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The effects of endogenous non-peptide molecule isatin and hydrogen peroxide on proteomic profiling of rat brain amyloid-β binding proteins: relevance to Alzheimer's disease?

Medvedev AE, Buneeva OA, Kopylov AT, Gnedenko OV, Medvedeva MV, Kozin SA, Ivanov AS, Zgoda VG, Makarov AA - Int J Mol Sci (2014)

Bottom Line: Proteomic profiling of rat brain homogenates, performed in this study, resulted in identification of 89 individual intracellular amyloid-binding proteins, and approximately 25% of them were proteins that we had previously identified as specifically binding to isatin, an endogenous neuroprotector molecule.A significant proportion of the amyloid-binding proteins (more than 30%) are differentially expressed or altered/oxidatively modified in AD patients.The effects of hydrogen peroxide and isatin have been confirmed in optical biosensor experiments with purified glyceraldehyde-3-phosphate dehydrogenase, one of the known crucial amyloid-β binding proteins (also identified in this study).

View Article: PubMed Central - PubMed

Affiliation: Department of Proteomic Research and Mass Spectrometry, Institute of Biomedical Chemistry, 10 Pogodinskaya Street, Moscow 119121, Russia. professor57@yandex.ru.

ABSTRACT
The amyloid-β peptide is considered as a key player in the development and progression of Alzheimer's disease (AD). Although good evidence exists that amyloid-β accumulates inside cells, intracellular brain amyloid-binding proteins remain poorly characterized. Proteomic profiling of rat brain homogenates, performed in this study, resulted in identification of 89 individual intracellular amyloid-binding proteins, and approximately 25% of them were proteins that we had previously identified as specifically binding to isatin, an endogenous neuroprotector molecule. A significant proportion of the amyloid-binding proteins (more than 30%) are differentially expressed or altered/oxidatively modified in AD patients. Incubation of brain homogenates with 70 µM hydrogen peroxide significantly influenced the profile of amyloid-β binding proteins and 0.1 mM isatin decreased the number of identified amyloid-β binding proteins both in control and hydrogen peroxide treated brain homogenates. The effects of hydrogen peroxide and isatin have been confirmed in optical biosensor experiments with purified glyceraldehyde-3-phosphate dehydrogenase, one of the known crucial amyloid-β binding proteins (also identified in this study). Data obtained suggest that isatin protects crucial intracellular protein targets against amyloid binding, and possibly favors intracellular degradation of this protein via preventing formation of amyloid-β oligomers described in the literature for some isatin derivatives.

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The effect of GAPDH oxidation on Kd values for GAPDH interaction with immobilized actin (A) and amyloid-beta (B). Data represent mean ± SEM from 3–5 independent experiments. Asterisks show statistically significant differences in Kd values for intact and oxidized GAPDH (* p < 0.05; ** p < 0.01) evaluated by paired Student’s t-test.
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ijms-16-00476-f003: The effect of GAPDH oxidation on Kd values for GAPDH interaction with immobilized actin (A) and amyloid-beta (B). Data represent mean ± SEM from 3–5 independent experiments. Asterisks show statistically significant differences in Kd values for intact and oxidized GAPDH (* p < 0.05; ** p < 0.01) evaluated by paired Student’s t-test.

Mentions: The calculated Kd value for the GAPDH amyloid-β complex of 0.22 ± 0.02 µM was in the range of Kd values for GAPDH complexes with actin reported in the literature [54]. In our experimental conditions GAPDH affinity to amyloid beta was even higher than to actin (the Kd value of 1.22 ± 0.2 µM, p < 0.01 versus the Kd value for GAPDH binding to amyloid-β) (Figure 2). Addition of the GAPDH cofactor, NAD (oxidized nicotineamide adenine dinucleotide) (0.01–5 mM), did not influence the behavior of the biosensor response implying lack of any influence of NAD (at least at physiological concentrations) on GAPDH binding to amyloid-β (data not shown), while 0.1 mM isatin decreased this binding and increased the Kd values (Figure 3).


