Low-molecular weight plasma proteome analysis using centrifugal ultrafiltration

Area of Science:

• Proteomics
• Biomarker Discovery
• Human Plasma Analysis

Background:

• The low-molecular weight fraction (LMF) of human plasma is a rich source of potential disease biomarkers.
• Existing methods for LMF analysis can be time-consuming and lack reproducibility.
• Standardized protocols are needed for efficient LMF profiling.

Purpose of the Study:

• To develop and validate a standardized protocol for rapid and reproducible profiling of the human plasma LMF.
• To enhance the identification of novel plasma-based biomarkers for disease detection.

Main Methods:

• Centrifugal ultrafiltration for plasma fractionation based on molecular size.
• 1D-SDS-PAGE for protein separation.
• Nano-liquid chromatography-tandem mass spectrometry (nano-LC-MS/MS) for peptide identification.

Main Results:

• Optimized centrifugal ultrafiltration achieved >95% recovery and enrichment of low-molecular-weight plasma components.
• Identification of over 260 unique peptides from 100 μL of plasma.
• Novel identification of several plasma proteins, including KIAA0649 and transmembrane adapter protein PAG, not previously reported in high-confidence datasets.

Conclusions:

• The developed protocol offers a rapid, reproducible, and efficient method for human plasma LMF profiling.
• This approach significantly expands the repertoire of identified plasma proteins, aiding in biomarker discovery.
• The method facilitates the identification of previously unreported proteins, advancing proteomic research.