- arXiv: bulk on S3 (https://info.arxiv.org/help/bulk_data_s3.html)
- PubMed Central Open Access: AWS Open Data (s3://pmc-oa-opendata).
- bioRxiv / medRxiv: their monthly S3 dumps
- OpenAlex: for citations, metadata, abstracts (https://developers.openalex.org/download/download-to-machine)
- AlphaFold — structures (https://alphafold.ebi.ac.uk/download)
Thanks for the question.