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Sample records for coronavirus 3c-like protease

  1. Potent Inhibition of Feline Coronaviruses with Peptidyl Compounds Targeting Coronavirus 3C-like Protease

    Science.gov (United States)

    Kim, Yunjeong; Mandadapu, Sivakoteswara Rao; Groutas, William C.; Chang, Kyeong-Ok

    2012-01-01

    Feline coronavirus infection is common among domestic and exotic felid species and usually associated with mild or asymptomatic enteritis; however, feline infectious peritonitis (FIP) is a fatal disease of cats that is caused by systemic infection with a feline infectious peritonitis virus (FIPV), a variant of feline enteric coronavirus (FECV). Currently, there is no specific treatment approved for FIP despite the importance of FIP as the leading infectious cause of death in young cats. During the replication process, coronavirus produces viral polyproteins that are processed into mature proteins by viral proteases, the main protease (3C-like [3CL] protease) and the papain-like protease. Since the cleavages of viral polyproteins are an essential step for virus replication, blockage of viral protease is an attractive target for therapeutic intervention. Previously, we reported the generation of broad-spectrum peptidyl inhibitors against viruses that possess a 3C or 3CL protease. In this study, we further evaluated the antiviral effects of the peptidyl inhibitors against feline coronaviruses, and investigated the interaction between our protease inhibitor and a cathepsin B inhibitor, an entry blocker, against feline coronaviruses in cell culture. Herein we report that our compounds behave as reversible, competitive inhibitors of 3CL protease, potently inhibited the replication of feline coronaviruses (EC50 in a nanomolar range) and, furthermore, the combination of cathepsin B and 3CL protease inhibitors led to a strong synergistic interaction against feline coronaviruses in cell culture systems. PMID:23219425

  2. Broad-Spectrum Inhibitors against 3C-Like Proteases of Feline Coronaviruses and Feline Caliciviruses

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    Shivanna, Vinay; Narayanan, Sanjeev; Prior, Allan M.; Weerasekara, Sahani; Hua, Duy H.; Kankanamalage, Anushka C. Galasiti; Groutas, William C.; Chang, Kyeong-Ok

    2015-01-01

    ABSTRACT Feline infectious peritonitis and virulent, systemic calicivirus infection are caused by certain types of feline coronaviruses (FCoVs) and feline caliciviruses (FCVs), respectively, and are important infectious diseases with high fatality rates in members of the Felidae family. While FCoV and FCV belong to two distinct virus families, the Coronaviridae and the Caliciviridae, respectively, they share a dependence on viral 3C-like protease (3CLpro) for their replication. Since 3CLpro is functionally and structurally conserved among these viruses and essential for viral replication, 3CLpro is considered a potential target for the design of antiviral drugs with broad-spectrum activities against these distinct and highly important viral infections. However, small-molecule inhibitors against the 3CLpro enzymes of FCoV and FCV have not been previously identified. In this study, derivatives of peptidyl compounds targeting 3CLpro were synthesized and evaluated for their activities against FCoV and FCV. The structures of compounds that showed potent dual antiviral activities with a wide margin of safety were identified and are discussed. Furthermore, the in vivo efficacy of 3CLpro inhibitors was evaluated using a mouse model of coronavirus infection. Intraperitoneal administration of two 3CLpro inhibitors in mice infected with murine hepatitis virus A59, a hepatotropic coronavirus, resulted in significant reductions in virus titers and pathological lesions in the liver compared to the findings for the controls. These results suggest that the series of 3CLpro inhibitors described here may have the potential to be further developed as therapeutic agents against these important viruses in domestic and wild cats. This study provides important insights into the structure and function relationships of 3CLpro for the design of antiviral drugs with broader antiviral activities. IMPORTANCE Feline infectious peritonitis virus (FIPV) is the leading cause of death in young cats

  3. Design, synthesis and crystallographic analysis of nitrile-based broad-spectrum peptidomimetic inhibitors for coronavirus 3C-like proteases.

    Science.gov (United States)

    Chuck, Chi-Pang; Chen, Chao; Ke, Zhihai; Wan, David Chi-Cheong; Chow, Hak-Fun; Wong, Kam-Bo

    2013-01-01

    Coronaviral infection is associated with up to 5% of respiratory tract diseases. The 3C-like protease (3CL(pro)) of coronaviruses is required for proteolytic processing of polyproteins and viral replication, and is a promising target for the development of drugs against coronaviral infection. We designed and synthesized four nitrile-based peptidomimetic inhibitors with different N-terminal protective groups and different peptide length, and examined their inhibitory effect on the in-vitro enzymatic activity of 3CL(pro) of severe-acute-respiratory-syndrome-coronavirus. The IC(50) values of the inhibitors were in the range of 4.6-49 μM, demonstrating that the nitrile warhead can effectively inactivate the 3CL(pro) autocleavage process. The best inhibitor, Cbz-AVLQ-CN with an N-terminal carbobenzyloxy group, was ~10x more potent than the other inhibitors tested. Crystal structures of the enzyme-inhibitor complexes showed that the nitrile warhead inhibits 3CL(pro) by forming a covalent bond with the catalytic Cys145 residue, while the AVLQ peptide forms a number of favourable interactions with the S1-S4 substrate-binding pockets. We have further showed that the peptidomimetic inhibitor, Cbz-AVLQ-CN, has broad-spectrum inhibition against 3CL(pro) from human coronavirus strains 229E, NL63, OC43, HKU1, and infectious bronchitis virus, with IC(50) values ranging from 1.3 to 3.7 μM, but no detectable inhibition against caspase-3. In summary, we have shown that the nitrile-based peptidomimetic inhibitors are effective against 3CL(pro), and they inhibit 3CL(pro) from a broad range of coronaviruses. Our results provide further insights into the future design of drugs that could serve as a first line defence against coronaviral infection. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  4. Mechanism for Controlling the Dimer-Monomer Switch and Coupling Dimerization to Catalysis of the Severe Acute Respiratory Syndrome Coronavirus 3C-Like Protease

    Energy Technology Data Exchange (ETDEWEB)

    Shi,J.; Sivaraman, J.; Song, J.

    2008-01-01

    Unlike 3C protease, the severe acute respiratory syndrome coronavirus (SARS-CoV) 3C-like protease (3CLpro) is only enzymatically active as a homodimer and its catalysis is under extensive regulation by the unique extra domain. Despite intense studies, two puzzles still remain: (i) how the dimer-monomer switch is controlled and (ii) why dimerization is absolutely required for catalysis. Here we report the monomeric crystal structure of the SARS-CoV 3CLpro mutant R298A at a resolution of 1.75 Angstroms . Detailed analysis reveals that Arg298 serves as a key component for maintaining dimerization, and consequently, its mutation will trigger a cooperative switch from a dimer to a monomer. The monomeric enzyme is irreversibly inactivated because its catalytic machinery is frozen in the collapsed state, characteristic of the formation of a short 310-helix from an active-site loop. Remarkably, dimerization appears to be coupled to catalysis in 3CLpro through the use of overlapped residues for two networks, one for dimerization and another for the catalysis.

  5. Porcine Epidemic Diarrhea Virus 3C-Like Protease-Mediated Nucleocapsid Processing: Possible Link to Viral Cell Culture Adaptability.

    Science.gov (United States)

    Jaru-Ampornpan, Peera; Jengarn, Juggragarn; Wanitchang, Asawin; Jongkaewwattana, Anan

    2017-01-15

    Porcine epidemic diarrhea virus (PEDV) causes severe diarrhea and high mortality rates in newborn piglets, leading to massive losses to the swine industry worldwide during recent epidemics. Intense research efforts are now focusing on defining viral characteristics that confer a growth advantage, pathogenicity, or cell adaptability in order to better understand the PEDV life cycle and identify suitable targets for antiviral or vaccine development. Here, we report a unique phenomenon of PEDV nucleocapsid (N) cleavage by the PEDV-encoded 3C-like protease (3Cpro) during infection. The identification of the 3Cpro cleavage site at the C terminus of N supported previous observations that PEDV 3Cpro showed a substrate requirement slightly different from that of severe acute respiratory syndrome coronavirus (SARS-CoV) 3Cpro and revealed a greater flexibility in its substrate recognition site. This cleavage motif is present in the majority of cell culture-adapted PEDV strains but is missing in emerging field isolates. Remarkably, reverse-genetics-derived cell culture-adapted PEDV AVCT12 harboring uncleavable N displayed growth retardation in Vero E6-APN cells compared to the wild-type virus. These observations altogether shed new light on the investigation and characterization of the PEDV nucleocapsid protein and its possible link to cell culture adaptation. Recurrent PEDV outbreaks have resulted in enormous economic losses to swine industries worldwide. To gain the upper hand in combating this disease, it is necessary to understand how this virus replicates and evades host immunity. Characterization of viral proteins provides important clues to mechanisms by which viruses survive and spread. Here, we characterized an intriguing phenomenon in which the nucleocapsids of some PEDV strains are proteolytically processed by the virally encoded main protease. Growth retardation in recombinant PEDV carrying uncleavable N suggests a replication advantage provided by the cleavage

  6. Inhibition of SARS-CoV 3C-like Protease Activity by Theaflavin-3,3'-digallate (TF3

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    Chia-Nan Chen

    2005-01-01

    Full Text Available SARS-CoV is the causative agent of severe acute respiratory syndrome (SARS. The virally encoded 3C-like protease (3CLPro has been presumed critical for the viral replication of SARS-CoV in infected host cells. In this study, we screened a natural product library consisting of 720 compounds for inhibitory activity against 3CLPro. Two compounds in the library were found to be inhibitive: tannic acid (IC50 = 3 µM and 3-isotheaflavin-3-gallate (TF2B (IC50 = 7 µM. These two compounds belong to a group of natural polyphenols found in tea. We further investigated the 3CLPro-inhibitory activity of extracts from several different types of teas, including green tea, oolong tea, Puer tea and black tea. Our results indicated that extracts from Puer and black tea were more potent than that from green or oolong teas in their inhibitory activities against 3CLPro. Several other known compositions in teas were also evaluated for their activities in inhibiting 3CLPro. We found that caffeine, (—-epigallocatechin gallte (EGCg, epicatechin (EC, theophylline (TP, catechin (C, epicatechin gallate (ECg and epigallocatechin (EGC did not inhibit 3CLPro activity. Only theaflavin-3,3′-digallate (TF3 was found to be a 3CLPro inhibitor. This study has resulted in the identification of new compounds that are effective 3CLPro inhibitors.

  7. Efficacy of a 3C-like protease inhibitor in treating various forms of acquired feline infectious peritonitis.

    Science.gov (United States)

    Pedersen, Niels C; Kim, Yunjeong; Liu, Hongwei; Galasiti Kankanamalage, Anushka C; Eckstrand, Chrissy; Groutas, William C; Bannasch, Michael; Meadows, Juliana M; Chang, Kyeong-Ok

    2018-04-01

    Objectives The safety and efficacy of the 3C-like protease inhibitor GC376 was tested on a cohort of client-owned cats with various forms of feline infectious peritonitis (FIP). Methods Twenty cats from 3.3-82 months of age (mean 10.4 months) with various forms of FIP were accepted into a field trial. Fourteen cats presented with wet or dry-to-wet FIP and six cats presented with dry FIP. GC376 was administered subcutaneously every 12 h at a dose of 15 mg/kg. Cats with neurologic signs were excluded from the study. Results Nineteen of 20 cats treated with GC376 regained outward health within 2 weeks of initial treatment. However, disease signs recurred 1-7 weeks after primary treatment and relapses and new cases were ultimately treated for a minimum of 12 weeks. Relapses no longer responsive to treatment occurred in 13 of these 19 cats within 1-7 weeks of initial or repeat treatment(s). Severe neurologic disease occurred in 8/13 cats that failed treatment and five cats had recurrences of abdominal lesions. At the time of writing, seven cats were in disease remission. Five kittens aged 3.3-4.4 months with wet FIP were treated for 12 weeks and have been in disease remission after stopping treatment and at the time of writing for 5-14 months (mean 11.2 months). A sixth kitten was in remission for 10 weeks after 12 weeks of treatment, relapsed and is responding to a second round of GC376. The seventh was a 6.8-year-old cat with only mesenteric lymph node involvement that went into remission after three relapses that required progressively longer repeat treatments over a 10 month period. Side effects of treatment included transient stinging upon injection and occasional foci of subcutaneous fibrosis and hair loss. There was retarded development and abnormal eruption of permanent teeth in cats treated before 16-18 weeks of age. Conclusions and relevance GC376 showed promise in treating cats with certain presentations of FIP and has opened the door to targeted antiviral

  8. Identification of Cleavage Sites Recognized by the 3C-Like Cysteine Protease within the Two Polyproteins of Strawberry Mottle Virus

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    Hélène Sanfaçon

    2017-04-01

    Full Text Available Strawberry mottle virus (SMoV, family Secoviridae, order Picornavirales is one of several viruses found in association with strawberry decline disease in Eastern Canada. The SMoV genome consists of two positive-sense single-stranded RNAs, each encoding one large polyprotein. The RNA1 polyprotein (P1 includes the domains for a putative helicase, a VPg, a 3C-like cysteine protease and an RNA-dependent RNA polymerase at its C-terminus, and one or two protein domains at its N-terminus. The RNA2 polyprotein (P2 is predicted to contain the domains for a movement protein (MP and one or several coat proteins at its N-terminus, and one or more additional domains for proteins of unknown function at its C-terminus. The RNA1-encoded 3C-like protease is presumed to cleave the two polyproteins in cis (P1 and in trans (P2. Using in vitro processing assays, we systematically scanned the two polyproteins for cleavage sites recognized by this protease. We identified five cis-cleavage sites in P1, with cleavage between the putative helicase and VPg domains being the most efficient. The presence of six protein domains in the SMoV P1, including two upstream of the putative helicase domain, is a feature shared with nepoviruses but not with comoviruses. Results from trans-cleavage assays indicate that the RNA1-encoded 3C-like protease recognized a single cleavage site, which was between the predicted MP and coat protein domains in the P2 polyprotein. The cleavage site consensus sequence for the SMoV 3C-like protease is AxE (E or Q/(G or S.

  9. Reversal of the Progression of Fatal Coronavirus Infection in Cats by a Broad-Spectrum Coronavirus Protease Inhibitor.

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    Yunjeong Kim

    2016-03-01

    Full Text Available Coronaviruses infect animals and humans causing a wide range of diseases. The diversity of coronaviruses in many mammalian species is contributed by relatively high mutation and recombination rates during replication. This dynamic nature of coronaviruses may facilitate cross-species transmission and shifts in tissue or cell tropism in a host, resulting in substantial change in virulence. Feline enteric coronavirus (FECV causes inapparent or mild enteritis in cats, but a highly fatal disease, called feline infectious peritonitis (FIP, can arise through mutation of FECV to FIP virus (FIPV. The pathogenesis of FIP is intimately associated with immune responses and involves depletion of T cells, features shared by some other coronaviruses like Severe Acute Respiratory Syndrome Coronavirus. The increasing risks of highly virulent coronavirus infections in humans or animals call for effective antiviral drugs, but no such measures are yet available. Previously, we have reported the inhibitors that target 3C-like protease (3CLpro with broad-spectrum activity against important human and animal coronaviruses. Here, we evaluated the therapeutic efficacy of our 3CLpro inhibitor in laboratory cats with FIP. Experimental FIP is 100% fatal once certain clinical and laboratory signs become apparent. We found that antiviral treatment led to full recovery of cats when treatment was started at a stage of disease that would be otherwise fatal if left untreated. Antiviral treatment was associated with a rapid improvement in fever, ascites, lymphopenia and gross signs of illness and cats returned to normal health within 20 days or less of treatment. Significant reduction in viral titers was also observed in cats. These results indicate that continuous virus replication is required for progression of immune-mediated inflammatory disease of FIP. These findings may provide important insights into devising therapeutic strategies and selection of antiviral compounds for

  10. X-ray structure and inhibition of the feline infectious peritonitis virus 3C-like protease: Structural implications for drug design.

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    St John, Sarah E; Therkelsen, Matthew D; Nyalapatla, Prasanth R; Osswald, Heather L; Ghosh, Arun K; Mesecar, Andrew D

    2015-11-15

    Feline infectious peritonitis (FIP) is a deadly disease that effects both domestic and wild cats and is caused by a mutation in feline coronavirus (FCoV) that allows the virus to replicate in macrophages. Currently, there are no treatments or vaccines available for the treatment of FIP even though it kills approximately 5% of cats in multi-cat households per year. In an effort to develop small molecule drugs targeting FIP for the treatment of cats, we screened a small set of designed peptidomimetic inhibitors for inhibition of FIPV-3CL(pro), identifying two compounds with low to sub-micromolar inhibition, compound 6 (IC50=0.59±0.06 μM) and compound 7 (IC50=1.3±0.1 μM). We determined the first X-ray crystal structure of FIPV-3CL(pro) in complex with the best inhibitor identified, compound 6, to a resolution of 2.10 Å to better understand the structural basis for inhibitor specificity. Our study provides important insights into the structural requirements for the inhibition of FIPV-3CL(pro) by peptidomimetic inhibitors and expands the current structural knowledge of coronaviral 3CL(pro) architecture. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Chimeric exchange of coronavirus nsp5 proteases (3CLpro) identifies common and divergent regulatory determinants of protease activity.

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    Stobart, Christopher C; Sexton, Nicole R; Munjal, Havisha; Lu, Xiaotao; Molland, Katrina L; Tomar, Sakshi; Mesecar, Andrew D; Denison, Mark R

    2013-12-01

    Human coronaviruses (CoVs) such as severe acute respiratory syndrome CoV (SARS-CoV) and Middle East respiratory syndrome CoV (MERS-CoV) cause epidemics of severe human respiratory disease. A conserved step of CoV replication is the translation and processing of replicase polyproteins containing 16 nonstructural protein domains (nsp's 1 to 16). The CoV nsp5 protease (3CLpro; Mpro) processes nsp's at 11 cleavage sites and is essential for virus replication. CoV nsp5 has a conserved 3-domain structure and catalytic residues. However, the intra- and intermolecular determinants of nsp5 activity and their conservation across divergent CoVs are unknown, in part due to challenges in cultivating many human and zoonotic CoVs. To test for conservation of nsp5 structure-function determinants, we engineered chimeric betacoronavirus murine hepatitis virus (MHV) genomes encoding nsp5 proteases of human and bat alphacoronaviruses and betacoronaviruses. Exchange of nsp5 proteases from HCoV-HKU1 and HCoV-OC43, which share the same genogroup, genogroup 2a, with MHV, allowed for immediate viral recovery with efficient replication albeit with impaired fitness in direct competition with wild-type MHV. Introduction of MHV nsp5 temperature-sensitive mutations into chimeric HKU1 and OC43 nsp5 proteases resulted in clear differences in viability and temperature-sensitive phenotypes compared with MHV nsp5. These data indicate tight genetic linkage and coevolution between nsp5 protease and the genomic background and identify differences in intramolecular networks regulating nsp5 function. Our results also provide evidence that chimeric viruses within coronavirus genogroups can be used to test nsp5 determinants of function and inhibition in common isogenic backgrounds and cell types.

  12. Development of Broad-Spectrum Halomethyl Ketone Inhibitors Against Coronavirus Main Protease 3CL(pro)

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    Bacha,U.; Barilla, J.; Gabelli, S.; Kiso, Y.; Amzel, L.; Freire, E.

    2008-01-01

    Coronaviruses comprise a large group of RNA viruses with diverse host specificity. The emergence of highly pathogenic strains like the SARS coronavirus (SARS-CoV), and the discovery of two new coronaviruses, NL-63 and HKU1, corroborates the high rate of mutation and recombination that have enabled them to cross species barriers and infect novel hosts. For that reason, the development of broad-spectrum antivirals that are effective against several members of this family is highly desirable. This goal can be accomplished by designing inhibitors against a target, such as the main protease 3CLpro (Mpro), which is highly conserved among all coronaviruses. Here 3CLpro derived from the SARS-CoV was used as the primary target to identify a new class of inhibitors containing a halomethyl ketone warhead. The compounds are highly potent against SARS 3CLpro with Ki's as low as 300 nm. The crystal structure of the complex of one of the compounds with 3CLpro indicates that this inhibitor forms a thioether linkage between the halomethyl carbon of the warhead and the catalytic Cys 145. Furthermore, Structure Activity Relationship (SAR) studies of these compounds have led to the identification of a pharmacophore that accurately defines the essential molecular features required for the high affinity.

  13. Cleavage of spike protein of SARS coronavirus by protease factor Xa is associated with viral infectivity

    International Nuclear Information System (INIS)

    Du, Lanying; Kao, Richard Y.; Zhou, Yusen; He, Yuxian; Zhao, Guangyu; Wong, Charlotte; Jiang, Shibo; Yuen, Kwok-Yung; Jin, Dong-Yan; Zheng, Bo-Jian

    2007-01-01

    The spike (S) protein of SARS coronavirus (SARS-CoV) has been known to recognize and bind to host receptors, whose conformational changes then facilitate fusion between the viral envelope and host cell membrane, leading to viral entry into target cells. However, other functions of SARS-CoV S protein such as proteolytic cleavage and its implications to viral infection are incompletely understood. In this study, we demonstrated that the infection of SARS-CoV and a pseudovirus bearing the S protein of SARS-CoV was inhibited by a protease inhibitor Ben-HCl. Also, the protease Factor Xa, a target of Ben-HCl abundantly expressed in infected cells, was able to cleave the recombinant and pseudoviral S protein into S1 and S2 subunits, and the cleavage was inhibited by Ben-HCl. Furthermore, this cleavage correlated with the infectivity of the pseudovirus. Taken together, our study suggests a plausible mechanism by which SARS-CoV cleaves its S protein to facilitate viral infection

  14. Structures of Two Coronavirus Main Proteases: Implications for Substrate Binding and Antiviral Drug Design

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    Xue, Xiaoyu; Yu, Hongwei; Yang, Haitao; Xue, Fei; Wu, Zhixin; Shen, Wei; Li, Jun; Zhou, Zhe; Ding, Yi; Zhao, Qi; Zhang, Xuejun C.; Liao, Ming; Bartlam, Mark; Rao, Zihe (SCAU); (Tsinghua); (Chinese Aca. Sci.)

    2008-07-21

    Coronaviruses (CoVs) can infect humans and multiple species of animals, causing a wide spectrum of diseases. The coronavirus main protease (M{sup pro}), which plays a pivotal role in viral gene expression and replication through the proteolytic processing of replicase polyproteins, is an attractive target for anti-CoV drug design. In this study, the crystal structures of infectious bronchitis virus (IBV) MP{sup pro} and a severe acute respiratory syndrome CoV (SARS-CoV) M{sup pro} mutant (H41A), in complex with an N-terminal autocleavage substrate, were individually determined to elucidate the structural flexibility and substrate binding of M{sup pro}. A monomeric form of IBV M{sup pro} was identified for the first time in CoV M{sup pro} structures. A comparison of these two structures to other available M{sup pro} structures provides new insights for the design of substrate-based inhibitors targeting CoV M{sup pro}s. Furthermore, a Michael acceptor inhibitor (named N3) was cocrystallized with IBV M{sup pro} and was found to demonstrate in vitro inactivation of IBV M{sup pro} and potent antiviral activity against IBV in chicken embryos. This provides a feasible animal model for designing wide-spectrum inhibitors against CoV-associated diseases. The structure-based optimization of N3 has yielded two more efficacious lead compounds, N27 and H16, with potent inhibition against SARS-CoV M{sup pro}.

  15. About Coronavirus

    Science.gov (United States)

    ... Coronaviruses Symptoms and Diagnosis Transmission Prevention and Treatment Human Coronavirus Types SARS-CoV MERS-CoV Resources and References About Coronaviruses Recommend on Facebook Tweet Share Compartir Symptoms and Diagnosis Lists illnesses ...

  16. Biodiversity impact of host interferon-stimulated-gene-product 15 on the coronavirus Papain-like protease deISGylase functions

    Science.gov (United States)

    Coronaviruses are single-stranded, positive sense RNA viruses whose members have severe impact on human health and cause significant economic hardships. Some pertinent examples include severe acute and Middle East respiratory syndromes (SARS-CoV; MERS-CoV), porcine epidemic diarrhea virus (PEDV), an...

  17. Calicivirus 3C-like proteinase inhibits cellular translation by cleavage of poly(A)-binding protein.

    Science.gov (United States)

    Kuyumcu-Martinez, Muge; Belliot, Gaël; Sosnovtsev, Stanislav V; Chang, Kyeong-Ok; Green, Kim Y; Lloyd, Richard E

    2004-08-01

    Caliciviruses are single-stranded RNA viruses that cause a wide range of diseases in both humans and animals, but little is known about the regulation of cellular translation during infection. We used two distinct calicivirus strains, MD145-12 (genus Norovirus) and feline calicivirus (FCV) (genus Vesivirus), to investigate potential strategies used by the caliciviruses to inhibit cellular translation. Recombinant 3C-like proteinases (r3CL(pro)) from norovirus and FCV were found to cleave poly(A)-binding protein (PABP) in the absence of other viral proteins. The norovirus r3CL(pro) PABP cleavage products were indistinguishable from those generated by poliovirus (PV) 3C(pro) cleavage, while the FCV r3CL(pro) products differed due to cleavage at an alternate cleavage site 24 amino acids downstream of one of the PV 3C(pro) cleavage sites. All cleavages by calicivirus or PV proteases separated the C-terminal domain of PABP that binds translation factors eIF4B and eRF3 from the N-terminal RNA-binding domain of PABP. The effect of PABP cleavage by the norovirus r3CL(pro) was analyzed in HeLa cell translation extracts, and the presence of r3CL(pro) inhibited translation of both endogenous and exogenous mRNAs. Translation inhibition was poly(A) dependent, and replenishment of the extracts with PABP restored translation. Analysis of FCV-infected feline kidney cells showed that the levels of de novo cellular protein synthesis decreased over time as virus-specific proteins accumulated, and cleavage of PABP occurred in virus-infected cells. Our data indicate that the calicivirus 3CL(pro), like PV 3C(pro), mediates the cleavage of PABP as part of its strategy to inhibit cellular translation. PABP cleavage may be a common mechanism among certain virus families to manipulate cellular translation.

  18. Discovery of seven novel Mammalian and avian coronaviruses in the genus deltacoronavirus supports bat coronaviruses as the gene source of alphacoronavirus and betacoronavirus and avian coronaviruses as the gene source of gammacoronavirus and deltacoronavirus.

    Science.gov (United States)

    Woo, Patrick C Y; Lau, Susanna K P; Lam, Carol S F; Lau, Candy C Y; Tsang, Alan K L; Lau, John H N; Bai, Ru; Teng, Jade L L; Tsang, Chris C C; Wang, Ming; Zheng, Bo-Jian; Chan, Kwok-Hung; Yuen, Kwok-Yung

    2012-04-01

    Recently, we reported the discovery of three novel coronaviruses, bulbul coronavirus HKU11, thrush coronavirus HKU12, and munia coronavirus HKU13, which were identified as representatives of a novel genus, Deltacoronavirus, in the subfamily Coronavirinae. In this territory-wide molecular epidemiology study involving 3,137 mammals and 3,298 birds, we discovered seven additional novel deltacoronaviruses in pigs and birds, which we named porcine coronavirus HKU15, white-eye coronavirus HKU16, sparrow coronavirus HKU17, magpie robin coronavirus HKU18, night heron coronavirus HKU19, wigeon coronavirus HKU20, and common moorhen coronavirus HKU21. Complete genome sequencing and comparative genome analysis showed that the avian and mammalian deltacoronaviruses have similar genome characteristics and structures. They all have relatively small genomes (25.421 to 26.674 kb), the smallest among all coronaviruses. They all have a single papain-like protease domain in the nsp3 gene; an accessory gene, NS6 open reading frame (ORF), located between the M and N genes; and a variable number of accessory genes (up to four) downstream of the N gene. Moreover, they all have the same putative transcription regulatory sequence of ACACCA. Molecular clock analysis showed that the most recent common ancestor of all coronaviruses was estimated at approximately 8100 BC, and those of Alphacoronavirus, Betacoronavirus, Gammacoronavirus, and Deltacoronavirus were at approximately 2400 BC, 3300 BC, 2800 BC, and 3000 BC, respectively. From our studies, it appears that bats and birds, the warm blooded flying vertebrates, are ideal hosts for the coronavirus gene source, bats for Alphacoronavirus and Betacoronavirus and birds for Gammacoronavirus and Deltacoronavirus, to fuel coronavirus evolution and dissemination.

  19. Computational modeling of the bat HKU4 coronavirus 3CLpro inhibitors as a tool for the development of antivirals against the emerging Middle East respiratory syndrome (MERS) coronavirus.

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    Abuhammad, Areej; Al-Aqtash, Rua'a A; Anson, Brandon J; Mesecar, Andrew D; Taha, Mutasem O

    2017-11-01

    The Middle East respiratory syndrome coronavirus (MERS-CoV) is an emerging virus that poses a major challenge to clinical management. The 3C-like protease (3CL pro ) is essential for viral replication and thus represents a potential target for antiviral drug development. Presently, very few data are available on MERS-CoV 3CL pro inhibition by small molecules. We conducted extensive exploration of the pharmacophoric space of a recently identified set of peptidomimetic inhibitors of the bat HKU4-CoV 3CL pro . HKU4-CoV 3CL pro shares high sequence identity (81%) with the MERS-CoV enzyme and thus represents a potential surrogate model for anti-MERS drug discovery. We used 2 well-established methods: Quantitative structure-activity relationship (QSAR)-guided modeling and docking-based comparative intermolecular contacts analysis. The established pharmacophore models highlight structural features needed for ligand recognition and revealed important binding-pocket regions involved in 3CL pro -ligand interactions. The best models were used as 3D queries to screen the National Cancer Institute database for novel nonpeptidomimetic 3CL pro inhibitors. The identified hits were tested for HKU4-CoV and MERS-CoV 3CL pro inhibition. Two hits, which share the phenylsulfonamide fragment, showed moderate inhibitory activity against the MERS-CoV 3CL pro and represent a potential starting point for the development of novel anti-MERS agents. To the best of our knowledge, this is the first pharmacophore modeling study supported by in vitro validation on the MERS-CoV 3CL pro . MERS-CoV is an emerging virus that is closely related to the bat HKU4-CoV. 3CL pro is a potential drug target for coronavirus infection. HKU4-CoV 3CL pro is a useful surrogate model for the identification of MERS-CoV 3CL pro enzyme inhibitors. dbCICA is a very robust modeling method for hit identification. The phenylsulfonamide scaffold represents a potential starting point for MERS coronavirus 3CL pro inhibitors

  20. Coronavirus Attachment and Replication

    Science.gov (United States)

    1988-03-28

    has been shown by serologic and virological methods to infect coyotes. Dual infection with canine coronavirus and canine parvovirus causes fatal... attenuation and characteristics of a coronavirus-like agent. Am. J. Vet. Res. 34:145-150. Mebus, C.A., Stair, E.L., Rhodes, M.B., and Twiehaus, M.J. 1973b

  1. Discovery, Synthesis, And Structure-Based Optimization of a Series of N-(tert-Butyl)-2-(N-arylamido)-2-(pyridin-3-yl) Acetamides (ML188) as Potent Noncovalent Small Molecule Inhibitors of the Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) 3CL Protease

    Energy Technology Data Exchange (ETDEWEB)

    Jacobs, Jon [Vanderbilt Univ., Nashville, TN (United States); Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, TN (United States); Grum-Tokars, Valerie [Northwestern Univ., Chicago, IL (United States); Zhou, Ya [Vanderbilt Univ., Nashville, TN (United States); Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, TN (United States); Turlington, Mark [Vanderbilt Univ., Nashville, TN (United States); Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, TN (United States); Saldanha, S. Adrian [Sripps Research Inst. Molecular Screening Center, Jupiter, FL (United States); Chase, Peter [Sripps Research Inst. Molecular Screening Center, Jupiter, FL (United States); Eggler, Aimee [Purdue Univ., West Lafayette, IN (United States); Dawson, Eric S. [Vanderbilt Univ., Nashville, TN (United States); Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, TN (United States); Baez-Santos, Yahira M. [Purdue Univ., West Lafayette, IN (United States); Tomar, Sakshi [Purdue Univ., West Lafayette, IN (United States); Mielech, Anna M. [Loyola Univ. Medical Center, Maywood, IL (United States); Baker, Susan C. [Loyola Univ. Medical Center, Maywood, IL (United States); Lindsley, Craig W. [Vanderbilt Univ., Nashville, TN (United States); Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, TN (United States); Hodder, Peter [Sripps Research Inst. Molecular Screening Center, Jupiter, FL (United States); Mesecar, Andrew [Purdue Univ., West Lafayette, IN (United States); Stauffer, Shaun R. [Vanderbilt Univ., Nashville, TN (United States); Vanderbilt Specialized Chemistry Center for Probe Development (MLPCN), Nashville, TN (United States)

    2012-12-11

    A high-throughput screen of the NIH molecular libraries sample collection and subsequent optimization of a lead dipeptide-like series of severe acute respiratory syndrome (SARS) main protease (3CLpro) inhibitors led to the identification of probe compound ML188 (16-(R), (R)-N-(4-(tert-butyl)phenyl)-N-(2-(tert-butylamino)-2-oxo-1-(pyridin-3-yl)ethyl)furan-2-carboxamide, Pubchem CID: 46897844). But, unlike the majority of reported coronavirus 3CLpro inhibitors that act via covalent modification of the enzyme, 16-(R) is a noncovalent SARS-CoV 3CLpro inhibitor with moderate MW and good enzyme and antiviral inhibitory activity. A multicomponent Ugi reaction was utilized to rapidly explore structure–activity relationships within S1', S1, and S2enzyme binding pockets. Moreover, the X-ray structure of SARS-CoV 3CLpro bound with 16-(R) was instrumental in guiding subsequent rounds of chemistry optimization. 16-(R) provides an excellent starting point for the further design and refinement of 3CLpro inhibitors that act by a noncovalent mechanism of action.

  2. Identification of a new human coronavirus

    NARCIS (Netherlands)

    van der Hoek, Lia; Pyrc, Krzysztof; Jebbink, Maarten F.; Vermeulen-Oost, Wilma; Berkhout, Ron J. M.; Wolthers, Katja C.; Wertheim-van Dillen, Pauline M. E.; Kaandorp, Jos; Spaargaren, Joke; Berkhout, Ben

    2004-01-01

    Three human coronaviruses are known to exist: human coronavirus 229E (HCoV-229E), HCoV-OC43 and severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV). Here we report the identification of a fourth human coronavirus, HCoV-NL63, using a new method of virus discovery. The virus was

  3. Coronavirus spike-receptor interactions

    NARCIS (Netherlands)

    Mou, H.

    2015-01-01

    Coronaviruses cause important diseases in humans and animals. Coronavirus infection starts with the virus binding with its spike proteins to molecules present on the surface of host cells that act as receptors. This spike-receptor interaction is highly specific and determines the virus’ cell, tissue

  4. Involvement of Autophagy in Coronavirus Replication

    Directory of Open Access Journals (Sweden)

    Paul Britton

    2012-11-01

    Full Text Available Coronaviruses are single stranded, positive sense RNA viruses, which induce the rearrangement of cellular membranes upon infection of a host cell. This provides the virus with a platform for the assembly of viral replication complexes, improving efficiency of RNA synthesis. The membranes observed in coronavirus infected cells include double membrane vesicles. By nature of their double membrane, these vesicles resemble cellular autophagosomes, generated during the cellular autophagy pathway. In addition, coronavirus infection has been demonstrated to induce autophagy. Here we review current knowledge of coronavirus induced membrane rearrangements and the involvement of autophagy or autophagy protein microtubule associated protein 1B light chain 3 (LC3 in coronavirus replication.

  5. Human coronavirus NL63, France

    NARCIS (Netherlands)

    Vabret, Astrid; Mourez, Thomas; Dina, Julia; van der Hoek, Lia; Gouarin, Stéphanie; Petitjean, Joëlle; Brouard, Jacques; Freymuth, François

    2005-01-01

    The human coronavirus NL63 (HCoV-NL63) was first identified in The Netherlands, and its circulation in France has not been investigated. We studied HCoV-NL63 infection in hospitalized children diagnosed with respiratory tract infections. From November 2002 to April 2003, we evaluated 300 respiratory

  6. Supermarket Proteases.

    Science.gov (United States)

    Hagar, William G.; Bullerwell, Lornie D.

    2003-01-01

    Presents a laboratory activity on enzymes. Uses common items found in the supermarket that contain protease enzymes, such as contact lens cleaner and meat tenderizer. Demonstrates the digestion of gelatin proteins as part of enzymatic reactions. (Author/SOE)

  7. Earthworm Protease

    Directory of Open Access Journals (Sweden)

    Rong Pan

    2010-01-01

    Full Text Available The alimentary tract of earthworm secretes a group of proteases with a relative wide substrate specificity. In 1983, six isozymes were isolated from earthworm with fibrinolytic activities and called fibriniolytic enzymes. So far, more isozymes have been found from different earthworm species such as Lumbricus rubellus and Eisenia fetida. For convenience, the proteases are named on the basis of the earthworm species and the protein function, for instance, Eisenia fetida protease (EfP. The proteases have the abilities not only to hydrolyze fibrin and other protein, but also activate proenzymes such as plasminogen and prothrombin. In the light of recent studies, eight of the EfPs contain oligosaccharides chains which are thought to support the enzyme structure. Interestingly, EfP-II has a broader substrate specificity presenting alkaline trypsin, chymotrypsin and elastase activities, but EfP-III-1 has a stricter specificity. The protein crystal structures show the characteristics in their specificities. Earthworm proteases have been applied in several areas such as clinical treatment of clotting diseases, anti-tumor study, environmental protection and nutritional production. The current clinical utilizations and some potential new applications of the earthworm protease will be discussed in this paper.

  8. Earthworm Protease

    International Nuclear Information System (INIS)

    Pan, R.; Zhang, Z.; He, R.

    2010-01-01

    The alimentary tract of earthworm secretes a group of proteases with a relative wide substrate specificity. In 1983, six isozymes were isolated from earthworm with fibrinolytic activities and called fibrinolytic enzymes. So far, more isozymes have been found from different earthworm species such as Lumbricus rubellus and Eisenia fetida. For convenience, the proteases are named on the basis of the earthworm species and the protein function, for instance, Eisenia fetida protease (EfP). The proteases have the abilities not only to hydrolyze fibrin and other protein, but also activate pro enzymes such as plasminogen and prothrombin. In the light of recent studies, eight of the EfPs contain oligosaccharides chains which are thought to support the enzyme structure. Interestingly, EfP-II has a broader substrate specificity presenting alkaline trypsin, chymotrypsin and elastase activities, but EfP-III-1 has a stricter specificity. The protein crystal structures show the characteristics in their specificities. Earthworm proteases have been applied in several areas such as clinical treatment of clotting diseases, anti-tumor study, environmental protection and nutritional production. The current clinical utilizations and some potential new applications of the earthworm protease will be discussed in this paper.

  9. Transmission of Middle East respiratory syndrome coronavirus ...

    African Journals Online (AJOL)

    ... hand hygiene, and cough etiquette, would minimize the infection rate among HCPs. The required consumables for maintaining hand hygiene should be readily available to all HCPs. Keywords: Middle East respiratory syndrome coronavirus (MERS-CoV), Systematic review, healthcareassociated infections, Coronaviruses ...

  10. Coronavirus and influenza virus proteolytic priming takes place in tetraspanin-enriched membrane microdomains.

    Science.gov (United States)

    Earnest, James T; Hantak, Michael P; Park, Jung-Eun; Gallagher, Tom

    2015-06-01

    Coronaviruses (CoVs) and low-pathogenicity influenza A viruses (LP IAVs) depend on target cell proteases to cleave their viral glycoproteins and prime them for virus-cell membrane fusion. Several proteases cluster into tetraspanin-enriched microdomains (TEMs), suggesting that TEMs are preferred virus entry portals. Here we found that several CoV receptors and virus-priming proteases were indeed present in TEMs. Isolated TEMs, when mixed with CoV and LP IAV pseudoparticles, cleaved viral fusion proteins to fusion-primed fragments and potentiated viral transductions. That entering viruses utilize TEMs as a protease source was further confirmed using tetraspanin antibodies and tetraspanin short hairpin RNAs (shRNAs). Tetraspanin antibodies inhibited CoV and LP IAV infections, but their virus-blocking activities were overcome by expressing excess TEM-associated proteases. Similarly, cells with reduced levels of the tetraspanin CD9 resisted CoV pseudoparticle transductions but were made susceptible by overproducing TEM-associated proteases. These findings indicated that antibodies and CD9 depletions interfere with viral proteolytic priming in ways that are overcome by surplus proteases. TEMs appear to be exploited by some CoVs and LP IAVs for appropriate coengagement with cell receptors and proteases. Enveloped viruses use their surface glycoproteins to catalyze membrane fusion, an essential cell entry step. Host cell components prime these viral surface glycoproteins to catalyze membrane fusion at specific times and places during virus cell entry. Among these priming components are proteases, which cleave viral surface glycoproteins, unleashing them to refold in ways that catalyze virus-cell membrane fusions. For some enveloped viruses, these proteases are known to reside on target cell surfaces. This research focuses on coronavirus and influenza A virus cell entry and identifies TEMs as sites of viral proteolysis, thereby defining subcellular locations of virus

  11. Processing Proteases

    DEFF Research Database (Denmark)

    Ødum, Anders Sebastian Rosenkrans

    -terminal of the scissile bond, leaving C-terminal fusions to have non-native C-termini after processing. A solution yielding native C-termini would allow novel expression and purification systems for therapeutic proteins and peptides.The peptidyl-Lys metallopeptidase (LysN) of the fungus Armillaria mellea (Am) is one...... of few known proteases to have substrate specificity for the C-terminal side of the scissile bond. LysN exhibits specificity for lysine, and has primarily been used to complement trypsin in to proteomic studies. A working hypothesis during this study was the potential of LysN as a processing protease...

  12. BIOLOGICAL CLONING OF A BOVINE CORONAVIRUS ISOLATE

    OpenAIRE

    Betancourt, A; Rodríguez, Edisleidy; Relova, Damarys; Barrera, Maritza

    2008-01-01

    Con el objetivo de obtener un aislado de Coronavirus bovino clonado biológicamente se adaptó el aislado VB73/04 a la multiplicación en la línea celular MDBK. Este aislado indujo la formación de placas, las cuales resultaron homogéneas después del clonaje biológico. La población viral obtenida fue identificada como Coronavirus bovino por RT-PCR y Seroneutralización. In order to obtain a biologically cloned bovine coronavirus isolate, the isolate VB73/04 was adapted to multiplication in MDBK...

  13. Coronavirus cell entry occurs through the endo-/lysosomal pathway in a proteolysis-dependent manner.

    Directory of Open Access Journals (Sweden)

    Christine Burkard

    2014-11-01

    Full Text Available Enveloped viruses need to fuse with a host cell membrane in order to deliver their genome into the host cell. While some viruses fuse with the plasma membrane, many viruses are endocytosed prior to fusion. Specific cues in the endosomal microenvironment induce conformational changes in the viral fusion proteins leading to viral and host membrane fusion. In the present study we investigated the entry of coronaviruses (CoVs. Using siRNA gene silencing, we found that proteins known to be important for late endosomal maturation and endosome-lysosome fusion profoundly promote infection of cells with mouse hepatitis coronavirus (MHV. Using recombinant MHVs expressing reporter genes as well as a novel, replication-independent fusion assay we confirmed the importance of clathrin-mediated endocytosis and demonstrated that trafficking of MHV to lysosomes is required for fusion and productive entry to occur. Nevertheless, MHV was shown to be less sensitive to perturbation of endosomal pH than vesicular stomatitis virus and influenza A virus, which fuse in early and late endosomes, respectively. Our results indicate that entry of MHV depends on proteolytic processing of its fusion protein S by lysosomal proteases. Fusion of MHV was severely inhibited by a pan-lysosomal protease inhibitor, while trafficking of MHV to lysosomes and processing by lysosomal proteases was no longer required when a furin cleavage site was introduced in the S protein immediately upstream of the fusion peptide. Also entry of feline CoV was shown to depend on trafficking to lysosomes and processing by lysosomal proteases. In contrast, MERS-CoV, which contains a minimal furin cleavage site just upstream of the fusion peptide, was negatively affected by inhibition of furin, but not of lysosomal proteases. We conclude that a proteolytic cleavage site in the CoV S protein directly upstream of the fusion peptide is an essential determinant of the intracellular site of fusion.

  14. Comparative properties of feline coronaviruses in vitro.

    OpenAIRE

    McKeirnan, A J; Evermann, J F; Davis, E V; Ott, R L

    1987-01-01

    Two feline coronaviruses were characterized to determine their biological properties in vitro and their antigenic relatedness to a previously recognized feline infectious peritonitis virus and canine coronavirus. The viruses, designated WSU 79-1146 and WSU 79-1683, were shown to have comparable growth curves with the prototype feline infectious peritonitis virus. Treatment of the feline infectious peritonitis virus strains with 0.25% trypsin indicated that they were relatively resistant to pr...

  15. HTCC: Broad Range Inhibitor of Coronavirus Entry.

    Directory of Open Access Journals (Sweden)

    Aleksandra Milewska

    Full Text Available To date, six human coronaviruses have been known, all of which are associated with respiratory infections in humans. With the exception of the highly pathogenic SARS and MERS coronaviruses, human coronaviruses (HCoV-NL63, HCoV-OC43, HCoV-229E, and HCoV-HKU1 circulate worldwide and typically cause the common cold. In most cases, infection with these viruses does not lead to severe disease, although acute infections in infants, the elderly, and immunocompromised patients may progress to severe disease requiring hospitalization. Importantly, no drugs against human coronaviruses exist, and only supportive therapy is available. Previously, we proposed the cationically modified chitosan, N-(2-hydroxypropyl-3-trimethylammonium chitosan chloride (HTCC, and its hydrophobically-modified derivative (HM-HTCC as potent inhibitors of the coronavirus HCoV-NL63. Here, we show that HTCC inhibits interaction of a virus with its receptor and thus blocks the entry. Further, we demonstrate that HTCC polymers with different degrees of substitution act as effective inhibitors of all low-pathogenic human coronaviruses.

  16. Unraveling the Mysteries of Middle East Respiratory Syndrome Coronavirus

    Centers for Disease Control (CDC) Podcasts

    2014-03-11

    Dr. Aron Hall, a CDC coronavirus epidemiologist, discusses Middle East Respiratory Syndrome Coronavirus.  Created: 3/11/2014 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 3/11/2014.

  17. Discovery of Seven Novel Mammalian and Avian Coronaviruses in the Genus Deltacoronavirus Supports Bat Coronaviruses as the Gene Source of Alphacoronavirus and Betacoronavirus and Avian Coronaviruses as the Gene Source of Gammacoronavirus and Deltacoronavirus

    OpenAIRE

    Woo, Patrick C. Y.; Lau, Susanna K. P.; Lam, Carol S. F.; Lau, Candy C. Y.; Tsang, Alan K. L.; Lau, John H. N.; Bai, Ru; Teng, Jade L. L.; Tsang, Chris C. C.; Wang, Ming; Zheng, Bo-Jian; Chan, Kwok-Hung; Yuen, Kwok-Yung

    2012-01-01

    Recently, we reported the discovery of three novel coronaviruses, bulbul coronavirus HKU11, thrush coronavirus HKU12, and munia coronavirus HKU13, which were identified as representatives of a novel genus, Deltacoronavirus, in the subfamily Coronavirinae. In this territory-wide molecular epidemiology study involving 3,137 mammals and 3,298 birds, we discovered seven additional novel deltacoronaviruses in pigs and birds, which we named porcine coronavirus HKU15, white-eye coronavirus HKU16, sp...

  18. Coronavirus infection, ER stress and Apoptosis

    Directory of Open Access Journals (Sweden)

    TO SING eFUNG

    2014-06-01

    Full Text Available The replication of coronavirus, a family of important animal and human pathogens, is closely associated with the cellular membrane compartments, especially the endoplasmic reticulum (ER. Coronavirus infection of cultured cells was previously shown to cause ER stress and induce the unfolded protein response (UPR, a process that aims to restore the ER homeostasis by global translation shutdown and increasing the ER folding capacity. However under prolonged ER stress, UPR can also induce apoptotic cell death. Accumulating evidence from recent studies has shown that induction of ER stress and UPR may constitute a major aspect of coronavirus-host interaction. Activation of the three branches of UPR modulates a wide variety of signaling pathways, such as mitogen-activated protein (MAP kinases activation, autophagy, apoptosis and innate immune response. ER stress and UPR activation may therefore contribute significantly to the viral replication and pathogenesis during coronavirus infection. In this review, we summarize current knowledge on coronavirus-induced ER stress and UPR activation, with emphasis on their cross-talking to apoptotic signaling.

  19. Feline and canine coronaviruses: common genetic and pathobiological features.

    Science.gov (United States)

    Le Poder, Sophie

    2011-01-01

    A new human coronavirus responsible for severe acute respiratory syndrome (SARS) was identified in 2003, which raised concern about coronaviruses as agents of serious infectious disease. Nevertheless, coronaviruses have been known for about 50 years to be major agents of respiratory, enteric, or systemic infections of domestic and companion animals. Feline and canine coronaviruses are widespread among dog and cat populations, sometimes leading to the fatal diseases known as feline infectious peritonitis (FIP) and pantropic canine coronavirus infection in cats and dogs, respectively. In this paper, different aspects of the genetics, host cell tropism, and pathogenesis of the feline and canine coronaviruses (FCoV and CCoV) will be discussed, with a view to illustrating how study of FCoVs and CCoVs can improve our general understanding of the pathobiology of coronaviruses.

  20. Feline and Canine Coronaviruses: Common Genetic and Pathobiological Features

    Directory of Open Access Journals (Sweden)

    Sophie Le Poder

    2011-01-01

    Full Text Available A new human coronavirus responsible for severe acute respiratory syndrome (SARS was identified in 2003, which raised concern about coronaviruses as agents of serious infectious disease. Nevertheless, coronaviruses have been known for about 50 years to be major agents of respiratory, enteric, or systemic infections of domestic and companion animals. Feline and canine coronaviruses are widespread among dog and cat populations, sometimes leading to the fatal diseases known as feline infectious peritonitis (FIP and pantropic canine coronavirus infection in cats and dogs, respectively. In this paper, different aspects of the genetics, host cell tropism, and pathogenesis of the feline and canine coronaviruses (FCoV and CCoV will be discussed, with a view to illustrating how study of FCoVs and CCoVs can improve our general understanding of the pathobiology of coronaviruses.

  1. An Outbreak of Human Coronavirus OC43 Infection and Serological Cross-Reactivity with SARS Coronavirus

    Directory of Open Access Journals (Sweden)

    David M Patrick

    2006-01-01

    Full Text Available BACKGROUND: In summer 2003, a respiratory outbreak was investigated in British Columbia, during which nucleic acid tests and serology unexpectedly indicated reactivity for severe acute respiratory syndrome coronavirus (SARS-CoV.

  2. Human monoclonal antibody as prophylaxis for SARS coronavirus infection in ferrets

    NARCIS (Netherlands)

    ter Meulen, Jan; Bakker, Alexander B. H.; van den Brink, Edward N.; Weverling, Gerrit J.; Martina, Byron E. E.; Haagmans, Bart L.; Kuiken, Thijs; de Kruif, John; Preiser, Wolfgang; Spaan, Willy; Gelderblom, Hans R.; Goudsmit, Jaap; Osterhaus, Albert D. M. E.

    2004-01-01

    SARS coronavirus continues to cause sporadic cases of severe acute respiratory syndrome (SARS) in China. No active or passive immunoprophylaxis for disease induced by SARS coronavirus is available. We investigated prophylaxis of SARS coronavirus infection with a neutralising human monoclonal

  3. Proteolytic activation of the SARS-coronavirus spike protein: cutting enzymes at the cutting edge of antiviral research.

    Science.gov (United States)

    Simmons, Graham; Zmora, Pawel; Gierer, Stefanie; Heurich, Adeline; Pöhlmann, Stefan

    2013-12-01

    The severe acute respiratory syndrome (SARS) pandemic revealed that zoonotic transmission of animal coronaviruses (CoV) to humans poses a significant threat to public health and warrants surveillance and the development of countermeasures. The activity of host cell proteases, which cleave and activate the SARS-CoV spike (S) protein, is essential for viral infectivity and constitutes a target for intervention. However, the identities of the proteases involved have been unclear. Pioneer studies identified cathepsins and type II transmembrane serine proteases as cellular activators of SARS-CoV and demonstrated that several emerging viruses might exploit these enzymes to promote their spread. Here, we will review the proteolytic systems hijacked by SARS-CoV for S protein activation, we will discuss their contribution to viral spread in the host and we will outline antiviral strategies targeting these enzymes. This paper forms part of a series of invited articles in Antiviral Research on "From SARS to MERS: 10years of research on highly pathogenic human coronaviruses.'' Copyright © 2013 Elsevier B.V. All rights reserved.

  4. MERS-coronavirus: From discovery to intervention

    NARCIS (Netherlands)

    W. Widagdo; N.M.A. Okba (Nisreen); V. Stalin Raj; B.L. Haagmans (Bart)

    2017-01-01

    textabstractMiddle East respiratory syndrome coronavirus (MERS-CoV) still causes outbreaks despite public awareness and implementation of health care measures, such as rapid viral diagnosis and patient quarantine. Here we describe the current epidemiological picture of MERS-CoV, focusing on humans

  5. Coronavirus infection of polarized epithelial cells

    NARCIS (Netherlands)

    Rossen, J W; Horzinek, M C; Rottier, P J

    1995-01-01

    Epithelial cells are the first host cells to be infected by incoming c oronaviruses. Recent observations in vitro show that coronaviruses are released from a specific side of these polarized cells, and this polarized release might be important for the spread of the infection in vivo. Mechanisms for

  6. Dynamics of the coronavirus replicative structures

    NARCIS (Netherlands)

    Hagemeijer, M.C.

    2011-01-01

    Coronaviruses (CoV) are positive-strand RNA (+RNA) viruses that are important infectious agents in both animals and man. Upon infection, CoVs generate large multicomponent protein complexes, consisting of 16 nonstructural proteins (nsp’s) and yet to be identified cellular proteins, dedicated to the

  7. Suppression of Coronavirus Replication by Cyclophilin Inhibitors

    Directory of Open Access Journals (Sweden)

    Takashi Sasaki

    2013-05-01

    Full Text Available Coronaviruses infect a variety of mammalian and avian species and cause serious diseases in humans, cats, mice, and birds in the form of severe acute respiratory syndrome (SARS, feline infectious peritonitis (FIP, mouse hepatitis, and avian infectious bronchitis, respectively. No effective vaccine or treatment has been developed for SARS-coronavirus or FIP virus, both of which cause lethal diseases. It has been reported that a cyclophilin inhibitor, cyclosporin A (CsA, could inhibit the replication of coronaviruses. CsA is a well-known immunosuppressive drug that binds to cellular cyclophilins to inhibit calcineurin, a calcium-calmodulin-activated serine/threonine-specific phosphatase. The inhibition of calcineurin blocks the translocation of nuclear factor of activated T cells from the cytosol into the nucleus, thus preventing the transcription of genes encoding cytokines such as interleukin-2. Cyclophilins are peptidyl-prolyl isomerases with physiological functions that have been described for many years to include chaperone and foldase activities. Also, many viruses require cyclophilins for replication; these include human immunodeficiency virus, vesicular stomatitis virus, and hepatitis C virus. However, the molecular mechanisms leading to the suppression of viral replication differ for different viruses. This review describes the suppressive effects of CsA on coronavirus replication.

  8. Canine coronaviruses: Epidemiology, evolution and pathobiology

    NARCIS (Netherlands)

    Decaro, N.

    2009-01-01

    Coronaviruses (CoVs; order Nidovirales, family Coronaviridae) are viruses exceptionally prone to genetic evolution through the continual accumulation of mutations and by homologous recombination between related members. CoVs are organised into three antigenic groups of which group 1 is subdivided in

  9. Coronavirus infections in horses in Saudi Arabia and Oman.

    Science.gov (United States)

    Hemida, M G; Chu, D K W; Perera, R A P M; Ko, R L W; So, R T Y; Ng, B C Y; Chan, S M S; Chu, S; Alnaeem, A A; Alhammadi, M A; Webby, R J; Poon, L L M; Balasuriya, U B R; Peiris, M

    2017-12-01

    Equine coronaviruses (ECoV) are the only coronavirus known to infect horses. So far, data on ECoV infection in horses remain limited to the USA, France and Japan and its geographic distribution is not well understood. We carried out RT-PCR on 306 nasal and 315 rectal swabs and tested 243 sera for antibodies to detect coronavirus infections in apparently healthy horses in Saudi Arabia and Oman. We document evidence of infection with ECoV and HKU23 coronavirus by RT-PCR. There was no conclusive evidence of Middle East respiratory syndrome coronavirus infection in horses. Serological data suggest that lineage A betacoronavirus infections are commonly infecting horses in Saudi Arabia and Oman but antibody cross-reactivities between these viruses do not permit us to use serological data alone to identify which coronaviruses are causing these infections. © 2017 Blackwell Verlag GmbH.

  10. Feline coronavirus type II strains 79-1683 and 79-1146 originate from a double recombination between feline coronavirus type I and canine coronavirus

    NARCIS (Netherlands)

    Horzinek, M.C.; Herrewegh, A.A.; Rottier, P.J.M.; Groot, R.J. de

    1998-01-01

    Recent evidence suggests that the type II feline coronavirus (FCoV) strains 79-1146 and 79-1683 have arisen from a homologous RNA recombination event between FCoV type I and canine coronavirus (CCV). In both cases, the template switch apparently took place between the S and M genes, giving rise to

  11. Preliminary crystallographic analysis of avian infectious bronchitis virus main protease

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jun; Shen, Wei [Laboratory of Structural Biology, Tsinghua University, Beijing 100084 (China); Liao, Ming, E-mail: mliao@scau.edu.cn [Laboratory of Avian Medicine, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642 (China); Bartlam, Mark, E-mail: mliao@scau.edu.cn [Laboratory of Structural Biology, Tsinghua University, Beijing 100084 (China); National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101 (China)

    2007-01-01

    The avian infectious bronchitis virus main protease has been crystallized; crystals diffract to 2.7 Å resolution. Infectious bronchitis virus (IBV) is the prototype of the genus Coronavirus. It causes a highly contagious disease which affects the respiratory, reproductive, neurological and renal systems of chickens, resulting great economic losses in the poultry industry worldwide. The coronavirus (CoV) main protease (M{sup pro}), which plays a pivotal role in viral gene expression and replication through a highly complex cascade involving the proteolytic processing of replicase polyproteins, is an attractive target for antiviral drug design. In this study, IBV M{sup pro} was overexpressed in Escherichia coli. Crystals suitable for X-ray crystallography have been obtained using microseeding techniques and belong to space group P6{sub 1}22. X-ray diffraction data were collected in-house to 2.7 Å resolution from a single crystal. The unit-cell parameters were a = b = 119.1, c = 270.7 Å, α = β = 90, γ = 120°. Three molecules were predicted to be present in the asymmetric unit from a calculated self-rotation function.

  12. Coronavirus Infection and Diversity in Bats in the Australasian Region.

    Science.gov (United States)

    Smith, C S; de Jong, C E; Meers, J; Henning, J; Wang, L- F; Field, H E

    2016-03-01

    Following the SARS outbreak, extensive surveillance was undertaken globally to detect and identify coronavirus diversity in bats. This study sought to identify the diversity and prevalence of coronaviruses in bats in the Australasian region. We identified four different genotypes of coronavirus, three of which (an alphacoronavirus and two betacoronaviruses) are potentially new species, having less than 90% nucleotide sequence identity with the most closely related described viruses. We did not detect any SARS-like betacoronaviruses, despite targeting rhinolophid bats, the putative natural host taxa. Our findings support the virus-host co-evolution hypothesis, with the detection of Miniopterus bat coronavirus HKU8 (previously reported in Miniopterus species in China, Hong Kong and Bulgaria) in Australian Miniopterus species. Similarly, we detected a novel betacoronavirus genotype from Pteropus alecto which is most closely related to Bat coronavirus HKU9 identified in other pteropodid bats in China, Kenya and the Philippines. We also detected possible cross-species transmission of bat coronaviruses, and the apparent enteric tropism of these viruses. Thus, our findings are consistent with a scenario wherein the current diversity and host specificity of coronaviruses reflects co-evolution with the occasional host shift.

  13. Genetic Characteristics of Coronaviruses from Korean Bats in 2016.

    Science.gov (United States)

    Lee, Saemi; Jo, Seong-Deok; Son, Kidong; An, Injung; Jeong, Jipseol; Wang, Seung-Jun; Kim, Yongkwan; Jheong, Weonhwa; Oem, Jae-Ku

    2018-01-01

    Bats have increasingly been recognized as the natural reservoir of severe acute respiratory syndrome (SARS), coronavirus, and other coronaviruses found in mammals. However, little research has been conducted on bat coronaviruses in South Korea. In this study, bat samples (332 oral swabs, 245 fecal samples, 38 urine samples, and 57 bat carcasses) were collected at 33 natural bat habitat sites in South Korea. RT-PCR and sequencing were performed for specific coronavirus genes to identify the bat coronaviruses in different bat samples. Coronaviruses were detected in 2.7% (18/672) of the samples: 13 oral swabs from one species of the family Rhinolophidae, and four fecal samples and one carcass (intestine) from three species of the family Vespertiliodae. To determine the genetic relationships of the 18 sequences obtained in this study and previously known coronaviruses, the nucleotide sequences of a 392-nt region of the RNA-dependent RNA polymerase (RdRp) gene were analyzed phylogenetically. Thirteen sequences belonging to SARS-like betacoronaviruses showed the highest nucleotide identity (97.1-99.7%) with Bat-CoV-JTMC15 reported in China. The other five sequences were most similar to MERS-like betacoronaviruses. Four nucleotide sequences displayed the highest identity (94.1-95.1%) with Bat-CoV-HKU5 from Hong Kong. The one sequence from a carcass showed the highest nucleotide identity (99%) with Bat-CoV-SC2013 from China. These results suggest that careful surveillance of coronaviruses from bats should be continued, because animal and human infections may result from the genetic variants present in bat coronavirus reservoirs.

  14. Bacterial proteases and virulence

    DEFF Research Database (Denmark)

    Frees, Dorte; Brøndsted, Lone; Ingmer, Hanne

    2013-01-01

    signalling to short-circuit host cell processes. Common to both intra- and extracellular proteases is the tight control of their proteolytic activities. In general, substrate recognition by the intracellular proteases is highly selective which is, in part, attributed to the chaperone activity associated...... tolerance to adverse conditions such as those experienced in the host. In the membrane, HtrA performs similar functions whereas the extracellular proteases, in close contact with host components, pave the way for spreading infections by degrading host matrix components or interfering with host cell...... with the proteases either encoded within the same polypeptide or on separate subunits. In contrast, substrate recognition by extracellular proteases is less selective and therefore these enzymes are generally expressed as zymogens to prevent premature proteolytic activity that would be detrimental to the cell...

