Biology subjects

Lutz, W. E.

Publications and source records attributed to Lutz, W. E..

3 recordsLinked to original sources

bioRxiv2021

Bacterial expression and purification of functional recombinant SARS-CoV-2 spike receptor binding domain

The COVID-19 pandemic caused by SARS-CoV-2 has applied significant pressure on overtaxed healthcare around the world, underscoring the urgent need for rapid diagnosis and treatment. We have developed a bacterial strategy for the expression and purification of the SARS-CoV-2 spike protein receptor binding domain using the CyDisCo system to create and maintain the correct disulfide bonds for protein integrity and functionality. We show that it is possible to quickly and inexpensively produce functional, active antigen in bacteria capable of recognizing and binding to the ACE2 (angiotensin-converting enzyme) receptor as well as antibodies in COVID-19 patient sera.

biochemistry↗

bioRxiv2020

Direct detection of coupled proton and electron transfers in human manganese superoxide dismutase

Human manganese superoxide dismutase (MnSOD) is a critical oxidoreductase found in the mitochondrial matrix. Concerted proton and electron transfers (CPETs) are used by the enzyme to rid the mitochondria of O2 *-, a precursor to other harmful reactive oxygen and nitrogen species. The mechanisms of CPET-utilizing enzymes are typically unknown due to the difficulties in detecting the protonation states of specific residues and solvent molecules involved in catalysis while controlling the redox state of the enzyme. Here, neutron diffraction of redox-controlled MnSOD crystals revealed the all-atom structures of Mn3+SOD and Mn2+SOD delivering unique data on sites that change protonation state. A novel mechanism is proposed from the direct observation of glutamine deprotonation, the involvement of Tyr and His with altered pKas, and four unusual strong-short hydrogen bonds, including a low barrier hydrogen bond, that change with the oxidation state of the metal. Quantum calculations provide insight into the electronic modulation of the observed structures and the enzymatic mechanism.

biochemistry↗

bioRxiv2020

Bromelain Inhibits SARS-CoV-2 Infection in VeroE6 Cells

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). The initial interaction between Transmembrane Serine Protease 2 (TMPRSS2) primed SARS-CoV-2 spike (S) protein and host cell receptor angiotensin-converting enzyme 2 (ACE-2) is a pre-requisite step for this novel coronavirus pathogenesis. Here, we expressed a GFP-tagged SARS-CoV-2 S-Ectodomain in Tni insect cells. That contained sialic acid-enriched N- and O-glycans. Surface resonance plasmon (SPR) and Luminex assay showed that the purified S-Ectodomain binding to human ACE-2 and immunoreactivity with COVID-19 positive samples. We demonstrate that bromelain (isolated from pineapple stem and used as a dietary supplement) treatment diminishes the expression of ACE-2 and TMPRSS2 in VeroE6 cells and dramatically lowers the expression of S-Ectodomain. Importantly, bromelain treatment reduced the interaction between S-Ectodomain and VeroE6 cells. Most importantly, bromelain treatment significantly diminished the SARS-CoV-2 infection in VeroE6 cells. Altogether, our results suggest that bromelain or bromelain rich pineapple stem may be used as an antiviral against COVID-19. Highlights O_FIG O_LINKSMALLFIG WIDTH=178 HEIGHT=200 SRC="FIGDIR/small/297366v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@b7afb0org.highwire.dtl.DTLVardef@16f8185org.highwire.dtl.DTLVardef@1a07df8org.highwire.dtl.DTLVardef@1ae33fa_HPS_FORMAT_FIGEXP M_FIG C_FIG O_LIBromelain inhibits / cleaves the expression of ACE-2 and TMPRSS2 C_LIO_LIBromelain cleaves / degrades SARS-CoV-2 spike protein C_LIO_LIBromelain inhibits S-Ectodomain binding and SARS-CoV-2 infection C_LI

microbiology↗