Isolation and characterization of the novel lipophilic protein, PbCP-12.7,from the shell of the pink shrimp, Pandalus borealis

Past research on diapause-inducing substances of the silkworm has isolated an extremely lipophilic peptide and demonstrated its unique characteristics . In the present work, similar lipophilic proteins were searched for in the shell of the shrimp, Pandalus borealis, and one novel protein, Pb CP-12.7, was isolated. Its structure comprising 126 amino acids was revealed by a c ombination of a sequence analysis and the enzymic fragmentation technique. Pb CP-12.7 is unique in that it was insoluble in neutral-slightly basic wat er, but highly soluble in some organic solvents. It contained an abundance of hydrophobic amino acids and repeating sequences. In addition, it was ads orbed to chitin, a major component of the shell of the shrimp.