MOLECULAR-CLONING OF THE DEFENSE FACTOR IN THE ALBUMIN GLAND OF THE SEA HARE APLYSIA-KURODAI

Aplysianin-A, an antibacterial glycoprotein in the albumen gland of th e sea hare Aplysia kurodai, inhibited the growth of both Gram-positive and Gram-negative bacteria. Aplysianin-A cDNA clones were isolated fr om an albumen gland cDNA library. Sequence analysis reveals that aplys ianin-A is produced as a precursor protein of 556 amino acid residues with a signal peptide of 19 amino acid residues and contains 6 potenti al N-glycosylation sites, Aplysianin-A mRNA was expressed tissue-speci fically in the albumen gland, Homology search reveals that aplysianin- A has a 50% overall amino acid sequence homology to achacin, an antiba cterial glycoprotein of the giant African snail Achatina fulica.