Disulfide connectivity and reduction in pheromone-binding proteins of the gypsy moth, Lymantria dispar.
Males of the gypsy moth, Lymantria dispar, are attracted by a pheromone released by females. Pheromones are detected by olfactory neurons housed in specialized sensory hairs located on the antennae of the male moth. Once pheromone molecules enter the sensilla lymph, a highly abundant pheromone-binding protein (PBP) transports the molecule to the sensory neuron. The PBPs are members of the insect odorant-binding protein family, with six conserved cysteine residues. In this study, the disulfide bond connectivities of the pheromone-binding proteins PBP1 and PBP2 from the gypsy moth were found to be cysteines 19-54, 50-109, and 97-118 for PBP1, and cysteines 19-54, 50-110, and 97-119 for PBP2, as determined by cyanylation reactions and cyanogen bromide chemical cleavage. We have discovered that the second disulfide linkage is the most easily reduced of the three, and this same linkage is missing among four cysteine-containing insect odorant-binding proteins (OBPs). We are the first to identify the unique steric and electronic properties of this second disulfide linkage.
Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada.
Nicolette S
NS
Honson
Erika
E
Plettner
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D004220:Disulfides / Q000378:metabolism*; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009036:Moths / Q000378:metabolism*; D010084:Oxidation-Reduction; D010446:Peptide Fragments / Q000737:chemistry; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D000596:Amino Acids; D002352:Carrier Proteins; D004220:Disulfides; D019476:Insect Proteins; D010446:Peptide Fragments; D011994:Recombinant Proteins; C403713:pheromone binding protein, insect