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Chicken antibodies as a tool of cytochrome P450 immunodetection
Mácová, Iva ; Hodek, Petr (advisor) ; Koblas, Tomáš (referee)
Cytochrome P450 is an important enzyme which catalyzes a large amount of reactions of endogenous and exogenous metabolism. There are compounds which increase expression of this enzyme and it leads up to the carcinogen activation and cancer formation. It includes much propagated chemopreventive compounds which are consumed abundantly in dietary supplements. It is therefore important to have the methods for determination of cytochrome P450 induction. One of these methods is the cytochrome P450 immunodetection by Western blotting. The detection of proteins on the membrane is done by the specific antibodies mostly gained from mammals. In this bachelor thesis there is the evidence that the antibodies from hen egg serve as well as the mammalian antibodies. The cytochromes P450 1A1 and 1A2 was detected by these egg antibodies after rat exposure to the model chemopreventive compounds β-naphthoflavone.
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Preparation and characterization of antipeptide antibodies for immunodetection of cytochromes P450
Mácová, Iva ; Hodek, Petr (advisor) ; Koblas, Tomáš (referee)
The cytochromes P450 are enzymes participating in metabolism of endogenous and exogenous compounds. Their substrates include also carcinogens which may initiate carcinogenesis after activation by CYP450. Inductors of these enzymes are also chemopreventive compounds which are very popular and recommended in current time. Thus, studying of the effect of the chemopreventive compounds on cytochromes P450 induction and cancer development is of a high clinical importance. The CYPs are most commonly found in the liver. However, there are forms that have not been detected in any human healthy tissue but their overexpression was observed in tumors. For this reason, they could serve for diagnosis and prognosis of cancer. Among these cytochromes are CYP2S1 and 2W1 which can be prognostic markers of colorectal cancer. Therefore, it would be opportune to have some tools for these enzyme detection. One option is immunodetection of cytochromes P450 by Western blot using the specific antibodies. Today mammalian antibodies (IgG) are the most widely used but antibodies isolated from egg yolk (IgY) become popular mainly due to the large number of undisputed advantages. For the preparation of the peptide immunogen, suitable peptide sequences were selected from CYP2S1 and 2W1 primary structure. The synthesized peptides...
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Study on the interaction of chemopreventive compounds and food born carcinogens with cytochrome P450 enzymes
Brabencová, Eliška ; Hodek, Petr (advisor) ; Koblihová, Jitka (referee)
The use of food supplements containing natural chemopreventive compounds increased in recent years. Some of the most popular chemopreventive compounds are flavonoids. Due to their natural origin, flavonoids are generally accepted as safe compounds. They exert antioxidant, anti-cancer and anti-inflammatory properties. However, flavonoids should be considered as foreign compounds (xenobiotics). Flavonoids interact with many enzymes, among the most important belong cytochromes P450 (CYPs), key enzymes of the first phase of biotransformation of xenobiotics (e.g. drugs, carcinogens). CYPs catalyze reactions leading mainly to detoxification of xenobiotics. However, some CYPs are involved in the activation of carcinogens, particularly CYP1A1 and CYP1A2 activate e.g. heterocyclic amines. Flavonoids might enhance the activation of carcinogens via induction of these CYPs or stimulation of their activities and hence, increase the risk of a cancer development. The thesis is focused on the influence of flavonoids and food carcinogens on the induction and activity of CYP1A1 and CYP1A2 in liver and small intestine of rats. For the purpose of this study, the small intestine was dissected into three parts: proximal (nearest to stomach), middle and distal. Western blotting was used for the evaluation of CYP...
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Preparation and characterization of antipeptide antibodies for immunodetection of cytochromes P450
Mácová, Iva ; Hodek, Petr (advisor) ; Koblas, Tomáš (referee)
The cytochromes P450 are enzymes participating in metabolism of endogenous and exogenous compounds. Their substrates include also carcinogens which may initiate carcinogenesis after activation by CYP450. Inductors of these enzymes are also chemopreventive compounds which are very popular and recommended in current time. Thus, studying of the effect of the chemopreventive compounds on cytochromes P450 induction and cancer development is of a high clinical importance. The CYPs are most commonly found in the liver. However, there are forms that have not been detected in any human healthy tissue but their overexpression was observed in tumors. For this reason, they could serve for diagnosis and prognosis of cancer. Among these cytochromes are CYP2S1 and 2W1 which can be prognostic markers of colorectal cancer. Therefore, it would be opportune to have some tools for these enzyme detection. One option is immunodetection of cytochromes P450 by Western blot using the specific antibodies. Today mammalian antibodies (IgG) are the most widely used but antibodies isolated from egg yolk (IgY) become popular mainly due to the large number of undisputed advantages. For the preparation of the peptide immunogen, suitable peptide sequences were selected from CYP2S1 and 2W1 primary structure. The synthesized peptides...
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|
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Chicken antibodies as a tool of cytochrome P450 immunodetection
Mácová, Iva ; Hodek, Petr (advisor) ; Koblas, Tomáš (referee)
Cytochrome P450 is an important enzyme which catalyzes a large amount of reactions of endogenous and exogenous metabolism. There are compounds which increase expression of this enzyme and it leads up to the carcinogen activation and cancer formation. It includes much propagated chemopreventive compounds which are consumed abundantly in dietary supplements. It is therefore important to have the methods for determination of cytochrome P450 induction. One of these methods is the cytochrome P450 immunodetection by Western blotting. The detection of proteins on the membrane is done by the specific antibodies mostly gained from mammals. In this bachelor thesis there is the evidence that the antibodies from hen egg serve as well as the mammalian antibodies. The cytochromes P450 1A1 and 1A2 was detected by these egg antibodies after rat exposure to the model chemopreventive compounds β-naphthoflavone.
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