Sensitisation to peach allergen Pru p 7 is associated with severe clinical symptoms in a Spanish population.

BACKGROUND: Pru p 7 has been reported as a major allergen in peach allergy, associated with severe clinical symptoms and related to IgE sensitisation to cypress pollen. The main objective of this study was to prospectively evaluate the frequency of sensitisation to Pru p 7 and its clinical relevance amongst pediatric patients with peach allergy in Madrid (Spain). METHODS: Patients with a history of IgE-mediated symptoms (oral allergy syndrome, urticaria/angioedema, rhinoconjunctivitis/asthma, gastrointestinal symptoms, or anaphylaxis) occurring within 2 h after peach intake or contact were prospectively recruited from February 2020 to September 2021. Skin tests, sIgE by ImmunoCAP® (Pru p 1, Pru p 3, Pru p 4, Pru p 7, and Cupressus arizonica) and oral food challenge (OFC) were performed. The study was approved by the local Ethics Committee (PI-4513). RESULTS: Ninety-two patients were included (53.3% male); median age, 10 (IQR 6.0-14.75) years. Seventy-four (80.4%) patients had a reaction after ingestion of fresh peach (25.0% from peel, 23.9% from pulp, and 44.6% from both). Fifteen (16.3%) patients were sensitised to Pru p 7. Upper airway symptoms, anaphylaxis, and grade 2 reactions were statistically more frequent in patients sensitised to Pru p 7. Seven (7.9%) patients presented with exercise as a cofactor, four of whom were sensitised to Pru p 7 (p = .001). Patients sensitised to Pru p 7 were significantly more likely to have a positive OFC result than patients who were not (p = .008). Four patients who reacted to peach at OFC were sensitised to Pru p 7. Specific IgE against Cupressus arizonica pollen was positive in 25 (62.5%) patients. CONCLUSIONS: Pru p 7 sensitisation was observed in 16.3% of our population and was related to severe reactions, upper airway symptoms, anaphylaxis, and the presence of an eliciting cofactor.

A European-Japanese study on peach allergy: IgE to Pru p 7 associates with severity.

BACKGROUND: Pru p 3 and Pru p 7 have been implicated as risk factors for severe peach allergy. This study aimed to establish sensitization patterns to five peach components across Europe and in Japan, to explore their relation to pollen and foods and to predict symptom severity. METHODS: In twelve European (EuroPrevall project) and one Japanese outpatient clinic, a standardized clinical evaluation was conducted in 1231 patients who reported symptoms to peach and/or were sensitized to peach. Specific IgE against Pru p 1, 2, 3, 4 and 7 and against Cup s 7 was measured in 474 of them. Univariable and multivariable Lasso regression was applied to identify combinations of parameters predicting severity. RESULTS: Sensitization to Pru p 3 dominated in Southern Europe but was also quite common in Northern and Central Europe. Sensitization to Pru p 7 was low and variable in the European centers but very dominant in Japan. Severity could be predicted by a model combining age of onset of peach allergy, probable mugwort, Parietaria pollen and latex allergy, and sensitization to Japanese cedar pollen, Pru p 4 and Pru p 7 which resulted in an AUC of 0.73 (95% CI 0.73-0.74). Pru p 3 tended to be a risk factor in South Europe only. CONCLUSIONS: Pru p 7 was confirmed as a significant risk factor for severe peach allergy in Europe and Japan. Combining outcomes from clinical and demographic background with serology resulted in a model that could better predict severity than CRD alone.

Phenotypes and Endotypes of Peach Allergy: What Is New?

Peach allergy is emerging as a common type of fresh-fruit allergy in Europe, especially in the Mediterranean area. The clinical manifestations of peach allergy tend to have a peculiar geographical distribution and can range from mild oral symptoms to anaphylaxis, depending on the allergic sensitization profile. The peach allergen Pru p 7, also known as peamaclein, has recently been identified as a marker of peach allergy severity and as being responsible for peculiar clinical features in areas with high exposure to cypress pollen. This review addresses the latest findings on molecular allergens for the diagnosis of peach allergy, the clinical phenotypes and endotypes of peach allergy in adults and children, and management strategies, including immunotherapy, for peach allergy.

Allergy to Gibberellin-Regulated Proteins (Peamaclein) in Children.

