Characterizing the Hez-PBAN gene products in neuronal clusters with immunocytochemistry and MALDI MS

Methods to characterize pheromone biosynthesis activating neuropeptide (PBAN) and other PBAN gene encoded neuropeptides (PGN) from individual subesophageal ganglion neuronal clusters of the corn earworm moth, Helicoverpa zea, were developed. Individual antisera against the N-terminal sequence to PBAN and each of the three PGNs from the Hez-PBAN prohormone were developed, and their specificity determined. In all cases, each antiserum stains the same three groups of subesophageal ganglion ventral midline neurons—the mandibular, maxillary and labial neurons—in both adult females and males. These results were confirmed using matrix assisted laser desorption/ionization mass spectrometry (MALDI MS) of individual subesophageal ganglion neuronal clusters. Using mass spectrometry, the amidated PGN-24 was not detected but an N-terminally extended form is observed that is two amino acids longer. Other peptides resulting from the processing of the Hez-PBAN prohormone were detected. Using both the specific antisera and the cellular profiling abilities of MALDI MS, the roles of individual members of the Hez-PBAN prohormone derived peptides can now be explored.