Fag s 1), lipocalin (Can f 1), NPC2 family (Der f 2, Der p 2), uteroglobin (Fel d 1), from Alternaria alternata (Alt a 1), Beta expansin (Lol p 1, Phl p 1), molecular components from Timothy, cultivated rye (Secc pollen) and peritrophin-like protein domain Der p 23. The high and very high level of specific IgE to other lipocalins (Fel d 7, Can f 4), to arginine kinase (Bla g 9, German cockroach), and to allergen extracts Art v (mugwort), and Cyn d (Bermuda grass) reached 52.0% of patients. The severity of AD is in significant relation to the sensitization to molecular components of storage mites (Gly d 2, Lep d 2—NPC2 family), lipocalins (Can f 1, Can f 2, Can f 4, and Can f 6), arginine kinase (Asp f 6, Bla g 9, Der p 20, Pen m 2), uteroglobin (Fel d 1, Ory c 3), Mn superoxide dismutase (Mala s 11), PR-10 proteins (Fag s 1, Mal d 1, Cor a 1.0401, Cor a 1.0103), molecular components of the peritrophin-like domain (Der p 21, Der p 23), and to Secc pollen. In the subgroup of patients suffering from bronchial asthma, the significant role play molecular components from house dust mites and storage mites (Lep d 2, Der p 2, Der f 2—NPC2 family), cysteine protease (Der p 1), peritrophin-like protein domain (Der p 21, Der p 23), enolase from Alternaria alternata (Alt a 6), and Beta expansin Phl p 1. Conclusion: The results of our study demonstrate the detailed profile of sensitization to allergens reagents (allergen extract and molecular components) in patients with atopic dermatitis. We show the significance of disturbed epidermal barrier, resulting in increased penetration of allergens. We confirmed the significant relationship between the severity of AD, the occurrence of bronchial asthma and allergic rhinitis, and high levels of specific IgE to allergen reagents. Our results may be important for regime measures and immunotherapy; Der p 23 shall be considered as an essential component for the diagnosis and specific immunotherapy of house dust mite allergy.
... Blo t 4 is an allergen homologous to amylase, with 68% aa sequence identity with group 4 allergen of Dermatophagoides [57] and A. siro. Aca s 4 has a high level of α-amylase activity and 74%, 70%, 64%, and 66% sequence similarity with Tyr p 4, Blo t 4, Eur m 4, and Der p 4, respectively [58]. ...
... 21 The extracts produced by different European manufacturers are not usually interchangeable. 22 In United States, ID50EAL (intradermal dilution for 50 mm sum of erythema), is used to determine the potency of mite extracts as reference preparations. The Center for Biologics Evaluations and Research (CBER) of the FDA provides the reference extracts to the manufacturers and authorized products are compared with the references using the relative potency value obtained by a parallel-line bioassay analysis. ...
House dust mite (HDM) is a predominant source of indoor aeroallergen worldwide, which induces allergic diseases including allergic rhinoconjunctivitis, allergic asthma, atopic eczema and other allergic skin diseases. Allergen specific immunotherapy (AIT) is the only potential disease-modifying treatment for HDM allergic subjects. However, AIT remains underused due to no universally accepted allergen standardization and a shortage of rigorous clinical studies to confirm safety and efficacy. With the effort of doctors and researchers in allergy field, efficacy, safety, standardization and strategy of AIT are being continuously developed. This review presents the updated research based on recently published trials and meta-analyses.
... After the system was gradually heated to 300 K over 50 ps and equilibrated for 200 ps, a production run of 17 ns ensued, using previously published settings [15]. Thereafter, C391-C397 disulfide bond was formed using protocol we developed previously [16]. Briefly, 2 ns MD was run using harmonic restraints of 1, 5, 10, 20, 30, 40, and 50 kcal/mol/Å on the distance between the side chain sulfurs (SG. . ...
Mycobacterium tuberculosis (MTb), the causative agent of tuberculosis, can persist in macrophages for decades, maintaining its basic metabolic activities. Phosphoenolpyruvate carboxykinase (Pck; EC 4.1.1.32) is a key player in central carbon metabolism regulation. In replicating MTb, Pck is associated with gluconeogenesis, but in non-replicating MTb, it also catalyzes the reverse anaplerotic reaction. Here, we explored the role of selected cysteine residues in function of MTb Pck under different redox conditions. Using mass spectrometry analysis we confirmed formation of S–S bridge between cysteines C391 and C397 localized in the C-terminal subdomain. Molecular dynamics simulations of C391-C397 bridged model indicated local conformation changes needed for formation of the disulfide. Further, we used circular dichroism and Raman spectroscopy to analyze the influence of C391 and C397 mutations on Pck secondary and tertiary structures, and on enzyme activity and specificity. We demonstrate the regulatory role of C391 and C397 that form the S–S bridge and in the reduced form stabilize Pck tertiary structure and conformation for gluconeogenic and anaplerotic reactions.
... conserved IgE-binding epitope for the cross-reactivity of mite group 4 allergens was described (18). Therefore, it is necessary to investigate the cross-reactivity between cockroach amylase and other allergenic amylases from different species. ...
Periplaneta americana cockroach is an important source of inhalant indoor allergen resource, there are more than twenty IgE-binding components identified in P. americana, but only 9 allergens were characterized. Our knowledge about cockroach allergens remains poor. In this work, two novel allergen proteins Per a 11 (alpha-amylase) and Per a 12 (chitinase) with molecular weight around 55 and 45 kDa, respectively, were purified and characterized from the midgut of cockroaches. Their primary sequences were determined by Edman degradation, mass spectrometry and cDNA cloning. Sera from 39 and 30 of 47 (83.0% and 63.8%) patients reacted to Per a 11 and Per a 12 on immunoblots, respectively. The allergenicity of Per a 11 and Per a 12 was further confirmed by competitive ELISA, basophil activation test (BAT) and skin prick test (SPT). They appear to be of importance for the allergic reactions induced by cockroach, and have a potential for component-based diagnosis of allergy.This article is protected by copyright. All rights reserved.
