von Ana Catarina Ribeiro Carrão
Statistik und Sichtungsnachweis dieser Seite findet sich am Artikelende
| [1.] Arc/Fragment 022 01 - Diskussion Zuletzt bearbeitet: 2014-02-26 22:19:13 Schumann | Arc, BauernOpfer, Bedard Krause 2007, Fragment, Gesichtet, SMWFragment, Schutzlevel sysop |
|
|
|
| Untersuchte Arbeit: Seite: 22, Zeilen: 1-13 |
Quelle: Bedard Krause 2007 Seite(n): 246, Zeilen: l.col: 21ff |
|---|---|
| [Other elements in the cascade of ROS generation include the reaction of superoxide with nitric oxide to form peroxynitrite (ONOO-), the peroxidase-catalyzed formation of hypochlorous acid] (HOCl) from hydrogen peroxide, and the iron-catalyzed Fenton reaction leading to the generation of hydroxyl radical58. ROS avidly interact with a large number of molecules including other small inorganic molecules as well as proteins, lipids, carbohydrates, and nucleic acids. Through such interactions, ROS may irreversibly destroy or alter the function of the target molecule and consequently, ROS have been increasingly identified as major contributors to damage in biological organisms. However, ROS are involved not only in cellular damage and killing of pathogens, but also in a large number of reversible regulatory signalling processes in virtually all cells and tissues59. The physiological generation of ROS can occur as a result of other biological reactions. For example, ROS generation occurs as a byproduct in the mitochondria, peroxisomes, cytochrome P-450, and other cellular elements58. The phagocyte NADPH oxidase was the first identified example of a system that generates ROS not as a byproduct, but rather as the primary function of this enzyme system59.
58. Thannickal VJ, Fanburg BL. Reactive oxygen species in cell signaling. Am J Physiol Lung Cell Mol Physiol. 2000;279:L1005-1028. 59. Bedard K, Krause K-H. The NOX Family of ROS-Generating NADPH Oxidases: Physiology and Pathophysiology. Physiol. Rev. 2007;87:245-313. |
Other elements in the cascade of ROS generation include the reaction of superoxide with nitric oxide to form peroxynitrite, the peroxidase-catalyzed formation of hypochlorous acid from hydrogen peroxide, and the iron-catalyzed Fenton reaction leading to the generation of hydroxyl radical (468, 874).
ROS avidly interact with a large number of molecules including other small inorganic molecules as well as proteins, lipids, carbohydrates, and nucleic acids. Through such interactions, ROS may irreversibly destroy or alter the function of the target molecule. Consequently, ROS have been increasingly identified as major contributors to damage in biological organisms. [...] In fact, ROS are involved not only in cellular damage and killing of pathogens, but also in a large number of reversible regulatory processes in virtually all cells and tissues. [...] [...] The physiological generation of ROS can occur as a byproduct of other biological reactions. ROS generation as a byproduct occurs with mitochondria, peroxisomes, cytochrome P-450, and other cellular elements (50, 307, 314, 356, 588, 636, 715, 791, 874). However, the phagocyte NADPH oxidase was the first identified example of a system that generates ROS not as a byproduct, but rather as the primary function of the enzyme system. [...] 874. Thannickal VJ, Fanburg BL. Reactive oxygen species in cell signaling. Am J Physiol Lung Cell Mol Physiol 279: L1005–L1028, 2000. [...] |
The copied text starts on the previous page: see: Arc/Fragment_021_22. The source is given twice, but still it is not clear to the reader that everything is taken more or less verbatim from the source, including the reference to Thannickal & Fanburg (2000). |
|
| [2.] Arc/Fragment 022 15 - Diskussion Zuletzt bearbeitet: 2014-02-26 21:34:13 Graf Isolan | Arc, BauernOpfer, Fragment, Gesichtet, Quinn and Gauss 2004, SMWFragment, Schutzlevel sysop |
|
|
|
| Untersuchte Arbeit: Seite: 22, Zeilen: 15-24 |
Quelle: Quinn and Gauss 2004 Seite(n): 761, Zeilen: l.col: 23ff |
|---|---|
| In general, the best characterized plasma membrane oxidase is the phagocytic NADPH oxidase, a multicomponent enzyme composed of four oxidase-specific proteins (p22phox, p47phox, p67phox, and gp91phox) and a GTPase (Rac1/2). One other oxidase-specific protein (p40phox) and a second GTPase (Rap1A) have also been shown to play roles in regulating oxidase activity; however, their specific functions are still not well understood60. Originally, the nomenclature for the various components differed throughout the literature (Table 1); however, the generally accepted nomenclature for the phagocyte oxidase specific components now includes the suffix phox, which refers to phagocyte oxidase61. The only one exception is gp91phox, which has also been named NADPH oxidase 2 (Nox2)62.
60. Quinn MT, Gauss KA. Structure and regulation of the neutrophil respiratory burst oxidase: comparison with nonphagocyte oxidases. J Leukoc Biol. 2004;76:760-781. 61. Babior BM. NADPH oxidase. Current Opinion in Immunology. 2004;16:42-47. 62. Lambeth JD, Cheng G, Arnold RS, Edens WA. Novel homologs of gp91phox. Trends Biochem Sci. 2000;25:459-461. |
It is now generally accepted that the core NADPH oxidase enzyme is composed of four oxidase-specific proteins (p22phox, p47phox, p67phox, and gp91phox) and a GTPase (Rac1/2). One other oxidase-specific protein (p40phox) and a second GTPase (Rap1A) have also been shown to play roles in regulating oxidase activity; however, their specific functions are still not well understood. Originally, the nomenclature for the various components differed throughout the literature; however, the generally accepted nomenclature for the phagocyte oxidasespecific components now includes the suffix phox, which refers to phagocyte oxidase [10]. The one exception is gp91phox, which has also been named NADPH oxidase 2 (Nox2) [11].
10. Babior, B. M. (1991) The respiratory burst oxidase and the molecular basis of chronic granulomatous disease. Am. J. Hematol. 37, 263–266. 11. Lambeth, J. D., Cheng, G., Arnold, R. S., Edens, W. A. (2000) Novel homologs of gp91phox. Trends Biochem. Sci. 25, 459–461. |
The source is mentioned somewhere in the middle, but it is not clear to the reader that the entire passage is taken from it, including a reference to the literature. |
|
Letzte Bearbeitung dieser Seite: durch Benutzer:Graf Isolan, Zeitstempel: 20140226213657