Research Topics
| A G HarrisonSummaryAffiliation: University of Toronto Country: Canada Publications
| Collaborators
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Detail Information
Publications
Cyclization of peptide b9 ionsAlex G Harrison
Department of Chemistry, University of Toronto, Toronto, ON, Canada
J Am Soc Mass Spectrom 20:2248-53. 2009..N-terminal acetylation blocks the cyclization and eliminates nondirect sequence fragment ions in the product ion mass spectra...- Fragmentation reactions of b(5) and a (5) ions containing proline--the structures of a(5) ionsAlex G Harrison
Department of Chemistry, University of Toronto, 80 St George Street, Toronto, ON, M5S 3H6, Canada
J Am Soc Mass Spectrom 23:594-601. 2012..The observation of these products provides strong experimental evidence for the cyclization/rearrangement reaction to form amides and shows that it also applies to a(5) ions... - Pathways for water loss from doubly protonated peptides containing serine or threonineAlex G Harrison
Department of Chemistry, University of Toronto, 80 St George Street, Toronto, ON, M5S 3H6, Canada
J Am Soc Mass Spectrom 23:116-23. 2012..The [MH - H(2)O](+) ion of Ala-Ala-Ser-Ala-Ala-Ala also shows elimination of CH(3)CH=NH, one Ala residue and two Ala residues... 
Scrambling of sequence information in collision-induced dissociation of peptidesAlex G Harrison
Department of Chemistry, University of Toronto, 80 St George Street, Toronto, Ontario M5S 3H6, Canada
J Am Chem Soc 128:10364-5. 2006..The latter can undergo various proton transfer reactions and opens up to form something other than the YAGFLoxa linear b5 isomer, leading to scrambling of sequence information in the CID of protonated YAGFL-NH2...- Peptide sequence scrambling through cyclization of b(5) ionsAlex G Harrison
Department of Chemistry, University of Toronto, Toronto, Canada
J Am Soc Mass Spectrom 19:1776-80. 2008..A comparison of the fragmentation of AAAYAA and Ac-AAAYAA indicates that N-acetylation eliminates the cyclization of b(5) ions and, thus, eliminates the nonsequence ions in the CID mass spectra of both b(5) and MH(+) ions... - Fragmentation reactions of some peptide b3 ions: an energy-resolved studyAlex G Harrison
Department of Chemistry, University of Toronto, Toronto, Canada
Rapid Commun Mass Spectrom 23:1298-302. 2009..The results support and expand upon the detailed mechanism of fragmentation of b3 ions proposed by Cooper et al. (J. Am. Soc. Mass Spectrom. 2006; 17: 1654)... - To b or not to b: the ongoing saga of peptide b ionsAlex G Harrison
Department of Chemistry, University of Toronto, Toronto, ON, Canada
Mass Spectrom Rev 28:640-54. 2009..The recent discovery of full cyclization of larger b ions results in challenges in peptide sequencing. This aspect is discussed in detail... - Charge-separation reactions of doubly-protonated peptides: effect of peptide chain lengthAlex G Harrison
Department of Chemistry, University of Toronto, Toronto, Ontario, Canada
J Am Soc Mass Spectrom 20:1890-5. 2009..2008, 19, 1755-1763) from a statistical analysis of a large body of doubly-protonated tryptic peptide CID mass spectra. It is shown that the b2 ion derived from doubly-protonated (Ala)5His has a protonated oxazolone structure... - Effect of the identity of Xaa on the fragmentation modes of doubly-protonated Ala-Ala-Xaa-Ala-Ala-Ala-ArgAlex G Harrison
Department of Chemistry, University of Toronto, 80 St George Street, Toronto, ON, M5S 3H6, Canada
J Am Soc Mass Spectrom 22:906-11. 2011..Proline showed a unique behavior in giving a much higher y(5)(+2)/y(5) ratio than any of the other residues studied... - Fragmentation reactions of deprotonated peptides containing proline. The proline effectAlex G Harrison
Department of Chemistry, University of Toronto, Toronto, Canada
J Mass Spectrom 40:1173-86. 2005..This proline effect is compared and contrasted with the similar proline effect observed in the fragmentation of protonated peptides containing proline... - Fragmentation of protonated oligoalanines: amide bond cleavage and beyondAlex G Harrison
