biostudies-literatureRider RLWelch FoundationNational Institutes of HealthNIGMS NIH HHS3028-3036https://www.ebi.ac.uk/biostudies/studies/S-EPMC11622221biostudies-literatureUnknown35(12)Collision-induced unfolding (CIU) has provided new levels of understanding of the stabilities and structure(s) for gas phase protein and protein complex ions formed by electrospray ionization (ESI). Variable-temperature (vT-ESI) data provide complementary information about temperature-induced folding/unfolding (TIU) reactions of solution phase ions. Results obtained by using CIU and TIU provide complementary information about stabilities of gas phase versus solution phase ions. Such comparisons may provide the most direct experimental approach to answer a long-standing question from Fred McLafferty: "For how long, under what conditions, and to what extent, can solution structure be retained without solvent?" Answers to this question require greater understanding of the (i) structure(s), stJournal of the American Society for Mass SpectrometryStructure and Stabilities of Solution and Gas Phase Protein Complexes.PMC11622221A-2162-20230405RM1GM149374RM1 GM149374Rider RLLantz CFan LRussell DHfalseStructure and Stabilities of Solution and Gas Phase Protein Complexes.Collision-induced unfolding (CIU) has provided new levels of understanding of the stabilities and structure(s) for gas phase protein and protein complex ions formed by electrospray ionization (ESI). Variable-temperature (vT-ESI) data provide complementary information about temperature-induced folding/unfolding (TIU) reactions of solution phase ions. Results obtained by using CIU and TIU provide complementary information about stabilities of gas phase versus solution phase ions. Such comparisons may provide the most direct experimental approach to answer a long-standing question from Fred McLafferty: "For how long, under what conditions, and to what extent, can solution structure be retained without solvent?" Answers to this question require greater understanding of the (i) structure(s), st2024-01-01T00:00:00Z2024 Dec2025-04-21T21:56:38.396Z2025-04-21T21:56:38.396ZS-EPMC116222213956963210.1021/jasms.4c00306