Top-down proteomics: applications, recent developments and perspectives

Annapurna Pamreddy,Nagender Reddy Panyala

doi:10.17145/jab.16.009

Abstract

Now-a-days, top-down proteomics (TDP) is a booming approach for the analysis of intact proteins and it is attaining significant interest in the field of protein biology. The term has emerged as an alternative to the well-established, bottom-up strategies for analysis of peptide fragments derived from either enzymatically or chemically digestion of intact proteins. TDP is applied to mass spectrometric analysis of intact large biomolecules that are constituents of protein complexes and assemblies. This article delivers an overview of the methodologies in top-down mass spectrometry, mass spectrometry instrumentation and an extensive review of applications covering the venomics, biomedical research, protein biology including the analysis of protein post-translational modifications (PTMs), protein biophysics, and protein complexes. In addition, limitations of top-down proteomics, challenges and future directions of TDP are also discussed.

Highlights

In recent years the mass spectrometry (MS) ionization techniques such as electro spray ionization (ESI) [1] and MALDI [2] have been applied for the detection of a wide variety of large biopolymers, such as proteins [3,4], lipids, and nucleic acids
This article delivers an overview of the methodologies in top-down mass spectrometry, mass spectrometry instrumentation and an extensive review of applications covering the venomics, biomedical research, protein biology including the analysis of protein post-translational modifications (PTMs), protein biophysics, and protein complexes
From the above-mentioned top-down MS applications, it is clearly noted that TD mass spectrometry is well-suited for target-compound analysis

Summary

Introduction

In recent years the mass spectrometry (MS) ionization techniques such as ESI [1] and MALDI [2] have been applied for the detection of a wide variety of large biopolymers, such as proteins [3,4], lipids, and nucleic acids. Mass spectrometry-based proteomics has been carried out in a bottom-up fashion In these BUP experiments, proteins are separated on the basis of their isoelectric point (pI) and molecular weight, respectively [7]. Top-down proteomics can eliminate these problems by the introduction of an intact protein into the mass spectrometer where both its intact and fragment ions masses are measured (Figure 1). This strategy usually covers 100% sequence coverage and full characterization of proteoforms including PTMs and sequence variations. It might be possible to see a high throughput work flow which covers intact proteins and polypeptides up to 70 kDa in near future with the combination of advanced commercial MS instrumentation and data processing [26]

Methodology

Findings

Conclusion