Accounting for Digestion Enzyme Bias in Casanovo

peer-reviewed · Journal of Proteome Research · 2024

peer-reviewed · Journal of Proteome Research · 2024. Carlo F. Melendez et al. A key parameter of any bottom-up proteomics mass spectrometry experiment is the identity of the enzyme that…
Date 2024-09-04
Type peer-reviewed
Venue Journal of Proteome Research
Publisher ACS
Contribution algorithm
DOI 10.1021/acs.jproteome.4c00422
Citations (OpenAlex) 9
Venue 2-year citedness 3.48

Abstract

A key parameter of any bottom-up proteomics mass spectrometry experiment is the identity of the enzyme that is used to digest proteins in the sample into peptides. The Casanovo de novo sequencing model was trained using data that was generated with trypsin digestion; consequently, the model prefers to predict peptides that end with the amino acids “K” or “R”. This bias is desirable when Casanovo is used to analyze data that was also generated using trypsin but can be problematic if the data was generated using some other digestion enzyme. In this work, we modify Casanovo to take as input the identity of the digestion enzyme alongside each observed spectrum. We then train Casanovo with data generated by using several different enzymes, and we demonstrate that the resulting model successfully learns to capture enzyme-specific behavior. However, we find, surprisingly, that this new model does not yield a significant improvement in sequencing accuracy relative to a model trained without enzyme information but using the same training set. This observation may have important implications for future attempts to make use of experimental metadata in de novo sequencing models.

Authors

  1. Carlo F. Melendez · University of Washington
  2. Justin Sanders · University of Washington
  3. Melih Yilmaz · University of Washington
  4. Wout Bittremieux · Indiana University, University of Antwerp, University of California San Diego
  5. William E. Fondrie · Talus Bioscience
  6. Sewoong Oh · University of Washington
  7. William Stafford Noble · University of Washington

Methods and tools

Cites (6)

Cited by (6)

Seen in the charts

Back to the full map

Back to top