  15. Diagnostic Methods for Feline Coronavirus: A Review

    Directory of Open Access Journals (Sweden)

    Saeed Sharif

    2010-01-01

    Full Text Available Feline coronaviruses (FCoVs are found throughout the world. Infection with FCoV can result in a diverse range of signs from clinically inapparent infections to a highly fatal disease called feline infectious peritonitis (FIP. FIP is one of the most serious viral diseases of cats. While there is neither an effective vaccine, nor a curative treatment for FIP, a diagnostic protocol for FCoV would greatly assist in the management and control of the virus. Clinical findings in FIP are non-specific and not helpful in making a differential diagnosis. Haematological and biochemical abnormalities in FIP cases are also non-specific. The currently available serological tests have low specificity and sensitivity for detection of active infection and cross-react with FCoV strains of low pathogenicity, the feline enteric coronaviruses (FECV. Reverse transcriptase polymerase chain reaction (RT-PCR has been used to detect FCoV and is rapid and sensitive, but results must be interpreted in the context of clinical findings. At present, a definitive diagnosis of FIP can be established only by histopathological examination of biopsies. This paper describes and compares diagnostic methods for FCoVs and includes a brief account of the virus biology, epidemiology, and pathogenesis.

  16. Antibody response to equine coronavirus in horses inoculated with a bovine coronavirus vaccine.

    Science.gov (United States)

    Nemoto, Manabu; Kanno, Toru; Bannai, Hiroshi; Tsujimura, Koji; Yamanaka, Takashi; Kokado, Hiroshi

    2017-11-17

    A vaccine for equine coronavirus (ECoV) is so far unavailable. Bovine coronavirus (BCoV) is antigenically related to ECoV; it is therefore possible that BCoV vaccine will induce antibodies against ECoV in horses. This study investigated antibody response to ECoV in horses inoculated with BCoV vaccine. Virus neutralization tests showed that antibody titers against ECoV increased in all six horses tested at 14 days post inoculation, although the antibody titers were lower against ECoV than against BCoV. This study showed that BCoV vaccine provides horses with antibodies against ECoV to some extent. It is unclear whether antibodies provided by BCoV vaccine are effective against ECoV, and therefore ECoV challenge studies are needed to evaluate efficacy of the vaccine in the future.

  17. Coronavirus 229E-related pneumonia in immunocompromised patients.

    Science.gov (United States)

    Pene, Frédéric; Merlat, Annabelle; Vabret, Astrid; Rozenberg, Flore; Buzyn, Agnès; Dreyfus, François; Cariou, Alain; Freymuth, François; Lebon, Pierre

    2003-10-01

    Coronaviruses strains 229E and OC43 have been associated with various respiratory illnesses ranging from the self-resolving common cold to severe pneumonia. Although chronic underlying conditions are major determinants of severe respiratory virus infections, few data about coronavirus-related pneumonia in immunocompromised patients are available. Here we report 2 well-documented cases of pneumonia related to coronavirus 229E, each with a different clinical presentation. Diagnosis was made on the basis of viral culture and electron microscopy findings that exhibited typical crown-like particles and through amplification of the viral genome by reverse transcriptase-polymerase chain reaction. On the basis of this report, coronaviruses should be considered as potential causative microorganisms of pneumonia in immunocompromised patients.

  18. Molecular and pathological identification of feline coronavirus type I

    African Journals Online (AJOL)

    DR. NJ TONUKARI

    2012-06-05

    Jun 5, 2012 ... In this study, we described the isolation and molecular characterization of .... fecv2b) designed in the regions of S-protein gene were used to differentiate ..... The molecular dynamics of feline coronaviruses. Vet. Microbiol.

  19. Spike Protein Fusion Peptide and Feline Coronavirus Virulence

    Science.gov (United States)

    Chang, Hui-Wen; Egberink, Herman F.; Halpin, Rebecca; Spiro, David J.

    2012-01-01

    Coronaviruses are well known for their potential to change their host or tissue tropism, resulting in unpredictable new diseases and changes in pathogenicity; severe acute respiratory syndrome and feline coronaviruses, respectively, are the most recognized examples. Feline coronaviruses occur as 2 pathotypes: nonvirulent feline enteric coronaviruses (FECVs), which replicate in intestinal epithelium cells, and lethal feline infectious peritonitis viruses (FIPVs), which replicate in macrophages. Evidence indicates that FIPV originates from FECV by mutation, but consistent distinguishing differences have not been established. We sequenced the full genome of 11 viruses of each pathotype and then focused on the single most distinctive site by additionally sequencing hundreds of viruses in that region. As a result, we identified 2 alternative amino acid differences in the putative fusion peptide of the spike protein that together distinguish FIPV from FECV in >95% of cases. By these and perhaps other mutations, the virus apparently acquires its macrophage tropism and spreads systemically. PMID:22709821

  20. Modelling of potentially promising SARS protease inhibitors

    International Nuclear Information System (INIS)

    Plewczynski, Dariusz; Hoffmann, Marcin; Grotthuss, Marcin von; Knizewski, Lukasz; Rychewski, Leszek; Eitner, Krystian; Ginalski, Krzysztof

    2007-01-01

    In many cases, at the beginning of a high throughput screening experiment some information about active molecules is already available. Active compounds (such as substrate analogues, natural products and inhibitors of related proteins) are often identified in low throughput validation studies on a biochemical target. Sometimes the additional structural information is also available from crystallographic studies on protein and ligand complexes. In addition, the structural or sequence similarity of various protein targets yields a novel possibility for drug discovery. Co-crystallized compounds from homologous proteins can be used to design leads for a new target without co-crystallized ligands. In this paper we evaluate how far such an approach can be used in a real drug campaign, with severe acute respiratory syndrome (SARS) coronavirus providing an example. Our method is able to construct small molecules as plausible inhibitors solely on the basis of the set of ligands from crystallized complexes of a protein target, and other proteins from its structurally homologous family. The accuracy and sensitivity of the method are estimated here by the subsequent use of an electronic high throughput screening flexible docking algorithm. The best performing ligands are then used for a very restrictive similarity search for potential inhibitors of the SARS protease within the million compounds from the Ligand.Info small molecule meta-database. The selected molecules can be passed on for further experimental validation

  1. Modelling of potentially promising SARS protease inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Plewczynski, Dariusz [Interdisciplinary Centre for Mathematical and Computational Modelling, ICM, Warsaw University, Pawinskiego 5a Street, 02-106 Warsaw (Poland); Hoffmann, Marcin [BioInfoBank Institute, Limanowskiego 24A/16, 60-744 Poznan (Poland); Grotthuss, Marcin von [BioInfoBank Institute, Limanowskiego 24A/16, 60-744 Poznan (Poland); Knizewski, Lukasz [Interdisciplinary Centre for Mathematical and Computational Modelling, ICM, Warsaw University, Pawinskiego 5a Street, 02-106 Warsaw (Poland); Rychewski, Leszek [BioInfoBank Institute, Limanowskiego 24A/16, 60-744 Poznan (Poland); Eitner, Krystian [BioInfoBank Institute, Limanowskiego 24A/16, 60-744 Poznan (Poland); Ginalski, Krzysztof [Interdisciplinary Centre for Mathematical and Computational Modelling, ICM, Warsaw University, Pawinskiego 5a Street, 02-106 Warsaw (Poland)

    2007-07-18

    In many cases, at the beginning of a high throughput screening experiment some information about active molecules is already available. Active compounds (such as substrate analogues, natural products and inhibitors of related proteins) are often identified in low throughput validation studies on a biochemical target. Sometimes the additional structural information is also available from crystallographic studies on protein and ligand complexes. In addition, the structural or sequence similarity of various protein targets yields a novel possibility for drug discovery. Co-crystallized compounds from homologous proteins can be used to design leads for a new target without co-crystallized ligands. In this paper we evaluate how far such an approach can be used in a real drug campaign, with severe acute respiratory syndrome (SARS) coronavirus providing an example. Our method is able to construct small molecules as plausible inhibitors solely on the basis of the set of ligands from crystallized complexes of a protein target, and other proteins from its structurally homologous family. The accuracy and sensitivity of the method are estimated here by the subsequent use of an electronic high throughput screening flexible docking algorithm. The best performing ligands are then used for a very restrictive similarity search for potential inhibitors of the SARS protease within the million compounds from the Ligand.Info small molecule meta-database. The selected molecules can be passed on for further experimental validation.

  2. European Surveillance for Pantropic Canine Coronavirus

    Science.gov (United States)

    Cordonnier, Nathalie; Demeter, Zoltan; Egberink, Herman; Elia, Gabriella; Grellet, Aurélien; Le Poder, Sophie; Mari, Viviana; Martella, Vito; Ntafis, Vasileios; von Reitzenstein, Marcela; Rottier, Peter J.; Rusvai, Miklos; Shields, Shelly; Xylouri, Eftychia; Xu, Zach; Buonavoglia, Canio

    2013-01-01

    Highly virulent pantropic canine coronavirus (CCoV) strains belonging to subtype IIa were recently identified in dogs. To assess the distribution of such strains in Europe, tissue samples were collected from 354 dogs that had died after displaying systemic disease in France (n = 92), Hungary (n = 75), Italy (n = 69), Greece (n = 87), The Netherlands (n = 27), Belgium (n = 4), and Bulgaria (n = 1). A total of 124 animals tested positive for CCoV, with 33 of them displaying the virus in extraintestinal tissues. Twenty-four CCoV strains (19.35% of the CCoV-positive dogs) detected in internal organs were characterized as subtype IIa and consequently assumed to be pantropic CCoVs. Sequence and phylogenetic analyses of the 5′ end of the spike protein gene showed that pantropic CCoV strains are closely related to each other, with the exception of two divergent French viruses that clustered with enteric strains. PMID:23100349

  3. Feline Coronaviruses: Pathogenesis of Feline Infectious Peritonitis.

    Science.gov (United States)

    Tekes, G; Thiel, H-J

    2016-01-01

    Feline infectious peritonitis (FIP) belongs to the few animal virus diseases in which, in the course of a generally harmless persistent infection, a virus acquires a small number of mutations that fundamentally change its pathogenicity, invariably resulting in a fatal outcome. The causative agent of this deadly disease, feline infectious peritonitis virus (FIPV), arises from feline enteric coronavirus (FECV). The review summarizes our current knowledge of the genome and proteome of feline coronaviruses (FCoVs), focusing on the viral surface (spike) protein S and the five accessory proteins. We also review the current classification of FCoVs into distinct serotypes and biotypes, cellular receptors of FCoVs and their presumed role in viral virulence, and discuss other aspects of FIPV-induced pathogenesis. Our current knowledge of genetic differences between FECVs and FIPVs has been mainly based on comparative sequence analyses that revealed "discriminatory" mutations that are present in FIPVs but not in FECVs. Most of these mutations result in amino acid substitutions in the S protein and these may have a critical role in the switch from FECV to FIPV. In most cases, the precise roles of these mutations in the molecular pathogenesis of FIP have not been tested experimentally in the natural host, mainly due to the lack of suitable experimental tools including genetically engineered virus mutants. We discuss the recent progress in the development of FCoV reverse genetics systems suitable to generate recombinant field viruses containing appropriate mutations for in vivo studies. © 2016 Elsevier Inc. All rights reserved.

  4. Emergence of pathogenic coronaviruses in cats by homologous recombination between feline and canine coronaviruses.

    Directory of Open Access Journals (Sweden)

    Yutaka Terada

    Full Text Available Type II feline coronavirus (FCoV emerged via double recombination between type I FCoV and type II canine coronavirus (CCoV. In this study, two type I FCoVs, three type II FCoVs and ten type II CCoVs were genetically compared. The results showed that three Japanese type II FCoVs, M91-267, KUK-H/L and Tokyo/cat/130627, also emerged by homologous recombination between type I FCoV and type II CCoV and their parent viruses were genetically different from one another. In addition, the 3'-terminal recombination sites of M91-267, KUK-H/L and Tokyo/cat/130627 were different from one another within the genes encoding membrane and spike proteins, and the 5'-terminal recombination sites were also located at different regions of ORF1. These results indicate that at least three Japanese type II FCoVs emerged independently. Sera from a cat experimentally infected with type I FCoV was unable to neutralize type II CCoV infection, indicating that cats persistently infected with type I FCoV may be superinfected with type II CCoV. Our previous study reported that few Japanese cats have antibody against type II FCoV. All of these observations suggest that type II FCoV emerged inside the cat body and is unable to readily spread among cats, indicating that these recombination events for emergence of pathogenic coronaviruses occur frequently.

  5. Recombination in Avian Gamma-Coronavirus Infectious Bronchitis Virus

    Directory of Open Access Journals (Sweden)

    Mark W. Jackwood

    2011-09-01

    Full Text Available Recombination in the family Coronaviridae has been well documented and is thought to be a contributing factor in the emergence and evolution of different coronaviral genotypes as well as different species of coronavirus. However, there are limited data available on the frequency and extent of recombination in coronaviruses in nature and particularly for the avian gamma-coronaviruses where only recently the emergence of a turkey coronavirus has been attributed solely to recombination. In this study, the full-length genomes of eight avian gamma-coronavirus infectious bronchitis virus (IBV isolates were sequenced and along with other full-length IBV genomes available from GenBank were analyzed for recombination. Evidence of recombination was found in every sequence analyzed and was distributed throughout the entire genome. Areas that have the highest occurrence of recombination are located in regions of the genome that code for nonstructural proteins 2, 3 and 16, and the structural spike glycoprotein. The extent of the recombination observed, suggests that this may be one of the principal mechanisms for generating genetic and antigenic diversity within IBV. These data indicate that reticulate evolutionary change due to recombination in IBV, likely plays a major role in the origin and adaptation of the virus leading to new genetic types and strains of the virus.

  6. A molecular arms race between host innate antiviral response and emerging human coronaviruses.

    Science.gov (United States)

    Wong, Lok-Yin Roy; Lui, Pak-Yin; Jin, Dong-Yan

    2016-02-01

    Coronaviruses have been closely related with mankind for thousands of years. Community-acquired human coronaviruses have long been recognized to cause common cold. However, zoonotic coronaviruses are now becoming more a global concern with the discovery of highly pathogenic severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) coronaviruses causing severe respiratory diseases. Infections by these emerging human coronaviruses are characterized by less robust interferon production. Treatment of patients with recombinant interferon regimen promises beneficial outcomes, suggesting that compromised interferon expression might contribute at least partially to the severity of disease. The mechanisms by which coronaviruses evade host innate antiviral response are under intense investigations. This review focuses on the fierce arms race between host innate antiviral immunity and emerging human coronaviruses. Particularly, the host pathogen recognition receptors and the signal transduction pathways to mount an effective antiviral response against SARS and MERS coronavirus infection are discussed. On the other hand, the counter-measures evolved by SARS and MERS coronaviruses to circumvent host defense are also dissected. With a better understanding of the dynamic interaction between host and coronaviruses, it is hoped that insights on the pathogenesis of newly-identified highly pathogenic human coronaviruses and new strategies in antiviral development can be derived.

  7. Coronaviruses in brain tissue from patients with multiple sclerosis

    DEFF Research Database (Denmark)

    Dessau, R B; Lisby, G; Frederiksen, J L

    2001-01-01

    Brain tissue from 25 patients with clinically definite multiple sclerosis (MS) and as controls brain tissue from 36 patients without neurological disease was tested for the presence of human coronaviral RNA. Four PCR assays with primers specific for N-protein of human coronavirus strain 229E...... and three PCR assays with primers specific for the nucleocapsid protein of human coronavirus strain OC43 were performed. Sporadic positive PCR assays were observed in both patients and controls in some of the PCR assays. However, these results were not reproducible and there was no difference...... in the proportion of positive signals from the MS patients compared to controls. Evidence for a chronic infection with the human coronaviruses strain 229E or OC43 in brain tissue from patients with MS or controls has not been found in this study....

  8. Genotyping coronaviruses associated with feline infectious peritonitis.

    Science.gov (United States)

    Lewis, Catherine S; Porter, Emily; Matthews, David; Kipar, Anja; Tasker, Séverine; Helps, Christopher R; Siddell, Stuart G

    2015-06-01

    Feline coronavirus (FCoV) infections are endemic among cats worldwide. The majority of infections are asymptomatic or result in only mild enteric disease. However, approximately 5 % of cases develop feline infectious peritonitis (FIP), a systemic disease that is a frequent cause of death in young cats. In this study, we report the complete coding genome sequences of six FCoVs: three from faecal samples from healthy cats and three from tissue lesion samples from cats with confirmed FIP. The six samples were obtained over a period of 8 weeks at a single-site cat rescue and rehoming centre in the UK. We found amino acid differences located at 44 positions across an alignment of the six virus translatomes and, at 21 of these positions, the differences fully or partially discriminated between the genomes derived from the faecal samples and the genomes derived from the tissue lesion samples. In this study, two amino acid differences fully discriminated the two classes of genomes: these were both located in the S2 domain of the virus surface glycoprotein gene. We also identified deletions in the 3c protein ORF of genomes from two of the FIP samples. Our results support previous studies that implicate S protein mutations in the pathogenesis of FIP. © 2015 The Authors.

  9. Nucleic Acid Aptamers Against Proteases

    DEFF Research Database (Denmark)

    Dupont, D M; Andersen, L M; Bøtkjær, Kenneth Alrø

    2011-01-01

    , directed against blood coagulation factors, are in clinical trials as anticoagulant drugs. Several of the studies on protease-binding aptamers have been pioneering and trend-setting in the field. The work with protease-binding aptamers also demonstrates many interesting examples of non-standard selection......Proteases are potential or realized therapeutic targets in a wide variety of pathological conditions. Moreover, proteases are classical subjects for studies of enzymatic and regulatory mechanisms. We here review the literature on nucleic acid aptamers selected with proteases as targets. Designing...... small molecule protease inhibitors of sufficient specificity has proved a daunting task. Aptamers seem to represent a promising alternative. In our review, we concentrate on biochemical mechanisms of aptamer selection, proteinaptamer recognition, protease inhibition, and advantages of aptamers...

  10. Discovery of novel bat coronaviruses in south China that use the same receptor as MERS coronavirus.

    Science.gov (United States)

    Luo, Chu-Ming; Wang, Ning; Yang, Xing-Lou; Liu, Hai-Zhou; Zhang, Wei; Li, Bei; Hu, Ben; Peng, Cheng; Geng, Qi-Bin; Zhu, Guang-Jian; Li, Fang; Shi, Zheng-Li

    2018-04-18

    Middle East respiratory syndrome coronavirus (MERS-CoV) has represented a human health threat since 2012. Although several MERS-related CoVs, which belong to the same species as MERS-CoV, have been identified from bats, they do not use the MERS-CoV receptor, dipeptidyl peptidase 4 (DPP4). Here, we screened 1059 bat samples from at least 30 bat species collected in different regions in south China and identified 89 strains of lineage C betacoronaviruses, including Tylonycteris pachypus HKU4 , Pipistrellus pipistrellus HKU5, and MERS-related CoVs. We sequenced the full-length genomes of two positive samples collected from the great evening bat, Ia io , from Guangdong Province. The two genomes were highly similar and exhibited genomic structures identical to those of other lineage C betacoronaviruses. While they exhibited genome-wide nucleotide identities of only 75.3 to 81.2% with other MERS-related CoVs, their gene-coding regions were highly similar to their counterparts, except in the case of the spike proteins. Further protein--protein interaction assays demonstrated that the spike proteins of these MERS-related CoVs bind to the receptor DPP4. Recombination analysis suggested that the newly discovered MERS-related CoVs might have acquired their spike genes from a DPP4-recognizing bat HKU4. Our study provides further evidence that bats represent the evolutionary origins of MERS-CoV. IMPORTANCE Previous studies suggested that the Middle East respiratory syndrome coronavirus (MERS-CoV) may have originated in bats. However, its evolutionary path from bats to humans remains unclear. In this study, we discovered 89 novel lineage C betacoronaviruses (BetaCoVs) in eight bat species. We provide the evidence of a MERS-related CoV derived from the great evening bat that uses the same host receptor as human MERS-CoV. This virus also provides evidence for a natural recombination event between the bat MERS-related CoV and another bat coronavirus HKU4. Our study expands the host

  11. [Nosocomial infections due to human coronaviruses in the newborn].

    Science.gov (United States)

    Gagneur, A; Legrand, M C; Picard, B; Baron, R; Talbot, P J; de Parscau, L; Sizun, J

    2002-01-01

    Human coronaviruses, with two known serogroups named 229-E and OC-43, are enveloped positive-stranded RNA viruses. The large RNA is surrounded by a nucleoprotein (protein N). The envelop contains 2 or 3 glycoproteins: spike protein (or protein S), matrix protein (or protein M) and a hemagglutinin (or protein HE). Their pathogen role remains unclear because their isolation is difficult. Reliable and rapid methods as immunofluorescence with monoclonal antibodies and reverse transcription-polymerase chain reaction allow new researches on epidemiology. Human coronaviruses can survive for as long as 6 days in suspension and 3 hours after drying on surfaces, suggesting that they could be a source of hospital-acquired infections. Two prospective studies conducted in a neonatal and paediatric intensive care unit demonstrated a significant association of coronavirus-positive nasopharyngal samples with respiratory illness in hospitalised preterm neonates. Positive samples from staff suggested either a patient-to-staff or a staff-to-patient transmission. No cross-infection were observed from community-acquired respiratory-syncitial virus or influenza-infected children to neonates. Universal precautions with hand washing and surface desinfection could be proposed to prevent coronavirus transmission.

  12. Cross host transmission in the emergence of MERS coronavirus

    NARCIS (Netherlands)

    C.B.E.M. Reusken (Chantal); V.S. Raj (Stalin); M.P.G. Koopmans D.V.M. (Marion); B.L. Haagmans (Bart)

    2016-01-01

    textabstractCoronaviruses (CoVs) able to infect humans emerge through cross-host transmission from animals. There is substantial evidence that the recent Middle East respiratory syndrome (MERS)-CoV outbreak is fueled by zoonotic transmission from dromedary camels. This is largely based on the fact

  13. Tissue Distribution of the MERS-Coronavirus Receptor in Bats

    NARCIS (Netherlands)

    W. Widagdo; L. Begeman (Lineke); D. Schipper (Debby); P.R.W.A. van Run (Peter); Cunningham, A.A. (Andrew A); Kley, N. (Nils); C.B.E.M. Reusken (Chantal); B.L. Haagmans (Bart); J.M.A. van den Brand (Judith)

    2017-01-01

    textabstractMiddle East respiratory syndrome coronavirus (MERS-CoV) has been shown to infect both humans and dromedary camels using dipeptidyl peptidase-4 (DPP4) as its receptor.The distribution of DPP4 in the respiratory tract tissues of humans and camels reflects MERS-CoV tropism.Apart from

  14. Tissue Distribution of the MERS-Coronavirus Receptor in Bats

    NARCIS (Netherlands)

    Widagdo, W; Begeman, Lineke; Schipper, Debby; van Run, Peter R; Cunningham, Andrew A; Kley, Nils; Reusken, Chantal B E M; Haagmans, Bart L; van den Brand, Judith M A

    2017-01-01

    Middle East respiratory syndrome coronavirus (MERS-CoV) has been shown to infect both humans and dromedary camels using dipeptidyl peptidase-4 (DPP4) as its receptor. The distribution of DPP4 in the respiratory tract tissues of humans and camels reflects MERS-CoV tropism. Apart from dromedary

  15. Livestock Susceptibility to Infection with Middle East Respiratory Syndrome Coronavirus

    NARCIS (Netherlands)

    Vergara-Alert, Júlia; van den Brand, Judith M A; Widagdo, W; Muñoz, Marta; Raj, V Stalin; Schipper, Debby; Solanes, David; Cordón, Ivan; Bensaid, Albert; Haagmans, Bart L; Segalés, Joaquim

    Middle East respiratory syndrome (MERS) cases continue to be reported, predominantly in Saudi Arabia and occasionally other countries. Although dromedaries are the main reservoir, other animal species might be susceptible to MERS coronavirus (MERS-CoV) infection and potentially serve as reservoirs.

  16. Transmission of MERS-coronavirus in household contacts

    NARCIS (Netherlands)

    Drosten, Christian; Meyer, Benjamin; Müller, Marcel A; Corman, Victor M; Al-Masri, Malak; Hossain, Raheela; Madani, Hosam; Sieberg, Andrea; Bosch, Berend Jan|info:eu-repo/dai/nl/273306049; Lattwein, Erik; Alhakeem, Raafat F; Assiri, Abdullah M; Hajomar, Waleed; Albarrak, Ali M; Al-Tawfiq, Jaffar A; Zumla, Alimuddin I; Memish, Ziad A

    2014-01-01

    BACKGROUND: Strategies to contain the Middle East respiratory syndrome coronavirus (MERS-CoV) depend on knowledge of the rate of human-to-human transmission, including subclinical infections. A lack of serologic tools has hindered targeted studies of transmission. METHODS: We studied 26 index

  17. Cytoplasmic tail of coronavirus spike protein has intracellular

    Indian Academy of Sciences (India)

    https://www.ias.ac.in/article/fulltext/jbsc/042/02/0231-0244. Keywords. Coronavirus spike protein trafficking; cytoplasmic tail signal; endoplasmic reticulum–Golgi intermediate complex; lysosome. Abstract. Intracellular trafficking and localization studies of spike protein from SARS and OC43 showed that SARS spikeprotein is ...

  18. Renin-angiotensin system in human coronavirus pathogenesis

    NARCIS (Netherlands)

    Wevers, Brigitte A.; van der Hoek, Lia

    2010-01-01

    Although initially considered relatively harmless pathogens, human coronaviruses (HCoVs) are nowadays known to be associated with more severe clinical complications. Still, their precise pathogenic potential is largely unknown, particularly regarding the most recently identified species HCoV-NL63

  19. Coronavirus nucleocapsid proteins assemble constitutively in high molecular oligomers

    NARCIS (Netherlands)

    Cong, Yingying; Kriegenburg, Franziska; de Haan, Cornelis A. M.; Reggiori, Fulvio

    2017-01-01

    Coronaviruses (CoV) are enveloped viruses and rely on their nucleocapsid N protein to incorporate the positive-stranded genomic RNA into the virions. CoV N proteins form oligomers but the mechanism and relevance underlying their multimerization remain to be fully understood. Using in vitro pull-down

  20. Multifunctional Mitochondrial AAA Proteases.

    Science.gov (United States)

    Glynn, Steven E

    2017-01-01

    Mitochondria perform numerous functions necessary for the survival of eukaryotic cells. These activities are coordinated by a diverse complement of proteins encoded in both the nuclear and mitochondrial genomes that must be properly organized and maintained. Misregulation of mitochondrial proteostasis impairs organellar function and can result in the development of severe human diseases. ATP-driven AAA+ proteins play crucial roles in preserving mitochondrial activity by removing and remodeling protein molecules in accordance with the needs of the cell. Two mitochondrial AAA proteases, i-AAA and m-AAA, are anchored to either face of the mitochondrial inner membrane, where they engage and process an array of substrates to impact protein biogenesis, quality control, and the regulation of key metabolic pathways. The functionality of these proteases is extended through multiple substrate-dependent modes of action, including complete degradation, partial processing, or dislocation from the membrane without proteolysis. This review discusses recent advances made toward elucidating the mechanisms of substrate recognition, handling, and degradation that allow these versatile proteases to control diverse activities in this multifunctional organelle.

  1. The SARS-coronavirus-host interactome: identification of cyclophilins as target for pan-coronavirus inhibitors.

    Directory of Open Access Journals (Sweden)

    Susanne Pfefferle

    2011-10-01

    Full Text Available Coronaviruses (CoVs are important human and animal pathogens that induce fatal respiratory, gastrointestinal and neurological disease. The outbreak of the severe acute respiratory syndrome (SARS in 2002/2003 has demonstrated human vulnerability to (Coronavirus CoV epidemics. Neither vaccines nor therapeutics are available against human and animal CoVs. Knowledge of host cell proteins that take part in pivotal virus-host interactions could define broad-spectrum antiviral targets. In this study, we used a systems biology approach employing a genome-wide yeast-two hybrid interaction screen to identify immunopilins (PPIA, PPIB, PPIH, PPIG, FKBP1A, FKBP1B as interaction partners of the CoV non-structural protein 1 (Nsp1. These molecules modulate the Calcineurin/NFAT pathway that plays an important role in immune cell activation. Overexpression of NSP1 and infection with live SARS-CoV strongly increased signalling through the Calcineurin/NFAT pathway and enhanced the induction of interleukin 2, compatible with late-stage immunopathogenicity and long-term cytokine dysregulation as observed in severe SARS cases. Conversely, inhibition of cyclophilins by cyclosporine A (CspA blocked the replication of CoVs of all genera, including SARS-CoV, human CoV-229E and -NL-63, feline CoV, as well as avian infectious bronchitis virus. Non-immunosuppressive derivatives of CspA might serve as broad-range CoV inhibitors applicable against emerging CoVs as well as ubiquitous pathogens of humans and livestock.

  2. Host cell entry of Middle East respiratory syndrome coronavirus after two-step, furin-mediated activation of the spike protein

    Science.gov (United States)

    Millet, Jean Kaoru; Whittaker, Gary R.

    2014-01-01

    Middle East respiratory syndrome coronavirus (MERS-CoV) is a newly identified betacoronavirus causing high morbidity and mortality in humans. The coronavirus spike (S) protein is the main determinant of viral entry, and although it was previously shown that MERS-CoV S can be activated by various proteases, the details of the mechanisms of proteolytic activation of fusion are still incompletely characterized. Here, we have uncovered distinctive characteristics of MERS-CoV S. We identify, by bioinformatics and peptide cleavage assays, two cleavage sites for furin, a ubiquitously expressed protease, which are located at the S1/S2 interface and at the S2′ position of the S protein. We show that although the S1/S2 site is proteolytically processed by furin during protein biosynthesis, the S2′ site is cleaved upon viral entry. MERS-CoV pseudovirion infection was shown to be enhanced by elevated levels of furin expression, and entry could be decreased by furin siRNA silencing. Enhanced furin activity appeared to partially override the low pH-dependent nature of MERS-CoV entry. Inhibition of furin activity was shown to decrease MERS-CoV S-mediated entry, as well as infection by the virus. Overall, we show that MERS-CoV has evolved an unusual two-step furin activation for fusion, suggestive of a role during the process of emergence into the human population. The ability of MERS-CoV to use furin in this manner, along with other proteases, may explain the polytropic nature of the virus. PMID:25288733

  3. Coronavirus infection in mink (Mustela vison). Serological evidence of infection with a coronavirus related to transmissible gastroenteritis virus and porcine epidemic diarrhea virus

    DEFF Research Database (Denmark)

    Have, P; Moving, V; Svansson, V

    1992-01-01

    Antibodies to a transmissible gastroenteritis virus (TGEV)-related coronavirus have been demonstrated in mink sera by indirect immunofluorescence, peroxidase-linked antibody assays and immunoblotting. This is the first serological evidence of a specific coronavirus infection in mink. The putative...

  4. Coronavirus-like particles in laboratory rabbits with different syndromes in The Netherlands (Coronavirus-like particles in rabbits).

    NARCIS (Netherlands)

    A.D.M.E. Osterhaus (Albert); J.S. Teppema; G. van Steenis (Bert)

    1982-01-01

    textabstractVirus-like particles were identified from the plasma of rabbits which developed pleural effusion disease after inoculation with different strains of Treponema pallidum. These particles were considered coronavirus-like on the basis of their size, morphology, and buoyant density. Clinical

  5. Crystal Structure of Feline Infectious Peritonitis Virus Main Protease in Complex with Synergetic Dual Inhibitors.

    Science.gov (United States)

    Wang, Fenghua; Chen, Cheng; Liu, Xuemeng; Yang, Kailin; Xu, Xiaoling; Yang, Haitao

    2016-02-15

    Coronaviruses (CoVs) can cause highly prevalent diseases in humans and animals. Feline infectious peritonitis virus (FIPV) belongs to the genus Alphacoronavirus, resulting in a lethal systemic granulomatous disease called feline infectious peritonitis (FIP), which is one of the most important fatal infectious diseases of cats worldwide. No specific vaccines or drugs have been approved to treat FIP. CoV main proteases (M(pro)s) play a pivotal role in viral transcription and replication, making them an ideal target for drug development. Here, we report the crystal structure of FIPV M(pro) in complex with dual inhibitors, a zinc ion and a Michael acceptor. The complex structure elaborates a unique mechanism of two distinct inhibitors synergizing to inactivate the protease, providing a structural basis to design novel antivirals and suggesting the potential to take advantage of zinc as an adjunct therapy against CoV-associated diseases. Coronaviruses (CoVs) have the largest genome size among all RNA viruses. CoV infection causes various diseases in humans and animals, including severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS). No approved specific drugs or vaccinations are available to treat their infections. Here, we report a novel dual inhibition mechanism targeting CoV main protease (M(pro)) from feline infectious peritonitis virus (FIPV), which leads to lethal systemic granulomatous disease in cats. M(pro), conserved across all CoV genomes, is essential for viral replication and transcription. We demonstrated that zinc ion and a Michael acceptor-based peptidomimetic inhibitor synergistically inactivate FIPV M(pro). We also solved the structure of FIPV M(pro) complexed with two inhibitors, delineating the structural view of a dual inhibition mechanism. Our study provides new insight into the pharmaceutical strategy against CoV M(pro) through using zinc as an adjuvant therapy to enhance the efficacy of an irreversible

  6. Crystal structure of mouse coronavirus receptor-binding domain complexed with its murine receptor

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Guiqing; Sun, Dawei; Rajashankar, Kanagalaghatta R.; Qian, Zhaohui; Holmes, Kathryn V.; Li, Fang (Cornell); (UMM-MED); (Colorado)

    2011-09-28

    Coronaviruses have evolved diverse mechanisms to recognize different receptors for their cross-species transmission and host-range expansion. Mouse hepatitis coronavirus (MHV) uses the N-terminal domain (NTD) of its spike protein as its receptor-binding domain. Here we present the crystal structure of MHV NTD complexed with its receptor murine carcinoembryonic antigen-related cell adhesion molecule 1a (mCEACAM1a). Unexpectedly, MHV NTD contains a core structure that has the same {beta}-sandwich fold as human galectins (S-lectins) and additional structural motifs that bind to the N-terminal Ig-like domain of mCEACAM1a. Despite its galectin fold, MHV NTD does not bind sugars, but instead binds mCEACAM1a through exclusive protein-protein interactions. Critical contacts at the interface have been confirmed by mutagenesis, providing a structural basis for viral and host specificities of coronavirus/CEACAM1 interactions. Sugar-binding assays reveal that galectin-like NTDs of some coronaviruses such as human coronavirus OC43 and bovine coronavirus bind sugars. Structural analysis and mutagenesis localize the sugar-binding site in coronavirus NTDs to be above the {beta}-sandwich core. We propose that coronavirus NTDs originated from a host galectin and retained sugar-binding functions in some contemporary coronaviruses, but evolved new structural features in MHV for mCEACAM1a binding.

  7. A rare cause of acute flaccid paralysis: Human coronaviruses

    OpenAIRE

    Turgay, Cokyaman; Emine, Tekin; Ozlem, Koken; Muhammet, S. Paksu; Haydar, A. Tasdemir

    2015-01-01

    Acute flaccid paralysis (AFP) is a life-threatening clinical entity characterized by weakness in the whole body muscles often accompanied by respiratory and bulbar paralysis. The most common cause is Gullian-Barre syndrome, but infections, spinal cord diseases, neuromuscular diseases such as myasthenia gravis, drugs and toxins, periodic hypokalemic paralysis, electrolyte disturbances, and botulism should be considered as in the differential diagnosis. Human coronaviruses (HCoVs) cause common ...

  8. Detection of Coronaviruses in Bats of Various Species in Italy

    Directory of Open Access Journals (Sweden)

    Maria B. Boniotti

    2013-10-01

    Full Text Available Bats are natural reservoirs for many mammalian coronaviruses, which have received renewed interest after the discovery of the severe acute respiratory syndrome (SARS and the Middle East respiratory syndrome (MERS CoV in humans. This study describes the identification and molecular characterization of alphacoronaviruses and betacoronaviruses in bats in Italy, from 2010 to 2012. Sixty-nine faecal samples and 126 carcasses were tested using pan-coronavirus RT-PCR. Coronavirus RNAs were detected in seven faecal samples and nine carcasses. A phylogenetic analysis of RNA-dependent RNA polymerase sequence fragments aided in identifying two alphacoronaviruses from Kuhl’s pipistrelle (Pipistrellus kuhlii, three clade 2b betacoronaviruses from lesser horseshoe bats (Rhinolophus hipposideros, and 10 clade 2c betacoronaviruses from Kuhl’s pipistrelle, common noctule (Nyctalus noctula, and Savi’s pipistrelle (Hypsugo savii. This study fills a substantive gap in the knowledge on bat-CoV ecology in Italy, and extends the current knowledge on clade 2c betacoronaviruses with new sequences obtained from bats that have not been previously described as hosts of these viruses.

  9. Prevalence of Korean cats with natural feline coronavirus infections

    Directory of Open Access Journals (Sweden)

    Lee Myoung-Heon

    2011-09-01

    Full Text Available Abstract Background Feline coronavirus is comprised of two pathogenic biotypes consisting of feline infectious peritonitis virus (FIPV and feline enteric coronavirus (FECV, which are both divided into two serotypes. To examine the prevalence of Korean cats infected with feline coronavirus (FCoV type I and II, fecal samples were obtained from 212 cats (107 pet and 105 feral in 2009. Results Fourteen cats were FCoV-positive, including infections with type I FCoV (n = 8, type II FCoV (n = 4, and types I and II co-infection (n = 2. Low seroprevalences (13.7%, 29/212 of FCoV were identified in chronically ill cats (19.3%, 16/83 and healthy cats (10.1%, 13/129. Conclusions Although the prevalence of FCoV infection was not high in comparison to other countries, there was a higher prevalence of type I FCoV in Korean felines. The prevalence of FCoV antigen and antibody in Korean cats are expected to gradually increase due to the rising numbers of stray and companion cats.

  10. Mosaic Evolution of the Severe Acute Respiratory Syndrome Coronavirus

    Science.gov (United States)

    Stavrinides, John; Guttman, David S.

    2004-01-01

    Severe acute respiratory syndrome (SARS) is a deadly form of pneumonia caused by a novel coronavirus, a viral family responsible for mild respiratory tract infections in a wide variety of animals including humans, pigs, cows, mice, cats, and birds. Analyses to date have been unable to identify the precise origin of the SARS coronavirus. We used Bayesian, neighbor-joining, and split decomposition phylogenetic techniques on the SARS virus replicase, surface spike, matrix, and nucleocapsid proteins to reveal the evolutionary origin of this recently emerging infectious agent. The analyses support a mammalian-like origin for the replicase protein, an avian-like origin for the matrix and nucleocapsid proteins, and a mammalian-avian mosaic origin for the host-determining spike protein. A bootscan recombination analysis of the spike gene revealed high nucleotide identity between the SARS virus and a feline infectious peritonitis virus throughout the gene, except for a 200- base-pair region of high identity to an avian sequence. These data support the phylogenetic analyses and suggest a possible past recombination event between mammalian-like and avian-like parent viruses. This event occurred near a region that has been implicated to be the human receptor binding site and may have been directly responsible for the switch of host of the SARS coronavirus from animals to humans. PMID:14671089

  11. Insecticide resistance and intracellular proteases.

    Science.gov (United States)

    Wilkins, Richard M

    2017-12-01

    Pesticide resistance is an example of evolution in action with mechanisms of resistance arising from mutations or increased expression of intrinsic genes. Intracellular proteases have a key role in maintaining healthy cells and in responding to stressors such as pesticides. Insecticide-resistant insects have constitutively elevated intracellular protease activity compared to corresponding susceptible strains. This increase was shown for some cases originally through biochemical enzyme studies and subsequently putatively by transcriptomics and proteomics methods. Upregulation and expression of proteases have been characterised in resistant strains of some insect species, including mosquitoes. This increase in proteolysis results in more degradation products (amino acids) of intracellular proteins. These may be utilised in the resistant strain to better protect the cell from stress. There are changes in insect intracellular proteases shortly after insecticide exposure, suggesting a role in stress response. The use of protease and proteasome inhibitors or peptide mimetics as synergists with improved application techniques and through protease gene knockdown using RNA interference (possibly expressed in crop plants) may be potential pest management strategies, in situations where elevated intracellular proteases are relevant. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  12. Evidence for an ancestral association of human coronavirus 229E with bats

    Czech Academy of Sciences Publication Activity Database

    Corman, V. M.; Baldwin, H. J.; Tateno, A. F.; Zerbinati, R. M.; Annan, A.; Owusu, M.; Nkrumah, E. E.; Maganga, G. D.; Oppong, S.; Adu-Sarkodie, Y.; Vallo, Peter; da Silva Filho, L. V. R. F.; Leroy, E. M.; Thiel, V.; van der Hoek, L.; Poon, L. L. M.; Tschapka, M.; Drosten, C.; Drexler, J. F.

    2015-01-01

    Roč. 89, č. 23 (2015), s. 11858-11870 ISSN 0022-538X Institutional support: RVO:68081766 Keywords : respiratory syndrome coronavirus * SARS-coronavirus * genomic characterization * dromedary camels * clinical impact * virus * children * protein * spike * classification Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 4.606, year: 2015

  13. The coronavirus spike protein : mechanisms of membrane fusion and virion incorporation

    NARCIS (Netherlands)

    Bosch, B.J.

    2004-01-01

    The coronavirus spike protein is a membrane-anchored glycoprotein responsible for virus-cell attachment and membrane fusion, prerequisites for a successful virus infection. In this thesis, two aspects are described regarding the molecular biology of the coronavirus spike protein: its membrane fusion

  14. On the biased nucleotide composition of the human coronavirus RNA genome

    NARCIS (Netherlands)

    Berkhout, Ben; van Hemert, Formijn

    2015-01-01

    We investigated the nucleotide composition of the RNA genome of the six human coronaviruses. Some general coronavirus characteristics were apparent (e.g. high U, low C count), but we also detected species-specific signatures. Most strikingly, the high U and low C proportions are quite variable and

  15. Molecular epidemiology of bovine coronavirus on the basis of comparative analyses of the S gene

    DEFF Research Database (Denmark)

    Liu, Lihong; Hägglund, Sara; Hakhverdyan, Mikhayil

    2006-01-01

    Bovine coronavirus (BCoV), a group 2 member of the genus Coronavirus in the family Coronaviridae, is an important pathogen in cattle worldwide. It causes diarrhea in adult animals (winter dysentery), as well as enteric and respiratory diseases in calves. The annual occurrence of BCoV epidemics...

  16. Human Coronaviruses 229E and NL63: Close Yet Still So Far

    NARCIS (Netherlands)

    Dijkman, Ronald; van der Hoek, Lia

    2009-01-01

    HCoV-NL63 and HCoV-229E are two of the four human coronaviruses that circulate worldwide. These two viruses are unique in their relationship towards each other. Phylogenetically, the viruses are more closely related to each other than to any other human coronavirus, yet they only share 65% sequence

  17. Isolation and characterization of a novel Betacoronavirus subgroup A coronavirus, rabbit coronavirus HKU14, from domestic rabbits.

    Science.gov (United States)

    Lau, Susanna K P; Woo, Patrick C Y; Yip, Cyril C Y; Fan, Rachel Y Y; Huang, Yi; Wang, Ming; Guo, Rongtong; Lam, Carol S F; Tsang, Alan K L; Lai, Kenneth K Y; Chan, Kwok-Hung; Che, Xiao-Yan; Zheng, Bo-Jian; Yuen, Kwok-Yung

    2012-05-01

    We describe the isolation and characterization of a novel Betacoronavirus subgroup A coronavirus, rabbit coronavirus HKU14 (RbCoV HKU14), from domestic rabbits. The virus was detected in 11 (8.1%) of 136 rabbit fecal samples by reverse transcriptase PCR (RT-PCR), with a viral load of up to 10(8) copies/ml. RbCoV HKU14 was able to replicate in HRT-18G and RK13 cells with cytopathic effects. Northern blotting confirmed the production of subgenomic mRNAs coding for the HE, S, NS5a, E, M, and N proteins. Subgenomic mRNA analysis revealed a transcription regulatory sequence, 5'-UCUAAAC-3'. Phylogenetic analysis showed that RbCoV HKU14 formed a distinct branch among Betacoronavirus subgroup A coronaviruses, being most closely related to but separate from the species Betacoronavirus 1. A comparison of the conserved replicase domains showed that RbCoV HKU14 possessed N-protein-based Western blot assay, whereas neutralizing antibody was detected in 1 of these 20 rabbits.

  18. A noncovalent class of papain-like protease/deubiquitinase inhibitors blocks SARS virus replication

    Energy Technology Data Exchange (ETDEWEB)

    Ratia, Kiira; Pegan, Scott; Takayama, Jun; Sleeman, Katrina; Coughlin, Melissa; Baliji, Surendranath; Chaudhuri, Rima; Fu, Wentao; Prabhakar, Bellur S.; Johnson, Michael E.; Baker, Susan C.; Ghosh, Arun K.; Mesecar, Andrew D. (Loyola); (Purdue); (UIC)

    2008-10-27

    We report the discovery and optimization of a potent inhibitor against the papain-like protease (PLpro) from the coronavirus that causes severe acute respiratory syndrome (SARS-CoV). This unique protease is not only responsible for processing the viral polyprotein into its functional units but is also capable of cleaving ubiquitin and ISG15 conjugates and plays a significant role in helping SARS-CoV evade the human immune system. We screened a structurally diverse library of 50,080 compounds for inhibitors of PLpro and discovered a noncovalent lead inhibitor with an IC{sub 50} value of 20 {mu}M, which was improved to 600 nM via synthetic optimization. The resulting compound, GRL0617, inhibited SARS-CoV viral replication in Vero E6 cells with an EC{sub 50} of 15 {mu}M and had no associated cytotoxicity. The X-ray structure of PLpro in complex with GRL0617 indicates that the compound has a unique mode of inhibition whereby it binds within the S4-S3 subsites of the enzyme and induces a loop closure that shuts down catalysis at the active site. These findings provide proof-of-principle that PLpro is a viable target for development of antivirals directed against SARS-CoV, and that potent noncovalent cysteine protease inhibitors can be developed with specificity directed toward pathogenic deubiquitinating enzymes without inhibiting host DUBs.

  19. Co-evolution of insect proteases and plant protease inhibitors.

    Science.gov (United States)

    Jongsma, Maarten A; Beekwilder, Jules

    2011-08-01

    Plants are at the basis of the food chain, but there is no such thing as a "free lunch" for herbivores. To promote reproductive success, plants evolved multi-layered defensive tactics to avoid or discourage herbivory. To the detriment of plants, herbivores, in turn, evolved intricate strategies to find, eat, and successfully digest essential plant parts to raise their own offspring. In this battle the digestive tract is the arena determining final victory or defeat as measured by growth or starvation of the herbivore. Earlier, specific molecular opponents were identified as proteases and inhibitors: digestive proteases of herbivores evolved structural motifs to occlude plant protease inhibitors, or alternatively, the insects evolved proteases capable of specifically degrading the host plant inhibitors. In response plant inhibitors evolved hyper-variable and novel protein folds to remain active against potential herbivores. At the level of protease regulation in herbivorous insects, it was shown that inhibition-insensitive digestive proteases are up-regulated when sensitive proteases are inhibited. The way this regulation operates in mammals is known as negative feedback by gut-luminal factors, so-called 'monitor peptides' that are sensitive to the concentration of active enzymes. We propose that regulation of gut enzymes by endogenous luminal factors has been an open invitation to plants to "hijack" this regulation by evolving receptor antagonists, although yet these plant factors have not been identified. In future research the question of the co-evolution of insect proteases and plant inhibitors should, therefore, be better approached from a systems level keeping in mind that evolution is fundamentally opportunistic and that the plant's fitness is primarily improved by lowering the availability of essential amino acids to an herbivore by any available mechanism.

  20. Identification of Alpha and Beta Coronavirus in Wildlife Species in France: Bats, Rodents, Rabbits, and Hedgehogs

    Directory of Open Access Journals (Sweden)

    Elodie Monchatre-Leroy

    2017-11-01

    Full Text Available Coronaviruses are closely monitored in the context of emerging diseases and, as illustrated with Severe Acute Respiratory Syndrome coronavirus (SARS-CoV and Middle East Respiratory Syndrome-coronavirus (MERS-CoV, are known to cross the species barrier and eventually to move from wildlife to humans. Knowledge of the diversity of coronaviruses in wildlife is therefore essential to better understand and prevent emergence events. This study explored the presence of coronaviruses in four wild mammal orders in France: Bats, rodents, lagomorphs, and hedgehogs. Betacoronavirus and Alphacoronavirus genera were identified. The results obtained suggest the circulation of potentially evolving virus strains, with the potential to cross the species barrier.

  1. Detection of a group 2 coronavirus in dogs with canine infectious respiratory disease

    International Nuclear Information System (INIS)

    Erles, Kerstin; Toomey, Crista; Brooks, Harriet W.; Brownlie, Joe

    2003-01-01

    An investigation into the causes of canine infectious respiratory disease was carried out in a large rehoming kennel. Tissue samples taken from the respiratory tract of diseased dogs were tested for the presence of coronaviruses using RT-PCR with conserved primers for the polymerase gene. Sequence analysis of four positive samples showed the presence of a coronavirus with high similarity to both bovine and human coronavirus (strain OC43) in their polymerase and spike genes, whereas there was a low similarity to comparable genes in the enteric canine coronavirus. This canine respiratory coronavirus (CRCV) was detected by RT-PCR in 32/119 tracheal and 20/119 lung samples, with the highest prevalence being detected in dogs with mild clinical symptoms. Serological analysis showed that the presence of antibodies against CRCV on the day of entry into the kennel decreased the risk of developing respiratory disease

  2. Mechanisms of Coronavirus Cell Entry Mediated by the Viral Spike Protein

    Directory of Open Access Journals (Sweden)

    Gary R. Whittaker

    2012-06-01

    Full Text Available Coronaviruses are enveloped positive-stranded RNA viruses that replicate in the cytoplasm. To deliver their nucleocapsid into the host cell, they rely on the fusion of their envelope with the host cell membrane. The spike glycoprotein (S mediates virus entry and is a primary determinant of cell tropism and pathogenesis. It is classified as a class I fusion protein, and is responsible for binding to the receptor on the host cell as well as mediating the fusion of host and viral membranes—A process driven by major conformational changes of the S protein. This review discusses coronavirus entry mechanisms focusing on the different triggers used by coronaviruses to initiate the conformational change of the S protein: receptor binding, low pH exposure and proteolytic activation. We also highlight commonalities between coronavirus S proteins and other class I viral fusion proteins, as well as distinctive features that confer distinct tropism, pathogenicity and host interspecies transmission characteristics to coronaviruses.

  3. Coronavirus minus-strand RNA synthesis and effect of cycloheximide on coronavirus RNA synthesis

    International Nuclear Information System (INIS)

    Sawicki, S.G.; Sawicki, D.L.

    1986-01-01

    The temporal sequence of coronavirus plus-strand and minus-strand RNA synthesis was determined in 17CL1 cells infected with the A59 strain of mouse hepatitis virus (MHV). MHV-induced fusion was prevented by keeping the pH of the medium below pH 6.8. This had no effect on the MHV replication cycle, but gave 5- to 10-fold-greater titers of infectious virus and delayed the detachment of cells from the monolayer which permitted viral RNA synthesis to be studied conveniently until at least 10 h postinfection. Seven species of poly(A)-containing viral RNAs were synthesized at early and late times infection, in nonequal but constant ratios. MHV minus-strand RNA synthesis was first detected at about 3 h after infection and was found exclusively in the viral replicative intermediates and was not detected in 60S single-stranded form in infected cells. Early in the replication cycle, from 45 to 65% of the [ 3 H]uridine pulse-labeled RF core of purified MHV replicative intermediates was in minus-strand RNA. The rate of minus-strand synthesis peaked at 5 to 6 h postinfection and then declined to about 20% of the maximum rate. The addition of cycloheximide before 3 h postinfection prevented viral RNA synthesis, whereas the addition of cycloheximide after viral RNA synthesis had begun resulted in the inhibition of viral RNA synthesis. The synthesis of both genome and subgenomic mRNAs and of viral minus strands required continued protein synthesis, and minis-strand RNA synthesis was three- to fourfold more sensitive to inhibition of cycloheximide than was plus-strand synthesis

  4. p53 down-regulates SARS coronavirus replication and is targeted by the SARS-unique domain and PLpro via E3 ubiquitin ligase RCHY1

    Science.gov (United States)

    Ma-Lauer, Yue; Carbajo-Lozoya, Javier; Müller, Marcel A.; Deng, Wen; Lei, Jian; Meyer, Benjamin; Kusov, Yuri; von Brunn, Brigitte; Bairad, Dev Raj; Hünten, Sabine; Drosten, Christian; Hermeking, Heiko; Leonhardt, Heinrich; Mann, Matthias; Hilgenfeld, Rolf; von Brunn, Albrecht

    2016-01-01

    Highly pathogenic severe acute respiratory syndrome coronavirus (SARS-CoV) has developed strategies to inhibit host immune recognition. We identify cellular E3 ubiquitin ligase ring-finger and CHY zinc-finger domain-containing 1 (RCHY1) as an interacting partner of the viral SARS-unique domain (SUD) and papain-like protease (PLpro), and, as a consequence, the involvement of cellular p53 as antagonist of coronaviral replication. Residues 95–144 of RCHY1 and 389–652 of SUD (SUD-NM) subdomains are crucial for interaction. Association with SUD increases the stability of RCHY1 and augments RCHY1-mediated ubiquitination as well as degradation of p53. The calcium/calmodulin-dependent protein kinase II delta (CAMK2D), which normally influences RCHY1 stability by phosphorylation, also binds to SUD. In vivo phosphorylation shows that SUD does not regulate phosphorylation of RCHY1 via CAMK2D. Similarly to SUD, the PLpros from SARS-CoV, MERS-CoV, and HCoV-NL63 physically interact with and stabilize RCHY1, and thus trigger degradation of endogenous p53. The SARS-CoV papain-like protease is encoded next to SUD within nonstructural protein 3. A SUD–PLpro fusion interacts with RCHY1 more intensively and causes stronger p53 degradation than SARS-CoV PLpro alone. We show that p53 inhibits replication of infectious SARS-CoV as well as of replicons and human coronavirus NL63. Hence, human coronaviruses antagonize the viral inhibitor p53 via stabilizing RCHY1 and promoting RCHY1-mediated p53 degradation. SUD functions as an enhancer to strengthen interaction between RCHY1 and nonstructural protein 3, leading to a further increase in in p53 degradation. The significance of these findings is that down-regulation of p53 as a major player in antiviral innate immunity provides a long-sought explanation for delayed activities of respective genes. PMID:27519799

  5. The Paradox of Feline Coronavirus Pathogenesis: A Review

    Directory of Open Access Journals (Sweden)

    Luciana Wanderley Myrrha

    2011-01-01

    Full Text Available Feline coronavirus (FCoV is an enveloped single-stranded RNA virus, of the family Coronaviridae and the order Nidovirales. FCoV is an important pathogen of wild and domestic cats and can cause a mild or apparently symptomless enteric infection, especially in kittens. FCoV is also associated with a lethal, systemic disease known as feline infectious peritonitis (FIP. Although the precise cause of FIP pathogenesis remains unclear, some hypotheses have been suggested. In this review we present results from different FCoV studies and attempt to elucidate existing theories on the pathogenesis of FCoV infection.

  6. Crystal structure of Middle East respiratory syndrome coronavirus helicase.

    Directory of Open Access Journals (Sweden)

    Wei Hao

    2017-06-01

    Full Text Available Middle East respiratory syndrome coronavirus (MERS-CoV remains a threat to public health worldwide; however, effective vaccine or drug against CoVs remains unavailable. CoV helicase is one of the three evolutionary most conserved proteins in nidoviruses, thus making it an important target for drug development. We report here the first structure of full-length coronavirus helicase, MERS-CoV nsp13. MERS-CoV helicase has multiple domains, including an N-terminal Cys/His rich domain (CH with three zinc atoms, a beta-barrel domain and a C-terminal SF1 helicase core with two RecA-like subdomains. Our structural analyses show that while the domain organization of nsp13 is conserved throughout nidoviruses, the individual domains of nsp13 are closely related to the equivalent eukaryotic domains of Upf1 helicases. The most distinctive feature differentiating CoV helicases from eukaryotic Upf1 helicases is the interaction between CH domain and helicase core.

  7. Coronavirus envelope (E) protein remains at the site of assembly

    International Nuclear Information System (INIS)

    Venkatagopalan, Pavithra; Daskalova, Sasha M.; Lopez, Lisa A.; Dolezal, Kelly A.; Hogue, Brenda G.

    2015-01-01

    Coronaviruses (CoVs) assemble at endoplasmic reticulum Golgi intermediate compartment (ERGIC) membranes and egress from cells in cargo vesicles. Only a few molecules of the envelope (E) protein are assembled into virions. The role of E in morphogenesis is not fully understood. The cellular localization and dynamics of mouse hepatitis CoV A59 (MHV) E protein were investigated to further understanding of its role during infection. E protein localized in the ERGIC and Golgi with the amino and carboxy termini in the lumen and cytoplasm, respectively. E protein does not traffic to the cell surface. MHV was genetically engineered with a tetracysteine tag at the carboxy end of E. Fluorescence recovery after photobleaching (FRAP) showed that E is mobile in ERGIC/Golgi membranes. Correlative light electron microscopy (CLEM) confirmed the presence of E in Golgi cisternae. The results provide strong support that E proteins carry out their function(s) at the site of budding/assembly. - Highlights: • Mouse hepatitis coronavirus (MHV-CoV) E protein localizes in the ERGIC and Golgi. • MHV-CoV E does not transport to the cell surface. • MHV-CoV can be genetically engineered with a tetracysteine tag appended to E. • First FRAP and correlative light electron microscopy of a CoV E protein. • Live-cell imaging shows that E is mobile in ERGIC/Golgi membranes

  8. Vacuolating encephalitis in mice infected by human coronavirus OC43

    International Nuclear Information System (INIS)

    Jacomy, Helene; Talbot, Pierre J.

    2003-01-01

    Involvement of viruses in human neurodegenerative diseases and the underlying pathologic mechanisms remain generally unclear. Human respiratory coronaviruses (HCoV) can infect neural cells, persist in human brain, and activate myelin-reactive T cells. As a means of understanding the human infection, we characterized in vivo the neurotropic and neuroinvasive properties of HCoV-OC43 through the development of an experimental animal model. Virus inoculation of 21-day postnatal C57BL/6 and BALB/c mice led to a generalized infection of the whole CNS, demonstrating HCoV-OC43 neuroinvasiveness and neurovirulence. This acute infection targeted neurons, which underwent vacuolation and degeneration while infected regions presented strong microglial reactivity and inflammatory reactions. Damage to the CNS was not immunologically mediated and microglial reactivity was instead a consequence of direct virus-mediated neuronal injury. Although this acute encephalitis appears generally similar to that induced by murine coronaviruses, an important difference rests in the prominent spongiform-like degeneration that could trigger neuropathology in surviving animals

  9. Pathogenic characteristics of persistent feline enteric coronavirus infection in cats

    Science.gov (United States)

    Vogel, Liesbeth; Van der Lubben, Mariken; Te Lintelo, Eddie G.; Bekker, Cornelis P.J.; Geerts, Tamara; Schuijff, Leontine S.; Grinwis, Guy C.M.; Egberink, Herman F.; Rottier, Peter J.M.

    2010-01-01

    Feline coronaviruses (FCoV) comprise two biotypes: feline enteric coronaviruses (FECV) and feline infectious peritonitis viruses (FIPV). FECV is associated with asymptomatic persistent enteric infections, while FIPV causes feline infectious peritonitis (FIP), a usually fatal systemic disease in domestic cats and some wild Felidae. FIPV arises from FECV by mutation. FCoV also occur in two serotypes, I and II, of which the serotype I viruses are by far the most prevalent in the field. Yet, most of our knowledge about FCoV infections relates to serotype II viruses, particularly about the FIPV, mainly because type I viruses grow poorly in cell culture. Hence, the aim of the present work was the detailed study of the epidemiologically most relevant viruses, the avirulent serotype I viruses. Kittens were inoculated oronasally with different doses of two independent FECV field strains, UCD and RM. Persistent infection could be reproducibly established. The patterns of clinical symptoms, faecal virus shedding and seroconversion were monitored for up to 10 weeks revealing subtle but reproducible differences between the two viruses. Faecal virus, i.e. genomic RNA, was detected during persistent FECV infection only in the large intestine, downstream of the appendix, and could occasionally be observed also in the blood. The implications of our results, particularly our insights into the persistently infected state, are discussed. PMID:20663472

  10. Coronavirus envelope (E) protein remains at the site of assembly

    Energy Technology Data Exchange (ETDEWEB)

    Venkatagopalan, Pavithra [The Biodesign Institute, Center for Infectious Diseases and Vaccinology, Arizona State University, Tempe, AZ 85287-5401 (United States); School of Life Sciences, Arizona State University, Tempe, AZ 85287-5401 (United States); Microbiology Graduate Program, Arizona State University, Tempe, AZ 85287-5401 (United States); Daskalova, Sasha M. [The Biodesign Institute, Center for Infectious Diseases and Vaccinology, Arizona State University, Tempe, AZ 85287-5401 (United States); Department of Biochemistry and Chemistry, Arizona State University, Tempe, AZ 85287-5401 (United States); Lopez, Lisa A. [The Biodesign Institute, Center for Infectious Diseases and Vaccinology, Arizona State University, Tempe, AZ 85287-5401 (United States); School of Life Sciences, Arizona State University, Tempe, AZ 85287-5401 (United States); Molecular and Cellular Biology Graduate Program, Arizona State University, Tempe, AZ 85287-5401 (United States); Dolezal, Kelly A. [The Biodesign Institute, Center for Infectious Diseases and Vaccinology, Arizona State University, Tempe, AZ 85287-5401 (United States); School of Life Sciences, Arizona State University, Tempe, AZ 85287-5401 (United States); Microbiology Graduate Program, Arizona State University, Tempe, AZ 85287-5401 (United States); Hogue, Brenda G., E-mail: Brenda.Hogue@asu.edu [The Biodesign Institute, Center for Infectious Diseases and Vaccinology, Arizona State University, Tempe, AZ 85287-5401 (United States); School of Life Sciences, Arizona State University, Tempe, AZ 85287-5401 (United States)

    2015-04-15

    Coronaviruses (CoVs) assemble at endoplasmic reticulum Golgi intermediate compartment (ERGIC) membranes and egress from cells in cargo vesicles. Only a few molecules of the envelope (E) protein are assembled into virions. The role of E in morphogenesis is not fully understood. The cellular localization and dynamics of mouse hepatitis CoV A59 (MHV) E protein were investigated to further understanding of its role during infection. E protein localized in the ERGIC and Golgi with the amino and carboxy termini in the lumen and cytoplasm, respectively. E protein does not traffic to the cell surface. MHV was genetically engineered with a tetracysteine tag at the carboxy end of E. Fluorescence recovery after photobleaching (FRAP) showed that E is mobile in ERGIC/Golgi membranes. Correlative light electron microscopy (CLEM) confirmed the presence of E in Golgi cisternae. The results provide strong support that E proteins carry out their function(s) at the site of budding/assembly. - Highlights: • Mouse hepatitis coronavirus (MHV-CoV) E protein localizes in the ERGIC and Golgi. • MHV-CoV E does not transport to the cell surface. • MHV-CoV can be genetically engineered with a tetracysteine tag appended to E. • First FRAP and correlative light electron microscopy of a CoV E protein. • Live-cell imaging shows that E is mobile in ERGIC/Golgi membranes.

