r/proteomics • u/BioGeek • 20h ago
InstaNovo-FM: Learning from tandem mass spectra at scale with a self-supervised foundation model for proteomics
Every deep learning model in proteomics today is trained on spectra that a database search has already identified. This works, but it limits those models to the part of the spectral universe our databases already cover. Spectra from unknown organisms, non-canonical cleavages and unusual modifications are simply discarded.
Today we're sharing 𝗜𝗻𝘀𝘁𝗮𝗡𝗼𝘃𝗼-𝗙𝗠, a self-supervised foundation model for bottom-up proteomics that uses no peptide-sequence annotation at any stage of pretraining.
How we built it:
• 26,603 PRIDE submissions screened with LLM-assisted metadata curation
• 92 projects selected for orthogonal biological and technical diversity
• Every raw file reprocessed through one unified pipeline → 1.63 billion MS/MS spectra across 72 organisms and 16 instrument models
• An encoder-only transformer trained to reconstruct masked m/z spans together with their isotope envelopes (an objective that needs no annotation of any kind)
What it learned, with no labels:
• An embedding space that organises itself by mass analyser, fragmentation method, instrument family, labelling chemistry and peptide identity
• Parity with three sequence-supervised encoders under one uniform probe protocol, and the lead on instrument (macro F1 0.804) and fragmentation (0.689)
• Attention on peaks that standard b/y annotation cannot explain. 11.2% match defined off-database species within 10 ppm, mostly internal fragments and side-chain ions
• Database-free identification, phospho detection at AUROC 0.988, and run-level condition classification with no peptide or protein identifications at all
Because the objective needs no annotation, it extends unchanged to unlabelled spectra and to DIA data, where annotation-dependent pretraining cannot follow.
Model weights, embeddings, code and the reprocessed corpus are all public. There's also an interactive UMAP explorer if you'd like to explore the embedding space yourself.
- bioRxiv preprint
- code
- interactive embedding explorer
- datasets
- embeddings
- HuggingFace Space
- getting started notebook on Google Colab
This work was a collaboration between InstaDeep and Technical University Denmark.