Impeded repair of abasic site damaged lesions in DNA adsorbed over functionalized multiwalled carbon nanotube and graphene oxide.
The processing of abasic site DNA damage lesions in extracellular DNA in the presence of engineered carbon nanomaterials (CNMs) is demonstrated. The efficacy of the apurinic-apyrimidinic endonuclease 1 (APE1) in the cleavage of abasic site lesions in the presence of carboxylated multi-walled carbon nanotubes (MWCNT-COOH) and graphene oxide (GO) are compared. The CNMs were found to perturb the incision activity of APE1. The reason for such perturbation process was anticipated to take place either by the non-specific adsorption of APE1 over the free surface of the CNMs or steric hindrance offered by the CNM-DNA complex. Accordingly, bovine serum albumin (BSA) was selectively utilized to block the free surface of the CNM-DNA hybrid material. Further treatment of the CNM-DNA-BSA complex with APE1 resulted in a marginal increase in APE1 efficiency. This indicates that APE1 in solution is unable to process the abasic sites on DNA adsorbed over the CNMs. However, the cleavage activity of APE1 was restored in the presence of non-ionic surfactant (Tween 20) that inhibits adsorption of the DNA on the surface of the CNMs. The conformational deformation of the DNA, along with steric hindrance induced by the CNMs resulted in the inhibition of abasic site DNA repair by APE1. Moreover, appreciable changes in the secondary structure of APE1 adsorbed over the CNMs were observed that contribute further to the repair refractivity of the abasic sites. From a toxicological viewpoint, these findings can be extended to the study of the effect of engineered nanoparticles in the intracellular DNA repair process.
Department of Chemistry, IIT Patna, Patna 801103, India.
Rina
R
Kumari
Department of Chemistry, IIT Patna, Patna 801103, India; Rubber Technology Centre, IIT Kharagpur, Kharagpur 721302, India.
Titash
T
Mondal
Rubber Technology Centre, IIT Kharagpur, Kharagpur 721302, India. Electronic address: anilkb@rtc.iitkgp.ernet.in.
Anil K
AK
Bhowmick
Department of Chemistry, IIT Patna, Patna 801103, India. Electronic address: prolay@iitp.ac.in.
Prolay
P
Das
D004249:DNA Damage / Q000235:genetics; D004260:DNA Repair / Q000235:genetics; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase / Q000378:metabolism; D006108:Graphite / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*
D037742:Nanotubes, Carbon; D006108:Graphite; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase
APE1; Abasic site; Carbon nanomaterial; Graphene oxide; Multiwalled carbon nanotubes