{"doi":"10.1002/pro.70126","title":"Crowding‐induced stabilization and destabilization in a single protein","abstract":"Abstract The protein concentration in cells can reach 300 g/L. These crowded conditions affect protein stability. Classic crowding theories predict entropically driven stabilization, which occurs via steric repulsion, but growing evidence shows a role for non‐covalent chemical interactions. To aid our understanding of physiologically relevant crowding, we used NMR‐detected 1 H‐ 2 H exchange to examine a simple, semi‐reductionist system: protein self‐crowding at the residue level using the widely studied model globular protein, GB1 (the B1 domain streptococcal protein G) at concentrations up to its solubility limit, 100 g/L. The surprising result is that self‐crowding stabilizes some residues but destabilizes others, contradicting predictions. Two other observations are also contradictory. First, temperature‐dependence data show that stabilization can arise enthalpically, not just entropically. Second, concentration‐dependence data show destabilization often increases with increasing concentration. These results show a key role for chemical interactions. More specifically, self‐crowding increases the free energy required to expose those residues that are only exposed upon complete unfolding, and stabilization of these globally unfolding residues increases with GB1 concentration, a result we attribute to repulsive chemical interactions between GB1 molecules. On the other hand, residues exposed upon local unfolding tend to be destabilized, with destabilization increasing with concentration, a result we attribute to attractive chemical interactions between GB1 molecules.","journal":"Protein Science","year":2025,"id":521016,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":5,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9548,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1391306,"name":"Tarynn D. Neal","orcid":null,"position":1,"is_corresponding":false},{"id":1391307,"name":"Hania S. Kantzer","orcid":null,"position":2,"is_corresponding":false},{"id":326172,"name":"Gary J. Pielak","orcid":"0000-0001-6307-542X","position":3,"is_corresponding":false},{"id":1390882,"name":"Jordyn M. Markle","orcid":"0000-0002-5452-0082","position":0,"is_corresponding":true}],"reference_count":61,"raw_metadata":null,"created_at":"2026-07-19T02:49:32.958846Z","pmid":"40260960","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}