Effects of molecular crowding environment on the acquisition of toxic properties of wild-type SOD1

Takahashi, Akira; Nagao, Chioko; Murakami, Kohji; Kuroi, Kunisato; Nakabayashi, Takakazu

doi:10.1016/j.bbagen.2019.07.010

Cited by 13 publications

(27 citation statements)

References 42 publications

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“…Fluorescent DCF is then generated by the oxidation reaction between DCFH and ROS generated from H 2 O 2 catalyzed by SOD1. The DCF fluorescence intensity therefore reflects the pro-oxidant activity of SOD1 [ 27 , 28 , 29 , 30 , 31 , 32 ]. Figure 2 A shows the example of the increase in the DCF fluorescence due to the pro-oxidant activity.…”

Section: Resultsmentioning

confidence: 99%

“…(E,E)-H43R acquires the pro-oxidant activity after the incubation at 37 °C and subsequent addition of Cu 2+ . As shown in Figure 2 A, the DCF fluorescence of (E,E)-H43R strongly increased after 90 min incubation at 37 °C and subsequent Cu 2+ addition, indicating that the pro-oxidant activity was acquired following the denaturation and Cu 2+ rebinding [ 27 , 28 , 29 , 30 , 31 , 32 ].…”

Section: Resultsmentioning

confidence: 99%

“…We have systematically investigated the acquisition of the pro-oxidant activity of denatured SOD1, a behavior that is opposite to its usual dismutation function [ 27 , 28 , 29 , 30 , 31 , 32 ]. We showed that the metal-depleted (apo) SOD1 mutants ((E,E)-SOD1, hereafter SOD1 is referred to as (m 1 ,m 2 )-SOD1, where (m 1 ,m 2 ) means coordinated metal ions in the Cu- and Zn-binding sites, respectively, and E is empty) were unfolded at 37 °C and these denatured SOD1 exhibited the pro-oxidant activity after rebinding Cu 2+ .…”

Section: Introductionmentioning

confidence: 99%

“…Some ALS-linked SOD1 mutants can be denatured at a physiological temperature of 37 °C when the metal ions are removed to be their (E,E) forms [ 27 , 28 , 29 , 30 , 31 , 32 ]. The aggregation of ALS-linked SOD1 mutants at physiological temperatures also occurs only after the demetallation and the subsequent denaturation [ 19 ].…”

Section: Introductionmentioning

confidence: 99%

“…The pro-oxidant activity was observed for (E,E)-SOD1, irrespective of mutation, following the denaturation and the subsequent re-binding of Cu 2+ [ 27 , 28 , 29 , 30 , 31 , 32 ]. The finding of metal-depleted SOD1 in ALS model mice [ 34 ] supports a model in which (E,E)-SOD1 is a precursor to cytotoxic expression.…”

Section: Introductionmentioning

confidence: 99%

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Pro-Oxidant Activity of an ALS-Linked SOD1 Mutant in Zn-Deficient Form

et al. 2020

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Cu, Zn superoxide dismutase (SOD1) is a representative antioxidant enzyme that catalyzes dismutation of reactive oxygen species in cells. However, (E,E)-SOD1 mutants in which both copper and zinc ions were deleted exhibit pro-oxidant activity, contrary to their antioxidant nature, at physiological temperatures, following denaturation and subsequent recombination of Cu2+. This oxidative property is likely related to the pathogenesis of amyotrophic lateral sclerosis (ALS); however, the mechanism by which Cu2+ re-binds to the denatured (E,E)-SOD1 has not been elucidated, since the concentration of free copper ions in cells is almost zero. In this study, we prepared the (Cu,E) form in which only a zinc ion was deleted using ALS-linked mutant H43R (His43→Arg) and found that (Cu,E)-H43R showed an increase in the pro-oxidant activity even at physiological temperature. The increase in the pro-oxidant activity of (Cu,E)-H43R was also observed in solution mimicking intracellular environment and at high temperature. These results suggest that the zinc-deficient (Cu,E) form can contribute to oxidative stress in cells, and that the formation of (E,E)-SOD1 together with the subsequent Cu2+ rebinding is not necessary for the acquisition of the pro-oxidant activity.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Pro-Oxidant Activity of an ALS-Linked SOD1 Mutant in Zn-Deficient Form

et al. 2020

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Label‐Free Imaging of Intracellular Temperature by Using the O−H Stretching Raman Band of Water

