Differences in biological activities between recombinant human paraoxonase 1 (rhPON1) subtype isozemys R/Q as antidotes against organophosphorus poisonings.

Paraoxonase 1 (PON1) is a type of aromatic esterase widely existing in mammals. It can hydrolyze various kinds of compounds effectively in vivo and in vitro. Previous studies have confirmed that PON1 can be used as antidote against organophosphorus poisonings (OPs). In this study, we obtained two subtype isozymes (i.e. rhPON1 and rhPON1) by gene recombination and compared their detoxification effects against different OPs in rats. The rhPON1 demonstrated better detoxification effect against chlorpyrifos poisoning than the rhPON1, whose detoxification effect against diazinon poisoning was prior to the former. Both of them showed poor detoxification effect against trithion. Therefore, we concluded that, to different OPs, better detoxification effect may be achieved by selecting the PON1 subtype isozyme with higher specific hydrolytic activity.