title: Matrix-assisted laser desorption/ionization-post source decay fragmentation of cystine- containing amphibian peptides with novel cysteine tags.
abstract: Long disulphide-containing peptides brevinins 1E and 2Ec from the skin secretion of the frog Rana ridibunda were reduced and alkylated with ten novel and three known derivatizing agents. Nine of novel reagents are maleimide derivatives. The peptides were also reduced with DTT directly onto the MALDI target without alkylation. Modified samples were subjected to MALDI-PSD study. Procedures, fragmentation patterns, fragment ion signal abundances and sequence coverage for two peptides modified with thirteen tags (or on-plate reduced) are described. The fast on-plate procedure for reduction/alkylation was applied to Rana ridibunda crude secretion, providing intensive signals of derivatized peptides. The corresponding ions may be used for the MS/MS sequencing procedure.
authors.affiliation: Moscow State University, Russian Federation.
authors.forename: Egor A
authors.initials: EA
authors.lastname: Vorontsov
authors.forename: Tatyana Yu
authors.initials: TY
authors.lastname: Samgina
authors.forename: Vladimir A
authors.initials: VA
authors.lastname: Gorshkov
authors.forename: Nikita B
authors.initials: NB
authors.lastname: Poljakov
authors.forename: Ilya E
authors.initials: IE
authors.lastname: Nifant'ev
authors.forename: Albert T
authors.initials: AT
authors.lastname: Lebedev
mesh_terms: D000595:Amino Acid Sequence; D029845:Amphibian Proteins / Q000737:chemistry*; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry*; D003553:Cystine / Q000737:chemistry*; D004220:Disulfides / Q000737:chemistry; D005260:Female; D008297:Male; D015336:Molecular Probe Techniques; D008969:Molecular Sequence Data; D011895:Rana ridibunda; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D029845:Amphibian Proteins; D023181:Antimicrobial Cationic Peptides; D004220:Disulfides; C078413:brevinin-1 protein, Rana; C078414:brevinin-2, Rana; D003553:Cystine