Purification of a New Extracellular 90–kDa Serine Proteinase with Isoelectric Point of 3.9 fromBacillus subtilis(natto) and Elucidation of Its Distinct Mode of Action

The respiratory disease COVID-19 is caused by the coronavirus SARS-CoV-2. Here we report the discovery of ethacridine as a potent drug against SARS-CoV-2 (EC50 ~ 0.08 μM). Ethacridine was identified via high-throughput screening of an FDA-approved drug library in living cells using a fluorescence assay. Plaque assays, RT-PCR and immunofluorescence imaging at various stages of viral infection demonstrate that the main mode of action of ethacridine is through inactivation of viral particles, preventing their binding to the host cells. Consistently, ethacridine is effective in various cell types, including primary human nasal epithelial cells that are cultured in an air-liquid interface. Taken together, our work identifies a promising, potent, and new use of the old drug via a distinct mode of action for inhibiting SARS-CoV-2.

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Effects of 5-5'-Diphenyl-2-thiohydantoin (DPTH) and Thyroxine on the Ultrastructure and Chemical Composition of Rat Liver

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100066917 ◽

1971 ◽

Vol 29 ◽

pp. 570-571

Author(s):

E. A. Elfont ◽

R. B. Tobin ◽

D. G. Colton ◽

M. A. Mehlman

Keyword(s):

Chemical Composition ◽

Rat Liver ◽

Future Study ◽

Mode Of Action ◽

Liver Mitochondria ◽

Rat Liver Mitochondria ◽

Effective Inhibitor ◽

Biochemical Effects ◽

Glycerophosphate Dehydrogenase ◽

Stimulation Of

Summary5,-5'-diphenyl-2-thiohydantoin (DPTH) is an effective inhibitor of thyroxine (T4) stimulation of α-glycerophosphate dehydrogenase in rat liver mitochondria. Because this finding indicated a possible tool for future study of the mode of action of thyroxine, the ultrastructural and biochemical effects of DPTH and/or thyroxine on rat liver mere investigated.Rats were fed either standard or DPTH (0.06%) diet for 30 days before T4 (250 ug/kg/day) was injected. Injection of T4 occurred daily for 10 days prior to sacrifice. After removal of the liver and kidneys, part of the tissue was frozen at -50°C for later biocheailcal analyses, while the rest was prefixed in buffered 3.5X glutaraldehyde (390 mOs) and post-fixed in buffered 1Z OsO4 (376 mOs). Tissues were embedded in Araldlte 502 and the sections examined in a Zeiss EM 9S.Hepatocytes from hyperthyroid rats (Fig. 2) demonstrated enlarged and more numerous mitochondria than those of controls (Fig. 1). Glycogen was almost totally absent from the cytoplasm of the T4-treated rats.

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Mode of action of calcimycin (A 23187) — II — A study of its interactions ith alkali and alkali-earth cations in methanol-water mixtures

Journal de Chimie Physique ◽

10.1051/jcp/1985820899 ◽

1985 ◽

Vol 82 ◽

pp. 899-906 ◽

Cited By ~ 5

Author(s):

C. Tissier ◽

J. Juillard ◽

D.W. Boyd ◽

A.M. Albrecht-Gary

Keyword(s):

Mode Of Action ◽

Alkali Earth ◽

A 23187

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Antibiotic mode of action profiling (Biomap) as a platform for the discovery of novel natural product antibiotics

Planta Medica ◽

10.1055/s-0032-1320307 ◽

2012 ◽

Vol 78 (11) ◽

Author(s):

W Ruh Wong ◽

AG Oliver ◽

RG Linington

Keyword(s):

Natural Product ◽

Mode Of Action

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Cross-Linked αsγt-Chain Hybrids in Plasma Clots Studied by 1D- and 2D Electrophoresis and Western Blotting

Thrombosis and Haemostasis ◽

10.1055/s-0038-1649601 ◽

1993 ◽

Vol 70 (03) ◽

pp. 438-442 ◽

Cited By ~ 6

Author(s):

B Grøn ◽

C Filion-Myklebust ◽

S Bjørnsen ◽

P Haidaris ◽

F Brosstad

Keyword(s):

Molecular Weight ◽

Monoclonal Antibodies ◽

Human Plasma ◽

Western Blotting ◽

Isoelectric Point ◽

Factor Xiii ◽

Cross Linking ◽

2D Electrophoresis ◽

Complex Phenomenon ◽

Fibrinopeptide A

SummaryFibrinogen and fibrin related chains in reduced human plasma as well as the bonds interlinking partially cross-linked fibrin from plasma clots have been studied by means of 1D- and 2D electrophoresis and Western blotting. Immunovisualization of reduced plasma or partially cross-linked fibrin with monoclonal antibodies specific for the α-chains or the γ-chains have shown that several bands represent material belonging to both chains. In order to decide whether these bands constitute αγ-chain hybrids or superimposed α- and γ-chain dimers, the cross-linked material was separated according to both isoelectric point (pI) and molecular weight (MW) using Pharmacia’s Multiphor II system. Western blotting of the second dimension gels revealed that partially cross-linked fibrin contains αsγt-chain hybrids and γ- polymers, in addition to the well-known γ-dimers and α-polymers. The main αsγt-chain hybrid has a pI between that of the α- and the γ-chains, a MW of about 200 kDa and contains Aα-chains with intact fibrinopeptide A (FPA). It was also observed that soluble fibrinogen/fibrin complexes as well as partially cross-linked fibrin contain degraded α-dimers with MWs close to the γ-dimers. These findings demonstrate that factor XIII-catalyzed cross-linking of fibrin is a more complex phenomenon than earlier recognized.

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A Comparison of Plasminogen Activators Derived from Rat Plasma, Primary Rat Hepatocytes and Isolated Perfused Rat Liver

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657155 ◽

1982 ◽

Vol 47 (02) ◽

pp. 166-172 ◽

Cited By ~ 4

Author(s):

Yoav Sharoni ◽

Maria C Topal ◽

Patricia R Tuttle ◽

Henry Berger

Keyword(s):

Rat Liver ◽

Isoelectric Point ◽

Rat Hepatocytes ◽

Cell Types ◽

Plasminogen Activators ◽

Rat Plasma ◽

Isolated Perfused Rat Liver ◽

Perfused Rat Liver ◽

Molecular Weights ◽

Physiological Relevance

SummaryOf the two cell types it was possible to culture from the dissociated rat liver, hepatocytes and Kupffer cells, only the former were fibrinolytically active. Rat hepatocytes during the first 24 hr in culture secreted two plasminogen activators with molecular weights identical to those found in rat plasma, an 80,000-dalton form (PA-80) and a 45,000-dalton form (PA-45). Partially purified preparations of plasminogen activators from both sources were subjected to isoelectric focusing (IEF) to compare characteristics further. There were three distinct peaks of PA-45 in each preparation with isoelectric points of 7.1, 7.2 and 7.4; all electrophoretic forms had the same low affinity to fibrin. PA-80 from both sources displayed similar IEF profiles with forms ranging from pH values of 7 to 8, all with the same high affinity to fibrin. The major form of PA-80 in the plasma preparation had an isoelectric point of 7.9 whereas that in the hepatocyte preparation had an isoelectric point of 7.6. The isolated perfused rat liver was also shown to produce both PA-80 and PA-45 emphasizing the physiological relevance of the findings with hepatocytes. It is concluded that in the rat hepatocytes contribute to the plasma profile with regard to the plasminogen activator content.

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