The study of the terahertz absorption spectrum of G-Quadruplex

The secondary structures of nucleic acids are crucial to the regulation of genomic activities, and could potentially serve as a marker for some cancers. Question remains whether such structures could have distinct absorption features in the terahertz range, including a 1.6 THz peak absorption previously reported in methylated DNA. In this study, we examine the terahertz absorption spectrum of G-quadruplex (G4), a key secondary DNA structure that has been closely linked to cancer. The results show that in its most basic form, made up of self-assembled guanosine monophosphate (GMP), there are no distinct features. This result provides a reference for our ongoing investigation on other secondary structures of nucleic acids, and suggests that abnormal population of G4, as found in some cancers, may not be detectable via terahertz absorption spectroscopy.