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The determination of Q192R polymorphism of paraoxonase 1 by using non-toxic substrate p-nitrophenylacetate.

Mogarekar MR, Chawhan SS - Indian J Hum Genet (2013)

Bottom Line: It was found that paraoxonase activity is trimodally distributed in both the methods.There is no significant difference in the distribution of PON1 phenotypes of both reference method and new method being frequencies 0.946 and 0.376 respectively and there was no significant difference for phenotypic polymorphism for an individual by both methods (χ(2)= 0.15 and P = 0.9262).This method can be used for PON1 phenotype in different pathological and complex disease conditions.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry, SRTR Government Medical College, Ambajogai, Maharashtra, India.

ABSTRACT

Context: The human serum paraoxonase 1 (PON1) is calcium-dependent esterase and associates with the high density serum lipoproteins. PON1 plays a major role in oxidation of high density lipoprotein and low density lipoprotein and prevention of atherogenesis in coronary heart disease. PON1Q and R allele hydrolyses number of substrates like paraoxon (PO) (diethyl p-nitrophenyl phosphate) and phenylacetate.

Aims: The aim of the study is to the determination of Q192R polymorphism of PON1 by using non-toxic substrate p-nitrophenylacetate and compares it with the phenotype determined by using PO as substrate.

Materials and methods: The study group consists of 60 healthy normal patients. Paraoxonase activity was measured using the procedure described by Eckerson (Reference method) and for phenotyping; the ratio of hydrolysis of PO in the presence of 1 M NaCl (salt-stimulated PON1, SALT) to the hydrolysis of phenylacetate (PA) is calculated. In new method (Haagen et al.) arylesterase activity measured using p-nitrophenylacetate and for phenotyping arylesterase, the ratio of inhibition of enzymatic hydrolysis of p-nitrophenylacetate (substrate) by phenyl acetate to non-inhibited hydrolysis of p-nitrophenylacetate (inhibited arylesterase activity (IA-IA0)/non-inhibited arylesterase activity (NIA).

Results: It was found that paraoxonase activity is trimodally distributed in both the methods. There is no significant difference in the distribution of PON1 phenotypes of both reference method and new method being frequencies 0.946 and 0.376 respectively and there was no significant difference for phenotypic polymorphism for an individual by both methods (χ(2)= 0.15 and P = 0.9262).

Conclusion: The Q192R polymorphism of PON1 by using non-toxic substrate p-nitrophenylacetate showed trimodal distribution of QQ (homozygous), QR (heterozygous), and RR (homozygous) phenotype and it is comparable with reference method. This method can be used for PON1 phenotype in different pathological and complex disease conditions.

No MeSH data available.


Related in: MedlinePlus

Ratio of reference vs new method
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Figure 5: Ratio of reference vs new method

Mentions: In the Figure 1a and 2a, showing graph of the ratio of inhibited to non-inhibited arylesterase versus frequency of individuals, it shows the trimodal distribution of the study population with the two antimodes. According to these antimodes the study group is distributed into 21 individuals with QQ phenotype, 27 individuals with QR phenotype and 12 individuals with RR phenotype with allele frequency of allele-Q and allele-R being 0.575 and 0.425 respectively. In Figure 1b and 2b, showing graph of the ratio of salt stimulated paraoxonase activity to arylesterase activity versus frequency of individuals; it shows the trimodal division of the study population by the two antimodes. According to these antimodes the study group is distributed into 23 individuals with QQ phenotype, 26 individuals with QR phenotype and 11 individuals with RR phenotype with allele frequency of allele-Q and allele-R being 0.625 and 0.375 respectively. In both the methods phenotype distributions were comparable and also consistent with published reports of frequencies in Caucasians using a method based on PCR. In the Figure 3, shows graph of ratio of reference vs new method which separates 3 different phenotypes.


The determination of Q192R polymorphism of paraoxonase 1 by using non-toxic substrate p-nitrophenylacetate.

Mogarekar MR, Chawhan SS - Indian J Hum Genet (2013)

Ratio of reference vs new method
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3722633&req=5

Figure 5: Ratio of reference vs new method
Mentions: In the Figure 1a and 2a, showing graph of the ratio of inhibited to non-inhibited arylesterase versus frequency of individuals, it shows the trimodal distribution of the study population with the two antimodes. According to these antimodes the study group is distributed into 21 individuals with QQ phenotype, 27 individuals with QR phenotype and 12 individuals with RR phenotype with allele frequency of allele-Q and allele-R being 0.575 and 0.425 respectively. In Figure 1b and 2b, showing graph of the ratio of salt stimulated paraoxonase activity to arylesterase activity versus frequency of individuals; it shows the trimodal division of the study population by the two antimodes. According to these antimodes the study group is distributed into 23 individuals with QQ phenotype, 26 individuals with QR phenotype and 11 individuals with RR phenotype with allele frequency of allele-Q and allele-R being 0.625 and 0.375 respectively. In both the methods phenotype distributions were comparable and also consistent with published reports of frequencies in Caucasians using a method based on PCR. In the Figure 3, shows graph of ratio of reference vs new method which separates 3 different phenotypes.

Bottom Line: It was found that paraoxonase activity is trimodally distributed in both the methods.There is no significant difference in the distribution of PON1 phenotypes of both reference method and new method being frequencies 0.946 and 0.376 respectively and there was no significant difference for phenotypic polymorphism for an individual by both methods (χ(2)= 0.15 and P = 0.9262).This method can be used for PON1 phenotype in different pathological and complex disease conditions.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry, SRTR Government Medical College, Ambajogai, Maharashtra, India.

ABSTRACT

Context: The human serum paraoxonase 1 (PON1) is calcium-dependent esterase and associates with the high density serum lipoproteins. PON1 plays a major role in oxidation of high density lipoprotein and low density lipoprotein and prevention of atherogenesis in coronary heart disease. PON1Q and R allele hydrolyses number of substrates like paraoxon (PO) (diethyl p-nitrophenyl phosphate) and phenylacetate.

Aims: The aim of the study is to the determination of Q192R polymorphism of PON1 by using non-toxic substrate p-nitrophenylacetate and compares it with the phenotype determined by using PO as substrate.

Materials and methods: The study group consists of 60 healthy normal patients. Paraoxonase activity was measured using the procedure described by Eckerson (Reference method) and for phenotyping; the ratio of hydrolysis of PO in the presence of 1 M NaCl (salt-stimulated PON1, SALT) to the hydrolysis of phenylacetate (PA) is calculated. In new method (Haagen et al.) arylesterase activity measured using p-nitrophenylacetate and for phenotyping arylesterase, the ratio of inhibition of enzymatic hydrolysis of p-nitrophenylacetate (substrate) by phenyl acetate to non-inhibited hydrolysis of p-nitrophenylacetate (inhibited arylesterase activity (IA-IA0)/non-inhibited arylesterase activity (NIA).

Results: It was found that paraoxonase activity is trimodally distributed in both the methods. There is no significant difference in the distribution of PON1 phenotypes of both reference method and new method being frequencies 0.946 and 0.376 respectively and there was no significant difference for phenotypic polymorphism for an individual by both methods (χ(2)= 0.15 and P = 0.9262).

Conclusion: The Q192R polymorphism of PON1 by using non-toxic substrate p-nitrophenylacetate showed trimodal distribution of QQ (homozygous), QR (heterozygous), and RR (homozygous) phenotype and it is comparable with reference method. This method can be used for PON1 phenotype in different pathological and complex disease conditions.

No MeSH data available.


Related in: MedlinePlus