AMINO-ACID-SEQUENCE OF A PEPTIDE WITH MOLT-INHIBITING ACTIVITY FROM THE KURUMA PRAWN PENAEUS-JAPONICUS

Six major peptides (Pej-SGP-I-VI) that belong to the CHH family have b een isolated from the sinus gland extracts of the kuruma prawn Penaeus japonicus. By in vitro assay using the Y-organ of the crayfish Procam barus clarkii, Pej-SGP-IV was found to be active in inhibiting ecdyste roid synthesis. We determined the complete amino acid sequence. Pej-SG P-IV consists of 77 amino acid residues, with both free aimno- and car boxyl-termini. The sequence of Pej-SGP-IV shows considerable similarit y to that of MIH of the shore crab Carcinus maenas and less similarity to Pej-SGP-III, whose sequence has been previously determined.