  11. Cytomegalovirus protease targeted prodrug development.

    Science.gov (United States)

    Sabit, Hairat; Dahan, Arik; Sun, Jing; Provoda, Chester J; Lee, Kyung-Dall; Hilfinger, John H; Amidon, Gordon L

    2013-04-01

    Human cytomegalovirus (HCMV) is a prevalent virus that infects up to 90% of the population. The goal of this research is to determine if small molecular prodrug substrates can be developed for a specific HCMV encoded protease and thus achieve site-specific activation. HCMV encodes a 256 amino acid serine protease that is responsible for capsid assembly, an essential process for herpes virus production. The esterase activity of the more stable HCMV A143T/A144T protease mutant was evaluated with model p-nitrophenol (ONp) esters, Boc-Xaa-ONp (Ala, Leu, Ile, Val, Gln, Phe at the Xaa position). We demonstrate that the A143T/A144T mutant has esterase activity toward specific small ester compounds, e.g., Boc-L-Ala-ONp. Mono amino acid and dipeptide prodrugs of ganciclovir (GCV) were also synthesized and evaluated for hydrolysis by the A143T/A144T protease mutant in solution. Hydrolysis of these prodrugs was also evaluated in Caco-2 cell homogenates, human liver microsomes (HLMs), and rat and human plasma. For the selectivity potential of the prodrugs, the hydrolysis ratio was evaluated as a percentage of prodrug hydrolyzed by the HCMV protease over the percentages of prodrug hydrolyses by Caco-2 cell homogenates, HLMs, and human/rat plasma. A dipeptide prodrug of ganciclovir, Ac-l-Gln-l-Ala-GCV, emerged as a potential selective prodrug candidate. The results of this research demonstrate that targeting prodrugs for activation by a specific protease encoded by the infectious HCMV pathogen may be achievable.

  12. Contemporary protease inhibitors and cardiovascular risk

    DEFF Research Database (Denmark)

    Lundgren, Jens; Mocroft, Amanda; Ryom, Lene

    2018-01-01

    PURPOSE OF REVIEW: To review the evidence linking use of HIV protease inhibitors with excess risk of cardiovascular disease (CVD) in HIV+ populations. RECENT FINDINGS: For the two contemporary most frequently used protease inhibitors, darunavir and atazanavir [both pharmacologically boosted...

  13. A genomic survey of proteases in Aspergilli

    NARCIS (Netherlands)

    Budak, Sebnem Ozturkoglu; Zhou, M.; Brouwer, Carlo; Wiebenga, A.; Benoit, Isabelle; Di Falco, Marcos; Tsang, Adrian; de Vries, Ronald P; van den Brink, J.

    2014-01-01

    BACKGROUND: Proteases can hydrolyze peptides in aqueous environments. This property has made proteases the most important industrial enzymes by taking up about 60% of the total enzyme market. Microorganisms are the main sources for industrial protease production due to their high yield and a wide

  14. Curcumin derivatives as HIV-1 protease inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Sui, Z.; Li, J.; Craik, C.S.; Ortiz de Montellano, P.R. [Univ. of California, San Francisco, CA (United States)

    1993-12-31

    Curcumin, a non-toxic natural compound from Curcuma longa, has been found to be an HIV-1 protease inhibitor. Some of its derivatives were synthesized and their inhibitory activity against the HIV-1 protease was tested. Curcumin analogues containing boron enhanced the inhibitory activity. At least of the the synthesized compounds irreversibly inhibits the HIV-1 protease.

  15. tolerant alkaline protease from Bacillus coagulans PSB

    African Journals Online (AJOL)

    oyaide

    2013-05-22

    May 22, 2013 ... suggest the suitability of the enzyme for applications in peptide synthesis, detergent formulation and ... The cell free supernatant was recovered as crude enzyme preparation and used for further studies. Assay of protease activity. Protease activity was ... Effect of pH on growth and protease production.

  16. Identification of Aminopeptidase N as a Cellular Receptor for Human Coronavirus-229E

    Science.gov (United States)

    1992-05-12

    hemagglutinating encephalomyelitis virus (HEV), canine coronavirus (CCV), cat FIPV and feline enteric corona virus (FECV), human CVLPs, mouse...While the cat , dog and pig serve as natural hosts for the other coronavirus group 1 viruses , feline infectious peritonitis virus (FIPV), canine...3 2 . Virus Receptors ••••••••.••••••.....•................ 20 3. Viruses Which Cause Common Colds

  17. Fatal respiratory distress syndrome due to coronavirus infection in a child with severe combined immunodeficiency

    OpenAIRE

    Szczawinska‐Poplonyk, Aleksandra; Jonczyk‐Potoczna, Katarzyna; Breborowicz, Anna; Bartkowska‐Sniatkowska, Alicja; Figlerowicz, Magdalena

    2012-01-01

    Please cite this paper as: Szczawinska‐Poplonyk et al. (2012) Fatal respiratory distress syndrome due to coronavirus infection in a child with severe combined immunodeficiency. Influenza and Other Respiratory Viruses DOI: 10.1111/irv.12059. Coronaviruses have been demonstrated to contribute substantially to respiratory tract infections among the child population. Though infected children commonly present mild upper airway symptoms, in high‐risk patients with underlying conditions, particularl...

  18. Isolation and molecular characterization of type I and type II feline coronavirus in Malaysia

    OpenAIRE

    Amer, Alazawy; Siti Suri, Arshad; Abdul Rahman, Omar; Mohd, Hair Bejo; Faruku, Bande; Saeed, Sharif; Tengku Azmi, Tengku Ibrahim

    2012-01-01

    Abstract Background Feline infectious peritonitis virus (FIPV) and feline enteric coronavirus (FECV) are two important coronaviruses of domestic cat worldwide. Although FCoV is prevalent among cats; the fastidious nature of type I FCoV to grow on cell culture has limited further studies on tissue tropism and pathogenesis of FCoV. While several studies reported serological evidence for FCoV in Malaysia, neither the circulating FCoV isolated nor its biotypes determined. This study for the first...

  19. Factor VII-activating protease

    DEFF Research Database (Denmark)

    Ramanathan, Ramshanker; Gram, Jørgen B; Sand, Niels Peter R

    2017-01-01

    : Factor VII-activating protease (FSAP) may regulate development of cardiovascular disease (CVD). We evaluated sex differences in FSAP measures and examined the association between FSAP and coronary artery calcification (CAC) in a middle-aged population. Participants were randomly selected citizens...

  20. Carbohydrase and protease supplementation increased ...

    African Journals Online (AJOL)

    A trial was conducted to evaluate whether the addition of commercial enzyme preparations containing carbohydrases and a protease would increase the available metabolizable energy (ME) of maize-soya-based broiler diets. Seven thousand five hundred and sixty (7560) day-old Ross 788 chicks were randomly allocated ...

  1. Crystal structure of NL63 respiratory coronavirus receptor-binding domain complexed with its human receptor

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Kailang; Li, Weikai; Peng, Guiqing; Li, Fang; (Harvard-Med); (UMM-MED)

    2010-03-04

    NL63 coronavirus (NL63-CoV), a prevalent human respiratory virus, is the only group I coronavirus known to use angiotensin-converting enzyme 2 (ACE2) as its receptor. Incidentally, ACE2 is also used by group II SARS coronavirus (SARS-CoV). We investigated how different groups of coronaviruses recognize the same receptor, whereas homologous group I coronaviruses recognize different receptors. We determined the crystal structure of NL63-CoV spike protein receptor-binding domain (RBD) complexed with human ACE2. NL63-CoV RBD has a novel {beta}-sandwich core structure consisting of 2 layers of {beta}-sheets, presenting 3 discontinuous receptor-binding motifs (RBMs) to bind ACE2. NL63-CoV and SARS-CoV have no structural homology in RBD cores or RBMs; yet the 2 viruses recognize common ACE2 regions, largely because of a 'virus-binding hotspot' on ACE2. Among group I coronaviruses, RBD cores are conserved but RBMs are variable, explaining how these viruses recognize different receptors. These results provide a structural basis for understanding viral evolution and virus-receptor interactions.

  2. Novel coronavirus and astrovirus in Delaware Bay shorebirds.

    Directory of Open Access Journals (Sweden)

    Kirsi S Honkavuori

    Full Text Available Wild birds are an important but to some extent under-studied reservoir for emerging pathogens. We used unbiased sequencing methods for virus discovery in shorebird samples from the Delaware Bay, USA; an important feeding ground for thousands of migratory birds.Analysis of shorebird fecal samples indicated the presence of a novel astrovirus and coronavirus. A sanderling sample yielded sequences with distant homology to avian nephritis virus 1, an astrovirus associated with acute nephritis in poultry. A ruddy turnstone sample yielded sequences with homology to deltacoronaviruses.Our findings highlight shorebirds as a virus reservoir and the need to closely monitor wild bird populations for the emergence of novel virus variants.

  3. Discovery of a novel bottlenose dolphin coronavirus reveals a distinct species of marine mammal coronavirus in Gammacoronavirus.

    Science.gov (United States)

    Woo, Patrick C Y; Lau, Susanna K P; Lam, Carol S F; Tsang, Alan K L; Hui, Suk-Wai; Fan, Rachel Y Y; Martelli, Paolo; Yuen, Kwok-Yung

    2014-01-01

    While gammacoronaviruses mainly comprise infectious bronchitis virus (IBV) and its closely related bird coronaviruses (CoVs), the only mammalian gammacoronavirus was discovered from a white beluga whale (beluga whale CoV [BWCoV] SW1) in 2008. In this study, we discovered a novel gammacoronavirus from fecal samples from three Indo-Pacific bottlenose dolphins (Tursiops aduncus), which we named bottlenose dolphin CoV (BdCoV) HKU22. All the three BdCoV HKU22-positive samples were collected on the same date, suggesting a cluster of infection, with viral loads of 1 × 10(3) to 1 × 10(5) copies per ml. Clearance of virus was associated with a specific antibody response against the nucleocapsid of BdCoV HKU22. Complete genome sequencing and comparative genome analysis showed that BdCoV HKU22 and BWCoV SW1 have similar genome characteristics and structures. Their genome size is about 32,000 nucleotides, the largest among all CoVs, as a result of multiple unique open reading frames (NS5a, NS5b, NS5c, NS6, NS7, NS8, NS9, and NS10) between their membrane (M) and nucleocapsid (N) protein genes. Although comparative genome analysis showed that BdCoV HKU22 and BWCoV SW1 should belong to the same species, a major difference was observed in the proteins encoded by their spike (S) genes, which showed only 74.3 to 74.7% amino acid identities. The high ratios of the number of synonymous substitutions per synonymous site (Ks) to the number of nonsynonymous substitutions per nonsynonymous site (Ka) in multiple regions of the genome, especially the S gene (Ka/Ks ratio, 2.5), indicated that BdCoV HKU22 may be evolving rapidly, supporting a recent transmission event to the bottlenose dolphins. We propose a distinct species, Cetacean coronavirus, in Gammacoronavirus, to include BdCoV HKU22 and BWCoV SW1, whereas IBV and its closely related bird CoVs represent another species, Avian coronavirus, in Gammacoronavirus.

  4. Coronavirus 3CLpro proteinase cleavage sites: Possible relevance to SARS virus pathology

    Directory of Open Access Journals (Sweden)

    Blom Nikolaj

    2004-06-01

    Full Text Available Abstract Background Despite the passing of more than a year since the first outbreak of Severe Acute Respiratory Syndrome (SARS, efficient counter-measures are still few and many believe that reappearance of SARS, or a similar disease caused by a coronavirus, is not unlikely. For other virus families like the picornaviruses it is known that pathology is related to proteolytic cleavage of host proteins by viral proteinases. Furthermore, several studies indicate that virus proliferation can be arrested using specific proteinase inhibitors supporting the belief that proteinases are indeed important during infection. Prompted by this, we set out to analyse and predict cleavage by the coronavirus main proteinase using computational methods. Results We retrieved sequence data on seven fully sequenced coronaviruses and identified the main 3CL proteinase cleavage sites in polyproteins using alignments. A neural network was trained to recognise the cleavage sites in the genomes obtaining a sensitivity of 87.0% and a specificity of 99.0%. Several proteins known to be cleaved by other viruses were submitted to prediction as well as proteins suspected relevant in coronavirus pathology. Cleavage sites were predicted in proteins such as the cystic fibrosis transmembrane conductance regulator (CFTR, transcription factors CREB-RP and OCT-1, and components of the ubiquitin pathway. Conclusions Our prediction method NetCorona predicts coronavirus cleavage sites with high specificity and several potential cleavage candidates were identified which might be important to elucidate coronavirus pathology. Furthermore, the method might assist in design of proteinase inhibitors for treatment of SARS and possible future diseases caused by coronaviruses. It is made available for public use at our website: http://www.cbs.dtu.dk/services/NetCorona/.

  5. Protease-sensitive synthetic prions.

    Directory of Open Access Journals (Sweden)

    David W Colby

    2010-01-01

    Full Text Available Prions arise when the cellular prion protein (PrP(C undergoes a self-propagating conformational change; the resulting infectious conformer is designated PrP(Sc. Frequently, PrP(Sc is protease-resistant but protease-sensitive (s prions have been isolated in humans and other animals. We report here that protease-sensitive, synthetic prions were generated in vitro during polymerization of recombinant (rec PrP into amyloid fibers. In 22 independent experiments, recPrP amyloid preparations, but not recPrP monomers or oligomers, transmitted disease to transgenic mice (n = 164, denoted Tg9949 mice, that overexpress N-terminally truncated PrP. Tg9949 control mice (n = 174 did not spontaneously generate prions although they were prone to late-onset spontaneous neurological dysfunction. When synthetic prion isolates from infected Tg9949 mice were serially transmitted in the same line of mice, they exhibited sPrP(Sc and caused neurodegeneration. Interestingly, these protease-sensitive prions did not shorten the life span of Tg9949 mice despite causing extensive neurodegeneration. We inoculated three synthetic prion isolates into Tg4053 mice that overexpress full-length PrP; Tg4053 mice are not prone to developing spontaneous neurological dysfunction. The synthetic prion isolates caused disease in 600-750 days in Tg4053 mice, which exhibited sPrP(Sc. These novel synthetic prions demonstrate that conformational changes in wild-type PrP can produce mouse prions composed exclusively of sPrP(Sc.

  6. Cysteine Protease Zymography: Brief Review.

    Science.gov (United States)

    Wilkesman, Jeff

    2017-01-01

    Cysteine proteases play multiple roles in basically all aspects of physiology and development. In plants, they are involved in growth and development and in accumulation and mobilization of storage proteins. Furthermore, they are engaged in signalling pathways and in the response to biotic and abiotic stresses. In animals and also in humans, they are responsible for senescence and apoptosis, prohormone processing, and ECM remodelling. When analyzed by zymography, the enzyme must be renaturated after SDS-PAGE. SDS must be washed out and substituted by Triton X-100. Gels are then further incubated under ideal conditions for activity detection. Cysteine proteases require an acidic pH (5.0-6.0) and a reducing agent, usually DTT. When screening biological samples, there is generally no previous clue on what peptidase class will be present, neither optimal proteolysis conditions are known. Hence, it is necessary to assess several parameters, such as incubation time, pH, temperature, influence of ions or reducing agents, and finally evaluate the inhibition profile. For detection of cysteine peptidase activity, the use of specific inhibitors, such as E-64, can be used to prevent the development of cysteine peptidase activity bands and positively confirm its presence. Here four different protocols to assess cysteine protease activity from different sources are presented.

  7. Genomic characterization of severe acute respiratory syndrome-related coronavirus in European bats and classification of coronaviruses based on partial RNA-dependent RNA polymerase gene sequences

    Czech Academy of Sciences Publication Activity Database

    Drexler, J. F.; Gloza-Rausch, F.; Glende, J.; Corman, V. M.; Muth, D.; Goettsche, M.; Seebens, A.; Niedrig, M.; Pfefferle, S.; Yordanov, S.; Zhelyazkov, L.; Hermanns, U.; Vallo, Peter; Lukashev, A.; Müller, M. A.; Deng, H.; Herrler, G.; Drosten, C.

    2010-01-01

    Roč. 84, č. 21 (2010), s. 11336-11349 ISSN 0022-538X Institutional research plan: CEZ:AV0Z60930519 Keywords : cross-species transmission * SARS-like coronavirus es * reservoir hosts * horseshoe bats Subject RIV: EE - Microbiology, Virology Impact factor: 5.189, year: 2010

  8. Genetic diversity of coronaviruses in bats in Lao PDR and Cambodia.

    Science.gov (United States)

    Lacroix, Audrey; Duong, Veasna; Hul, Vibol; San, Sorn; Davun, Hull; Omaliss, Keo; Chea, Sokha; Hassanin, Alexandre; Theppangna, Watthana; Silithammavong, Soubanh; Khammavong, Kongsy; Singhalath, Sinpakone; Greatorex, Zoe; Fine, Amanda E; Goldstein, Tracey; Olson, Sarah; Joly, Damien O; Keatts, Lucy; Dussart, Philippe; Afelt, Aneta; Frutos, Roger; Buchy, Philippe

    2017-03-01

    South-East Asia is a hot spot for emerging zoonotic diseases, and bats have been recognized as hosts for a large number of zoonotic viruses such as Severe Acute Respiratory Syndrome (SARS), responsible for acute respiratory syndrome outbreaks. Thus, it is important to expand our knowledge of the presence of viruses in bats which could represent a risk to humans. Coronaviruses (CoVs) have been reported in bat species from Thailand, China, Indonesia, Taiwan and the Philippines. However no such work was conducted in Cambodia or Lao PDR. Between 2010 and 2013, 1965 bats were therefore sampled at interfaces with human populations in these two countries. They were tested for the presence of coronavirus by consensus reverse transcription-PCR assay. A total of 93 samples (4.7%) from 17 genera of bats tested positive. Sequence analysis revealed the presence of potentially 37 and 56 coronavirus belonging to alpha-coronavirus (αCoV) and beta-CoV (βCoV), respectively. The βCoVs group is known to include some coronaviruses highly pathogenic to human, such as SARS-CoV and MERS-CoV. All coronavirus sequences generated from frugivorous bats (family Pteropodidae) (n=55) clustered with other bat βCoVs of lineage D, whereas one coronavirus from Pipistrellus coromandra fell in the lineage C of βCoVs which also includes the MERS-CoV. αCoVs were all detected in various genera of insectivorous bats and clustered with diverse bat αCoV sequences previously published. A closely related strain of PEDV, responsible for severe diarrhea in pigs (PEDV-CoV), was detected in 2 Myotis bats. We highlighted the presence and the high diversity of coronaviruses circulating in bats from Cambodia and Lao PDR. Three new bat genera and species were newly identified as host of coronaviruses, namely Macroglossus sp., Megaerops niphanae and Myotis horsfieldii. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Evaluation of serologic and antigenic relationships between middle eastern respiratory syndrome coronavirus and other coronaviruses to develop vaccine platforms for the rapid response to emerging coronaviruses.

    Science.gov (United States)

    Agnihothram, Sudhakar; Gopal, Robin; Yount, Boyd L; Donaldson, Eric F; Menachery, Vineet D; Graham, Rachel L; Scobey, Trevor D; Gralinski, Lisa E; Denison, Mark R; Zambon, Maria; Baric, Ralph S

    2014-04-01

    Middle East respiratory syndrome coronavirus (MERS-CoV) emerged in 2012, causing severe acute respiratory disease and pneumonia, with 44% mortality among 136 cases to date. Design of vaccines to limit the virus spread or diagnostic tests to track newly emerging strains requires knowledge of antigenic and serologic relationships between MERS-CoV and other CoVs.  Using synthetic genomics and Venezuelan equine encephalitis virus replicons (VRPs) expressing spike and nucleocapsid proteins from MERS-CoV and other human and bat CoVs, we characterize the antigenic responses (using Western blot and enzyme-linked immunosorbent assay) and serologic responses (using neutralization assays) against 2 MERS-CoV isolates in comparison with those of other human and bat CoVs.  Serologic and neutralization responses against the spike glycoprotein were primarily strain specific, with a very low level of cross-reactivity within or across subgroups. CoV N proteins within but not across subgroups share cross-reactive epitopes with MERS-CoV isolates. Our findings were validated using a convalescent-phase serum specimen from a patient infected with MERS-CoV (NA 01) and human antiserum against SARS-CoV, human CoV NL63, and human CoV OC43.  Vaccine design for emerging CoVs should involve chimeric spike protein containing neutralizing epitopes from multiple virus strains across subgroups to reduce immune pathology, and a diagnostic platform should include a panel of nucleocapsid and spike proteins from phylogenetically distinct CoVs.

  10. Advances in protease engineering for laundry detergents.

    Science.gov (United States)

    Vojcic, Ljubica; Pitzler, Christian; Körfer, Georgette; Jakob, Felix; Ronny Martinez; Maurer, Karl-Heinz; Schwaneberg, Ulrich

    2015-12-25

    Proteases are essential ingredients in modern laundry detergents. Over the past 30 years, subtilisin proteases employed in the laundry detergent industry have been engineered by directed evolution and rational design to tailor their properties towards industrial demands. This comprehensive review discusses recent success stories in subtilisin protease engineering. Advances in protease engineering for laundry detergents comprise simultaneous improvement of thermal resistance and activity at low temperatures, a rational strategy to modulate pH profiles, and a general hypothesis for how to increase promiscuous activity towards the production of peroxycarboxylic acids as mild bleaching agents. The three protease engineering campaigns presented provide in-depth analysis of protease properties and have identified principles that can be applied to improve or generate enzyme variants for industrial applications beyond laundry detergents. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Early endonuclease-mediated evasion of RNA sensing ensures efficient coronavirus replication.

    Directory of Open Access Journals (Sweden)

    Eveline Kindler

    2017-02-01

    Full Text Available Coronaviruses are of veterinary and medical importance and include highly pathogenic zoonotic viruses, such as SARS-CoV and MERS-CoV. They are known to efficiently evade early innate immune responses, manifesting in almost negligible expression of type-I interferons (IFN-I. This evasion strategy suggests an evolutionary conserved viral function that has evolved to prevent RNA-based sensing of infection in vertebrate hosts. Here we show that the coronavirus endonuclease (EndoU activity is key to prevent early induction of double-stranded RNA (dsRNA host cell responses. Replication of EndoU-deficient coronaviruses is greatly attenuated in vivo and severely restricted in primary cells even during the early phase of the infection. In macrophages we found immediate induction of IFN-I expression and RNase L-mediated breakdown of ribosomal RNA. Accordingly, EndoU-deficient viruses can retain replication only in cells that are deficient in IFN-I expression or sensing, and in cells lacking both RNase L and PKR. Collectively our results demonstrate that the coronavirus EndoU efficiently prevents simultaneous activation of host cell dsRNA sensors, such as Mda5, OAS and PKR. The localization of the EndoU activity at the site of viral RNA synthesis-within the replicase complex-suggests that coronaviruses have evolved a viral RNA decay pathway to evade early innate and intrinsic antiviral host cell responses.

  12. Genomic Analysis and Surveillance of the Coronavirus Dominant in Ducks in China.

    Directory of Open Access Journals (Sweden)

    Qing-Ye Zhuang

    Full Text Available The genetic diversity, evolution, distribution, and taxonomy of some coronaviruses dominant in birds other than chickens remain enigmatic. In this study we sequenced the genome of a newly identified coronavirus dominant in ducks (DdCoV, and performed a large-scale surveillance of coronaviruses in chickens and ducks using a conserved RT-PCR assay. The viral genome harbors a tandem repeat which is rare in vertebrate RNA viruses. The repeat is homologous to some proteins of various cellular organisms, but its origin remains unknown. Many substitutions, insertions, deletions, and some frameshifts and recombination events have occurred in the genome of the DdCoV, as compared with the coronavirus dominant in chickens (CdCoV. The distances between DdCoV and CdCoV are large enough to separate them into different species within the genus Gammacoronavirus. Our surveillance demonstrated that DdCoVs and CdCoVs belong to different lineages and occupy different ecological niches, further supporting that they should be classified into different species. Our surveillance also demonstrated that DdCoVs and CdCoVs are prevalent in live poultry markets in some regions of China. In conclusion, this study shed novel insight into the genetic diversity, evolution, distribution, and taxonomy of the coronaviruses circulating in chickens and ducks.

  13. Structure of the C-terminal domain of nsp4 from feline coronavirus

    International Nuclear Information System (INIS)

    Manolaridis, Ioannis; Wojdyla, Justyna A.; Panjikar, Santosh; Snijder, Eric J.; Gorbalenya, Alexander E.; Berglind, Hanna; Nordlund, Pär; Coutard, Bruno; Tucker, Paul A.

    2009-01-01

    The structure of the cytosolic C-terminal domain of nonstructural protein 4 from feline coronavirus has been determined and analyzed. Coronaviruses are a family of positive-stranded RNA viruses that includes important pathogens of humans and other animals. The large coronavirus genome (26–31 kb) encodes 15–16 nonstructural proteins (nsps) that are derived from two replicase polyproteins by autoproteolytic processing. The nsps assemble into the viral replication–transcription complex and nsp3, nsp4 and nsp6 are believed to anchor this enzyme complex to modified intracellular membranes. The largest part of the coronavirus nsp4 subunit is hydrophobic and is predicted to be embedded in the membranes. In this report, a conserved C-terminal domain (∼100 amino-acid residues) has been delineated that is predicted to face the cytoplasm and has been isolated as a soluble domain using library-based construct screening. A prototypical crystal structure at 2.8 Å resolution was obtained using nsp4 from feline coronavirus. Unmodified and SeMet-substituted proteins were crystallized under similar conditions, resulting in tetragonal crystals that belonged to space group P4 3 . The phase problem was initially solved by single isomorphous replacement with anomalous scattering (SIRAS), followed by molecular replacement using a SIRAS-derived composite model. The structure consists of a single domain with a predominantly α-helical content displaying a unique fold that could be engaged in protein–protein interactions

  14. Structure of the C-terminal domain of nsp4 from feline coronavirus

    Energy Technology Data Exchange (ETDEWEB)

    Manolaridis, Ioannis; Wojdyla, Justyna A.; Panjikar, Santosh [EMBL Hamburg Outstation, c/o DESY, Notkestrasse 85, D-22603 Hamburg (Germany); Snijder, Eric J.; Gorbalenya, Alexander E. [Molecular Virology Laboratory, Department of Medical Microbiology, Center of Infectious Diseases, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden (Netherlands); Berglind, Hanna; Nordlund, Pär [Division of Biophysics, Department of Medical Biochemistry and Biophysics, Scheeles väg 2, Karolinska Institute, SE-171 77 Stockholm (Sweden); Coutard, Bruno [Laboratoire Architecture et Fonction des Macromolécules Biologiques, UMR 6098, AFMB-CNRS-ESIL, Case 925, 163 Avenue de Luminy, 13288 Marseille (France); Tucker, Paul A., E-mail: tucker@embl-hamburg.de [EMBL Hamburg Outstation, c/o DESY, Notkestrasse 85, D-22603 Hamburg (Germany)

    2009-08-01

    The structure of the cytosolic C-terminal domain of nonstructural protein 4 from feline coronavirus has been determined and analyzed. Coronaviruses are a family of positive-stranded RNA viruses that includes important pathogens of humans and other animals. The large coronavirus genome (26–31 kb) encodes 15–16 nonstructural proteins (nsps) that are derived from two replicase polyproteins by autoproteolytic processing. The nsps assemble into the viral replication–transcription complex and nsp3, nsp4 and nsp6 are believed to anchor this enzyme complex to modified intracellular membranes. The largest part of the coronavirus nsp4 subunit is hydrophobic and is predicted to be embedded in the membranes. In this report, a conserved C-terminal domain (∼100 amino-acid residues) has been delineated that is predicted to face the cytoplasm and has been isolated as a soluble domain using library-based construct screening. A prototypical crystal structure at 2.8 Å resolution was obtained using nsp4 from feline coronavirus. Unmodified and SeMet-substituted proteins were crystallized under similar conditions, resulting in tetragonal crystals that belonged to space group P4{sub 3}. The phase problem was initially solved by single isomorphous replacement with anomalous scattering (SIRAS), followed by molecular replacement using a SIRAS-derived composite model. The structure consists of a single domain with a predominantly α-helical content displaying a unique fold that could be engaged in protein–protein interactions.

  15. Proteolytic crosstalk in multi-protease networks

    Science.gov (United States)

    Ogle, Curtis T.; Mather, William H.

    2016-04-01

    Processive proteases, such as ClpXP in E. coli, are conserved enzyme assemblies that can recognize and rapidly degrade proteins. These proteases are used for a number of purposes, including degrading mistranslated proteins and controlling cellular stress response. However, proteolytic machinery within the cell is limited in capacity and can lead to a bottleneck in protein degradation, whereby many proteins compete (‘queue’) for proteolytic resources. Previous work has demonstrated that such queueing can lead to pronounced statistical relationships between different protein counts when proteins compete for a single common protease. However, real cells contain many different proteases, e.g. ClpXP, ClpAP, and Lon in E. coli, and it is not clear how competition between proteins for multiple classes of protease would influence the dynamics of cellular networks. In the present work, we theoretically demonstrate that a multi-protease proteolytic bottleneck can substantially couple the dynamics for both simple and complex (oscillatory) networks, even between substrates with substantially different affinities for protease. For these networks, queueing often leads to strong positive correlations between protein counts, and these correlations are strongest near the queueing theoretic point of balance. Furthermore, we find that the qualitative behavior of these networks depends on the relative size of the absolute affinity of substrate to protease compared to the cross affinity of substrate to protease, leading in certain regimes to priority queue statistics.

  16. [Prevalence and clinical characteristics of coronavirus NL63 infection in children hospitalized for acute lower respiratory tract infections in Changsha].

    Science.gov (United States)

    Zhang, Fei; Zhang, Bing; Xie, Zhi-Ping; Gao, Han-Chun; Zhao, Xin; Zhong, Li-Li; Zhou, Qiong-Hua; Hou, Yun-De; Duan, Zhao-Jun

    2012-04-01

    The main objective of this study was to explore the prevalence and clinical characteristics of human coronavirus NL63 infection in hospitalized children with acute lower respiratory tract infection (ALRTI) in Changsha. Nasopharyngeal aspirates (NPA) samples were collected from 1185 hospitalized children with ALRTI at the People's Hospital of Hunan province, between September 2008 and October 2010. Reverse transcriptase polymerase chain reaction (RT-PCR) was employed to screen for coronavirus NL63, which is a 255 bp fragment of a part of N gene. All positive amplification products were confirmed by sequencing and compared with those in GenBank. The overall frequency of coronavirus NL63 infection was 0.8%, 6 (60%) out of the coronavirus NL63 positive patients were detected in summer, 2 in autumn, 1 in spring and winter, respectively. The patients were from 2 months to two and a half years old. The clinical diagnosis was bronchopneumonia (60%), bronchiolitis (30%), and acute laryngotracheal bronchitis (10%). Four of the 10 cases had critical illness, 4 cases had underlying diseases, and 7 cases had mixed infection with other viruses. The homogeneity of coronavirus NL63 with those published in the GenBank at nucleotide levels was 97%-100%. Coronavirus NL63 infection exists in hospitalized children with acute lower respiratory tract infection in Changsha. Coronavirus NL63 infections are common in children under 3 years of age. There is significant difference in the infection rate between the boys and the girls: the boys had higher rate than the girls. The peak of prevalence of the coronavirus NL63 was in summer. A single genetic lineage of coronavirus NL63 was revealed in human subjects in Changsha. Coronavirus NL63 may also be one of the lower respiratory pathogen in China.

  17. Coronaviruses in guano from Pteropus medius bats in Peradeniya, Sri Lanka.

    Science.gov (United States)

    Kudagammana, H D W S; Thevanesam, V; Chu, D K W; Eriyagama, N B; Peiris, J S M; Noordeen, F

    2018-03-02

    Bats are a unique group of mammals well suited to be hosts for emerging viruses. With current rates of deforestation and urbanization, redistribution of bat habitats to urban and suburban areas may bring bats into closer contact with livestock and humans. Common flying fox, Pteropus medius (previously known as Pteropus giganteus), forms large communal roosts on treetops, often in close proximity to human habitation in Sri Lanka. This report describes the detection of coronavirus RNA in P. medius bat guano collected in Peradeniya, Sri Lanka. These viruses had >97% nucleotide identity with coronaviruses detected in Cynopterus sphinx, Scotophilus heathii and S. kuhlii bats in Thailand. Pteropus medius is widespread in Asia and appears to excrete group D coronaviruses, which are hitherto confined to bats; however, these findings may have public health implications in the future. © 2018 Blackwell Verlag GmbH.

  18. Human Coronaviruses 229E and NL63: Close Yet Still So Far

    Directory of Open Access Journals (Sweden)

    Ronald Dijkman

    2009-04-01

    Full Text Available HCoV-NL63 and HCoV-229E are two of the four human coronaviruses that circulate worldwide. These two viruses are unique in their relationship towards each other. Phylogenetically, the viruses are more closely related to each other than to any other human coronavirus, yet they only share 65% sequence identity. Moreover, the viruses use different receptors to enter their target cell. HCoV-NL63 is associated with croup in children, whereas all signs suggest that the virus probably causes the common cold in healthy adults. HCoV-229E is a proven common cold virus in healthy adults, so it is probable that both viruses induce comparable symptoms in adults, even though their mode of infection differs. Here, we present an overview of the current knowledge on both human coronaviruses, focusing on similarities and differences.

  19. Proteomic analysis of purified coronavirus infectious bronchitis virus particles

    Directory of Open Access Journals (Sweden)

    Shu Dingming

    2010-06-01

    Full Text Available Abstract Background Infectious bronchitis virus (IBV is the coronavirus of domestic chickens causing major economic losses to the poultry industry. Because of the complexity of the IBV life cycle and the small number of viral structural proteins, important virus-host relationships likely remain to be discovered. Toward this goal, we performed two-dimensional gel electrophoresis fractionation coupled to mass spectrometry identification approaches to perform a comprehensive proteomic analysis of purified IBV particles. Results Apart from the virus-encoded structural proteins, we detected 60 host proteins in the purified virions which can be grouped into several functional categories including intracellular trafficking proteins (20%, molecular chaperone (18%, macromolcular biosynthesis proteins (17%, cytoskeletal proteins (15%, signal transport proteins (15%, protein degradation (8%, chromosome associated proteins (2%, ribosomal proteins (2%, and other function proteins (3%. Interestingly, 21 of the total host proteins have not been reported to be present in virions of other virus families, such as major vault protein, TENP protein, ovalbumin, and scavenger receptor protein. Following identification of the host proteins by proteomic methods, the presence of 4 proteins in the purified IBV preparation was verified by western blotting and immunogold labeling detection. Conclusions The results present the first standard proteomic profile of IBV and may facilitate the understanding of the pathogenic mechanisms.

  20. Suppression of feline coronavirus replication in vitro by cyclosporin A

    Directory of Open Access Journals (Sweden)

    Tanaka Yoshikazu

    2012-04-01

    Full Text Available Abstract The feline infectious peritonitis virus (FIPV is a member of the feline coronavirus family that causes FIP, which is incurable and fatal in cats. Cyclosporin A (CsA, an immunosuppressive agent that targets the nuclear factor pathway of activated T-cells (NF-AT to bind cellular cyclophilins (CyP, dose-dependently inhibited FIPV replication in vitro. FK506 (an immunosuppressor of the pathway that binds cellular FK506-binding protein (FKBP but not CyP did not affect FIPV replication. Neither cell growth nor viability changed in the presence of either CsA or FK506, and these factors did not affect the NF-AT pathway in fcwf-4 cells. Therefore, CsA does not seem to exert inhibitory effects via the NF-AT pathway. In conclusion, CsA inhibited FIPV replication in vitro and further studies are needed to verify the practical value of CsA as an anti-FIPV treatment in vivo.

  1. Middle East Respiratory Syndrome (MERS) coronavirus seroprevalence in domestic livestock in Saudi Arabia, 2010 to 2013.

    Science.gov (United States)

    Hemida, M G; Perera, R A; Wang, P; Alhammadi, M A; Siu, L Y; Li, M; Poon, L L; Saif, L; Alnaeem, A; Peiris, M

    2013-12-12

    In Saudi Arabia, including regions of Riyadh and Al Ahsa, pseudoparticle neutralisation (ppNT) and microneutralisation (MNT) tests detected no antibodies to Middle East Respiratory Syndrome coronavirus (MERS-CoV) in sheep (n= 100), goats (n= 45), cattle (n= 50) and chickens (n= 240). Dromedary camels however, had a high prevalence of MERS-CoV antibodies. Bovine coronavirus (BCoV) infected sera from cattle had no cross-reactivity in MERS-CoV ppNT or MNT, while many dromedary camels’ sera reacted to both BCoV and MERS-CoV. Some nevertheless displayed specific serologic reaction profiles to MERS-CoV.

  2. Optimization of alkaline protease production from Pseudomonas ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-12-15

    Dec 15, 2009 ... protease production was 37°C at pH 9, with 2% inoculum in the medium for 24 h. .... Positive. Catalase test. Positive ... The enzyme activity gradually decreases from ... Effect of temperature on protease production by Pseudomonas fluorescens. 0 .... between RNA polymerase and upstream promotes DNA.

  3. Purification and characterization of protease enzyme from ...

    African Journals Online (AJOL)

    user

    2013-03-20

    Mar 20, 2013 ... Full Length Research Paper. Purification and ... ting into small peptides and free amino acids, which can ... Isolated strain was cultured in synthetic medium- casein (SMC; ... Protease activity was assayed by sigma's non-specific protease ... following buffers: 0.05 M citrate-phosphate buffer (pH 5 to 6), Tris-.

  4. Current and Novel Inhibitors of HIV Protease

    Czech Academy of Sciences Publication Activity Database

    Pokorná, Jana; Machala, L.; Řezáčová, Pavlína; Konvalinka, Jan

    2009-01-01

    Roč. 1, č. 3 (2009), s. 1209-1239 ISSN 1999-4915 R&D Projects: GA MŠk 1M0508 Grant - others:GA AV ČR(CZ) IAAX00320901 Program:IA Institutional research plan: CEZ:AV0Z40550506 Keywords : HIV protease * protease inhibitor * HAART Subject RIV: CE - Biochemistry

  5. Common RNA replication signals exist among group 2 coronaviruses: evidence for in vivo recombination between animal and human coronavius molecules

    International Nuclear Information System (INIS)

    Wu, H.-Y.; Guy, James S.; Yoo, Dongwan; Vlasak, Reinhard; Urbach, Ena; Brian, David A.

    2003-01-01

    5' and 3' UTR sequences on the coronavirus genome are known to carry cis-acting elements for DI RNA replication and presumably also virus genome replication. 5' UTR-adjacent coding sequences are also thought to harbor cis-acting elements. Here we have determined the 5' UTR and adjacent 289-nt sequences, and 3' UTR sequences, for six group 2 coronaviruses and have compared them to each other and to three previously reported group 2 members. Extensive regions of highly similar UTR sequences were found but small regions of divergence were also found indicating group 2 coronaviruses could be subdivided into those that are bovine coronavirus (BCoV)-like (BCoV, human respiratory coronavirus-OC43, human enteric coronavirus, porcine hemagglutinating encephalomyelitis virus, and equine coronavirus) and those that are murine hepatitis virus (MHV)-like (A59, 2, and JHM strains of MHV, puffinosis virus, and rat sialodacryoadenitis virus). The 3' UTRs of BCoV and MHV have been previously shown to be interchangeable. Here, a reporter-containing BCoV DI RNA was shown to be replicated by all five BCoV-like helper viruses and by MHV-H2 (a human cell-adapted MHV strain), a representative of the MHV-like subgroup, demonstrating group 2 common 5' and 3' replication signaling elements. BCoV DI RNA, furthermore, acquired the leader of HCoV-OC43 by leader switching, demonstrating for the first time in vivo recombination between animal and human coronavirus molecules. These results indicate that common replication signaling elements exist among group 2 coronaviruses despite a two-cluster pattern within the group and imply there could exist a high potential for recombination among group members

  6. Experimental inoculation of equine coronavirus into Japanese draft horses.

    Science.gov (United States)

    Nemoto, Manabu; Oue, Yasuhiro; Morita, Yoshinori; Kanno, Toru; Kinoshita, Yuta; Niwa, Hidekazu; Ueno, Takanori; Katayama, Yoshinari; Bannai, Hiroshi; Tsujimura, Koji; Yamanaka, Takashi; Kondo, Takashi

    2014-12-01

    Recently, outbreaks associated with equine coronavirus (ECoV) have occurred in Japan and the United States. While ECoV is likely to be pathogenic to horses, it has not been shown that experimental inoculation of horses with ECoV produces clinical signs of disease. In this study, we inoculated three Japanese draft horses with an ECoV-positive diarrheic fecal sample to confirm infection after inoculation and to investigate the clinical course and virus shedding patterns of ECoV. Virus neutralization tests showed that all three horses became infected with ECoV. Two of the three horses developed clinical signs similar to those observed during ECoV outbreaks, including fever, anorexia, and gastrointestinal dysfunction. All horses excreted a large amount of virus into their feces for more than 9 days after inoculation regardless of the presence or absence of clinical signs, which suggests that feces are an important source of ECoV infection. ECoV was also detected in nasal swabs from all horses, suggesting that respiratory transmission of ECoV may occur. Both symptomatic horses developed viremia, while the asymptomatic horse did not. White blood cell counts and serum amyloid A concentrations changed relative to the clinical condition of the inoculated horses; these may be useful markers for monitoring the clinical status of horses infected with ECoV. This is the first report of induction of clinical signs of ECoV infection in horses by experimental inoculation. These clinical and virological findings should aid further investigation of the pathogenesis of ECoV.

  7. Human coronavirus and severe acute respiratory infection in Southern Brazil.

    Science.gov (United States)

    Trombetta, Hygor; Faggion, Heloisa Z; Leotte, Jaqueline; Nogueira, Meri B; Vidal, Luine R R; Raboni, Sonia M

    2016-05-01

    Human coronaviruses (HCoVs) are an important cause of respiratory tract infection and are responsible for causing the common cold in the general population. Thus, adequate surveillance of HCoV is essential. This study aimed to analyze the impact of HCoV infections and their relation to severe acute respiratory infection (SARI) in a hospitalized population in Southern Brazil. A cross-sectional study was conducted at a tertiary care hospital, and assessed inpatients under investigation for SARI by the hospital epidemiology department, and all patients who had nasopharyngeal aspirates collected from January 2012 to December 2013 to detect respiratory viruses (RVs). Viral infection was detected by multiplex reverse transcriptase polymerase chain reaction (RT-PCR), with primers specific to the subtypes HCoV-229E/NL63 and OC43/HKU1. The overall positivity rate was 58.8% (444/755), and HCoVs were detected in 7.6% (n = 34) of positive samples. Children below two years of age were most frequently affected (62%). Comorbidities were more likely to be associated with HCoVs than with other RVs. Immunosuppression was an independent risk factor for HCoV infection (OR = 3.5, 95% CI 1.6-7.6). Dyspnea was less frequently associated with HCoV infection (p infected with HCoV (9%) died from respiratory infection. HCoVs are important respiratory pathogens, especially in hospitalized children under 2 years of age and in immunosuppressed patients. They may account for a small proportion of SARI diagnoses, increased need for mechanical ventilation, intensive care unit admission, and death.

  8. A reverse genetics system for avian coronavirus infectious bronchitis virus based on targeted RNA recombination

    NARCIS (Netherlands)

    van Beurden, Steven J; Berends, Alinda J; Krämer-Kühl, Annika; Spekreijse, Dieuwertje; Chénard, Gilles; Philipp, Hans-Christian; Mundt, Egbert; Rottier, Peter J M; Verheije, M Hélène

    2017-01-01

    BACKGROUND: Avian coronavirus infectious bronchitis virus (IBV) is a respiratory pathogen of chickens that causes severe economic losses in the poultry industry worldwide. Major advances in the study of the molecular biology of IBV have resulted from the development of reverse genetics systems for

  9. MERS Coronavirus Neutralizing Antibodies in Camels, Eastern Africa, 1983-1997

    NARCIS (Netherlands)

    Müller, Marcel A; Corman, Victor Max; Jores, Joerg; Meyer, Benjamin; Younan, Mario; Liljander, Anne; Bosch, Berend-Jan; Lattwein, Erik; Hilali, Mosaad; Musa, Bakri E; Bornstein, Set; Drosten, Christian

    2014-01-01

    To analyze the distribution of Middle East respiratory syndrome coronavirus (MERS-CoV)-seropositive dromedary camels in eastern Africa, we tested 189 archived serum samples accumulated during the past 30 years. We identified MERS-CoV neutralizing antibodies in 81.0% of samples from the main

  10. Human Infection with MERS coronavirus after exposure to infected camels, Saudi Arabia, 2013

    NARCIS (Netherlands)

    Memish, Ziad A.; Cotten, Matthew; Meyer, Benjamin; Watson, Simon J.; Alsahafi, Abdullah J.; Al Rabeeah, Abdullah A.; Corman, Victor Max; Sieberg, Andrea; Makhdoom, Hatem Q.; Assiri, Abdullah; Al Masri, Malaki; Aldabbagh, Souhaib; Bosch, Berend Jan|info:eu-repo/dai/nl/273306049; Beer, Martin; Müller, Marcel A.; Kellam, Paul; Drosten, Christian

    2014-01-01

    We investigated a case of human infection with Middle East respiratory syndrome coronavirus (MERS-CoV) after exposure to infected camels. Analysis of the whole human-derived virus and 15% of the camel-derived virus sequence yielded nucleotide polymorphism signatures suggestive of cross-species

  11. Middle East respiratory syndrome coronavirus in dromedary camels: An outbreak investigation

    NARCIS (Netherlands)

    B.L. Haagmans (Bart); S.H.S. Al Dhahiry (Said); C.B.E.M. Reusken (Chantal); V.S. Raj (Stalin); M. Galiano (Monica); R.H. Myers (Richard); G-J. Godeke (Gert-Jan); M. Jonges (Marcel); E. Farag (Elmoubasher); A. Diab (Ayman); H. Ghobashy (Hazem); F. Alhajri (Farhoud); M. Al-Thani (Mohamed); S.A. Al-Marri (Salih); H.E. Al Romaihi (Hamad); A. Al Khal (Abdullatif); A. Bermingham (Alison); A.D.M.E. Osterhaus (Albert); M.M. AlHajri (Mohd); M.P.G. Koopmans D.V.M. (Marion)

    2014-01-01

    textabstractBackground: Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe lower respiratory tract infection in people. Previous studies suggested dromedary camels were a reservoir for this virus. We tested for the presence of MERS-CoV in dromedary camels from a farm in Qatar

  12. The emerging novel Middle East respiratory syndrome coronavirus: The “knowns” and “unknowns”

    Directory of Open Access Journals (Sweden)

    Jasper Fuk-Woo Chan

    2013-07-01

    Full Text Available A novel lineage C betacoronavirus, originally named human coronavirus EMC/2012 (HCoV-EMC and recently renamed Middle East respiratory syndrome coronavirus (MERS-CoV, that is phylogenetically closely related to Tylonycteris bat coronavirus HKU4 and Pipistrellus bat coronavirus HKU5, which we discovered in 2007 from bats in Hong Kong, has recently emerged in the Middle East to cause a severe acute respiratory syndrome (SARS-like infection in humans. The first laboratory-confirmed case, which involved a 60-year-old man from Bisha, the Kingdom of Saudi Arabia (KSA, who died of rapidly progressive community-acquired pneumonia and acute renal failure, was announced by the World Health Organization (WHO on September 23, 2012. Since then, a total of 70 cases, including 39 fatalities, have been reported in the Middle East and Europe. Recent clusters involving epidemiologically-linked household contacts and hospital contacts in the Middle East, Europe, and Africa strongly suggested possible human-to-human transmission. Clinical and laboratory research data generated in the past few months have provided new insights into the possible animal reservoirs, transmissibility, and virulence of MERS-CoV, and the optimal laboratory diagnostic options and potential antiviral targets for MERS-CoV-associated infection.

  13. Antibodies against MERS coronavirus in dromedaries, United Arab Emirates, 2003 and 2013

    NARCIS (Netherlands)

    Meyer, Benjamin; Müller, Marcel A.; Corman, Victor M.; Reusken, Chantal B E M; Ritz, Daniel; Godeke, Gert Jan; Lattwein, Erik; Kallies, Stephan; Siemens, Artem; van Beek, Janko; Drexler, Jan F.; Muth, Doreen; Bosch, Berend Jan; Wernery, Ulrich; Koopmans, Marion P G; Wernery, Renate; Drosten, Christian

    2014-01-01

    Middle East respiratory syndrome coronavirus (MERS-CoV) has caused an ongoing outbreak of severe acute respiratory tract infection in humans in the Arabian Peninsula since 2012. Dromedary camels have been implicated as possible viral reservoirs. We used serologic assays to analyze 651 dromedary

  14. Middle East Respiratory Coronavirus Accessory Protein 4a Inhibits PKR-Mediated Antiviral Stress Responses

    NARCIS (Netherlands)

    Rabouw, Huib H; Langereis, Martijn A; Knaap, Robert C M; Dalebout, Tim J; Canton, Javier; Sola, Isabel; Enjuanes, Luis; Bredenbeek, Peter J; Kikkert, Marjolein; de Groot, Raoul J; van Kuppeveld, Frank J M

    2016-01-01

    Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe respiratory infections that can be life-threatening. To establish an infection and spread, MERS-CoV, like most other viruses, must navigate through an intricate network of antiviral host responses. Besides the well-known type I

  15. Characterization of a novel coronavirus associated with severe acute respiratory syndrome

    NARCIS (Netherlands)

    P.A. Rota (Paul); M.S. Oberste (Steven); S.S. Monroe (Stephan); W.A. Nix (Allan); R. Campagnoli (Ray); J.P. Icenogle (Joseph); S. Penaranda; B. Bankamp (Bettina); K. Maher (Kaija); M.H. Chen (Min-hsin); S. Tong (Suxiong); A. Tamin (Azaibi); L. Lowe (Luis); M. Frace (Michael); J.L. DeRisi (Joseph); Q. Chen (Qi); D. Wang (David); D.D. Erdman (Dean); T.C. Peret (Teresa); C. Burns (Cara); T.G. Ksiazek (Thomas); P.E. Rollin (Pierre); A. Sanchez (Berenguer); S. Liffick (Stephanie); B. Holloway (Brian); J. Limor (Josef); K. McCaustland (Karen); M. Olsen-Rasmussen (Mellissa); S. Gunther; A.D.M.E. Osterhaus (Albert); C. Drosten (Christian); M.A. Pallansch (Mark); L.J. Anderson (Larry); W.J. Belline; R.A.M. Fouchier (Ron)

    2003-01-01

    textabstractIn March 2003, a novel coronavirus (SARS-CoV) was discovered in association with cases of severe acute respiratory syndrome (SARS). The sequence of the complete genome of SARS-CoV was determined, and the initial characterization of the viral genome is presented in this report. The

  16. A Structural analysis of M protein in coronavirus assembly and morphology

    DEFF Research Database (Denmark)

    W. Neuman, Benjamin; Kiss, Gabriella; H. Kunding, Andreas

    2011-01-01

    The M protein of coronavirus plays a central role in virus assembly, turning cellular membranes into workshops where virus and host factors come together to make new virus particles. We investigated how M structure and organization is related to virus shape and size using cryo-electron microscopy...... protein functions to promote virus assembly....

  17. Sequence evidence for RNA recombination in field isolates of avian coronavirus infectious bronchitis virus

    NARCIS (Netherlands)

    Kusters, J G; Jager, E J; Niesters, H G; van der Zeijst, B A

    1990-01-01

    Under laboratory conditions coronaviruses were shown to have a high frequency of recombination. In The Netherlands, vaccination against infectious bronchitis virus (IBV) is performed with vaccines that contain several life-attenuated virus strains. These highly effective vaccines may create ideal

  18. Severe acute respiratory syndrome--a new coronavirus from the Chinese dragon's lair

    DEFF Research Database (Denmark)

    Knudsen, T B; Kledal, T N; Andersen, O

    2003-01-01

    current worldwide distribution. The concerted efforts of a globally united scientific community have led to the independent isolation and identification of a novel coronavirus from SARS patients by several groups. The extraordinarily rapid isolation of a causative agent of this newly emerged infectious...

  19. Evidence for an Ancestral Association of Human Coronavirus 229E with Bats

    NARCIS (Netherlands)

    Corman, Victor Max; Baldwin, Heather J.; Tateno, Adriana Fumie; Zerbinati, Rodrigo Melim; Annan, Augustina; Owusu, Michael; Nkrumah, Evans Ewald; Maganga, Gael Darren; Oppong, Samuel; Adu-Sarkodie, Yaw; Vallo, Peter; da Silva Filho, Luiz Vicente Ribeiro Ferreira; Leroy, Eric M.; Thiel, Volker; van der Hoek, Lia; Poon, Leo L. M.; Tschapka, Marco; Drosten, Christian; Drexler, Jan Felix

    2015-01-01

    We previously showed that close relatives of human coronavirus 229E (HCoV-229E) exist in African bats. The small sample and limited genomic characterizations have prevented further analyses so far. Here, we tested 2,087 fecal specimens from 11 bat species sampled in Ghana for HCoV-229E-related

  20. Seroprevalence and risk factors for infection with equine coronavirus in healthy horses in the USA

    NARCIS (Netherlands)

    Kooijman, L.J.; James, K.; Mapes, S.M.; Theelen, M.J.P.; Pusterla, N.

    2017-01-01

    Equine coronavirus (ECoV) is considered an enteric pathogen of foals and has only recently been associated with infections in adult horses. Seroprevalence data is needed to better understand the epidemiology of ECoV in adult horses, evaluate diagnostic modalities and develop preventive measures. The

  1. Clinical, hematological, and biochemical findings in puppies with coronavirus and parvovirus enteritis

    Science.gov (United States)

    Castro, Tatiana X.; Cubel Garcia, Rita de Cássia N.; Gonçalves, Luciana P. S.; Costa, Erika M.; Marcello, Gracy C.G.; Labarthe, Norma V.; Mendes-de-Almeida, Flavya

    2013-01-01

    The clinical and laboratory findings in puppies naturally infected with canine coronavirus (CCoV) and/or canine parvovirus (CPV) were compared with findings in uninfected puppies. Lymphopenia was the only parameter related to CCoV infection that was statistically significant; vomiting, anorexia, lethargy, hemorrhagic fluid diarrhea, leukopenia, lymphopenia, thrombocytopenia, hypoglycemia, and hypoproteinemia were correlated with CPV infection. PMID:24155496

  2. Molecular dynamics of Middle East Respiratory Syndrome Coronavirus (MERS CoV) fusion heptad repeat trimers

    KAUST Repository

    Kandeel, Mahmoud; Al-Taher, Abdulla; Li, Huifang; Schwingenschlö gl, Udo; Alnazawi, Mohamed

    2018-01-01

    Structural studies related to Middle East Respiratory Syndrome Coronavirus (MERS CoV) infection process are so limited. In this study, molecular dynamics (MD) simulation was carried out to unravel changes in the MERS CoV heptad repeat domains (HRs

  3. Qualitative and quantitative ultrastructural analysis of the membrane rearrangements induced by coronavirus

    NARCIS (Netherlands)

    Ulasli, M.; Verheije, M.H.; de Haan, C.A.M.; Reggiori, F.M.

    2011-01-01

    Coronaviruses (CoV) are enveloped positive-strand RNA viruses that induce different membrane rearrangements in infected cells in order to efficiently replicate and assemble. The origin, the protein composition and the function of these structures are not well established. To shed further light on

  4. Middle East Respiratory Syndrome Coronavirus Antibodies in Dromedary Camels, Bangladesh, 2015

    Science.gov (United States)

    Islam, Ariful; Rostal, Melinda K.; Islam, Shariful; Rahman, Mohammed Ziaur; Hossain, Mohammed Enayet; Uzzaman, Mohammed Salim; Munster, Vincent J.; Peiris, Malik; Flora, Meerjady Sabrina; Rahman, Mahmudur; Daszak, Peter

    2018-01-01

    Dromedary camels are bred domestically and imported into Bangladesh. In 2015, of 55 camels tested for Middle East respiratory syndrome coronavirus in Dhaka, 17 (31%) were seropositive, including 1 bred locally. None were PCR positive. The potential for infected camels in urban markets could have public health implications and warrants further investigation. PMID:29664373

  5. The first complete genome sequences of clinical isolates of human coronavirus 229E

    NARCIS (Netherlands)

    Farsani, Seyed Mohammad Jazaeri; Dijkman, Ronald; Jebbink, Maarten F.; Goossens, Herman; Ieven, Margareta; Deijs, Martin; Molenkamp, Richard; van der Hoek, Lia

    2012-01-01

    Human coronavirus 229E has been identified in the mid-1960s, yet still only one full-genome sequence is available. This full-length sequence has been determined from the cDNA-clone Inf-1 that is based on the lab-adapted strain VR-740. Lab-adaptation might have resulted in genomic changes, due to

  6. A biotechnology perspective of fungal proteases

    Directory of Open Access Journals (Sweden)

    Paula Monteiro de Souza

    2015-06-01

    Full Text Available Proteases hydrolyze the peptide bonds of proteins into peptides and amino acids, being found in all living organisms, and are essential for cell growth and differentiation. Proteolytic enzymes have potential application in a wide number of industrial processes such as food, laundry detergent and pharmaceutical. Proteases from microbial sources have dominated applications in industrial sectors. Fungal proteases are used for hydrolyzing protein and other components of soy beans and wheat in soy sauce production. Proteases can be produced in large quantities in a short time by established methods of fermentation. The parameters such as variation in C/N ratio, presence of some sugars, besides several other physical factors are important in the development of fermentation process. Proteases of fungal origin can be produced cost effectively, have an advantage faster production, the ease with which the enzymes can be modified and mycelium can be easily removed by filtration. The production of proteases has been carried out using submerged fermentation, but conditions in solid state fermentation lead to several potential advantages for the production of fungal enzymes. This review focuses on the production of fungal proteases, their distribution, structural-functional aspects, physical and chemical parameters, and the use of these enzymes in industrial applications.

  7. Natural inhibitors of tumor-associated proteases

    International Nuclear Information System (INIS)

    Magdolen, U.; Krol, J.; Sato, S.; Schmitt, M.; Magdolen, V.; Krueger, A.; Mueller, M.M.; Sperl, S.

    2002-01-01

    The turnover and remodelling of extracellular matrix (ECM) is an essential part of many normal biological processes including development, morphogenesis, and wound healing. ECM turnover also occurs in severe pathological situations like artherosclerosis, fibrosis, tumor invasion and metastasis. The major proteases involved in this turnover are serine proteases (especially the urokinase-type plasminogen activator/plasmin system), matrix metalloproteases (a family of about 20 zinc-dependent endopeptidases including collagenases, gelatinases, stromelysins, and membrane-type metalloproteases), and cysteine proteases. In vivo, the activity of these proteases is tightly regulated in the extracellular space by zymogen activation and/or controlled inhibition. In the present review, we give an overview on the structure and biochemical properties of important tumor-associated protease inhibitors such as plasminogen activator inhibitor type 1 and type 2 (PAI-1, PAI-2), tissue inhibitors of metalloproteinases (TIMP-1, -2, -3, and -4), and the cysteine protease inhibitor cystatin C. Interestingly, some of these inhibitors of tumor-associated proteases display multiple functions which rather promote than inhibit tumor progression, when the presence of inhibitors in the tumor tissue is not balanced. (author)

  8. Extracellular proteases of Trichoderma species. A review.

    Science.gov (United States)

    Kredics, L; Antal, Zsuzsanna; Szekeres, A; Hatvani, L; Manczinger, L; Vágvölgyi, Cs; Nagy, Erzsébet

    2005-01-01

    Cellulolytic, xylanolytic, chitinolytic and beta-1,3-glucanolytic enzyme systems of species belonging to the filamentous fungal genus Trichoderma have been investigated in details and are well characterised. The ability of Trichoderma strains to produce extracellular proteases has also been known for a long time, however, the proteolytic enzyme system is relatively unknown in this genus. Fortunately, in the recent years more and more attention is focused on the research in this field. The role of Trichoderma proteases in the biological control of plant pathogenic fungi and nematodes has been demonstrated, and it is also suspected that they may be important for the competitive saprophytic ability of green mould isolates and may represent potential virulence factors of Trichoderma strains as emerging fungal pathogens of clinical importance. The aim of this review is to summarize the information available about the extracellular proteases of Trichoderma. Numerous studies are available about the extracellular proteolytic enzyme profiles of Trichoderma strains and about the effect of abiotic environmental factors on protease activities. A number of protease enzymes have been purified to homogeneity and some protease encoding genes have been cloned and characterized. These results will be reviewed and the role of Trichoderma proteases in biological control as well as their advantages and disadvantages in biotechnology will be discussed.

  9. Gut proteases target Yersinia invasin in vivo

    Directory of Open Access Journals (Sweden)

    Freund Sandra

    2011-04-01

    Full Text Available Abstract Background Yersinia enterocolitica is a common cause of food borne gastrointestinal disease. After oral uptake, yersiniae invade Peyer's patches of the distal ileum. This is accomplished by the binding of the Yersinia invasin to β1 integrins on the apical surface of M cells which overlie follicle associated lymphoid tissue. The gut represents a barrier that severely limits yersiniae from reaching deeper tissues such as Peyer's patches. We wondered if gut protease attack on invasion factors could contribute to the low number of yersiniae invading Peyer's patches. Findings Here we show that invasin is rapidly degraded in vivo by gut proteases in the mouse infection model. In vivo proteolytic degradation is due to proteolysis by several gut proteases such as trypsin, α-chymotrypsin, pancreatic elastase, and pepsin. Protease treated yersiniae are shown to be less invasive in a cell culture model. YadA, another surface adhesin is cleaved by similar concentrations of gut proteases but Myf was not cleaved, showing that not all surface proteins are equally susceptible to degradation by gut proteases. Conclusions We demonstrate that gut proteases target important Yersinia virulence factors such as invasin and YadA in vivo. Since invasin is completely degraded within 2-3 h after reaching the small intestine of mice, it is no longer available to mediate invasion of Peyer's patches.

