Related Experiment Video
Updated: Jul 31, 2025
10:05
Large-scale Top-down Proteomics Using Capillary Zone Electrophoresis Tandem Mass Spectrometry
Published on: October 24, 2018
9.5K
High sensitivity top-down proteomics captures single muscle cell heterogeneity in large proteoforms.
Jake A Melby1, Kyle A Brown1, Zachery R Gregorich2
1Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706.
Summary
Top-down proteomics reveals single muscle fiber proteoform heterogeneity. This method links sarcomeric proteoforms to distinct muscle fiber types, advancing our understanding of cellular variation.
Area of Science:
- Proteomics
- Cellular Biology
- Muscle Physiology
Background:
- Single-cell proteomics is crucial for understanding cellular heterogeneity.
- Challenges exist in analyzing complex proteoforms (e.g., from mutations, splicing, PTMs) at the single-cell level.
Purpose of the Study:
- To develop a sensitive top-down proteomics method for comprehensive single-cell proteoform analysis.
- To investigate proteomic heterogeneity in single muscle fibers (SMFs).
Main Methods:
- Developed a functionally integrated top-down proteomics approach.
- Applied the method to single muscle fibers from distinct muscle types.
- Analyzed large proteoforms (>200 kDa) and myosin heavy chain isoforms.
Main Results:
- Detected significant heterogeneity in large proteoforms within single muscle fibers.
- Observed fiber-to-fiber differences in sarcomeric proteoforms correlating with functional heterogeneity.
- Reproducibly identified multiple myosin heavy chain isoforms, enabling fiber type classification.
Conclusions:
- Single muscle cells exhibit heterogeneity in large proteoforms.
- A direct link between sarcomeric proteoforms and muscle fiber types was established.
- Top-down proteomics offers potential for elucidating cell-to-cell variation in complex biological systems.
