On the Structural Stability and Solvent Denaturation of Proteins

Herskovits, Theodore T.; Gadegbeku, Barbara; Jaillet, Helen

doi:10.1016/s0021-9258(18)63111-4

Cited by 337 publications

(74 citation statements)

References 49 publications

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“…They concluded that the structure has six helices, five of which are located in the helical region of the polypeptide chain and the rest is located in the P-sheet region of the native state. Although the efficiency is not the same, similar effects of methanol and TFE are expected on the helix formation (Bianchi et al, 1970;Conio et al, 1970;Herskovits et al, 1970;Thomas & Dill, 1993;Shiraki et al, 1995). Comparison between the CD spectra in methanol (Fig.…”

Section: Structural Characterization Of the Helical Denatured State (H) At High Concentrations Of Methanolmentioning

confidence: 67%

“…Addition of alcohol is known to destabilize the tertiary structure of a protein (Conio et al, 1970;Herskovits et al, 1970;Fink & Painter, 1987;Nakano & Fink, 1990) and to stabilize the helical structure (Nelson & Kallenbach, 1986,1989Lehrman et al, 1990;Segawa et al, 1991;Dyson et al, 1992aDyson et al, , 1992bKippen et al, 1994;Shiraki et al, 1995;Hirota et al, 1997). In the previous study (Kamatari et al, 1996), we investigated methanol-induced conformational transitions of cytochrome c in detail, in which we found that the helical state realized at high methanol concentration has an expanded chain structure (H).…”

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confidence: 89%

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The methanol‐induced transition and the expanded helical conformation in hen lysozyme

et al. 1998

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Methanol-induced conformational transitions of hen egg white lysozyme were investigated with a combined use of farand near-UV CD and N M R spectroscopies, ANS binding and small-angle X-ray scattering. Addition of methanol induced no global change in the native conformation itself, but induced a transition from the native state to the denatured state which was highly cooperative, as shown by the coincidence of transition curves monitored by the far-and near-UV CD spectroscopy, by isodichroic points in the far-and near-UV CD spectra and by the concomitant disappearance of individual 'H N M R signals of the native state. The ANS binding experiments could detect no intermediate conformer similar to the molten globule state in the process of the methanol denaturation. However, at high concentration of methanol, e.g., 60% (v/v) methanol/water, a highly helical state (H) was realized. The H state had a helical content much higher than the native state, monitored by far-W CD spectroscopy, and had no specific tertiary structure, monitored both by near-UV CD and N M R spectroscopy. The radius of gyration in the H state, 24.9 A, was significantly larger than that in the native state (15.7 A). The Kratky plot for the H state did not show a clear peak and was quite similar to that for the urea-denatured state, indicating a complete lack of globularity. Thus we conclude that the H state has a considerably expanded, flexible broken rod-like conformation which is clearly distinguishable from the "molten globule" state. The stability of both N and H states depends on pH and methanol concentration. Thus a phase diagram involving N and H was constructed.

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Section: Structural Characterization Of the Helical Denatured State (H) At High Concentrations Of Methanolmentioning

confidence: 67%

mentioning

confidence: 89%

The methanol‐induced transition and the expanded helical conformation in hen lysozyme

et al. 1998

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“…Consistent with what is observed in mammalian cells, we found CHX treatment blocks Hsf1 activation in oxidative stress induced by diamide, and proteasome inhibition by MG132. Additionally, CHX blocks Hsf1 activation by heat (Masser et al, 2019), the denaturant ethanol (Herskovits et al, 1970) and the ribosome assembly inhibitor diazaborine (Tye et al, 2019). These stresses cover a broad range of known proteotoxic conditions known to activate Hsf1, thus showing the consistent requirement for concurrent protein synthesis for Hsf1 activation (Morano et al, 2012;West et al, 2012).…”

Section: Results: Translation Inhibition By Cycloheximide (Chx) Prevents Hsf1 Activation Across Diverse Proteotoxic Stressorsmentioning

confidence: 99%

“…Diazaborine interferes with the assembly of newlysynthesized ribosomal proteins (Loibl et al, 2014). Heat shock and ethanol, on the other hand, may biochemically interfere with the folding of nascent chains by decreasing the enthalpic advantage of burying hydrophobic segments, allowing for interaction of exposed hydrophobic segments between incompletely folded polypeptides (Herskovits et al, 1970). A key job of the proteasome is to clear out a subset of newly-synthesized proteins, such as those protein complex subunits that are produced in stoichiometric excess (Duttler et al, 2013;McShane et al, 2016).…”

Section: Discussionmentioning

confidence: 99%

Hsf1 activation by proteotoxic stress requires concurrent protein synthesis

Tye

Churchman

2021

MBoC

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Heat shock factor 1 (Hsf1) activation is responsible for increasing the abundance of protein folding chaperones and degradation machinery in response to proteotoxic conditions that give rise to misfolded or aggregated proteins. Here, we systematically explored the link between concurrent protein synthesis and proteotoxic stress in the budding yeast, S. cerevisiae. Consistent with prior work, inhibiting protein synthesis before inducing proteotoxic stress prevents Hsf1 activation, which we demonstrated across a broad array of stresses and validate using orthogonal means of blocking protein synthesis. However, other stress-dependent transcription pathways remained activatable under conditions of translation inhibition. Titrating the protein denaturant ethanol to a higher concentration results in Hsf1 activation in the absence of translation, suggesting extreme protein folding stress can induce proteotoxicity independent of protein synthesis. Furthermore, we demonstrate this connection under physiological conditions where protein synthesis occurs naturally at reduced rates. We find that disrupting the assembly or subcellular localization of newly synthesized proteins is sufficient to activate Hsf1. Thus, new proteins appear to be especially sensitive to proteotoxic conditions, and we propose that their aggregation may represent the bulk of the signal that activates Hsf1 in the wake of these insults.

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“…The extent of aggregation roughly follows the relative polarity values of the solvents ( Reichardt and Welton, 2011 ) ( Figure 3 B), and the activity loss of free cytochrome c trends with the size of native cytochrome c aggregates ( Figure 3 C). Previous studies have reported that cytochrome c undergoes conformational changes and denaturation in many solvents, including alcohols and acetonitrile ( Amin et al., 2016 ; Herskovits et al., 1970 ), and nonfunctional unfolded conformations of the enzyme aggregate more readily than folded states ( Lin et al., 2016 ; Furkan et al., 2016 ). Native and solvent-treated cytochrome c shares similar diffuse-reflective UV-Vis solid-state spectra ( Figure S5 ), showing low-spin ferricytochrome c as the predominate active center without major changes from the native state ( Collinson and Bowden, 1992 ).…”

Section: Resultsmentioning

confidence: 99%