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Differentiation of three pairs of positional isomers of hybrid peptides with repeats of phenylalanine-beta3-h-valine/beta3-valine-phenylalanine by electrospray ionization tandem mass spectrometry.
Rapid Commun Mass Spectrom. 2007; 21(8):1401-8.RC

Abstract

Electrospray ionization ion trap mass spectrometry has been used to distinguish three pairs of positional isomers of a new series of N-blocked hybrid peptides derived from repeats of phenylalanine(D)-beta3-h-valine/beta3-h-valine-phenylalanine(D) (FbetaV/betaVF) non-natural amino acids. MSn of protonated isomeric peptides produces characteristic fragmentation involving the peptide backbone, the Boc group and the side chain. FbetaV-peptides can be distinguished from betaVF-peptides by the loss of R-OH from [M+H-Boc+H]+, which is either of relatively low abundance or totally absent for the latter peptides. In contrast, betaVF-peptides show abundant Mannich base characteristic ions by the elimination of ammonia, and imine due to a retro-Mannich cleavage. This fragmentation is absent for FbetaV-peptides. When beta-valine is at the C-terminus, abundant b+(n-1) ions are produced. This is ascribed to the probable formation of a stable diketopiperazine structure, and this has been supported by the loss of H2O and CO in the CID spectra of b+(n-1) ions. The hybrid dipeptide acids have also been distinguished in negative ion mass spectrometry.

Authors+Show Affiliations

National Centre for Mass Spectrometry, Indian Institute of Chemical Technology, Hyderabad 500 007, India.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

17370244

Citation

Ramesh, V, et al. "Differentiation of Three Pairs of Positional Isomers of Hybrid Peptides With Repeats of Phenylalanine-beta3-h-valine/beta3-valine-phenylalanine By Electrospray Ionization Tandem Mass Spectrometry." Rapid Communications in Mass Spectrometry : RCM, vol. 21, no. 8, 2007, pp. 1401-8.
Ramesh V, Nagi Reddy P, Srinivas R, et al. Differentiation of three pairs of positional isomers of hybrid peptides with repeats of phenylalanine-beta3-h-valine/beta3-valine-phenylalanine by electrospray ionization tandem mass spectrometry. Rapid Commun Mass Spectrom. 2007;21(8):1401-8.
Ramesh, V., Nagi Reddy, P., Srinivas, R., Srinivasulu, G., & Kunwar, A. C. (2007). Differentiation of three pairs of positional isomers of hybrid peptides with repeats of phenylalanine-beta3-h-valine/beta3-valine-phenylalanine by electrospray ionization tandem mass spectrometry. Rapid Communications in Mass Spectrometry : RCM, 21(8), 1401-8.
Ramesh V, et al. Differentiation of Three Pairs of Positional Isomers of Hybrid Peptides With Repeats of Phenylalanine-beta3-h-valine/beta3-valine-phenylalanine By Electrospray Ionization Tandem Mass Spectrometry. Rapid Commun Mass Spectrom. 2007;21(8):1401-8. PubMed PMID: 17370244.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Differentiation of three pairs of positional isomers of hybrid peptides with repeats of phenylalanine-beta3-h-valine/beta3-valine-phenylalanine by electrospray ionization tandem mass spectrometry. AU - Ramesh,V, AU - Nagi Reddy,P, AU - Srinivas,R, AU - Srinivasulu,G, AU - Kunwar,A C, PY - 2007/3/21/pubmed PY - 2007/5/30/medline PY - 2007/3/21/entrez SP - 1401 EP - 8 JF - Rapid communications in mass spectrometry : RCM JO - Rapid Commun Mass Spectrom VL - 21 IS - 8 N2 - Electrospray ionization ion trap mass spectrometry has been used to distinguish three pairs of positional isomers of a new series of N-blocked hybrid peptides derived from repeats of phenylalanine(D)-beta3-h-valine/beta3-h-valine-phenylalanine(D) (FbetaV/betaVF) non-natural amino acids. MSn of protonated isomeric peptides produces characteristic fragmentation involving the peptide backbone, the Boc group and the side chain. FbetaV-peptides can be distinguished from betaVF-peptides by the loss of R-OH from [M+H-Boc+H]+, which is either of relatively low abundance or totally absent for the latter peptides. In contrast, betaVF-peptides show abundant Mannich base characteristic ions by the elimination of ammonia, and imine due to a retro-Mannich cleavage. This fragmentation is absent for FbetaV-peptides. When beta-valine is at the C-terminus, abundant b+(n-1) ions are produced. This is ascribed to the probable formation of a stable diketopiperazine structure, and this has been supported by the loss of H2O and CO in the CID spectra of b+(n-1) ions. The hybrid dipeptide acids have also been distinguished in negative ion mass spectrometry. SN - 0951-4198 UR - https://www.unboundmedicine.com/medline/citation/17370244/Differentiation_of_three_pairs_of_positional_isomers_of_hybrid_peptides_with_repeats_of_phenylalanine_beta3_h_valine/beta3_valine_phenylalanine_by_electrospray_ionization_tandem_mass_spectrometry_ L2 - https://doi.org/10.1002/rcm.2975 DB - PRIME DP - Unbound Medicine ER -