Protonated Dipeptide Losses from b5 and b4 Ions of Side Chain Hydroxyl Group Containing Pentapeptides

Atik, A. Emin; Yalçın, Talat

doi:10.1007/s13361-013-0694-x

Cited by 1 publication

(1 citation statement)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In our previous studies on the fragmentation reactions of E/D containing model peptides [21,22], we detected [M+H+14] + ions in the full scan mass spectra (MS). Further MS/MS experiments have revealed that the side chains of E/D residue were methylated.…”

Section: Introductionmentioning

confidence: 99%

Observation of the side chain O -methylation of glutamic acid or aspartic acid containing model peptides by electrospray ionization-mass spectrometry

Atik

Güray

Yalçın

2017

Journal of Chromatography B

Self Cite

View full text Add to dashboard Cite

O-methylation of the side chains of glutamic acid (E) and aspartic acid (D) residues is generally observed modification when an acidified methanol/water (MeOH/dHO) mixture is used as a solvent system during sample preparation for proteomic research. This chemical modification may result misidentification with endogenous protein methylation; therefore, a special care should be taken during sample handling prior to mass spectrometric analysis. In the current study, we systematically examined the extent of E/D methylation and C-terminus carboxyl group of synthetic model peptides in terms of different incubation temperatures, storage times, and added acid types as well as its percentages. To monitor these effects, C-terminus amidated and free acid forms of synthetic model peptides comprised of E or D residue(s) have been analyzed by electrospray ionization-mass spectrometry (ESI-MS). Additionally, LC-MS/MS experiments were performed to confirm the formation of methylated peptide product. The results showed that the rate of methylation was increased as the temperature increases along with prolong incubation times. Moreover, the extent of methylation was remarkably high when formic acid (FA) used as a protonation agent instead of acetic acid (AA). In addition, it was found that the degree of methylation was significantly decreased by lowering acid percentages in ESI solution. More than one acidic residue containing model peptides have been also used to explore the extent of multiple methylation reaction. Lastly, the ethanol (EtOH) and isopropanol (iPrOH) have been substituted separately with MeOH in sample preparation step to investigate the extent of esterification reaction under the same experimental conditions. However, in the positive perspective of view, this method can be used as a simple, rapid and cheap method for methylation of acidic residues under normal laboratory conditions.

show abstract

Section: Introductionmentioning

confidence: 99%

Observation of the side chain O -methylation of glutamic acid or aspartic acid containing model peptides by electrospray ionization-mass spectrometry

Atik

Güray

Yalçın

2017

Journal of Chromatography B

Self Cite

View full text Add to dashboard Cite

show abstract

Protonated Dipeptide Losses from b₅ and b₄ Ions of Side Chain Hydroxyl Group Containing Pentapeptides

Abstract: Abstract. In this study, C-terminal protonated dipeptide eliminations were reported for both b 5 and b 4 ions of side chain hydroxyl group (-OH)

Cited by 1 publication

References 37 publications

Observation of the side chain O -methylation of glutamic acid or aspartic acid containing model peptides by electrospray ionization-mass spectrometry

Observation of the side chain O -methylation of glutamic acid or aspartic acid containing model peptides by electrospray ionization-mass spectrometry

Contact Info

Product

Resources

About