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Lysine pyrrolation is a naturally-occurring covalent modification involved in the production of DNA mimic proteins.

Miyashita H, Chikazawa M, Otaki N, Hioki Y, Shimozu Y, Nakashima F, Shibata T, Hagihara Y, Maruyama S, Matsumi N, Uchida K - Sci Rep (2014)

Bottom Line: Covalent modification of proteins exerts significant effects on their chemical properties and has important functional and regulatory consequences.This previously unreported property of proteins was initially discovered when the γ-ketoaldehydes were identified as a source of the proteins stained by the DNA intercalators.Using 1,4-butanedial, the simplest γ-ketoaldehyde, we characterized the structural and chemical criteria governing the recognition of the modified proteins by the DNA intercalators and identified N(ε)-pyrrolelysine as a key adduct.

View Article: PubMed Central - PubMed

Affiliation: Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan.

ABSTRACT
Covalent modification of proteins exerts significant effects on their chemical properties and has important functional and regulatory consequences. We now report the identification and verification of an electrically-active form of modified proteins recognized by a group of small molecules commonly used to interact with DNA. This previously unreported property of proteins was initially discovered when the γ-ketoaldehydes were identified as a source of the proteins stained by the DNA intercalators. Using 1,4-butanedial, the simplest γ-ketoaldehyde, we characterized the structural and chemical criteria governing the recognition of the modified proteins by the DNA intercalators and identified N(ε)-pyrrolelysine as a key adduct. Unexpectedly, the pyrrolation conferred an electronegativity and electronic properties on the proteins that potentially constitute an electrical mimic to the DNA. In addition, we found that the pyrrolated proteins indeed triggered an autoimmune response and that the production of specific antibodies against the pyrrolated proteins was accelerated in human systemic lupus erythematosus. These findings and the apparent high abundance of N(ε)-pyrrolelysine in vivo suggest that protein pyrrolation could be an endogenous source of DNA mimic proteins, providing a possible link connecting protein turnover and immune disorders.

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Related in: MedlinePlus

Fluorescence spectra of SG free in solution and in complex with dsDNA or BDA-modified BSA.(a) Fluorescence spectra of SG in complex with dsDNA. dsDNA (1 mg/ml) was incubated with SG (100 nM) in TAE buffer for 30 min. (b) Fluorescence spectra of SG in complex with BDA-modified BSA. BSA or BDA-modified BSA (1 mg/ml) were incubated with SG (500 nM) in TAE buffer for 30 min. (c) A schematic illustration of the binding of DNA intercalators to the pyrrolated proteins.
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f3: Fluorescence spectra of SG free in solution and in complex with dsDNA or BDA-modified BSA.(a) Fluorescence spectra of SG in complex with dsDNA. dsDNA (1 mg/ml) was incubated with SG (100 nM) in TAE buffer for 30 min. (b) Fluorescence spectra of SG in complex with BDA-modified BSA. BSA or BDA-modified BSA (1 mg/ml) were incubated with SG (500 nM) in TAE buffer for 30 min. (c) A schematic illustration of the binding of DNA intercalators to the pyrrolated proteins.

Mentions: It has been established that intercalation between base pairs and stabilization of the electrostatic SG/dsDNA complex contributes to the increased SG affinity to dsDNA16. In a manner similar to the SG/dsDNA, the fluorescence of SG was dramatically enhanced by the BDA-modified proteins (Fig. 3a, b). A very limited overall alteration in the secondary structure of the protein after treatment with the γ-ketoaldehydes, such as 4-oxo-nonanal and BDA, was observed (Fig. S8). These data support the hypothesis that the protein-bound pyrroles might be involved in the structural and chemical criteria governing the recognition of the modified proteins by the DNA-binding molecules (Fig. 3c).


Lysine pyrrolation is a naturally-occurring covalent modification involved in the production of DNA mimic proteins.

Miyashita H, Chikazawa M, Otaki N, Hioki Y, Shimozu Y, Nakashima F, Shibata T, Hagihara Y, Maruyama S, Matsumi N, Uchida K - Sci Rep (2014)

Fluorescence spectra of SG free in solution and in complex with dsDNA or BDA-modified BSA.(a) Fluorescence spectra of SG in complex with dsDNA. dsDNA (1 mg/ml) was incubated with SG (100 nM) in TAE buffer for 30 min. (b) Fluorescence spectra of SG in complex with BDA-modified BSA. BSA or BDA-modified BSA (1 mg/ml) were incubated with SG (500 nM) in TAE buffer for 30 min. (c) A schematic illustration of the binding of DNA intercalators to the pyrrolated proteins.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4061549&req=5

f3: Fluorescence spectra of SG free in solution and in complex with dsDNA or BDA-modified BSA.(a) Fluorescence spectra of SG in complex with dsDNA. dsDNA (1 mg/ml) was incubated with SG (100 nM) in TAE buffer for 30 min. (b) Fluorescence spectra of SG in complex with BDA-modified BSA. BSA or BDA-modified BSA (1 mg/ml) were incubated with SG (500 nM) in TAE buffer for 30 min. (c) A schematic illustration of the binding of DNA intercalators to the pyrrolated proteins.
Mentions: It has been established that intercalation between base pairs and stabilization of the electrostatic SG/dsDNA complex contributes to the increased SG affinity to dsDNA16. In a manner similar to the SG/dsDNA, the fluorescence of SG was dramatically enhanced by the BDA-modified proteins (Fig. 3a, b). A very limited overall alteration in the secondary structure of the protein after treatment with the γ-ketoaldehydes, such as 4-oxo-nonanal and BDA, was observed (Fig. S8). These data support the hypothesis that the protein-bound pyrroles might be involved in the structural and chemical criteria governing the recognition of the modified proteins by the DNA-binding molecules (Fig. 3c).

Bottom Line: Covalent modification of proteins exerts significant effects on their chemical properties and has important functional and regulatory consequences.This previously unreported property of proteins was initially discovered when the γ-ketoaldehydes were identified as a source of the proteins stained by the DNA intercalators.Using 1,4-butanedial, the simplest γ-ketoaldehyde, we characterized the structural and chemical criteria governing the recognition of the modified proteins by the DNA intercalators and identified N(ε)-pyrrolelysine as a key adduct.

View Article: PubMed Central - PubMed

Affiliation: Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan.

ABSTRACT
Covalent modification of proteins exerts significant effects on their chemical properties and has important functional and regulatory consequences. We now report the identification and verification of an electrically-active form of modified proteins recognized by a group of small molecules commonly used to interact with DNA. This previously unreported property of proteins was initially discovered when the γ-ketoaldehydes were identified as a source of the proteins stained by the DNA intercalators. Using 1,4-butanedial, the simplest γ-ketoaldehyde, we characterized the structural and chemical criteria governing the recognition of the modified proteins by the DNA intercalators and identified N(ε)-pyrrolelysine as a key adduct. Unexpectedly, the pyrrolation conferred an electronegativity and electronic properties on the proteins that potentially constitute an electrical mimic to the DNA. In addition, we found that the pyrrolated proteins indeed triggered an autoimmune response and that the production of specific antibodies against the pyrrolated proteins was accelerated in human systemic lupus erythematosus. These findings and the apparent high abundance of N(ε)-pyrrolelysine in vivo suggest that protein pyrrolation could be an endogenous source of DNA mimic proteins, providing a possible link connecting protein turnover and immune disorders.

Show MeSH
Related in: MedlinePlus