AMINO-ACID-SEQUENCE SIMILARITY OF HEV-B 3 TO 2 PREVIOUSLY REPORTED 27-KDA AND 23-KDA LATEX PROTEINS ALLERGENIC TO SPINS BIFIDA PATIENTS

Separate studies have reported spina bifida patients to be especially allergic to proteins of 27 and 23 kDa found in the serum of centrifuge d natural rubber latex. An insoluble latex protein located on the surf ace of small rubber particles, Hev b 3, has similarly been found to be allergenic to spina bifida patients. In this study, internal amino ac id sequences of Hev b 3 showed similarity to the published sequences f or the 27- and 23-kDa latex proteins. The latter allergens are hence i dentified as Hev b 3. Determination of the molecular weight of Hev b 3 revealed various species of 22-23 kDa. The consistent gaps of about 2 66 Da observed between various forms of the intact protein suggest tha t the protein undergoes post-translational modification. To determine whether Hev b 3 also occurs in a soluble form in the latex serum, its presence in molecular-filtered serum was checked by ELISA and Western blot. The results showed Hev b 3 to be largely absent in the C-serum f rom fresh latex. The protein is therefore insoluble in its native stat e. However, a small amount of the solubilized protein was detected in ammonia-stabilized latex (commonly used in the manufacture of latex pr oducts).