BACKGROUND: Gibberellin-regulated proteins (GRPs, Peamaclein) are allergens recently identified in plant-derived food allergy (FA), and little is known about the clinical manifestations of this allergic condition in the European population, especially in children. OBJECTIVE: Our study aimed to identify and characterize pediatric patients with pollen-FA due to GRP sensitization. METHODS: We retrospectively analyzed the charts of patients referred to the Allergy Unit of the Meyer Children's Hospital in Florence for suspected FA. Three main eligibility criteria based on the actual knowledge of GRP allergy were used to select patients deserving further investigations: (1) systemic reactions after consumption of fruit or an unknown culprit food, (2) positive skin prick tests to both cypress pollen and Pru p 3-enriched peach peel extracts, (3) negative in vitro test results for Pru p 3 serum-specific Immunoglobulin E (sIgE). We performed the in vitro test to determine the anti-rPru p 7 (Peamaclein) sIgE levels in the selected patients. RESULTS: We identified 10 pediatric patients with Pru p 7 allergy and described their characteristics. The use of our eligibility criteria showed a high accuracy in identifying these patients: 100% of the selected patients had positive in vitro results for Pru p 7. We therefore proposed a diagnostic algorithm for Pru p 7 allergy. CONCLUSION: This is the first case series of European pediatric patients with a demonstrated Peamaclein allergy. These findings broaden our knowledge on GRP allergy in pediatric populations and could help clinicians to suspect, diagnose, and manage this recently discovered plant-derived FA.

When the Frequencies of Sensitization and Elicitation of Allergic Reaction Do Not Correlate-The Case of Apple Gibberellin-Regulated Protein Tested in an Italian Population.

Background: The literature reports describing allergic symptoms against apples in the patients sensitized to the gibberellin-regulated proteins (GRPs) suggested the presence of an allergenic GRP in this fruit. Objective: This study aimed to assess the presence of a GRP protein in apples and investigate its allergenicity. Methods: The protein was isolated and identified by the classical biochemical methods. The bioinformatics tools were used for similar searches and molecular modeling. The immunological features were investigated using the multiplex FABER test. Clinical data were collected by the allergy specialists. Results: A GRP was detected in the apple peel and pulp and it was named applemaclein. This protein displays 94% of sequence identity with peamaclein, Pru p 7, representing the prototype of this allergen family. The applemaclein molecular model shows a very irregular surface with grooves/clefts that may potentially accommodate small molecular ligands. In a population of 4,721 patients in Italy, 187 (4.0%) were sensitized to any allergenic GPR. Of those, 115 (61.5%), 61 (32.6%), 30 (16.0%), and 99 (52.9%) had immunoglobulin E (IgE) to apple, peach, pomegranate, and cypress GRP, respectively. However, in a cohort of the patients in Italy, most individuals IgE positive to the apple GRP did not report allergic reactions against this fruit. Conclusion: Compared with the peach Pru p 7, applemaclein shows some different structural features and higher sensitization frequency, which is often not associated with allergic reactions against apple. Further studies are needed to understand a possible correlation between the applemaclein structural properties, the interaction with still unknown molecules, and immunological behavior.

Characterization of a 7 kDa pollen allergen belonging to the gibberellin-regulated protein family from three Cupressaceae species.

BACKGROUND: Severe allergy to fruits mediated by a 7 kDa allergen belonging to the gibberellin-regulated protein (GRP) family is known to be associated with Cupressaceae pollinosis. OBJECTIVE: To identify and characterize Cupressaceae pollen allergens involved in GRP-related fruit allergy. METHODS: Pru p 7-related proteins from pollen of Cupressus sempervirens, Juniperus ashei and Cryptomeria japonica were identified using a rabbit anti-Pru p 7 antiserum, purified chromatographically and sequenced by mass spectrometry and bioinformatic comparisons. The C sempervirens protein was produced as a recombinant allergen in Pichia pastoris. IgE antibody binding to pollen GRP proteins was analysed in a peach allergic (n = 54) and a cypress pollen allergic (n = 88) patient population from southern France using ImmunoCAP. RESULTS: In each of the three Cupressaceae species studied, a 7 kDa pollen protein related to Pru p 7 was identified and found to comprise an amino acid sequence of 63 residues in length, 92%-98% identical to each other and 67%-68% identical to Pru p 7. The C sempervirens, J ashei and C japonica GRP allergens have been officially recognized by the WHO/IUIS Allergen Nomenclature Sub-Committee and named Cup s 7, Jun a 7 and Cry j 7, respectively. Recombinant Cup s 7 showed IgE antibody binding capacity comparable to that of the purified natural allergen. Among 51 peach allergic subjects sensitized to Pru p 7, substantially higher levels of IgE to Cup s 7 than to Pru p 7 were found. Further, the pollen protein was able to completely outcompete IgE binding to Pru p 7, while the reverse competition effect was modest, consistent with primary sensitization by the pollen allergen. CONCLUSION AND CLINICAL RELEVANCE: Pru p 7-related pollen allergens from three Cupressaceae species have been characterized and may become useful for the identification of pollinosis patients at risk of developing severe fruit allergy.

