title: Determination of disulfide bridges in natural and recombinant insect defensin A.
abstract: The primary-structure comparison of natural insect defensin A from Phormia terranovae and recombinant insect defensin A from Saccharomyces cerevisiae has been accomplished using a combination of Edman degradation and liquid secondary ion mass spectrometry. The natural and recombinant proteins have the same primary structure with identical disulfide-bond designations (formula; see text) as determined from the peptides obtained after thermolysin digestion. The combined use of Edman degradation and mass spectometry allowed the disulfide-bridge structure to be determined with a total of only 40 micrograms (9.9 nmol) natural peptide. Mass spectrometry provides a rapid means of disulfide-bridge verification, requiring not more than 20 micrograms recombinant insect defensin A, which is compatible with use in batch analysis.
authors.affiliation: Transgène S. A., Strasbourg, France.
authors.forename: P
authors.initials: P
authors.lastname: Lepage
authors.forename: F
authors.initials: F
authors.lastname: Bitsch
authors.forename: D
authors.initials: D
authors.lastname: Roecklin
authors.forename: E
authors.initials: E
authors.lastname: Keppi
authors.forename: J L
authors.initials: JL
authors.lastname: Dimarcq
authors.forename: J M
authors.initials: JM
authors.lastname: Reichhart
authors.forename: J A
authors.initials: JA
authors.lastname: Hoffmann
authors.forename: C
authors.initials: C
authors.lastname: Roitsch
authors.forename: A
authors.initials: A
authors.lastname: Van Dorseelaer
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001798:Blood Proteins / Q000737:chemistry*; D023082:Defensins; D004175:Diptera; D004220:Disulfides; D006458:Hemolymph / Q000737:chemistry*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000737:chemistry
chemical_list: D001798:Blood Proteins; D023082:Defensins; D004220:Disulfides; D011994:Recombinant Proteins