Session: Undergraduate Research Posters: Biochemistry:

DNA-based molecular beacons have been used to detect specific nucleic acid sequences. Although molecular beacons using a duplex stem are most common, there is increasing interest in other DNA architectures, such as guanine quadruplexes. A significant utility in using a quadruplex scaffold would be the incorporation of two distinct recognition domains that would enable the molecular beacon to respond to two different sequences, either individually or cooperatively. In this poster we describe our efforts to probe the folding and unfolding pathways and relative stability of intramolecular quadruplexes with long dual loops as a function of sequence and coordinating cation. In particular, we examine the relationship between the length of the quadruplex stem (3 vs. 4 guanine tetrads), the length of the relative lateral loops, and the presence of sodium or potassium as a coordinating cation. We have designed a series of 3G and 4G quadruplex-forming sequences and studied their folding and unfolding behavior via UV-Visible thermal denaturation. We will show the patterns in stability and folding behavior found from these studies. This data will refine future sensor design and contribute to the growing body of research illuminating sequence-related effects upon folding behavior in G-quadruplex systems.

Elizabeth G Larson

Undergraduate Researcher, Willamette University

Appearances