Determination of disulfide bridges in natural and recombinant insect defensin A.
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.
Lepage
P
P
Transgène S. A., Strasbourg, France.
Bitsch
F
F
Roecklin
D
D
Keppi
E
E
Dimarcq
J L
JL
Reichhart
J M
JM
Hoffmann
J A
JA
Roitsch
C
C
Van Dorseelaer
A
A
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
D001798:Blood Proteins; D023082:Defensins; D004220:Disulfides; D011994:Recombinant Proteins