  10. High-Resolution Analysis of Coronavirus Gene Expression by RNA Sequencing and Ribosome Profiling.

    Science.gov (United States)

    Irigoyen, Nerea; Firth, Andrew E; Jones, Joshua D; Chung, Betty Y-W; Siddell, Stuart G; Brierley, Ian

    2016-02-01

    Members of the family Coronaviridae have the largest genomes of all RNA viruses, typically in the region of 30 kilobases. Several coronaviruses, such as Severe acute respiratory syndrome-related coronavirus (SARS-CoV) and Middle East respiratory syndrome-related coronavirus (MERS-CoV), are of medical importance, with high mortality rates and, in the case of SARS-CoV, significant pandemic potential. Other coronaviruses, such as Porcine epidemic diarrhea virus and Avian coronavirus, are important livestock pathogens. Ribosome profiling is a technique which exploits the capacity of the translating ribosome to protect around 30 nucleotides of mRNA from ribonuclease digestion. Ribosome-protected mRNA fragments are purified, subjected to deep sequencing and mapped back to the transcriptome to give a global "snap-shot" of translation. Parallel RNA sequencing allows normalization by transcript abundance. Here we apply ribosome profiling to cells infected with Murine coronavirus, mouse hepatitis virus, strain A59 (MHV-A59), a model coronavirus in the same genus as SARS-CoV and MERS-CoV. The data obtained allowed us to study the kinetics of virus transcription and translation with exquisite precision. We studied the timecourse of positive and negative-sense genomic and subgenomic viral RNA production and the relative translation efficiencies of the different virus ORFs. Virus mRNAs were not found to be translated more efficiently than host mRNAs; rather, virus translation dominates host translation at later time points due to high levels of virus transcripts. Triplet phasing of the profiling data allowed precise determination of translated reading frames and revealed several translated short open reading frames upstream of, or embedded within, known virus protein-coding regions. Ribosome pause sites were identified in the virus replicase polyprotein pp1a ORF and investigated experimentally. Contrary to expectations, ribosomes were not found to pause at the ribosomal

  11. High-Resolution Analysis of Coronavirus Gene Expression by RNA Sequencing and Ribosome Profiling.

    Directory of Open Access Journals (Sweden)

    Nerea Irigoyen

    2016-02-01

    Full Text Available Members of the family Coronaviridae have the largest genomes of all RNA viruses, typically in the region of 30 kilobases. Several coronaviruses, such as Severe acute respiratory syndrome-related coronavirus (SARS-CoV and Middle East respiratory syndrome-related coronavirus (MERS-CoV, are of medical importance, with high mortality rates and, in the case of SARS-CoV, significant pandemic potential. Other coronaviruses, such as Porcine epidemic diarrhea virus and Avian coronavirus, are important livestock pathogens. Ribosome profiling is a technique which exploits the capacity of the translating ribosome to protect around 30 nucleotides of mRNA from ribonuclease digestion. Ribosome-protected mRNA fragments are purified, subjected to deep sequencing and mapped back to the transcriptome to give a global "snap-shot" of translation. Parallel RNA sequencing allows normalization by transcript abundance. Here we apply ribosome profiling to cells infected with Murine coronavirus, mouse hepatitis virus, strain A59 (MHV-A59, a model coronavirus in the same genus as SARS-CoV and MERS-CoV. The data obtained allowed us to study the kinetics of virus transcription and translation with exquisite precision. We studied the timecourse of positive and negative-sense genomic and subgenomic viral RNA production and the relative translation efficiencies of the different virus ORFs. Virus mRNAs were not found to be translated more efficiently than host mRNAs; rather, virus translation dominates host translation at later time points due to high levels of virus transcripts. Triplet phasing of the profiling data allowed precise determination of translated reading frames and revealed several translated short open reading frames upstream of, or embedded within, known virus protein-coding regions. Ribosome pause sites were identified in the virus replicase polyprotein pp1a ORF and investigated experimentally. Contrary to expectations, ribosomes were not found to pause at the

  12. Papain-like protease (PLpro) inhibitory effects of cinnamic amides from Tribulus terrestris fruits.

    Science.gov (United States)

    Song, Yeong Hun; Kim, Dae Wook; Curtis-Long, Marcus John; Yuk, Heung Joo; Wang, Yan; Zhuang, Ningning; Lee, Kon Ho; Jeon, Kwon Seok; Park, Ki Hun

    2014-01-01

    Tribulus terrestris fruits are well known for their usage in pharmaceutical preparations and food supplements. The methanol extract of T. terrestris fruits showed potent inhibition against the papain-like protease (PLpro), an essential proteolylic enzyme for protection to pathogenic virus and bacteria. Subsequent bioactivity-guided fractionation of this extract led to six cinnamic amides (1-6) and ferulic acid (7). Compound 6 emerged as new compound possessing the very rare carbinolamide motif. These compounds (1-7) were evaluated for severe acute respiratory syndrome coronavirus (SARS-CoV) PLpro inhibitory activity to identify their potencies and kinetic behavior. Compounds (1-6) displayed significant inhibitory activity with IC50 values in the range 15.8-70.1 µM. The new cinnamic amide 6 was found to be most potent inhibitor with an IC50 of 15.8 µM. In kinetic studies, all inhibitors exhibited mixed type inhibition. Furthermore, the most active PLpro inhibitors (1-6) were proven to be present in the native fruits in high quantities by HPLC chromatogram and liquid chromatography with diode array detection and electrospray ionization mass spectrometry (LC-DAD-ESI/MS).

  13. Protease and protease inhibitory activity in pregnant and postpartum involuting uterus

    International Nuclear Information System (INIS)

    Milwidsky, A.; Beller, U.; Palti, Z.; Mayer, M.

    1982-01-01

    The presence of two distinct proteolytic activities in the rat uterus was confirmed with 14 C-labeled globin used as a sensitive protein substrate and following release of label into the trichloroacetic acid-soluble supernatant fraction. Protease I is a cytoplasmic acid protease while protease II is associated with the pellet fraction, can be extracted by 0.6 M sodium chloride, and is active at pH 7.0. Protease I activity is low during pregnancy and markedly increases at term achieving maximal activity at day 3 post partum with a subsequent decline to preterm activity values. Lactation did not affect the uterine protease I activity. Protease II activity is not significantly different during pregnancy, at term, and post partum. The presence of an inhibitor of protease I was suggested by a decrease in enzyme activity with an increased cytosolic protein concentration. The inhibitor also lessened bovine trypsin activity but had no effect on protease II. Although its inhibitory potency on trypsin fluctuated during the various uterine physiologic stages, these changes appeared to be statistically insignificant. Human uterine samples were also found to contain the two protease activities with similar changes in protease I post partum. It is suggested that, both in the rat and in man, uterine involution post partum is associated with a marked increase in activity of acid cytosolic protease, while a particulate neutral protease and a soluble inhibitor of trypsin, which are also present in uterine cells, do not appear to play a significant role in the dissolution of uterine tissues after parturition

  14. Aspartic Protease Zymography Case Study: Detection of Fungal Acid Proteases by Zymography.

    Science.gov (United States)

    Kernaghan, Gavin; Mayerhofer, Michael

    2017-01-01

    This chapter describes a method for the production and characterization of fungal acid proteases. Protease production is induced by growth on BSA media over a pH gradient and protein levels are monitored over time with the Bradford assay. Once protein is depleted, the media is purified and proteases are characterized by gelatin zymography using acrylamide and buffers at near-neutral pH. Maintaining pH levels below those found in traditional zymographic systems avoids the potential loss of activity that may occur in aspartic proteases under alkaline conditions.

  15. Activation of ADAM 12 protease by copper

    DEFF Research Database (Denmark)

    Loechel, F; Wewer, Ulla M.

    2001-01-01

    Conversion of latent proteases to the active form occurs by various mechanisms characteristic for different protease families. Here we report that the disintegrin metalloprotease ADAM 12-S is activated by Cu(II). Copper activation is distinct from the cysteine switch component of latency: elimina......Conversion of latent proteases to the active form occurs by various mechanisms characteristic for different protease families. Here we report that the disintegrin metalloprotease ADAM 12-S is activated by Cu(II). Copper activation is distinct from the cysteine switch component of latency......: elimination of the ADAM 12 cysteine switch by a point mutation in the propeptide had no effect on copper activation, whereas mutation of an unpaired cysteine residue in the catalytic domain resulted in a mutant form of ADAM 12-S that was insensitive to copper. This suggests a multi-step activation mechanism...... for ADAM 12 involving both furin cleavage and copper binding....

  16. Optimization of medium composition for thermostable protease ...

    African Journals Online (AJOL)

    SERVER

    2008-04-17

    Apr 17, 2008 ... Optimization of the fermentation medium for maximization of thermostable neutral protease production by Bacillus sp. ..... Each contour curve represented an infinite number of combinations of two ..... Production in sea-water of.

  17. Partial Purification and Characterization of Extracellular Protease ...

    African Journals Online (AJOL)

    USER

    Keywords: Protease, lactic acid bacteria, Pediococcus acidilactici, enzyme ... confers organoleptic improvements in fermented foods ... was characterized by studying the effect of substrate ... addition of solid ammonium sulphate up to 80%.

  18. First full length sequences of the S gene of European isolates reveal further diversity among turkey coronaviruses.

    OpenAIRE

    2011-01-01

    Abstract An increasing incidence of enteric disorders clinically evocative of the poult enteritis complex has been observed in turkeys in France since 2003. Using a newly designed real-time RT-PCR assay specific for the nucleocapsid (N) gene of infectious bronchitis virus (IBV) and turkey coronaviruses (TCoV), coronaviruses were identified in 37 % of the intestinal samples collected from diseased turkey flocks. The full length Spike (S) gene of these viruses was amplified, cloned a...

  19. Molecular interaction study of commercial cyclic peptides and MERS-COV papain-like protease as novel drug candidate for MERS-COV

    Science.gov (United States)

    Nasution, M. A. F.; Azzuhdi, M. G.; Tambunan, U. S. F.

    2017-07-01

    Middle-east respiratory syndrome coronavirus (MERS-CoV) has become the current outbreak, MERS-CoV infection results in illness at the respiratory system, digestive, and even lead to death with an average mortality caused by MERS-CoV infection reaches 50 %. Until now, there is not any effective vaccine or drug to ward off MERS-CoV infection. Papain-like protease (PLpro) is responsible for cleavage of a nonstructural protein that is essential for viral maturation. Inhibition of PLpro with a ligand will block the cleavage process of nonstructural protein, thus reduce the infection of MERS-CoV. Through of bioinformatics study with molecular docking and binding interaction analysis of commercial cyclic peptides, aldosterone secretion inhibiting factor (1-35) (bovine) was obtained as an inhibitor for PLpro. Thus, aldosterone secretion inhibiting factor (1-35) (bovine) has a potential as a novel candidate drug for treating MERS-CoV.

  20. Purification and characterization of protease enzyme from ...

    African Journals Online (AJOL)

    The enzyme was active in pH range 5 to11 and temperature of 30 to 80°C. The optimum pH and the temperature for protease activity were recorded to be pH 8 and 50°C, respectively. The enzyme was stable up to 40°C and pH 9. The protease activity was inhibited by Zn2+, Ni2+ and Sn2+ and increased by Ca2+, Mg2+ ...

  1. Coronavirus gene 7 counteracts host defenses and modulates virus virulence.

    Directory of Open Access Journals (Sweden)

    Jazmina L G Cruz

    2011-06-01

    Full Text Available Transmissible gastroenteritis virus (TGEV genome contains three accessory genes: 3a, 3b and 7. Gene 7 is only present in members of coronavirus genus a1, and encodes a hydrophobic protein of 78 aa. To study gene 7 function, a recombinant TGEV virus lacking gene 7 was engineered (rTGEV-Δ7. Both the mutant and the parental (rTGEV-wt viruses showed the same growth and viral RNA accumulation kinetics in tissue cultures. Nevertheless, cells infected with rTGEV-Δ7 virus showed an increased cytopathic effect caused by an enhanced apoptosis mediated by caspase activation. Macromolecular synthesis analysis showed that rTGEV-Δ7 virus infection led to host translational shut-off and increased cellular RNA degradation compared with rTGEV-wt infection. An increase of eukaryotic translation initiation factor 2 (eIF2α phosphorylation and an enhanced nuclease, most likely RNase L, activity were observed in rTGEV-Δ7 virus infected cells. These results suggested that the removal of gene 7 promoted an intensified dsRNA-activated host antiviral response. In protein 7 a conserved sequence motif that potentially mediates binding to protein phosphatase 1 catalytic subunit (PP1c, a key regulator of the cell antiviral defenses, was identified. We postulated that TGEV protein 7 may counteract host antiviral response by its association with PP1c. In fact, pull-down assays demonstrated the interaction between TGEV protein 7, but not a protein 7 mutant lacking PP1c binding motif, with PP1. Moreover, the interaction between protein 7 and PP1 was required, during the infection, for eIF2α dephosphorylation and inhibition of cell RNA degradation. Inoculation of newborn piglets with rTGEV-Δ7 and rTGEV-wt viruses showed that rTGEV-Δ7 virus presented accelerated growth kinetics and pathology compared with the parental virus. Overall, the results indicated that gene 7 counteracted host cell defenses, and modified TGEV persistence increasing TGEV survival. Therefore, the

  2. Carbohydrate protease conjugates: Stabilized proteases for peptide synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Wartchow, C.A.; Wang, Peng; Bednarski, M.D.; Callstrom, M.R. [Ohio State Univ., Columbus, OH (United States)]|[Lawrence Berkeley Lab., CA (United States)

    1995-12-31

    The synthesis of oligopeptides using stable carbohydrate protease conjugates (CPCs) was examined in acetonitrile solvent systems. CPC[{alpha}-chymotrypsin] was used for the preparation of peptides containing histidine, phenylalanine, tryptophan in the P{sub 1} position in 60-93% yield. The CPC[{alpha}-chymotrypsin]-catalyzed synthesis of octamer Z-Gly-Gly-Phe-Gly-Gly-Phe-Gly-Gly-OEt from Z-Gly-Gly-Phe-Gly-Gly-Phe-OMe was achieved in 71% yield demonstrating that synthesis peptides containing both hydrophylic and hydrophobic amino acids. The P{sub 2} specificity of papain for aromatic residues was utilized for the 2 + 3 coupling of Z-Tyr-Gly-OMe to H{sub 2}N-Gly-Phe-Leu-OH to generate the leucine enkephalin derivative in 79% yield. Although papain is nonspecific for the hydrolysis of N-benzyloxycarbonyl amino acid methyl esters in aqueous solution, the rates of synthesis for these derivitives with nucleophile leucine tert-butyl ester differed by nearly 2 orders of magnitude. CPC[thermolysin] was used to prepare the aspartame precursor Z-Asp-Phe-OMe in 90% yield. The increased stability of CPCs prepared from periodate-modified poly(2-methacryl- amido-2-deoxy-D-glucose), poly(2-methacrylamido-2-deoxy-D-galactose), and poly(5-methacryl-amido-5-deoxy-D-ribose), carbohydrate materials designed to increase the aldehyde concentration in aqueous solution, suggests that the stability of CPCs is directly related to the aldehyde concentration of the carbohydrate material. Periodate oxidation of poly(2-methacrylamido-2-deoxy-D-glucose) followed by covalent attachment to {alpha}-chymotrypsin gave a CPC with catalytic activity in potassium phosphate buffer at 90{degrees}C for 2 h. 1 fig., 1 tab., 40 refs.

  3. Isolation and characterization of a bat SARS-like coronavirus that uses the ACE2 receptor.

    Science.gov (United States)

    Ge, Xing-Yi; Li, Jia-Lu; Yang, Xing-Lou; Chmura, Aleksei A; Zhu, Guangjian; Epstein, Jonathan H; Mazet, Jonna K; Hu, Ben; Zhang, Wei; Peng, Cheng; Zhang, Yu-Ji; Luo, Chu-Ming; Tan, Bing; Wang, Ning; Zhu, Yan; Crameri, Gary; Zhang, Shu-Yi; Wang, Lin-Fa; Daszak, Peter; Shi, Zheng-Li

    2013-11-28

    The 2002-3 pandemic caused by severe acute respiratory syndrome coronavirus (SARS-CoV) was one of the most significant public health events in recent history. An ongoing outbreak of Middle East respiratory syndrome coronavirus suggests that this group of viruses remains a key threat and that their distribution is wider than previously recognized. Although bats have been suggested to be the natural reservoirs of both viruses, attempts to isolate the progenitor virus of SARS-CoV from bats have been unsuccessful. Diverse SARS-like coronaviruses (SL-CoVs) have now been reported from bats in China, Europe and Africa, but none is considered a direct progenitor of SARS-CoV because of their phylogenetic disparity from this virus and the inability of their spike proteins to use the SARS-CoV cellular receptor molecule, the human angiotensin converting enzyme II (ACE2). Here we report whole-genome sequences of two novel bat coronaviruses from Chinese horseshoe bats (family: Rhinolophidae) in Yunnan, China: RsSHC014 and Rs3367. These viruses are far more closely related to SARS-CoV than any previously identified bat coronaviruses, particularly in the receptor binding domain of the spike protein. Most importantly, we report the first recorded isolation of a live SL-CoV (bat SL-CoV-WIV1) from bat faecal samples in Vero E6 cells, which has typical coronavirus morphology, 99.9% sequence identity to Rs3367 and uses ACE2 from humans, civets and Chinese horseshoe bats for cell entry. Preliminary in vitro testing indicates that WIV1 also has a broad species tropism. Our results provide the strongest evidence to date that Chinese horseshoe bats are natural reservoirs of SARS-CoV, and that intermediate hosts may not be necessary for direct human infection by some bat SL-CoVs. They also highlight the importance of pathogen-discovery programs targeting high-risk wildlife groups in emerging disease hotspots as a strategy for pandemic preparedness.

  4. Human Coronaviruses: Insights into Environmental Resistance and Its Influence on the Development of New Antiseptic Strategies

    Science.gov (United States)

    Geller, Chloé; Varbanov, Mihayl; Duval, Raphaël E.

    2012-01-01

    The Coronaviridae family, an enveloped RNA virus family, and, more particularly, human coronaviruses (HCoV), were historically known to be responsible for a large portion of common colds and other upper respiratory tract infections. HCoV are now known to be involved in more serious respiratory diseases, i.e. bronchitis, bronchiolitis or pneumonia, especially in young children and neonates, elderly people and immunosuppressed patients. They have also been involved in nosocomial viral infections. In 2002–2003, the outbreak of severe acute respiratory syndrome (SARS), due to a newly discovered coronavirus, the SARS-associated coronavirus (SARS-CoV); led to a new awareness of the medical importance of the Coronaviridae family. This pathogen, responsible for an emerging disease in humans, with high risk of fatal outcome; underline the pressing need for new approaches to the management of the infection, and primarily to its prevention. Another interesting feature of coronaviruses is their potential environmental resistance, despite the accepted fragility of enveloped viruses. Indeed, several studies have described the ability of HCoVs (i.e. HCoV 229E, HCoV OC43 (also known as betacoronavirus 1), NL63, HKU1 or SARS-CoV) to survive in different environmental conditions (e.g. temperature and humidity), on different supports found in hospital settings such as aluminum, sterile sponges or latex surgical gloves or in biological fluids. Finally, taking into account the persisting lack of specific antiviral treatments (there is, in fact, no specific treatment available to fight coronaviruses infections), the Coronaviridae specificities (i.e. pathogenicity, potential environmental resistance) make them a challenging model for the development of efficient means of prevention, as an adapted antisepsis-disinfection, to prevent the environmental spread of such infective agents. This review will summarize current knowledge on the capacity of human coronaviruses to survive in the

  5. Escherichia coli contains a soluble ATP-dependent protease (Ti) distinct from protease La

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, B.J.; Park, W.J.; Chung, C.H.; Goldberg, A.L.

    1987-08-01

    The energy requirement for protein breakdown in Escherichia coli has generally been attributed to the ATP-dependence of protease La, the lon gene product. The authors have partially purified another ATP-dependent protease from lon/sup -/ cells that lack protease La (as shown by immunoblotting). This enzyme hydrolyzes (/sup 3/H)methyl-casein to acid-soluble products in the presence of ATP and Mg/sup 2 +/. ATP hydrolysis appears necessary for proteolytic activity. Since this enzyme is inhibited by diisopropyl fluorophosphate, it appears to be a serine protease, but it also contains essential thiol residues. They propose to name this enzyme protease Ti. It differs from protease La in nucleotide specificity, inhibitor sensitivity, and subunit composition. On gel filtration, protease Ti has an apparent molecular weight of 370,000. It can be fractionated by phosphocellulose chromatography or by DEAE chromatography into two components with apparent molecular weights of 260,000 and 140,000. When separated, they do not show preteolytic activity. One of these components, by itself, has ATPase activity and is labile in the absence of ATP. The other contains the diisopropyl fluorophosphate-sensitive proteolytic site. These results and the similar findings of Katayama-Fujimura et al. indicate that E. coli contains two ATP-hydrolyzing proteases, which differ in many biochemical features and probably in their physiological roles.

  6. Escherichia coli contains a soluble ATP-dependent protease (Ti) distinct from protease La

    International Nuclear Information System (INIS)

    Hwang, B.J.; Park, W.J.; Chung, C.H.; Goldberg, A.L.

    1987-01-01

    The energy requirement for protein breakdown in Escherichia coli has generally been attributed to the ATP-dependence of protease La, the lon gene product. The authors have partially purified another ATP-dependent protease from lon - cells that lack protease La (as shown by immunoblotting). This enzyme hydrolyzes [ 3 H]methyl-casein to acid-soluble products in the presence of ATP and Mg 2+ . ATP hydrolysis appears necessary for proteolytic activity. Since this enzyme is inhibited by diisopropyl fluorophosphate, it appears to be a serine protease, but it also contains essential thiol residues. They propose to name this enzyme protease Ti. It differs from protease La in nucleotide specificity, inhibitor sensitivity, and subunit composition. On gel filtration, protease Ti has an apparent molecular weight of 370,000. It can be fractionated by phosphocellulose chromatography or by DEAE chromatography into two components with apparent molecular weights of 260,000 and 140,000. When separated, they do not show preteolytic activity. One of these components, by itself, has ATPase activity and is labile in the absence of ATP. The other contains the diisopropyl fluorophosphate-sensitive proteolytic site. These results and the similar findings of Katayama-Fujimura et al. indicate that E. coli contains two ATP-hydrolyzing proteases, which differ in many biochemical features and probably in their physiological roles

  7. Three monoclonal antibodies against the serpin protease nexin-1 prevent protease translocation

    DEFF Research Database (Denmark)

    Kousted, Tina Mostrup; Skjoedt, K; Petersen, S V

    2013-01-01

    abolish the protease inhibitory activity of PN-1. In the presence of the antibodies, PN-1 does not form a complex with its target proteases, but is recovered in a reactive centre cleaved form. Using site-directed mutagenesis, we mapped the three overlapping epitopes to an area spanning the gap between...

  8. Purification and characterisation of a protease (tamarillin) from tamarillo fruit

    KAUST Repository

    Li, Zhao

    2018-02-16

    A protease from tamarillo fruit (Cyphomandra betacea Cav.) was purified by ammonium sulphate precipitation and diethylaminoethyl-Sepharose chromatography. Protease activity was determined on selected peak fractions using a casein substrate. Sodium dodecyl sulphate polyacrylamide gel electrophoresis analysis showed that the peak with the highest protease activity consisted of one protein of molecular mass ca. 70 kDa. The protease showed optimal activity at pH 11 and 60°C. It was sensitive to phenylmethylsulphonyl fluoride while ethylenediaminetetraacetic acid and p-chloromercuribenzoic acid had little effect on its activity, indicating that this enzyme was a serine protease. Hg2+ strongly inhibited enzyme activity, possibly due to formation of mercaptide bonds with the thiol groups of the protease, suggesting that some cysteine residues may be located close to the active site. De novo sequencing strongly indicated that the protease was a subtilisin-like alkaline serine protease. The protease from tamarillo has been named \\'tamarillin\\'.

  9. Purification and characterisation of a protease (tamarillin) from tamarillo fruit

    KAUST Repository

    Li, Zhao; Scott, Ken; Hemar, Yacine; Zhang, Huoming; Otter, Don

    2018-01-01

    A protease from tamarillo fruit (Cyphomandra betacea Cav.) was purified by ammonium sulphate precipitation and diethylaminoethyl-Sepharose chromatography. Protease activity was determined on selected peak fractions using a casein substrate. Sodium dodecyl sulphate polyacrylamide gel electrophoresis analysis showed that the peak with the highest protease activity consisted of one protein of molecular mass ca. 70 kDa. The protease showed optimal activity at pH 11 and 60°C. It was sensitive to phenylmethylsulphonyl fluoride while ethylenediaminetetraacetic acid and p-chloromercuribenzoic acid had little effect on its activity, indicating that this enzyme was a serine protease. Hg2+ strongly inhibited enzyme activity, possibly due to formation of mercaptide bonds with the thiol groups of the protease, suggesting that some cysteine residues may be located close to the active site. De novo sequencing strongly indicated that the protease was a subtilisin-like alkaline serine protease. The protease from tamarillo has been named 'tamarillin'.

  10. The dimer interfaces of protease and extra-protease domains influence the activation of protease and the specificity of GagPol cleavage.

    Science.gov (United States)

    Pettit, Steven C; Gulnik, Sergei; Everitt, Lori; Kaplan, Andrew H

    2003-01-01

    Activation of the human immunodeficiency virus type 1 (HIV-1) protease is an essential step in viral replication. As is the case for all retroviral proteases, enzyme activation requires the formation of protease homodimers. However, little is known about the mechanisms by which retroviral proteases become active within their precursors. Using an in vitro expression system, we have examined the determinants of activation efficiency and the order of cleavage site processing for the protease of HIV-1 within the full-length GagPol precursor. Following activation, initial cleavage occurs between the viral p2 and nucleocapsid proteins. This is followed by cleavage of a novel site located in the transframe domain. Mutational analysis of the dimer interface of the protease produced differential effects on activation and specificity. A subset of mutations produced enhanced cleavage at the amino terminus of the protease, suggesting that, in the wild-type precursor, cleavages that liberate the protease are a relatively late event. Replacement of the proline residue at position 1 of the protease dimer interface resulted in altered cleavage of distal sites and suggests that this residue functions as a cis-directed specificity determinant. In summary, our studies indicate that interactions within the protease dimer interface help determine the order of precursor cleavage and contribute to the formation of extended-protease intermediates. Assembly domains within GagPol outside the protease domain also influence enzyme activation.

  11. E3 protein of bovine coronavirus is a receptor-destroying enzyme with acetylesterase activity

    International Nuclear Information System (INIS)

    Vlasak, R.; Luytjes, W.; Leider, J.; Spaan, W.; Palese, P.

    1988-01-01

    In addition to members of the Orthomyxoviridae and Paramyxoviridae, several coronaviruses have been shown to possess receptor-destroying activities. Purified bovine coronavirus (BCV) preparations have an esterase activity which inactivates O-acetylsialic acid-containing receptors on erythrocytes. Diisopropyl fluorophosphate (DFP) completely inhibits this receptor-destroying activity of BCV, suggesting that the viral enzyme is a serine esterase. Treatment of purified BCV with [ 3 H]DFP and subsequent sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the proteins revealed that the esterase/receptor-destroying activity of BCV is associated with the E3 protein was specifically phosphorylated. This finding suggests that the esterase/receptor-destroying activity of BCV is associated with the E3 protein. Furthermore, treatment of BCV with DFP dramatically reduced its infectivity in a plaque assay. It is assumed that the esterase activity of BCV is required in an early step of virus replication, possible during virus entry or uncoating

  12. The Middle East respiratory syndrome coronavirus (MERS-CoV does not replicate in Syrian hamsters.

    Directory of Open Access Journals (Sweden)

    Emmie de Wit

    Full Text Available In 2012 a novel coronavirus, MERS-CoV, associated with severe respiratory disease emerged in the Arabian Peninsula. To date, 55 human cases have been reported, including 31 fatal cases. Several of the cases were likely a result of human-to-human transmission. The emergence of this novel coronavirus prompts the need for a small animal model to study the pathogenesis of this virus and to test the efficacy of potential intervention strategies. In this study we explored the use of Syrian hamsters as a small animal disease model, using intratracheal inoculation and inoculation via aerosol. Clinical signs of disease, virus replication, histological lesions, cytokine upregulation nor seroconversion were observed in any of the inoculated animals, indicating that MERS-CoV does not replicate in Syrian hamsters.

  13. E3 protein of bovine coronavirus is a receptor-destroying enzyme with acetylesterase activity

    Energy Technology Data Exchange (ETDEWEB)

    Vlasak, R.; Luytjes, W.; Leider, J.; Spaan, W.; Palese, P.

    1988-12-01

    In addition to members of the Orthomyxoviridae and Paramyxoviridae, several coronaviruses have been shown to possess receptor-destroying activities. Purified bovine coronavirus (BCV) preparations have an esterase activity which inactivates O-acetylsialic acid-containing receptors on erythrocytes. Diisopropyl fluorophosphate (DFP) completely inhibits this receptor-destroying activity of BCV, suggesting that the viral enzyme is a serine esterase. Treatment of purified BCV with (/sup 3/H)DFP and subsequent sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the proteins revealed that the esterase/receptor-destroying activity of BCV is associated with the E3 protein was specifically phosphorylated. This finding suggests that the esterase/receptor-destroying activity of BCV is associated with the E3 protein. Furthermore, treatment of BCV with DFP dramatically reduced its infectivity in a plaque assay. It is assumed that the esterase activity of BCV is required in an early step of virus replication, possible during virus entry or uncoating.

  14. Factors Influencing Emergency Nurses' Burnout During an Outbreak of Middle East Respiratory Syndrome Coronavirus in Korea

    OpenAIRE

    Kim, Ji Soo; Choi, Jeong Sil

    2016-01-01

    Purpose: Emergency department (ED) nurses suffer from persistent stress after experiencing the traumatic event of exposure to Middle East respiratory syndrome coronavirus (MERS-CoV), which can subsequently lead to burnout. This study aimed to assess ED nurses' burnout level during an outbreak of MERS-CoV and to identify influencing factors in order to provide basic information for lowering and preventing the level of burnout. Methods: Study participants were ED nurses working in eight hosp...

  15. Lithium chloride inhibits the coronavirus infectious bronchitis virus in cell culture.

    OpenAIRE

    Harrison , Sally; Tarpey , Ian; Rothwell , Lisa; Kasier , Pete; Hiscox , Julian

    2007-01-01

    Abstract The avian coronavirus infectious bronchitis virus (IBV) is a major economic pathogen of domestic poultry which, despite vaccination, causes mortality and significant losses in production. During replication of the RNA genome there is a high frequency of mutation and recombination which has given rise to many strains of IBV and results in the potential for new and emerging strains. Currently the live-attenuated vaccine gives poor cross strain immunity. Effective antivira...

  16. Discovery of a novel canine respiratory coronavirus support genetic recombination among betacoronavirus1.

    Science.gov (United States)

    Lu, Shuai; Wang, Yanqun; Chen, Yingzhu; Wu, Bingjie; Qin, Kun; Zhao, Jincun; Lou, Yongliang; Tan, Wenjie

    2017-06-02

    Although canine respiratory coronavirus (CRCoV) is an important respiratory pathogen that is prevalent in many countries, only one complete genome sequence of CRCoV (South Korea strain K37) has been obtained to date. Genome-wide analyses and recombination have rarely been conducted, as small numbers of samples and limited genomic characterization have previously prevented further analyses. Herein, we report a unique CRCoV strain, denoted strain BJ232, derived from a CRCoV-positive dog with a mild respiratory infection. Phylogenetic analysis based on complete genome of all available coronaviruses consistently show that CRCoV BJ232 is most closely related to human coronavirus OC43 (HCoV-OC43) and BCoV, forming a separate clade that split off early from other Betacoronavirus 1. Based on the phylogenetic and SimPlot analysis we propose that CRCoV-K37 was derived from genetic recombination between CRCoV-BJ232 and BCoV. In detail, spike (S) gene of CRCoV-K37 clustered with CRCoV-BJ232. However orf1ab, membrane (M) and nucleocapsid (N) genes were more related to Bovine coronavirus (BCoV) than CRCoV-B232. Molecular epidemic analysis confirmed the prevalence of CRCoV-BJ232 lineage around the world for a long time. Recombinant events among Betacoronavirus 1 may have implications for CRCoV transmissibility. All these findings provide further information regarding the origin of CRCoV. Copyright © 2017. Published by Elsevier B.V.

  17. Genome-wide analysis of codon usage bias in Bovine Coronavirus

    OpenAIRE

    Castells, Mat?as; Victoria, Mat?as; Colina, Rodney; Musto, H?ctor; Cristina, Juan

    2017-01-01

    Background Bovine coronavirus (BCoV) belong to the genus Betacoronavirus of the family Coronaviridae. BCoV are widespread around the world and cause enteric or respiratory infections among cattle, leading to important economic losses to the beef and dairy industry worldwide. To study the relation of codon usage among viruses and their hosts is essential to understand host-pathogen interaction, evasion from host?s immune system and evolution. Methods We performed a comprehensive analysis of co...

  18. Inactivation of surrogate coronaviruses on hard surfaces by health care germicides.

    Science.gov (United States)

    Hulkower, Rachel L; Casanova, Lisa M; Rutala, William A; Weber, David J; Sobsey, Mark D

    2011-06-01

    In the 2003 severe acute respiratory syndrome outbreak, finding viral nucleic acids on hospital surfaces suggested surfaces could play a role in spread in health care environments. Surface disinfection may interrupt transmission, but few data exist on the effectiveness of health care germicides against coronaviruses on surfaces. The efficacy of health care germicides against 2 surrogate coronaviruses, mouse hepatitis virus (MHV) and transmissible gastroenteritis virus (TGEV), was tested using the quantitative carrier method on stainless steel surfaces. Germicides were o-phenylphenol/p-tertiary amylphenol) (a phenolic), 70% ethanol, 1:100 sodium hypochlorite, ortho-phthalaldehyde (OPA), instant hand sanitizer (62% ethanol), and hand sanitizing spray (71% ethanol). After 1-minute contact time, for TGEV, there was a log(10) reduction factor of 3.2 for 70% ethanol, 2.0 for phenolic, 2.3 for OPA, 0.35 for 1:100 hypochlorite, 4.0 for 62% ethanol, and 3.5 for 71% ethanol. For MHV, log(10) reduction factors were 3.9 for 70% ethanol, 1.3 for phenolic, 1.7 for OPA, 0.62 for 1:100 hypochlorite, 2.7 for 62% ethanol, and 2.0 for 71% ethanol. Only ethanol reduced infectivity of the 2 coronaviruses by >3-log(10) after 1 minute. Germicides must be chosen carefully to ensure they are effective against viruses such as severe acute respiratory syndrome coronavirus. Copyright © 2011 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

  19. Bovine coronavirus in naturally andexperimentally exposed calves; viralshedding and the potential for transmission

    OpenAIRE

    Oma, Veslemøy Sunniva; Tråven, Madeleine; Alenius, S.; Myrmel, Mette; Stokstad, Maria

    2016-01-01

    Background Bovine coronavirus (BCoV) is a widely distributed pathogen, causing disease and economic losses in the cattle industry worldwide. Prevention of virus spread is impeded by a lack of basic knowledge concerning viral shedding and transmission potential in individual animals. The aims of the study were to investigate the duration and quantity of BCoV shedding in feces and nasal secretions related to clinical signs, the presence of virus in blood and tissues and to test the hypothesis t...

  20. The role of viral population diversity in adaptation of bovine coronavirus to new host environments.

    Directory of Open Access Journals (Sweden)

    Monica K Borucki

    Full Text Available The high mutation rate of RNA viruses enables a diverse genetic population of viral genotypes to exist within a single infected host. In-host genetic diversity could better position the virus population to respond and adapt to a diverse array of selective pressures such as host-switching events. Multiple new coronaviruses, including SARS, have been identified in human samples just within the last ten years, demonstrating the potential of coronaviruses as emergent human pathogens. Deep sequencing was used to characterize genomic changes in coronavirus quasispecies during simulated host-switching. Three bovine nasal samples infected with bovine coronavirus were used to infect human and bovine macrophage and lung cell lines. The virus reproduced relatively well in macrophages, but the lung cell lines were not infected efficiently enough to allow passage of non lab-adapted samples. Approximately 12 kb of the genome was amplified before and after passage and sequenced at average coverages of nearly 950×(454 sequencing and 38,000×(Illumina. The consensus sequence of many of the passaged samples had a 12 nucleotide insert in the consensus sequence of the spike gene, and multiple point mutations were associated with the presence of the insert. Deep sequencing revealed that the insert was present but very rare in the unpassaged samples and could quickly shift to dominate the population when placed in a different environment. The insert coded for three arginine residues, occurred in a region associated with fusion entry into host cells, and may allow infection of new cell types via heparin sulfate binding. Analysis of the deep sequencing data indicated that two distinct genotypes circulated at different frequency levels in each sample, and support the hypothesis that the mutations present in passaged strains were "selected" from a pre-existing pool rather than through de novo mutation and subsequent population fixation.

  1. Genetic diversity of bats coronaviruses in the Atlantic Forest hotspot biome, Brazil.

    Science.gov (United States)

    Góes, Luiz Gustavo Bentim; Campos, Angélica Cristine de Almeida; Carvalho, Cristiano de; Ambar, Guilherme; Queiroz, Luzia Helena; Cruz-Neto, Ariovaldo Pereira; Munir, Muhammad; Durigon, Edison Luiz

    2016-10-01

    Bats are notorious reservoirs of genetically-diverse and high-profile pathogens, and are playing crucial roles in the emergence and re-emergence of viruses, both in human and in animals. In this report, we identified and characterized previously unknown and diverse genetic clusters of bat coronaviruses in the Atlantic Forest Biome, Brazil. These results highlight the virus richness of bats and their possible roles in the public health. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Association of seropositivity for influenza and coronaviruses with history of mood disorders and suicide attempts.

    Science.gov (United States)

    Okusaga, Olaoluwa; Yolken, Robert H; Langenberg, Patricia; Lapidus, Manana; Arling, Timothy A; Dickerson, Faith B; Scrandis, Debra A; Severance, Emily; Cabassa, Johanna A; Balis, Theodora; Postolache, Teodor T

    2011-04-01

    Anecdotal reports of mood disorder following infection with common respiratory viruses with neurotropic potential have been in existence since the last century. Nevertheless, systematic studies on the association between these viruses and mood disorders are lacking. Influenza A, B and coronavirus antibody titers were measured in 257 subjects with recurrent unipolar and bipolar disorder and healthy controls, by SCID. Pearson's χ² tests and logistic regression models were used to analyze associations between seropositivity for coronaviruses, influenza A and B viruses and the following: a) history of recurrent mood disorders b) having attempted suicide in the past c) uni- vs. bi-polarity and d) presence of psychotic symptoms during mood episodes. Seropositivity for influenza A (p=0.004), B (pmood disorders but not with the specific diagnosis of unipolar or bipolar depression. Seropositivity for influenza B was significantly associated with a history of suicide attempt (p=0.001) and history of psychotic symptoms (p=0.005). The design was cross-sectional. Socioeconomic factors, inflammatory markers, and axis II psychopathology were not assessed. The association of seropositivity for influenza and coronaviruses with a history of mood disorders, and influenza B with suicidal behavior require replication in larger longitudinal samples. The need for these studies is additionally supported by the high incidence of these viral infections, the high prevalence of mood disorders, and resilience of suicide epidemics. Copyright © 2010 Elsevier B.V. All rights reserved.

  3. Coronavirus in Pigs: Significance and Presentation of Swine Epidemic Diarrhea Virus (PEDV in Colombia

    Directory of Open Access Journals (Sweden)

    Ricardo Piñeros

    2015-05-01

    Full Text Available The article seeks to study general aspects of the main coronaviruses affecting pigs, their presentation in Colombia, and particular aspects of porcine epidemic diarrhea virus (PEDV, emerging in different countries and generating a great impact on the health and economy of the swine industry. The main coronaviruses affecting swine are porcine transmissible gastroenteritis virus (TGEV, porcine respiratory coronavirus (PRCV, porcine hemagglutinating encephalomyelitis virus (PHEV, PEDV, and porcine deltacoronavirus (PDCoV. Long ago in Colombia there had been reports of TGEV and PRCV associated with the importation of animals from the United States, which was controlled in the infected farms and in quarantine units. PEDV was first detected in Colombia in mid-March 2014; the Colombian Agricultural Institute issued a health alert in Neiva (Huila, Fusagasugá and Silvania (Cundinamarca, and Puerto López (Meta due to the unusual presentation of epidemic vomiting and diarrhea in young and adult animals, abortion in pregnant sows, with high mortality rates (up to 100% in animals during the first week of age. At present the disease has been reported in other municipalities of the country as well as in different countries with similar clinical conditions and mortality rates in pigs with high economic losses for the swine sector.

  4. Crystallization and diffraction analysis of the SARS coronavirus nsp10–nsp16 complex

    International Nuclear Information System (INIS)

    Debarnot, Claire; Imbert, Isabelle; Ferron, François; Gluais, Laure; Varlet, Isabelle; Papageorgiou, Nicolas; Bouvet, Mickaël; Lescar, Julien; Decroly, Etienne; Canard, Bruno

    2011-01-01

    The expression, purification and crystallization of the SARS coronavirus nsp16 RNA-cap AdoMet-dependent (nucleoside-2′O)-methyltransferase in complex with its activating factor nsp10 are reported. To date, the SARS coronavirus is the only known highly pathogenic human coronavirus. In 2003, it was responsible for a large outbreak associated with a 10% fatality rate. This positive RNA virus encodes a large replicase polyprotein made up of 16 gene products (nsp1–16), amongst which two methyltransferases, nsp14 and nsp16, are involved in viral mRNA cap formation. The crystal structure of nsp16 is unknown. Nsp16 is an RNA-cap AdoMet-dependent (nucleoside-2′-O-)-methyltransferase that is only active in the presence of nsp10. In this paper, the expression, purification and crystallization of nsp10 in complex with nsp16 are reported. The crystals diffracted to a resolution of 1.9 Å resolution and crystal structure determination is in progress

  5. Feline coronavirus replication is affected by both cyclophilin A and cyclophilin B.

    Science.gov (United States)

    Tanaka, Yoshikazu; Sato, Yuka; Sasaki, Takashi

    2017-02-01

    Feline coronavirus (FCoV) causes the fatal disease feline infectious peritonitis, which is currently incurable by drug treatment, and no effective vaccines are available. Cyclosporin A (CsA), a cyclophilin (Cyp) inhibitor, inhibits the replication of FCoV in vitro and in vivo as well as the replication of human and animal coronaviruses. However, the mechanism underlying the regulation of coronavirus replication by CsA is unknown. In this study, we analysed the role of Cyps in FCoV replication using knockdown and knockout cells specific to Cyps. Inhibition of CypA and CypB reduced FCoV replication, with replication in knockout cells being much less than that in knockdown cells. Furthermore, the proteins expressed by CypA and CypB harbouring mutations in their respective predicted peptidyl-prolyl cis-transisomerase active sites, which also alter the affinities between Cyps and CsA, inhibited FCoV replication. These findings indicate that the peptidyl-prolyl cis-transisomerase active sites of Cyps might be required for FCoV replication.

  6. Feline coronavirus: Insights into viral pathogenesis based on the spike protein structure and function.

    Science.gov (United States)

    Jaimes, Javier A; Whittaker, Gary R

    2018-04-01

    Feline coronavirus (FCoV) is an etiological agent that causes a benign enteric illness and the fatal systemic disease feline infectious peritonitis (FIP). The FCoV spike (S) protein is considered the viral regulator for binding and entry to the cell. This protein is also involved in FCoV tropism and virulence, as well as in the switch from enteric disease to FIP. This regulation is carried out by spike's major functions: receptor binding and virus-cell membrane fusion. In this review, we address important aspects in FCoV genetics, replication and pathogenesis, focusing on the role of S. To better understand this, FCoV S protein models were constructed, based on the human coronavirus NL63 (HCoV-NL63) S structure. We describe the specific structural characteristics of the FCoV S, in comparison with other coronavirus spikes. We also revise the biochemical events needed for FCoV S activation and its relation to the structural features of the protein. Copyright © 2018 Elsevier Inc. All rights reserved.

  7. Mutation in Spike Protein Cleavage Site and Pathogenesis of Feline Coronavirus

    Science.gov (United States)

    Licitra, Beth N.; Millet, Jean K.; Regan, Andrew D.; Hamilton, Brian S.; Rinaldi, Vera D.; Duhamel, Gerald E.

    2013-01-01

    Feline coronaviruses (FCoV) exist as 2 biotypes: feline enteric coronavirus (FECV) and feline infectious peritonitis virus (FIPV). FECV causes subclinical infections; FIPV causes feline infectious peritonitis (FIP), a systemic and fatal disease. It is thought that mutations in FECV enable infection of macrophages, causing FIP. However, the molecular basis for this biotype switch is unknown. We examined a furin cleavage site in the region between receptor-binding (S1) and fusion (S2) domains of the spike of serotype 1 FCoV. FECV sequences were compared with FIPV sequences. All FECVs had a conserved furin cleavage motif. For FIPV, there was a correlation with the disease and >1 substitution in the S1/S2 motif. Fluorogenic peptide assays confirmed that the substitutions modulate furin cleavage. We document a functionally relevant S1/S2 mutation that arises when FIP develops in a cat. These insights into FIP pathogenesis may be useful in development of diagnostic, prevention, and treatment measures against coronaviruses. PMID:23763835

  8. Feline Coronavirus 3c Protein: A Candidate for a Virulence Marker?

    Directory of Open Access Journals (Sweden)

    A. S. Hora

    2016-01-01

    Full Text Available Feline infectious peritonitis virus (FIPV is highly virulent and responsible for the highly fatal disease feline infectious peritonitis (FIP, whereas feline enteric coronavirus (FECV is widespread among the feline population and typically causes asymptomatic infections. Some candidates for genetic markers capable of differentiating these two pathotypes of a unique virus (feline coronavirus have been proposed by several studies. In the present survey, in order to search for markers that can differentiate FECV and FIPV, several clones of the 3a–c, E, and M genes were sequenced from samples obtained from cats with or without FIP. All genes showed genetic diversity and suggested the presence of FCoV mutant spectrum capable of producing a virulent pathotype in an individual-specific way. In addition, all the feline coronavirus FIPV strains demonstrated a truncated 3c protein, and the 3c gene was the only observed pathotypic marker for FCoVs, showing that 3c gene is a candidate marker for the distinction between the two pathotypes when the mutant spectrum is taken into account.

  9. Serine protease inhibitors of parasitic helminths.

    Science.gov (United States)

    Molehin, Adebayo J; Gobert, Geoffrey N; McManus, Donald P

    2012-05-01

    Serine protease inhibitors (serpins) are a superfamily of structurally conserved proteins that inhibit serine proteases and play key physiological roles in numerous biological systems such as blood coagulation, complement activation and inflammation. A number of serpins have now been identified in parasitic helminths with putative involvement in immune regulation and in parasite survival through interference with the host immune response. This review describes the serpins and smapins (small serine protease inhibitors) that have been identified in Ascaris spp., Brugia malayi, Ancylostoma caninum Onchocerca volvulus, Haemonchus contortus, Trichinella spiralis, Trichostrongylus vitrinus, Anisakis simplex, Trichuris suis, Schistosoma spp., Clonorchis sinensis, Paragonimus westermani and Echinococcus spp. and discusses their possible biological functions, including roles in host-parasite interplay and their evolutionary relationships.

  10. Tunable protease-activatable virus nanonodes.

    Science.gov (United States)

    Judd, Justin; Ho, Michelle L; Tiwari, Abhinav; Gomez, Eric J; Dempsey, Christopher; Van Vliet, Kim; Igoshin, Oleg A; Silberg, Jonathan J; Agbandje-McKenna, Mavis; Suh, Junghae

    2014-05-27

    We explored the unique signal integration properties of the self-assembling 60-mer protein capsid of adeno-associated virus (AAV), a clinically proven human gene therapy vector, by engineering proteolytic regulation of virus-receptor interactions such that processing of the capsid by proteases is required for infection. We find the transfer function of our engineered protease-activatable viruses (PAVs), relating the degree of proteolysis (input) to PAV activity (output), is highly nonlinear, likely due to increased polyvalency. By exploiting this dynamic polyvalency, in combination with the self-assembly properties of the virus capsid, we show that mosaic PAVs can be constructed that operate under a digital AND gate regime, where two different protease inputs are required for virus activation. These results show viruses can be engineered as signal-integrating nanoscale nodes whose functional properties are regulated by multiple proteolytic signals with easily tunable and predictable response surfaces, a promising development toward advanced control of gene delivery.

  11. Production of alkaline proteases by alkalophilic Bacillus subtilis ...

    African Journals Online (AJOL)

    Tuoyo Aghomotsegin

    2016-11-23

    Nov 23, 2016 ... Key words: Production, alkaline protease, Bacillus subtilis, animal wastes, enzyme activity. ... Generally, alkaline proteases are produced using submerged fermentation .... biopolymer concentrations were reported to have an influence ... adding nitrogenous compounds stimulate microorganism growth and ...

  12. Optimization of alkaline protease production and its fibrinolytic ...

    African Journals Online (AJOL)

    Optimization of alkaline protease production and its fibrinolytic activity from the ... nitrogen sources and sodium chloride concentration for protease production by the ... exploited to assist in protein degradation in various industrial processes.

  13. Purification and characterization of protease from Bacillus cereus ...

    African Journals Online (AJOL)

    Among them, SU12 isolate was selected due to its high enzyme production ... growth and protease production which includes different carbon and nitrogen sources, ... organism for the industrial production of the extracellular protease enzyme.

  14. Mosaic serine proteases in the mammalian central nervous system.

    Science.gov (United States)

    Mitsui, Shinichi; Watanabe, Yoshihisa; Yamaguchi, Tatsuyuki; Yamaguchi, Nozomi

    2008-01-01

    We review the structure and function of three kinds of mosaic serine proteases expressed in the mammalian central nervous system (CNS). Mosaic serine proteases have several domains in the proenzyme fragment, which modulate proteolytic function, and a protease domain at the C-terminus. Spinesin/TMPRSS5 is a transmembrane serine protease whose presynaptic distribution on motor neurons in the spinal cord suggests that it is significant for neuronal plasticity. Cell type-specific alternative splicing gives this protease diverse functions by modulating its intracellular localization. Motopsin/PRSS12 is a mosaic protease, and loss of its function causes mental retardation. Recent reports indicate the significance of this protease for cognitive function. We mention the fibrinolytic protease, tissue plasminogen activator (tPA), which has physiological and pathological functions in the CNS.

  15. Cysteine proteases as potential antigens in antiparasitic DNA vaccines

    DEFF Research Database (Denmark)

    Jørgensen, Louise von Gersdorff; Buchmann, Kurt

    2011-01-01

    En litteraturgennemgang af muligheder for at bruge cystein proteaser som antigener i antiparasitære vacciner.......En litteraturgennemgang af muligheder for at bruge cystein proteaser som antigener i antiparasitære vacciner....

  16. Screening of an FDA-approved compound library identifies four small-molecule inhibitors of Middle East respiratory syndrome coronavirus replication in cell culture

    NARCIS (Netherlands)

    A.H. de Wilde (Adriaan); D. Jochmans (Dirk); C.C. Posthuma (Clara); J.C. Zevenhoven-Dobbe (Jessika); S. van Nieuwkoop (Stefan); T.M. Bestebroer (Theo); B.G. van den Hoogen (Bernadette); J. Neyts; E.J. Snijder (Eric)

    2014-01-01

    textabstractCoronaviruses can cause respiratory and enteric disease in a wide variety of human and animal hosts. The 2003 outbreak of severe acute respiratory syndrome (SARS) first demonstrated the potentially lethal consequences of zoonotic coronavirus infections in humans. In 2012, a similar

  17. Cleavage of group 1 coronavirus spike proteins: how furin cleavage is traded off against heparan sulfate binding upon cell culture adaptation

    NARCIS (Netherlands)

    Haan, de C.A.M.; Haijema, B.J.; Schellen, P.; Wichgers Schreur, P.J.; Lintelo, te E.; Vennema, H.; Rottier, P.J.M.

    2008-01-01

    A longstanding enigmatic feature of the group 1 coronaviruses is the uncleaved phenotype of their spike protein, an exceptional property among class I fusion proteins. Here, however, we show that some group 1 coronavirus spike proteins carry a furin enzyme recognition motif and can actually be

  18. Lack of association between infection with a novel human coronavirus (HCoV), HCoV-NH, and Kawasaki disease in Taiwan

    NARCIS (Netherlands)

    Chang, Luan-Yin; Chiang, Bor-Luen; Kao, Chuan-Liang; Wu, Mei-Hwan; Chen, Pei-Jer; Berkhout, Ben; Yang, Hui-Ching; Huang, Li-Min

    2006-01-01

    We investigated whether infection with a novel human coronavirus (HCoV), called "New Haven coronavirus" (HCoV-NH)--which is similar to and likely represents the same species as another novel HCoV, HCoV-NL63--is associated with Kawasaki disease (KD) in Taiwan. Fifty-three patients with KD were

  19. Pengaruh PH dan Suhu terhadap Aktivitas Protease Penicillium SP.

    OpenAIRE

    Yusriah, Yusriah; Kuswytasari, Nengah Dwianita

    2013-01-01

    Tujuan penelitian ini adalah untuk mengetahui pengaruh pH dan suhu terhadap aktivitas protease pada Penicillium sp.3 T3f2. Selanjutnya, isolat Penicillium sp. di kultur dalam media produksi protease untuk menghasilkan protease. Suhu yang digunakan adalah 300 – 500C sedangkan pH-nya 4 – 8. Aktivitas protease ditentukan dan diukur dengan spektrofotometer pada panjang gelombang 275 nm, dengan kasein sebagai substrat. Berdasarkan uji ANOVA yang dilanjutkan dengan uji Duncan dengan taraf kepercaya...

  20. High throughput in vivo protease inhibitor selection platform

    DEFF Research Database (Denmark)

    2017-01-01

    The invention relates to a recombinant microbial cell comprising a selection platform for screening for a protease inhibitor, wherein the platform comprises transgenes encoding a protease having selective peptide bond cleavage activity at a recognition site amino acid sequence; and transgenes...... platform for screening for a protease inhibitor....

  1. Dataset of cocoa aspartic protease cleavage sites

    Directory of Open Access Journals (Sweden)

    Katharina Janek

    2016-09-01

    Full Text Available The data provide information in support of the research article, “The cleavage specificity of the aspartic protease of cocoa beans involved in the generation of the cocoa-specific aroma precursors” (Janek et al., 2016 [1]. Three different protein substrates were partially digested with the aspartic protease isolated from cocoa beans and commercial pepsin, respectively. The obtained peptide fragments were analyzed by matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/TOF-MS/MS and identified using the MASCOT server. The N- and C-terminal ends of the peptide fragments were used to identify the corresponding in-vitro cleavage sites by comparison with the amino acid sequences of the substrate proteins. The same procedure was applied to identify the cleavage sites used by the cocoa aspartic protease during cocoa fermentation starting from the published amino acid sequences of oligopeptides isolated from fermented cocoa beans. Keywords: Aspartic protease, Cleavage sites, Cocoa, In-vitro proteolysis, Mass spectrometry, Peptides

  2. Lipase and protease extraction from activated sludge

    DEFF Research Database (Denmark)

    Gessesse, Amare; Dueholm, Thomas; Petersen, Steffen B.

    2003-01-01

    of gentle and efficient enzyme extraction methods from environmental samples is very important. In this study we present a method for the extraction of lipases and proteases from activated sludge using the non-ionic detergent Triton X-100, EDTA, and cation exchange resin (CER), alone or in combination...

  3. HIV-1 protease-induced apoptosis

    Czech Academy of Sciences Publication Activity Database

    Rumlová, Michaela; Křížová, Ivana; Keprová, Alena; Hadravová, Romana; Doležal, Michal; Strohalmová, Karolína; Pichová, Iva; Hájek, Miroslav; Ruml, T.

    2014-01-01

    Roč. 11, May 20 (2014), 37/1-37/15 ISSN 1742-4690 R&D Projects: GA ČR GA204/09/1388 Institutional support: RVO:61388963 Keywords : HIV protease * BCA3 * AKIP-1 * apoptosis * mitochondria Subject RIV: EE - Microbiology, Virology Impact factor: 4.185, year: 2014 http://www.retrovirology.com/content/11/1/37

  4. Bacterial proteases: targets for diagnostics and therapy

    NARCIS (Netherlands)

    Kaman, W.E.; Hays, J.P.; Endtz, H.P.; Bikker, F.J.

    2014-01-01

    Proteases are essential for the proliferation and growth of bacteria, and are also known to contribute to bacterial virulence. This makes them interesting candidates as diagnostic and therapeutic targets for infectious diseases. In this review, the authors discuss the most recent developments and

  5. Novel peptide-based protease inhibitors

    DEFF Research Database (Denmark)

    Roodbeen, Renée

    of novel peptide-based protease inhibitors, efforts were made towards improved methods for peptide synthesis. The coupling of Fmoc-amino acids onto N-methylated peptidyl resins was investigated. These couplings can be low yielding and the effect of the use of microwave heating combined with the coupling...

  6. Isolation and Characterization of Dromedary Camel Coronavirus UAE-HKU23 from Dromedaries of the Middle East: Minimal Serological Cross-Reactivity between MERS Coronavirus and Dromedary Camel Coronavirus UAE-HKU23

    Directory of Open Access Journals (Sweden)

    Patrick C. Y. Woo

    2016-05-01

    Full Text Available Recently, we reported the discovery of a dromedary camel coronavirus UAE-HKU23 (DcCoV UAE-HKU23 from dromedaries in the Middle East. In this study, DcCoV UAE-HKU23 was successfully isolated in two of the 14 dromedary fecal samples using HRT-18G cells, with cytopathic effects observed five days after inoculation. Northern blot analysis revealed at least seven distinct RNA species, corresponding to predicted subgenomic mRNAs and confirming the core sequence of transcription regulatory sequence motifs as 5′-UCUAAAC-3′ as we predicted previously. Antibodies against DcCoV UAE-HKU23 were detected in 58 (98.3% and 59 (100% of the 59 dromedary sera by immunofluorescence and neutralization antibody tests, respectively. There was significant correlation between the antibody titers determined by immunofluorescence and neutralization assays (Pearson coefficient = 0.525, p < 0.0001. Immunization of mice using recombinant N proteins of DcCoV UAE-HKU23 and Middle East respiratory syndrome coronavirus (MERS-CoV, respectively, and heat-inactivated DcCoV UAE-HKU23 showed minimal cross-antigenicity between DcCoV UAE-HKU23 and MERS-CoV by Western blot and neutralization antibody assays. Codon usage and genetic distance analysis of RdRp, S and N genes showed that the 14 strains of DcCoV UAE-HKU23 formed a distinct cluster, separated from those of other closely related members of Betacoronavirus 1, including alpaca CoV, confirming that DcCoV UAE-HKU23 is a novel member of Betacoronavirus 1.

  7. A novel protease activity assay using a protease-responsive chaperone protein

    International Nuclear Information System (INIS)

    Sao, Kentaro; Murata, Masaharu; Fujisaki, Yuri; Umezaki, Kaori; Mori, Takeshi; Niidome, Takuro; Katayama, Yoshiki; Hashizume, Makoto

    2009-01-01

    Protease activity assays are important for elucidating protease function and for developing new therapeutic agents. In this study, a novel turbidimetric method for determining the protease activity using a protease-responsive chaperone protein is described. For this purpose, a recombinant small heat-shock protein (sHSP) with an introduced Factor Xa protease recognition site was synthesized in bacteria. This recombinant mutant, FXa-HSP, exhibited chaperone-like activity at high temperatures in cell lysates. However, the chaperone-like activity of FXa-HSP decreased dramatically following treatment with Factor Xa. Protein precipitation was subsequently observed in the cell lysates. The reaction was Factor Xa concentration-dependent and was quantitatively suppressed by a specific inhibitor for Factor Xa. Protein aggregation was detected by a simple method based on turbidimetry. The results clearly demonstrate that this assay is an effective, easy-to-use method for determining protease activities without the requirement of labeling procedures and the use of radioisotopes.

  8. A novel protease activity assay using a protease-responsive chaperone protein

    Energy Technology Data Exchange (ETDEWEB)

    Sao, Kentaro [Graduate School of Systems Life Sciences, Kyushu University, 744 Motooka Nishi-ku, Fukuoka 819-0395 (Japan); Murata, Masaharu, E-mail: m-murata@dem.med.kyushu-u.ac.jp [Department of Advanced Medical Initiatives, Faculty of Medical Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku Fukuoka 812-8582 (Japan); Fujisaki, Yuri; Umezaki, Kaori [Department of Advanced Medical Initiatives, Faculty of Medical Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku Fukuoka 812-8582 (Japan); Mori, Takeshi; Niidome, Takuro; Katayama, Yoshiki [Graduate School of Systems Life Sciences, Kyushu University, 744 Motooka Nishi-ku, Fukuoka 819-0395 (Japan); Department of Applied Chemistry, Faculty of Engineering, Kyushu University, Nishi-ku Fukuoka 819-0395 (Japan); Center for Future Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Hashizume, Makoto [Department of Advanced Medical Initiatives, Faculty of Medical Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku Fukuoka 812-8582 (Japan)

    2009-06-05

    Protease activity assays are important for elucidating protease function and for developing new therapeutic agents. In this study, a novel turbidimetric method for determining the protease activity using a protease-responsive chaperone protein is described. For this purpose, a recombinant small heat-shock protein (sHSP) with an introduced Factor Xa protease recognition site was synthesized in bacteria. This recombinant mutant, FXa-HSP, exhibited chaperone-like activity at high temperatures in cell lysates. However, the chaperone-like activity of FXa-HSP decreased dramatically following treatment with Factor Xa. Protein precipitation was subsequently observed in the cell lysates. The reaction was Factor Xa concentration-dependent and was quantitatively suppressed by a specific inhibitor for Factor Xa. Protein aggregation was detected by a simple method based on turbidimetry. The results clearly demonstrate that this assay is an effective, easy-to-use method for determining protease activities without the requirement of labeling procedures and the use of radioisotopes.

  9. Proteases and protease inhibitors of urinary extracellular vesicles in diabetic nephropathy.

    Science.gov (United States)

    Musante, Luca; Tataruch, Dorota; Gu, Dongfeng; Liu, Xinyu; Forsblom, Carol; Groop, Per-Henrik; Holthofer, Harry

    2015-01-01

    Diabetic nephropathy (DN) is one of the major complications of diabetes mellitus (DM), leads to chronic kidney disease (CKD), and, ultimately, is the main cause for end-stage kidney disease (ESKD). Beyond urinary albumin, no reliable biomarkers are available for accurate early diagnostics. Urinary extracellular vesicles (UEVs) have recently emerged as an interesting source of diagnostic and prognostic disease biomarkers. Here we used a protease and respective protease inhibitor array to profile urines of type 1 diabetes patients at different stages of kidney involvement. Urine samples were divided into groups based on the level of albuminuria and UEVs isolated by hydrostatic dialysis and screened for relative changes of 34 different proteases and 32 protease inhibitors, respectively. Interestingly, myeloblastin and its natural inhibitor elafin showed an increase in the normo- and microalbuminuric groups. Similarly, a characteristic pattern was observed in the array of protease inhibitors, with a marked increase of cystatin B, natural inhibitor of cathepsins L, H, and B as well as of neutrophil gelatinase-associated Lipocalin (NGAL) in the normoalbuminuric group. This study shows for the first time the distinctive alterations in comprehensive protease profiles of UEVs in diabetic nephropathy and uncovers intriguing mechanistic, prognostic, and diagnostic features of kidney damage in diabetes.

