Zero-shot de novo peptide sequencing with open posttranslational modification discovery (nature.com)

• RNovA detects PTMs without retraining or candidate list
• Validated kynurenine modification in RA patient samples
• Discovered unannotated glutamic acid modification in bacterial strain

"Researchers present RNovA, a transformer-based de novo peptide sequencing algorithm that can discover posttranslational modifications (PTMs) without retraining or a predefined modification list. The model uses rotary positional embeddings and a reinforcement-learning decision framework. It identified kynurenine-modified peptides in clinical rheumatoid arthritis samples and an unannotated glutamic acid modification in a bacterial strain lacking a reference proteome. Code and data are publicly available."