Host-defence skin peptides of the Australian Common Froglet Crinia signifera: sequence determination using positive and negative ion electrospray mass spectra.
The amino acid sequences of seven signiferin peptides are provided by consideration of tandem mass spectrometric (MS/MS) data for the respective MH+ and [M--H]- precursor ions. These methods do not differentiate between isomeric residues Leu and Ile; these were identified using the Edman degradation technique. The sequence of signiferin 1, a new smooth muscle contracting neuropeptide (RLCIPYIIPC-OH) containing a disulfide bridge, is best determined using the collision-induced dissociation (CID) spectrum of the [M--H]- anion. The initial fragmentation of this system involves loss of H2S2, which furnishes an open-chain system that is readily sequenced using the alpha and beta backbone cleavage anions.
Maselli
Vita M
VM
Department of Chemistry, The University of Adelaide, South Australia, 5005.
Brinkworth
Craig S
CS
Bowie
John H
JH
Tyler
Michael J
MJ
D000595:Amino Acid Sequence; D029845:Amphibian Proteins / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D007109:Immunity; D007477:Ions; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D010455:Peptides / Q000032:analysis* / Q000737:chemistry* / Q000378:metabolism; D011898:Ranidae / Q000378:metabolism*; D020539:Sequence Analysis, Protein / Q000379:methods*; D012867:Skin / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D029845:Amphibian Proteins; D007477:Ions; D009479:Neuropeptides; D010455:Peptides; C000593716:signiferin 1 peptide, Crinia signifera