Pru p 7 Predicts Severe Reactions after Ingestion of Peach in Japanese Children and Adolescents.

INTRODUCTION: Component-resolved diagnostics is used to diagnose food allergies. However, few reports have evaluated the severity of peach fruit allergy using peach allergen components, including Pru p 7. OBJECTIVE: This study aimed to predict peach fruit allergy severity based on the presence of specific IgE (sIgE) antibodies (Abs) to peach allergenic components. METHODS: Twenty-seven patients with peach fruit allergy were enrolled and classified into two groups: the local reaction (LR) group, including 12 patients with only oral or throat mucosal symptoms, and the systemic reaction (SR) group, including 15 patients, 10 of whom experienced anaphylaxis. Serum sIgE Abs against crude peach extract - Pru p 1, 2, 3, 4, and 7 - and tree pollen were measured. RESULTS: sIgE Ab titers of Pru p 1 and 4 and alder pollen in the LR group were significantly higher than those in the SR group. sIgE against Pru p 7 was significantly higher in the SR group than in the LR group. The frequencies of sIgE Abs against Pru p 1, 4, and 7 in the LR group were 91.7, 66.7, and 16.7%, respectively, while in the SR group these were 80, 20, and 60%. Sensitization to Pru p 2 and 3 was detected but limited in all patients. CONCLUSIONS: These findings suggest that sensitization to Pru p 1 and Pru p 4 is associated with local symptoms, and sensitization to Pru p 7 is associated with SR and anaphylaxis. To predict the severity of peach fruit allergy, it is useful to assess sIgE Ab reactions combining Pru p 1, 4, and 7.

Gibberellin-regulated protein allergy: Clinical features and cross-reactivity.

Gibberellin-regulated proteins (GRPs)/GASA proteins are members of cysteine-rich antimicrobial peptide families and are conserved in a broad range of plants. Some GRPs in fruits and pollens have been identified as allergens including peach Pru p 7, Japanese apricot Pru m 7, orange Cit s 7, pomegranate Pun g 7, and cypress pollen GRP. The clinical features of fruit-derived GRP allergies frequently include systemic reactions, multiple fruit allergies regardless of plant kingdom classifications and, less frequently, cofactor-dependence. Multiple fruit allergies might be related to cross-reactivity between GRPs. Clinical cross-reactivity, at least between the four fruit-derived GRPs, has been proven. In addition, GRP allergy induces peculiar clinical symptoms, such as laryngeal tightness and facial swelling, especially eyelid edema, which was proposed to be a predictive factor for Pru p 7 allergy. Fruit-derived GRPs have an unusually high content of cysteine, resulting in high stability to heat and resistance to digestive enzymes. Therefore, GRPs are considered "true" food allergens that induce severe allergic reactions. As an alternative mechanism of fruit-derived GRP allergies, cross-reactivity between fruit GRP and cypress pollen GRP, which might play a role as a sensitizer, is suspected. Taken together, these characteristics indicate GRPs are clinically relevant plant allergens. This review article summarizes our current knowledge of the clinical features and important aspects of GRP sensitization and allergy.

Isolation of cypress gibberellin-regulated protein: Analysis of its structural features and IgE binding competition with homologous allergens.

