Capillary Electrophoresis for Separation of Biomolecules and Viruses

Title: Capillary Electrophoresis for Separation of Biomolecules and Viruses
Authors: Gargaun, Ana
Date: 2016
Abstract: This thesis examines the use of capillary electrophoresis for the study of several biomolecules and their interactions and viruses. The first two experimental chapters focus on its utility for thermodynamic and kinetic analysis of molecules. Chapter one focuses on the use of non-equilibrium capillary electrophoresis of equilibrium mixtures (NECEEM), to calculate the dissociation constant for the interaction between double stranded microRNA-122 and protein p19. NECEEM was used to calculate the rate constants (koff = 0.059 ± 0.013 s-1, kon = 0.0022 ± 0.0008 s-1M-1) and the dissociation constant between miR-122 and wild type p19 (Kd = 27 ± 9 nM). A new method was developed to calculate the rate constant koff, by using multiple electric fields; which resulted in a koff value of 0.072 ± 0.022 s-1. In chapter two, the dissociation constant, Kd, was determined between HIV trans-activation response element and nuclear protein TOE1. It was demonstrated that TOE1, more specifically peptides ER19 and ED35, were binding to TAR with Kd values of 4.08 ± 0.19 µM for ER19 and 7.43 ± 1.60 µM for ED35. The discovery of the peptides’ inhibitory action of viral replication at the transcription level is a significant step towards further elucidating mechanisms for host response to HIV-1 infection. The third chapter focuses on the use of capillary electrophoresis for studying vesicular stomatitis virus (VSV) and vaccinia virus (VV). A new method was developed for quantification of VSV, using dithiothreitol. Furthermore, CE was used to study the preservation of VSV by a previously selected aptamer construct (quadramer) during freeze-thaw cycles. It was found that the infectivity of quadramer and aptamer pool-protected virus was higher than pure virus after 60 freeze−thaw cycles. It was also found that adding quadramers to the virus without freezing (cycle 0) increased the virus infectivity by 30%. We also investigated the potency of a carbohydrate-based ice recrystallization inhibitor, N-octyl-D-gluconamide (NOGlc) for its ability to eliminate the cold chain and stabilize the potency of VV. Viral potency after storage at room temperature demonstrated that NOGlc conserved the infectivity of VV, during 40 days.
CollectionThèses, 2011 - // Theses, 2011 -