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dc.contributor.authorEnglish, Lance R. ( Orcid Icon 0000-0002-1850-7729 )
dc.contributor.authorTischer, Alexander ( )
dc.contributor.authorDemeler, Aysha K. ( )
dc.contributor.authorDemeler, Borries ( )
dc.contributor.authorWhitten, Steven T. ( )
dc.date.accessioned2019-08-27T20:31:41Z
dc.date.available2019-08-27T20:31:41Z
dc.date.issued2018-07
dc.identifier.citationEnglish, L. R., Tischer, A., Demeler, A. K., Demeler, B., & Whitten, S. T. (2018). Sequence Reversal Prevents Chain Collapse and Yields Heat-Sensitive Intrinsic Disorder. Biophysical Journal, 115(2), pp. 328–340.en_US
dc.identifier.urihttps://digital.library.txstate.edu/handle/10877/8554
dc.description.abstractSequence patterns of charge, hydrophobicity, hydrogen bonding, and other amino acid physicochemical properties contribute to mechanisms of protein folding, but how sequence composition and patterns influence the conformational dynamics of the denatured state ensemble is not fully understood. To investigate structure-sequence relationships in the denatured state, we reversed the sequence of staphylococcal nuclease and characterized its structure, thermodynamic character, and hydrodynamic radius using circular dichroism spectroscopy, dynamic light scattering, analytical ultracentrifugation, and size-exclusion chromatography as a function of temperature. The macromolecular size of "Retro-nuclease" is highly expanded in solution with characteristics similar to biological intrinsically disordered proteins. In contradistinction to a disordered state, Retro-nuclease exhibits a broad sigmoid transition of its hydrodynamic dimensions as temperature is increased, indicating a thermodynamically controlled compaction. Counterintuitively, the magnitude of these temperature-induced hydrodynamic changes exceed that observed from thermal denaturation of folded unaltered staphylococcal nuclease. Undetectable by calorimetry and intrinsic tryptophan fluorescence, the lack of heat capacity or fluorescence changes throughout the thermal transition indicate canonical hydrophobic collapse did not drive the Retro-nuclease structural transitions. Temperature-dependent circular dichroism spectroscopy performed on Retro-nuclease and computer simulations correlate to temperature sensitivity in the intrinsic sampling of backbone conformations for polyproline II and α-helix. The experimental results indicate a role for sequence direction in mediating the collapse of the polypeptide chain, whereas the simulation trends illustrate the generality of the observed heat effects on disordered protein structure.en_US
dc.formatText
dc.format.extent15 pages
dc.format.medium1 file (.pdf)
dc.language.isoen_USen_US
dc.publisherBiophysical Society (Elsevier)en_US
dc.sourceBiophysical Journal, 2018, Vol. 115, No. 2, pp. 328–340
dc.subjectSequence composition
dc.subjectChain collapse
dc.subjectHeat-sensitive intrinsic disorder
dc.subjectProtein structures
dc.titleSequence Reversal Prevents Chain Collapse and Yields Heat-Sensitive Intrinsic Disorderen_US
txstate.documenttypeArticle
dc.description.versionThis is the accepted manuscript version of an article published in Biophysical Journal.
dc.identifier.doihttps://doi.org/10.1016/j.bpj.2018.06.006
txstate.departmentChemistry and Biochemistry


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