tipNrich: A Tip-Based N-Terminal Proteome Enrichment Method

Anal Chem. 2021 Oct 26;93(42):14088-14098. doi: 10.1021/acs.analchem.1c01722. Epub 2021 Oct 6.

Abstract

The mass spectrometry-based analysis of protein post-translational modifications requires large amounts of sample, complicating the analysis of samples with limited amounts of proteins such as clinical biopsies. Here, we present a tip-based N-terminal analysis method, tipNrich. The entire procedure is processed in a single pipette tip to minimize sample loss, which is so highly optimized to analyze small amounts of proteins, even femtomole-scale of a single protein. With tipNrich, we investigated various single proteins purified from different organisms using a low-resolution mass spectrometer and identified several N-terminal peptides with different Nt-modifications such as ragged N-termini. Furthermore, we applied matrix-assisted laser desorption ionization time-of-flight mass spectrometry to our method for shortening the analysis time. Moreover, we showed that our method could be utilized in disease diagnosis as exemplified by the characterization of wild-type transthyretin amyloidosis patients compared to the healthy individuals based on N-terminome profiling. In summary, tipNrich will satisfy the need of identifying N-terminal peptides even with highly scarce amounts of proteins and of having faster processing time to check the quality of protein products or to characterize N-terminal proteoform-related diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Humans
  • Mass Spectrometry
  • Peptides*
  • Protein Processing, Post-Translational
  • Proteome* / metabolism

Substances

  • Peptides
  • Proteome