Poster abstracts
Poster number 131 submitted by Supuni Thalalla Gamage
Electrostatics of rRNA Hairpins as Determined by Platination Kinetics
Gayani Dedduwa-Mudalige, Supuni Thalalla Gamage, Christine S Chow
Abstract:
Electrostatics play an important role in RNA-ligand interactions. Positively charged drug
molecules and other ligands are attracted to the negatively charged RNA. Monovalent
and divalent ions affect the electrostatic properties and influence these interactions;
however, studying these properties experimentally in solution can be challenging. This
work focuses on the use of transition metal complexes as tools to study the electrostatic
microenvironment, as well as global electrostatics, of RNA. More specifically, positively
charged monoaquated cisplatin and small model ribosomal RNA (rRNA) constructs are
employed. The rates of the platination are determined by using gel shift analysis, and the
electrostatic properties of rRNA are determined from the kinetics of platinum
coordination under varying salt conditions. The rate of platination with RNA is shown to
decrease in the presence of divalent cations. Furthermore, rRNA shows different
electrostatic properties in the presence of monovalent and divalent cations. Overall, the
present work demonstrates the utility of monoaquated cisplatin kinetics as a tool to
compare electrostatic environments of different RNA constructs with varying sequences,
secondary and tertiary structures, or nucleotide modification levels.
Keywords: