A systematic N-terminal peptide quantitative labeling strategy for differential proteomic analysis.

Area of Science:

• Proteomics
• Biomarker Discovery
• Analytical Chemistry

Background:

• Differential proteomic analysis is crucial for identifying disease biomarkers.
• Existing methods can be limited in accuracy and efficiency.
• A systematic approach is needed for complex biological samples.

Purpose of the Study:

• To develop a new systematic strategy for differential proteomic analysis.
• To improve the accuracy and efficiency of quantitative proteomic studies.
• To facilitate the discovery of potential biomarkers in clinical and biological samples.

Main Methods:

• Stable isotope-coded N-terminal acetyl labeling for guanidinated peptides.
• Liquid Chromatography-Tandem Mass Spectrometry (LTQ-FT MS) for data acquisition.
• An in-house graphic user interface program "MS-based acetyl quantification" for automated data processing.

Main Results:

• The method demonstrated high effectiveness with a linear dynamic range from 0.1 to 10 (R(2) >0.999) and sensitivity down to 25 fmol.
• Statistical analysis of plasma samples showed a 99% confidence interval for quantitative ratios.
• Pilot study on cerebrospinal fluid identified 33 dysregulated proteins, showcasing method's practicality.

Conclusions:

• The developed strategy is a promising alternative for differential proteomic analysis.
• It enables efficient exploration of potential biomarkers in complex clinical and biological samples.
• Confirms utility in analyzing plasma proteins and cerebrospinal fluid.