The solid state oxidation of methionine containing peptide: a preliminary study using time of flight secondary ion
1Department of Chemistry, SUNY at Buffalo, New York 14260-3000, USA.
Purpose:
A surface sensitive mass spectrometric technique: Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS) was introduced to study the solid state instability of a methionine containing peptide caused by the oxidation of the methionine residue.
Methods:
The oxidation of a neuropeptide Methinonine-Enkephalin (ME) in air and under UV acceleration was studied by ToF-SIMS.
Results:
The apparent oxidation rate is defined by the peak ratio of oxidized molecular ion over unoxidized molecular ion. ME is oxidized at a faster rate to its sulfoxide derivative in the UV accelerated oxidation environment than in lab air. The calibration curve for evaluating the ionization probability ratio of the oxidized deprotonated molecular ion divided by the unoxidized deprotonated molecular ion was obtained. This could be used to extract the real oxidation rate of ME in the solid state.
Conclusions:
The preliminary results showed that ToF-SIMS with simple sample handling, fast data acquisition, together with excellent surface sensitivity and detection limit could be an applicable and convenient tool to study peptide reactions in the solid state such as oxidation and deamidation process.
More Related Videos
07:38Enabling Real-Time Compensation in Fast Photochemical Oxidations of Proteins for the Determination of Protein Topography Changes
Published on: September 1, 2020
09:40A Mass Spectrometry-Based Proteomics Approach for Global and High-Confidence Protein R-Methylation Analysis
Published on: April 28, 2022
Related Concept Videos
Chemical Ionization (CI) Mass Spectrometry
Electrospray Ionization (ESI) Mass Spectrometry
ESI utilizes electrical energy to transfer ions from the liquid phase of the sample into the...
Mass Spectrometry of Amines
MALDI-TOF Mass Spectrometry
Peptide Identification Using Tandem Mass Spectrometry
This technique helps gather information regarding the protein from which the peptide was obtained and to study the peptides’ amino acid sequence. Identifying peptides from a complex mixture is an important component of the growing field of...
Mass Spectrum: Interpretation
