Biology subjects

Westberg, M.

Publications and source records attributed to Westberg, M..

2 recordsLinked to original sources

bioRxiv2020

A red fluorescent protein with improved monomericity enables ratiometric voltage imaging with ASAP3

A ratiometric genetically encoded voltage indicator (GEVI) would be desirable for tracking transmembrane voltage changes in cells that are undergoing motion. To create a high-performance ratiometric GEVI, we explored the possibility of adding a voltage-independent red fluorophore to ASAP3, a high-gain green fluorescent GEVI. We performed combinatorial multi-site mutagenesis on the cyan-excitable red fluorescent protein mCyRFP1 to enhance brightness and monomericity, creating mCyRFP3. Among red fluorescent proteins tested, mCyRFP3 proved to be the least perturbing when fused to ASAP3. We demonstrate that the red fluorescence of ASAP3-mCyRFP3 (ASAP3-R3) provides an effective reference channel to remove motion artifacts from voltage-induced changes in green fluorescence. Finally we use ASAP3-R3 to visualize membrane voltage changes throughout the cell cycle of motile cells.

cell biology↗

bioRxiv2020

Rational design of a new class of protease inhibitors for the potential treatment of coronavirus diseases

The coronavirus main protease, Mpro, is a key protein in the virus life cycle and a major drug target. Based on crystal structures of SARSCoV2 Mpro complexed with peptidomimetic inhibitors, we recognized a binding characteristic shared with proline-containing inhibitors of hepatitis C virus protease. Initial tests showed that this subclass of HCV protease inhibitors indeed exhibited activity against Mpro. Postulating a benefit for a preorganized backbone conformation, we designed new ketoamide-based Mpro inhibitors based on central proline rings. One of the designed compounds, ML1000, inhibits Mpro with low-nanomolar affinity and suppresses SARSCoV2 viral replication in human cells at sub-micromolar concentrations. Our findings identify ML1000 as a promising new pre-organized scaffold for the development of anti-coronavirus drugs.

biochemistry↗