A look at the face of the molten globule: Structural model of the <scp> <i>Helicobacter pylori</i> </scp> apoflavodoxin ensemble at acidic <scp>pH</scp>

Galano-Frutos, Juan José (Universidad de Zaragoza) ; Torreblanca, Renzo ; García-Cebollada, Helena (Universidad de Zaragoza) ; Sancho, Javier (Universidad de Zaragoza)

Resumen: Molten globule (MG) is the name given to acompact, non-native conformation ofproteins that has stimulated the imagination and work in the protein folding fieldfor more than 40 years. The MG has been proposed to play a central role in thefolding reaction and in important cell functions, and to be related to the onset ofmisfolding diseases. Due to its inherent intractability to high-resolution studies,atomistic structural models have not yet been obtained. We present here an inte-grative atomistic model of the MG formedat acidic pH by the apoflavodoxin fromthe human pathogenHelicobacter pylori. This MG has been previously shown toexhibit the archetypical expansion, spectroscopic and thermodynamic features of amolten conformation. To obtain the model, we have analyzed the stability of wild-type and 55 apoflavodoxin mutants to derive experimental equilibriumΦvaluesthat have been used in biased molecular dynamics simulations to convert thenative conformation into an MG ensemble. The ensemble has been refined toreproduce the experimental hydrodynamic radius and circular dichroism(CD) spectrum. The refined ensemble, deposited in PDB-Dev, successfully explainsthe characteristic1H-nuclear magnetic resonance (NMR) and near-UV CD spectralfeatures of the MG as well as its solvent-accessible surface area (SASA) changeupon unfolding. This integrative model of an MG will help to understand the ener-getics and roles of these elusive conformationsinproteinfoldingandmisfolding.Interestingly, the apoflavodoxin MG isstructurally unrelated to previouslydescribed partly unfolded conformations ofthis protein, exemplifying that equilib-rium MGs need not to reflect the properties of kinetic intermediates

Idioma: Inglés

DOI: 10.1002/pro.4445

Año: 2022

Publicado en: Protein science 31, 11 (2022), e4445 [22 pp.]
ISSN: 0961-8368

Factor impacto JCR: 8.0 (2022)

Categ. JCR: BIOCHEMISTRY & MOLECULAR BIOLOGY rank: 36 / 285 = 0.126 (2022) - Q1 - T1

Factor impacto CITESCORE: 10.8 - Biochemistry, Genetics and Molecular Biology (Q1)

Factor impacto SCIMAGO: 4.007 - Biochemistry (Q1) - Molecular Biology (Q1) - Medicine (miscellaneous) (Q1)

Financiación: info:eu-repo/grantAgreement/ES/DGA/E45-20R
Financiación: info:eu-repo/grantAgreement/ES/MICINN/PDC2021-121341-I00
Financiación: info:eu-repo/grantAgreement/ES/MICINN/PID2019-107293GB-I00

Tipo y forma: Article (Published version)

Área (Departamento): Área Bioquímica y Biolog.Mole. (Dpto. Bioq.Biolog.Mol. Celular)