Biology subjects

Werner, N.

Publications and source records attributed to Werner, N..

4 recordsLinked to original sources

bioRxiv2024

AZIN2-dependent polyamine metabolism determines adipocyte progenitor fate and protects against obesity and dysmetabolism

Adipose tissue homeostasis plays a critical role in metabolic disease but the metabolic circuitry regulating adipose tissue dynamics remains unclear. In this study, polyamine metabolism emerges as an important regulator of adipose tissue pathophysiology. We identify AZIN2 (Antizyme inhibitor 2), a protein promoting polyamine synthesis and acetylation, as a major regulator of total acetyl-CoA in adipocyte progenitors (APs). AZIN2 deficient APs demonstrate increased H3K27 acetylation marks in genes related to lipid metabolism, cell cycle arrest and cellular senescence, and enhanced adipogenesis compared to wild-type counterparts. Upon high-fat diet (HFD)-induced obesity, global AZIN2 deficiency in mice provokes adipose tissue hypertrophy, AP senescence, lipid storage perturbations, inflammation and insulin resistance. IL4 promotes Azin2 expression in APs but not mature adipocytes due to diminished IL4 receptor expression in the latter. In human visceral and subcutaneous adipose tissue, AZIN2 expression positively correlates with expression of early progenitor markers and genes associated with protection against insulin resistance, while it negatively correlates with markers of lipogenesis. In sum, AZIN2-driven polyamine metabolism preserves adipose tissue health, a finding that could be therapeutically harnessed for the management of obesity-associated metabolic disease.

cell biology↗

bioRxiv2021

SARS-CoV-2 papain-like protease PLpro in complex with natural compounds reveal allosteric sites for antiviral drug design

SARS-CoV-2 papain-like protease (PLpro) covers multiple functions. Beside the cysteine-protease activity, PLpro has the additional and vital function of removing ubiquitin and ISG15 (Interferon-stimulated gene 15) from host-cell proteins to aid coronaviruses in evading the hosts innate immune responses. We established a high-throughput X-ray screening to identify inhibitors by elucidating the native PLpro structure refined to 1.42 [A] and performing co-crystallization utilizing a diverse library of selected natural compounds. We identified three phenolic compounds as potential inhibitors. Crystal structures of PLpro inhibitor complexes, obtained to resolutions between 1.7-1.9 [A], show that all three compounds bind at the ISG15/Ub-S2 allosteric binding site, preventing the essential ISG15-PLpro molecular interactions. All compounds demonstrate clear inhibition in a deISGylation assay, two exhibit distinct antiviral activity and one inhibited a cytopathic effect in a non-cytotoxic concentration range. These results highlight the druggability of the rarely explored ISG15/Ub-S2 PLpro allosteric binding site to identify new and effective antiviral compounds. Importantly, in the context of increasing PLpro mutations in the evolving new variants of SARS-CoV-2, the natural compounds we identified may also reinstate the antiviral immune response processes of the host that are down-regulated in COVID-19 infections.

biochemistry↗

bioRxiv2020

Massive X-ray screening reveals two allosteric drug binding sites of SARS-CoV-2 main protease

The coronavirus disease (COVID-19) caused by SARS-CoV-2 is creating tremendous health problems and economical challenges for mankind. To date, no effective drug is available to directly treat the disease and prevent virus spreading. In a search for a drug against COVID-19, we have performed a massive X-ray crystallographic screen of two repurposing drug libraries against the SARS-CoV-2 main protease (Mpro), which is essential for the virus replication and, thus, a potent drug target. In contrast to commonly applied X-ray fragment screening experiments with molecules of low complexity, our screen tested already approved drugs and drugs in clinical trials. From the three-dimensional protein structures, we identified 37 compounds binding to Mpro. In subsequent cell-based viral reduction assays, one peptidomimetic and five non-peptidic compounds showed antiviral activity at non-toxic concentrations. We identified two allosteric binding sites representing attractive targets for drug development against SARS-CoV-2.

biophysics↗

bioRxiv2020

Catalytic cleavage of HEAT and subsequent covalent binding of the tetralone moiety by the SARS-CoV-2 main protease

Here we present the crystal structure of SARS-CoV-2 main protease (Mpro) covalently bound to 2-methyl-1-tetralone. This complex was obtained by co-crystallization of Mpro with HEAT (2-(((4-hydroxyphenethyl)amino)methyl)-3,4-dihydronaphthalen-1(2H)-one) in the framework of a large X-ray crystallographic screening project of Mpro against a drug repurposing library, consisting of 5632 approved drugs or compounds in clinical phase trials. Further investigations showed that HEAT is cleaved by Mpro in an E1cB-like reaction mechanism into 2-methylene-1-tetralone and tyramine. The catalytic Cys145 subsequently binds covalently in a Michael addition to the methylene carbon atom of 2-methylene-1-tetralone. According to this postulated model HEAT is acting in a pro-drug-like fashion. It is metabolized by Mpro, followed by covalent binding of one metabolite to the active site. The structure of the covalent adduct elucidated in this study opens up a new path for developing non-peptidic inhibitors.

biophysics↗