Format

Send to

Choose Destination
See comment in PubMed Commons below
J Atheroscler Thromb. 2003;10(6):337-42.

The ratio of serum paraoxonase/arylesterase activity using an improved assay for arylesterase activity to discriminate PON1(R192) from PON1(Q192).

Author information

1
Department of Clinical Pathology, Hyogo College of Medicine, Hyogo, Japan. m-nakanishi@mail.falco.or.jp

Abstract

Human serum paraoxonase (PON1) exists in 2 major polymorphic forms: Q (glutamine) or R (arginine) at codon 192. The PON1(192) activity polymorphism is substrate dependent. The PON1(Q192) isoform has a higher rate of in vitro hydrolysis of diazoxon, sarin, and soman, whereas the PON1(R192) isoform has higher activity for the hydrolysis of paraoxon and chlorpyrifos oxon. Both isoforms hydrolyze phenyl acetate at approximately the same rate. The present study described and evaluated a kinetic method of arylesterase activity determination with a modified fixed incubation method that used the oxidative coupling of phenol with 4-aminoantipyrine of phenyl acetate as the substrate. Our improved method shows that arylesterase activity is lower with the PON1(R192) isoform than with the PON1(Q192) isoform. The average activities of serum of individuals of a specific PON1(Q192) genotype showed higher arylesterase and lower paraoxonase activity than the PON1(R192) genotype. The ratio of paraoxonase/arylesterase activity showed a clear separation of all three PON1(192) genotypes with no overlap between the groups (QQ: < 5.0, QR: 5.0-11.0, RR: > 11.0). PCR has suggested that the PON1(192) phenotypes correspond to the PON1(192) genotypes. Therefore, when conducting epidemiological or mechanistic studies that examine the role of PON1 in organophosphorus or lipid metabolism, this ratio is more useful and informative than a PCR-based genotype alone.

PMID:
15037822
[Indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for J-STAGE, Japan Science and Technology Information Aggregator, Electronic
    Loading ...
    Support Center