The presence in cypress pollen of an important allergen, belonging to the gibberellin-regulated protein (GRP) family, has been suggested for many years. However, it has never been isolated and sometimes the homologous peach allergen, Pru p 7, has been used as a surrogate to perform immunological investigations. The aim of this study has been the isolation and molecular characterization of the GRP contained in the Cupressus sempervirens pollen. This protein, named Cypmaclein, has been purified from the natural source using conventional biochemical methods consisting in different chromatographic separations. Cypmaclein has been identified by direct protein sequencing of the N-terminal region and of internal fragments of the molecule. In SDS-PAGE, its apparent molecular mass is slightly higher than that of Pru p 7. Nevertheless, the mass spectrometry experiments reveal that the exact molecular mass of Cypmaclein (6821.88 Da) is very close to that of Pru p 7 (6909.90 Da). Two regions of Cypmaclein have been sequenced providing 50% of its primary structure. A high overall sequence identity of Cypmaclein with all the analyzed GRP has been observed, although in the N-terminal region the high identity is limited to the homolog of Cryptomeria japonica. In circular dichroism experiments Cypmaclein produced a spectrum overlapping that of Pru p 7. However, the comparative analysis of Cypmaclein, Pru p 7 and Pun g 7 IgE reactivity revealed a behavior that was not completely overlapping, thus suggesting that the IgE epitopes are only partially shared. In single point highest inhibition achievable assays performed with the FABER test, Cypmaclein efficiently competed with the allergenic peach and pomegranate GRP in the binding of specific IgE of patients sensitized to Pru p 7. In conclusion, the natural cypress pollen GRP has been isolated for the first time, its structural features have been investigated and its cross-reactivity with Pru p 7 and Pun g 7 has been demonstrated. This protein is now available for further investigations aimed at understanding its clinical relevance in the allergy to cypress pollen. In addition, the prevalence of sensitization directly to Cypmaclein, and not limited to the homologs, can be defined.

Pru p 7 sensitization is a predominant cause of severe, cypress pollen-associated peach allergy.

BACKGROUND: Peach is a common elicitor of food allergic reactions. Peach-induced immediate reactions may occur as benign pollen-food syndromes, usually due to birch pollen-related PR-10 cross-reactivity in temperate climates, and as potentially severe primary food allergies, predominantly related to nsLTP Pru p 3 in Mediterranean regions. The newly described peach allergen Pru p 7 has gained recent attention as a potential peach allergy severity marker. Sensitization to Pru p 7 and its allergenic homologues of the gibberellin-regulated protein family occurs in areas with high Cupressaceae tree pollen exposure. OBJECTIVE: We sought to investigate the distribution, clinical characteristics and molecular associations of Pru p 7 sensitization among subjects with suspected peach allergy in different regions of France. METHODS: Subjects with suspected peach allergy (n = 316) were included. Diagnostic work-up was performed according to current guidelines, including open food challenge when required. IgE antibody measurements and competition experiments were performed using the ImmunoCAP assay platform. RESULTS: Sensitization to Pru p 7 was present in 171 (54%) of all subjects in the study and in 123 of 198 (62%) diagnosed as peach allergic, more than half of whom were sensitized to no other peach allergen. Frequency and magnitude of Pru p 7 sensitization were associated with the presence of peach allergy, the clinical severity of peach-induced allergic reactions and the level of cypress pollen exposure. Cypress pollen extract completely outcompeted IgE binding to Pru p 7. Pru p 7 was extremely potent in basophil activation tests. CONCLUSION AND CLINICAL RELEVANCE: A subtype of Cupressaceae pollinosis, characterized by Pru p 7 sensitization, can be an underlying cause of severe peach allergy.

Identification of gibberellin-regulated protein as a new allergen in orange allergy.

BACKGROUND: To date, three orange allergens have been reported. However, it is still unclear whether gibberellin-regulated proteins (GRPs), identified as new allergens in other fruit allergies, are also involved in orange allergy. OBJECTIVE: To investigate the allergenicity of orange GRP and to determine the clinical characteristics of patients with orange allergy who are sensitized to orange GRP. METHODS: We enrolled 14 patients (four men, 10 women, mean age: 29.6 years) who were diagnosed with orange allergy based on relevant clinical history, positive skin test, and/or positive challenge test. Orange GRP (molecular weight: 6941.6 Da) was purified by ion-exchange column chromatography. To test for orange GRP-specific IgE, we performed ELISA, basophil activation tests, and skin prick tests. Cross-reactivity of orange GRP with native peach allergen nPru p 7 and Japanese apricot nPru m 7 was analysed by ELISA inhibition assays. IgE specific for orange, grapefruit, and peach allergens rPru p 1, rPru p 3, and rPru p 4 was measured using ImmunoCAP. RESULTS: Twelve of the 14 patients (85.7%) were positive for orange GRP allergy in at least one test: 71.4% (10/14) were positive by ELISA, 50% (3/6) were positive in the basophil activation test, and 100% (4/4) were positive in the skin prick test. ELISA inhibition assays revealed cross-reactivity of orange GRP with both nPru p 7 and nPru m 7. The patients showed variable positivity for specific IgE against orange, grapefruit, rPru p 1, rPru p 3, and rPru p 4 (57.1%, 71.4%, 7.1%, 0%, and 21.4%, respectively). The most frequent symptoms of orange GRP allergy were facial swelling and oropharyngeal symptoms. CONCLUSIONS AND CLINICAL RELEVANCE: Orange GRP may be involved in orange allergy and may be a cross-reactive allergen between citrus fruits and the Rosaceae family of fruits.

