Kiwellin, a Modular Protein from Green and Gold Kiwi Fruits: Evidence of in Vivo and in Vitro Processing and IgE Binding

• Published in: Journal of agricultural and food chemistry Vol. 56; no. 10; pp. 3812 - 3817
• Main Authors: Tuppo, Lisa, Giangrieco, Ivana, Palazzo, Paola, Bernardi, Maria Livia, Scala, Enrico, Carratore, Vito, Tamburrini, Maurizio, Mari, Adriano, Ciardiello, M. Antonietta
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 28.05.2008
• Subjects: Actinidia; Actinidia - chemistry; Actinidia deliciosa; allergen; allergenicity; Amino Acid Sequence; amino acid sequences; Antigens, Plant; Antigens, Plant - chemistry; Antigens, Plant - isolation & purification; Antigens, Plant - metabolism; Biological and medical sciences; chemistry; Food Chemistry/Biochemistry; Food industries; Fruit; Fruit - chemistry; Fruit and vegetable industries; fruit crops; Fundamental and applied biological sciences. Psychology; General aspects; immunoglobulin E; Immunoglobulin E - metabolism; in vitro studies; isolation & purification; kissper; KiTH; Kiwellin; kiwi fruit; kiwifruit; metabolism; Methods of analysis, processing and quality control, regulation, standards; Molecular Sequence Data; molecular weight; peptides; plant extracts; Plant Extracts - chemistry; plant proteins; protein binding; protein processing; protein subunits; proteinases; proteolysis; Sequence Analysis, Protein; Kiwellin; kiwi fruit; KiTH; allergen; protein processing; Binding; Immunoglobulins; Fruit; IgE; In vitro; Protein; In vivo; Kiwi (fruit); Green; Allergen
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf703620m

Kiwellin, an allergenic protein formerly isolated from green kiwi fruit, has been identified as the most abundant component of the gold kiwi species. A protein named KiTH, showing a 20 kDa band on reducing SDS-PAGE and 100% identity with the C-terminal region of kiwellin, has been identified in the extract of the ripe green species. In vitro treatment of purified kiwellin with the protease actinidin from green kiwi fruit originated KiTH and kissper, a recently described pore-forming peptide. Primary structure analysis and experimental evidence suggest that kiwellin is a modular protein with two domains. It may undergo in vivo proteolytic processing by actinidin, thus producing KiTH and kissper. When probed with sera recognizing kiwellin from green kiwi fruit, KiTH showed IgE binding, with reactivity levels sometimes different from those of kiwellin. The IgE-binding capacity of kiwellin from gold kiwi fruit appears to be similar to that of the green species.