The effects of endogenous non-peptide molecule isatin and hydrogen peroxide on proteomic profiling of rat brain amyloid-β binding proteins: relevance to Alzheimer's disease?

Medvedev AE, Buneeva OA, Kopylov AT, Gnedenko OV, Medvedeva MV, Kozin SA, Ivanov AS, Zgoda VG, Makarov AA - Int J Mol Sci (2014)

The effect of GAPDH oxidation on Kd values for GAPDH interaction with immobilized actin (A) and amyloid-beta (B). Data represent mean ± SEM from 3–5 independent experiments. Asterisks show statistically significant differences in Kd values for intact and oxidized GAPDH (* p < 0.05; ** p < 0.01) evaluated by paired Student’s t-test.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4307257&req=5

ijms-16-00476-f003: The effect of GAPDH oxidation on Kd values for GAPDH interaction with immobilized actin (A) and amyloid-beta (B). Data represent mean ± SEM from 3–5 independent experiments. Asterisks show statistically significant differences in Kd values for intact and oxidized GAPDH (* p < 0.05; ** p < 0.01) evaluated by paired Student’s t-test.
Mentions: The calculated Kd value for the GAPDH amyloid-β complex of 0.22 ± 0.02 µM was in the range of Kd values for GAPDH complexes with actin reported in the literature [54]. In our experimental conditions GAPDH affinity to amyloid beta was even higher than to actin (the Kd value of 1.22 ± 0.2 µM, p < 0.01 versus the Kd value for GAPDH binding to amyloid-β) (Figure 2). Addition of the GAPDH cofactor, NAD (oxidized nicotineamide adenine dinucleotide) (0.01–5 mM), did not influence the behavior of the biosensor response implying lack of any influence of NAD (at least at physiological concentrations) on GAPDH binding to amyloid-β (data not shown), while 0.1 mM isatin decreased this binding and increased the Kd values (Figure 3).

Bottom Line: Proteomic profiling of rat brain homogenates, performed in this study, resulted in identification of 89 individual intracellular amyloid-binding proteins, and approximately 25% of them were proteins that we had previously identified as specifically binding to isatin, an endogenous neuroprotector molecule.A significant proportion of the amyloid-binding proteins (more than 30%) are differentially expressed or altered/oxidatively modified in AD patients.The effects of hydrogen peroxide and isatin have been confirmed in optical biosensor experiments with purified glyceraldehyde-3-phosphate dehydrogenase, one of the known crucial amyloid-β binding proteins (also identified in this study).

View Article: PubMed Central - PubMed

Affiliation: Department of Proteomic Research and Mass Spectrometry, Institute of Biomedical Chemistry, 10 Pogodinskaya Street, Moscow 119121, Russia. professor57@yandex.ru.

ABSTRACT
The amyloid-β peptide is considered as a key player in the development and progression of Alzheimer's disease (AD). Although good evidence exists that amyloid-β accumulates inside cells, intracellular brain amyloid-binding proteins remain poorly characterized. Proteomic profiling of rat brain homogenates, performed in this study, resulted in identification of 89 individual intracellular amyloid-binding proteins, and approximately 25% of them were proteins that we had previously identified as specifically binding to isatin, an endogenous neuroprotector molecule. A significant proportion of the amyloid-binding proteins (more than 30%) are differentially expressed or altered/oxidatively modified in AD patients. Incubation of brain homogenates with 70 µM hydrogen peroxide significantly influenced the profile of amyloid-β binding proteins and 0.1 mM isatin decreased the number of identified amyloid-β binding proteins both in control and hydrogen peroxide treated brain homogenates. The effects of hydrogen peroxide and isatin have been confirmed in optical biosensor experiments with purified glyceraldehyde-3-phosphate dehydrogenase, one of the known crucial amyloid-β binding proteins (also identified in this study). Data obtained suggest that isatin protects crucial intracellular protein targets against amyloid binding, and possibly favors intracellular degradation of this protein via preventing formation of amyloid-β oligomers described in the literature for some isatin derivatives.

Show MeSH
Related in: MedlinePlus