title: Disulfide structure of the pheromone binding protein from the silkworm moth, Bombyx mori.
abstract: Disulfide bond formation is the only known posttranslational modification of insect pheromone binding proteins (PBPs). In the PBPs from moths (Lepidoptera), six cysteine residues are highly conserved at positions 19, 50, 54, 97, 108 and 117, but to date nothing is known about their respective linkage or redox status. We used a multiple approach of enzymatic digestion, chemical cleavage, partial reduction with Tris-(2-carboxyethyl)phosphine, followed by digestion with endoproteinase Lys-C to determine the disulfide connectivity in the PBP from Bombyx mori (BmPBP). Identification of the reaction products by on-line liquid chromatography-electrospray ionization mass spectrometry (LC/ESI-MS) and protein sequencing supported the assignment of disulfide bridges at Cys-19-Cys-54, Cys-50-Cys-108 and Cys-97-Cys-117. The disulfide linkages were identical in the protein obtained by periplasmic expression in Escherichia coli and in the native BmPBP.
authors.affiliation: Laboratory of Chemical Prospecting, National Institute of Sericultural and Entomological Science, 1-2 Ohwashi, Tsukuba, Japan. leal@nises.affrc.go.jp
authors.forename: W S
authors.initials: WS
authors.lastname: Leal
authors.forename: L
authors.initials: L
authors.lastname: Nikonova
authors.forename: G
authors.initials: G
authors.lastname: Peng
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D012831:Bombyx / Q000737:chemistry*; D002352:Carrier Proteins / Q000737:chemistry*; D002918:Chymotrypsin / Q000494:pharmacology; D003488:Cyanogen Bromide / Q000494:pharmacology; D004220:Disulfides / Q000737:chemistry*; D007202:Indicators and Reagents / Q000494:pharmacology; D007301:Insect Hormones / Q000737:chemistry*; D019476:Insect Proteins / Q000737:chemistry*; D036341:Intercellular Signaling Peptides and Proteins; D013058:Mass Spectrometry; D008666:Metalloendopeptidases / Q000494:pharmacology; D008969:Molecular Sequence Data; D010720:Phosphines / Q000494:pharmacology; D011994:Recombinant Proteins / Q000737:chemistry; D017386:Sequence Homology, Amino Acid
chemical_list: D002352:Carrier Proteins; D002918:Chymotrypsin; D003488:Cyanogen Bromide; D004220:Disulfides; D007202:Indicators and Reagents; D007301:Insect Hormones; D019476:Insect Proteins; D036341:Intercellular Signaling Peptides and Proteins; D008666:Metalloendopeptidases; D010720:Phosphines; D011994:Recombinant Proteins; C403094:pheromone-binding protein, Bombyx; C080938:tris(2-carboxyethyl)phosphine; C039830:peptidyl-Lys metalloendopeptidase