ALDEHYDE OXIDASE GENERATES DEOXYRIBONUCLEIC-ACID SINGLE-STRAND NICKS IN-VITRO

We purified aldehyde oxidase (AO) from rabbit livers and found that AO produced deoxyribonucleic acid (DNA) single strand nicks in vitro, Ac etaldehyde, benzaldehyde, and certain purine bases were effective subs trates for AO catalyzed DNA strand nicking, DNA strand nicking did not occur with the reducing substrates nicotinamideadenine dinucleotide o r dithionite that produce superoxide anion (O-2(.-)), Inclusion of ele ctron transport inhibitors, potassium cyanide, ferricyanide or menadio ne, prevented AO catalyzed nicking, AO induced DNA strand nicking was dependent upon hydrogen peroxide (H2O2) formation and mast likely gene ration of hydroxyl radical (HO.). The present observations may be pert inent to the recently proposed involvement of AO in inherited juvenile familial amyotrophic lateral sclerosis (JFALS) and other oxygen radic al mediated diseases.