| Autor: |
Glenn IS; Department of Pharmaceutical Chemistry, University of California San Francisco (UCSF), San Francisco, California 94143, United States., Hall LN; Department of Pharmaceutical Chemistry, University of California San Francisco (UCSF), San Francisco, California 94143, United States., Khalid MM; Gladstone Institutes, San Francisco, California 94158, United States.; Department of Medicine, University of California, San Francisco, San Francisco, California 94158, United States., Ott M; Gladstone Institutes, San Francisco, California 94158, United States.; Department of Medicine, University of California, San Francisco, San Francisco, California 94158, United States.; Chan Zuckerberg Biohub, San Francisco, California 94158, United States., Shoichet BK; Department of Pharmaceutical Chemistry, University of California San Francisco (UCSF), San Francisco, California 94143, United States. |
| Abstrakt: |
Colloidal aggregation is one of the largest contributors to false positives in early drug discovery. Here, we consider aggregation's role in cell-based infectivity assays in Covid-19 drug repurposing. We investigated the potential aggregation of 41 drug candidates reported as SARs-CoV-2 entry inhibitors. Of these, 17 formed colloidal particles by dynamic light scattering and exhibited detergent-dependent enzyme inhibition. To evaluate the impact of aggregation on antiviral efficacy in cells, we presaturated the colloidal drug suspensions with BSA or spun them down by centrifugation and measured the effects on spike pseudovirus infectivity. Antiviral potencies diminished by at least 10-fold following both BSA and centrifugation treatments, supporting a colloid-based mechanism. Aggregates induced puncta of the labeled spike protein in fluorescence microscopy, consistent with sequestration of the protein on the colloidal particles. These observations suggest that colloidal aggregation is common among cell-based antiviral drug repurposing and offers rapid counter-screens to detect and eliminate these artifacts. |