... Group 4 allergens are alpha amylases found in faeces. 37 They have high sequence conservation that could cause confounding cross reactivities. D. pteronyssinus has 86% identity with D. farinae and 65% with storage mites compared to a 30e40% for most other allergens. ...
The allergenic load of house dust mite allergy is largely constituted by a few proteins with a hierarchical pattern of allergenicity. The serodominant specificities are the group 1&2 and the group 23 faecal allergens. The collective IgE binding to the group 1&2 allergens can measure unequivocal HDM sensitisation better than HDM extracts although discrepancies have been found in regions with complex acarofauna suggesting a need to investigate the specificity with allergen components. The group 4, 5, 7&21 allergens that each induce responses in about 40% of subjects are mid-tier allergens accounting for most of the remaining IgE binding. Their titres are proportional to the concomitant responses to Der p1&2. Group 2 allergen variants have different antibody binding. Body proteins only occasionally induce sensitisation although a higher prevalence of binding by atopic dermatitis patients provides a new avenue of research. A broad spectrum of IgE binding has been associated with diverse symptoms but not with the severity of asthma which is associated with low IgG antibody. Some allergens such as the group 14 large lipid binding proteins and the recently described proteins Der f 24–33, need further investigation but with the cognoscence that other denominated allergens have been found to be minor sensitisers by comparative quantitative analyses. Scabies is a confounder for diagnosis with extracts, inducing cross-reactive antibodies with Der p 4&20 as is seafood allergy with cross reactivity to Der p 10 a minor HDM allergen. The HDM genome sequence can now be used to verify allelic and paralogous variations.
... Several allergens have been obtained by molecular cloning. Aca s 4 has a high level of α-amylase activity and 74%, 70%, 64%, and 66% sequence similarity with Tyr p 4, Blo t 4, Eur m 4, and Der p 4, respectively [125]. A protein of 15 kDa homologous with several other FABP allergens also has been identified, isolated, cloned, sequenced, and expressed as a recombinant protein. ...
Allergic diseases triggered by mite allergens include allergic rhinoconjunctivitis, asthma, atopic dermatitis and other skin diseases. Since the early discovery of the allergenic role of mites of the genus Dermatophagoides in the mid 1960s, numerous species have been described as the source of allergens capable of sensitizing and inducing allergic symptoms in sensitized and genetically predisposed individuals. The main sources of allergens in house dust worldwide are the fecal pellets of the mite species D. pteronyssinus, D. farinae, Euroglyphus maynei and the storage mites Blomia tropicalis, Lepidoglyphus destructor and Tyropahgus putrescentiae. Group 1 and 2 allergens are major house dust mite allergens. The main allergens in storage mites include fatty acid-binding proteins, tropomyosin and paramyosin homologues, apolipophorin-like proteins, α-tubulins and others, such as group 2, 5 and 7 allergens. Cross-reactivity is an important and common immunological feature among mites. Currently, purified native or recombinant allergens, epitope mapping, proteomic approaches and T cell proliferation techniques are being used to assess cross-reactivity. Mites contain potent enzymes capable of degrading a wide range of substrates. Most mite allergens are enzymes. Advances in genomics and molecular biology will improve our ability to understand the genetics of specific IgE responses to mites. Mite allergen avoidance and immunotherapy are the only two allergen-specific ways to treat mite-induced respiratory and cutaneous diseases. © 2014 S. Karger AG, Basel.
... To date, a single allergen, Aca s 13 (a fatty acid binding protein) from A. siro has been characterized (Eriksson et al. 1999) and officially listed in the WHO/IUIS allergen nomenclature database (www.allergen.org). Recently, Aca s 4 (a-amylase) was characterized, but it is not listed in WHO/IUIS allergen nomenclature database (Pytelkova et al. 2012). Allergens of 18, 19, 25, and 27 kDa have been reported to be the crossreactive allergens (Han et al. 1999). ...
Although specific IgE to the storage mite Acarus siro is often detected, there are no detailed studies on IgE reactivity to A. siro in Korea. This study was undertaken to investigate the cross-reactivity to the mite species Dermatophagoides pteronyssinus, Dermatophagoides farinae, Tyrophagus putrescentiae, and A. siro in Korean mite allergic patients. Specific IgE values were determined for the four mite species and a competitive inhibition test was performed for mite extracts using the ImmunoCAP system. The IgE value to D. farinae was the highest among the four mite species tested. There was a strong correlation in the IgE value between house dust mites (D. pteronyssinus and D. farinae) and between storage mites (A. siro and T. putrescentiae). IgE reactivity to A. siro was inhibited by D. farinae and T. putrescentiae extract. Dermatophagoides farinae extract was the strongest inhibitor of IgE binding to A. siro extract, indicating that IgE reactivity to A. siro extract is a cross-reaction caused by sensitization to D. farinae. Strong IgE reactive components were observed in D. farinae and T. putrescentiae extract by SDS-PAGE and IgE immunoblotting. However, no strong IgE-binding component was observed for A. siro. Dermatophagoides farinae is the main source of mite allergens that cause sensitization in Korea. Serum IgE from some of the house dust mite-sensitized patients showed positive responses to storage mite allergens by cross-reaction. Therefore, it is necessary to pay special attention to the diagnosis of mite allergies.
