Wyniki wyszukiwania - Biblioteka Nauki

1

Homocysteine thiolactone affects protein ubiquitination in yeast

100%

Bretes E. , Zimny J.

Acta Biochimica Polonica

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2013

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tom 60

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nr 3

485-488

EN

The formation of homocysteine thiolactone (HcyTl) from homocysteine occurs in all examined so far organisms including bacteria, yeast, and humans. Protein N-homocysteinylation at the ε-amino group of lysine is an adverse result of HcyTl accumulation. Since tagging of proteins by ubiquitination before their proteasomal degradation takes place at the same residue, we wondered how N-homocysteinylation may affect the ubiquitination of proteins. We used different yeast strains carrying mutations in genes involved in the homocysteine metabolism. We found positive correlation between the concentration of endogenous HcyTl and the concentration of ubiquitinated proteins. This suggests that N-homocysteinylation of proteins apparently does not preclude but rather promotes their decomposition.

2

Homocysteine thiolactone affects protein ubiquitination in yeast

80%

Bretes E. , Zimny J.

Acta Biochimica Polonica

|

2013

|

tom 60

|

nr 3

EN

The formation of homocysteine thiolactone (HcyTl) from homocysteine occurs in all examined so far organisms including bacteria, yeast, and humans. Protein N-homocysteinylation at the ε-amino group of lysine is an adverse result of HcyTl accumulation. Since tagging of proteins by ubiquitination before their proteasomal degradation takes place at the same residue, we wondered how N-homocysteinylation may affect the ubiquitination of proteins. We used different yeast strains carrying mutations in genes involved in the homocysteine metabolism. We found positive correlation between the concentration of endogenous HcyTl and the concentration of ubiquitinated proteins. This suggests that N-homocysteinylation of proteins apparently does not preclude but rather promotes their decomposition.

3

The disturbance of hemostasis induced by hyperhomocysteinemia; the role of antioxidants

51%

Malinowska J. , Kolodziejczyk J. , Olas B.

Acta Biochimica Polonica

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2012

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tom 59

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nr 2

185-194

EN

Elevated concentration of homocysteine (Hcy) in human tissues, definied as hyperhomocysteinemia has been correlated with some diseases, such as cardiovascular, neurodegenerative, and kidney disorders. Homocysteine occurs in human blood plasma in several forms, including the most reactive one, the homocysteine thiolactone (HTL) - a cyclic thioester, which represents up to 0.29% of total plasma Hcy. In the article, the effects of hyperhomocysteinemia on the complex process of hemostasis, which regulates the flowing properties of blood, are described. Possible interactions of homocysteine and its different derivatives, including homocysteine thiolactone, with the major components of hemostasis such as endothelial cells, blood platelets, plasmatic fibrinogen and plasminogen, are also discussed. Modifications of hemostatic proteins (N-homocysteinylation or S-homocysteinylation) induced by Hcy or its thiolactone seem to be the main cause of homocysteine biotoxicity in hemostatic abnormalities. It is suggested that Hcy and HTL may also act as oxidants, but various polyphenolic antioxidants are able to inhibit the oxidative damage induced by Hcy or HTL. We also discuss the role of phenolic antioxidants in hyperhomocysteinemia -induced changes in hemostasis.

4

Chromatografia gazowa w analizie moczu i śliny na zawartość tiolaktonu homocysteiny

41%

Wieczorek M. , Piechocka J. , Głowacki R.

Analityka : nauka i praktyka

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2021

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tom nr 1

16--22

PL

Najnowsze badania dostarczają przekonujących dowodów, że podczas oznaczania HTL w próbkach biologicznych technika GC MS może stanowić przydatne i precyzyjne narzędzie, konkurencyjne w stosunku do tych opartych na technikach separacji w fazie ciekłej.