Dissociation of protonated peptides containing adjacent arginines.
The dissociation of protonated peptides containing adjacent arginines has been studied by electrospray ionization-tandem mass spectrometry (ESI MS/MS) and theoretical calculations. The experimental results show that singly protonated peptides cleave at the Arg-Arg amide bond and generate the y(1) ion when adjacent arginines are the C-terminal residues. The major cleavage occurs at the C-terminal amide bond and produces the b(n-1) ion when adjacent arginines are not the C-terminal residues. The diketopiperazine and oxazolone fragmentation pathways of protonated NRR (Asn-Arg-Arg) have been investigated at the B3LYP/6-31G(d) and B3LYP/6-31++G(d,p) levels of theory. The geometries and energies of transition state species and hydrogen-bonding interaction are also discussed.
Xiao
Yongsheng
Y
Department of Chemistry, Beijing Normal University, Beijing, 100875 PR China.
Zu
Lily
L
Zhang
E
E
Peng
Juan
J
Huang
Linyun
L
He
Dacheng
D
Fang
Weihai
W
D000595:Amino Acid Sequence; D001120:Arginine / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010455:Peptides / Q000737:chemistry / Q000235:genetics; D011522:Protons; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods
D010455:Peptides; D011522:Protons; D001120:Arginine