Gibberellin-regulated protein in Japanese apricot is an allergen cross-reactive to Pru p 7.

BACKGROUND: Gibberellin-regulated protein (GRP, also known as peamaclein) was recently identified as a new marker allergen related to systemic reactions in peach allergy; however, its role in other fruit allergies is unknown. OBJECTIVE: To investigate the allergenicity of Japanese apricot (JA) GRP and clarify the clinical characteristics of JA allergy patients with GRP sensitization. METHODS: Seven patients (two males, five females, mean age 28.0 years) diagnosed with JA allergy based on relevant clinical history, positive skin test and/or challenge test were enrolled. JA GRP with a molecular weight of 6896.5 Da was purified by ion-exchange column chromatography. We performed enzyme-linked immunosorbent assay (ELISA), IgE-immunoblotting, basophil activating tests (BATs), and skin prick tests (SPTs) with purified JA GRP. To investigate the cross-reactivity between JA GRP and native Pru p 7 (nPru p 7), we performed ELISA inhibition tests. We measured specific IgE levels against apricot, peach, rPru p 1, rPru p 3, and rPru p 4 using ImmunoCAP. RESULTS: ELISA and IgE-immunoblotting using JA GRP showed positive reactions in six (85.7%) and seven (100%) patients, respectively. Five patients who provided informed consent for BATs and SPTs using JA GRP had positive results. In four patients who underwent ELISA inhibition tests using JA GRP and nPru p 7, IgE binding to one GRP inhibited binding to the other. The positivity for specific IgE against apricot, peach, rPru p 1, rPru p 3, and rPru p 4 was 14.3%, 57.1%, 0%, 0%, and 0%, respectively. Patients developed allergic reactions that were frequently accompanied with facial swelling, especially of the eyelids, which was dependent on cofactors, such as exercise. CONCLUSIONS AND CLINICAL RELEVANCE: These results indicated that GRP might be a causative allergen of JA allergy, whose onset frequently requires a cofactor, such as exercise, and might be cross-reactive between JAs and peaches.

High prevalence of sensitization to gibberellin-regulated protein (peamaclein) in fruit allergies with negative immunoglobulin E reactivity to Bet v 1 homologs and profilin: Clinical pattern, causative fruits and cofactor effect of gibberellin-regulated protein allergy.

Gibberellin-regulated protein (GRP) is a new allergen in peach allergy, with an amino acid sequence very well conserved through several botanical species. We investigated the allergenicity of GRP in fruit allergies other than peaches and identified the clinical characteristics of fruit allergy patients with GRP sensitization. One hundred consecutive Japanese patients with fruit allergies were enrolled in the present study. To identify the features of GRP sensitization, we selected patients with negative ImmunoCAP results for Bet v 1 homologs and profilin, which are marker allergens for pollen-food allergy syndrome (PFAS), or lipid transfer protein. These patients underwent specific immunoglobulin E measurements by enzyme-linked immunosorbent assay (ELISA) and skin prick tests (SPT) using purified nPru p 7. Twenty of 100 consecutive patients with fruit allergies had negative ImmunoCAP results for Bet v 1 homologs and profilin. Thirteen (65.0%) of the 20 patients had positive ELISA and/or SPT results using nPru p 7, whereas one of the 20 patients had positive ImmunoCAP results for Pru p 3. In 13 nPru p 7-sensitized patients, the causative foods were peaches (92.3%), apricots (61.5%), oranges (46.2%) and apples (30.8%). Ten patients (76.9%) had multiple causative fruits. Frequent symptoms included facial edema (92.3%) and laryngeal tightness (66.7%). In eight patients (61.5%), exercise or aspirin intake enhanced the allergic reaction onset as cofactors. The prevalence of GRP sensitization was high in Japanese fruit allergy patients except for PFAS patients. In conclusion, GRP-sensitized patients may have allergies to multiple fruits and may show peculiar characteristics such as facial swelling and cofactor dependence.