  10. Proteases and Protease Inhibitors of Urinary Extracellular Vesicles in Diabetic Nephropathy

    Directory of Open Access Journals (Sweden)

    Luca Musante

    2015-01-01

    Full Text Available Diabetic nephropathy (DN is one of the major complications of diabetes mellitus (DM, leads to chronic kidney disease (CKD, and, ultimately, is the main cause for end-stage kidney disease (ESKD. Beyond urinary albumin, no reliable biomarkers are available for accurate early diagnostics. Urinary extracellular vesicles (UEVs have recently emerged as an interesting source of diagnostic and prognostic disease biomarkers. Here we used a protease and respective protease inhibitor array to profile urines of type 1 diabetes patients at different stages of kidney involvement. Urine samples were divided into groups based on the level of albuminuria and UEVs isolated by hydrostatic dialysis and screened for relative changes of 34 different proteases and 32 protease inhibitors, respectively. Interestingly, myeloblastin and its natural inhibitor elafin showed an increase in the normo- and microalbuminuric groups. Similarly, a characteristic pattern was observed in the array of protease inhibitors, with a marked increase of cystatin B, natural inhibitor of cathepsins L, H, and B as well as of neutrophil gelatinase-associated Lipocalin (NGAL in the normoalbuminuric group. This study shows for the first time the distinctive alterations in comprehensive protease profiles of UEVs in diabetic nephropathy and uncovers intriguing mechanistic, prognostic, and diagnostic features of kidney damage in diabetes.

  11. Group 2 coronaviruses prevent immediate early interferon induction by protection of viral RNA from host cell recognition

    International Nuclear Information System (INIS)

    Versteeg, Gijs A.; Bredenbeek, Peter J.; Worm, Sjoerd H.E. van den; Spaan, Willy J.M.

    2007-01-01

    Many viruses encode antagonists to prevent interferon (IFN) induction. Infection of fibroblasts with the murine hepatitis coronavirus (MHV) and SARS-coronavirus (SARS-CoV) did not result in nuclear translocation of interferon-regulatory factor 3 (IRF3), a key transcription factor involved in IFN induction, and induction of IFN mRNA transcription. Furthermore, MHV and SARS-CoV infection could not prevent IFN induction by poly (I:C) or Sendai virus, suggesting that these CoVs do not inactivate IRF3-mediated transcription regulation, but apparently prevent detection of replicative RNA by cellular sensory molecules. Our data indicate that shielding of viral RNA to host cell sensors might be the main general mechanism for coronaviruses to prevent IFN induction

  12. HIV protease drug resistance and its impact on inhibitor design.

    Science.gov (United States)

    Ala, P J; Rodgers, J D; Chang, C H

    1999-07-01

    The primary cause of resistance to the currently available HIV protease inhibitors is the accumulation of multiple mutations in the viral protease. So far more than 20 substitutions have been observed in the active site, dimer interface, surface loops and flaps of the homodimer. While many mutations reduce the protease's affinity for inhibitors, others appear to enhance its catalytic efficiency. This high degree of genetic flexibility has made the protease an elusive drug target. The design of the next generation of HIV protease inhibitors will be discussed in light of the current structural information.

  13. Targeting membrane-bound viral RNA synthesis reveals potent inhibition of diverse coronaviruses including the middle East respiratory syndrome virus.

    Directory of Open Access Journals (Sweden)

    Anna Lundin

    2014-05-01

    Full Text Available Coronaviruses raise serious concerns as emerging zoonotic viruses without specific antiviral drugs available. Here we screened a collection of 16671 diverse compounds for anti-human coronavirus 229E activity and identified an inhibitor, designated K22, that specifically targets membrane-bound coronaviral RNA synthesis. K22 exerts most potent antiviral activity after virus entry during an early step of the viral life cycle. Specifically, the formation of double membrane vesicles (DMVs, a hallmark of coronavirus replication, was greatly impaired upon K22 treatment accompanied by near-complete inhibition of viral RNA synthesis. K22-resistant viruses contained substitutions in non-structural protein 6 (nsp6, a membrane-spanning integral component of the viral replication complex implicated in DMV formation, corroborating that K22 targets membrane bound viral RNA synthesis. Besides K22 resistance, the nsp6 mutants induced a reduced number of DMVs, displayed decreased specific infectivity, while RNA synthesis was not affected. Importantly, K22 inhibits a broad range of coronaviruses, including Middle East respiratory syndrome coronavirus (MERS-CoV, and efficient inhibition was achieved in primary human epithelia cultures representing the entry port of human coronavirus infection. Collectively, this study proposes an evolutionary conserved step in the life cycle of positive-stranded RNA viruses, the recruitment of cellular membranes for viral replication, as vulnerable and, most importantly, druggable target for antiviral intervention. We expect this mode of action to serve as a paradigm for the development of potent antiviral drugs to combat many animal and human virus infections.

  14. Microbial alkaline proteases: Optimization of production parameters and their properties

    Directory of Open Access Journals (Sweden)

    Kanupriya Miglani Sharma

    2017-06-01

    Full Text Available Proteases are hydrolytic enzymes capable of degrading proteins into small peptides and amino acids. They account for nearly 60% of the total industrial enzyme market. Proteases are extensively exploited commercially, in food, pharmaceutical, leather and detergent industry. Given their potential use, there has been renewed interest in the discovery of proteases with novel properties and a constant thrust to optimize the enzyme production. This review summarizes a fraction of the enormous reports available on various aspects of alkaline proteases. Diverse sources for isolation of alkaline protease producing microorganisms are reported. The various nutritional and environmental parameters affecting the production of alkaline proteases in submerged and solid state fermentation are described. The enzymatic and physicochemical properties of alkaline proteases from several microorganisms are discussed which can help to identify enzymes with high activity and stability over extreme pH and temperature, so that they can be developed for industrial applications.

  15. Pathophysiological significance and therapeutic applications of snake venom protease inhibitors.

    Science.gov (United States)

    Thakur, Rupamoni; Mukherjee, Ashis K

    2017-06-01

    Protease inhibitors are important constituents of snake venom and play important roles in the pathophysiology of snakebite. Recently, research on snake venom protease inhibitors has provided valuable information to decipher the molecular details of various biological processes and offer insight for the development of some therapeutically important molecules from snake venom. The process of blood coagulation and fibrinolysis, in addition to affecting platelet function, are well known as the major targets of several snake venom protease inhibitors. This review summarizes the structure-functional aspects of snake venom protease inhibitors that have been described to date. Because diverse biological functions have been demonstrated by protease inhibitors, a comparative overview of their pharmacological and pathophysiological properties is also highlighted. In addition, since most snake venom protease inhibitors are non-toxic on their own, this review evaluates the different roles of individual protease inhibitors that could lead to the identification of drug candidates and diagnostic molecules. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Isolation of avian infectious bronchitis coronavirus from domestic peafowl (Pavo cristatus) and teal (Anas).

    Science.gov (United States)

    Liu, Shengwang; Chen, Jianfei; Chen, Jinding; Kong, Xiangang; Shao, Yuhao; Han, Zongxi; Feng, Li; Cai, Xuehui; Gu, Shoulin; Liu, Ming

    2005-03-01

    Coronavirus-like viruses, designated peafowl/China/LKQ3/2003 (pf/CH/LKQ3/03) and teal/China/LDT3/2003 (tl/CH/LDT3/03), were isolated from a peafowl and a teal during virological surveillance in Guangdong province, China. Partial genomic sequence analysis showed that these isolates had the S-3-M-5-N gene order that is typical of avian coronaviruses. The spike, membrane and nucleocapsid protein genes of pf/CH/LKQ3/03 had >99 % identity to those of the avian infectious bronchitis coronavirus H120 vaccine strain (Massachusetts serotype) and other Massachusetts serotype isolates. Furthermore, when pf/CH/LKQ3/03 was inoculated experimentally into chickens (specific-pathogen-free), no disease signs were apparent. tl/CH/LDT3/03 had a spike protein gene with 95 % identity to that of a Chinese infectious bronchitis virus (IBV) isolate, although more extensive sequencing revealed the possibility that this strain may have undergone recombination. When inoculated into chickens, tl/CH/LDT3/03 resulted in the death of birds from nephritis. Taken together, this information suggests that pf/CH/LKQ3/03 might be a revertant, attenuated vaccine IBV strain, whereas tl/CH/LDT3/03 is a nephropathogenic field IBV strain, generated through recombination. The replication and non-pathogenic nature of IBV in domestic peafowl and teal under field conditions raises questions as to the role of these hosts as carriers of IBV and the potential that they may have to transmit virus to susceptible chicken populations.

  17. Establishment of feline intestinal epithelial cell cultures for the propagation and study of feline enteric coronaviruses

    Science.gov (United States)

    2013-01-01

    Feline infectious peritonitis (FIP) is the most feared infectious cause of death in cats, induced by feline infectious peritonitis virus (FIPV). This coronavirus is a virulent mutant of the harmless, ubiquitous feline enteric coronavirus (FECV). To date, feline coronavirus (FCoV) research has been hampered by the lack of susceptible cell lines for the propagation of serotype I FCoVs. In this study, long-term feline intestinal epithelial cell cultures were established from primary ileocytes and colonocytes by simian virus 40 (SV40) T-antigen- and human Telomerase Reverse Transcriptase (hTERT)-induced immortalization. Subsequently, these cultures were evaluated for their usability in FCoV research. Firstly, the replication capacity of the serotype II strains WSU 79–1683 and WSU 79–1146 was studied in the continuous cultures as was done for the primary cultures. In accordance with the results obtained in primary cultures, FCoV WSU 79–1683 still replicated significantly more efficient compared to FCoV WSU 79–1146 in both continuous cultures. In addition, the cultures were inoculated with faecal suspensions from healthy cats and with faecal or tissue suspensions from FIP cats. The cultures were susceptible to infection with different serotype I enteric strains and two of these strains were further propagated. No infection was seen in cultures inoculated with FIPV tissue homogenates. In conclusion, a new reliable model for FCoV investigation and growth of enteric field strains was established. In contrast to FIPV strains, FECVs showed a clear tropism for intestinal epithelial cells, giving an explanation for the observation that FECV is the main pathotype circulating among cats. PMID:23964891

  18. Automated extraction protocol for quantification of SARS-Coronavirus RNA in serum: an evaluation study

    Directory of Open Access Journals (Sweden)

    Lui Wing-bong

    2006-02-01

    Full Text Available Abstract Background We have previously developed a test for the diagnosis and prognostic assessment of the severe acute respiratory syndrome (SARS based on the detection of the SARS-coronavirus RNA in serum by real-time quantitative reverse transcriptase polymerase chain reaction (RT-PCR. In this study, we evaluated the feasibility of automating the serum RNA extraction procedure in order to increase the throughput of the assay. Methods An automated nucleic acid extraction platform using the MagNA Pure LC instrument (Roche Diagnostics was evaluated. We developed a modified protocol in compliance with the recommended biosafety guidelines from the World Health Organization based on the use of the MagNA Pure total nucleic acid large volume isolation kit for the extraction of SARS-coronavirus RNA. The modified protocol was compared with a column-based extraction kit (QIAamp viral RNA mini kit, Qiagen for quantitative performance, analytical sensitivity and precision. Results The newly developed automated protocol was shown to be free from carry-over contamination and have comparable performance with other standard protocols and kits designed for the MagNA Pure LC instrument. However, the automated method was found to be less sensitive, less precise and led to consistently lower serum SARS-coronavirus concentrations when compared with the column-based extraction method. Conclusion As the diagnostic efficiency and prognostic value of the serum SARS-CoV RNA RT-PCR test is critically associated with the analytical sensitivity and quantitative performance contributed both by the RNA extraction and RT-PCR components of the test, we recommend the use of the column-based manual RNA extraction method.

  19. Structure and inhibition of the SARS coronavirus envelope protein ion channel.

    Directory of Open Access Journals (Sweden)

    Konstantin Pervushin

    2009-07-01

    Full Text Available The envelope (E protein from coronaviruses is a small polypeptide that contains at least one alpha-helical transmembrane domain. Absence, or inactivation, of E protein results in attenuated viruses, due to alterations in either virion morphology or tropism. Apart from its morphogenetic properties, protein E has been reported to have membrane permeabilizing activity. Further, the drug hexamethylene amiloride (HMA, but not amiloride, inhibited in vitro ion channel activity of some synthetic coronavirus E proteins, and also viral replication. We have previously shown for the coronavirus species responsible for severe acute respiratory syndrome (SARS-CoV that the transmembrane domain of E protein (ETM forms pentameric alpha-helical bundles that are likely responsible for the observed channel activity. Herein, using solution NMR in dodecylphosphatidylcholine micelles and energy minimization, we have obtained a model of this channel which features regular alpha-helices that form a pentameric left-handed parallel bundle. The drug HMA was found to bind inside the lumen of the channel, at both the C-terminal and the N-terminal openings, and, in contrast to amiloride, induced additional chemical shifts in ETM. Full length SARS-CoV E displayed channel activity when transiently expressed in human embryonic kidney 293 (HEK-293 cells in a whole-cell patch clamp set-up. This activity was significantly reduced by hexamethylene amiloride (HMA, but not by amiloride. The channel structure presented herein provides a possible rationale for inhibition, and a platform for future structure-based drug design of this potential pharmacological target.

  20. SARS-coronavirus replication is supported by a reticulovesicular network of modified endoplasmic reticulum.

    Directory of Open Access Journals (Sweden)

    Kèvin Knoops

    2008-09-01

    Full Text Available Positive-strand RNA viruses, a large group including human pathogens such as SARS-coronavirus (SARS-CoV, replicate in the cytoplasm of infected host cells. Their replication complexes are commonly associated with modified host cell membranes. Membrane structures supporting viral RNA synthesis range from distinct spherular membrane invaginations to more elaborate webs of packed membranes and vesicles. Generally, their ultrastructure, morphogenesis, and exact role in viral replication remain to be defined. Poorly characterized double-membrane vesicles (DMVs were previously implicated in SARS-CoV RNA synthesis. We have now applied electron tomography of cryofixed infected cells for the three-dimensional imaging of coronavirus-induced membrane alterations at high resolution. Our analysis defines a unique reticulovesicular network of modified endoplasmic reticulum that integrates convoluted membranes, numerous interconnected DMVs (diameter 200-300 nm, and "vesicle packets" apparently arising from DMV merger. The convoluted membranes were most abundantly immunolabeled for viral replicase subunits. However, double-stranded RNA, presumably revealing the site of viral RNA synthesis, mainly localized to the DMV interior. Since we could not discern a connection between DMV interior and cytosol, our analysis raises several questions about the mechanism of DMV formation and the actual site of SARS-CoV RNA synthesis. Our data document the extensive virus-induced reorganization of host cell membranes into a network that is used to organize viral replication and possibly hide replicating RNA from antiviral defense mechanisms. Together with biochemical studies of the viral enzyme complex, our ultrastructural description of this "replication network" will aid to further dissect the early stages of the coronavirus life cycle and its virus-host interactions.

  1. Cooperation of an RNA Packaging Signal and a Viral Envelope Protein in Coronavirus RNA Packaging

    OpenAIRE

    Narayanan, Krishna; Makino, Shinji

    2001-01-01

    Murine coronavirus mouse hepatitis virus (MHV) produces a genome-length mRNA, mRNA 1, and six or seven species of subgenomic mRNAs in infected cells. Among these mRNAs, only mRNA 1 is efficiently packaged into MHV particles. MHV N protein binds to all MHV mRNAs, whereas envelope M protein interacts only with mRNA 1. This M protein-mRNA 1 interaction most probably determines the selective packaging of mRNA 1 into MHV particles. A short cis-acting MHV RNA packaging signal is necessary and suffi...

  2. Candidates in Astroviruses, Seadornaviruses, Cytorhabdoviruses and Coronaviruses for +1 frame overlapping genes accessed by leaky scanning

    Directory of Open Access Journals (Sweden)

    Atkins John F

    2010-01-01

    Full Text Available Abstract Background Overlapping genes are common in RNA viruses where they serve as a mechanism to optimize the coding potential of compact genomes. However, annotation of overlapping genes can be difficult using conventional gene-finding software. Recently we have been using a number of complementary approaches to systematically identify previously undetected overlapping genes in RNA virus genomes. In this article we gather together a number of promising candidate new overlapping genes that may be of interest to the community. Results Overlapping gene predictions are presented for the astroviruses, seadornaviruses, cytorhabdoviruses and coronaviruses (families Astroviridae, Reoviridae, Rhabdoviridae and Coronaviridae, respectively.

  3. A cyclic peptidic serine protease inhibitor

    DEFF Research Database (Denmark)

    Zhao, Baoyu; Xu, Peng; Jiang, Longguang

    2014-01-01

    Peptides are attracting increasing interest as protease inhibitors. Here, we demonstrate a new inhibitory mechanism and a new type of exosite interactions for a phage-displayed peptide library-derived competitive inhibitor, mupain-1 (CPAYSRYLDC), of the serine protease murine urokinase...... pocket, its carbonyl group aligning improperly relative to Ser195 and the oxyanion hole, explaining why the peptide is an inhibitor rather than a substrate. Substitution of the P1 Arg with novel unnatural Arg analogues with aliphatic or aromatic ring structures led to an increased affinity, depending......, in spite of a less favorable binding entropy and loss of a polar interaction. We conclude that increased flexibility of the peptide allows more favorable exosite interactions, which, in combination with the use of novel Arg analogues as P1 residues, can be used to manipulate the affinity and specificity...

  4. Luminometric method for screening retroviral protease inhibitors

    Czech Academy of Sciences Publication Activity Database

    Horáková, D.; Rumlová, Michaela; Pichová, Iva; Ruml, Tomáš

    2005-01-01

    Roč. 345, č. 1 (2005), s. 96-101 ISSN 0003-2697 R&D Projects: GA AV ČR(CZ) IAA4055304; GA MŠk(CZ) 1M0508; GA MŠk(CZ) 1M0520 Institutional research plan: CEZ:AV0Z40550506 Keywords : retroviral protease * inhibitors * luminescent assay Subject RIV: CE - Biochemistry Impact factor: 2.670, year: 2005

  5. Dysregulation of protease and protease inhibitors in a mouse model of human pelvic organ prolapse.

    Directory of Open Access Journals (Sweden)

    Madhusudhan Budatha

    Full Text Available Mice deficient for the fibulin-5 gene (Fbln5(-/- develop pelvic organ prolapse (POP due to compromised elastic fibers and upregulation of matrix metalloprotease (MMP-9. Here, we used casein zymography, inhibitor profiling, affinity pull-down, and mass spectrometry to discover additional protease upregulated in the vaginal wall of Fbln5(-/- mice, herein named V1 (25 kDa. V1 was a serine protease with trypsin-like activity similar to protease, serine (PRSS 3, a major extrapancreatic trypsinogen, was optimum at pH 8.0, and predominantly detected in estrogenized vaginal epithelium of Fbln5(-/- mice. PRSS3 was (a localized in epithelial secretions, (b detected in media of vaginal organ culture from both Fbln5(-/- and wild type mice, and (c cleaved fibulin-5 in vitro. Expression of two serine protease inhibitors [Serpina1a (α1-antitrypsin and Elafin] was dysregulated in Fbln5(-/- epithelium. Finally, we confirmed that PRSS3 was expressed in human vaginal epithelium and that SERPINA1 and Elafin were downregulated in vaginal tissues from women with POP. These data collectively suggest that the balance between proteases and their inhibitors contributes to support of the pelvic organs in humans and mice.

  6. Role of Proteases in Chronic Obstructive Pulmonary Disease

    Directory of Open Access Journals (Sweden)

    Kailash C. Pandey

    2017-08-01

    Full Text Available Chronic obstructive pulmonary disease (COPD is generally associated with progressive destruction of airways and lung parenchyma. Various factors play an important role in the development and progression of COPD, like imbalance of proteases, environmental and genetic factors and oxidative stress. This review is specifically focused on the role of proteases and their imbalance in COPD. There are three classes (serine, mettalo, and cysteine of proteases involved in COPD. In serine proteases, neutrophil elastase, cathepsin G, and proteinase-3 are involved in destruction of alveolar tissue. Matrix-mettaloproteinase-9, 12, 13, plays an influential role in severity of COPD. Among cysteine proteases, caspase-3, caspases-8 and caspase-9 play an important role in controlling apoptosis. These proteases activities can be regulated by inhibitors like α-1-antitrypsin, neutrophil elastase inhibitor, and leukocyte protease inhibitor. Studies suggest that neutrophil elastase may be a therapeutic target for COPD, and specific inhibitor against this enzyme has potential role to control the disease. Current study suggests that Dipeptidyl Peptidase IV is a potential marker for COPD. Since the expression of proteases and its inhibitors play an important role in COPD pathogenesis, therefore, it is worth investigating the role of proteases and their regulation. Understanding the biochemical basis of COPD pathogenesis using advanced tools in protease biochemistry and aiming toward translational research from bench-to-bedside will have great impact to deal with this health problem.

  7. PARTIAL PURIFICATION AND CHARACTERIZATION OF ALKALOPHILIC PROTEASE FROM PSEUDOMONAS AERUGINOSA

    Directory of Open Access Journals (Sweden)

    R. Satheeskumar

    2013-10-01

    Full Text Available Partial purification and characterization of alkalophilic protease production from Pseudomonas aeruginosa was isolated from the gut of marine and coastal waters shrimp Penaeus monodon. The protease production was assayed in submerged fermentation to produce maximum protease activity (423 ± 0.09 U/ml. The enzyme was precipitated with ammonium sulphate and partially purified by ion exchange chromatography through DEAE Sephadex A-50 column. In 10th fraction showed maximum protease activity (734 ± 0.18 U/ml with increase in purification fold. The molecular weight of protease from Pseudomonas aeruginosa was recorded as 60 kDa. The stability of protease was tested at various pH and temperature; it showed maximum protease activity at pH-9 and temperature 50ºC. Among the various surfactants tested for enzyme stability, maximum activity was retained in poly ethylene glycol. The compatibility of protease enzyme with various commercial detergents; the enzyme retained maximum protease activity in tide. The results are indicated that all these properties make the bacterial proteases are most suitable for wide industrial applications.

  8. Understanding serine proteases implications on Leishmania spp lifecycle.

    Science.gov (United States)

    Alves, Carlos Roberto; Souza, Raquel Santos de; Charret, Karen Dos Santos; Côrtes, Luzia Monteiro de Castro; Sá-Silva, Matheus Pereira de; Barral-Veloso, Laura; Oliveira, Luiz Filipe Gonçalves; da Silva, Franklin Souza

    2018-01-01

    Serine proteases have significant functions over a broad range of relevant biological processes to the Leishmania spp lifecycle. Data gathered here present an update on the Leishmania spp serine proteases and the status of these enzymes as part of the parasite degradome. The serine protease genes (n = 26 to 28) in Leishmania spp, which encode proteins with a wide range of molecular masses (35 kDa-115 kDa), are described along with their degrees of chromosomal and allelic synteny. Amid 17 putative Leishmania spp serine proteases, only ∼18% were experimentally demonstrated, as: signal peptidases that remove the signal peptide from secretory pre-proteins, maturases of other proteins and with metacaspase-like activity. These enzymes include those of clans SB, SC and SF. Classical inhibitors of serine proteases are used as tools for the characterization and investigation of Leishmania spp. Endogenous serine protease inhibitors, which are ecotin-like, can act modulating host actions. However, crude or synthetic based-natural serine protease inhibitors, such as potato tuber extract, Stichodactyla helianthus protease inhibitor I, fukugetin and epoxy-α-lapachone act on parasitic serine proteases and are promising leishmanicidal agents. The functional interrelationship between serine proteases and other Leishmania spp proteins demonstrate essential functions of these enzymes in parasite physiology and therefore their value as targets for leishmaniasis treatment. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Corruption of innate immunity by bacterial proteases.

    Science.gov (United States)

    Potempa, Jan; Pike, Robert N

    2009-01-01

    The innate immune system of the human body has developed numerous mechanisms to control endogenous and exogenous bacteria and thus prevent infections by these microorganisms. These mechanisms range from physical barriers such as the skin or mucosal epithelium to a sophisticated array of molecules and cells that function to suppress or prevent bacterial infection. Many bacteria express a variety of proteases, ranging from non-specific and powerful enzymes that degrade many proteins involved in innate immunity to proteases that are extremely precise and specific in their mode of action. Here we have assembled a comprehensive picture of how bacterial proteases affect the host's innate immune system to gain advantage and cause infection. This picture is far from being complete since the numbers of mechanisms utilized are as astonishing as they are diverse, ranging from degradation of molecules vital to innate immune mechanisms to subversion of the mechanisms to allow the bacterium to hide from the system or take advantage of it. It is vital that such mechanisms are elucidated to allow strategies to be developed to aid the innate immune system in controlling bacterial infections.

  10. Differential expression of the MERS-coronavirus receptor in the upper respiratory tract of humans and dromedary camels

    NARCIS (Netherlands)

    Widagdo, W; Raj, V Stalin; Schipper, Debby; Kolijn, Kimberley; van Leenders, Geert J L H; Bosch, Berend J; Bensaid, Albert; Segalés, Joaquim; Baumgärtner, Wolfgang; Osterhaus, Albert D M E; Koopmans, Marion P; van den Brand, Judith M A; Haagmans, Bart L

    Middle East respiratory syndrome coronavirus (MERS-CoV) is not efficiently transmitted between humans, but it is highly prevalent in dromedary camels. Here we report that the MERS-CoV receptor - dipeptidyl peptidase 4 (DPP4) - is expressed in the upper respiratory tract epithelium of camels but not

  11. Searching for animal models and potential target species for emerging pathogens: Experience gained from Middle East respiratory syndrome (MERS coronavirus

    Directory of Open Access Journals (Sweden)

    Júlia Vergara-Alert

    2017-06-01

    Full Text Available Emerging and re-emerging pathogens represent a substantial threat to public health, as demonstrated with numerous outbreaks over the past years, including the 2013–2016 outbreak of Ebola virus in western Africa. Coronaviruses are also a threat for humans, as evidenced in 2002/2003 with infection by the severe acute respiratory syndrome coronavirus (SARS-CoV, which caused more than 8000 human infections with 10% fatality rate in 37 countries. Ten years later, a novel human coronavirus (Middle East respiratory syndrome coronavirus, MERS-CoV, associated with severe pneumonia, arose in the Kingdom of Saudi Arabia. Until December 2016, MERS has accounted for more than 1800 cases and 35% fatality rate. Finding an animal model of disease is key to develop vaccines or antivirals against such emerging pathogens and to understand its pathogenesis. Knowledge of the potential role of domestic livestock and other animal species in the transmission of pathogens is of importance to understand the epidemiology of the disease. Little is known about MERS-CoV animal host range. In this paper, experimental data on potential hosts for MERS-CoV is reviewed. Advantages and limitations of different animal models are evaluated in relation to viral pathogenesis and transmission studies. Finally, the relevance of potential new target species is discussed.

  12. Middle east respiratory syndrome coronavirus spike protein delivered by modified vaccinia virus ankara efficiently induces virus-neutralizing antibodies

    NARCIS (Netherlands)

    F. Song (Fei); R. Fux (Robert); L.B.V. Provacia (Lisette); A. Volz (Asisa); M. Eickmann; S. Becker (Stephan); A.D.M.E. Osterhaus (Albert); B.L. Haagmans (Bart); G. Suttera (Gerd)

    2013-01-01

    textabstractMiddle East respiratory syndrome coronavirus (MERS-CoV) has recently emerged as a causative agent of severe respiratory disease in humans. Here, we constructed recombinant modified vaccinia virus Ankara (MVA) expressing full-length MERS-CoV spike (S) protein (MVA-MERS-S). The genetic

  13. Evaluation of bovine coronavirus antibody levels, virus shedding, and respiratory disease incidence throughout the beef cattle production cycle

    Science.gov (United States)

    Objective- Determine how levels of serum antibody to bovine coronavirus (BCV) are related to virus shedding patterns and respiratory disease incidence in beef calves at various production stages. Animals- 890 crossbred beef calves from four separately managed herds at the U.S. Meat Animal Research C...

  14. Clinico-epidemiological characteristics of acute respiratory infections caused by coronavirus OC43, NL63 and 229E.

    Science.gov (United States)

    Reina, J; López-Causapé, C; Rojo-Molinero, E; Rubio, R

    2014-12-01

    Acute respiratory infection is a very common condition in the general population. The majority of these infections are due to viruses. This study attempted to determine the clinical and epidemiological characteristics of adult patients with respiratory infection by the coronavirus OC43, NL63 and 229E. Between January 2013 and February 2014, we prospectively studied all patients with suspected clinical respiratory infection by taking throat swabs and performing a reverse transcription polymerase chain reaction in search of coronavirus. In 48 cases (7.0% of the 686 enrolled patients; 12.6% of the 381 in whom a virus was detected) the presence of a coronavirus demonstrated. In 24 cases, the virus was OC43 (50%); in 14 cases, the virus was NL63 (29%); and in 10 cases, the virus was 229E (21%). The mean age was 54.5 years, with a slight predominance of men. The most common clinical presentations were nonspecific influenza symptoms (43.7%), pneumonia (29.2%) and chronic obstructive pulmonary disease exacerbation (8.3%). Fifty-two percent of the patients required hospitalization, and 2 patients required intensive care. There were no deaths. Acute respiratory infections caused by coronavirus mainly affect middle-aged male smokers, who are often affected by previous diseases. The most common clinical picture has been nonspecific influenza symptoms. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

  15. Differential sensitivity of bat cells to infection by enveloped RNA viruses: coronaviruses, paramyxoviruses, filoviruses, and influenza viruses.

    Directory of Open Access Journals (Sweden)

    Markus Hoffmann

    Full Text Available Bats (Chiroptera host major human pathogenic viruses including corona-, paramyxo, rhabdo- and filoviruses. We analyzed six different cell lines from either Yinpterochiroptera (including African flying foxes and a rhinolophid bat or Yangochiroptera (genera Carollia and Tadarida for susceptibility to infection by different enveloped RNA viruses. None of the cells were sensitive to infection by transmissible gastroenteritis virus (TGEV, a porcine coronavirus, or to infection mediated by the Spike (S protein of SARS-coronavirus (SARS-CoV incorporated into pseudotypes based on vesicular stomatitis virus (VSV. The resistance to infection was overcome if cells were transfected to express the respective cellular receptor, porcine aminopeptidase N for TGEV or angiotensin-converting enzyme 2 for SARS-CoV. VSV pseudotypes containing the S proteins of two bat SARS-related CoV (Bg08 and Rp3 were unable to infect any of the six tested bat cell lines. By contrast, viral pseudotypes containing the surface protein GP of Marburg virus from the family Filoviridae infected all six cell lines though at different efficiency. Notably, all cells were sensitive to infection by two paramyxoviruses (Sendai virus and bovine respiratory syncytial virus and three influenza viruses from different subtypes. These results indicate that bat cells are more resistant to infection by coronaviruses than to infection by paramyxoviruses, filoviruses and influenza viruses. Furthermore, these results show a receptor-dependent restriction of the infection of bat cells by CoV. The implications for the isolation of coronaviruses from bats are discussed.

  16. Presence of Middle East respiratory syndrome coronavirus antibodies in Saudi Arabia : a nationwide, cross-sectional, serological study

    NARCIS (Netherlands)

    Müller, Marcel A; Meyer, Benjamin; Corman, Victor M; Al-Masri, Malak; Turkestani, Abdulhafeez; Ritz, Daniel; Sieberg, Andrea; Aldabbagh, Souhaib; Bosch, Berend-J; Lattwein, Erik; Alhakeem, Raafat F; Assiri, Abdullah M; Albarrak, Ali M; Al-Shangiti, Ali M; Al-Tawfiq, Jaffar A; Wikramaratna, Paul; Alrabeeah, Abdullah A; Drosten, Christian; Memish, Ziad A

    2015-01-01

    BACKGROUND: Scientific evidence suggests that dromedary camels are the intermediary host for the Middle East respiratory syndrome coronavirus (MERS-CoV). However, the actual number of infections in people who have had contact with camels is unknown and most index patients cannot recall any such

  17. Conserved antigenic sites between MERS-CoV and Bat-coronavirus are revealed through sequence analysis.

    Science.gov (United States)

    Sharmin, Refat; Islam, Abul B M M K

    2016-01-01

    MERS-CoV is a newly emerged human coronavirus reported closely related with HKU4 and HKU5 Bat coronaviruses. Bat and MERS corona-viruses are structurally related. Therefore, it is of interest to estimate the degree of conserved antigenic sites among them. It is of importance to elucidate the shared antigenic-sites and extent of conservation between them to understand the evolutionary dynamics of MERS-CoV. Multiple sequence alignment of the spike (S), membrane (M), enveloped (E) and nucleocapsid (N) proteins was employed to identify the sequence conservation among MERS and Bat (HKU4, HKU5) coronaviruses. We used various in silico tools to predict the conserved antigenic sites. We found that MERS-CoV shared 30 % of its S protein antigenic sites with HKU4 and 70 % with HKU5 bat-CoV. Whereas 100 % of its E, M and N protein's antigenic sites are found to be conserved with those in HKU4 and HKU5. This sharing suggests that in case of pathogenicity MERS-CoV is more closely related to HKU5 bat-CoV than HKU4 bat-CoV. The conserved epitopes indicates their evolutionary relationship and ancestry of pathogenicity.

  18. Assembly of spikes into coronavirus particles is mediated by the carboxy-terminal domain of the spike protein

    NARCIS (Netherlands)

    Godeke, G J; de Haan, Cornelis A M; Rossen, J W; Vennema, H; Rottier, P J

    The type I glycoprotein S of coronavirus, trimers of which constitute the typical viral spikes, is assembled into virions through noncovalent interactions with the M protein. Here we demonstrate that incorporation is mediated by the short carboxy-terminal segment comprising the transmembrane and

  19. Detection by radioimmunoassay and enzyme-linked immunosorbent assay of coronavirus antibodies in bovine serum and lacteal secretions.

    Science.gov (United States)

    Rodak, L; Babiuk, L A; Acres, S D

    1982-07-01

    The sensitivity of a radioimmunoassay (RIA), an enzyme-linked immunosorbent assay (ELISA), and a serum neutralization assay (SN) for detecting antibodies to bovine coronavirus in serum and colostrum were compared. Although there proved to be a good correlation among all three assays (r = 0.915 and 0.964 for RIA with SN and ELISA, respectively), RIA and ELISA proved to be at least 10 times more sensitive than neutralization tests. By using these techniques, it was possible to detect a time-dependent decrease in antibody levels in bovine colostrum after parturition. Using ELISA, we demonstrated that 12 of 12 herds in Saskatchewan, and 109 of 110 animals tested, and antibody to bovine coronavirus. There was no elevated antibody response in serum or lacteal secretions of cows vaccinated once or twice with a commercially available modified live rota-coronavirus vaccine. In addition to being more sensitive than SN, ELISA and RIA proved to have other advantages for measuring antibody levels to bovine coronavirus and therefore warrant wider use as tools in diagnostic virology.

  20. Isolation and characterization of current human coronavirus strains in primary human epithelial cell cultures reveal differences in target cell tropism

    NARCIS (Netherlands)

    Dijkman, Ronald; Jebbink, Maarten F.; Koekkoek, Sylvie M.; Deijs, Martin; Jónsdóttir, Hulda R.; Molenkamp, Richard; Ieven, Margareta; Goossens, Herman; Thiel, Volker; van der Hoek, Lia

    2013-01-01

    The human airway epithelium (HAE) represents the entry port of many human respiratory viruses, including human coronaviruses (HCoVs). Nowadays, four HCoVs, HCoV-229E, HCoV-OC43, HCoV-HKU1, and HCoV-NL63, are known to be circulating worldwide, causing upper and lower respiratory tract infections in

  1. Immune evasion of porcine enteric coronaviruses and viral modulation of antiviral innate signaling.

    Science.gov (United States)

    Zhang, Qingzhan; Yoo, Dongwan

    2016-12-02

    Porcine epidemic diarrhea virus (PEDV) and porcine deltacoronavirus (PDCoV) are emerged and reemerging viruses in pigs, and together with transmissible gastroenteritis virus (TGEV), pose significant economic concerns to the swine industry. These viruses infect epithelial cells of the small intestine and cause watery diarrhea, dehydration, and a high mortality in neonatal piglets. Type I interferons (IFN-α/β) are major antiviral cytokines forming host innate immunity, and in turn, these enteric coronaviruses have evolved to modulate the host innate immune signaling during infection. Accumulating evidence however suggests that IFN induction and signaling in the intestinal epithelial cells differ from other epithelial cells, largely due to distinct features of the gut epithelial mucosal surface and commensal microflora, and it appears that type III interferon (IFN-λ) plays a key role to maintain the antiviral state in the gut. This review describes the recent understanding on the immune evasion strategies of porcine enteric coronaviruses and the role of different types of IFNs for intestinal antiviral innate immunity. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Synthesis and processing of structural and intracellular proteins of two enteric coronaviruses

    International Nuclear Information System (INIS)

    Sardinia, L.M.

    1985-01-01

    The synthesis and processing of virus-specific proteins of two economically important enteric coronaviruses, bovine enteric coronavirus (BCV) and transmissible gastroenteritis virus (TGEV), were studied at the molecular level. To determine the time of appearance of virus-specific proteins, virus-infected cells were labeled with 35 S-methionine at various times during infection, immunoprecipitated with specific hyperimmune ascitic fluid, and analyzed by SDS-polyacrylamide gel electrophoresis. The peak of BCV protein synthesis was found to be at 12 hours postinfection (hpi). The appearance of all virus-specific protein was coordinated. In contrast, the peak of TGEV protein synthesis was at 8 hpi, but the nucleocapsid proteins was present as early as 4 hpi. Virus-infected cells were treated with tunicamycin to ascertain the types of glycosidic linkages of the glycoproteins. The peplomer proteins of both viruses were sensitive to inhibition by tunicamycin indicating that they possessed N-linked carbohydrates. The matrix protein of TGEV was similarly affected. The matrix protein of BCV, however, was resistant to tunicamycin treatment and, therefore, has O-linked carbohydrates. Only the nucleocapsid protein of both viruses is phosphorylated as detected by radiolabeling with 32 P-orthophosphate. Pulse-chase studies and comparison of intracellular and virion proteins were done to detect precursor-product relationships

  3. Biochemical and biophysical characterization of the transmissible gastroenteritis coronavirus fusion core

    International Nuclear Information System (INIS)

    Ma Guangpeng; Feng Youjun; Gao Feng; Wang Jinzi; Liu Cheng; Li Yijing

    2005-01-01

    Transmissible gastroenteritis coronavirus (TGEV) is one of the most destructive agents, responsible for the enteric infections that are lethal for suckling piglets, causing enormous economic loss to the porcine fostering industry every year. Although it has been known that TGEV spiker protein is essential for the viral entry for many years, the detail knowledge of the TGEV fusion protein core is still very limited. Here, we report that TGEV fusion core (HR1-SGGRGG-HR2), in vitro expressed in GST prokaryotic expression system, shares the typical properties of the trimer of coiled-coil heterodimer (six α-helix bundle), which has been confirmed by a combined series of biochemical and biophysical evidences including size exclusion chromatography (gel-filtration), chemical crossing, and circular diagram. The 3D homologous structure model presents its most likely structure, extremely similar to those of the coronaviruses documented. Taken together, TGEV spiker protein belongs to the class I fusion protein, characterized by the existence of two heptad-repeat (HR) regions, HR1 and HR2, and the present knowledge about the truncated TGEV fusion protein core may facilitate in the design of the small molecule or polypeptide drugs targeting the membrane fusion between TGEV and its host

  4. Novel coronaviruses, astroviruses, adenoviruses and circoviruses in insectivorous bats from northern China.

    Science.gov (United States)

    Han, H-J; Wen, H-L; Zhao, L; Liu, J-W; Luo, L-M; Zhou, C-M; Qin, X-R; Zhu, Y-L; Liu, M-M; Qi, R; Li, W-Q; Yu, H; Yu, X-J

    2017-12-01

    Bats are considered as the reservoirs of several emerging infectious disease, and novel viruses are continually found in bats all around the world. Studies conducted in southern China found that bats carried a variety of viruses. However, few studies have been conducted on bats in northern China, which harbours a diversity of endemic insectivorous bats. It is important to understand the prevalence and diversity of viruses circulating in bats in northern China. In this study, a total of 145 insectivorous bats representing six species were collected from northern China and screened with degenerate primers for viruses belonging to six families, including coronaviruses, astroviruses, hantaviruses, paramyxoviruses, adenoviruses and circoviruses. Our study found that four of the viruses screened for were positive and the overall detection rates for astroviruses, coronaviruses, adenoviruses and circoviruses in bats were 21.4%, 15.9%, 20% and 37.2%, respectively. In addition, we found that bats in northern China harboured a diversity of novel viruses. Common Serotine (Eptesicus serotinu), Fringed long-footed Myotis (Myotis fimriatus) and Peking Myotis (Myotis pequinius) were investigated in China for the first time. Our study provided new information on the ecology and phylogeny of bat-borne viruses. © 2017 The Authors. Zoonoses and Public Health Published by Blackwell Verlag GmbH.

  5. A mouse model for MERS coronavirus-induced acute respiratory distress syndrome.

    Science.gov (United States)

    Cockrell, Adam S; Yount, Boyd L; Scobey, Trevor; Jensen, Kara; Douglas, Madeline; Beall, Anne; Tang, Xian-Chun; Marasco, Wayne A; Heise, Mark T; Baric, Ralph S

    2016-11-28

    Middle East respiratory syndrome coronavirus (MERS-CoV) is a novel virus that emerged in 2012, causing acute respiratory distress syndrome (ARDS), severe pneumonia-like symptoms and multi-organ failure, with a case fatality rate of ∼36%. Limited clinical studies indicate that humans infected with MERS-CoV exhibit pathology consistent with the late stages of ARDS, which is reminiscent of the disease observed in patients infected with severe acute respiratory syndrome coronavirus. Models of MERS-CoV-induced severe respiratory disease have been difficult to achieve, and small-animal models traditionally used to investigate viral pathogenesis (mouse, hamster, guinea-pig and ferret) are naturally resistant to MERS-CoV. Therefore, we used CRISPR-Cas9 gene editing to modify the mouse genome to encode two amino acids (positions 288 and 330) that match the human sequence in the dipeptidyl peptidase 4 receptor, making mice susceptible to MERS-CoV infection and replication. Serial MERS-CoV passage in these engineered mice was then used to generate a mouse-adapted virus that replicated efficiently within the lungs and evoked symptoms indicative of severe ARDS, including decreased survival, extreme weight loss, decreased pulmonary function, pulmonary haemorrhage and pathological signs indicative of end-stage lung disease. Importantly, therapeutic countermeasures comprising MERS-CoV neutralizing antibody treatment or a MERS-CoV spike protein vaccine protected the engineered mice against MERS-CoV-induced ARDS.

  6. The effect of inhibition of PP1 and TNFα signaling on pathogenesis of SARS coronavirus

    Energy Technology Data Exchange (ETDEWEB)

    McDermott, Jason E.; Mitchell, Hugh D.; Gralinski, Lisa E.; Eisfeld, Amie J.; Josset, Laurence; Bankhead, Armand; Neumann, Gabriele; Tilton, Susan C.; Schäfer, Alexandra; Li, Chengjun; Fan, Shufang; McWeeney, Shannon; Baric, Ralph S.; Katze, Michael G.; Waters, Katrina M.

    2016-09-23

    The complex interplay between viral replication and host immune response during infection remains poorly understood. While many viruses are known to employ antiimmune strategies to facilitate their replication, highly pathogenic virus infections can also cause an excessive immune response that exacerbates, rather than reduces pathogenicity. To investigate this dichotomy in severe acute respiratory syndrome coronavirus (SARS-CoV), we developed a transcriptional network model of SARS-CoV infection in mice and used the model to prioritize candidate regulatory targets for further investigation. We validated our predictions in 18 different knockout (KO) mouse strains, showing that network topology provides significant predictive power to identify genes that are important for viral infection. We identified a novel player in the immune response to virus infection, Kepi, an inhibitory subunit of the protein phosphatase 1 (PP1) complex, which protects against SARS-CoV pathogenesis. We also found that receptors for the proinflammatory cytokine, tumor necrosis factor alpha (TNFα), promote pathogenesis through a parallel feed-forward circuit that promotes inflammation. These results are consistent with previous studies showing the role of over-stimulation of the inflammatory response to SARS-CoV in pathogenesis. We conclude that the critical balance between immune response and inflammation can be manipulated to improve the outcome of the infection. Further, our study provides two potential therapeutic strategies for mitigating the effects of SARS-CoV infection, and may provide insight into treatment strategies for Middle East Respiratory Syndrome Coronavirus (MERS-CoV).

  7. Survey of feline leukemia virus and feline coronaviruses in captive neotropical wild felids from Southern Brazil.

    Science.gov (United States)

    Guimaraes, Ana M S; Brandão, Paulo E; de Moraes, Wanderlei; Cubas, Zalmir S; Santos, Leonilda C; Villarreal, Laura Y B; Robes, Rogério R; Coelho, Fabiana M; Resende, Mauricio; Santos, Renata C F; Oliveira, Rosangela C; Yamaguti, Mauricio; Marques, Lucas M; Neto, Renata L; Buzinhani, Melissa; Marques, Regina; Messick, Joanne B; Biondo, Alexander W; Timenetsky, Jorge

    2009-06-01

    A total of 57 captive neotropical felids (one Leopardus geoffroyi, 14 Leopardus pardalis, 17 Leopardus wiedii, 22 Leopardus tigrinus, and three Puma yagouaroundi) from the Itaipu Binacional Wildlife Research Center (Refúgio Bela Vista, Southern Brazil) were anesthetized for blood collection. Feces samples were available for 44 animals, including one L. geoffroyi, eight L. pardalis, 14 L. wiedii, 20 L. tigrinus, and one P. yagouaroundi. Total DNA and RNA were extracted from blood and feces, respectively, using commercial kits. Blood DNA samples were evaluated by polymerase chain reaction (PCR) for feline leukemia virus (FeLV) proviral DNA, whereas reverse transcriptase-PCR was run on fecal samples for detection of coronavirus RNA. None of the samples were positive for coronaviruses. A male L. pardalis and a female L. tigrinus were positive for FeLV proviral DNA, and identities of PCR products were confirmed by sequencing. This is the first evidence of FeLV proviral DNA in these species in Southern Brazil.

  8. Mutation of the S and 3c genes in genomes of feline coronaviruses.

    Science.gov (United States)

    Oguma, Keisuke; Ohno, Megumi; Yoshida, Mayuko; Sentsui, Hiroshi

    2018-05-17

    Feline coronavirus (FCoV) is classified into two biotypes based on its pathogenicity in cats: a feline enteric coronavirus of low pathogenicity and a highly virulent feline infectious peritonitis virus. It has been suspected that FCoV alters its biotype via mutations in the viral genome. The S and 3c genes of FCoV have been considered the candidates for viral pathogenicity conversion. In the present study, FCoVs were analyzed for the frequency and location of mutations in the S and 3c genes from faecal samples of cats in an animal shelter and the faeces, effusions, and tissues of cats that were referred to veterinary hospitals. Our results indicated that approximately 95% FCoVs in faeces did not carry mutations in the two genes. However, 80% FCoVs in effusion samples exhibited mutations in the S and 3c genes with remainder displaying a mutation in the S or 3c gene. It was also suggested that mutational analysis of the 3c gene could be useful for studying the horizontal transmission of FCoVs in multi-cat environments.

  9. Erwinia carotovora extracellular proteases : characterization and role in soft rot

    OpenAIRE

    Kyöstiö, Sirkka R. M.

    1990-01-01

    Erwinia carotovora subsp. carotovora (Ecc) strain EC14, a Gram-negative bacterium, causes soft rot on several crops, including potato. Maceration of potato tuber tissue is caused by secreted pectolytic enzymes. Other cell-degrading enzymes may also have roles in pathogenesis, including cellulases, phospholipases, and protease(s). The objectives of this research were to (1) characterize Ecc extracellular protease (Prt) and (2) elucidate its role in potato soft rot. A gene enc...

  10. Economic Methods of Ginger Protease'sextraction and Purification

    Science.gov (United States)

    Qiao, Yuanyuan; Tong, Junfeng; Wei, Siqing; Du, Xinyong; Tang, Xiaozhen

    This article reports the ginger protease extraction and purification methods from fresh ginger rhizome. As to ginger protease extraction, we adapt the steps of organic solvent dissolving, ammonium sulfate depositing and freeze-drying, and this method can attain crude enzyme powder 0.6% weight of fresh ginger rhizome. The purification part in this study includes two steps: cellulose ion exchange (DEAE-52) and SP-Sephadex 50 chromatography, which can purify crude ginger protease through ion and molecular weight differences respectively.

  11. Indispensable Role of Proteases in Plant Innate Immunity.

    Science.gov (United States)

    Balakireva, Anastasia V; Zamyatnin, Andrey A

    2018-02-23

    Plant defense is achieved mainly through the induction of microbe-associated molecular patterns (MAMP)-triggered immunity (MTI), effector-triggered immunity (ETI), systemic acquired resistance (SAR), induced systemic resistance (ISR), and RNA silencing. Plant immunity is a highly complex phenomenon with its own unique features that have emerged as a result of the arms race between plants and pathogens. However, the regulation of these processes is the same for all living organisms, including plants, and is controlled by proteases. Different families of plant proteases are involved in every type of immunity: some of the proteases that are covered in this review participate in MTI, affecting stomatal closure and callose deposition. A large number of proteases act in the apoplast, contributing to ETI by managing extracellular defense. A vast majority of the endogenous proteases discussed in this review are associated with the programmed cell death (PCD) of the infected cells and exhibit caspase-like activities. The synthesis of signal molecules, such as salicylic acid, jasmonic acid, and ethylene, and their signaling pathways, are regulated by endogenous proteases that affect the induction of pathogenesis-related genes and SAR or ISR establishment. A number of proteases are associated with herbivore defense. In this review, we summarize the data concerning identified plant endogenous proteases, their effect on plant-pathogen interactions, their subcellular localization, and their functional properties, if available, and we attribute a role in the different types and stages of innate immunity for each of the proteases covered.

  12. Heterologous expression of Hordeum vulgare cysteine protease in yeast

    DEFF Research Database (Denmark)

    Rosenkilde, Anne Lind; Dionisio, Giuseppe; Holm, Preben B

    Cysteine Proteases accounts for more than 90 % of the total proteolytic activity in the degradation of barley seed storage proteins during germination. Several Cysteine proteases have been identified in barley. One of the key enzymes, Hordeum vulgare endoprotease B2 (HvEPB2) was cloned with and w......Cysteine Proteases accounts for more than 90 % of the total proteolytic activity in the degradation of barley seed storage proteins during germination. Several Cysteine proteases have been identified in barley. One of the key enzymes, Hordeum vulgare endoprotease B2 (HvEPB2) was cloned...

  13. Expression and Characterization of Coprothermobacter proteolyticus Alkaline Serine Protease

    Directory of Open Access Journals (Sweden)

    Tanveer Majeed

    2013-01-01

    Full Text Available A putative protease gene (aprE from the thermophilic bacterium Coprothermobacter proteolyticus was cloned and expressed in Bacillus subtilis. The enzyme was determined to be a serine protease based on inhibition by PMSF. Biochemical characterization demonstrated that the enzyme had optimal activity under alkaline conditions (pH 8–10. In addition, the enzyme had an elevated optimum temperature (60°C. The protease was also stable in the presence of many surfactants and oxidant. Thus, the C. proteolyticus protease has potential applications in industries such as the detergent market.

  14. Characterization of Fibrinolytic Proteases from Gloydius blomhoffii siniticus Venom

    Directory of Open Access Journals (Sweden)

    Suk Ho Choi

    2011-09-01

    Full Text Available Objectives : This study was undertaken to identify fibrinolytic proteases from Gloydius blomhoffii siniticus venom and to characterize a major fibrinolytic protease purified from the venom. Methods: The venom was subjected to chromatography using columns of Q-Sepharose and Sephadex G-75. The molecular weights of fibrinolytic proteases showing fibrinolytic zone in fibrin plate assay were determined in SDS-PAGE (Sodium dodecyl sulfate-polyacrylamide gel electrophoresis The effects of inhibitors and metal ions on fibrinolytic protease and the proteolysis patterns of fibrinogen, gelatin, and bovine serum albumin were investigated. Results : 1 The fibrinolytic fractions of the three peaks isolated from Gloydius blomhoffii siniticus venom contained two polypeptides of 46 and 59 kDa and three polypeptides of 32, 18, and 15 kDa and a major polypeptide of 54 kDa, respectively. 2 The fibrinolytic activity of the purified protease of 54 kDA was inhibited by metal chelators, such as EDTA, EGTA, and 1,10-phenanthroline, and disulfhydryl-reducing compounds, such as dithiothreitol and cysteine. 3 Calcium chloride promoted the fibrinolytic activity of the protease, but mercuric chloride and cobalt(II chloride inhibited it. 4 The fibrinolytic protease cleaved preferentially A-chain and slowly B-chain of fibrinogen. It also hydrolyzed gelatin but not bovine serum albumin. Conclusions: The Gloydius blomhoffii siniticus venom contained more than three fibrinolytic proteases. The major fibrinolytic protease was a metalloprotease which hydrolyzed both fibrinogen and gelatin, but not bovine serum albumin.

  15. Fibrin(ogen)olytic activity of bumblebee venom serine protease

    International Nuclear Information System (INIS)

    Qiu Yuling; Choo, Young Moo; Yoon, Hyung Joo; Jia Jingming; Cui Zheng; Wang Dong; Kim, Doh Hoon; Sohn, Hung Dae; Jin, Byung Rae

    2011-01-01

    Bee venom is a rich source of pharmacologically active components; it has been used as an immunotherapy to treat bee venom hypersensitivity, and venom therapy has been applied as an alternative medicine. Here, we present evidence that the serine protease found in bumblebee venom exhibits fibrin(ogen)olytic activity. Compared to honeybee venom, bumblebee venom contains a higher content of serine protease, which is one of its major components. Venom serine proteases from bumblebees did not cross-react with antibodies against the honeybee venom serine protease. We provide functional evidence indicating that bumblebee (Bombus terrestris) venom serine protease (Bt-VSP) acts as a fibrin(ogen)olytic enzyme. Bt-VSP activates prothrombin and directly degrades fibrinogen into fibrin degradation products. However, Bt-VSP is not a plasminogen activator, and its fibrinolytic activity is less than that of plasmin. Taken together, our results define roles for Bt-VSP as a prothrombin activator, a thrombin-like protease, and a plasmin-like protease. These findings offer significant insight into the allergic reaction sequence that is initiated by bee venom serine protease and its potential usefulness as a clinical agent in the field of hemostasis and thrombosis. - Graphical abstract: Display Omitted Highlights: → Bumblebee venom serine protease (Bt-VSP) is a fibrin(ogen)olytic enzyme. → Bt-VSP activates prothrombin. → Bt-VSP directly degrades fibrinogen into fibrin degradation products. → Bt-VSP is a hemostatically active protein that is a potent clinical agent.

  16. Severe Acute Respiratory Syndrome-Coronavirus Papain-Like Novel Protease Inhibitors: Design, Synthesis, Protein-Ligand X-ray Structure and Biological Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Arun K.; Takayama, Jun; Rao, Kalapala Venkateswar; Ratia, Kiira; Chaudhuri, Rima; Mulhearn, Debbie C.; Lee, Hyun; Nichols, Daniel B.; Baliji, Surendranath; Baker, Susan C.; Johnson, Michael E.; Mesecar, Andrew D. (Purdue); (UC); (UIC)

    2012-02-21

    The design, synthesis, X-ray crystal structure, molecular modeling, and biological evaluation of a series of new generation SARS-CoV PLpro inhibitors are described. A new lead compound 3 (6577871) was identified via high-throughput screening of a diverse chemical library. Subsequently, we carried out lead optimization and structure-activity studies to provide a series of improved inhibitors that show potent PLpro inhibition and antiviral activity against SARS-CoV infected Vero E6 cells. Interestingly, the (S)-Me inhibitor 15h (enzyme IC{sub 50} = 0.56 {mu}M; antiviral EC{sub 50} = 9.1 {mu}M) and the corresponding (R)-Me 15g (IC{sub 50} = 0.32 {mu}M; antiviral EC{sub 50} = 9.1 {mu}M) are the most potent compounds in this series, with nearly equivalent enzymatic inhibition and antiviral activity. A protein-ligand X-ray structure of 15g-bound SARS-CoV PLpro and a corresponding model of 15h docked to PLpro provide intriguing molecular insight into the ligand-binding site interactions.

  17. Intracellular alkaline proteases produced by thermoacidophiles: detection of protease heterogeneity by gelatin zymography and polymerase chain reaction (PCR)

    Energy Technology Data Exchange (ETDEWEB)

    Kocab, S.; Erdem, B. [Middle East Technical University, Ankara (Turkey). Dept. of Biological Sciences

    2002-08-01

    In this study 24 thermoacidophilic archeal and bacterial strains isolated from hot-springs and hot-soils were screened for their ability to produce intracellular alkaline proteases. The protease activities of the strains, based on azocasein hydrolysis, showed a variation from 0.6 to 5.1 U. The cell extracts of three most potent producers were further examined and it was found that their proteases exhibited maximum activity at 60-70{sup o}C and showed a pH optimum over a range of pH 7.0-8.5. Gelatin zymography revealed that two of the selected archeal strains produced multiple active SDS-resistant proteases. On the other hand, PCR amplification of alkaline serine protease gene sequences of total DNA from all isolates yielded four distinct amplification fragments of 650, 450, 400 and 300 bp, which might have been derived from different serine protease genes. (author)

  18. Altered pathogenesis of porcine respiratory coronavirus in pigs due to immunosuppressive effects of dexamethasone: implications for corticosteroid use in treatment of severe acute respiratory syndrome coronavirus.

    Science.gov (United States)

    Jung, Kwonil; Alekseev, Konstantin P; Zhang, Xinsheng; Cheon, Doo-Sung; Vlasova, Anastasia N; Saif, Linda J

    2007-12-01

    The pathogenesis and optimal treatments for severe acute respiratory syndrome (SARS) are unclear, although corticosteroids were used to reduce lung and systemic inflammation. Because the pulmonary pathology of porcine respiratory coronavirus (PRCV) in pigs resembles SARS, we used PRCV as a model to clarify the effects of the corticosteroid dexamethasone (DEX) on coronavirus (CoV)-induced pneumonia. Conventional weaned pigs (n = 130) in one of four groups (PRCV/phosphate-buffered saline [PBS] [n = 41], PRCV/DEX [n = 41], mock/PBS [n = 23], and mock/DEX [n = 25]) were inoculated intranasally and intratracheally with the ISU-1 strain of PRCV (1 x 10(7) PFU) or cell culture medium. DEX was administered (once daily, 2 mg/kg of body weight/day, intramuscularly) from postinoculation day (PID) 1 to 6. In PRCV/DEX pigs, significantly milder pneumonia, fewer PRCV-positive cells, and lower viral RNA titers were present in lungs early at PID 2; however, at PID 4, 10, and 21, severe bronchointerstitial pneumonia, significantly higher numbers of PRCV-positive cells, and higher viral RNA titers were observed compared to results for PRCV/PBS pigs. Significantly lower numbers of CD2(+), CD3(+), CD4(+), and CD8(+) T cells were also observed in lungs of PRCV/DEX pigs than in those of PRCV/PBS pigs at PID 8 and 10, coincident with fewer gamma interferon (IFN-gamma)-secreting cells in the tracheobronchial lymph nodes as determined by enzyme-linked immunospot assay. Our results confirm that DEX treatment alleviates PRCV pneumonia early (PID 2) in the infection but continued use through PID 6 exacerbates later stages of infection (PID 4, 10, and 21), possibly by decreasing cellular immune responses in the lungs (IFN-gamma-secreting T cells), thereby creating an environment for more-extensive viral replication. These data have potential implications for corticosteroid use with SARS-CoV patients and suggest a precaution against prolonged use based on their unproven efficacy in humans

  19. Reversible Unfolding of Rhomboid Intramembrane Proteases.

    Science.gov (United States)

    Panigrahi, Rashmi; Arutyunova, Elena; Panwar, Pankaj; Gimpl, Katharina; Keller, Sandro; Lemieux, M Joanne

    2016-03-29

    Denaturant-induced unfolding of helical membrane proteins provides insights into their mechanism of folding and domain organization, which take place in the chemically heterogeneous, anisotropic environment of a lipid membrane. Rhomboid proteases are intramembrane proteases that play key roles in various diseases. Crystal structures have revealed a compact helical bundle with a buried active site, which requires conformational changes for the cleavage of transmembrane substrates. A dimeric form of the rhomboid protease has been shown to be important for activity. In this study, we examine the mechanism of refolding for two distinct rhomboids to gain insight into their secondary structure-activity relationships. Although helicity is largely abolished in the unfolded states of both proteins, unfolding is completely reversible for HiGlpG but only partially reversible for PsAarA. Refolding of both proteins results in reassociation of the dimer, with a 90% regain of catalytic activity for HiGlpG but only a 70% regain for PsAarA. For both proteins, a broad, gradual transition from the native, folded state to the denatured, partly unfolded state was revealed with the aid of circular dichroism spectroscopy as a function of denaturant concentration, thus arguing against a classical two-state model as found for many globular soluble proteins. Thermal denaturation has irreversible destabilizing effects on both proteins, yet reveals important functional details regarding substrate accessibility to the buried active site. This concerted biophysical and functional analysis demonstrates that HiGlpG, with a simple six-transmembrane-segment organization, is more robust than PsAarA, which has seven predicted transmembrane segments, thus rendering HiGlpG amenable to in vitro studies of membrane-protein folding. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  20. Altered Pathogenesis of Porcine Respiratory Coronavirus in Pigs due to Immunosuppressive Effects of Dexamethasone: Implications for Corticosteroid Use in Treatment of Severe Acute Respiratory Syndrome Coronavirus▿

    OpenAIRE

    Jung, Kwonil; Alekseev, Konstantin P.; Zhang, Xinsheng; Cheon, Doo-Sung; Vlasova, Anastasia N.; Saif, Linda J.

    2007-01-01

    The pathogenesis and optimal treatments for severe acute respiratory syndrome (SARS) are unclear, although corticosteroids were used to reduce lung and systemic inflammation. Because the pulmonary pathology of porcine respiratory coronavirus (PRCV) in pigs resembles SARS, we used PRCV as a model to clarify the effects of the corticosteroid dexamethasone (DEX) on coronavirus (CoV)-induced pneumonia. Conventional weaned pigs (n = 130) in one of four groups (PRCV/phosphate-buffered saline [PBS] ...

  1. Structure of protease-cleaved Escherichia coli α-2-macroglobulin reveals a putative mechanism of conformational activation for protease entrapment

    Energy Technology Data Exchange (ETDEWEB)

    Fyfe, Cameron D.; Grinter, Rhys; Josts, Inokentijs; Mosbahi, Khedidja [University of Glasgow, Glasgow G12 8QQ, Scotland (United Kingdom); Roszak, Aleksander W. [University of Glasgow, Glasgow G12 8QQ, Scotland (United Kingdom); University of Glasgow, Glasgow G12 8QQ, Scotland (United Kingdom); Cogdell, Richard J.; Wall, Daniel M.; Burchmore, Richard J. S.; Byron, Olwyn; Walker, Daniel, E-mail: daniel.walker@glasgow.ac.uk [University of Glasgow, Glasgow G12 8QQ, Scotland (United Kingdom)

    2015-06-30

    The X-ray structure of protease-cleaved E. coli α-2-macroglobulin is described, which reveals a putative mechanism of activation and conformational change essential for protease inhibition. Bacterial α-2-macroglobulins have been suggested to function in defence as broad-spectrum inhibitors of host proteases that breach the outer membrane. Here, the X-ray structure of protease-cleaved Escherichia coli α-2-macroglobulin is described, which reveals a putative mechanism of activation and conformational change essential for protease inhibition. In this competitive mechanism, protease cleavage of the bait-region domain results in the untethering of an intrinsically disordered region of this domain which disrupts native interdomain interactions that maintain E. coli α-2-macroglobulin in the inactivated form. The resulting global conformational change results in entrapment of the protease and activation of the thioester bond that covalently links to the attacking protease. Owing to the similarity in structure and domain architecture of Escherichia coli α-2-macroglobulin and human α-2-macroglobulin, this protease-activation mechanism is likely to operate across the diverse members of this group.

