Protease S of entomopathogenic bacterium Photorhabdus laumondii: expression, purification and effect on greater wax moth Galleria mellonella.

Background: Protease S (PrtS) from Photorhabdus laumondii belongs to the group of protealysin-like proteases (PLPs), which are understudied factors thought to play a role in the interaction of bacteria with other organisms. Since P. laumondii is an insect pathogen and a nematode symbiont, the analysis of the biological functions of PLPs using the PrtS model provides novel data on diverse types of interactions between bacteria and hosts.

Expression and Purification of His-Tagged Variants of Human Hepatitis A Virus 3C Protease.

Background: Protease 3C (3Cpro) is the only protease encoded in the human hepatitis A virus genome and is considered as a potential target for antiviral drugs due to its critical role in the viral life cycle. Additionally, 3Cpro has been identified as a potent inducer of ferroptosis, a newly described type of cell death. Therefore, studying the molecular mechanism of 3Cpro functioning can provide new insights into viral-host interaction and the biological role of ferroptosis.

Production and Characterization of Photorin, a Novel Proteinaceous Protease Inhibitor from the Entomopathogenic Bacteria Photorhabdus laumondii.

Entomopathogenic bacteria of the genus Photorhabdus secrete protease S (PrtS), which is considered a virulence factor. We found that in the Photorhabdus genomes, immediately after the prtS genes, there are genes that encode small hypothetical proteins homologous to emfourin, a recently discovered protein inhibitor of metalloproteases. The gene of emfourin-like inhibitor from Photorhabdus laumondii subsp.

Efficiency of Promoters of Human Genes and at Organism Level in a Model.

The identification of tissue-specific promoters for gene therapeutic constructs is one of the aims of complex tumor therapy. The genes encoding the fibroblast activation protein () and the connective tissue growth factor () can function in tumor-associated stromal cells but are practically inactive in normal adult cells. Accordingly, the promoters of these genes can be used to develop vectors targeted to the tumor microenvironment.

NMR structure of emfourin, a novel protein metalloprotease inhibitor: Insights into the mechanism of action.

Emfourin (M4in) is a protein metalloprotease inhibitor recently discovered in the bacterium Serratia proteamaculans and the prototype of a new family of protein protease inhibitors with an unknown mechanism of action. Protealysin-like proteases (PLPs) of the thermolysin family are natural targets of emfourin-like inhibitors widespread in bacteria and known in archaea. The available data indicate the involvement of PLPs in interbacterial interaction as well as bacterial interaction with other organisms and likely in pathogenesis.

Protealysin Targets the Bacterial Housekeeping Proteins FtsZ and RecA.

synthesizes the intracellular metalloprotease protealysin. This work was aimed at searching for bacterial substrates of protealysin among the proteins responsible for replication and cell division. We have shown that protealysin unlimitedly cleaves the SOS response protein RecA.

The SARS-CoV-2 main protease doesn't induce cell death in human cells in vitro.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of coronavirus disease 2019 (COVID-19) which has extremely rapidly spread worldwide. In order to develop the effective antiviral therapies, it is required to understand the molecular mechanisms of the SARS-CoV-2 pathogenesis. The main protease, or 3C-like protease (3CLpro), plays the essential role in the coronavirus replication that makes the enzyme a promising therapeutic target.

Embryotoxic activity of 3C protease of human hepatitis A virus in developing Danio rerio embryos.

The 3C protease is a key factor in picornavirus-induced pathologies with a comprehensive action on cell targets. However, the effects induced by the enzyme have not been described at the organismic level. Here, the model of developing Danio rerio embryos was used to analyze possible toxic effects of the 3C protease of human hepatitis A virus (3Cpro) at the whole-body level.

Individual Expression of Hepatitis A Virus 3C Protease Induces Ferroptosis in Human Cells In Vitro.

Regulated cell death (RCD) is a fundamental process common to nearly all living beings and essential for the development and tissue homeostasis in animals and humans. A wide range of molecules can induce RCD, including a number of viral proteolytic enzymes. To date, numerous data indicate that picornaviral 3C proteases can induce RCD.

NMR assignments and secondary structure distribution of emfourin, a novel proteinaceous protease inhibitor.

Emfourin (M4in) from Serratia proteamaculans is a new proteinaceous inhibitor of protealysin-like proteases (PLPs), a subgroup of the well-known and widely represented metallopeptidase M4 family. Although the biological role of PLPs is debatable, data published indicate their involvement in pathogenesis, including bacterial invasion into eukaryotic cells, suppression of immune defense of some animals, and destruction of plant cell walls. Gene colocalization into a bicistronic operon observed for some PLPs and their inhibitors (as in the case of M4in) implies a mutually consistent functioning of both entities.

The protealysin operon encodes emfourin, a prototype of a novel family of protein metalloprotease inhibitors.

Protealysin is a Serratia proteamaculans metalloproteinase of the M4 peptidase family and the prototype of a large group of protealysin-like proteases (PLPs). PLPs are likely involved in bacterial interaction with plants and animals as well as in bacterial pathogenesis. We demonstrated that the PLP genes in bacteria colocalize with the genes of putative conserved proteins.

Cleavage of the outer membrane protein OmpX by protealysin regulates Serratia proteamaculans invasion.

