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Membrane phospholipid augments cytochrome P4501a enzymatic activity by modulating structural conformation during detoxification of xenobiotics.

Ghosh MC, Ray AK - PLoS ONE (2013)

Bottom Line: Cytochrome P450 is a superfamily of membrane-bound hemoprotein that gets involved with the degradation of xenobiotics and internal metabolites.In this present investigation, we observed that treating catfish with carbofuran augmented total phospholipid in the liver.We purified the carbofuran-induced cytochrome P4501A protein from catfish liver.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America. ghosh.manik7@gmail.com

ABSTRACT
Cytochrome P450 is a superfamily of membrane-bound hemoprotein that gets involved with the degradation of xenobiotics and internal metabolites. Accumulated body of evidence indicates that phospholipids play a crucial role in determining the enzymatic activity of cytochrome P450 in the microenvironment by modulating its structure during detoxification; however, the structure-function relationship of cytochrome P4501A, a family of enzymes responsible for degrading lipophilic aromatic hydrocarbons, is still not well defined. Inducibility of cytochrome P4501A in cultured catfish hepatocytes in response to carbofuran, a widely used pesticide around the world, was studied earlier in our laboratory. In this present investigation, we observed that treating catfish with carbofuran augmented total phospholipid in the liver. We examined the role of phospholipid on the of cytochrome P4501A-marker enzyme which is known as ethoxyresorufin-O-deethylase (EROD) in the context of structure and function. We purified the carbofuran-induced cytochrome P4501A protein from catfish liver. Subsequently, we examined the enzymatic activity of purified P4501A protein in the presence of phospholipid, and studied how the structure of purified protein was influenced in the phospholipid environment. Membrane phospholipid appeared to accelerate the enzymatic activity of EROD by changing its structural conformation and thus controlling the detoxification of xenobiotics. Our study revealed the missing link of how the cytochrome P450 restores its enzymatic activity by changing its structural conformation in the phospholipid microenvironment.

Show MeSH
Treatment with carbofuran increased phospholipid in catfish livers.Injection of carbofuran and extraction of liver from catfish were performed according to ‘Materials and methods’. Total lipid was isolated from membrane fraction of liver, and phospholipid was estimated from total lipid. * indicates that the value is statistically significant, at p<0.05.
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pone-0057919-g001: Treatment with carbofuran increased phospholipid in catfish livers.Injection of carbofuran and extraction of liver from catfish were performed according to ‘Materials and methods’. Total lipid was isolated from membrane fraction of liver, and phospholipid was estimated from total lipid. * indicates that the value is statistically significant, at p<0.05.

Mentions: Upon treatment with carbofuran, the amount of total phospholipid increased significantly in the liver compared to vehicle-treated fish (Fig. 1). Phospholipid has been used to reconstitute the enzymatic activity of different purified P450 proteins, including P4501A and P4503A [32], [33], [34], but an intriguing question remains: How does increased phospholipid influence enzymatic activity of P4501A? Based upon the light of research of Agarwal et al., it can be conceivable that phospholipid may alter the structural conformation of purified protein which in turn augments the enzymatic activity.


Membrane phospholipid augments cytochrome P4501a enzymatic activity by modulating structural conformation during detoxification of xenobiotics.

Ghosh MC, Ray AK - PLoS ONE (2013)

Treatment with carbofuran increased phospholipid in catfish livers.Injection of carbofuran and extraction of liver from catfish were performed according to ‘Materials and methods’. Total lipid was isolated from membrane fraction of liver, and phospholipid was estimated from total lipid. * indicates that the value is statistically significant, at p<0.05.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3585281&req=5

pone-0057919-g001: Treatment with carbofuran increased phospholipid in catfish livers.Injection of carbofuran and extraction of liver from catfish were performed according to ‘Materials and methods’. Total lipid was isolated from membrane fraction of liver, and phospholipid was estimated from total lipid. * indicates that the value is statistically significant, at p<0.05.
Mentions: Upon treatment with carbofuran, the amount of total phospholipid increased significantly in the liver compared to vehicle-treated fish (Fig. 1). Phospholipid has been used to reconstitute the enzymatic activity of different purified P450 proteins, including P4501A and P4503A [32], [33], [34], but an intriguing question remains: How does increased phospholipid influence enzymatic activity of P4501A? Based upon the light of research of Agarwal et al., it can be conceivable that phospholipid may alter the structural conformation of purified protein which in turn augments the enzymatic activity.

Bottom Line: Cytochrome P450 is a superfamily of membrane-bound hemoprotein that gets involved with the degradation of xenobiotics and internal metabolites.In this present investigation, we observed that treating catfish with carbofuran augmented total phospholipid in the liver.We purified the carbofuran-induced cytochrome P4501A protein from catfish liver.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America. ghosh.manik7@gmail.com

ABSTRACT
Cytochrome P450 is a superfamily of membrane-bound hemoprotein that gets involved with the degradation of xenobiotics and internal metabolites. Accumulated body of evidence indicates that phospholipids play a crucial role in determining the enzymatic activity of cytochrome P450 in the microenvironment by modulating its structure during detoxification; however, the structure-function relationship of cytochrome P4501A, a family of enzymes responsible for degrading lipophilic aromatic hydrocarbons, is still not well defined. Inducibility of cytochrome P4501A in cultured catfish hepatocytes in response to carbofuran, a widely used pesticide around the world, was studied earlier in our laboratory. In this present investigation, we observed that treating catfish with carbofuran augmented total phospholipid in the liver. We examined the role of phospholipid on the of cytochrome P4501A-marker enzyme which is known as ethoxyresorufin-O-deethylase (EROD) in the context of structure and function. We purified the carbofuran-induced cytochrome P4501A protein from catfish liver. Subsequently, we examined the enzymatic activity of purified P4501A protein in the presence of phospholipid, and studied how the structure of purified protein was influenced in the phospholipid environment. Membrane phospholipid appeared to accelerate the enzymatic activity of EROD by changing its structural conformation and thus controlling the detoxification of xenobiotics. Our study revealed the missing link of how the cytochrome P450 restores its enzymatic activity by changing its structural conformation in the phospholipid microenvironment.

Show MeSH