Alaabta

Waxyeellada Oxidative ee saldhigyada DNA-da waxay caadi ahaan keentaa samaynta purines oksaydhized, gaar ahaan 7,8-dihydro-8-oxoguanine (8-oxoG) iyo 7,8-dihydro-8-oxoadenine (8-oxoA), kii hore waa si fiican- dhaawaca mutagenic ee la yaqaan.Maadaama 8-oxoG ay si sahal ah ugu xiran tahay oksaydhyo dheeraad ah marka la barbar dhigo saldhigyada caadiga ah, gelinta saldhigga inta lagu jiro isku-darka DNA-da ee ka soo horjeeda qaabka oksaydhka ah ee 8-oxoG ayaa lagu baaray gudaha vitro.Qaab-dhismeedka synthetic oo ka kooban hal 8-oxoG nabar ah ayaa markii hore lagu daaweeyay oksijiin hal-elektarooni ah oo kala duwan ama xaaladaha oksijiinta hal-abuurka ah ka dibna waxaa la sammeeyay kordhinta asaasiga ah ee ay ka kooban tahay Klenow fragment exo- (Kf exo-), calf thymus DNA polymerase alpha (pol alpha). ) ama DNA polymerase beta (pol beta).Iyadoo la raacayo warbixinadii hore, dAMP iyo dCMP ayaa la geliyey si ka soo horjeeda 8-oxoG oo leh dhammaan saddexda polymerases DNA.Waxa xiisaha lihi leh, oksaydhaynta 8-oxoG ayaa la ogaaday in ay keento dAMP iyo galinta dGMP oo ka soo horjeeda nabarka Kf exo- oo leh xannibaad ku meel gaadh ah oo kordhinta asaasiga ah o ka dhacaya goobta saldhiga la beddelay.Intaa waxaa dheer, nabarku wuxuu ka kooban yahay xannibaad inta lagu jiro isku-darka DNA-da ee pol alfa iyo pol beta.Tijaabooyin leh 8-oxoA-modified template oligonucleotide waxay muujinayaan in labadaba 8-oxoA iyo qaab oksaydheysan oo ah 8-oxoA gelinta tooska ah ee dTMP ee Kf exo-.Falanqaynta spectrometric mass ee 8-oxoG-ka kooban oligonucleotides ka hor iyo ka dib oksaydhka leh IrCl62-waxay la jaan qaadayaan oksaydhka ugu horrayn goobta 8-oxoG, taasoo keentay samaynta unugyada guanidinohydantoin oo ah sheyga ugu weyn.Lama helin wax caddayn ah oo ku saabsan samaynta goobo aan sal lahayn.Natiijooyinkani waxay muujinayaan in qaabka oksaydhka ah ee 8-oxoG, laga yaabo in guanidinohydantoin, uu toosin karo akhrinta khaldan iyo khaladka dNTP-yada inta lagu jiro isku dhafka DNA.Haddii habkan oo kale uu ka dhacay vivo, waxay ka dhigan tahay dhibco mutagenic ah oo u horseedaya G->T iyo G--> C.Si kastaba ha ahaatee, qaabka oksaydhisku ee u dhigma ee 8-oxoA ayaa ugu horreyn muujinaya gelinta saxda ah ee T inta lagu jiro isku-darka DNA-da ee Kf exo-.