TROPOMYOSIN, THE MAJOR OYSTER CRASSOSTREA-GIGAS ALLERGEN AND ITS IGE-BINDING EPITOPES

The major allergen (Cra g 1) isolated from the oyster Crassostrea giga s was digested with lysylendopeptidase, Twenty-one peptide fragments w ere Isolated from the digest by reverse-phase HPLC and some of them we re sequenced, Cra g 1 was identified as tropomyosin, In competitive EL ISA inhibition analyses of lysylendopeptidase fragments, a peptide (K2 1) showed maximum inhibition of the binding of IgE antibodies in sensi tive human serum to Cra g 1. On further tryptic hydrolysis of K21, two peptides exhibited high inhibitory ability equivalent to K21. These r esults suggested that Cra g 1 had an IgE-binding epitope in the segmen t 92-105 (IQLLEEDMERSEER) which was dissimilar to those of the major a llergen (tropomyosin) from the shrimp Penaeus indicus.