A cDNA library was constructed from the Korean native leeches, Hirudo nipponia using the PCR-directed method.
A full-length cDNA encoding guamerin was isolated from the cDNA library and nucleotide sequence was analyzed. The cDNA contained an open reading frame of 228 bp which encoded a 75 amino acid protein. The guamerin precursor consisted of additional 5 amino acid residues at N-terminal region and 13 amino acid residues at C-terminal region. The mature guamerin consisted of 57 amino acids.
The deduced amino acid sequence revealed a different amino acid residue from that of guamerin.
This cDNA has 71 % local identity to cDNA of antistasin, factor Xa inhibitor derived leech, Haementaria officialis at the DNA level.