title: Structural features, IgE binding and preliminary clinical findings of the 7kDa Lipid Transfer Protein from tomato seeds.
abstract: Allergic reactions caused by 9kDa Lipid Transfer Proteins (9k-LTP), such as Pru p 3, have been widely investigated, whereas a possible contribution of components of 7kDa LTP (7k-LTP) sub-family in triggering allergic symptoms has been overlooked so far. With the aim to investigate the contribution of 7k-LTPs to the food allergies, we have identified, isolated and characterised a tomato seed 7k-LTP (Sola l 7k-LTP). The protein was purified by chromatographic separations, identified by direct protein sequencing and mass spectrometry and a molecular model was built. Functional evaluation of the allergen has been performed by skin testing. Sola l 7k-LTP consists of 68 amino acids producing a molecular mass of 7045Da and displays 41% sequence identity with Pru p 3, the allergenic 9k-LTP from peach. IgE antibodies specifically recognising Sola l 7k-LTP were found within the population claiming tomato ingestion-related symptoms, but also in subjects tolerant on tomato exposure. A few subjects were mono-sensitised to Sola l 7k-LTP, which is biologically active as shown by the positive skin test. In line with the immunological results, the molecular model shows structural similarities between the IgE binding regions of the two sub-families. Therefore, Sola l 7k-LTP shares some structural and immunological features with Pru p 3, but it also displays individual features that could be responsible for mono-specific IgE binding. In conclusion, Sola l 7k-LTP is a new identified allergenic LTP, the description of which may contribute to the improvement of allergy diagnosis and to the formulation of a safe and personalised diet. In addition, to avoid current confusing classifications, a new nomenclature policy for LTP sub-families is proposed in this paper. We now suggest that 7-kDa LTP (so far named LTP2) be renamed 7k-LTP and 9-kDa LTP (so far named LTP1) be renamed 9k-LTP.
authors: Institute of Biosciences and BioResources, CNR, Via Pietro Castellino 111, I-80131 Naples, Italy.
authors: Ivana
authors: I
authors: Giangrieco
authors: Center for Molecular Allergology, IDI-IRCCS, Rome, Italy; Associated Centres for Molecular Allergology, Rome and Latium, Italy.
authors: Claudia
authors: C
authors: Alessandri
authors: Center for Molecular Allergology, IDI-IRCCS, Rome, Italy; Associated Centres for Molecular Allergology, Rome and Latium, Italy.
authors: Chiara
authors: C
authors: Rafaiani
authors: Center for Molecular Allergology, IDI-IRCCS, Rome, Italy; Associated Centres for Molecular Allergology, Rome and Latium, Italy.
authors: Mario
authors: M
authors: Santoro
authors: Center for Molecular Allergology, IDI-IRCCS, Rome, Italy; Associated Centres for Molecular Allergology, Rome and Latium, Italy.
authors: Sara
authors: S
authors: Zuzzi
authors: Institute of Biosciences and BioResources, CNR, Via Pietro Castellino 111, I-80131 Naples, Italy.
authors: Lisa
authors: L
authors: Tuppo
authors: Institute of Biosciences and BioResources, CNR, Via Pietro Castellino 111, I-80131 Naples, Italy.
authors: Maurizio
authors: M
authors: Tamburrini
authors: Institute of Biosciences and BioResources, CNR, Via Pietro Castellino 111, I-80131 Naples, Italy.
authors: Rossana
authors: R
authors: D'Avino
authors: Institute of Biosciences and BioResources, CNR, Via Pietro Castellino 111, I-80131 Naples, Italy.
authors: Maria Antonietta
authors: MA
authors: Ciardiello
authors: Center for Molecular Allergology, IDI-IRCCS, Rome, Italy; Associated Centres for Molecular Allergology, Rome and Latium, Italy. Electronic address: adriano.mari@caam-allergy.com.
authors: Adriano
authors: A
authors: Mari
mesh_terms: D000293:Adolescent; D000328:Adult; D000595:Amino Acid Sequence; D052179:Antigens, Plant / Q000737:chemistry / Q000276:immunology; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification; D002648:Child; D002675:Child, Preschool; D005260:Female; D005512:Food Hypersensitivity / Q000276:immunology* / Q000503:physiopathology; D006801:Humans; D007073:Immunoglobulin E / Q000737:chemistry / Q000276:immunology*; D018551:Solanum lycopersicum / Q000737:chemistry / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D008958:Models, Molecular; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010940:Plant Proteins / Q000737:chemistry / Q000276:immunology* / Q000302:isolation & purification; D011485:Protein Binding; D011487:Protein Conformation; D027861:Prunus / Q000737:chemistry / Q000276:immunology; D012639:Seeds / Q000737:chemistry / Q000276:immunology*; D016415:Sequence Alignment; D009626:Terminology as Topic
chemical_list: D052179:Antigens, Plant; D002352:Carrier Proteins; C109356:LTP2 protein, plant; D010940:Plant Proteins; C463181:Pru p 3 allergen; D007073:Immunoglobulin E
keywords: 7kDa LTP; Food allergy; IgE reactivity; Molecular model; Solanum lycopersicum; Tomato seeds