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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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Related in: MedlinePlus

Subdivision of amyloid-binding proteins identified in brain homogenates by their functions: Numbers indicate total number of proteins in each group and numbers in parentheses show the percentage of the total number of identified proteins.
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ijms-16-00476-f001: Subdivision of amyloid-binding proteins identified in brain homogenates by their functions: Numbers indicate total number of proteins in each group and numbers in parentheses show the percentage of the total number of identified proteins.

Mentions: Loading of cleared Triton X-100 lysates of whole brain homogenate onto the affinity sorbent, amyloid-beta-Affi-Gel 10, followed by wash with 50 mM potassium phosphate buffer, pH 7.4, resulted in adsorption of 10.4% of the total protein applied. The control Affi-Gel 10 lacking the affinity ligand bound not more than 4% of the total protein applied. This suggests that about 6% of homogenate proteins specifically bound to the affinity sorbent. Subsequent elution of adsorbed proteins followed by their proteomic analysis resulted in identification of at least 89 individual intracellular β-amyloid binding proteins specifically bound to the affinity sorbent (Table S1). They have different intracellular localization and functionally, the identified proteins can be subdivided into the following groups (Figure 1): (i) Energy generation and carbohydrate metabolism; (ii) Cytoskeleton formation and exocytosis/trafficking; (iii) Regulation of gene expression, cell division and differentiation; (iv) Signal transduction and regulation of enzyme activity; (v) Antioxidant and protection proteins/enzymes; (vi) Metabolism of amino acids and other nitrogenous compounds; and (vii) Lipid metabolism. It is particularly significant that metabolic consequences of amyloid-beta interaction with some of these proteins (e.g., catalase, cytochrome oxidase) have already been documented and analyzed in the literature [17,18].


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)

Subdivision of amyloid-binding proteins identified in brain homogenates by their functions: Numbers indicate total number of proteins in each group and numbers in parentheses show the percentage of the total number of identified proteins.
© Copyright Policy
Related In: Results  -  Collection

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

ijms-16-00476-f001: Subdivision of amyloid-binding proteins identified in brain homogenates by their functions: Numbers indicate total number of proteins in each group and numbers in parentheses show the percentage of the total number of identified proteins.
Mentions: Loading of cleared Triton X-100 lysates of whole brain homogenate onto the affinity sorbent, amyloid-beta-Affi-Gel 10, followed by wash with 50 mM potassium phosphate buffer, pH 7.4, resulted in adsorption of 10.4% of the total protein applied. The control Affi-Gel 10 lacking the affinity ligand bound not more than 4% of the total protein applied. This suggests that about 6% of homogenate proteins specifically bound to the affinity sorbent. Subsequent elution of adsorbed proteins followed by their proteomic analysis resulted in identification of at least 89 individual intracellular β-amyloid binding proteins specifically bound to the affinity sorbent (Table S1). They have different intracellular localization and functionally, the identified proteins can be subdivided into the following groups (Figure 1): (i) Energy generation and carbohydrate metabolism; (ii) Cytoskeleton formation and exocytosis/trafficking; (iii) Regulation of gene expression, cell division and differentiation; (iv) Signal transduction and regulation of enzyme activity; (v) Antioxidant and protection proteins/enzymes; (vi) Metabolism of amino acids and other nitrogenous compounds; and (vii) Lipid metabolism. It is particularly significant that metabolic consequences of amyloid-beta interaction with some of these proteins (e.g., catalase, cytochrome oxidase) have already been documented and analyzed in the literature [17,18].

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