{"title":"Temperature-Dependent Rotation of Protonated Methyl Groups in Otherwise Deuterated Proteins Modulates DEER Distance Distributions","authors":"Thomas Schmidt, Valentyn Stadnytskyi","doi":"10.1007/s00723-024-01720-5","DOIUrl":null,"url":null,"abstract":"<div><p>Temperature-dependent DEER effects are observed as a function of methyl rotation by either leucine- or nitroxide-specific protonated methyl groups in an otherwise deuterated background. Both species induce a site-specific enhancement in the apparent <i>T</i><sub>m</sub> relaxation of the paramagnetic nitroxide label. The presence of a single protonated methyl group in close proximity (4–10 Å) to only one of the two nitroxide rotamer ensembles in AviTagged immunoglobulin-binding B domain of protein A results in a selective and substantial decrease in <i>T</i><sub>m</sub>, manifested by differential decay of the peak intensities in the bimodal <i>P(r)</i> distance distribution as a function of the total dipolar evolution time, temperature, or both. The temperature-dependent differential decay of the individual distance components was globally analyzed by fitting the DEER dipolar time traces to a three-site jump model that is defined by the activation energy of leucine- or nitroxide-specific methyl rotation. Temperature-assisted T<sub>m</sub> filtering will capture the DEER structural analysis of biomolecular systems heterogenic conformations, including complexes involving multimeric proteins.</p></div>","PeriodicalId":469,"journal":{"name":"Applied Magnetic Resonance","volume":"56 1-2","pages":"91 - 102"},"PeriodicalIF":1.1000,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11775055/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Applied Magnetic Resonance","FirstCategoryId":"101","ListUrlMain":"https://link.springer.com/article/10.1007/s00723-024-01720-5","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"PHYSICS, ATOMIC, MOLECULAR & CHEMICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Temperature-dependent DEER effects are observed as a function of methyl rotation by either leucine- or nitroxide-specific protonated methyl groups in an otherwise deuterated background. Both species induce a site-specific enhancement in the apparent Tm relaxation of the paramagnetic nitroxide label. The presence of a single protonated methyl group in close proximity (4–10 Å) to only one of the two nitroxide rotamer ensembles in AviTagged immunoglobulin-binding B domain of protein A results in a selective and substantial decrease in Tm, manifested by differential decay of the peak intensities in the bimodal P(r) distance distribution as a function of the total dipolar evolution time, temperature, or both. The temperature-dependent differential decay of the individual distance components was globally analyzed by fitting the DEER dipolar time traces to a three-site jump model that is defined by the activation energy of leucine- or nitroxide-specific methyl rotation. Temperature-assisted Tm filtering will capture the DEER structural analysis of biomolecular systems heterogenic conformations, including complexes involving multimeric proteins.
期刊介绍:
Applied Magnetic Resonance provides an international forum for the application of magnetic resonance in physics, chemistry, biology, medicine, geochemistry, ecology, engineering, and related fields.
The contents include articles with a strong emphasis on new applications, and on new experimental methods. Additional features include book reviews and Letters to the Editor.