{"paper":{"title":"Non-monotonic variation with salt concentration of the second virial coefficient in protein solutions","license":"","headline":"Discrete charges on a protein surface produce a non-monotonic second virial coefficient that first falls, then rises, then falls again with added salt.","cross_cats":["cond-mat.stat-mech","q-bio"],"primary_cat":"cond-mat.soft","authors_text":"A.A. Louis, E. Allahyarov, H. L\\\"owen, J.P. Hansen","submitted_at":"2002-05-27T11:05:20Z","abstract_excerpt":"The osmotic virial coefficient $B_2$ of globular protein solutions is calculated as a function of added salt concentration at fixed pH by computer simulations of the ``primitive model''. The salt and counter-ions as well as a discrete charge pattern on the protein surface are explicitly incorporated. For parameters roughly corresponding to lysozyme, we find that $B_2$ first decreases with added salt concentration up to a threshold concentration, then increases to a maximum, and then decreases again upon further raising the ionic strength. Our studies demonstrate that the existence of a discret"},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"For parameters roughly corresponding to lysozyme, B2 first decreases with added salt up to a threshold concentration, then increases to a maximum, and then decreases again upon further raising the ionic strength.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"The primitive-model representation with a fixed discrete charge pattern on a spherical protein of lysozyme size and charge density is sufficient to capture the dominant physics governing B2 at the salt concentrations examined.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Primitive-model simulations with discrete protein charges produce a non-monotonic B2 versus added salt that DLVO theory misses.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"Discrete charges on a protein surface produce a non-monotonic second virial coefficient that first falls, then rises, then falls again with added salt.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"5b0f518ddbab7e98b194fc0ba0f597cdba2de654fd1532bce19e0fe194392716"},"source":{"id":"cond-mat/0205551","kind":"arxiv","version":1},"verdict":{"id":"25bd1792-4f90-492d-a483-c0324d86d689","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-14T20:56:47.842422Z","strongest_claim":"For parameters roughly corresponding to lysozyme, B2 first decreases with added salt up to a threshold concentration, then increases to a maximum, and then decreases again upon further raising the ionic strength.","one_line_summary":"Primitive-model simulations with discrete protein charges produce a non-monotonic B2 versus added salt that DLVO theory misses.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"The primitive-model representation with a fixed discrete charge pattern on a spherical protein of lysozyme size and charge density is sufficient to capture the dominant physics governing B2 at the salt concentrations examined.","pith_extraction_headline":"Discrete charges on a protein surface produce a non-monotonic second virial coefficient that first falls, then rises, then falls again with added salt."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/cond-mat/0205551/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":1,"snapshot_sha256":"d1ab90341a405a955ca32fa9a7c8a55315ca3dae2711cf32540a806f61963f44"},"author_claims":{"count":1,"strong_count":1,"snapshot_sha256":"5e3b23b793a24ad44d50f012bed3c12f7c9e9c566d826ad85b79440943422c6c"},"builder_version":"pith-number-builder-2026-05-17-v1"}