A multi-purpose, regenerable, proteome-scale, human phosphoserine resource for phosphoproteomics

Area of Science:

• Proteomics
• Cellular Signaling
• Biochemistry

Background:

• Phosphoproteomics is crucial for understanding cellular signaling.
• The field requires cost-effective, reproducible, and diverse phosphopeptides with known phosphorylation sites.

Purpose of the Study:

• To develop a proteome-scale library of human phosphoserine phosphopeptides with precisely defined phosphorylation sites.
• To provide a resource for validating phosphopeptide standards and optimizing phosphorylation site localization algorithms.

Main Methods:

• Creation of Iterative Synthetically Phosphorylated Isomers (iSPI) library.
• Development of AScorePro, an enhanced AScore algorithm for higher energy fragmentation spectra.
• Introduction of the FLR viewer, a web tool for phosphorylation site localization.

Main Results:

• iSPI offers an inexpensive, regenerable, and diverse collection of phosphopeptides.
• The library serves as a standard for phosphopeptide analysis and a benchmark for data analysis pipelines.
• AScorePro and FLR viewer facilitate improved phosphorylation site localization.

Conclusions:

• iSPI is a valuable, multi-purpose resource for the phosphoproteomics community.
• The developed tools enhance the accuracy and efficiency of phosphoproteomic data analysis.
• This work advances the study of cellular signaling through improved phosphopeptide characterization.