{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"afe2121d06eb9bc11f0e84a936acad30f93a859a7a3dece44b12e30720c5846e","created":"2026-10-03T07:17:57Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"43c9b1bd33b0e39fac73e0842cff2687f012412078046d8499d4ebf0b9b30f66","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"value","assisted_by":[],"external_id":"bio.protein-folding.landscape-roughness","kind":"well-posed","literature_status":"open","n":"1","parents":[],"plain":"Energy landscape theory says a protein folds reliably only if the pull toward its native shape beats the roughness of its energy surface, meaning the many traps a chain can fall into. The roughness has been estimated at a few times the thermal energy, but the ratio of two temperatures that decides foldability has not been measured for a natural protein.","posed_since":"1987","precise":"In the random-energy model of folding (Bryngelson and Wolynes), foldability requires $T_f/T_g > 1$, where $T_f$ is the folding temperature and $T_g = dE / \\sqrt{2 k_B S_0}$ the glass temperature set by the energy spread dE of non-native states and their configurational entropy $S_0$; theoretical estimates for small natural proteins are of order 1.5 to 2 (approximate). Determine both dE and S_0 for the same natural protein from experiment (roughness estimates of approximately $4 \\text{ to } 5\\,k_B T$ exist; Milanesi and co-workers, 2012), and compute $T_f/T_g$ with error bars.","problem_ref":null,"references":"","settled_by":"Temperature-dependent measurement of configurational diffusion or transition-path dynamics on one protein, analyzed with the random-energy model to yield dE, $S_0$ and $T_f/T_g$.","status_note":"","title":"Measure the folding-to-glass temperature ratio of a real protein","topic_ref":"d70805bb63f25bf8902aa9ee3d70d8c036572d9638addfbea7d1b841f5ab7b17"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"b22a93f336dcda65d87bb7a6eaa6b8ecd5e328419c06d0ad62ba8a670757215f","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"fdcc1604943a12132ebceac4c8ce7d6eda9ef6f09cb99127d5834150a73db417","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"OyJ2dxn8WauuArIP_kCui58Vx8eVtNKpKHeMwBLtZsjAANRkNV9P6-YqwNdvuReohqxvkW5Yb1ufHO9UX8CYBg"},"schema":"pubphys.envelope/1"},"record_hash":"b22a93f336dcda65d87bb7a6eaa6b8ecd5e328419c06d0ad62ba8a670757215f","leaf_index":830}