The optical biosensor study of the redox partner interaction with the cytochrome P450 2B4-containing monooxygenase system under hydroxylation conditions

Using chicken antibodies IgY (purified from egg yolks) against mammalian cytochromes P450 and by means of cytochrome P450 marker substrates, we found for the first time the presence of hepatopancreatic cytochrome P450 in crayfishOrconectes limosus(an inducible cytochrome P450 2B-like enzyme) and we were able to detect and quantify cytochrome P450 1A1 in microsomes of human livers. Expression levels of cytochrome P450 1A1 in human livers constituted less than 0.6% of the total hepatic cytochrome P450 complement. The results obtained in our study are clear examples that chicken IgY are suitable for cytochrome P450 detection and quantification. Due to the evolutionary distance, chicken IgY reacts with more epitopes on a mammalian antigen, which gives an amplification of the signal. Moreover, this approach offers many advantages over common mammalian antibody production since chicken egg is an abundant source of antibodies (about 100 mg IgY/yolk) and the egg collection is a non-invasive technique. In the case of antibodies against cytochrome P450 2B4, we documented fast and steady production of highly specific immunoglobulins. Thus, chicken antibodies should be considered as a good alternative to and/or superior substitute for conventional polyclonal antibody produced in mammals.

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Human Lanosterol 14-Alpha Demethylase (CYP51A1) Is a Putative Target for Natural Flavonoid Luteolin 7,3′-Disulfate

Molecules ◽

10.3390/molecules26082237 ◽

2021 ◽

Vol 26 (8) ◽

pp. 2237

Author(s):

Leonid Kaluzhskiy ◽

Pavel Ershov ◽

Evgeniy Yablokov ◽

Tatsiana Shkel ◽

Irina Grabovec ◽

...

Keyword(s):

Cholesterol Metabolism ◽

Cholesterol Biosynthesis ◽

Clinical Importance ◽

Optical Biosensor ◽

Water Soluble ◽

Soluble Form ◽

Redox Partner ◽

Access Channel ◽

Kd Values ◽

Key Steps

Widespread pathologies such as atherosclerosis, metabolic syndrome and cancer are associated with dysregulation of sterol biosynthesis and metabolism. Cholesterol modulates the signaling pathways of neoplastic transformation and tumor progression. Lanosterol 14-alpha demethylase (cytochrome P450(51), CYP51A1) catalyzes one of the key steps in cholesterol biosynthesis. The fairly low somatic mutation frequency of CYP51A1, its druggability, as well as the possibility of interfering with cholesterol metabolism in cancer cells collectively suggest the clinical importance of CYP51A1. Here, we show that the natural flavonoid, luteolin 7,3′-disulfate, inhibits CYP51A1 activity. We also screened baicalein and luteolin, known to have antitumor activities and low toxicity, for their ability to interact with CYP51A1. The Kd values were estimated using both a surface plasmon resonance optical biosensor and spectral titration assays. Unexpectedly, in the enzymatic activity assays, only the water-soluble form of luteolin—luteolin 7,3′-disulfate—showed the ability to potently inhibit CYP51A1. Based on molecular docking, luteolin 7,3′-disulfate binding suggests blocking of the substrate access channel. However, an alternative site on the proximal surface where the redox partner binds cannot be excluded. Overall, flavonoids have the potential to inhibit the activity of human CYP51A1 and should be further explored for their cholesterol-lowering and anti-cancer activity.

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