Inhibitors of SARS-CoV entry--identification using an internally-controlled dual envelope pseudovirion assay.

Severe acute respiratory syndrome-associated coronavirus (SARS-CoV) emerged as the causal agent of an endemic atypical pneumonia, infecting thousands of people worldwide. Although a number of promising potential vaccines and therapeutic agents for SARS-CoV have been described, no effective antiviral drug against SARS-CoV is currently available. The intricate, sequential nature of the viral entry process provides multiple valid targets for drug development. Here, we describe a rapid and safe cell-based high-throughput screening system, dual envelope pseudovirion (DEP) assay, for specifically screening inhibitors of viral entry. The assay system employs a novel dual envelope strategy, using lentiviral pseudovirions as targets whose entry is driven by the SARS-CoV Spike glycoprotein. A second, unrelated viral envelope is used as an internal control to reduce the number of false positives. As an example of the power of this assay a class of inhibitors is reported with the potential to inhibit SARS-CoV at two steps of the replication cycle, viral entry and particle assembly. This assay system can be easily adapted to screen entry inhibitors against other viruses with the careful selection of matching partner virus envelopes

Setup and characterization of a hollow core fiber waveguide for transient absorption experiments with short wavelength infrared pulses

An apparatus has been set up and aligned within the scope of this thesis that allows for ultrashort laser pulses with a central wavelength between 1300 and 1550 nm to propagate through a flexible hollow-core fiber. This work describes the setup and alignment process including the measurement of crucial laser parameters like focus and intensity as well as spectrum. Subsequently a full pulse characterization of the induced pulses was carried out using the TG-FROG method. For this purpose the pulses were measured before as well as after the fiber. The setup enables the possibility for spectral broadening of the transmitted pulses. For this purpose the fiber was filled with Helium gas at different pressures and the FROG retrievals were compared with the previous results. With this apparatus an extensive of control is gained over the pulses extending their scope of use in attosecond transient absorption spectroscopy for atomic and molecular dynamics investigations