  2. Structure of protease-cleaved Escherichia coli α-2-macroglobulin reveals a putative mechanism of conformational activation for protease entrapment

    International Nuclear Information System (INIS)

    Fyfe, Cameron D.; Grinter, Rhys; Josts, Inokentijs; Mosbahi, Khedidja; Roszak, Aleksander W.; Cogdell, Richard J.; Wall, Daniel M.; Burchmore, Richard J. S.; Byron, Olwyn; Walker, Daniel

    2015-01-01

    The X-ray structure of protease-cleaved E. coli α-2-macroglobulin is described, which reveals a putative mechanism of activation and conformational change essential for protease inhibition. Bacterial α-2-macroglobulins have been suggested to function in defence as broad-spectrum inhibitors of host proteases that breach the outer membrane. Here, the X-ray structure of protease-cleaved Escherichia coli α-2-macroglobulin is described, which reveals a putative mechanism of activation and conformational change essential for protease inhibition. In this competitive mechanism, protease cleavage of the bait-region domain results in the untethering of an intrinsically disordered region of this domain which disrupts native interdomain interactions that maintain E. coli α-2-macroglobulin in the inactivated form. The resulting global conformational change results in entrapment of the protease and activation of the thioester bond that covalently links to the attacking protease. Owing to the similarity in structure and domain architecture of Escherichia coli α-2-macroglobulin and human α-2-macroglobulin, this protease-activation mechanism is likely to operate across the diverse members of this group

  3. Construction of dengue virus protease expression plasmid and in vitro protease assay for screening antiviral inhibitors.

    Science.gov (United States)

    Lai, Huiguo; Teramoto, Tadahisa; Padmanabhan, Radhakrishnan

    2014-01-01

    Dengue virus serotypes 1-4 (DENV1-4) are mosquito-borne human pathogens of global significance causing ~390 million cases annually worldwide. The virus infections cause in general a self-limiting disease, known as dengue fever, but occasionally also more severe forms, especially during secondary infections, dengue hemorrhagic fever and dengue shock syndrome causing ~25,000 deaths annually. The DENV genome contains a single-strand positive sense RNA, approximately 11 kb in length. The 5'-end has a type I cap structure. The 3'-end has no poly(A) tail. The viral RNA has a single long open reading frame that is translated by the host translational machinery to yield a polyprotein precursor. Processing of the polyprotein precursor occurs co-translationally by cellular proteases and posttranslationally by the viral serine protease in the endoplasmic reticulum (ER) to yield three structural proteins (capsid (C), precursor membrane (prM), and envelope (E) and seven nonstructural (NS) proteins (NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5). The active viral protease consists of both NS2B, an integral membrane protein in the ER, and the N-terminal part of NS3 (180 amino acid residues) that contains the trypsin-like serine protease domain having a catalytic triad of H51, D75, and S135. The C-terminal part of NS3, ~170-618 amino acid residues, encodes an NTPase/RNA helicase and 5'-RNA triphosphatase activities; the latter enzyme is required for the first step in 5'-capping. The cleavage sites of the polyprotein by the viral protease consist of two basic amino acid residues such as KR, RR, or QR, followed by short chain amino acid residues, G, S, or T. Since the cleavage of the polyprotein by the viral protease is absolutely required for assembly of the viral replicase, blockage of NS2B/NS3pro activity provides an effective means for designing dengue virus (DENV) small-molecule therapeutics. Here we describe the screening of small-molecule inhibitors against DENV2 protease.

  4. Complexity of cancer protease biology: Cathepsin K expression and function in cancer progression

    NARCIS (Netherlands)

    Verbovšek, Urška; van Noorden, Cornelis J. F.; Lah, Tamara T.

    2015-01-01

    Proteases, including lysosomal cathepsins, are functionally involved in many processes in cancer progression from its initiation to invasion and metastatic spread. Only recently, cathepsin K (CatK), the cysteine protease originally reported as a collagenolytic protease produced by osteoclasts,

  5. HIV-1 protease-substrate coevolution in nelfinavir resistance.

    Science.gov (United States)

    Kolli, Madhavi; Ozen, Ayşegül; Kurt-Yilmaz, Nese; Schiffer, Celia A

    2014-07-01

    Resistance to various human immunodeficiency virus type 1 (HIV-1) protease inhibitors (PIs) challenges the effectiveness of therapies in treating HIV-1-infected individuals and AIDS patients. The virus accumulates mutations within the protease (PR) that render the PIs less potent. Occasionally, Gag sequences also coevolve with mutations at PR cleavage sites contributing to drug resistance. In this study, we investigated the structural basis of coevolution of the p1-p6 cleavage site with the nelfinavir (NFV) resistance D30N/N88D protease mutations by determining crystal structures of wild-type and NFV-resistant HIV-1 protease in complex with p1-p6 substrate peptide variants with L449F and/or S451N. Alterations of residue 30's interaction with the substrate are compensated by the coevolving L449F and S451N cleavage site mutations. This interdependency in the PR-p1-p6 interactions enhances intermolecular contacts and reinforces the overall fit of the substrate within the substrate envelope, likely enabling coevolution to sustain substrate recognition and cleavage in the presence of PR resistance mutations. Resistance to human immunodeficiency virus type 1 (HIV-1) protease inhibitors challenges the effectiveness of therapies in treating HIV-1-infected individuals and AIDS patients. Mutations in HIV-1 protease selected under the pressure of protease inhibitors render the inhibitors less potent. Occasionally, Gag sequences also mutate and coevolve with protease, contributing to maintenance of viral fitness and to drug resistance. In this study, we investigated the structural basis of coevolution at the Gag p1-p6 cleavage site with the nelfinavir (NFV) resistance D30N/N88D protease mutations. Our structural analysis reveals the interdependency of protease-substrate interactions and how coevolution may restore substrate recognition and cleavage in the presence of protease drug resistance mutations. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  6. Mechanisms and cellular functions of intramembrane proteases.

    Science.gov (United States)

    Urban, Siniša

    2013-12-01

    The turn of the millennium coincided with the branding of a fundamentally different class of enzyme - proteases that reside immersed inside the membrane. This new field was the convergence of completely separate lines of research focused on cholesterol homeostasis, Alzheimer's disease, and developmental genetics. None intended their ultimate path, but soon became a richly-integrated fabric for an entirely new field: regulated intramembrane proteolysis. Our aim in this Special Issue is to focus on the ancient and nearly ubiquitous enzymes that catalyze this unexpected yet important reaction. The pace of progress has been dramatic, resulting in a rapidly-expanding universe of known cellular functions, and a paradigm shift in the biochemical understanding of these once heretical enzymes. More recently, the first therapeutic successes have been attained by targeting an intramembrane protease. We consider these advances and identify oncoming opportunities in four parts: growing spectra of cellular roles, insights into biochemical mechanisms, therapeutic strategies, and newly-emerging topics. Recent studies also expose challenges for the future, including non-linear relationships between substrate identification and physiological functions, and the need for potent and specific, not broad-class, inhibitors. © 2013.

  7. Comparison of protease production from newly isolated bacterial ...

    African Journals Online (AJOL)

    Nasir

    2016-10-12

    Oct 12, 2016 ... Protease has gained a very important position in many industries such as food, pharmaceutical, chemical and leather industries. In this research, protease was obtained from bacteria. The bacterial strain was obtained from soil which was collected from different areas of Lahore, Pakistan. Fermentation ...

  8. Oxidative Stress: Promoter of Allergic Sensitization to Protease Allergens?

    NARCIS (Netherlands)

    van Rijt, Leonie S.; Utsch, Lara; Lutter, René; van Ree, Ronald

    2017-01-01

    Allergies arise from aberrant T helper type 2 responses to allergens. Several respiratory allergens possess proteolytic activity, which has been recognized to act as an adjuvant for the development of a Th2 response. Allergen source-derived proteases can activate the protease-activated receptor-2,

  9. Alkaline protease production on date waste by an alkalophilic ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-16

    May 16, 2008 ... After 72 h incubation in a shaker incubator ... different incubation times (0 to 72 h) were investigated. Alkaline .... of alkaline protease (75%) and 24% of total protein is precipitated. ... starches and wheat flour as carbon source on protease production .... JP 395, method of making and detergent composition.

  10. Extracellular protease produced by Bacillus subtilis isolated from ...

    African Journals Online (AJOL)

    In a study to evaluate the microbiological safety of some paracetamol oral solutions sold in some Nigerian drug stores, 40.0% of the samples examined was contaminated with protease-producing Bacillus subtilis. The production of extracellular protease was induced by casein in the minimal medium and was found to be the ...

  11. Isolation of alkaline protease from Bacillus subtilis AKRS3

    African Journals Online (AJOL)

    ashok

    2012-08-28

    Aug 28, 2012 ... production proved high protease production than the other tested ... Crude alkaline protease was most active at 55°C, pH 9 with casein as ... 13416 Afr. J. Biotechnol. ... The Gram-positive, aerobic, rod-shaped endospore-.

  12. Model building of a thermolysin-like protease by mutagenesis

    NARCIS (Netherlands)

    Frigerio, F; Margarit, [No Value; Nogarotto, R; Grandi, G; Vriend, G; Hardy, F; Veltman, OR; Venema, G; Eijsink, VGH

    The present study concerns the use of site-directed mutagenesis experiments to optimize a three-dimensional model of the neutral protease of Bacillus subtilis (NP-sub), An initial model of NP-sub was constructed using the crystal structures of the homologous neutral proteases of Bacillus

  13. Cold denaturation of the HIV-1 protease monomer

    DEFF Research Database (Denmark)

    Rösner, Heike Ilona; Caldarini, Martina; Prestel, Andreas

    2017-01-01

    The HIV-1-protease is a complex protein which in its active form adopts a homodimer dominated by -sheet structures. We have discovered a cold-denatured state of the monomeric subunit of HIV-1-protease which is populated above 0ºC and therefore directly accessible to various spectroscopic approac...

  14. Oxidant and solvent stable alkaline protease from Aspergillus flavus ...

    African Journals Online (AJOL)

    The increase in agricultural practices has necessitated the judicious use of agricultural wastes into value added products. In this study, an extracellular, organic solvent and oxidant stable, serine protease was produced by Aspergillus flavus MTCC 9952 under solid state fermentation. Maximum protease yield was obtained ...

  15. Some physicochemical properties of acid protease produced during ...

    African Journals Online (AJOL)

    The growth of Aspergillus niger (NRRL 1785) was investigated and monitored over a five-day fermentation period. Acid protease synthesis by this fungus was also investigated during the period. The effect of growth of Aspergillus niger on acid protease synthesis was determined. Some of the physicochemical properties of ...

  16. Improvement of acid protease production by a mixed culture of ...

    African Journals Online (AJOL)

    The synthesis of acid protease by Aspergillus oryzae AS3042 was enhanced significantly with the mixed culture of Aspergillus niger SL-09 using solid-state fermentation technique. The influence of carbon sources, nitrogen sources and the addition of phytic acid on acid protease production were investigated. The enzyme ...

  17. Partial purification and characterization of alkaline proteases from ...

    African Journals Online (AJOL)

    Alkaline proteases from the digestive tract of anchovy were partially purified by ammonium sulfate fractionation, dialysis and Sephadex G-75 gel filtration. The purification fold and yield were 6.23 and 4.49%, respectively. The optimum activities of partially purified alkaline proteases were observed at 60°C and at pH 11.0.

  18. High-level expression of alkaline protease using recombinant ...

    African Journals Online (AJOL)

    AJL

    2012-02-16

    Feb 16, 2012 ... compared with that of wild-type B. licheniformis CICIM B5102. Key word: Alkaline protease, Bacillus amyloliquefaciens, Bacillus licheniformis. INTRODUCTION. Proteases are one of the most important industrial enzyme groups, accounting for approximately 60% of the total enzyme sales (Beg et al., 2003).

  19. Isolation of protease producing novel Bacillus cereus and detection ...

    African Journals Online (AJOL)

    user

    2011-02-14

    Feb 14, 2011 ... The highest protease activity was determined at 30°C temperature and 6.4 pH conditions and after the 18th hour, it decreased evidently. Key words: Protease, production, optimization, Bacillus sp. INTRODUCTION. Enzymes have been produced in large industrial scale for several decades (Falch, 1991).

  20. Production of alkaline proteases by alkalophilic Bacillus subtilis ...

    African Journals Online (AJOL)

    Among various nitrogen sources, yeast extract was found to be the best inducer of alkaline protease. Among metal salts, KNO3 and NH4Cl were found to increase protease production. The maximum enzyme production (3600 U/ml) was observed with pomegranate peels of fermentation medium in the presence of yeast ...

  1. Myeloablation-associated deletion of ORF4 in a human coronavirus 229E infection.

    Science.gov (United States)

    Greninger, Alexander L; Pepper, Gregory; Shean, Ryan C; Cent, Anne; Palileo, Isabel; Kuypers, Jane M; Schiffer, Joshua T; Jerome, Keith R

    2017-01-01

    We describe metagenomic next-generation sequencing (mNGS) of a human coronavirus 229E from a patient with AML and persistent upper respiratory symptoms, who underwent hematopoietic cell transplantation (HCT). mNGS revealed a 548-nucleotide deletion, which comprised the near entirety of the ORF4 gene, and no minor allele variants were detected to suggest a mixed infection. As part of her pre-HCT conditioning regimen, the patient received myeloablative treatment with cyclophosphamide and 12 Gy total body irradiation. Iterative sequencing and RT-PCR confirmation of four respiratory samples over the 4-week peritransplant period revealed that the pre-conditioning strain contained an intact ORF4 gene, while the deletion strain appeared just after conditioning and persisted over a 2.5-week period. This sequence represents one of the largest genomic deletions detected in a human RNA virus and describes large-scale viral mutation associated with myeloablation for HCT.

  2. Conservation of nucleotide sequences for molecular diagnosis of Middle East respiratory syndrome coronavirus, 2015

    Directory of Open Access Journals (Sweden)

    Yuki Furuse

    2015-11-01

    Full Text Available Infection due to the Middle East respiratory syndrome coronavirus (MERS-CoV is widespread. The present study was performed to assess the protocols used for the molecular diagnosis of MERS-CoV by analyzing the nucleotide sequences of viruses detected between 2012 and 2015, including sequences from the large outbreak in eastern Asia in 2015. Although the diagnostic protocols were established only 2 years ago, mismatches between the sequences of primers/probes and viruses were found for several of the assays. Such mismatches could lead to a lower sensitivity of the assay, thereby leading to false-negative diagnosis. A slight modification in the primer design is suggested. Protocols for the molecular diagnosis of viral infections should be reviewed regularly after they are established, particularly for viruses that pose a great threat to public health such as MERS-CoV.

  3. Replication of murine coronavirus requires multiple cysteines in the endodomain of spike protein

    International Nuclear Information System (INIS)

    Yang, Jinhua; Lv, Jun; Wang, Yuyan; Gao, Shuang; Yao, Qianqian; Qu, Di; Ye, Rong

    2012-01-01

    A conserved cysteine-rich motif located between the transmembrane domain and the endodomain is essential for membrane fusion and assembly of coronavirus spike (S) protein. Here, we proved that three cysteines within the motif, but not dependent on position, are minimally required for the survival of the recombinant mouse hepatitis virus. When the carboxy termini with these mutated motifs of S proteins were respectively introduced into a heterogeneous protein, both incorporation into lipid rafts and S-palmitoylation of these recombinant proteins showed a similar quantity requirement to cysteine residues. Meanwhile, the redistribution of these proteins on cellular surface indicated that the absence of the positively charged rather than cysteine residues in the motif might lead the dramatic reduction in syncytial formation of some mutants with the deleted motifs. These results suggest that multiple cysteine as well as charged residues concurrently improves the membrane-associated functions of S protein in viral replication and cytopathogenesis.

  4. Vaccines for emerging infectious diseases: Lessons from MERS coronavirus and Zika virus

    Science.gov (United States)

    Maslow, Joel N.

    2017-01-01

    ABSTRACT The past decade and a half has been characterized by numerous emerging infectious diseases. With each new threat, there has been a call for rapid vaccine development. Pathogens such as the Middle East Respiratory Syndrome coronavirus (MERS-CoV) and the Zika virus represent either new viral entities or viruses emergent in new geographic locales and characterized by novel complications. Both serve as paradigms for the global spread that can accompany new pathogens. In this paper, we review the epidemiology and pathogenesis of MERS-CoV and Zika virus with respect to vaccine development. The challenges in vaccine development and the approach to clinical trial design to test vaccine candidates for disease entities with a changing epidemiology are discussed. PMID:28846484

  5. Detection of Avian coronavirus infectious bronchitis virus type QX infection in Switzerland.

    Science.gov (United States)

    Sigrist, Brigitte; Tobler, Kurt; Schybli, Martina; Konrad, Leonie; Stöckli, René; Cattoli, Giovanni; Lüschow, Dörte; Hafez, Hafez M; Britton, Paul; Hoop, Richard K; Vögtlin, Andrea

    2012-11-01

    Infectious bronchitis, a disease of chickens caused by Avian coronavirus infectious bronchitis virus (IBV), leads to severe economic losses for the poultry industry worldwide. Various attempts to control the virus based on vaccination strategies are performed. However, due to the emergence of novel genotypes, an effective control of the virus is hindered. In 1996, a novel viral genotype named IBV-QX was reported for the first time in Qingdao, Shandong province, China. The first appearance of an IBV-QX isolate in Europe was reported between 2003 and 2004 in The Netherlands. Subsequently, infections with this genotype were found in several other European countries such as France, Italy, Germany, United Kingdom, Slovenia, and Sweden. The present report describes the use of a new set of degenerate primers that amplify a 636-bp fragment within the S1 gene by reverse transcription polymerase chain reaction to detect the occurrence of IBV-QX infection in Switzerland.

  6. Dromedary camels and the transmission of Middle East Respiratory Syndrome Coronavirus (MERS-CoV)

    Science.gov (United States)

    Hemida, Maged G; Elmoslemany, Ahmed; Al-Hizab, Fahad; Alnaeem, Abdulmohsen; Almathen, Faisal; Faye, Bernard; Chu, Daniel KW; Perera, Ranawaka A; Peiris, Malik

    2015-01-01

    Middle East respiratory syndrome coronavirus (MERS-CoV) is an existential threat to global public health. The virus has been repeatedly detected in dromedary camels (Camelus dromedarius). Adult animals in many countries in the Middle East as well as in North and East Africa showed high (>90%) sero-prevalence to the virus. MERS-CoV isolated from dromedaries is genetically and phenotypically similar to viruses from humans. We summarise current understanding of the ecology of MERS-CoV in animals and transmission at the animal-human interface. We review aspects of husbandry, animal movements and trade and the use and consumption of camel dairy and meat products in the Middle East that may be relevant to the epidemiology of MERS. We also highlight the gaps in understanding the transmission of this virus in animals and from animals to humans. PMID:26256102

  7. Dynamics of SARS-coronavirus HR2 domain in the prefusion and transition states

    Science.gov (United States)

    McReynolds, Susanna; Jiang, Shaokai; Rong, Lijun; Caffrey, Michael

    2009-12-01

    The envelope glycoproteins S1 and S2 of severe acute respiratory syndrome coronavirus (SARS-CoV) mediate viral entry by conformational change from a prefusion state to a postfusion state that enables fusion of the viral and target membranes. In this work we present the characterization of the dynamic properties of the SARS-CoV S2-HR2 domain (residues 1141-1193 of S) in the prefusion and newly discovered transition states by NMR 15N relaxation studies. The dynamic properties of the different states, which are stabilized under different experimental conditions, extend the current model of viral membrane fusion and give insight into the design of structure-based antagonists of SARS-CoV in particular, as well as other enveloped viruses such as HIV.

  8. Human Neutralizing Monoclonal Antibody Inhibition of Middle East Respiratory Syndrome Coronavirus Replication in the Common Marmoset.

    Science.gov (United States)

    Chen, Zhe; Bao, Linlin; Chen, Cong; Zou, Tingting; Xue, Ying; Li, Fengdi; Lv, Qi; Gu, Songzhi; Gao, Xiaopan; Cui, Sheng; Wang, Jianmin; Qin, Chuan; Jin, Qi

    2017-06-15

    Middle East respiratory syndrome coronavirus (MERS-CoV) infection in humans is highly lethal, with a fatality rate of 35%. New prophylactic and therapeutic strategies to combat human infections are urgently needed. We isolated a fully human neutralizing antibody, MCA1, from a human survivor. The antibody recognizes the receptor-binding domain of MERS-CoV S glycoprotein and interferes with the interaction between viral S and the human cellular receptor human dipeptidyl peptidase 4 (DPP4). To our knowledge, this study is the first to report a human neutralizing monoclonal antibody that completely inhibits MERS-CoV replication in common marmosets. Monotherapy with MCA1 represents a potential alternative treatment for human infections with MERS-CoV worthy of evaluation in clinical settings. © Crown copyright 2017.

  9. Detection of ascitic feline coronavirus RNA from cats with clinically suspected feline infectious peritonitis.

    Science.gov (United States)

    Soma, Takehisa; Wada, Makoto; Taharaguchi, Satoshi; Tajima, Tomoko

    2013-10-01

    Ascitic feline coronavirus (FCoV) RNA was examined in 854 cats with suspected feline infectious peritonitis (FIP) by RT-PCR. The positivity was significantly higher in purebreds (62.2%) than in crossbreds (34.8%) (P<0.0001). Among purebreds, the positivities in the Norwegian forest cat (92.3%) and Scottish fold (77.6%) were significantly higher than the average of purebreds (P=0.0274 and 0.0251, respectively). The positivity was significantly higher in males (51.5%) than in females (35.7%) (P<0.0001), whereas no gender difference has generally been noted in FCoV antibody prevalence, indicating that FIP more frequently develops in males among FCoV-infected cats. Genotyping was performed for 377 gene-positive specimens. Type I (83.3%) was far more predominantly detected than type II (10.6%) (P<0.0001), similar to previous serological and genetic surveys.

  10. Replication of murine coronavirus requires multiple cysteines in the endodomain of spike protein

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jinhua; Lv, Jun; Wang, Yuyan; Gao, Shuang; Yao, Qianqian; Qu, Di; Ye, Rong, E-mail: yerong24@fudan.edu.cn

    2012-06-05

    A conserved cysteine-rich motif located between the transmembrane domain and the endodomain is essential for membrane fusion and assembly of coronavirus spike (S) protein. Here, we proved that three cysteines within the motif, but not dependent on position, are minimally required for the survival of the recombinant mouse hepatitis virus. When the carboxy termini with these mutated motifs of S proteins were respectively introduced into a heterogeneous protein, both incorporation into lipid rafts and S-palmitoylation of these recombinant proteins showed a similar quantity requirement to cysteine residues. Meanwhile, the redistribution of these proteins on cellular surface indicated that the absence of the positively charged rather than cysteine residues in the motif might lead the dramatic reduction in syncytial formation of some mutants with the deleted motifs. These results suggest that multiple cysteine as well as charged residues concurrently improves the membrane-associated functions of S protein in viral replication and cytopathogenesis.

  11. Vaccines for emerging infectious diseases: Lessons from MERS coronavirus and Zika virus.

    Science.gov (United States)

    Maslow, Joel N

    2017-12-02

    The past decade and a half has been characterized by numerous emerging infectious diseases. With each new threat, there has been a call for rapid vaccine development. Pathogens such as the Middle East Respiratory Syndrome coronavirus (MERS-CoV) and the Zika virus represent either new viral entities or viruses emergent in new geographic locales and characterized by novel complications. Both serve as paradigms for the global spread that can accompany new pathogens. In this paper, we review the epidemiology and pathogenesis of MERS-CoV and Zika virus with respect to vaccine development. The challenges in vaccine development and the approach to clinical trial design to test vaccine candidates for disease entities with a changing epidemiology are discussed.

  12. Severe acute respiratory syndrome--a new coronavirus from the Chinese dragon's lair

    DEFF Research Database (Denmark)

    Knudsen, T B; Kledal, T N; Andersen, O

    2003-01-01

    Health Organization (WHO). As SARS has the potential of becoming the first pandemic of the new millennium, a global warning by the WHO was issued on 12 March 2003. The disease, which is believed to have its origin in the Chinese Guangdong province, spread from Hong Kong via international airports to its...... disease constitutes an unprecedented scientific achievement. The main scope of the article is to provide the clinician with an overview of the natural history, epidemiology and clinical characteristics of SARS. On the basis of the recently published viral genome and structural features common...... to the members of the coronavirus family, a model for host cell-virus interaction and possible targets for antiviral drugs are presented. The epidemiological consequences of introducing a novel pathogen in a previously unexposed population and the origin and evolution of a new and more pathogenic strain...

  13. Prolonged Shedding of Human Coronavirus in Hematopoietic Cell Transplant Recipients: Risk Factors and Viral Genome Evolution.

    Science.gov (United States)

    Ogimi, Chikara; Greninger, Alexander L; Waghmare, Alpana A; Kuypers, Jane M; Shean, Ryan C; Xie, Hu; Leisenring, Wendy M; Stevens-Ayers, Terry L; Jerome, Keith R; Englund, Janet A; Boeckh, Michael

    2017-07-15

    Recent data suggest that human coronavirus (HCoV) pneumonia is associated with significant mortality in hematopoietic cell transplant (HCT) recipients. Investigation of risk factors for prolonged shedding and intrahost genome evolution may provide critical information for development of novel therapeutics. We retrospectively reviewed HCT recipients with HCoV detected in nasal samples by polymerase chain reaction (PCR). HCoV strains were identified using strain-specific PCR. Shedding duration was defined as time between first positive and first negative sample. Logistic regression analyses were performed to evaluate factors for prolonged shedding (≥21 days). Metagenomic next-generation sequencing (mNGS) was conducted when ≥4 samples with cycle threshold values of Genome changes were consistent with the expected molecular clock of HCoV. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

  14. Functional Implications of Domain Organization Within Prokaryotic Rhomboid Proteases.

    Science.gov (United States)

    Panigrahi, Rashmi; Lemieux, M Joanne

    2015-01-01

    Intramembrane proteases are membrane embedded enzymes that cleave transmembrane substrates. This interesting class of enzyme and its water mediated substrate cleavage mechanism occurring within the hydrophobic lipid bilayer has drawn the attention of researchers. Rhomboids are a family of ubiquitous serine intramembrane proteases. Bacterial forms of rhomboid proteases are mainly composed of six transmembrane helices that are preceded by a soluble N-terminal domain. Several crystal structures of the membrane domain of the E. coli rhomboid protease ecGlpG have been solved. Independently, the ecGlpG N-terminal cytoplasmic domain structure was solved using both NMR and protein crystallography. Despite these structures, we still do not know the structure of the full-length protein, nor do we know the functional role of these domains in the cell. This chapter will review the structural and functional roles of the different domains associated with prokaryotic rhomboid proteases. Lastly, we will address questions remaining in the field.

  15. The Degradome database: mammalian proteases and diseases of proteolysis.

    Science.gov (United States)

    Quesada, Víctor; Ordóñez, Gonzalo R; Sánchez, Luis M; Puente, Xose S; López-Otín, Carlos

    2009-01-01

    The degradome is defined as the complete set of proteases present in an organism. The recent availability of whole genomic sequences from multiple organisms has led us to predict the contents of the degradomes of several mammalian species. To ensure the fidelity of these predictions, our methods have included manual curation of individual sequences and, when necessary, direct cloning and sequencing experiments. The results of these studies in human, chimpanzee, mouse and rat have been incorporated into the Degradome database, which can be accessed through a web interface at http://degradome.uniovi.es. The annotations about each individual protease can be retrieved by browsing catalytic classes and families or by searching specific terms. This web site also provides detailed information about genetic diseases of proteolysis, a growing field of great importance for multiple users. Finally, the user can find additional information about protease structures, protease inhibitors, ancillary domains of proteases and differences between mammalian degradomes.

  16. In Situ Tagged nsp15 Reveals Interactions with Coronavirus Replication/Transcription Complex-Associated Proteins

    Directory of Open Access Journals (Sweden)

    Jeremiah Athmer

    2017-01-01

    Full Text Available Coronavirus (CoV replication and transcription are carried out in close proximity to restructured endoplasmic reticulum (ER membranes in replication/transcription complexes (RTC. Many of the CoV nonstructural proteins (nsps are required for RTC function; however, not all of their functions are known. nsp15 contains an endoribonuclease domain that is conserved in the CoV family. While the enzymatic activity and crystal structure of nsp15 are well defined, its role in replication remains elusive. nsp15 localizes to sites of RNA replication, but whether it acts independently or requires additional interactions for its function remains unknown. To begin to address these questions, we created an in situ tagged form of nsp15 using the prototypic CoV, mouse hepatitis virus (MHV. In MHV, nsp15 contains the genomic RNA packaging signal (P/S, a 95-bp RNA stem-loop structure that is not required for viral replication or nsp15 function. Utilizing this knowledge, we constructed an internal hemagglutinin (HA tag that replaced the P/S. We found that nsp15-HA was localized to discrete perinuclear puncta and strongly colocalized with nsp8 and nsp12, both well-defined members of the RTC, but not the membrane (M protein, involved in virus assembly. Finally, we found that nsp15 interacted with RTC-associated proteins nsp8 and nsp12 during infection, and this interaction was RNA independent. From this, we conclude that nsp15 localizes and interacts with CoV proteins in the RTC, suggesting it plays a direct or indirect role in virus replication. Furthermore, the use of in situ epitope tags could be used to determine novel nsp-nsp interactions in coronaviruses.

  17. Plaque assay for human coronavirus NL63 using human colon carcinoma cells

    Directory of Open Access Journals (Sweden)

    Drosten Christian

    2008-11-01

    Full Text Available Abstract Background Coronaviruses cause a broad range of diseases in animals and humans. Human coronavirus (hCoV NL63 is associated with up to 10% of common colds. Viral plaque assays enable the characterization of virus infectivity and allow for purifying virus stock solutions. They are essential for drug screening. Hitherto used cell cultures for hCoV-NL63 show low levels of virus replication and weak and diffuse cytopathogenic effects. It has not yet been possible to establish practicable plaque assays for this important human pathogen. Results 12 different cell cultures were tested for susceptibility to hCoV-NL63 infection. Human colon carcinoma cells (CaCo-2 replicated virus more than 100 fold more efficiently than commonly used African green monkey kidney cells (LLC-MK2. CaCo-2 cells showed cytopathogenic effects 4 days post infection. Avicel, agarose and carboxymethyl-cellulose overlays proved suitable for plaque assays. Best results were achieved with Avicel, which produced large and clear plaques from the 4th day of infection. The utility of plaque assays with agrose overlay was demonstrated for purifying virus, thereby increasing viral infectivity by 1 log 10 PFU/mL. Conclusion CaCo-2 cells support hCoV-NL63 better than LLC-MK2 cells and enable cytopathogenic plaque assays. Avicel overlay is favourable for plaque quantification, and agarose overlay is preferred for plaque purification. HCoV-NL63 virus stock of increased infectivity will be beneficial in antiviral screening, animal modelling of disease, and other experimental tasks.

  18. A human coronavirus responsible for the common cold massively kills dendritic cells but not monocytes.

    Science.gov (United States)

    Mesel-Lemoine, Mariana; Millet, Jean; Vidalain, Pierre-Olivier; Law, Helen; Vabret, Astrid; Lorin, Valérie; Escriou, Nicolas; Albert, Matthew L; Nal, Béatrice; Tangy, Frédéric

    2012-07-01

    Human coronaviruses are associated with upper respiratory tract infections that occasionally spread to the lungs and other organs. Although airway epithelial cells represent an important target for infection, the respiratory epithelium is also composed of an elaborate network of dendritic cells (DCs) that are essential sentinels of the immune system, sensing pathogens and presenting foreign antigens to T lymphocytes. In this report, we show that in vitro infection by human coronavirus 229E (HCoV-229E) induces massive cytopathic effects in DCs, including the formation of large syncytia and cell death within only few hours. In contrast, monocytes are much more resistant to infection and cytopathic effects despite similar expression levels of CD13, the membrane receptor for HCoV-229E. While the differentiation of monocytes into DCs in the presence of granulocyte-macrophage colony-stimulating factor and interleukin-4 requires 5 days, only 24 h are sufficient for these cytokines to sensitize monocytes to cell death and cytopathic effects when infected by HCoV-229E. Cell death induced by HCoV-229E is independent of TRAIL, FasL, tumor necrosis factor alpha, and caspase activity, indicating that viral replication is directly responsible for the observed cytopathic effects. The consequence of DC death at the early stage of HCoV-229E infection may have an impact on the early control of viral dissemination and on the establishment of long-lasting immune memory, since people can be reinfected multiple times by HCoV-229E.

  19. Middle East respiratory syndrome coronavirus disease is rare in children: An update from Saudi Arabia.

    Science.gov (United States)

    Al-Tawfiq, Jaffar A; Kattan, Rana F; Memish, Ziad A

    2016-11-08

    To summarize the reported Middle East respiratory syndrome-coronavirus (MERS-CoV) cases, the associated clinical presentations and the outcomes. We searched the Saudi Ministry of Health website, the World Health Organization website, and the Flutracker website. We also searched MEDLINE and PubMed for the keywords: Middle East respiratory syndrome-coronavirus, MERS-CoV in combination with pediatric, children, childhood, infancy and pregnancy from the initial discovery of the virus in 2012 to 2016. The retrieved articles were also read to further find other articles. Relevant data were placed into an excel sheet and analyzed accordingly. Descriptive analytic statistics were used in the final analysis as deemed necessary. From June 2012 to April 19, 2016, there were a total of 31 pediatric MERS-CoV cases. Of these cases 13 (42%) were asymptomatic and the male to female ratio was 1.7:1. The mean age of patients was 9.8 ± 5.4 years. Twenty-five (80.6%) of the cases were reported from the Kingdom of Saudi Arabia. The most common source of infection was household contact (10 of 15 with reported source) and 5 patients acquired infection within a health care facility. Using real time reverse transcriptase polymerase chain reaction of pediatric patients revealed that 9 out of 552 (1.6%) was positive in the Kingdom of Saudi Arabia. Utilizing serology for MERS-CoV infection in Jordan and Saudi Arabia did not reveal any positive patients. Thus, the number of the pediatric MERS-CoV is low; the exact reason for the low prevalence of the disease in children is not known.

  20. Isolation and molecular characterization of type I and type II feline coronavirus in Malaysia

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    Amer Alazawy

    2012-11-01

    Full Text Available Abstract Background Feline infectious peritonitis virus (FIPV and feline enteric coronavirus (FECV are two important coronaviruses of domestic cat worldwide. Although FCoV is prevalent among cats; the fastidious nature of type I FCoV to grow on cell culture has limited further studies on tissue tropism and pathogenesis of FCoV. While several studies reported serological evidence for FCoV in Malaysia, neither the circulating FCoV isolated nor its biotypes determined. This study for the first time, describes the isolation and biotypes determination of type I and type II FCoV from naturally infected cats in Malaysia. Findings Of the total number of cats sampled, 95% (40/42 were RT-PCR positive for FCoV. Inoculation of clinical samples into Crandell feline kidney cells (CrFK, and Feline catus whole fetus-4 cells (Fcwf-4, show cytopathic effect (CPE characterized by syncytial cells formation and later cell detachment. Differentiation of FCoV biotypes using RT-PCR assay revealed that, 97.5% and 2.5% of local isolates were type I and type II FCoV, respectively. These isolates had high sequence homology and phylogenetic similarity with several FCoV isolates from Europe, South East Asia and USA. Conclusions This study reported the successful isolation of local type I and type II FCoV evident with formation of cytopathic effects in two types of cell cultures namely the CrFK and Fcwf-4 , where the later cells being more permissive. However, the RT-PCR assay is more sensitive in detecting the antigen in suspected samples as compared to virus isolation in cell culture. The present study indicated that type I FCoV is more prevalent among cats in Malaysia.

  1. Isolation and molecular characterization of type I and type II feline coronavirus in Malaysia.

    Science.gov (United States)

    Amer, Alazawy; Siti Suri, Arshad; Abdul Rahman, Omar; Mohd, Hair Bejo; Faruku, Bande; Saeed, Sharif; Tengku Azmi, Tengku Ibrahim

    2012-11-21

    Feline infectious peritonitis virus (FIPV) and feline enteric coronavirus (FECV) are two important coronaviruses of domestic cat worldwide. Although FCoV is prevalent among cats; the fastidious nature of type I FCoV to grow on cell culture has limited further studies on tissue tropism and pathogenesis of FCoV. While several studies reported serological evidence for FCoV in Malaysia, neither the circulating FCoV isolated nor its biotypes determined. This study for the first time, describes the isolation and biotypes determination of type I and type II FCoV from naturally infected cats in Malaysia. Of the total number of cats sampled, 95% (40/42) were RT-PCR positive for FCoV. Inoculation of clinical samples into Crandell feline kidney cells (CrFK), and Feline catus whole fetus-4 cells (Fcwf-4), show cytopathic effect (CPE) characterized by syncytial cells formation and later cell detachment. Differentiation of FCoV biotypes using RT-PCR assay revealed that, 97.5% and 2.5% of local isolates were type I and type II FCoV, respectively. These isolates had high sequence homology and phylogenetic similarity with several FCoV isolates from Europe, South East Asia and USA. This study reported the successful isolation of local type I and type II FCoV evident with formation of cytopathic effects in two types of cell cultures namely the CrFK and Fcwf-4 , where the later cells being more permissive. However, the RT-PCR assay is more sensitive in detecting the antigen in suspected samples as compared to virus isolation in cell culture. The present study indicated that type I FCoV is more prevalent among cats in Malaysia.

  2. Cross genome comparisons of serine proteases in Arabidopsis and rice

    Directory of Open Access Journals (Sweden)

    Sowdhamini R

    2006-08-01

    Full Text Available Abstract Background Serine proteases are one of the largest groups of proteolytic enzymes found across all kingdoms of life and are associated with several essential physiological pathways. The availability of Arabidopsis thaliana and rice (Oryza sativa genome sequences has permitted the identification and comparison of the repertoire of serine protease-like proteins in the two plant species. Results Despite the differences in genome sizes between Arabidopsis and rice, we identified a very similar number of serine protease-like proteins in the two plant species (206 and 222, respectively. Nearly 40% of the above sequences were identified as potential orthologues. Atypical members could be identified in the plant genomes for Deg, Clp, Lon, rhomboid proteases and species-specific members were observed for the highly populated subtilisin and serine carboxypeptidase families suggesting multiple lateral gene transfers. DegP proteases, prolyl oligopeptidases, Clp proteases and rhomboids share a significantly higher percentage orthology between the two genomes indicating substantial evolutionary divergence was set prior to speciation. Single domain architectures and paralogues for several putative subtilisins, serine carboxypeptidases and rhomboids suggest they may have been recruited for additional roles in secondary metabolism with spatial and temporal regulation. The analysis reveals some domain architectures unique to either or both of the plant species and some inactive proteases, like in rhomboids and Clp proteases, which could be involved in chaperone function. Conclusion The systematic analysis of the serine protease-like proteins in the two plant species has provided some insight into the possible functional associations of previously uncharacterised serine protease-like proteins. Further investigation of these aspects may prove beneficial in our understanding of similar processes in commercially significant crop plant species.

  3. Characterization of the expression and immunogenicity of the ns4b protein of human coronavirus 229E

    DEFF Research Database (Denmark)

    Chagnon, F; Lamarre, A; Lachance, C

    1998-01-01

    to demonstrate the expression of ns4b in HCV-229E-infected cells using flow cytometry. Given a previously reported contiguous five amino acid shared region between ns4b and myelin basic protein, a purified recombinant histidine-tagged ns4b protein and (or) human myelin basic protein were injected into mice......Sequencing of complementary DNAs prepared from various coronaviruses has revealed open reading frames encoding putative proteins that are yet to be characterized and are so far only described as nonstructural (ns). As a first step in the elucidation of its function, we characterized the expression...... and immunogenicity of the ns4b gene product from strain 229E of human coronavirus (HCV-229E), a respiratory virus with a neurotropic potential. The gene was cloned and expressed in bacteria. A fusion protein of ns4b with maltose-binding protein was injected into rabbits to generate specific antibodies that were used...

  4. Sialic Acid Binding Properties of Soluble Coronavirus Spike (S1 Proteins: Differences between Infectious Bronchitis Virus and Transmissible Gastroenteritis Virus

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    Christine Winter

    2013-07-01

    Full Text Available The spike proteins of a number of coronaviruses are able to bind to sialic acids present on the cell surface. The importance of this sialic acid binding ability during infection is, however, quite different. We compared the spike protein of transmissible gastroenteritis virus (TGEV and the spike protein of infectious bronchitis virus (IBV. Whereas sialic acid is the only receptor determinant known so far for IBV, TGEV requires interaction with its receptor aminopeptidase N to initiate infection of cells. Binding tests with soluble spike proteins carrying an IgG Fc-tag revealed pronounced differences between these two viral proteins. Binding of the IBV spike protein to host cells was in all experiments sialic acid dependent, whereas the soluble TGEV spike showed binding to APN but had no detectable sialic acid binding activity. Our results underline the different ways in which binding to sialoglycoconjugates is mediated by coronavirus spike proteins.

  5. Highly potent fibrinolytic serine protease from Streptomyces.

    Science.gov (United States)

    Uesugi, Yoshiko; Usuki, Hirokazu; Iwabuchi, Masaki; Hatanaka, Tadashi

    2011-01-05

    We introduce a highly potent fibrinolytic serine protease from Streptomyces omiyaensis (SOT), which belongs to the trypsin family. The fibrinolytic activity of SOT was examined using in vitro assays and was compared with those of known fibrinolytic enzymes such as plasmin, tissue-type plasminogen activator (t-PA), urokinase, and nattokinase. Compared to other enzymes, SOT showed remarkably higher hydrolytic activity toward mimic peptides of fibrin and plasminogen. The fibrinolytic activity of SOT is about 18-fold higher than that of plasmin, and is comparable to that of t-PA by fibrin plate assays. Furthermore, SOT had some plasminogen activator-like activity. Results show that SOT and nattokinase have very different fibrinolytic and fibrinogenolytic modes, engendering significant synergetic effects of SOT and nattokinase on fibrinolysis. These results suggest that SOT presents important possibilities for application in the therapy of thrombosis. Copyright © 2010 Elsevier Inc. All rights reserved.

  6. Characterization of a secreted Chlamydia protease

    DEFF Research Database (Denmark)

    Shaw, A.C.; Vandahl, B.B.; Larsen, M.R.

    2002-01-01

    Chlamydiae are obligate intracellular bacteria that are important human pathogens. The Chlamydia genomes contain orthologues to secretion apparatus proteins from other intracellular bacteria, but only a few secreted proteins have been identified. Most likely, effector proteins are secreted in order...... to promote infection. Effector proteins cannot be identified by motif or similarity searches. As a new strategy for identification of secreted proteins we have compared 2D-PAGE profiles of [35S]-labelled Chlamydia proteins from whole lysates of infected cells to 2D-PAGE profiles of proteins from purified...... Chlamydia. Several secretion candidates from Chlamydia trachomatis D and Chlamydia pneumoniae were detected by this method. Two protein spots were identified among the candidates. These represent fragments of the 'chlamydial protease- or proteasome-like activity factor' (CPAF) and were clearly present in 2D...

  7. Achieving a golden mean: mechanisms by which coronaviruses ensure synthesis of the correct stoichiometric ratios of viral proteins.

    Science.gov (United States)

    Plant, Ewan P; Rakauskaite, Rasa; Taylor, Deborah R; Dinman, Jonathan D

    2010-05-01

    In retroviruses and the double-stranded RNA totiviruses, the efficiency of programmed -1 ribosomal frameshifting is critical for ensuring the proper ratios of upstream-encoded capsid proteins to downstream-encoded replicase enzymes. The genomic organizations of many other frameshifting viruses, including the coronaviruses, are very different, in that their upstream open reading frames encode nonstructural proteins, the frameshift-dependent downstream open reading frames encode enzymes involved in transcription and replication, and their structural proteins are encoded by subgenomic mRNAs. The biological significance of frameshifting efficiency and how the relative ratios of proteins encoded by the upstream and downstream open reading frames affect virus propagation has not been explored before. Here, three different strategies were employed to test the hypothesis that the -1 PRF signals of coronaviruses have evolved to produce the correct ratios of upstream- to downstream-encoded proteins. Specifically, infectious clones of the severe acute respiratory syndrome (SARS)-associated coronavirus harboring mutations that lower frameshift efficiency decreased infectivity by >4 orders of magnitude. Second, a series of frameshift-promoting mRNA pseudoknot mutants was employed to demonstrate that the frameshift signals of the SARS-associated coronavirus and mouse hepatitis virus have evolved to promote optimal frameshift efficiencies. Finally, we show that a previously described frameshift attenuator element does not actually affect frameshifting per se but rather serves to limit the fraction of ribosomes available for frameshifting. The findings of these analyses all support a "golden mean" model in which viruses use both programmed ribosomal frameshifting and translational attenuation to control the relative ratios of their encoded proteins.

  8. A case of imported Middle East Respiratory Syndrome coronavirus infection and public health response, Greece, April 2014.

    Science.gov (United States)

    Tsiodras, S; Baka, A; Mentis, A; Iliopoulos, D; Dedoukou, X; Papamavrou, G; Karadima, S; Emmanouil, M; Kossyvakis, A; Spanakis, N; Pavli, A; Maltezou, H; Karageorgou, A; Spala, G; Pitiriga, V; Kosmas, E; Tsiagklis, S; Gkatzias, S; Koulouris, Ng; Koutsoukou, A; Bakakos, P; Markozanhs, E; Dionellis, G; Pontikis, K; Rovina, N; Kyriakopoulou, M; Efstathiou, P; Papadimitriou, T; Kremastinou, J; Tsakris, A; Saroglou, G

    2014-04-24

    On 18 April 2014, a case of Middle East Respiratory Syndrome coronavirus (MERS-CoV) infection was laboratory confirmed in Athens, Greece in a patient returning from Jeddah, Saudi Arabia. Main symptoms upon initial presentation were protracted fever and diarrhoea, during hospitalisation he developed bilateral pneumonia and his condition worsened. During 14 days prior to onset of illness, he had extensive contact with the healthcare environment in Jeddah. Contact tracing revealed 73 contacts, no secondary cases had occurred by 22 April.

  9. Human coronavirus 229E encodes a single ORF4 protein between the spike and the envelope genes

    Directory of Open Access Journals (Sweden)

    Berkhout Ben

    2006-12-01

    Full Text Available Abstract Background The genome of coronaviruses contains structural and non-structural genes, including several so-called accessory genes. All group 1b coronaviruses encode a single accessory protein between the spike and envelope genes, except for human coronavirus (HCoV 229E. The prototype virus has a split gene, encoding the putative ORF4a and ORF4b proteins. To determine whether primary HCoV-229E isolates exhibit this unusual genome organization, we analyzed the ORF4a/b region of five current clinical isolates from The Netherlands and three early isolates collected at the Common Cold Unit (CCU in Salisbury, UK. Results All Dutch isolates were identical in the ORF4a/b region at amino acid level. All CCU isolates are only 98% identical to the Dutch isolates at the nucleotide level, but more closely related to the prototype HCoV-229E (>98%. Remarkably, our analyses revealed that the laboratory adapted, prototype HCoV-229E has a 2-nucleotide deletion in the ORF4a/b region, whereas all clinical isolates carry a single ORF, 660 nt in size, encoding a single protein of 219 amino acids, which is a homologue of the ORF3 proteins encoded by HCoV-NL63 and PEDV. Conclusion Thus, the genome organization of the group 1b coronaviruses HCoV-NL63, PEDV and HCoV-229E is identical. It is possible that extensive culturing of the HCoV-229E laboratory strain resulted in truncation of ORF4. This may indicate that the protein is not essential in cell culture, but the highly conserved amino acid sequence of the ORF4 protein among clinical isolates suggests that the protein plays an important role in vivo.

  10. The Severe Acute Respiratory Syndrome (SARS-coronavirus 3a protein may function as a modulator of the trafficking properties of the spike protein

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    Tan Yee-Joo

    2005-02-01

    Full Text Available Abstract Background A recent publication reported that a tyrosine-dependent sorting signal, present in cytoplasmic tail of the spike protein of most coronaviruses, mediates the intracellular retention of the spike protein. This motif is missing from the spike protein of the severe acute respiratory syndrome-coronavirus (SARS-CoV, resulting in high level of surface expression of the spike protein when it is expressed on its own in vitro. Presentation of the hypothesis It has been shown that the severe acute respiratory syndrome-coronavirus genome contains open reading frames that encode for proteins with no homologue in other coronaviruses. One of them is the 3a protein, which is expressed during infection in vitro and in vivo. The 3a protein, which contains a tyrosine-dependent sorting signal in its cytoplasmic domain, is expressed on the cell surface and can undergo internalization. In addition, 3a can bind to the spike protein and through this interaction, it may be able to cause the spike protein to become internalized, resulting in a decrease in its surface expression. Testing the hypothesis The effects of 3a on the internalization of cell surface spike protein can be examined biochemically and the significance of the interplay between these two viral proteins during viral infection can be studied using reverse genetics methodology. Implication of the hypothesis If this hypothesis is proven, it will indicate that the severe acute respiratory syndrome-coronavirus modulates the surface expression of the spike protein via a different mechanism from other coronaviruses. The interaction between 3a and S, which are expressed from separate subgenomic RNA, would be important for controlling the trafficking properties of S. The cell surface expression of S in infected cells significantly impacts viral assembly, viral spread and viral pathogenesis. Modulation by this unique pathway could confer certain advantages during the replication of the severe

  11. Structure of HIV-1 protease determined by neutron crystallography

    International Nuclear Information System (INIS)

    Adachi, Motoyasu; Kuroki, Ryota

    2009-01-01

    HIV-1 protease is an aspartic protease, and plays an essential role in replication of HIV. To develop HIV-1 protease inhibitors through structure-based drug design, it is necessary to understand the catalytic mechanism and inhibitor recognition of HIV-1 protease. We have determined the crystal structure of HIV-1 protease in complex with KNI-272 to 1.9 A resolution by neutron crystallography in combination with 1.4 A resolution X-ray diffraction data. The results show that the carbonyl group of hydroxymethylcarbonyl (HMC) in KNI-272 forms a hydrogen bonding interaction with protonated Asp 25 and the hydrogen atom from the hydroxyl group of HMC forms a hydrogen bonding interaction with the deprotonated Asp125. This is the first neutron report for HIV-1/inhibitor complex and shows directly the locations of key hydrogen atoms in catalysis and in the binding of a transition-state analog. The results confirm key aspect of the presumed catalytic mechanism of HIV-1 protease and will aid in the further development of protease inhibitors. (author)

  12. Cysteine Protease Inhibitors as Chemotherapy: Lessons from a Parasite Target

    Science.gov (United States)

    Selzer, Paul M.; Pingel, Sabine; Hsieh, Ivy; Ugele, Bernhard; Chan, Victor J.; Engel, Juan C.; Bogyo, Matthew; Russell, David G.; Sakanari, Judy A.; McKerrow, James H.

    1999-09-01

    Papain family cysteine proteases are key factors in the pathogenesis of cancer invasion, arthritis, osteoporosis, and microbial infections. Targeting this enzyme family is therefore one strategy in the development of new chemotherapy for a number of diseases. Little is known, however, about the efficacy, selectivity, and safety of cysteine protease inhibitors in cell culture or in vivo. We now report that specific cysteine protease inhibitors kill Leishmania parasites in vitro, at concentrations that do not overtly affect mammalian host cells. Inhibition of Leishmania cysteine protease activity was accompanied by defects in the parasite's lysosome/endosome compartment resembling those seen in lysosomal storage diseases. Colocalization of anti-protease antibodies with biotinylated surface proteins and accumulation of undigested debris and protease in the flagellar pocket of treated parasites were consistent with a pathway of protease trafficking from flagellar pocket to the lysosome/endosome compartment. The inhibitors were sufficiently absorbed and stable in vivo to ameliorate the pathology associated with a mouse model of Leishmania infection.

  13. Bacillus amyloliquefaciens SUBSP. plantarum PROBIOTIC STRAINS AS PROTEASE PRODUCERS

    Directory of Open Access Journals (Sweden)

    E. V. Маtseliukh

    2015-04-01

    Full Text Available Proteases from probiotic strains of the genus Bacillus, just like the antibiotics, bacteriocins and other hydrolytic enzymes, are one of the main factors that determine their biological activity. The aim of this work was to study the synthesis and biochemical properties of proteases from two strains Bacillus amyloliquefaciens subsp. plantarum UCM B-5139 and UCM B-5140 that included in the probiotic Endosporin. The cultivation of strains was carried out in flasks under rotating for two days. The influence of physico-chemical parameters of the reaction medium on proteolytic activity was studied on partially purified protease preparations. Lytic activity was determined by turbidimetric method. On the second day of cultivation B. amyloliquefaciens subsp. plantarum UCM В-5139 and UCM В-5140 synthesized the metal-dependent peptidase and serine protease, respectively. The optimum conditions of their action were the following: temperature 37–40 °C and pH 6.5–7.0. Isolated proteases are able to lyse the living cells of Staphylococcus aureus and Candida albicans. Thus we demonstrated that B. amyloliquefaciens subsp. plantarum UCM B-5140 and UCM B-5139, included in the probiotic veterinary preparation Endosporin, produced proteolytic enzymes that hydrolyze the native insoluble proteins (elastin, fibrin and collagen. These enzymes belong to the group of neutral metal-dependent and serine proteases. They are active under physiological conditions against gram-positive bacteria and yeasts. The application of these proteases in biotechnology is considered.

  14. Characterization of HCoV-229E fusion core: Implications for structure basis of coronavirus membrane fusion

    International Nuclear Information System (INIS)

    Liu Cheng; Feng Youjun; Gao Feng; Zhang Qiangmin; Wang Ming

    2006-01-01

    Human coronavirus 229E (HCoV-229E), a member of group I coronaviruses, has been identified as one of the major viral agents causing respiratory tract diseases in humans for nearly 40 years. However, the detailed molecular mechanism of the membrane fusion mediated by the spike (S) protein of HCoV-229E remains elusive. Here, we report, for the first time, a rationally designed fusion core of HCoV-229E (HR1-SGGRGG-HR2), which was in vitro produced in GST prokaryotic expression system. Multiple lines of experimental data including gel-filtration, chemical cross-linking, and circular diagram (CD) demonstrated that the HCoV-229E fusion core possesses the typical properties of the trimer of coiled-coil heterodimer (six α-helix bundle). 3D structure modeling presents its most-likely structure, similar to those of coronaviruses that have been well-documented. Collectively, HCoV-229E S protein belongs to the type I fusion protein, which is characterized by the existence of two heptad-repeat regions (HR1 and HR2), furthermore, the available knowledge concerning HCoV-229E fusion core may make it possible to design small molecule or polypeptide drugs targeting the membrane fusion, a crucial step of HCoV-229E infection

  15. A Rare Case of Human Coronavirus 229E Associated with Acute Respiratory Distress Syndrome in a Healthy Adult

    Directory of Open Access Journals (Sweden)

    Foula Vassilara

    2018-01-01

    Full Text Available Human coronavirus 229E (HCoV-229E is one of the first coronavirus strains being described. It is linked to common cold symptoms in healthy adults. Younger children and the elderly are considered vulnerable to developing lower respiratory tract infections (LRTIs. In particular, immunocompromised patients have been reported with severe and life-threatening LRTIs attributed to HCoV-229E. We report for the first time a case of LRTI and acute respiratory distress syndrome developed in a healthy adult with no comorbidities and HCoV-229E strain identified as the only causative agent. A 45-year-old female with a clear medical history presented with fever, cough, and headache. Respiratory tract infection was diagnosed, and empirical antibiotics were started. Within two days, she developed bilateral pleural effusions, diffuse consolidations, and ground glass opacities involving all lung fields. She needed immediate oxygen supply, while ABGs deteriorated and chest imaging and PaO2/FiO2 indicated ARDS. Early administration of systemic corticosteroids led to gradual clinical improvement. Multiplex PCR from nasal secretions was positive only for HCoV-229E and negative for multiple other pathogens. It remains to be elucidated how an immunocompetent adult developed a life-threatening LRTI caused by a “benign considered” coronavirus strain, the HCoV-229E.

  16. Treatment outcomes for patients with Middle Eastern Respiratory Syndrome Coronavirus (MERS CoV) infection at a coronavirus referral center in the Kingdom of Saudi Arabia.

    Science.gov (United States)

    Al Ghamdi, Mohammed; Alghamdi, Khalid M; Ghandoora, Yasmeen; Alzahrani, Ameera; Salah, Fatmah; Alsulami, Abdulmoatani; Bawayan, Mayada F; Vaidya, Dhananjay; Perl, Trish M; Sood, Geeta

    2016-04-21

    Middle Eastern Respiratory Syndrome coronavirus (MERS-CoV) is a poorly understood disease with no known treatments. We describe the clinical features and treatment outcomes of patients with laboratory confirmed MERS-CoV at a regional referral center in the Kingdom of Saudi Arabia. In 2014, a retrospective chart review was performed on patients with a laboratory confirmed diagnosis of MERS-CoV to determine clinical and treatment characteristics associated with death. Confounding was evaluated and a multivariate logistic regression was performed to assess the independent effect of treatments administered. Fifty-one patients had an overall mortality of 37 %. Most patients were male (78 %) with a mean age of 54 years. Almost a quarter of the patients were healthcare workers (23.5 %) and 41 % had a known exposure to another person with MERS-CoV. Survival was associated with male gender, working as a healthcare worker, history of hypertension, vomiting on admission, elevated respiratory rate, abnormal lung exam, elevated alanine transaminase (ALT), clearance of MERS-CoV on repeat PCR polymerase chain reaction (PCR) testing, and mycophenolate mofetil treatment. Survival was reduced in the presence of coronary artery disease, hypotension, hypoxemia, CXR (chest X-ray) abnormalities, leukocytosis, creatinine >1 · 5 mg/dL, thrombocytopenia, anemia, and renal failure. In a multivariate analysis of treatments administered, severity of illness was the greatest predictor of reduced survival. Care for patients with MERS-CoV remains a challenge. In this retrospective cohort, interferon beta and mycophenolate mofetil treatment were predictors of increased survival in the univariate analysis. Severity of illness was the greatest predictor of reduced survival in the multivariate analysis. Larger randomized trials are needed to better evaluate the efficacy of these treatment regimens for MERS-CoV.

  17. Two-Dimensional Zymography of Proteases from Steatotic Duck Liver.

    Science.gov (United States)

    Wilkesman, Jeff; Padrón, María Fernanda; Kurz, Liliana; Rémignon, Hervé

    2017-01-01

    Protease activity present in liver cells with steatosis can be electrophoretically characterized. Zymographic techniques allow semi-quantitative results, successfully detecting cathepsin and metalloprotease activity using polyacrylamide gels copolymerized with gelatin and quantified by densitometry. By using specific inhibitors, the identity of the proteases can be confirmed. 2D zymography allows the determination of both M r. and pI of the metalloprotease and cathepsin activity present in the homogenates. The analysis of liver proteases activities in force fed ducks may elucidate the mechanisms behind steatosis development.

  18. Hyper production of alkaline protease by mutagenized bacillus subtilis

    International Nuclear Information System (INIS)

    Qureshi, A.M.; Tanseem, F.

    2010-01-01

    The purpose of this work was to augment the alkaline protease production from Bacillus subtilis by using chemical mutagen (MMS) and UV mutagenesis. A number of mutants were isolated which produce high levels of extra cellular proteases. Analysis of culture supernatants of these mutants had shown that the total amounts of proteolysis activity were increased from 1 to 2 fold over the wild strain. Clones showing promote response were further characterized by analyzing different parameters; like of Temperature, pH substrate concentration and incubation period, to study the activity of protease enzyme. (author)

  19. Optimizing PHB and Protease Production by Box Behnken Design

    Directory of Open Access Journals (Sweden)

    Amro Abd al fattah Amara

    2013-04-01

    Full Text Available Mixed culture is more suitable to adapt more flexible fermentation process and produce different product simultaneously. In this study a mixed Bacillus culture was investigated for their ability to produce the bioplastic "Polyhydroxybutyrate" and both of the mesophilic and the thermophilic proteases in one flask. Box-Behnken experimental design was used. The produced amount of PHB has been increased significantly. Meanwhile there is a competition between PHB and proteases. The maximum produced amount of PHB using Box-Behnken design was 2.82 g/l/48 h with protease activity equal to 41.9 Units/ml/48 h for thermophilic proteases and 99.65 Units/ml/48 h for mesophilic proteases. Excel solver was used for extra-optimization for the optimum conditions obtained from Box-Behnken experiments and its model. The maximum PHB obtained after using Excel solver was 2.88 g/l/48 h. The maximum mesophilic and thermophilic activities obtained at the same PHB production conditions were 175.68 and 243.38 Units/ml respectively. The model accuracy as obtained from Excel solver was 118.8%, which prove the power of the experimental design in optimizing such complicated process. The strategies used in this study are recommended for the production of PHB and different proteases simultaneously using Bacillus mixed culture. ABSTRAK: Kultur campuran adalah lebih sesuai bagi proses penapaian yang fleksibel dan ia boleh menghasilkan produk yang berbeza secara serentak. Dalam kajian ini keupayaan  menghasilkan "Polyhydroxybutyrate" bioplastik serta mesofilik dan termofilik protease dalam satu flask oleh  kultur Bacillus campuran telah disiasat. Eksperimen rekabentuk Box-Behnken telah digunakan. Jumlah PHB yang dikeluarkan meningkat dengan ketara dan terdapat persaingan antara PHB dan protease. Jumlah keluaran PHB maksima menggunakan rekabentuk Box-Behnken adalah 2.82 g/l/48 jam dengan aktiviti protease sama dengan 41.9 Unit/ml/48 jam untuk protease termofilik dan 99.65 Unit

  20. Protease-associated cellular networks in malaria parasite Plasmodium falciparum

    Directory of Open Access Journals (Sweden)

    Lilburn Timothy G

    2011-12-01

    Full Text Available Abstract Background Malaria continues to be one of the most severe global infectious diseases, responsible for 1-2 million deaths yearly. The rapid evolution and spread of drug resistance in parasites has led to an urgent need for the development of novel antimalarial targets. Proteases are a group of enzymes that play essential roles in parasite growth and invasion. The possibility of designing specific inhibitors for proteases makes them promising drug targets. Previously, combining a comparative genomics approach and a machine learning approach, we identified the complement of proteases (degradome in the malaria parasite Plasmodium falciparum and its sibling species 123, providing a catalog of targets for functional characterization and rational inhibitor design. Network analysis represents another route to revealing the role of proteins in the biology of parasites and we use this approach here to expand our understanding of the systems involving the proteases of P. falciparum. Results We investigated the roles of proteases in the parasite life cycle by constructing a network using protein-protein association data from the STRING database 4, and analyzing these data, in conjunction with the data from protein-protein interaction assays using the yeast 2-hybrid (Y2H system 5, blood stage microarray experiments 678, proteomics 9101112, literature text mining, and sequence homology analysis. Seventy-seven (77 out of 124 predicted proteases were associated with at least one other protein, constituting 2,431 protein-protein interactions (PPIs. These proteases appear to play diverse roles in metabolism, cell cycle regulation, invasion and infection. Their degrees of connectivity (i.e., connections to other proteins, range from one to 143. The largest protease-associated sub-network is the ubiquitin-proteasome system which is crucial for protein recycling and stress response. Proteases are also implicated in heat shock response, signal peptide

  1. Genome-wide identification and structure-function studies of proteases and protease inhibitors in Cicer arietinum (chickpea).

