Single chain variable fragment displaying M13 phage library functionalized magnetic microsphere-based protein...

Area of Science:

• Proteomics
• Biotechnology
• Analytical Chemistry

Background:

• Human serum proteomic analysis is challenging due to the high abundance of a few proteins masking low-abundance ones.
• Existing methods for high-abundance protein depletion often face limitations in efficiency and scope.

Purpose of the Study:

• To develop and evaluate a novel magnetic microsphere-based system for efficient depletion of high-abundance proteins in human serum.
• To assess the impact of this depletion method on subsequent proteomic identification.

Main Methods:

• Covalent immobilization of M13 phage single chain variable fragment (scFv) library onto magnetic microspheres (scFv@M13@MM).
• Incubation of scFv@M13@MM with human serum, followed by sequential elution of captured proteins.
• Analysis of eluates using SDS-PAGE and 2D-strong cation exchange-RPLC-ESI-MS/MS after trypsin digestion.

Main Results:

• scFv@M13@MM treatment significantly reduced the concentration differences of proteins in human serum fractions.
• A 100% increase in identified proteins was observed in serum treated with scFv@M13@MM compared to untreated samples.
• Spectral counts of 10 major high-abundance proteins, including albumin and transferrin, were markedly decreased.

Conclusions:

• scFv@M13@MM serves as an effective protein equalizer for human serum.
• This method enhances proteomic depth by reducing the dynamic range of protein concentrations.
• The approach facilitates more comprehensive identification of low-abundance proteins in complex biological samples.