Protealysin is a thermolysin-like protease of Serratia proteamaculans capable of specifically cleaving actin, which correlates with the invasive activity of these bacteria. Here, we show that inactivation of the protealysin gene does not inhibit invasion but, in contrast, leads to a twofold increase in the S. proteamaculans invasive activity.

Functional efficiency of PCR vectors in vitro and at the organism level.

The functional efficiency of the expression cassettes integrated into a plasmid and a PCR- amplified fragment was comparatively analyzed after transient transfection in vitro or introduction into the developing embryo of Danio rerio. The cassettes contained the reporter genes, luciferase of Photinus pyralis (luc) or enhanced green fluorescent protein, under the control of the promoter of human cytomegalovirus immediate-early genes. In the in vitro system, the efficiency of the circular plasmid was 2.

SprI/SprR Quorum Sensing System of 94.

In this study, we investigated the quorum sensing (QS) regulatory system of the psychrotrophic strain 94 isolated from spoiled refrigerated meat. The strain produced several -acyl--homoserine-lactone (AHL) QS signal molecules, with -(3-oxo-hexanoyl)--homoserine lactone and -(3-hydroxy-hexanoyl)--homoserine lactone as two main types. The and genes encoding an AHL synthase and a receptor regulatory protein, respectively, were cloned and sequenced.

An Internally Quenched Fluorescent Peptide Substrate for Protealysin.

Protealysin, a metalloprotease of Serratia proteamaculans, is the prototype of a subgroup of the M4 peptidase family. Protealysin-like proteases (PLPs) are widely spread in bacteria but also occur in fungi and certain archaea. The interest in PLPs is primarily due to their putative involvement in the bacterial pathogenesis in animals and plants.

Protealysin is not Secreted Constitutively.

Background: Protealysin, a zinc metalloprotease of Serratia proteamaculans, is the prototype of a new group within the peptidase family M4. Protealysin-like proteases (PLPs) are widely spread in bacteria but are also found in fungi and archaea. The biological functions of PLPs have not been well studied, but published data showed the involvement of enzymes of this group in the interaction of bacteria with higher organisms, and most likely in the pathogenesis.

Disturbed processing of the carbohydrate-binding module of family 54 significantly impairs its binding to polysaccharides.

Carbohydrate-binding modules of the family 54 (CBM54) are characterized by spontaneous rupture of the peptide bond Asn266-Ser267 (numbering corresponds to that of laminarinase Lic16A of Ruminiclostridium thermocellum). As a result of processing, two parts are formed noncovalently connected to each other. Here, to gain insights into the functional significance of the internal cleavage, we made modifications of the family-conserved processing site in CBM54 of Lic16A.

Сarbohydrate binding module CBM28 of endoglucanase Cel5D from Caldicellulosiruptor bescii recognizes crystalline cellulose.

Optimal catalytic activity of endoglucanase Cel5D from the thermophilic anaerobic bacterium Caldicellulosiruptor bescii requires the presence of a carbohydrate-binding module of family 28, CbCBM28. The binding properties of CbСВМ28 with cello-, laminari-, xylo- and chito-oligosaccharides were studied by isothermal titration calorimetry. CbСВМ28 bound only cello-oligosaccharides comprising at least four glucose residues with binding constants of 2.

Cytoplasmic vacuolization in cell death and survival.

Cytoplasmic vacuolization (also called cytoplasmic vacuolation) is a well-known morphological phenomenon observed in mammalian cells after exposure to bacterial or viral pathogens as well as to various natural and artificial low-molecular-weight compounds. Vacuolization often accompanies cell death; however, its role in cell death processes remains unclear. This can be attributed to studying vacuolization at the level of morphology for many years.

The Propeptide is Required for In Vivo Formation of Active Protealysin.

Two structurally distinct N-terminal propeptides are known in thermolysin-like proteases (TLPs). Propeptides of the first type are similar to the prosequence of thermolysin, while the second type propeptides resemble the protealysin propeptide. At the same time, the catalytic domains of all enzymes of the family are highly similar.

Protease 3C of hepatitis A virus induces vacuolization of lysosomal/endosomal organelles and caspase-independent cell death.

Background: 3C proteases, the main proteases of picornaviruses, play the key role in viral life cycle by processing polyproteins. In addition, 3C proteases digest certain host cell proteins to suppress antiviral defense, transcription, and translation. The activity of 3C proteases per se induces host cell death, which makes them critical factors of viral cytotoxicity.

Cloning, sequencing, expression, and characterization of thermostability of oligopeptidase B from Serratia proteamaculans, a novel psychrophilic protease.

Protease from Serratia proteamaculans (PSP) is the first known psychrophilic oligopeptidase B. The gene of S. proteamaculans 94 oligopeptidase B was cloned, sequenced and expressed in Escherichia coli.

Alterations in gene expression of proprotein convertases in human lung cancer have a limited number of scenarios.

Proprotein convertases (PCs) is a protein family which includes nine highly specific subtilisin-like serine endopeptidases in mammals. The system of PCs is involved in carcinogenesis and levels of PC mRNAs alter in cancer, which suggests expression status of PCs as a possible marker for cancer typing and prognosis. The goal of this work was to assess the information value of expression profiling of PC genes.