    Science.gov (United States)

    Sharma, Ranu; Suresh, C G

    2015-01-01

    Proteases are a family of enzymes present in almost all living organisms. In plants they are involved in many biological processes requiring stress response in situations such as water deficiency, pathogen attack, maintaining protein content of the cell, programmed cell death, senescence, reproduction and many more. Similarly, protease inhibitors (PIs) are involved in various important functions like suppression of invasion by pathogenic nematodes, inhibition of spores-germination and mycelium growth of Alternaria alternata and response to wounding and fungal attack. As much as we know, no genome-wide study of proteases together with proteinaceous PIs is reported in any of the sequenced genomes till now. Phylogenetic studies and domain analysis of proteases were carried out to understand the molecular evolution as well as gene and protein features. Structural analysis was carried out to explore the binding mode and affinity of PIs for cognate proteases and prolyl oligopeptidase protease with inhibitor ligand. In the study reported here, a significant number of proteases and PIs were identified in chickpea genome. The gene expression profiles of proteases and PIs in five different plant tissues revealed a differential expression pattern in more than one plant tissue. Molecular dynamics studies revealed the formation of stable complex owing to increased number of protein-ligand and inter and intramolecular protein-protein hydrogen bonds. The genome-wide identification, characterization, evolutionary understanding, gene expression, and structural analysis of proteases and PIs provide a framework for future analysis when defining their roles in stress response and developing a more stress tolerant variety of chickpea. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. SARS-Coronavirus ancestor's foot-prints in South-East Asian bat colonies and the refuge theory.

    Science.gov (United States)

    Gouilh, Meriadeg Ar; Puechmaille, Sébastien J; Gonzalez, Jean-Paul; Teeling, Emma; Kittayapong, Pattamaporn; Manuguerra, Jean-Claude

    2011-10-01

    One of the great challenges in the ecology of infectious diseases is to understand what drives the emergence of new pathogens including the relationship between viruses and their hosts. In the case of the emergence of SevereAcute Respiratory Syndrome Coronavirus (SARS-CoV), several studies have shown coronavirus diversity in bats as well as the existence of SARS-CoV infection in apparently healthy bats, suggesting that bats may be a crucial host in the genesis of this disease. To elucidate the biogeographic origin of SARS-CoV and investigate the role that bats played in its emergence, we amplified coronavirus sequences from bat species captured throughout Thailand and assessed the phylogenetic relationships to each other and to other published coronavirus sequences. To this end, RdRp sequence of Coronavirinae was targeted by RT-PCR in non-invasive samples from bats collected in Thailand. Two new coronaviruses were detected in two bat species: one Betacoronavirus in Hipposideros larvatus and one Alphacoronavirus in Hipposiderosarmiger. Interestingly, these viruses from South-East Asia are related to those previously detected in Africa (Betacoronavirus-b) or in Europe (Alphacoronavirus & Betacoronavirus-b). These findings illuminate the origin and the evolutionary history of the SARS-CoV group found in bats by pushing forward the hypothesis of a Betacoronavirus spill-over from Hipposideridae to Rhinolophidae and then from Rhinolophidae to civets and Human. All reported Betacoronaviruses-b (SARS-CoV group) of Hipposideridae and Rhinolophidae respectively cluster in two groups despite their broad geographic distribution and the sympatry of their hosts, which is in favor of an ancient and genetically independent evolution of Betacoronavirus-b clusters in these families. Moreover, despite its probable pathogenicity, we found that a Betacoronavirus-b can persistently infect a medium-sized hipposiderid bat colony. These findings illustrate the importance of the host

  3. Isolasi, Seleksi Dan Opttmasi Produksi Protease Daribeberapaisolat Bakteri*(isolation, Selection and Optimalization of Protease Production of Some Bacterial Isolates)

    OpenAIRE

    Naiola, Elidar; Widhyastuti, Nunuk

    2002-01-01

    Thirty-seven out of sixty-one bacterial isolates from various sources of samples were screened for protease production. The isolate of ISO PL3 could produce the highest enzyme activity, and it was used as a standard bacterial strain in this observation. For any reason,we implemented ISO PL2 to study the optimum condition for producing bacterial protease. Result shows that the maximum protease activity was obtained in a medium containing 100 gram of rice brand in a liter tofu liquid waste. The...

  4. Evidence for an Ancestral Association of Human Coronavirus 229E with Bats.

    Science.gov (United States)

    Corman, Victor Max; Baldwin, Heather J; Tateno, Adriana Fumie; Zerbinati, Rodrigo Melim; Annan, Augustina; Owusu, Michael; Nkrumah, Evans Ewald; Maganga, Gael Darren; Oppong, Samuel; Adu-Sarkodie, Yaw; Vallo, Peter; da Silva Filho, Luiz Vicente Ribeiro Ferreira; Leroy, Eric M; Thiel, Volker; van der Hoek, Lia; Poon, Leo L M; Tschapka, Marco; Drosten, Christian; Drexler, Jan Felix

    2015-12-01

    We previously showed that close relatives of human coronavirus 229E (HCoV-229E) exist in African bats. The small sample and limited genomic characterizations have prevented further analyses so far. Here, we tested 2,087 fecal specimens from 11 bat species sampled in Ghana for HCoV-229E-related viruses by reverse transcription-PCR (RT-PCR). Only hipposiderid bats tested positive. To compare the genetic diversity of bat viruses and HCoV-229E, we tested historical isolates and diagnostic specimens sampled globally over 10 years. Bat viruses were 5- and 6-fold more diversified than HCoV-229E in the RNA-dependent RNA polymerase (RdRp) and spike genes. In phylogenetic analyses, HCoV-229E strains were monophyletic and not intermixed with animal viruses. Bat viruses formed three large clades in close and more distant sister relationships. A recently described 229E-related alpaca virus occupied an intermediate phylogenetic position between bat and human viruses. According to taxonomic criteria, human, alpaca, and bat viruses form a single CoV species showing evidence for multiple recombination events. HCoV-229E and the alpaca virus showed a major deletion in the spike S1 region compared to all bat viruses. Analyses of four full genomes from 229E-related bat CoVs revealed an eighth open reading frame (ORF8) located at the genomic 3' end. ORF8 also existed in the 229E-related alpaca virus. Reanalysis of HCoV-229E sequences showed a conserved transcription regulatory sequence preceding remnants of this ORF, suggesting its loss after acquisition of a 229E-related CoV by humans. These data suggested an evolutionary origin of 229E-related CoVs in hipposiderid bats, hypothetically with camelids as intermediate hosts preceding the establishment of HCoV-229E. The ancestral origins of major human coronaviruses (HCoVs) likely involve bat hosts. Here, we provide conclusive genetic evidence for an evolutionary origin of the common cold virus HCoV-229E in hipposiderid bats by analyzing a

  5. Cloning and characterization of a novel cysteine protease gene ...

    Indian Academy of Sciences (India)

    PRAKASH KUMAR

    Cysteine proteases can be found in the animal and plant kingdoms as well as in some viruses and bacteria. They have been implemented in many ..... in developing resistance against pathogens and insects in other crops. Acknowledgments.

  6. Purification and characterization of a protease from Thermophilic ...

    African Journals Online (AJOL)

    AJB SERVER

    2006-10-19

    PAGE ... applications has been well recognized and it was ... One particular interest is the production of alkaline protease from bacillus for applications in detergent industry. (Ferrero et al., 1996; Manachini and Fortina, 1998;.

  7. Immune pressure analysis of protease and reverse transcriptase ...

    African Journals Online (AJOL)

    /dn) were analyzed for 33 HIV-1 subtype C protease (PR) and reverse transcriptase (RT) nucleotide sequences each from antiretroviral naïve South African chronically infected individuals. The ds/dn ratios were calculated using the ...

  8. A Protease Isolated from the Latex of Plumeria rubra Linn ...

    African Journals Online (AJOL)

    Erah

    purified protease was determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-. PAGE). ... by ammonium sulphate (40 - 60% w/v). The solution was kept .... chloride (88.1 %), silver nitrate (92.9 %), mercuric chloride ...

  9. Variable context Markov chains for HIV protease cleavage site prediction.

    Science.gov (United States)

    Oğul, Hasan

    2009-06-01

    Deciphering the knowledge of HIV protease specificity and developing computational tools for detecting its cleavage sites in protein polypeptide chain are very desirable for designing efficient and specific chemical inhibitors to prevent acquired immunodeficiency syndrome. In this study, we developed a generative model based on a generalization of variable order Markov chains (VOMC) for peptide sequences and adapted the model for prediction of their cleavability by certain proteases. The new method, called variable context Markov chains (VCMC), attempts to identify the context equivalence based on the evolutionary similarities between individual amino acids. It was applied for HIV-1 protease cleavage site prediction problem and shown to outperform existing methods in terms of prediction accuracy on a common dataset. In general, the method is a promising tool for prediction of cleavage sites of all proteases and encouraged to be used for any kind of peptide classification problem as well.

  10. Effect of Gastrointestinal Protease Digestion on Bioactivity of Marine Peptides

    DEFF Research Database (Denmark)

    Jensen, Ida-Johanne; Andersen, Lisa Lystbæk; Ossum, Carlo Gunnar

    2014-01-01

    executed without concerning subsequent digestion after intake and the aim of this work was hence to investigate how the in vitro antioxidative, antihypertensive and caspase activating activities of peptides are affected by digestion with gastrointestinal (GI) proteases. Five different fish protein...... hydrolysates were chosen to study the effect of in vitro digestion on bioactivity. The protein concentration decreased in all samples during digestion and the molecular weight distribution of the peptides shifted towards lower values. Thus, in vitro digestion with GI proteases resulted in a further degradation...... of the peptides obtained by hydrolysis. The antihypertensive effect increased in all samples after digestion with GI proteases whereas the antioxidative capacity decreased. The effect on the caspase activity depended on the proteases used in the preparation of hydrolysates. In conclusion, the caspase activity...

  11. [Analysis of salivary protease spectrum in chronic periodontitis].

    Science.gov (United States)

    Qian, Li; Xuedong, Zhou; Yaping, Fan; Tengyu, Yang; Songtao, Wu; Yu, Yu; Jiao, Chen; Ping, Zhang; Yun, Feng

    2017-02-01

    This study aimed to investigate the difference in salivary protease expression in patients with chronic periodontitis and normal individuals. The stimulating saliva in patients with chronic periodontitis and normal individuals were collected. Protein chip technology was adapted to analyze salivary protease spectrum. Among the 34 proteases in the chip, disintegrin and metalloproteinase (ADAM)8, matrix metalloproteinase (MMP)-8, MMP-12, neprilysin/CD10, and uridylyl phosphate adenosine/urokinase showed a significantly increased concentration in the saliva of chronic periodontitis patients compared with those in the saliva of normal individuals (Pchronic periodontitis patients and normal individuals significantly differed. Analysis of salivary protease spectrum is a potential clinical method to examine, diagnose, and monitor chronic periodontitis.

  12. Improvement of shelf life of soymilk using immobilized protease of Oerskovia xanthineolytica NCIM 2839

    OpenAIRE

    Sahoo, A. K.; Gaikwad, V. S.; Ranveer, R. C.; Dandge, P. B.; Waghmare, S. R.

    2016-01-01

    Protease enzyme has lot of commercial applications, so the cost-effective production of protease using sunflower oil seed waste was carried out from Oerskovia xanthineolyitca NCIM 2839. The maximum protease production was after 24?h of incubation with 2.5?% oil seed waste concentration. O. xanthineolytica was found to produce two proteases?P1 and P2. The proteases were purified using 60?% cold acetone precipitation and DEAE-cellulose ion exchange chromatography. SDS-PAGE revealed molecular we...

  13. Sequential Detection of Thermophilic Lipase and Protease by Zymography.

    Science.gov (United States)

    Kurz, Liliana; Hernández, Zully; Contreras, Lellys M; Wilkesman, Jeff

    2017-01-01

    Lipase and protease present in cell-free fractions of thermophilic Bacillus sp. cultures were analyzed by polyacrylamide gel (PAG) electrophoresis. After run, the gel is electrotransferred to another PAG copolymerized with glycerol tributyrate, olive oil, and gelatin. This multi-substrate gel was incubated first for lipase detection, until bands appeared, and then stained with Coomassie for protease detection. Advantages of this sequential procedure are the detection of two different enzyme activities on a single PAG, beside time and resource saving.

  14. Functional protease profiling for diagnosis of malignant disease.

    Science.gov (United States)

    Findeisen, Peter; Neumaier, Michael

    2012-01-01

    Clinical proteomic profiling by mass spectrometry (MS) aims at uncovering specific alterations within mass profiles of clinical specimens that are of diagnostic value for the detection and classification of various diseases including cancer. However, despite substantial progress in the field, the clinical proteomic profiling approaches have not matured into routine diagnostic applications so far. Their limitations are mainly related to high-abundance proteins and their complex processing by a multitude of endogenous proteases thus making rigorous standardization difficult. MS is biased towards the detection of low-molecular-weight peptides. Specifically, in serum specimens, the particular fragments of proteolytically degraded proteins are amenable to MS analysis. Proteases are known to be involved in tumour progression and tumour-specific proteases are released into the blood stream presumably as a result of invasive progression and metastasis. Thus, the determination of protease activity in clinical specimens from patients with malignant disease can offer diagnostic and also therapeutic options. The identification of specific substrates for tumour proteases in complex biological samples is challenging, but proteomic screens for proteases/substrate interactions are currently experiencing impressive progress. Such proteomic screens include peptide-based libraries, differential isotope labelling in combination with MS, quantitative degradomic analysis of proteolytically generated neo-N-termini, monitoring the degradation of exogenous reporter peptides with MS, and activity-based protein profiling. In the present article, we summarize and discuss the current status of proteomic techniques to identify tumour-specific protease-substrate interactions for functional protease profiling. Thereby, we focus on the potential diagnostic use of the respective approaches. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Molecular characterization of human coronaviruses and their circulation dynamics in Kenya, 2009-2012.

    Science.gov (United States)

    Sipulwa, Lenata A; Ongus, Juliette R; Coldren, Rodney L; Bulimo, Wallace D

    2016-02-01

    Human Coronaviruses (HCoV) are a common cause of respiratory illnesses and are responsible for considerable morbidity and hospitalization across all age groups especially in individuals with compromised immunity. There are six known species of HCoV: HCoV-229E, HCoV-NL63, HCoV-HKU1, HCoV-OC43, MERS-CoV and SARS-HCoV. Although studies have shown evidence of global distribution of HCoVs, there is limited information on their presence and distribution in Kenya. HCoV strains that circulated in Kenya were retrospectively diagnosed and molecularly characterized. A total of 417 nasopharyngeal specimens obtained between January 2009 and December 2012 from around Kenya were analyzed by a real time RT-PCR using HCoV-specific primers. HCoV-positive specimens were subsequently inoculated onto monolayers of LL-CMK2 cells. The isolated viruses were characterized by RT-PCR amplification and sequencing of the partial polymerase (pol) gene. The prevalence of HCoV infection was as follows: out of the 417 specimens, 35 (8.4 %) were positive for HCoV, comprising 10 (2.4 %) HCoV-NL63, 12 (2.9 %) HCoV-OC43, 9 (2.1 %) HCoV-HKU1, and 4 (1 %) HCoV-229E. The Kenyan HCoV strains displayed high sequence homology to the prototypes and contemporaneous strains. Evolution analysis showed that the Kenyan HCoV-OC43 and HCoV-NL63 isolates were under purifying selection. Phylogenetic evolutionary analyses confirmed the identities of three HCoV-HKU1, five HCoV-NL63, eight HCoV-OC43 and three HCoV-229E. There were yearly variations in the prevalence and circulation patterns of individual HCoVs in Kenya. This paper reports on the first molecular characterization of human Coronaviruses in Kenya, which play an important role in causing acute respiratory infections among children.

  16. Reverse genetics of SARS-related coronavirus using vaccinia virus-based recombination.

    Directory of Open Access Journals (Sweden)

    Sjoerd H E van den Worm

    Full Text Available Severe acute respiratory syndrome (SARS is a zoonotic disease caused by SARS-related coronavirus (SARS-CoV that emerged in 2002 to become a global health concern. Although the original outbreak was controlled by classical public health measures, there is a real risk that another SARS-CoV could re-emerge from its natural reservoir, either in its original form or as a more virulent or pathogenic strain; in which case, the virus would be difficult to control in the absence of any effective antiviral drugs or vaccines. Using the well-studied SARS-CoV isolate HKU-39849, we developed a vaccinia virus-based SARS-CoV reverse genetic system that is both robust and biosafe. The SARS-CoV genome was cloned in separate vaccinia virus vectors, (vSARS-CoV-5prime and vSARS-CoV-3prime as two cDNAs that were subsequently ligated to create a genome-length SARS-CoV cDNA template for in vitro transcription of SARS-CoV infectious RNA transcripts. Transfection of the RNA transcripts into permissive cells led to the recovery of infectious virus (recSARS-CoV. Characterization of the plaques produced by recSARS-CoV showed that they were similar in size to the parental SARS-CoV isolate HKU-39849 but smaller than the SARS-CoV isolate Frankfurt-1. Comparative analysis of replication kinetics showed that the kinetics of recSARS-CoV replication are similar to those of SARS-CoV Frankfurt-1, although the titers of virus released into the culture supernatant are approximately 10-fold less. The reverse genetic system was finally used to generate a recSARS-CoV reporter virus expressing Renilla luciferase in order to facilitate the analysis of SARS-CoV gene expression in human dendritic cells (hDCs. In parallel, a Renilla luciferase gene was also inserted into the genome of human coronavirus 229E (HCoV-229E. Using this approach, we demonstrate that, in contrast to HCoV-229E, SARS-CoV is not able to mediate efficient heterologous gene expression in hDCs.

  17. The Inflammatory Actions of Coagulant and Fibrinolytic Proteases in Disease

    Directory of Open Access Journals (Sweden)

    Michael Schuliga

    2015-01-01

    Full Text Available Aside from their role in hemostasis, coagulant and fibrinolytic proteases are important mediators of inflammation in diseases such as asthma, atherosclerosis, rheumatoid arthritis, and cancer. The blood circulating zymogens of these proteases enter damaged tissue as a consequence of vascular leak or rupture to become activated and contribute to extravascular coagulation or fibrinolysis. The coagulants, factor Xa (FXa, factor VIIa (FVIIa, tissue factor, and thrombin, also evoke cell-mediated actions on structural cells (e.g., fibroblasts and smooth muscle cells or inflammatory cells (e.g., macrophages via the proteolytic activation of protease-activated receptors (PARs. Plasmin, the principle enzymatic mediator of fibrinolysis, also forms toll-like receptor-4 (TLR-4 activating fibrin degradation products (FDPs and can release latent-matrix bound growth factors such as transforming growth factor-β (TGF-β. Furthermore, the proteases that convert plasminogen into plasmin (e.g., urokinase plasminogen activator evoke plasmin-independent proinflammatory actions involving coreceptor activation. Selectively targeting the receptor-mediated actions of hemostatic proteases is a strategy that may be used to treat inflammatory disease without the bleeding complications of conventional anticoagulant therapies. The mechanisms by which proteases of the coagulant and fibrinolytic systems contribute to extravascular inflammation in disease will be considered in this review.

  18. Characterizing Protease Specificity: How Many Substrates Do We Need?

    Directory of Open Access Journals (Sweden)

    Michael Schauperl

    Full Text Available Calculation of cleavage entropies allows to quantify, map and compare protease substrate specificity by an information entropy based approach. The metric intrinsically depends on the number of experimentally determined substrates (data points. Thus a statistical analysis of its numerical stability is crucial to estimate the systematic error made by estimating specificity based on a limited number of substrates. In this contribution, we show the mathematical basis for estimating the uncertainty in cleavage entropies. Sets of cleavage entropies are calculated using experimental cleavage data and modeled extreme cases. By analyzing the underlying mathematics and applying statistical tools, a linear dependence of the metric in respect to 1/n was found. This allows us to extrapolate the values to an infinite number of samples and to estimate the errors. Analyzing the errors, a minimum number of 30 substrates was found to be necessary to characterize substrate specificity, in terms of amino acid variability, for a protease (S4-S4' with an uncertainty of 5 percent. Therefore, we encourage experimental researchers in the protease field to record specificity profiles of novel proteases aiming to identify at least 30 peptide substrates of maximum sequence diversity. We expect a full characterization of protease specificity helpful to rationalize biological functions of proteases and to assist rational drug design.

  19. Pnserpin: A Novel Serine Protease Inhibitor from Extremophile Pyrobaculum neutrophilum

    Directory of Open Access Journals (Sweden)

    Huan Zhang

    2017-01-01

    Full Text Available Serine protease inhibitors (serpins are native inhibitors of serine proteases, constituting a large protein family with members spread over eukaryotes and prokaryotes. However, only very few prokaryotic serpins, especially from extremophiles, have been characterized to date. In this study, Pnserpin, a putative serine protease inhibitor from the thermophile Pyrobaculum neutrophilum, was overexpressed in Escherichia coli for purification and characterization. It irreversibly inhibits chymotrypsin-, trypsin-, elastase-, and subtilisin-like proteases in a temperature range from 20 to 100 °C in a concentration-dependent manner. The stoichiometry of inhibition (SI of Pnserpin for proteases decreases as the temperature increases, indicating that the inhibitory activity of Pnserpin increases with the temperature. SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis showed that Pnserpin inhibits proteases by forming a SDS-resistant covalent complex. Homology modeling and molecular dynamic simulations predicted that Pnserpin can form a stable common serpin fold. Results of the present work will help in understanding the structural and functional characteristics of thermophilic serpin and will broaden the current knowledge about serpins from extremophiles.

  20. Comparative Detection of Alkaline Protease Production in Exiguobacterium acetylicum

    International Nuclear Information System (INIS)

    Gomaa, O.M.; EI Shafey, H.M.

    2009-01-01

    Alkaline protease is one of the most important enzymes in industry, medicine, and research. In the present work, a comparative detection for alkaline protease activity was established for instant detection of enzyme activity. Eight different alkalophilic bacterial isolates were compared based on the clear zone they produced on skim milk agar. One strain gave an absolute clear zone in 16 hours and was used for alkaline protease detection. The result of Phenotypic identification using Biology Microlog 3 identified the isolate as Exiguobacterium acetylicum. The isolate under study showed slightly different characteristics from a known Exiguobacterium acetylicum strain. The isolate tolerated alkaline conditions up to ph 11, while good growth was evident at ph 7, the maximum alkaline protease activity was observed at ph 9 which reached up to 109.01 U/ml. The alkaline activity assay using alkaline protease enzyme assay were coordinating with those obtained by conductivity; there was a relevant decrease in conductivity at the maximum increase in enzyme activity, which proved the cell membrane conductivity has a close relation to alkaline protease production. This isolate has tolerated gamma radiation, the increase in dose (up to 4 Gy) gave wider clear zones in terms of diameter and this was relevant to the conductivity measurements

  1. Protease Production by Different Thermophilic Fungi

    Science.gov (United States)

    Macchione, Mariana M.; Merheb, Carolina W.; Gomes, Eleni; da Silva, Roberto

    A comparative study was carried out to evaluate protease production in solid-state fermentation (SSF) and submerged fermentation (SmF) by nine different thermophilic fungi — Thermoascus aurantiacus Miehe, Thermomyces lanuginosus, T. lanuginosus TO.03, Aspergillus flavus 1.2, Aspergillus sp. 13.33, Aspergillus sp. 13.34, Aspergillus sp. 13.35, Rhizomucor pusillus 13.36 and Rhizomucor sp. 13.37 — using substrates containing proteins to induce enzyme secretion. Soybean extract (soybean milk), soybean flour, milk powder, rice, and wheat bran were tested. The most satisfactory results were obtained when using wheat bran in SSF. The fungi that stood out in SSF were T. lanuginosus, T. lanuginosus TO.03, Aspergillus sp. 13.34, Aspergillus sp. 13.35, and Rhizomucor sp. 13.37, and those in SmF were T. aurantiacus, T. lanuginosus TO.03, and 13.37. In both fermentation systems, A. flavus 1.2 and R. pusillus 13.36 presented the lowest levels of proteolytic activity.

  2. Antibody proteases: induction of catalytic response.

    Science.gov (United States)

    Gabibov, A G; Friboulet, A; Thomas, D; Demin, A V; Ponomarenko, N A; Vorobiev, I I; Pillet, D; Paon, M; Alexandrova, E S; Telegin, G B; Reshetnyak, A V; Grigorieva, O V; Gnuchev, N V; Malishkin, K A; Genkin, D D

    2002-10-01

    Most of the data accumulated throughout the years on investigation of catalytic antibodies indicate that their production increases on the background of autoimmune abnormalities. The different approaches to induction of catalytic response toward recombinant gp120 HIV-1 surface protein in mice with various autoimmune pathologies are described. The peptidylphosphonate conjugate containing structural part of gp120 molecule is used for reactive immunization of NZB/NZW F1, MRL, and SJL mice. The specific modification of heavy and light chains of mouse autoantibodies with Val-Ala-Glu-Glu-Glu-Val-PO(OPh)2 reactive peptide was demonstrated. Increased proteolytic activity of polyclonal antibodies in SJL mice encouraged us to investigate the production of antigen-specific catalytic antibodies on the background of induced experimental autoimmune encephalomyelitis (EAE). The immunization of autoimmune-prone mice with the engineered fusions containing the fragments of gp120 and encephalitogenic epitope of myelin basic protein (MBP(89-104)) was made. The proteolytic activity of polyclonal antibodies isolated from the sera of autoimmune mice immunized by the described antigen was shown. Specific immune response of SJL mice to these antigens was characterized. Polyclonal antibodies purified from sera of the immunized animals revealed proteolytic activity. The antiidiotypic approach to raise the specific proteolytic antibody as an "internal image" of protease is described. The "second order" monoclonal antibodies toward subtilisin Carlsberg revealed pronounced proteolytic activity.

  3. Identification of Cysteine Proteases and Screening of Cysteine Protease Inhibitors in Biological Samples by a Two-Dimensional Gel System of Zymography and Reverse Zymography

    OpenAIRE

    Saitoh, Eiichi; Yamamoto, Shinya; Okamoto, Eishiro; Hayakawa, Yoshimi; Hoshino, Takashi; Sato, Ritsuko; Isemura, Satoko; Ohtsubo, Sadami; Taniguchi, Masayuki

    2007-01-01

    We have developed a two-dimensional (2D-) gel system of zymography and reverse zymography for the detection and characterization of proteases and protease inhibitors. Isoelectric focusing (IEF) agarose gels with pH gradients were employed for separation in the fi rst-dimension and sodium dodecyl sulfate (SDS)-polyacrylamide gel copolymerized with gelatin used for the second dimension. Proteases and protease inhibitors separated by IEF gel were applied on the second gel without trichloroacetic...

  4. Rapid detection of MERS coronavirus-like viruses in bats: pote1ntial for tracking MERS coronavirus transmission and animal origin.

    Science.gov (United States)

    Woo, Patrick C Y; Lau, Susanna K P; Chen, Yixin; Wong, Emily Y M; Chan, Kwok-Hung; Chen, Honglin; Zhang, Libiao; Xia, Ningshao; Yuen, Kwok-Yung

    2018-03-07

    Recently, we developed a monoclonal antibody-based rapid nucleocapsid protein detection assay for diagnosis of MERS coronavirus (MERS-CoV) in humans and dromedary camels. In this study, we examined the usefulness of this assay to detect other lineage C betacoronaviruses closely related to MERS-CoV in bats. The rapid MERS-CoV nucleocapsid protein detection assay was tested positive in 24 (88.9%) of 27 Tylonycteris bat CoV HKU4 (Ty-BatCoV-HKU4) RNA-positive alimentary samples of Tylonycteris pachypus and 4 (19.0%) of 21 Pipistrellus bat CoV HKU5 (Pi-BatCoV-HKU5) RNA-positive alimentary samples of Pipistrellus abramus. There was significantly more Ty-BatCoV-HKU4 RNA-positive alimentary samples than Pi-BatCoV-HKU5 RNA-positive alimentary samples that were tested positive by the rapid MERS-CoV nucleocapsid protein detection assay (P < 0.001 by Chi-square test). The rapid assay was tested negative in all 51 alimentary samples RNA-positive for alphacoronaviruses (Rhinolophus bat CoV HKU2, Myotis bat CoV HKU6, Miniopterus bat CoV HKU8 and Hipposideros batCoV HKU10) and 32 alimentary samples positive for lineage B (SARS-related Rhinolophus bat CoV HKU3) and lineage D (Rousettus bat CoV HKU9) betacoronaviruses. No significant difference was observed between the viral loads of Ty-BatCoV-HKU4/Pi-BatCoV-HKU5 RNA-positive alimentary samples that were tested positive and negative by the rapid test (Mann-Witney U test). The rapid MERS-CoV nucleocapsid protein detection assay is able to rapidly detect lineage C betacoronaviruses in bats. It detected significantly more Ty-BatCoV-HKU4 than Pi-BatCoV-HKU5 because MERS-CoV is more closely related to Ty-BatCoV-HKU4 than Pi-BatCoV-HKU5. This assay will facilitate rapid on-site mass screening of animal samples for ancestors of MERS-CoV and tracking transmission in the related bat species.

  5. Radioactive and enzymatic cloned cDNA probes for bovine enteric coronavirus detection by molecular hybridization

    International Nuclear Information System (INIS)

    Collomb, J.; Finance, C.; Alabouch, S.; Laporte, J.

    1992-01-01

    Genomic RNA of F15 strain bovine enteric coronavirus (BECV) was cloned in E. coli. Three clones (174, 160, PG 78), selected in the cDNA library, including a large portion of the nucleocapsid (N), matrix (M) and peplomeric (S) protein genes , were used as probes for a slot blot hybridization assay. Two probe labelling techniques were compared, radiolabelling with 32 P and enzymatic labelling through covalent linkage to peroxidase and chemiluminescence detection. The radioactive probe 174 detected as little as 1 to 3 pg of viral RNA, while the less sensitive enzymatic probe could not reveal more than 100 pg of RNA. No significant detection amplification was achieved when a mixture of the three probes was used. Probe 174 allowed specific identification for BECV. No hybridization was noticed either with rotaviruses or even with other antigenically unrelated members of the family Coronaviridae such as transmissible gastroenteritis virus. The test proved valid for detection of BECV in the supernatant of infected HRT-18 cells: genomic RNA could be detected after direct spotting of samples, but prior nucleic acid extraction after proteinase K treatment improved virus detection. BECV diagnosis in faecal samples using enzymatic probe was compared with conventional diagnostic methods. (authors)

  6. Nucleocapsid gene analysis from an imported case of Middle East respiratory syndrome coronavirus, Malaysia

    Directory of Open Access Journals (Sweden)

    Nor-Aziyah Mat-Rahim

    2015-07-01

    Full Text Available Objective: To describe the complete nucleocapsid (N gene region of Middle East respiratory syndrome coronavirus (MERS-CoV from imported case in Malaysia and the relations with human- and camel-derived MERS-CoV. Methods: Combination of throat and nasal swab specimens was subjected to viral RNA extraction. For screening, the extracted RNA was subjected to real-time RT-PCR targeting upstream of E gene, open reading frame 1b and open reading frame 1a. For confirmation, the RNA was subjected to RT-PCR targeting partial part of the RNA-dependent RNA polymerase and nucleocapsid, followed by amplification of complete N gene region. Nucleotide sequencing of the first Malaysian case of MERS-CoV was performed following the confirmation with real-time RT-PCR detection. Results: Initial analysis of partial RNA-dependent RNA polymerase and N gene revealed that the nucleotides had high similarity to Jeddah_1_2013 strain. Analysis of complete N gene region (1 242 nucleotides from the case showed high similarity and yet distinct to the nucleotide sequences of camel-derived MERS-CoV. Conclusions: From the finding, there are possibilities that the patient acquired the infection from zoonotic transmission from dromedary camels.

  7. Saracatinib Inhibits Middle East Respiratory Syndrome-Coronavirus Replication In Vitro

    Directory of Open Access Journals (Sweden)

    Jin Soo Shin

    2018-05-01

    Full Text Available The Middle East respiratory syndrome-coronavirus (MERS-CoV, first identified in Saudi Arabia, is an emerging zoonotic pathogen that causes severe acute respiratory illness in humans with a high fatality rate. Since its emergence, MERS-CoV continues to spread to countries outside of the Arabian Peninsula and gives rise to sporadic human infections following the entry of infected individuals to other countries, which can precipitate outbreaks similar to the one that occurred in South Korea in 2015. Current therapeutics against MERS-CoV infection have primarily been adapted from previous drugs used for the treatment of severe acute respiratory syndrome. In search of new potential drug candidates, we screened a library composed of 2334 clinically approved drugs and pharmacologically active compounds. The drug saracatinib, a potent inhibitor of Src-family of tyrosine kinases (SFK, was identified as an inhibitor of MERS-CoV replication in vitro. Our results suggest that saracatinib potently inhibits MERS-CoV at the early stages of the viral life cycle in Huh-7 cells, possibly through the suppression of SFK signaling pathways. Furthermore, saracatinib exhibited a synergistic effect with gemcitabine, an anticancer drug with antiviral activity against several RNA viruses. These data indicate that saracatinib alone or in combination with gemcitabine can provide a new therapeutic option for the treatment of MERS-CoV infection.

  8. Excretion and detection of SARS coronavirus and its nucleic acid from digestive system

    Science.gov (United States)

    Wang, Xin-Wei; Li, Jin-Song; Guo, Ting-Kai; Zhen, Bei; Kong, Qing-Xin; Yi, Bin; Li, Zhong; Song, Nong; Jin, Min; Wu, Xiao-Ming; Xiao, Wen-Jun; Zhu, Xiu-Mei; Gu, Chang-Qing; Yin, Jing; Wei, Wei; Yao, Wei; Liu, Chao; Li, Jian-Feng; Ou, Guo-Rong; Wang, Min-Nian; Fang, Tong-Yu; Wang, Gui-Jie; Qiu, Yao-Hui; Wu, Huai-Huan; Chao, Fu-Huan; Li, Jun-Wen

    2005-01-01

    AIM: To study whether severe acute respiratory syndrome coronavirus (SARS-CoV) could be excreted from digestive system. METHODS: Cell culture and semi-nested RT-PCR were used to detect SARS-CoV and its RNA from 21 stool and urine samples, and a kind of electropositive filter media particles was used to concentrate the virus in 10 sewage samples from two hospitals receiving SARS patients in Beijing in China. RESULTS: It was demonstrated that there was no live SARS-CoV in all samples collected, but the RNA of SARS-CoV could be detected in seven stool samples from SARS patients with any one of the symptoms of fever, malaise, cough, or dyspnea, in 10 sewage samples before disinfection and 3 samples after disinfection from the two hospitals. The RNA could not be detected in urine and stool samples from patients recovered from SARS. CONCLUSION: Nucleic acid of SARS-CoV can be excreted through the stool of patients into sewage system, and the possibility of SARS-CoV transmitting through digestive system cannot be excluded. PMID:16038039

  9. Absence of E protein arrests transmissible gastroenteritis coronavirus maturation in the secretory pathway

    International Nuclear Information System (INIS)

    Ortego, Javier; Ceriani, Juan E.; Patino, Cristina; Plana, Juan; Enjuanes, Luis

    2007-01-01

    A recombinant transmissible gastroenteritis coronavirus (rTGEV) in which E gene was deleted (rTGEV-ΔE) has been engineered. This deletion mutant only grows in cells expressing E protein (E + cells) indicating that E was an essential gene for TGEV replication. Electron microscopy studies of rTGEV-ΔE infected BHK-pAPN-E - cells showed that only immature intracellular virions were assembled. These virions were non-infectious and not secreted to the extracellular medium in BHK-pAPN-E - cells. RNA and protein composition analysis by RNase-gold and immunoelectron microscopy showed that rTGEV-ΔE virions contained RNA and also all the structural TGEV proteins, except the deleted E protein. Nevertheless, full virion maturation was blocked. Studies of the rTGEV-ΔE subcellular localization by confocal and immunoelectron microscopy in infected E - cells showed that in the absence of E protein virus trafficking was arrested in the intermediate compartment. Therefore, the absence of E protein in TGEV resulted in two actions, a blockade of virus trafficking in the membranes of the secretory pathway, and prevention of full virus maturation

  10. Murine Leukemia Virus (MLV)-based Coronavirus Spike-pseudotyped Particle Production and Infection

    Science.gov (United States)

    Millet, Jean Kaoru; Whittaker, Gary R.

    2016-01-01

    Viral pseudotyped particles (pp) are enveloped virus particles, typically derived from retroviruses or rhabdoviruses, that harbor heterologous envelope glycoproteins on their surface and a genome lacking essential genes. These synthetic viral particles are safer surrogates of native viruses and acquire the tropism and host entry pathway characteristics governed by the heterologous envelope glycoprotein used. They have proven to be very useful tools used in research with many applications, such as enabling the study of entry pathways of enveloped viruses and to generate effective gene-delivery vectors. The basis for their generation lies in the capacity of some viruses, such as murine leukemia virus (MLV), to incorporate envelope glycoproteins of other viruses into a pseudotyped virus particle. These can be engineered to contain reporter genes such as luciferase, enabling quantification of virus entry events upon pseudotyped particle infection with susceptible cells. Here, we detail a protocol enabling generation of MLV-based pseudotyped particles, using the Middle East respiratory syndrome coronavirus (MERS-CoV) spike (S) as an example of a heterologous envelope glycoprotein to be incorporated. We also describe how these particles are used to infect susceptible cells and to perform a quantitative infectivity readout by a luciferase assay. PMID:28018942

  11. Factors Influencing Emergency Nurses' Burnout During an Outbreak of Middle East Respiratory Syndrome Coronavirus in Korea.

    Science.gov (United States)

    Kim, Ji Soo; Choi, Jeong Sil

    2016-12-01

    Emergency department (ED) nurses suffer from persistent stress after experiencing the traumatic event of exposure to Middle East respiratory syndrome coronavirus (MERS-CoV), which can subsequently lead to burnout. This study aimed to assess ED nurses' burnout level during an outbreak of MERS-CoV and to identify influencing factors in order to provide basic information for lowering and preventing the level of burnout. Study participants were ED nurses working in eight hospitals designated for treating MERS-CoV-infected patients in Korea. We performed multiple regression analysis to explore the factors influencing burnout. The ED nurses' burnout was affected by job stress (β=0.59, pburnout. ED nurses taking care of MERS-CoV-infected patients should be aware that burnout is higher for nurses in their divisions than nurses in other hospital departments and that job stress is the biggest influential factor of burnout. To be ready for the outbreak of emerging contagious diseases such as MERS-CoV, efforts and preparations should be made to reduce burnout. Job stress should be managed and resolved. Working conditions for mitigating job stress and systematic stress management programs should be provided, and hospital resources for the treatment of MERS-CoV need to be reinforced. Moreover, promoting support from family and friends is required. Copyright © 2016. Published by Elsevier B.V.

  12. Peptide Mimicrying Between SARS Coronavirus Spike Protein and Human Proteins Reacts with SARS Patient Serum

    Directory of Open Access Journals (Sweden)

    K.-Y. Hwa

    2008-01-01

    Full Text Available Molecular mimicry, defined as similar structures shared by molecules from dissimilar genes or proteins, is a general strategy used by pathogens to infect host cells. Severe acute respiratory syndrome (SARS is a new human respiratory infectious disease caused by SARS coronavirus (SARS-CoV. The spike (S protein of SARS-CoV plays an important role in the virus entry into a cell. In this study, eleven synthetic peptides from the S protein were selected based on its sequence homology with human proteins. Two of the peptides D07 (residues 927–937 and D08 (residues 942–951 were recognized by the sera of SARS patients. Murine hyperimmune sera against these peptides bound to proteins of human lung epithelial cells A549. Another peptide D10 (residues 490–502 stimulated A549 to proliferate and secrete IL-8. The present results suggest that the selected S protein regions, which share sequence homology with human proteins, may play important roles in SARS-CoV infection.

  13. Immune responses against SARS-coronavirus nucleocapsid protein induced by DNA vaccine

    International Nuclear Information System (INIS)

    Zhao Ping; Cao Jie; Zhao Lanjuan; Qin Zhaolin; Ke Jinshan; Pan Wei; Ren Hao; Yu Jianguo; Qi Zhongtian

    2005-01-01

    The nucleocapsid (N) protein of SARS-coronavirus (SARS-CoV) is the key protein for the formation of the helical nucleocapsid during virion assembly. This protein is believed to be more conserved than other proteins of the virus, such as spike and membrane glycoprotein. In this study, the N protein of SARS-CoV was expressed in Escherichia coli DH5α and identified with pooled sera from patients in the convalescence phase of SARS. A plasmid pCI-N, encoding the full-length N gene of SARS-CoV, was constructed. Expression of the N protein was observed in COS1 cells following transfection with pCI-N. The immune responses induced by intramuscular immunization with pCI-N were evaluated in a murine model. Serum anti-N immunoglobulins and splenocytes proliferative responses against N protein were observed in immunized BALB/c mice. The major immunoglobulin G subclass recognizing N protein was immunoglobulin G2a, and stimulated splenocytes secreted high levels of gamma interferon and IL-2 in response to N protein. More importantly, the immunized mice produced strong delayed-type hypersensitivity (DTH) and CD8 + CTL responses to N protein. The study shows that N protein of SARS-CoV not only is an important B cell immunogen, but also can elicit broad-based cellular immune responses. The results indicate that the N protein may be of potential value in vaccine development for specific prophylaxis and treatment against SARS

  14. Antibodies against MERS coronavirus in dromedary camels, United Arab Emirates, 2003 and 2013.

    Science.gov (United States)

    Meyer, Benjamin; Müller, Marcel A; Corman, Victor M; Reusken, Chantal B E M; Ritz, Daniel; Godeke, Gert-Jan; Lattwein, Erik; Kallies, Stephan; Siemens, Artem; van Beek, Janko; Drexler, Jan F; Muth, Doreen; Bosch, Berend-Jan; Wernery, Ulrich; Koopmans, Marion P G; Wernery, Renate; Drosten, Christian

    2014-04-01

    Middle East respiratory syndrome coronavirus (MERS-CoV) has caused an ongoing outbreak of severe acute respiratory tract infection in humans in the Arabian Peninsula since 2012. Dromedary camels have been implicated as possible viral reservoirs. We used serologic assays to analyze 651 dromedary camel serum samples from the United Arab Emirates; 151 of 651 samples were obtained in 2003, well before onset of the current epidemic, and 500 serum samples were obtained in 2013. Recombinant spike protein-specific immunofluorescence and virus neutralization tests enabled clear discrimination between MERS-CoV and bovine CoV infections. Most (632/651, 97.1%) camels had antibodies against MERS-CoV. This result included all 151 serum samples obtained in 2003. Most (389/651, 59.8%) serum samples had MERS-CoV-neutralizing antibody titers >1,280. Dromedary camels from the United Arab Emirates were infected at high rates with MERS-CoV or a closely related, probably conspecific, virus long before the first human MERS cases.

  15. Crystallization and preliminary X-ray diffraction analysis of Nsp15 from SARS coronavirus

    International Nuclear Information System (INIS)

    Ricagno, Stéfano; Coutard, Bruno; Grisel, Sacha; Brémond, Nicolas; Dalle, Karen; Tocque, Fabienne; Campanacci, Valérie; Lichière, Julie; Lantez, Violaine; Debarnot, Claire; Cambillau, Christian; Canard, Bruno; Egloff, Marie-Pierre

    2006-01-01

    Crystals of Nsp15 from the aetiological agent of SARS have been grown at room temperature. Crystals have cubic symmetry and diffract to a maximum resolution of 2.7 Å. The non-structural protein Nsp15 from the aetiological agent of SARS (severe acute respiratory syndrome) has recently been characterized as a uridine-specific endoribonuclease. This enzyme plays an essential role in viral replication and transcription since a mutation in the related H229E human coronavirus nsp15 gene can abolish viral RNA synthesis. SARS full-length Nsp15 (346 amino acids) has been cloned and expressed in Escherichia coli with an N-terminal hexahistidine tag and has been purified to homogeneity. The protein was subsequently crystallized using PEG 8000 or 10 000 as precipitants. Small cubic crystals of the apoenzyme were obtained from 100 nl nanodrops. They belong to space group P4 1 32 or P4 3 32, with unit-cell parameters a = b = c = 166.8 Å. Diffraction data were collected to a maximum resolution of 2.7 Å

  16. Two deletion variants of Middle East respiratory syndrome coronavirus found in a patient with characteristic symptoms.

    Science.gov (United States)

    Xie, Qian; Cao, Yujuan; Su, Juan; Wu, Jie; Wu, Xianbo; Wan, Chengsong; He, Mingliang; Ke, Changwen; Zhang, Bao; Zhao, Wei

    2017-08-01

    Significant sequence variation of Middle East respiratory syndrome coronavirus (MERS CoV) has never been detected since it was first reported in 2012. A MERS patient came from Korea to China in late May 2015. The patient was 44 years old and had symptoms including high fever, dry cough with a little phlegm, and shortness of breath, which are roughly consistent with those associated with MERS, and had had close contact with individuals with confirmed cases of MERS.After one month of therapy with antiviral, anti-infection, and immune-enhancing agents, the patient recovered in the hospital and was discharged. A nasopharyngeal swab sample was collected for direct sequencing, which revealed two deletion variants of MERS CoV. Deletions of 414 and 419 nt occurred between ORF5 and the E protein, resulting in a partial protein fusion or truncation of ORF5 and the E protein. Functional analysis by bioinformatics and comparison to previous studies implied that the two variants might be defective in their ability to package MERS CoV. However, the mechanism of how these deletions occurred and what effects they have need to be further investigated.

  17. Radioactive and enzymatic cloned cDNA probes for bovine enteric coronavirus detection by molecular hybridization

    Energy Technology Data Exchange (ETDEWEB)

    Collomb, J; Finance, C; Alabouch, S [Lab. de Microbiologie Moleculaire, Faculte des Sciences Pharmaceutiques et Biologiques, Univ. de Nancy I, Nancy (France); Laporte, J [Station de Virologie et d' Immunologie Moleculaires, INRA, Jouy-en-Josas (France)

    1992-01-01

    Genomic RNA of F15 strain bovine enteric coronavirus (BECV) was cloned in E. coli. Three clones (174, 160, PG 78), selected in the cDNA library, including a large portion of the nucleocapsid (N), matrix (M) and peplomeric (S) protein genes , were used as probes for a slot blot hybridization assay. Two probe labelling techniques were compared, radiolabeled with [sup 32]P and enzymatic labeled through covalent linkage to peroxidase for chemiluminescence detection. The radioactive probe 174 detected as little as 1-3 pg of viral RNA, while the less sensitive enzymatic probe could not reveal more than 100 pg of RNA. No significant detection amplification was achieved when a mixture of the three probes was used. Probe 174 allowed specific identification for BECV. No hybridization was noticed either with rotaviruses or even with other antigenically unrelated members of the family Coronaviridae such as transmissible gastroenteritis virus. The test proved valid for detection of BECV in the supernatant of infected HRT-18 cells: genomic RNA could be detected after direct spotting of samples, but prior nucleic acid extraction after proteinase K treatment improved virus detection. BECV diagnosis in fecal samples using enzymatic probe was compared with conventional diagnostic methods. (authors).

  18. The Characteristics of Middle Eastern Respiratory Syndrome Coronavirus Transmission Dynamics in South Korea.

    Science.gov (United States)

    Kim, Yunhwan; Lee, Sunmi; Chu, Chaeshin; Choe, Seoyun; Hong, Saeme; Shin, Youngseo

    2016-02-01

    The outbreak of Middle Eastern respiratory syndrome coronavirus (MERS-CoV) was one of the major events in South Korea in 2015. In particular, this study pays attention to formulating a mathematical model for MERS transmission dynamics and estimating transmission rates. Incidence data of MERS-CoV from the government authority was analyzed for the first aim and a mathematical model was built and analyzed for the second aim of the study. A mathematical model for MERS-CoV transmission dynamics is used to estimate the transmission rates in two periods due to the implementation of intensive interventions. Using the estimates of the transmission rates, the basic reproduction number was estimated in two periods. Due to the superspreader, the basic reproduction number was very large in the first period; however, the basic reproduction number of the second period has reduced significantly after intensive interventions. It turned out to be the intensive isolation and quarantine interventions that were the most critical factors that prevented the spread of the MERS outbreak. The results are expected to be useful to devise more efficient intervention strategies in the future.

  19. An Opportunistic Pathogen Afforded Ample Opportunities: Middle East Respiratory Syndrome Coronavirus

    Directory of Open Access Journals (Sweden)

    Ian M. Mackay

    2017-12-01

    Full Text Available The human coronaviruses (CoV include HCoV-229E, HCoV-OC43, HCoV-NL63, and HCoV-HKU1, some of which have been known for decades. The severe acute respiratory syndrome (SARS CoV briefly emerged into the human population but was controlled. In 2012, another novel severely human pathogenic CoV—the Middle East Respiratory Syndrome (MERS-CoV—was identified in the Kingdom of Saudi Arabia; 80% of over 2000 human cases have been recorded over five years. Targeted research remains key to developing control strategies for MERS-CoV, a cause of mild illness in its camel reservoir. A new therapeutic toolbox being developed in response to MERS is also teaching us more about how CoVs cause disease. Travel-related cases continue to challenge the world’s surveillance and response capabilities, and more data are needed to understand unexplained primary transmission. Signs of genetic change have been recorded, but it remains unclear whether there is any impact on clinical disease. How camels came to carry the virus remains academic to the control of MERS. To date, human-to-human transmission has been inefficient, but virus surveillance, characterisation, and reporting are key to responding to any future change. MERS-CoV is not currently a pandemic threat; it is spread mainly with the aid of human habit and error.

  20. Saracatinib Inhibits Middle East Respiratory Syndrome-Coronavirus Replication In Vitro.

    Science.gov (United States)

    Shin, Jin Soo; Jung, Eunhye; Kim, Meehyein; Baric, Ralph S; Go, Yun Young

    2018-05-24

    The Middle East respiratory syndrome-coronavirus (MERS-CoV), first identified in Saudi Arabia, is an emerging zoonotic pathogen that causes severe acute respiratory illness in humans with a high fatality rate. Since its emergence, MERS-CoV continues to spread to countries outside of the Arabian Peninsula and gives rise to sporadic human infections following the entry of infected individuals to other countries, which can precipitate outbreaks similar to the one that occurred in South Korea in 2015. Current therapeutics against MERS-CoV infection have primarily been adapted from previous drugs used for the treatment of severe acute respiratory syndrome. In search of new potential drug candidates, we screened a library composed of 2334 clinically approved drugs and pharmacologically active compounds. The drug saracatinib, a potent inhibitor of Src-family of tyrosine kinases (SFK), was identified as an inhibitor of MERS-CoV replication in vitro. Our results suggest that saracatinib potently inhibits MERS-CoV at the early stages of the viral life cycle in Huh-7 cells, possibly through the suppression of SFK signaling pathways. Furthermore, saracatinib exhibited a synergistic effect with gemcitabine, an anticancer drug with antiviral activity against several RNA viruses. These data indicate that saracatinib alone or in combination with gemcitabine can provide a new therapeutic option for the treatment of MERS-CoV infection.

  1. Middle East respiratory syndrome coronavirus specific antibodies in naturally exposed Israeli llamas, alpacas and camels

    Directory of Open Access Journals (Sweden)

    Dan David

    2018-06-01

    Full Text Available Thus far, no human MERS-CoV infections have been reported from Israel. Evidence for the circulation of MERS-CoV in dromedaries has been reported from almost all the countries of the Middle East, except Israel. Therefore, we aimed to analyze MERS-CoV infection in Israeli camelids, sampled between 2012 and 2017. A total of 411 camels, 102 alpacas and 19 llamas' sera were tested for the presence of antibodies to MERS-CoV. Our findings indicate a lower MERS-CoV seropositivity among Israeli dromedaries than in the surrounding countries, and for the first time naturally infected llamas were identified. In addition, nasal swabs of 661 camels, alpacas and lamas, obtained from January 2015 to December 2017, were tested for the presence of MERS-CoV RNA. All nasal swabs were negative, indicating no evidence for MERS-CoV active circulation in these camelids during that time period. Keywords: MERS coronavirus, Antibodies, Israel, Dromedary camels, Llamas, Alpacas

  2. Severe respiratory illness associated with a novel coronavirus--Saudi Arabia and Qatar, 2012.

    Science.gov (United States)

    2012-10-12

    CDC is working closely with the World Health Organization (WHO) and other partners to better understand the public health risk presented by a recently detected, novel coronavirus. This virus has been identified in two patients, both previously healthy adults who suffered severe respiratory illness. The first patient, a man aged 60 years from Saudi Arabia, was hospitalized in June 2012 and died; the second patient, a man aged 49 years from Qatar with onset of symptoms in September 2012 was transported to the United Kingdom for intensive care. He remains hospitalized on life support with both pulmonary and renal failure. Person-to-person or health-care-associated transmission has not been identified to date. Interim case definitions based on acute respiratory illness and travel history were issued by WHO on September 29 and include criteria for "patient under investigation," "probable case," and "confirmed case". This information is current as of October 4. Updates on the investigation and the WHO case definition are available at http://www.who.int/csr/don/en/index.html.

  3. Crystallization and preliminary X-ray diffraction analysis of Nsp15 from SARS coronavirus

    Energy Technology Data Exchange (ETDEWEB)

    Ricagno, Stéfano; Coutard, Bruno; Grisel, Sacha; Brémond, Nicolas; Dalle, Karen; Tocque, Fabienne; Campanacci, Valérie; Lichière, Julie; Lantez, Violaine; Debarnot, Claire; Cambillau, Christian; Canard, Bruno; Egloff, Marie-Pierre, E-mail: marie-pierre.egloff@afmb.univ-mrs.fr [Centre National de la Recherche Scientifique and Universités d’Aix-Marseille I et II, UMR 6098, Architecture et Fonction des Macromolécules Biologiques, Ecole Supérieure d’Ingénieurs de Luminy-Case 925, 163 Avenue de Luminy, 13288 Marseille CEDEX 9 (France)

    2006-04-01

    Crystals of Nsp15 from the aetiological agent of SARS have been grown at room temperature. Crystals have cubic symmetry and diffract to a maximum resolution of 2.7 Å. The non-structural protein Nsp15 from the aetiological agent of SARS (severe acute respiratory syndrome) has recently been characterized as a uridine-specific endoribonuclease. This enzyme plays an essential role in viral replication and transcription since a mutation in the related H229E human coronavirus nsp15 gene can abolish viral RNA synthesis. SARS full-length Nsp15 (346 amino acids) has been cloned and expressed in Escherichia coli with an N-terminal hexahistidine tag and has been purified to homogeneity. The protein was subsequently crystallized using PEG 8000 or 10 000 as precipitants. Small cubic crystals of the apoenzyme were obtained from 100 nl nanodrops. They belong to space group P4{sub 1}32 or P4{sub 3}32, with unit-cell parameters a = b = c = 166.8 Å. Diffraction data were collected to a maximum resolution of 2.7 Å.

  4. Characterization of an Immunodominant Epitope in the Endodomain of the Coronavirus Membrane Protein

    Directory of Open Access Journals (Sweden)

    Hui Dong

    2016-12-01

    Full Text Available The coronavirus membrane (M protein acts as a dominant immunogen and is a major player in virus assembly. In this study, we prepared two monoclonal antibodies (mAbs; 1C3 and 4C7 directed against the transmissible gastroenteritis virus (TGEV M protein. The 1C3 and 4C7 mAbs both reacted with the native TGEV M protein in western blotting and immunofluorescence (IFA assays. Two linear epitopes, 243YSTEART249 (1C3 and 243YSTEARTDNLSEQEKLLHMV262 (4C7, were identified in the endodomain of the TGEV M protein. The 1C3 mAb can be used for the detection of the TGEV M protein in different assays. An IFA method for the detection of TGEV M protein was optimized using mAb 1C3. Furthermore, the ability of the epitope identified in this study to stimulate antibody production was also evaluated. An immunodominant epitope in the TGEV membrane protein endodomain was identified. The results of this study have implications for further research on TGEV replication.

  5. Structural and Functional Analyses of the Severe Acute Respiratory Syndrome Coronavirus Endoribonuclease Nsp15

    Energy Technology Data Exchange (ETDEWEB)

    Bhardwaj, Kanchan; Palaninathan, Satheesh; Alcantara, Joanna Maria Ortiz; Yi, Lillian Li; Guarino, Linda; Sacchettini, James C.; Kao, C. Cheng (TAM)

    2008-03-31

    The severe acute respiratory syndrome (SARS) coronavirus encodes several RNA-processing enzymes that are unusual for RNA viruses, including Nsp15 (nonstructural protein 15), a hexameric endoribonuclease that preferentially cleaves 3' of uridines. We solved the structure of a catalytically inactive mutant version of Nsp15, which was crystallized as a hexamer. The structure contains unreported flexibility in the active site of each subunit. Substitutions in the active site residues serine 293 and proline 343 allowed Nsp15 to cleave at cytidylate, whereas mutation of leucine 345 rendered Nsp15 able to cleave at purines as well as pyrimidines. Mutations that targeted the residues involved in subunit interactions generally resulted in the formation of catalytically inactive monomers. The RNA-binding residues were mapped by a method linking reversible cross-linking, RNA affinity purification, and peptide fingerprinting. Alanine substitution of several residues in the RNA-contacting portion of Nsp15 did not affect hexamer formation but decreased the affinity of RNA binding and reduced endonuclease activity. This suggests a model for Nsp15 hexamer interaction with RNA.

  6. Protein-Protein Interactions of Viroporins in Coronaviruses and Paramyxoviruses: New Targets for Antivirals?

    Directory of Open Access Journals (Sweden)

    Jaume Torres

    2015-06-01

    Full Text Available Viroporins are members of a rapidly growing family of channel-forming small polypeptides found in viruses. The present review will be focused on recent structural and protein-protein interaction information involving two viroporins found in enveloped viruses that target the respiratory tract; (i the envelope protein in coronaviruses and (ii the small hydrophobic protein in paramyxoviruses. Deletion of these two viroporins leads to viral attenuation in vivo, whereas data from cell culture shows involvement in the regulation of stress and inflammation. The channel activity and structure of some representative members of these viroporins have been recently characterized in some detail. In addition, searches for protein-protein interactions using yeast-two hybrid techniques have shed light on possible functional roles for their exposed cytoplasmic domains. A deeper analysis of these interactions should not only provide a more complete overview of the multiple functions of these viroporins, but also suggest novel strategies that target protein-protein interactions as much needed antivirals. These should complement current efforts to block viroporin channel activity.

  7. Identification of an archaeal presenilin-like intramembrane protease.

    Science.gov (United States)

    Torres-Arancivia, Celia; Ross, Carolyn M; Chavez, Jose; Assur, Zahra; Dolios, Georgia; Mancia, Filippo; Ubarretxena-Belandia, Iban

    2010-09-29

    The GXGD-type diaspartyl intramembrane protease, presenilin, constitutes the catalytic core of the γ-secretase multi-protein complex responsible for activating critical signaling cascades during development and for the production of β-amyloid peptides (Aβ) implicated in Alzheimer's disease. The only other known GXGD-type diaspartyl intramembrane proteases are the eukaryotic signal peptide peptidases (SPPs). The presence of presenilin-like enzymes outside eukaryots has not been demonstrated. Here we report the existence of presenilin-like GXGD-type diaspartyl intramembrane proteases in archaea. We have employed in vitro activity assays to show that MCMJR1, a polytopic membrane protein from the archaeon Methanoculleus marisnigri JR1, is an intramembrane protease bearing the signature YD and GXGD catalytic motifs of presenilin-like enzymes. Mass spectrometry analysis showed MCMJR1 could cleave model intramembrane protease substrates at several sites within their transmembrane region. Remarkably, MCMJR1 could also cleave substrates derived from the β-amyloid precursor protein (APP) without the need of protein co-factors, as required by presenilin. Two distinct cleavage sites within the transmembrane domain of APP could be identified, one of which coincided with Aβ40, the predominant site processed by γ-secretase. Finally, an established presenilin and SPP transition-state analog inhibitor could inhibit MCMJR1. Our findings suggest that a primitive GXGD-type diaspartyl intramembrane protease from archaea can recapitulate key biochemical properties of eukaryotic presenilins and SPPs. MCMJR1 promises to be a more tractable, simpler system for in depth structural and mechanistic studies of GXGD-type diaspartyl intramembrane proteases.

  8. Identification of an archaeal presenilin-like intramembrane protease.

    Directory of Open Access Journals (Sweden)

    Celia Torres-Arancivia

    Full Text Available BACKGROUND: The GXGD-type diaspartyl intramembrane protease, presenilin, constitutes the catalytic core of the γ-secretase multi-protein complex responsible for activating critical signaling cascades during development and for the production of β-amyloid peptides (Aβ implicated in Alzheimer's disease. The only other known GXGD-type diaspartyl intramembrane proteases are the eukaryotic signal peptide peptidases (SPPs. The presence of presenilin-like enzymes outside eukaryots has not been demonstrated. Here we report the existence of presenilin-like GXGD-type diaspartyl intramembrane proteases in archaea. METHODOLOGY AND PRINCIPAL FINDINGS: We have employed in vitro activity assays to show that MCMJR1, a polytopic membrane protein from the archaeon Methanoculleus marisnigri JR1, is an intramembrane protease bearing the signature YD and GXGD catalytic motifs of presenilin-like enzymes. Mass spectrometry analysis showed MCMJR1 could cleave model intramembrane protease substrates at several sites within their transmembrane region. Remarkably, MCMJR1 could also cleave substrates derived from the β-amyloid precursor protein (APP without the need of protein co-factors, as required by presenilin. Two distinct cleavage sites within the transmembrane domain of APP could be identified, one of which coincided with Aβ40, the predominant site processed by γ-secretase. Finally, an established presenilin and SPP transition-state analog inhibitor could inhibit MCMJR1. CONCLUSIONS AND SIGNIFICANCE: Our findings suggest that a primitive GXGD-type diaspartyl intramembrane protease from archaea can recapitulate key biochemical properties of eukaryotic presenilins and SPPs. MCMJR1 promises to be a more tractable, simpler system for in depth structural and mechanistic studies of GXGD-type diaspartyl intramembrane proteases.

