Abstract:
Gamma-H2Ax protein is seen at the DNA damage sites and it is also incorporated randomly in to the histones throughout the DNA, which produce other necessary components for the DNA repair. It also contributes to the stable nucleosome formation when the histone molecules wrap the DNA. The histone complexes comprise of proteins called H2A ,H2B, H3 and H4. The H2A protein family further contains the highest number of variants, which are H2A1, H2A2, H2AX and H2AZ. This protein has a unique carboxyl tail which consist of a conserved reactive site of one serine residue at the position 139. H2Ax becomes phosphorylated at Serine 139, which is 4 residues from the C-terminus, in the presence of DNA damage. Gamma-H2Ax is further acetylated at Lys 5 and ubiquitinated on Lys 119. Graphene quantum dots (GQDs) have a size less than 10nm and they are about 1-10 of layers of graphene, which are used in the various biomedical applications. Some of their important properties include chemical stability and quantum confinement effect. In this study we investigate the effects of the different sizes of GQDs as they interact with H2AX to form a molecular basis of isolating different protein biomarkers based on their molecular weight.