Identification and sequence analysis of pyrokinin/PBAN peptide of psocids, Liposcelis entomophila

Abstract

Using an antiserum against Helicoverpa zea pheromone biosynthesis activating neuropeptide (PBAN), pyrokinin/PBAN-like immunoreactivity in the head and body of female of Liposcelis entomophila was detected by competitive ELISA. Pyrokinin/PBAN peptides were extracted and purified by reverse-phase HPLC, and the sequence were elucidated by a matrix-assisted laser desorption ionization time of flight mass spectrometer (MALDI-MS-TOF). The results showed that pyrokinin/PBAN neuropeptide was expressed in the heads of L. entomophila females. Meanwhile, it was not found in the abdomen of L. entomophila females and the head of Liposcelis bostrychophila. These results indicated that the peptide perhaps had the functions to regulate sex pheromone releasing. The sequence pyrokinin/PBAN family peptide in L. entomophila was SAGMFTPRL -NH2. The result of BLASTp in NCBI web showed that its sequence had largely homologous sequences with other PBAN/pyrokinin peptides sequence in other insects that were published and share a highly conserved sequence FXPRLamide in the C terminal. This result indicated that the identified peptide in L. entomophila belong to the pyrokinin/PBAN family. The purification and identification of this peptide have an important instructional meaning for cloning the gene of pyrokinin/PBAN and elucidating the release mechanism of the sex pheromone of L. entomophila.

Key words: Liposcelis entomophila, pyrokinin/PBAN, peptide.