A NOVEL ACIDIC ALLERGEN, HEV-B-5, IN LATEX - PURIFICATION, CLONING AND CHARACTERIZATION

Latex allergy is recognized as a serious health problem among health c are workers and children with spina bifida, A number of IgE-reactive p roteins have been identified in natural and processed latex products. One of the most acidic proteins in the cytoplasm of lacticifer cells o f rubber trees (Hevea brasiliensis) is demonstrated to be a potent all ergen in eliciting allergic reactions in humans, This protein, with pI = 3.5, has a molecular mass of 16 kDa with a blocked N terminus and a n unusual amino acid composition, This acidic protein was found in ext racts prepared from latex gloves, which were shown to be allergenic, T he purified protein elicits histamine release from human basophils pas sively sensitized with serum from latex-allergic individuals in a dose dependent manner. From a latex cDNA library, the cDNA coding for this protein was isolated and sequenced. The deduced amino acid sequence s hows a high degree of homology to another acidic protein identified in kiwifruit (Actinidia deliciosa var. deliciosa). The sequence homology (47% sequence identity) between these two acidic proteins suggests a molecular explanation for the high frequency of fruit hypersensitivity in latex-allergic patients.