2020

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We propose a label‐free method for measuring intracellular temperature using a Raman image of a cell in the O−H stretching band. Raman spectra of cultured cells and the medium were first measured at various temperatures using a Raman microscope and the intensity ratio of the two regions of the O−H stretching band was calculated. The intensity ratio varies linearly with temperature in both the medium and cells, and the resulting calibration lines allow simultaneous visualization of both intracellular and extracellular temperatures in a label‐free manner. We applied this method to the measurement of temperature changes after the introduction of FCCP (carbonyl cyanide‐p‐trifluoromethoxyphenylhydrazone) in living cells. We observed a temperature rise in the cytoplasm and succeeded in obtaining an image of the change in intracellular temperature after the FCCP treatment.

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Label‐Free Imaging of Intracellular Temperature by Using the O−H Stretching Raman Band of Water

2020

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We propose a label-free method for measuring intracellular temperature using a Raman image of a cell in the OÀH stretching band. Raman spectra of cultured cells and the medium were first measured at various temperatures using a Raman microscope and the intensity ratio of the two regions of the O À H stretching band was calculated. The intensity ratio varies linearly with temperature in both the medium and cells, and the resulting calibration lines allow simultaneous visualization of both intracellular and extracellular temperatures in a label-free manner. We applied this method to the measurement of temperature changes after the introduction of FCCP (carbonyl cyanide-p-trifluoromethoxyphenylhydrazone) in living cells. We observed a temperature rise in the cytoplasm and succeeded in obtaining an image of the change in intracellular temperature after the FCCP treatment.Intracellular temperature is an essential parameter for understanding physiological phenomena, since all physiological functions involve the generation or absorption of heat. Cellular events such as respiration and cell division have now been examined and understood from the viewpoint of temperature change. The mechanism by which cells detect extracellular temperature [1,2] and transmit it to cell temperature homeostasis has also been studied extensively. [3] Sensing of intracellular temperature is applicable for the diagnosis of diseases, elucidation of disease onset mechanisms, and development of new target drugs.In recent years, the measurement of intracellular temperature has become one of the main topics of chemistry and biophysics, triggered in part by the development of various thermosensitive fluorescent dye molecules. [4][5][6][7][8][9][10][11] These dyes exhibit marked changes in their fluorescence intensity and/or fluorescence lifetime in response to the surrounding temperature, which can be used for evaluating and visualizing the temperature inside a cell. For example, temperature differences among cellular components [4] and heat production in the endoplasmic reticulum by Ca ions [7] have been reported using appropriate thermosensitive fluorescent dyes. However, temperature measurements using exogenous fluorescent dyes have disadvantages, such as the need for pretreatment for dye staining and changes in the intracellular environment with the introduction of dyes. Photobleaching of stained dyes increases the uncertainty of the evaluated temperature. It should be noted that the fluorescence intensity (lifetime) of these dyes depends not only on the surrounding temperature but also on other environmental factors such as ion concentration, viscosity and interaction with biological molecules. Therefore, careful attention must be paid to the estimation of intracellular temperature by fluorescence, [12] since the intracellular environment varies depending on the state of the cell. Furthermore, it is difficult to measure the temperature outside the region where fluorescent molecules are localized. The temperature of the surrounding medium cannot...

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Effects of molecular crowding environment on the acquisition of toxic properties of wild-type SOD1

Cited by 13 publications

References 42 publications

Pro-Oxidant Activity of an ALS-Linked SOD1 Mutant in Zn-Deficient Form

Pro-Oxidant Activity of an ALS-Linked SOD1 Mutant in Zn-Deficient Form

Label‐Free Imaging of Intracellular Temperature by Using the O−H Stretching Raman Band of Water

Label‐Free Imaging of Intracellular Temperature by Using the O−H Stretching Raman Band of Water

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