title: Chromophore effect in photodissociation at 266 nm of protonated peptides generated by matrix-assisted laser desorption ionization (MALDI).
abstract: Chromophore effect in the photodissociation of protonated peptides at 266 nm was investigated using synthetic peptides with the sequence RGGXGGGGGR where X was a phenylalanyl(F), tyrosyl(Y), cysteinyl(C), glycyl(G), seryl(S), or histidyl(H) residue. The peptides with an F or Y residue dissociated efficiently. Fragment ions due to cleavages at either end of the chromophore were especially prominent just as for the peptide with a tryptophanyl residue reported previously.1Photodissociation was observed even for the peptides without any noticeable chromophore at 266 nm. Here, dissociation at all the peptide bonds was almost equally prominent. Photodissociation of the protonated angiotensin I was investigated using the spectral correlation rules observed in the model systems. Role of the chromophores and the plausible mechanisms involved are discussed.
authors.affiliation: National Creative Research Initiative Center for Control of Reaction Dynamics and School of Chemistry, Seoul National University, Seoul 151-742, Korea.
authors.forename: Joo Yeon
authors.initials: JY
authors.lastname: Oh
authors.forename: Jeong Hee
authors.initials: JH
authors.lastname: Moon
authors.forename: Myung Soo
authors.initials: MS
authors.lastname: Kim
mesh_terms: D000595:Amino Acid Sequence; D000803:Angiotensin I / Q000737:chemistry; D008027:Light; D008956:Models, Chemical; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry*; D010782:Photolysis / Q000528:radiation effects*; D011522:Protons; D020539:Sequence Analysis, Protein; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation / Q000379:methods*
chemical_list: D010455:Peptides; D011522:Protons; D000803:Angiotensin I