Department of Chemistry, University of Toronto, 80 George Street, Toronto, Ontario M5S 3H6, Canada
J Am Soc Mass Spectrom 15:1810-9. 2004..A cyclic structure is proposed for the a(3)* ion... - Formation of iminium ions by fragmentation of a2 ionsAlex G Harrison
Department of Chemistry, University of Toronto, Toronto, Canada
Rapid Commun Mass Spectrom 18:1635-40. 2004..The experimental results are interpreted in terms of these energetics data, unimolecular rate constants calculated by using the RRKM theory, and the imine proton affinities... - Structure and fragmentation of b2 ions in peptide mass spectraA G Harrison
Department of Chemistry, University of Toronto, Ontario, Canada
J Am Soc Mass Spectrom 11:427-36. 2000..When the C-terminus residue is Val or larger, the b2-->a1 reaction cannot compete with the b2-->a2 fragmentation reaction. Some preliminary results on the fragmentation of a2 ions are reported... - Sequence-specific fragmentation of deprotonated peptides containing H or alkyl side chainsA G Harrison
Department of Chemistry, University of Toronto, Ontario, Canada
J Am Soc Mass Spectrom 12:1-13. 2001..Mechanistic aspects of the fragmentation reactions observed are discussed... - Fragmentation reactions of protonated peptides containing glutamine or glutamic acidAlex G Harrison
Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
J Mass Spectrom 38:174-87. 2003..Isotopic labelling shows extensive mixing of labile and carbon-bonded hydrogens in the formation of protonated glycinamide... - Amide bond cleavage in deprotonated tripeptides: a newly discovered pathway to "b2 ionsAlex G Harrison
Department of Chemistry, University of Toronto, Toronto, Canada
Rapid Commun Mass Spectrom 17:869-75. 2003..It is proposed that the "b(2) ions are deprotonated oxazolones... - Characterization of alpha- and gamma-glutamyl dipeptides by negative ion collision-induced dissociationAlex G Harrison
Department of Chemistry, University of Toronto, 80 St George Street, Toronto, Ontario M5S 3H6, Canada
J Mass Spectrom 39:136-44. 2004.... - Fragmentation of deprotonated N-benzoylpeptides: formation of deprotonated oxazolonesAlex G Harrison
Department of Chemistry, University of Toronto, Toronto, Ontario, Canada
J Am Soc Mass Spectrom 15:446-56. 2004.... - Energy-resolved mass spectrometry: a comparison of quadrupole cell and cone-voltage collision-induced dissociationA G Harrison
Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada
Rapid Commun Mass Spectrom 13:1663-70. 1999..The comparison has been made for the protonated peptides H-Leu-Gly-Gly-OH, H-Gly-Leu-Gly-OH, H-Gly-Gly-Leu-OH and Leu-enkephalin.. - Effect of phenylalanine on the fragmentation of deprotonated peptidesAlex G Harrison
Department of Chemistry, University of Toronto, Ontario, Canada
J Am Soc Mass Spectrom 13:1242-9. 2002..Sequence ions frequently observed are the y1 ions, "b2 ions and a3-Nt ions... - Fragmentation of protonated dipeptides containing arginine. Effect of activation methodMatthew W Forbes
Department of Chemistry, University of Toronto, Toronto, Ontario, Canada
J Am Soc Mass Spectrom 18:1959-66. 2007..Based largely on elemental compositions derived from accurate mass measurements in QqTOF studies fragmentation schemes are proposed for the MH(+), [MH - NH(3)](+), and [MH - (HN = C(NH(2))(2))](+) ions... - Experimental and theoretical investigation of the main fragmentation pathways of protonated H-Gly-Gly-Sar-OH and H-Gly-Sar-Sar-OHBela Paizs
Department of Molecular Biophysics, German Cancer Research Center, Heidelberg, Germany
J Am Soc Mass Spectrom 14:1454-69. 2003..Theoretical modeling and analysis of the main fragmentation pathways indicate that the majority of the b2 and y1 ions of protonated H-Gly-Gly-Sar-OH and the b2 ions of H-Gly-Sar-Sar-OH are formed on the b2-y1 pathway...