Pomegranate Cultivars: Identification of the New IgE-Binding Protein Pommaclein and Analysis of Antioxidant Variability.

The consumption of pomegranate is increasing as it is considered a health-promoting food. Nevertheless, it can trigger allergic reactions, sometimes severe. The LTP Pun g 1 is the only pomegranate allergen so far reported. Based on preliminary clinical observations, the main aim of this study was the investigation of still unknown allergens contained in this fruit. Pommaclein, a homologue of peamaclein, the peach allergen Pru p 7, was isolated, identified by protein sequencing, and characterized as an IgE-binding protein by different test systems. RP-HPLC protein profiles revealed significant variations of LTP and pommaclein content in the red pulp of selected cultivars and accessions. Conversely, the mesocarp appeared free of proteins and much richer in antioxidants. In conclusion, a new allergen has been identified, and it could contribute to improving allergy diagnosis. The study highlights that pomegranate mesocarp could represent a rich and safe source of nutraceuticals also for allergic subjects.

Eyelid edema as a predictive factor for sensitization to Pru p 7 in peach allergy.

The clinical and laboratory factors related to Pru p 7 sensitization in peach allergy, compared with those associated with sensitization to Pru p 1, which is related to pollen-food allergy syndrome (PFAS), have still not been clarified. The aim of the present study was to identify the clinical and laboratory features associated with sensitization to Pru p 7. Fifty patients (male : female, 14:36; mean age, 31.8 years) with peach allergy were enrolled in this study. Specific immunoglobulin E (sIgE) against the purified nPru p 7 was measured by enzyme-linked immunoassay, whereas using ImmunoCAP, sIgE levels against peach, rPru p 1, rPru p 3 and rPru p 4 were measured. Correlations between the clinical characteristics of peach allergy and sensitization to the allergens were statistically analyzed. In 50 patients with peach allergy, 13 and 33 patients were sensitized with nPru p 7 and rPru p 1, respectively. Laryngeal tightness, conjunctival injection, facial edema, eyelid edema and urticaria were significantly associated with Pru p 7 sensitization. In contrast, oropharyngeal symptoms were strongly related to Pru p 1 sensitization but were significantly less common in the Pru p 7-positive group. Co-sensitization to the representative pollens related to PFAS, such as alder pollens, was significantly related to Pru p 1 sensitization, but not Pru p 7 sensitization. Along with the absence of co-sensitization to pollens related to PFAS, facial edema and especially eyelid edema after the ingestion of peaches could be a predictive factor for sensitization to Pru p 7.

Structure, stability, and IgE binding of the peach allergen Peamaclein (Pru p 7).

Knowledge of the structural properties of allergenic proteins is a necessary prerequisite to better understand the molecular bases of their action, and also to design targeted structural/functional modifications. Peamaclein is a recently identified 7 kDa peach allergen that has been associated with severe allergic reactions in sensitive subjects. This protein represents the first component of a new allergen family, which has no 3D structure available yet. Here, we report the first experimental data on the 3D-structure of Peamaclein. Almost 75% of the backbone resonances, including two helical stretches in the N-terminal region, and four out of six cysteine pairs have been assigned by 2D-NMR using a natural protein sample. Simulated gastrointestinal digestion experiments have highlighted that Peamaclein is even more resistant to digestion than the peach major allergen Pru p 3. Only the heat-denatured protein becomes sensitive to intestinal proteases. Similar to Pru p 3, Peamaclein keeps its native 3D-structure up to 90°C, but it becomes unfolded at temperatures of 100-120°C. Heat denaturation affects the immunological properties of both peach allergens, which lose at least partially their IgE-binding epitopes. In conclusion, the data collected in this study provide a first set of information on the molecular properties of Peamaclein. Future studies could lead to the possible use of the denatured form of this protein as a vaccine, and of the inclusion of cooked peach in the diet of subjects allergic to Peamaclein.