Identification and characterization of a basic thaumatin‐like protein (TLP 2) as an allergen in sapodilla plum (Manilkara zapota). Issue 4 (5th December 2013)

• Record Type: Journal Article
• Authors: Hegde, Venkatesh L.; Ashok Kumar, Hassan G.; Sreenath, Kundimi; Hegde, Muralidhar L.; Venkatesh, Yeldur P.
• Is Part Of: Molecular nutrition & food research. Volume 58:Issue 4(2014:Apr.)
• Page Start: 894
• Page End: 902
• Publication Date: 2013-12-05
• Subjects: Food -- Biotechnology -- Periodicals; Food -- Microbiology -- Periodicals; Nutrition -- Periodicals; Food -- Toxicology -- Periodicals; Nutrition -- Periodicals; Food Microbiology -- Periodicals; Food Technology -- Periodicals; Molecular Biology -- Periodicals; 664.0705
• DOI: 10.1002/mnfr.201300261
• Languages: English
• ISSNs: 1613-4125

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="mnfr2122-sec-0010" sec-type="section"> <title>Scope</title> <p>Cases of oral allergy syndrome following the ingestion of sapodilla plum (<italic>Manilkara zapota</italic>) have been reported rarely. As the causative allergens are not known, the main objective of this study was to identify and characterize the important allergens in sapodilla.</p> </sec> <sec id="mnfr2122-sec-0020" sec-type="section"> <title>Methods and results</title> <p>Allergy to sapodilla was diagnosed by case history, skin prick test, and serum allergen–specific IgE. The allergen was detected by IgE immunoblotting, purified on SP–Sepharose and characterized by native/SDS–PAGE, IEF, MS, and amino acid composition. Several cases of allergy to sapodilla fruit were identified; majority of the sapodilla‐allergic subjects (6/7) experienced typical oral allergy syndrome symptoms, and allergen–specific IgE to the purified protein was positive. The allergen has a p<italic>I</italic> ≥9.5 and high contents of arginine, threonine, glycine, and cysteine. Circular dichroism revealed a secondary structure rich in beta sheets/turns. Based on its <italic>N</italic>‐terminal sequence of A‐T‐F‐D‐I‐Q‐N‐N‐C‐X‐Y‐, the allergen (21 578 Da) was identified as a thaumatin‐like protein by homology.</p> </sec> <sec id="mnfr2122-sec-0030" sec-type="section"> <title>Conclusion</title> <p>The causative allergen in sapodilla plum has been identified and characterized as a highly basic thaumatin‐like protein belonging to the pathogenesis‐related protein (PR–5) family, which has been recognized as a new family of conserved, cross‐reactive plant allergens.</p> </sec> </abstract>