title: Green bean (Phaseolus vulgaris): a new source of IgE-binding lipid transfer protein.
abstract: Green beans belong to the Fabaceae family, which includes widely consumed species, such as beans, peanuts, and soybeans. In the literature, few cases have described allergic reactions upon the exposure to green bean boiling steam or ingestion. Here, we describe five patients reporting documented adverse reactions upon the ingestion of cooked green beans, and we characterize the responsible allergen. Fresh and cooked green beans were tested by a prick + prick technique. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and IgE immunoblotting were performed with boiled vegetable extract, and the N-terminal sequence of the immunoreactive protein was obtained by analyzing the excised band in a protein sequencer. Immunoblotting inhibition of cooked green bean with in-house-purified peach lipid transfer protein (LTP) Pru p 3 was performed. An interesting green bean protein was chromatographically purified, tested with a pool serum, and inhibited with Pru p 3. Moreover, its molecular mass was determined by mass spectrometry. Prick + prick tests with raw and cooked green beans were positive for all of the patients. IgE immunoblotting showed that all of the patients reacted toward a unique IgE-binding protein at about 9 kDa. The obtained N-terminal sequence revealed the following amino acids: Ala-Ile-Ser-X-Gly-Qln-Val-Thr-Ser-Ser-Leu-Ala, corresponding to an LTP. A complete inhibition of the IgE binding to this protein, in both raw and purified extract, was obtained by purified peach Pru p 3, confirming previous IgE immunoblotting results.
authors.affiliation: Allergology and Immunology Unit, Niguarda Ca' Granda Hospital, Milan, Italy.
authors.forename: Elide A
authors.initials: EA
authors.lastname: Pastorello
authors.forename: Valerio
authors.initials: V
authors.lastname: Pravettoni
authors.forename: Laura
authors.initials: L
authors.lastname: Farioli
authors.forename: Laura
authors.initials: L
authors.lastname: Primavesi
authors.forename: Joseph
authors.initials: J
authors.lastname: Scibilia
authors.forename: Marta
authors.initials: M
authors.lastname: Piantanida
authors.forename: Ambra
authors.initials: A
authors.lastname: Mascheri
authors.forename: Amedeo
authors.initials: A
authors.lastname: Conti
mesh_terms: D000293:Adolescent; D000328:Adult; D000595:Amino Acid Sequence; D052179:Antigens, Plant / Q000276:immunology; D002352:Carrier Proteins / Q000737:chemistry / Q000276:immunology*; D005260:Female; D005512:Food Hypersensitivity / Q000276:immunology*; D006801:Humans; D007073:Immunoglobulin E / Q000737:chemistry / Q000276:immunology*; D008297:Male; D008969:Molecular Sequence Data; D027805:Phaseolus / Q000276:immunology*; D011485:Protein Binding; D055815:Young Adult
chemical_list: D052179:Antigens, Plant; D002352:Carrier Proteins; C030363:lipid transfer protein; D007073:Immunoglobulin E