THE PRIMARY STRUCTURE OF UK114 TUMOR-ANTIGEN

UK114 is a tumor antigen expressed by various malignant neoplasms, The complete amino acid sequence of UK114 purified from goat liver has be en determined by automated Edman degradation of CNBr and endoproteinas e Lys-C peptides, The protein contains 137 amino acid residues, which corresponds to a molecular mass of 14 229 Da, MALDI-TOF analysis resul ted in a molecular weight of 14290, suggesting that the N-terminal Met residue is acetylated. Sequence comparison shows that UK114 from goat liver (1) has 77% identity with a previously described 23 kDa protein from rat liver (Levy-Favatier et al, (1993) Eur. J. Biochem. 212, 665 -673), (2) shares a very high degree of similarity with a family of pr okaryotic and eukaryotic hypothetic proteins whose function have not y et been characterized, and (3) exhibits a significant similarity to a group of tumor-associated antigens which belongs to a superfamily of h eat shock proteins, acting as possible targets for the host's antitumo r immunity.