  9. The roles of transportation and transportation hubs in the propagation of influenza and coronaviruses: a systematic review.

    Science.gov (United States)

    Browne, Annie; Ahmad, Sacha St-Onge; Beck, Charles R; Nguyen-Van-Tam, Jonathan S

    2016-01-01

    Respiratory viruses spread in humans across wide geographical areas in short periods of time, resulting in high levels of morbidity and mortality. We undertook a systematic review to assess the evidence that air, ground and sea mass transportation systems or hubs are associated with propagating influenza and coronaviruses. Healthcare databases and sources of grey literature were searched using pre-defined criteria between April and June 2014. Two reviewers screened all identified records against the protocol, undertook risk of bias assessments and extracted data using a piloted form. Results were analysed using a narrative synthesis. Forty-one studies met the eligibility criteria. Risk of bias was high in the observational studies, moderate to high in the reviews and moderate to low in the modelling studies. In-flight influenza transmission was identified substantively on five flights with up to four confirmed and six suspected secondary cases per affected flight. Five studies highlighted the role of air travel in accelerating influenza spread to new areas. Influenza outbreaks aboard cruise ships affect 2-7% of passengers. Influenza transmission events have been observed aboard ground transport vehicles. High heterogeneity between studies and the inability to exclude other sources of infection means that the risk of influenza transmission from an index case to other passengers cannot be accurately quantified. A paucity of evidence was identified describing severe acute respiratory syndrome coronavirus and Middle East respiratory syndrome coronavirus transmission events associated with transportation systems or hubs. Air transportation appears important in accelerating and amplifying influenza propagation. Transmission occurs aboard aeroplanes, at the destination and possibly at airports. Control measures to prevent influenza transmission on cruise ships are needed to reduce morbidity and mortality. There is no recent evidence of sea transport accelerating influenza

  10. Diversity of both the cultivable protease-producing bacteria and bacterial extracellular proteases in the coastal sediments of King George Island, Antarctica.

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    Ming-Yang Zhou

    Full Text Available Protease-producing bacteria play a vital role in degrading sedimentary organic nitrogen. However, the diversity of these bacteria and their extracellular proteases in most regions remain unknown. In this paper, the diversity of the cultivable protease-producing bacteria and of bacterial extracellular proteases in the sediments of Maxwell Bay, King George Island, Antarctica was investigated. The cultivable protease-producing bacteria reached 10(5 cells/g in all 8 sediment samples. The cultivated protease-producing bacteria were mainly affiliated with the phyla Actinobacteria, Firmicutes, Bacteroidetes, and Proteobacteria, and the predominant genera were Bacillus (22.9%, Flavobacterium (21.0% and Lacinutrix (16.2%. Among these strains, Pseudoalteromonas and Flavobacteria showed relatively high protease production. Inhibitor analysis showed that nearly all the extracellular proteases from the bacteria were serine proteases or metalloproteases. These results begin to address the diversity of protease-producing bacteria and bacterial extracellular proteases in the sediments of the Antarctic Sea.

  11. Characterization and milk coagulating properties of Cynanchum otophyllum Schneid. proteases.

    Science.gov (United States)

    Luo, Jie; Xiao, Chen; Zhang, Hao; Ren, Fazheng; Lei, Xingen; Yang, Zibiao; Yu, Zhengquan

    2018-04-01

    The herbaceous plant Cynanchum otophyllum Schneid. is widely used as a milk coagulant to make a Chinese traditional milk product, milk cake. However, the milk-clotting compounds and their mechanism remain unclear. In this study, crude proteases were extracted from the dried leaves of Cynanchum otophyllum Schneid. using citric acid-phosphate buffer and then partially purified by weak anion exchange chromatography. Two proteases, QA and QC, with molecular weights of 14 and 27 kDa, respectively, were shown to exhibit milk-clotting activity. A study of the effects of pH and temperature on the milk-clotting activity and proteolytic activity of the proteases showed that they exhibited good pH stability from pH 5.5 to 7.5 and good thermal stability at temperatures from 50 to 70°C. The QA and QC were the cysteine proteases, able to hydrolyze β-casein and κ-casein completely, and α-casein partially. The cleavage site on κ-casein determined by Orbitrap (Thermo Fisher Scientific, San Jose, CA) analysis showed that QA and QC could cleave κ-casein at Ser132-Thr133. Overall, the results suggest that the Cynanchum otophyllum Schneid. proteases are a promising milk-clotting enzyme that could be used for manufacturing milk cake and cheese. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  12. Cysteine Protease (Capparin from Capsules of Caper (Capparis spinosa

    Directory of Open Access Journals (Sweden)

    Yasar Demir

    2008-01-01

    Full Text Available Proteases are enzymes that perform very important functions in organisms and are used for a variety of objectives in vitro. In recent years, proteases have been used for clinical, pharmaceutical (alimentary digestion, anti-inflammatory, etc. and industrial applications (cheese production, meat tenderizing, leather tanning. In this research, a protease has been purified from capsules of caper (Capparis spinosa and characterized. Caper plants have been used for food and medicine since ancient times. The plant grows abundantly in certain regions of Turkey. Ammonium sulphate fractionation and a CM Sephadex column were used for purification of the enzyme. The purification enzyme has an optimum pH=5.0 and its optimum temperature was 60 °C. The vmax and Km values determined by Lineweaver-Burk graphics were 1.38 μg/(L·min and 0.88 μg/L, respectively. The purification degree and the molecular mass of the enzyme (46 kDa were determined by SDS-PAGE and gel filtration chromatography. It was investigated whether the purified and characterized protease could cause milk to congeal or digest chicken and cow meat. The results show that protease can be used for industrial production.

  13. Detection of protease activity in cells and animals.

    Science.gov (United States)

    Verdoes, Martijn; Verhelst, Steven H L

    2016-01-01

    Proteases are involved in a wide variety of biologically and medically important events. They are entangled in a complex network of processes that regulate their activity, which makes their study intriguing, but challenging. For comprehensive understanding of protease biology and effective drug discovery, it is therefore essential to study proteases in models that are close to their complex native environments such as live cells or whole organisms. Protease activity can be detected by reporter substrates and activity-based probes, but not all of these reagents are suitable for intracellular or in vivo use. This review focuses on the detection of proteases in cells and in vivo. We summarize the use of probes and substrates as molecular tools, discuss strategies to deliver these tools inside cells, and describe sophisticated read-out techniques such as mass spectrometry and various imaging applications. This article is part of a Special Issue entitled: Physiological Enzymology and Protein Functions. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Plant proteases for bioactive peptides release: A review.

    Science.gov (United States)

    Mazorra-Manzano, M A; Ramírez-Suarez, J C; Yada, R Y

    2017-04-10

    Proteins are a potential source of health-promoting biomolecules with medical, nutraceutical, and food applications. Nowadays, bioactive peptides production, its isolation, characterization, and strategies for its delivery to target sites are a matter of intensive research. In vitro and in vivo studies regarding the bioactivity of peptides has generated strong evidence of their health benefits. Dairy proteins are considered the richest source of bioactive peptides, however proteins from animal and vegetable origin also have been shown to be important sources. Enzymatic hydrolysis has been the process most commonly used for bioactive peptide production. Most commercial enzymatic preparations frequently used are from animal (e.g., trypsin and pepsin) and microbial (e.g., Alcalase® and Neutrase®) sources. Although the use of plant proteases is still relatively limited to papain and bromelain from papaya and pineapple, respectively, the application of new plant proteases is increasing. This review presents the latest knowledge in the use and diversity of plant proteases for bioactive peptides release from food proteins including both available commercial plant proteases as well as new potential plant sources. Furthermore, the properties of peptides released by plant proteases and health benefits associated in the control of disorders such as hypertension, diabetes, obesity, and cancer are reviewed.

  15. Synthesis of glycinamides using protease immobilized magnetic nanoparticles

    Directory of Open Access Journals (Sweden)

    Abha Sahu

    2016-12-01

    Full Text Available In the present investigation, Bacillus subtilis was isolated from slaughterhouse waste and screened for the production of protease enzyme. The purified protease was successfully immobilized on magnetic nanoparticles (MNPs and used for the synthesis of series of glycinamides. The binding and thermal stability of protease on MNPs was confirmed by FTIR spectroscopy and TGA analysis. The surface morphology of MNPs before and after protease immobilization was carried out using SEM analysis. XRD pattern revealed no phase change in MNPs after enzyme immobilization. The processing parameters for glycinamides synthesis viz. temperature, pH, and time were optimized using Response Surface Methodology (RSM by using Design Expert (9.0.6.2. The maximum yield of various amides 2 butyramidoacetic acid (AMD-1,83.4%, 2-benzamidoacetic acid (AMD-2,80.5% and 2,2′((carboxymethyl amino-2-oxoethyl-2-hydroxysuccinylbis(azanediyldiacetic acid (AMD-3,80.8% formed was observed at pH-8, 50 °C and 30 min. The synthesized immobilized protease retained 70% of the initial activity even after 8 cycles of reuse.

  16. Evaluation of a D-amino-acid-containing fluorescence resonance energy transfer peptide library for profiling prokaryotic proteases

    NARCIS (Netherlands)

    Kaman, W.E.; Voskamp-Visser, I.; de Jongh, D.M.C.; Endtz, H.P.; van Belkum, A.; Hays, J.P.; Bikker, F.J.

    2013-01-01

    Bacterial proteases play an important role in a broad spectrum of processes, including colonization, proliferation, and virulence. In this respect, bacterial proteases are potential biomarkers for bacterial diagnosis and targets for novel therapeutic protease inhibitors. To investigate these

  17. The Cysteine Protease–Cysteine Protease Inhibitor System Explored in Soybean Nodule Development

    Directory of Open Access Journals (Sweden)

    Marian Dorcas Quain

    2013-08-01

    Full Text Available Almost all protease families have been associated with plant development, particularly senescence, which is the final developmental stage of every organ before cell death. Proteolysis remobilizes and recycles nitrogen from senescent organs that is required, for example, seed development. Senescence-associated expression of proteases has recently been characterized using large-scale gene expression analysis seeking to identify and characterize senescence-related genes. Increasing activities of proteolytic enzymes, particularly cysteine proteases, are observed during the senescence of legume nodules, in which a symbiotic relationship between the host plant and bacteria (Rhizobia facilitate the fixation of atmospheric nitrogen. It is generally considered that cysteine proteases are compartmentalized to prevent uncontrolled proteolysis in nitrogen-fixing nodules. In addition, the activities of cysteine proteases are regulated by endogenous cysteine protease inhibitors called cystatins. These small proteins form reversible complexes with cysteine proteases, leading to inactivation. However, very little is currently known about how the cysteine protease-cysteine protease inhibitor (cystatin system is regulated during nodule development. Moreover, our current understanding of the expression and functions of proteases and protease inhibitors in nodules is fragmented. To address this issue, we have summarized the current knowledge and techniques used for studying proteases and their inhibitors including the application of “omics” tools, with a particular focus on changes in the cysteine protease-cystatin system during nodule development.

  18. Characterization and identification of proteases secreted by Aspergillus fumigatus using free flow electrophoresis and MS.

    Science.gov (United States)

    Neustadt, Madlen; Costina, Victor; Kupfahl, Claudio; Buchheidt, Dieter; Eckerskorn, Christoph; Neumaier, Michael; Findeisen, Peter

    2009-06-01

    Early diagnosis of life-threatening invasive aspergillosis in neutropenic patients remains challenging because current laboratory methods have limited diagnostic sensitivity and/or specificity. Aspergillus species are known to secrete various pathogenetically relevant proteases and the monitoring of their protease activity in serum specimens might serve as a new diagnostic approach.For the characterization and identification of secreted proteases, the culture supernatant of Aspergillus fumigatus was fractionated using free flow electrophoresis (Becton Dickinson). Protease activity of separated fractions was measured using fluorescently labeled reporter peptides. Fractions were also co-incubated in parallel with various protease inhibitors that specifically inhibit a distinct class of proteases e.g. metallo- or cysteine-proteases. Those fractions with high protease activity were further subjected to LC-MS/MS analysis for protease identification. The highest protease activity was measured in fractions with an acidic pH range. The results of the 'inhibitor-panel' gave a clear indication that it is mainly metallo- and serine-proteases that are involved in the degradation of reporter peptides. Furthermore, several proteases were identified that facilitate the optimization of reporter peptides for functional protease profiling as a diagnostic tool for invasive aspergillosis.

  19. Middle East Respiratory Syndrome Coronavirus Nonstructural Protein 16 Is Necessary for Interferon Resistance and Viral Pathogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Menachery, Vineet D.; Gralinski, Lisa E.; Mitchell, Hugh D.; Dinnon, Kenneth H.; Leist, Sarah R.; Yount, Boyd L.; Graham, Rachel L.; McAnarney, Eileen T.; Stratton, Kelly G.; Cockrell, Adam S.; Debbink, Kari; Sims, Amy C.; Waters, Katrina M.; Baric, Ralph S.; Fernandez-Sesma, Ana

    2017-11-15

    ABSTRACT

    Coronaviruses (CoVs) encode a mixture of highly conserved and novel genes, as well as genetic elements necessary for infection and pathogenesis, raising the possibility of common targets for attenuation and therapeutic design. In this study, we focused on highly conserved nonstructural protein 16 (NSP16), a viral 2'O-methyltransferase (2'O-MTase) that encodes critical functions in immune modulation and infection. Using reverse genetics, we disrupted a key motif in the conserved KDKE motif of Middle East respiratory syndrome CoV (MERS-CoV) NSP16 (D130A) and evaluated the effect on viral infection and pathogenesis. While the absence of 2'O-MTase activity had only a marginal impact on propagation and replication in Vero cells, dNSP16 mutant MERS-CoV demonstrated significant attenuation relative to the control both in primary human airway cell cultures andin vivo. Further examination indicated that dNSP16 mutant MERS-CoV had a type I interferon (IFN)-based attenuation and was partially restored in the absence of molecules of IFN-induced proteins with tetratricopeptide repeats. Importantly, the robust attenuation permitted the use of dNSP16 mutant MERS-CoV as a live attenuated vaccine platform protecting from a challenge with a mouse-adapted MERS-CoV strain. These studies demonstrate the importance of the conserved 2'O-MTase activity for CoV pathogenesis and highlight NSP16 as a conserved universal target for rapid live attenuated vaccine design in an expanding CoV outbreak setting.

    IMPORTANCECoronavirus (CoV) emergence in both humans and livestock represents a significant threat to global public health, as evidenced by the sudden emergence of severe acute respiratory syndrome CoV (SARS-CoV), MERS-CoV, porcine epidemic diarrhea virus, and swine delta CoV in the 21st century. These studies describe an approach that

  20. Chemical Tools for the Study of Intramembrane Proteases.

    Science.gov (United States)

    Nguyen, Minh T N; Van Kersavond, Tim; Verhelst, Steven H L

    2015-11-20

    Intramembrane proteases (IMPs) reside inside lipid bilayers and perform peptide hydrolysis in transmembrane or juxtamembrane regions of their substrates. Many IMPs are involved in crucial regulatory pathways and human diseases, including Alzheimer's disease, Parkinson's disease, and diabetes. In the past, chemical tools have been instrumental in the study of soluble proteases, enabling biochemical and biomedical research in complex environments such as tissue lysates or living cells. However, IMPs place special challenges on probe design and applications, and progress has been much slower than for soluble proteases. In this review, we will give an overview of the available chemical tools for IMPs, including activity-based probes, affinity-based probes, and synthetic substrates. We will discuss how these have been used to increase our structural and functional understanding of this fascinating group of enzymes, and how they might be applied to address future questions and challenges.

  1. Effects of protease inhibitors on radiation transformation in vitro

    International Nuclear Information System (INIS)

    Kennedy, A.R.; Little, J.B.

    1981-01-01

    We have investigated the effects of three protease inhibitors, antipain, leupeptin, and soybean trypsin inhibitor, on the induction of oncogenic transformation in mouse C3H10T 1/2 cells by X-rays. The patterns of inhibition by the three protease inhibitors were different. Antipain was the most effective, having the ability to suppress completely radiation transformation as well as radiation transformation enhanced by the phorbol ester promoting agent 12-O-tetradecanoylphorbol-13-acetate. The fact that antipain could suppress transformation when present for only 1 day following irradiation suggests that an effect on a DNA repair process might be important in its action. Leupeptin was less effective than antipain in its inhibition of radiation transformation. Soybean trypsin inhibitor suppressed only the promotional effects of 12-O-tetradecanoylphorbol-13-acetate on transformation. Our results suggest that there may be more than one protease involved in carcinogenesis

  2. The binding mechanism of a peptidic cyclic serine protease inhibitor

    DEFF Research Database (Denmark)

    Jiang, Longguang; Svane, Anna Sigrid P.; Sørensen, Hans Peter

    2011-01-01

    Serine proteases are classical objects for studies of catalytic and inhibitory mechanisms as well as interesting as therapeutic targets. Since small-molecule serine protease inhibitors generally suffer from specificity problems, peptidic inhibitors, isolated from phage-displayed peptide libraries......, have attracted considerable attention. Here, we have investigated the mechanism of binding of peptidic inhibitors to serine protease targets. Our model is upain-1 (CSWRGLENHRMC), a disulfide-bond-constrained competitive inhibitor of human urokinase-type plasminogen activator with a noncanonical...... inhibitory mechanism and an unusually high specificity. Using a number of modified variants of upain-1, we characterised the upain-1-urokinase-type plasminogen activator complex using X-ray crystal structure analysis, determined a model of the peptide in solution by NMR spectroscopy, and analysed binding...

  3. The sialic acid binding activity of the S protein facilitates infection by porcine transmissible gastroenteritis coronavirus

    Directory of Open Access Journals (Sweden)

    Enjuanes Luis

    2011-09-01

    Full Text Available Abstract Background Transmissible gastroenteritis virus (TGEV has a sialic acid binding activity that is believed to be important for enteropathogenicity, but that has so far appeared to be dispensable for infection of cultured cells. The aims of this study were to determine the effect of sialic acid binding for the infection of cultured cells under unfavorable conditions, and comparison of TGEV strains and mutants, as well as the avian coronavirus IBV concerning their dependence on the sialic acid binding activity. Methods The infectivity of different viruses was analyzed by a plaque assay after adsorption times of 5, 20, and 60 min. Prior to infection, cultured cells were either treated with neuraminidase to deplete sialic acids from the cell surface, or mock-treated. In a second approach, pre-treatment of the virus with porcine intestinal mucin was performed, followed by the plaque assay after a 5 min adsorption time. A student's t-test was used to verify the significance of the results. Results Desialylation of cells only had a minor effect on the infection by TGEV strain Purdue 46 when an adsorption period of 60 min was allowed for initiation of infection. However, when the adsorption time was reduced to 5 min the infectivity on desialylated cells decreased by more than 60%. A TGEV PUR46 mutant (HAD3 deficient in sialic acid binding showed a 77% lower titer than the parental virus after a 5 min adsorption time. After an adsorption time of 60 min the titer of HAD3 was 58% lower than that of TGEV PUR46. Another TGEV strain, TGEV Miller, and IBV Beaudette showed a reduction in infectivity after neuraminidase treatment of the cultured cells irrespective of the virion adsorption time. Conclusions Our results suggest that the sialic acid binding activity facilitates the infection by TGEV under unfavorable environmental conditions. The dependence on the sialic acid binding activity for an efficient infection differs in the analyzed TGEV strains.

  4. Evidence supporting a zoonotic origin of human coronavirus strain NL63.

    Science.gov (United States)

    Huynh, Jeremy; Li, Shimena; Yount, Boyd; Smith, Alexander; Sturges, Leslie; Olsen, John C; Nagel, Juliet; Johnson, Joshua B; Agnihothram, Sudhakar; Gates, J Edward; Frieman, Matthew B; Baric, Ralph S; Donaldson, Eric F

    2012-12-01

    The relationship between bats and coronaviruses (CoVs) has received considerable attention since the severe acute respiratory syndrome (SARS)-like CoV was identified in the Chinese horseshoe bat (Rhinolophidae) in 2005. Since then, several bats throughout the world have been shown to shed CoV sequences, and presumably CoVs, in the feces; however, no bat CoVs have been isolated from nature. Moreover, there are very few bat cell lines or reagents available for investigating CoV replication in bat cells or for isolating bat CoVs adapted to specific bat species. Here, we show by molecular clock analysis that alphacoronavirus (α-CoV) sequences derived from the North American tricolored bat (Perimyotis subflavus) are predicted to share common ancestry with human CoV (HCoV)-NL63, with the most recent common ancestor between these viruses occurring approximately 563 to 822 years ago. Further, we developed immortalized bat cell lines from the lungs of this bat species to determine if these cells were capable of supporting infection with HCoVs. While SARS-CoV, mouse-adapted SARS-CoV (MA15), and chimeric SARS-CoVs bearing the spike genes of early human strains replicated inefficiently, HCoV-NL63 replicated for multiple passages in the immortalized lung cells from this bat species. These observations support the hypothesis that human CoVs are capable of establishing zoonotic-reverse zoonotic transmission cycles that may allow some CoVs to readily circulate and exchange genetic material between strains found in bats and other mammals, including humans.

  5. MERS coronaviruses from camels in Africa exhibit region-dependent genetic diversity.

    Science.gov (United States)

    Chu, Daniel K W; Hui, Kenrie P Y; Perera, Ranawaka A P M; Miguel, Eve; Niemeyer, Daniela; Zhao, Jincun; Channappanavar, Rudragouda; Dudas, Gytis; Oladipo, Jamiu O; Traoré, Amadou; Fassi-Fihri, Ouafaa; Ali, Abraham; Demissié, Getnet F; Muth, Doreen; Chan, Michael C W; Nicholls, John M; Meyerholz, David K; Kuranga, Sulyman A; Mamo, Gezahegne; Zhou, Ziqi; So, Ray T Y; Hemida, Maged G; Webby, Richard J; Roger, Francois; Rambaut, Andrew; Poon, Leo L M; Perlman, Stanley; Drosten, Christian; Chevalier, Veronique; Peiris, Malik

    2018-03-20

    Middle East respiratory syndrome coronavirus (MERS-CoV) causes a zoonotic respiratory disease of global public health concern, and dromedary camels are the only proven source of zoonotic infection. Although MERS-CoV infection is ubiquitous in dromedaries across Africa as well as in the Arabian Peninsula, zoonotic disease appears confined to the Arabian Peninsula. MERS-CoVs from Africa have hitherto been poorly studied. We genetically and phenotypically characterized MERS-CoV from dromedaries sampled in Morocco, Burkina Faso, Nigeria, and Ethiopia. Viruses from Africa (clade C) are phylogenetically distinct from contemporary viruses from the Arabian Peninsula (clades A and B) but remain antigenically similar in microneutralization tests. Viruses from West (Nigeria, Burkina Faso) and North (Morocco) Africa form a subclade, C1, that shares clade-defining genetic signatures including deletions in the accessory gene ORF4b Compared with human and camel MERS-CoV from Saudi Arabia, virus isolates from Burkina Faso (BF785) and Nigeria (Nig1657) had lower virus replication competence in Calu-3 cells and in ex vivo cultures of human bronchus and lung. BF785 replicated to lower titer in lungs of human DPP4-transduced mice. A reverse genetics-derived recombinant MERS-CoV (EMC) lacking ORF4b elicited higher type I and III IFN responses than the isogenic EMC virus in Calu-3 cells. However, ORF4b deletions may not be the major determinant of the reduced replication competence of BF785 and Nig1657. Genetic and phenotypic differences in West African viruses may be relevant to zoonotic potential. There is an urgent need for studies of MERS-CoV at the animal-human interface. Copyright © 2018 the Author(s). Published by PNAS.

  6. Laboratory investigation and phylogenetic analysis of an imported Middle East respiratory syndrome coronavirus case in Greece.

    Directory of Open Access Journals (Sweden)

    Athanasios Kossyvakis

    Full Text Available Rapid and reliable laboratory diagnosis of persons suspected of Middle East respiratory syndrome coronavirus (MERS-CoV infection is important for timely implementation of infection control practices and disease management. In addition, monitoring molecular changes in the virus can help elucidate chains of transmission and identify mutations that might influence virus transmission efficiency. This was illustrated by a recent laboratory investigation we conducted on an imported MERS-CoV case in Greece. Two oropharyngeal swab specimens were collected on the 1st and 2nd day of patient hospitalization and tested using two real-time RT-PCR (rRT-PCR assays targeting the UpE and Orf-1a regions of the MERS-CoV genome and RT-PCR and partial sequencing of RNA-dependent RNA polymerase and nucleocapsid genes. Serum specimens were also collected and serological test were performed. Results from the first swab sample were inconclusive while the second swab was strongly positive for MERS-CoV RNA by rRT-PCR and confirmed positive by RT-PCR and partial gene sequencing. Positive serologic test results further confirmed MERS-CoV infection. Full-length nucleocapsid and spike gene coding sequences were later obtained from the positive swab sample. Phylogenetic analysis revealed that the virus was closely related to recent human-derived MERS-CoV strains obtained in Jeddah and Makkah, Saudi Arabia, in April 2014 and dromedary camels in Saudi Arabia and Qatar. These findings were consistent with the patient's history. We also identified a unique amino acid substitution in the spike receptor binding domain that may have implications for receptor binding efficiency. Our initial inconclusive rRT-PCR results highlight the importance of collecting multiple specimens from suspect MERS-CoV cases and particularly specimens from the lower respiratory tract.

  7. Molecular dynamics of Middle East Respiratory Syndrome Coronavirus (MERS CoV) fusion heptad repeat trimers

    KAUST Repository

    Kandeel, Mahmoud

    2018-05-17

    Structural studies related to Middle East Respiratory Syndrome Coronavirus (MERS CoV) infection process are so limited. In this study, molecular dynamics (MD) simulation was carried out to unravel changes in the MERS CoV heptad repeat domains (HRs) and factors affecting fusion state HR stability. Results indicated that HR trimer is more rapidly stabilized, having stable system energy and lowest root mean square deviations (RMSDs). While trimers were the predominant active form of CoVs HR, monomers were also discovered in both of viral and cellular membranes. In order to find the differences between S2 monomer and trimer molecular dynamics, S2 monomer were modelled and subjected to MD simulation. In contrast to S2 trimer, S2 monomer was unstable, having high RMSDs with major drifts above 8 Å. Fluctuation of HR residue positions revealed major changes in the C-terminal of HR2 and the linker coil between HR1 and HR2 in both monomer and trimer. Hydrophobic residues at the “a” and “d” positions of HR helices stabilize the whole system, having minimal changes in RMSD. The global distance test and contact area difference scores support instability of MERS CoV S2 monomer. Analysis of HR1-HR2 inter-residue contacts and interaction energy revealed three different energy scales along HR helices. Two strong interaction energies were identified at the start of the HR2 helix and at the C-terminal of HR2. The identified critical residues by MD simulation and residues at a and d position of HR helix were strong stabilizers of HRs recognition.

  8. Ezrin interacts with the SARS coronavirus Spike protein and restrains infection at the entry stage.

    Directory of Open Access Journals (Sweden)

    Jean Kaoru Millet

    Full Text Available BACKGROUND: Entry of Severe Acute Respiratory Syndrome coronavirus (SARS-CoV and its envelope fusion with host cell membrane are controlled by a series of complex molecular mechanisms, largely dependent on the viral envelope glycoprotein Spike (S. There are still many unknowns on the implication of cellular factors that regulate the entry process. METHODOLOGY/PRINCIPAL FINDINGS: We performed a yeast two-hybrid screen using as bait the carboxy-terminal endodomain of S, which faces the cytosol during and after opening of the fusion pore at early stages of the virus life cycle. Here we show that the ezrin membrane-actin linker interacts with S endodomain through the F1 lobe of its FERM domain and that both the eight carboxy-terminal amino-acids and a membrane-proximal cysteine cluster of S endodomain are important for this interaction in vitro. Interestingly, we found that ezrin is present at the site of entry of S-pseudotyped lentiviral particles in Vero E6 cells. Targeting ezrin function by small interfering RNA increased S-mediated entry of pseudotyped particles in epithelial cells. Furthermore, deletion of the eight carboxy-terminal amino acids of S enhanced S-pseudotyped particles infection. Expression of the ezrin dominant negative FERM domain enhanced cell susceptibility to infection by SARS-CoV and S-pseudotyped particles and potentiated S-dependent membrane fusion. CONCLUSIONS/SIGNIFICANCE: Ezrin interacts with SARS-CoV S endodomain and limits virus entry and fusion. Our data present a novel mechanism involving a cellular factor in the regulation of S-dependent early events of infection.

  9. Retrospective testing and case series study of porcine delta coronavirus in U.S. swine herds.

    Science.gov (United States)

    McCluskey, Brian J; Haley, Charles; Rovira, Albert; Main, Rodger; Zhang, Yan; Barder, Sunny

    2016-01-01

    Porcine deltacoronavirus (PDCoV) was first reported in the United States (US) in February 2014. This was the second novel swine enteric coronavirus detected in the US since May 2013. In this study, we conducted retrospective testing of samples submitted to three veterinary diagnostic laboratories where qualifying biological samples were derived from previously submitted diagnostic case submissions from US commercial swine farms with a clinical history of enteric disease or from cases that had been previously tested for transmissible gastroenteritis virus, PEDV, or rotavirus. Overall, 2286 banked samples were tested from 27 States. Samples were collected in 3 separate years and in 17 different months. Test results revealed 4 positive samples, 3 collected in August 2013 and 1 collected in October 2013. In addition, a case series including 42 operations in 10 States was conducted through administration of a survey. Survey data collected included information on characteristics of swine operations that had experienced PDCoV clinical signs. Special emphasis was placed on obtaining descriptive estimates of biosecurity practices and disease status over time of each operation. Clinical signs of PDCoV were reported to be similar to those of PEDV. The average number of animals on each operation exhibiting clinical signs (morbidity) and the average number of case fatalities was greatest for suckling and weaned pigs. Average operation-level weaned pig morbidity was greatest in the first week of the outbreak while average operation-level suckling pig case fatality was greatest in the second week of the outbreak. The survey included questions regarding biosecurity practices for visitors and operation employees; trucks, equipment and drivers; and feed sources. These questions attempted to identify a likely pathway of introduction of PDCoV onto the operations surveyed. Published by Elsevier B.V.

  10. A mouse-adapted SARS-coronavirus causes disease and mortality in BALB/c mice.

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    Anjeanette Roberts

    2007-01-01

    Full Text Available No single animal model for severe acute respiratory syndrome (SARS reproduces all aspects of the human disease. Young inbred mice support SARS-coronavirus (SARS-CoV replication in the respiratory tract and are available in sufficient numbers for statistical evaluation. They are relatively inexpensive and easily accessible, but their use in SARS research is limited because they do not develop illness following infection. Older (12- to 14-mo-old BALB/c mice develop clinical illness and pneumonitis, but they can be hard to procure, and immune senescence complicates pathogenesis studies. We adapted the SARS-CoV (Urbani strain by serial passage in the respiratory tract of young BALB/c mice. Fifteen passages resulted in a virus (MA15 that is lethal for mice following intranasal inoculation. Lethality is preceded by rapid and high titer viral replication in lungs, viremia, and dissemination of virus to extrapulmonary sites accompanied by lymphopenia, neutrophilia, and pathological changes in the lungs. Abundant viral antigen is extensively distributed in bronchial epithelial cells and alveolar pneumocytes, and necrotic cellular debris is present in airways and alveoli, with only mild and focal pneumonitis. These observations suggest that mice infected with MA15 die from an overwhelming viral infection with extensive, virally mediated destruction of pneumocytes and ciliated epithelial cells. The MA15 virus has six coding mutations associated with adaptation and increased virulence; when introduced into a recombinant SARS-CoV, these mutations result in a highly virulent and lethal virus (rMA15, duplicating the phenotype of the biologically derived MA15 virus. Intranasal inoculation with MA15 reproduces many aspects of disease seen in severe human cases of SARS. The availability of the MA15 virus will enhance the use of the mouse model for SARS because infection with MA15 causes morbidity, mortality, and pulmonary pathology. This virus will be of value as

  11. Distinct patterns of IFITM-mediated restriction of filoviruses, SARS coronavirus, and influenza A virus.

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    I-Chueh Huang

    2011-01-01

    Full Text Available Interferon-inducible transmembrane proteins 1, 2, and 3 (IFITM1, 2, and 3 are recently identified viral restriction factors that inhibit infection mediated by the influenza A virus (IAV hemagglutinin (HA protein. Here we show that IFITM proteins restricted infection mediated by the entry glycoproteins (GP(1,2 of Marburg and Ebola filoviruses (MARV, EBOV. Consistent with these observations, interferon-β specifically restricted filovirus and IAV entry processes. IFITM proteins also inhibited replication of infectious MARV and EBOV. We observed distinct patterns of IFITM-mediated restriction: compared with IAV, the entry processes of MARV and EBOV were less restricted by IFITM3, but more restricted by IFITM1. Moreover, murine Ifitm5 and 6 did not restrict IAV, but efficiently inhibited filovirus entry. We further demonstrate that replication of infectious SARS coronavirus (SARS-CoV and entry mediated by the SARS-CoV spike (S protein are restricted by IFITM proteins. The profile of IFITM-mediated restriction of SARS-CoV was more similar to that of filoviruses than to IAV. Trypsin treatment of receptor-associated SARS-CoV pseudovirions, which bypasses their dependence on lysosomal cathepsin L, also bypassed IFITM-mediated restriction. However, IFITM proteins did not reduce cellular cathepsin activity or limit access of virions to acidic intracellular compartments. Our data indicate that IFITM-mediated restriction is localized to a late stage in the endocytic pathway. They further show that IFITM proteins differentially restrict the entry of a broad range of enveloped viruses, and modulate cellular tropism independently of viral receptor expression.

  12. Structural bases of coronavirus attachment to host aminopeptidase N and its inhibition by neutralizing antibodies.

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    Juan Reguera

    Full Text Available The coronaviruses (CoVs are enveloped viruses of animals and humans associated mostly with enteric and respiratory diseases, such as the severe acute respiratory syndrome and 10-20% of all common colds. A subset of CoVs uses the cell surface aminopeptidase N (APN, a membrane-bound metalloprotease, as a cell entry receptor. In these viruses, the envelope spike glycoprotein (S mediates the attachment of the virus particles to APN and subsequent cell entry, which can be blocked by neutralizing antibodies. Here we describe the crystal structures of the receptor-binding domains (RBDs of two closely related CoV strains, transmissible gastroenteritis virus (TGEV and porcine respiratory CoV (PRCV, in complex with their receptor, porcine APN (pAPN, or with a neutralizing antibody. The data provide detailed information on the architecture of the dimeric pAPN ectodomain and its interaction with the CoV S. We show that a protruding receptor-binding edge in the S determines virus-binding specificity for recessed glycan-containing surfaces in the membrane-distal region of the pAPN ectodomain. Comparison of the RBDs of TGEV and PRCV to those of other related CoVs, suggests that the conformation of the S receptor-binding region determines cell entry receptor specificity. Moreover, the receptor-binding edge is a major antigenic determinant in the TGEV envelope S that is targeted by neutralizing antibodies. Our results provide a compelling view on CoV cell entry and immune neutralization, and may aid the design of antivirals or CoV vaccines. APN is also considered a target for cancer therapy and its structure, reported here, could facilitate the development of anti-cancer drugs.

  13. Limitations of using feline coronavirus spike protein gene mutations to diagnose feline infectious peritonitis.

    Science.gov (United States)

    Barker, Emily N; Stranieri, Angelica; Helps, Chris R; Porter, Emily L; Davidson, Andrew D; Day, Michael J; Knowles, Toby; Kipar, Anja; Tasker, Séverine

    2017-10-05

    Feline infectious peritonitis (FIP) is a fatal disease of cats, and a sequela of systemic feline coronavirus (FCoV) infection. Mutations in the viral spike (S) gene have been associated with FCoVs found in tissues from cats with FIP, but not FCoVs found in faeces from healthy cats, and are implicated in monocyte/macrophage tropism and systemic spread. This study was designed to determine whether S gene mutation analysis can reliably diagnose FIP. Cats were categorised as with FIP (n = 57) or without FIP (n = 45) based on gross post-mortem and histopathological examination including immunohistochemistry for FCoV antigen. RNA was purified from available tissue, fluid and faeces. Reverse-transcriptase quantitative-PCR (RT-qPCR) was performed on all samples using FCoV-specific primers, followed by sequencing of a section of the S gene on RT-qPCR positive samples. Samples were available from a total of 102 cats. Tissue, fluid, and faecal samples from cats with FIP were more likely to be FCoV RT-qPCR-positive (90.4, 78.4 and 64.6% respectively) than those from cats without FIP (7.8, 2.1 and 20% respectively). Identification of S gene mutated FCoVs as an additional step to the detection of FCoV alone, only moderately increased specificity for tissue samples (from 92.6 to 94.6%) but specificity was unchanged for fluid samples (97.9%) for FIP diagnosis; however, sensitivity was markedly decreased for tissue (from 89.8 to 80.9%) and fluid samples (from 78.4 to 60%) for FIP diagnosis. These findings demonstrate that S gene mutation analysis in FCoVs does not substantially improve the ability to diagnose FIP as compared to detection of FCoV alone.

  14. Phylogenetic analysis of feline coronavirus strains in an epizootic outbreak of feline infectious peritonitis.

    Science.gov (United States)

    Barker, E N; Tasker, S; Gruffydd-Jones, T J; Tuplin, C K; Burton, K; Porter, E; Day, M J; Harley, R; Fews, D; Helps, C R; Siddell, S G

    2013-01-01

    Feline coronavirus (FCoV) infection is common. In a small percentage of cats, FCoV infection is associated with the fatal disease feline infectious peritonitis (FIP). Genetically distinct virulent and avirulent strains of FCoV might coexist within a cat population. To determine whether the strains of FCoV in FIP-affected cats are closely related or genetically distinct from the fecally derived strains of FCoV in contemporary-asymptomatic cats during an epizootic outbreak of FIP. Four cats euthanized because of FIP and 16 asymptomatic cats. This prospective outbreak investigation was initiated during an outbreak of FIP in cats within or rehomed from a rescue/rehoming center. Postmortem samples were collected from cats with FIP and contemporaneous fecal samples from asymptomatic cats. RNA was purified from tissue and fecal samples, FCoV gene fragments were reverse transcribed, PCR-amplified using novel primers, and sequenced. Sequences were aligned with ClustalW and compared with published FCoV sequences. FCoV RNA was detected in all 4 FIP cat postmortem samples and in 9 of the 16 fecal samples from contemporary-asymptomatic cats. Novel primers successfully amplified fragments from 4 regions of the genome for all FCoV-positive samples. Phylogenetic analysis showed that the FIP-associated strains of FCoV from the outbreak were very closely related to the fecally derived strains of FCoV from contemporary-asymptomatic cats. Sequence analysis provided no evidence that genetically distinct virulent and avirulent strains of FCoV were present during this FIP outbreak. Copyright © 2013 by the American College of Veterinary Internal Medicine.

  15. Proteome profile of swine testicular cells infected with porcine transmissible gastroenteritis coronavirus.

    Directory of Open Access Journals (Sweden)

    Ruili Ma

    Full Text Available The interactions occurring between a virus and a host cell during a viral infection are complex. The purpose of this paper was to analyze altered cellular protein levels in porcine transmissible gastroenteritis coronavirus (TGEV-infected swine testicular (ST cells in order to determine potential virus-host interactions. A proteomic approach using isobaric tags for relative and absolute quantitation (iTRAQ-coupled two-dimensional liquid chromatography-tandem mass spectrometry identification was conducted on the TGEV-infected ST cells. The results showed that the 4-plex iTRAQ-based quantitative approach identified 4,112 proteins, 146 of which showed significant changes in expression 48 h after infection. At 64 h post infection, 219 of these proteins showed significant change, further indicating that a larger number of proteomic changes appear to occur during the later stages of infection. Gene ontology analysis of the altered proteins showed enrichment in multiple biological processes, including cell adhesion, response to stress, generation of precursor metabolites and energy, cell motility, protein complex assembly, growth, developmental maturation, immune system process, extracellular matrix organization, locomotion, cell-cell signaling, neurological system process, and cell junction organization. Changes in the expression levels of transforming growth factor beta 1 (TGF-β1, caspase-8, and heat shock protein 90 alpha (HSP90α were also verified by western blot analysis. To our knowledge, this study is the first time the response profile of ST host cells following TGEV infection has been analyzed using iTRAQ technology, and our description of the late proteomic changes that are occurring after the time of vigorous viral production are novel. Therefore, this study provides a solid foundation for further investigation, and will likely help us to better understand the mechanisms of TGEV infection and pathogenesis.

  16. Mechanisms of Host Receptor Adaptation by Severe Acute Respiratory Syndrome Coronavirus

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Kailang; Peng, Guiqing; Wilken, Matthew; Geraghty, Robert J.; Li, Fang (UMMC)

    2012-12-10

    The severe acute respiratory syndrome coronavirus (SARS-CoV) from palm civets has twice evolved the capacity to infect humans by gaining binding affinity for human receptor angiotensin-converting enzyme 2 (ACE2). Numerous mutations have been identified in the receptor-binding domain (RBD) of different SARS-CoV strains isolated from humans or civets. Why these mutations were naturally selected or how SARS-CoV evolved to adapt to different host receptors has been poorly understood, presenting evolutionary and epidemic conundrums. In this study, we investigated the impact of these mutations on receptor recognition, an important determinant of SARS-CoV infection and pathogenesis. Using a combination of biochemical, functional, and crystallographic approaches, we elucidated the molecular and structural mechanisms of each of these naturally selected RBD mutations. These mutations either strengthen favorable interactions or reduce unfavorable interactions with two virus-binding hot spots on ACE2, and by doing so, they enhance viral interactions with either human (hACE2) or civet (cACE2) ACE2. Therefore, these mutations were viral adaptations to either hACE2 or cACE2. To corroborate the above analysis, we designed and characterized two optimized RBDs. The human-optimized RBD contains all of the hACE2-adapted residues (Phe-442, Phe-472, Asn-479, Asp-480, and Thr-487) and possesses exceptionally high affinity for hACE2 but relative low affinity for cACE2. The civet-optimized RBD contains all of the cACE2-adapted residues (Tyr-442, Pro-472, Arg-479, Gly-480, and Thr-487) and possesses exceptionally high affinity for cACE2 and also substantial affinity for hACE2. These results not only illustrate the detailed mechanisms of host receptor adaptation by SARS-CoV but also provide a molecular and structural basis for tracking future SARS-CoV evolution in animals.

  17. Analysis of intraviral protein-protein interactions of the SARS coronavirus ORFeome.

    Directory of Open Access Journals (Sweden)

    Albrecht von Brunn

    2007-05-01

    Full Text Available The severe acute respiratory syndrome coronavirus (SARS-CoV genome is predicted to encode 14 functional open reading frames, leading to the expression of up to 30 structural and non-structural protein products. The functions of a large number of viral ORFs are poorly understood or unknown. In order to gain more insight into functions and modes of action and interaction of the different proteins, we cloned the viral ORFeome and performed a genome-wide analysis for intraviral protein interactions and for intracellular localization. 900 pairwise interactions were tested by yeast-two-hybrid matrix analysis, and more than 65 positive non-redundant interactions, including six self interactions, were identified. About 38% of interactions were subsequently confirmed by CoIP in mammalian cells. Nsp2, nsp8 and ORF9b showed a wide range of interactions with other viral proteins. Nsp8 interacts with replicase proteins nsp2, nsp5, nsp6, nsp7, nsp8, nsp9, nsp12, nsp13 and nsp14, indicating a crucial role as a major player within the replication complex machinery. It was shown by others that nsp8 is essential for viral replication in vitro, whereas nsp2 is not. We show that also accessory protein ORF9b does not play a pivotal role for viral replication, as it can be deleted from the virus displaying normal plaque sizes and growth characteristics in Vero cells. However, it can be expected to be important for the virus-host interplay and for pathogenicity, due to its large number of interactions, by enhancing the global stability of the SARS proteome network, or play some unrealized role in regulating protein-protein interactions. The interactions identified provide valuable material for future studies.

  18. Significance of Coronavirus Mutants in Feces and Diseased Tissues of Cats Suffering from Feline Infectious Peritonitis

    Directory of Open Access Journals (Sweden)

    Niels C. Pedersen

    2009-08-01

    Full Text Available The internal FECV→FIPV mutation theory and three of its correlates were tested in four sibs/half-sib kittens, a healthy contact cat, and in four unrelated cats that died of FIP at geographically disparate regions. Coronavirus from feces and extraintestinal FIP lesions from the same cat were always >99% related in accessory and structural gene sequences. SNPs and deletions causing a truncation of the 3c gene product were found in almost all isolates from the diseased tissues of the eight cats suffering from FIP, whereas most, but not all fecal isolates from these same cats had intact 3c genes. Other accessory and structural genes appeared normal in both fecal and lesional viruses. Deliterious mutations in the 3c gene were unique to each cat, indicating that they did not originate in one cat and were subsequently passed horizontally to the others. Compartmentalization of the parental and mutant forms was not absolute; virus of lesional type was sometimes found in feces of affected cats and virus identical to fecal type was occasionally identified in diseased tissues. Although 3c gene mutants in this study were not horizontally transmitted, the parental fecal virus was readily transmitted by contact from a cat that died of FIP to its housemate. There was a high rate of mutability in all structural and accessory genes both within and between cats, leading to minor genetic variants. More than one variant could be identified in both diseased tissues and feces of the same cat. Laboratory cats inoculated with a mixture of two closely related variants from the same FIP cat developed disease from one or the other variant, but not both. Significant genetic drift existed between isolates from geographically distinct regions of the Western US.

  19. Significance of coronavirus mutants in feces and diseased tissues of cats suffering from feline infectious peritonitis.

    Science.gov (United States)

    Pedersen, Niels C; Liu, Hongwei; Dodd, Kimberly A; Pesavento, Patricia A

    2009-09-01

    The internal FECV→FIPV mutation theory and three of its correlates were tested in four sibs/half-sib kittens, a healthy contact cat, and in four unrelated cats that died of FIP at geographically disparate regions. Coronavirus from feces and extraintestinal FIP lesions from the same cat were always >99% related in accessory and structural gene sequences. SNPs and deletions causing a truncation of the 3c gene product were found in almost all isolates from the diseased tissues of the eight cats suffering from FIP, whereas most, but not all fecal isolates from these same cats had intact 3c genes. Other accessory and structural genes appeared normal in both fecal and lesional viruses. Deliterious mutations in the 3c gene were unique to each cat, indicating that they did not originate in one cat and were subsequently passed horizontally to the others. Compartmentalization of the parental and mutant forms was not absolute; virus of lesional type was sometimes found in feces of affected cats and virus identical to fecal type was occasionally identified in diseased tissues. Although 3c gene mutants in this study were not horizontally transmitted, the parental fecal virus was readily transmitted by contact from a cat that died of FIP to its housemate. There was a high rate of mutability in all structural and accessory genes both within and between cats, leading to minor genetic variants. More than one variant could be identified in both diseased tissues and feces of the same cat. Laboratory cats inoculated with a mixture of two closely related variants from the same FIP cat developed disease from one or the other variant, but not both. Significant genetic drift existed between isolates from geographically distinct regions of the Western US.

  20. Molecular and phylogenetic characterization of bovine coronavirus virus isolated from dairy cattle in Central Region, Thailand.

    Science.gov (United States)

    Singasa, Kanokwan; Songserm, Taweesak; Lertwatcharasarakul, Preeda; Arunvipas, Pipat

    2017-10-01

    Bovine coronavirus (BCoV) is involved mainly in enteric infections in cattle. This study reports the first molecular detection of BCoV in a diarrhea outbreak in dairy cows in the Central Region, Thailand. BCoV was molecularly detected from bloody diarrheic cattle feces by using nested PCR. Agarose gel electrophoresis of three diarrheic fecal samples yielded from the 25 samples desired amplicons that were 488 base pairs and sequencing substantiated that have BCoV. The sequence alignment indicated that nucleotide and amino acid sequences, the three TWD isolated in Thailand, were more quite homologous to each other (amino acid at position 39 of TWD1, TWD3 was proline, but TWD2 was serine) and closely related to OK-0514-3strain (virulent respiratory strain; RBCoV).The amino acid sequencing identities among TWD1, TWD2,TWD3, and OK-0514-3 strain were 96.0 to 96.6%, those at which T3I, H65N, D87G, H127Y, andQ136R were changed. In addition, the phylogenetic tree of the hypervariable region S1subunit spike glycoprotein BCoV gene was composed of three major clades by using the 54 sequences generated and showed that the evolutionally distance, TWD1, TWD2, and TWD3 were the isolated group together and most similar to OK-0514-3 strain (98.2 to 98.5% similarity). Further study will develop ELISA assay for serologic detection of winter dysentery disease.

  1. Purification and characterization of alkaline proteases from aspergillus terreus

    International Nuclear Information System (INIS)

    Hussain, A.; Mannan, A.; Zubair, H.; Mirza, B.

    2010-01-01

    Proteases belong to an important class of enzymes known as hydrolases and catalyze hydrolysis of proteins. They act primarily to degrade proteins that are used for energy production and as biosynthetic precursors. In the following study, protease produced from Aspergillus terreus was found to be thermo stable and included in the category of alkaline serine and metallo protease. During partial purification, presence of enzyme in 60% (NH/sub 4/)/sub 2/SO/sub 4/ indicated small molecular weight polypeptide; later purification with Sephadex G-75 fractionation yielded a single proteolytic active molecule. At final purification step, the increase in specific activity of the enzyme was 7.5 fold with 23% yield. SDS-PAGE analysis revealed that alkaline protease of Aspergillus terreus is a monomer with approximate molecular weight of 35 kDa. Optimum pH for protease activity was found in the range of 7.5-11.0 (maximum at pH 8.5), thus apparently classified as an alkaline protease. The enzyme was thermo stable towards high temperature (60 deg. C), however it denatured irreversibly at 70 deg. C showing 80% loss of activity. The maximum proteolytic activity was found at 40 deg. C. The enzyme was effectively inhibited by PMSF, EDTA and urea whereas iodoacetamide and thiourea did not result in any loss in activity while cysteine was found to be activator molecule. The study with metal ions Mg/sup +2/, Mn/sup +2/ and Fe/sup +3/ (1 mM each) showed minute stimulatory effects on enzyme activity. Co/sup +2/ and Ca/sup +2/ (1 mM) had neither excitatory nor inhibitory effect while Hg/sup +2/ and Cu/sup +2/ (1 mM) slightly reduced the enzyme activity. (author)

  2. m-AAA proteases, mitochondrial calcium homeostasis and neurodegeneration.

    Science.gov (United States)

    Patron, Maria; Sprenger, Hans-Georg; Langer, Thomas

    2018-03-01

    The function of mitochondria depends on ubiquitously expressed and evolutionary conserved m-AAA proteases in the inner membrane. These ATP-dependent peptidases form hexameric complexes built up of homologous subunits. AFG3L2 subunits assemble either into homo-oligomeric isoenzymes or with SPG7 (paraplegin) subunits into hetero-oligomeric proteolytic complexes. Mutations in AFG3L2 are associated with dominant spinocerebellar ataxia (SCA28) characterized by the loss of Purkinje cells, whereas mutations in SPG7 cause a recessive form of hereditary spastic paraplegia (HSP7) with motor neurons of the cortico-spinal tract being predominantly affected. Pleiotropic functions have been assigned to m-AAA proteases, which act as quality control and regulatory enzymes in mitochondria. Loss of m-AAA proteases affects mitochondrial protein synthesis and respiration and leads to mitochondrial fragmentation and deficiencies in the axonal transport of mitochondria. Moreover m-AAA proteases regulate the assembly of the mitochondrial calcium uniporter (MCU) complex. Impaired degradation of the MCU subunit EMRE in AFG3L2-deficient mitochondria results in the formation of deregulated MCU complexes, increased mitochondrial calcium uptake and increased vulnerability of neurons for calcium-induced cell death. A reduction of calcium influx into the cytosol of Purkinje cells rescues ataxia in an AFG3L2-deficient mouse model. In this review, we discuss the relationship between the m-AAA protease and mitochondrial calcium homeostasis and its relevance for neurodegeneration and describe a novel mouse model lacking MCU specifically in Purkinje cells. Our results pledge for a novel view on m-AAA proteases that integrates their pleiotropic functions in mitochondria to explain the pathogenesis of associated neurodegenerative disorders.

  3. Human eosinophils constitutively express a unique serine protease, PRSS33.

    Science.gov (United States)

    Toyama, Sumika; Okada, Naoko; Matsuda, Akio; Morita, Hideaki; Saito, Hirohisa; Fujisawa, Takao; Nakae, Susumu; Karasuyama, Hajime; Matsumoto, Kenji

    2017-07-01

    Eosinophils play important roles in asthma, especially airway remodeling, by producing various granule proteins, chemical mediators, cytokines, chemokines and proteases. However, protease production by eosinophils is not fully understood. In the present study, we investigated the production of eosinophil-specific proteases/proteinases by transcriptome analysis. Human eosinophils and other cells were purified from peripheral blood by density gradient sedimentation and negative/positive selections using immunomagnetic beads. Protease/proteinase expression in eosinophils and release into the supernatant were evaluated by microarray analysis, qPCR, ELISA, flow cytometry and immunofluorescence staining before and after stimulation with eosinophil-activating cytokines and secretagogues. mRNAs for extracellular matrix proteins in human normal fibroblasts were measured by qPCR after exposure to recombinant protease serine 33 (PRSS33) protein (rPRSS33), created with a baculovirus system. Human eosinophils expressed relatively high levels of mRNA for metalloproteinase 25 (MMP25), a disintegrin and metalloprotease 8 (ADAM8), ADAM10, ADAM19 and PRSS33. Expression of PRSS33 was the highest and eosinophil-specific. PRSS33 mRNA expression was not affected by eosinophil-activating cytokines. Immunofluorescence staining showed that PRSS33 was co-localized with an eosinophil granule protein. PRSS33 was not detected in the culture supernatant of eosinophils even after stimulation with secretagogues, but its cell surface expression was increased. rPRSS33 stimulation of human fibroblasts increased expression of collagen and fibronectin mRNAs, at least in part via protease-activated receptor-2 activation. Activated eosinophils may induce fibroblast extracellular matrix protein synthesis via cell surface expression of PRSS33, which would at least partly explain eosinophils' role(s) in airway remodeling. Copyright © 2017 Japanese Society of Allergology. Production and hosting by Elsevier

  4. The use of enzyme-linked immunosorbent assay systems for the serology and antigen detection in parvovirus, coronavirus and rotavirus infections in dogs in The Netherlands.

    NARCIS (Netherlands)

    G.F. Rimmelzwaan (Guus); J. Groen (Jan); H.F. Egberink (Herman); G.H.A. Borst (Gerrit); F.G.C.M. Uytdehaag (Fons); A.D.M.E. Osterhaus (Albert)

    1991-01-01

    textabstractComplex trapping blocking (CTB) enzyme-linked immunosorbent assays (ELISAs) and indirect ELISAs for the detection of antibodies to canine parvovirus (CPV), canine coronavirus (CCV) and rotavirus in sera of dogs were established. Double antibody sandwich ELISAs for the detection of CPV-,

  5. Middle East respiratory syndrome coronavirus (MERS-CoV) RNA and neutralising antibodies in milk collected according to local customs from dromedary camels, Qatar, April 2014

    NARCIS (Netherlands)

    Reusken, C B; Farag, E A; Jonges, M; Godeke, G J; El-Sayed, A M; Pas, S D; Raj, V S; Mohran, K A; Moussa, H A; Ghobashy, H; Alhajri, F; Ibrahim, A K; Bosch, B J; Pasha, S K; Al-Romaihi, H E; Al-Thani, M; Al-Marri, S A; AlHajri, M M; Haagmans, B L; Koopmans, M P

    2014-01-01

    Antibodies to Middle East respiratory syndrome coronavirus (MERS-CoV) were detected in serum and milk collected according to local customs from 33 camels in Qatar, April 2014. At one location, evidence for active virus shedding in nasal secretions and/or faeces was observed for 7/12 camels; viral

  6. The coronavirus transmissible gastroenteritis virus causes infection after receptor-mediated endocytosis and acid-dependent fusion with an intracellular compartment

    DEFF Research Database (Denmark)

    Hansen, Gert Helge; Delmas, B; Besnardeau, L

    1998-01-01

    Aminopeptidase N is a species-specific receptor for transmissible gastroenteritis virus (TGEV), which infects piglets, and for the 229E virus, which infects humans. It is not known whether these coronaviruses are endocytosed before fusion with a membrane of the target cell, causing a productive...

  7. The sample of choice for detecting Middle East respiratory syndrome coronavirus in asymptomatic dromedary camels using real-time reversetranscription polymerase chain reaction.

    NARCIS (Netherlands)

    Mohran, K A; Farag, E A B; Reusken, C B E; Raj, V S; Lamers, M M; Pas, S D; Voermans, J; Smits, S L; Alhajri, M M; Alhajri, F; Al-Romaihi, H E; Ghobashy, H; El-Maghraby, M M; Al Dhahiry, S H S; Al-Mawlawi, N; El-Sayed, A M; Al-Thani, M; Al-Marri, S A; Haagmans, B L; Koopmans, M P G

    2016-01-01

    The newly identified Middle East respiratory syndrome coronavirus (MERS-CoV), which causes severe respiratory disease, particularly in people with comorbidities, requires further investigation. Studies in Qatar and elsewhere have provided evidence that dromedary camels are a reservoir for the virus,

  8. Structure of a SARS coronavirus-derived peptide bound to the human major histocompatibility complex class I molecule HLA-B*1501

    DEFF Research Database (Denmark)

    Røder, Gustav; Kristensen, Ole; Kastrup, Jette S

    2008-01-01

    , the crystal structure of HLA-B*1501 in complex with a SARS coronavirus-derived nonapeptide (VQQESSFVM) has been determined at high resolution (1.87 A). The peptide is deeply anchored in the B and F pockets, but with the Glu4 residue pointing away from the floor in the peptide-binding groove, making...

  9. A novel pancoronavirus RT-PCR assay: frequent detection of human coronavirus NL63 in children hospitalized with respiratory tract infections in Belgium

    Directory of Open Access Journals (Sweden)

    Berkhout Ben

    2005-02-01

    Full Text Available Abstract Background Four human coronaviruses are currently known to infect the respiratory tract: human coronaviruses OC43 (HCoV-OC43 and 229E (HCoV-229E, SARS associated coronavirus (SARS-CoV and the recently identified human coronavirus NL63 (HCoV-NL63. In this study we explored the incidence of HCoV-NL63 infection in children diagnosed with respiratory tract infections in Belgium. Methods Samples from children hospitalized with respiratory diseases during the winter seasons of 2003 and 2004 were evaluated for the presence of HCoV-NL63 using a optimized pancoronavirus RT-PCR assay. Results Seven HCoV-NL63 positive samples were identified, six were collected during January/February 2003 and one at the end of February 2004. Conclusions Our results support the notation that HCoV-NL63 can cause serious respiratory symptoms in children. Sequence analysis of the S gene showed that our isolates could be classified into two subtypes corresponding to the two prototype HCoV-NL63 sequences isolated in The Netherlands in 1988 and 2003, indicating that these two subtypes may currently be cocirculating.

  10. Construction of recombinant Newcastle disease virus expressing the S1 protein of Turkey enteric coronavirus for use as a bivalent vaccine

    Science.gov (United States)

    Turkey enteric coronavirus (TCoV) causes a contagious form of enteritis in turkeys, generally recognized in the field by outward signs including diarrhea and decreased weight gain, resulting in severe economic losses for the poultry industry in the US. To date there is no commercial vaccine availab...

  11. Chemistry and biology of natural product derived protease inhibitors

    OpenAIRE

    Stolze, Sara Christina

    2012-01-01

    Im Rahmen dieser Dissertation sollten Naturstoffe und davon abgeleitete Derivate synthetisiert und im Hinblick auf ihre biologische Aktivität als Protease-Inhibitoren untersucht werden. Für die Naturstoffklasse der 3-Amino-6-Hydroxy-2-piperidon(Ahp)-Cyclodepsipeptide, die als nicht-kovalente Serin-Protease-Inhibitoren bekannt sind, konnte eine Festphasensynthese basierend auf einem allgemeinen Ahp-Vorläufermolekül entwickelt werden. Für den Ahp-Vorläufer wurde eine Lösungssynthese entwicke...

  12. Feline infectious peritonitis: insights into feline coronavirus pathobiogenesis and epidemiology based on genetic analysis of the viral 3c gene.

    Science.gov (United States)

    Chang, Hui-Wen; de Groot, Raoul J; Egberink, Herman F; Rottier, Peter J M

    2010-02-01

    Feline infectious peritonitis (FIP) is a lethal systemic disease caused by FIP virus (FIPV), a virulent mutant of apathogenic feline enteric coronavirus (FECV). We analysed the 3c gene--a proposed virulence marker--in 27 FECV- and 28 FIPV-infected cats. Our findings suggest that functional 3c protein expression is crucial for FECV replication in the gut, but dispensable for systemic FIPV replication. Whilst intact in all FECVs, the 3c gene was mutated in the majority (71.4 %) of FIPVs, but not in all, implying that mutation in 3c is not the (single) cause of FIP. Most cats with FIP had no detectable intestinal feline coronaviruses (FCoVs) and had seemingly cleared the primary FECV infection. In those with detectable intestinal FCoV, the virus always had an intact 3c and seemed to have been acquired by FECV superinfection. Apparently, 3c-inactivated viruses replicate not at all--or only poorly--in the gut, explaining the rare incidence of FIP outbreaks.

  13. Comparative in vivo analysis of recombinant type II feline coronaviruses with truncated and completed ORF3 region.

    Directory of Open Access Journals (Sweden)

    Ádám Bálint

    Full Text Available Our previous in vitro comparative study on a feline coronavirus (FCoV pair, differing only in the intactness of their ORF3abc regions, showed that the truncated ORF3abc plays an important role in the efficient macrophage/monocyte tropism of type II feline infectious peritonitis virus (FIPV. In the present study, we describe a challenge experiment with the same recombinant FCoVs in order to gain data on the in vivo characteristics on these viruses. While parent virus FIPV DF-2 developed feline infectious peritonitis in all the infected cats, its recombinant virus PBFIPV-DF-2, differing only in seven nucleotides, proved to be surprisingly low virulent, although caused an acute febrile episode similarly to the original FIPV DF-2. PBFIPV-DF-2 infection induced significantly lower virus neutralization titers than its parent virus, and lacked the second phase of viremia and development of fatal course of the disease. The recombinant PBFIPV-DF-2-R3i with completed ORF3abc gained biological properties that differentiate between the feline enteric coronavirus (FECV and FIPV biotypes such as intensive replication in the gut, absence of viremia and weak or no serological response. Using reverse genetic approaches our study is the first experimental proof that ORF3abc is indeed responsible for the restriction of FECV replication to the intestine in vivo.

  14. Comparative In Vivo Analysis of Recombinant Type II Feline Coronaviruses with Truncated and Completed ORF3 Region

    Science.gov (United States)

    Bálint, Ádám; Farsang, Attila; Zádori, Zoltán; Belák, Sándor

    2014-01-01

    Our previous in vitro comparative study on a feline coronavirus (FCoV) pair, differing only in the intactness of their ORF3abc regions, showed that the truncated ORF3abc plays an important role in the efficient macrophage/monocyte tropism of type II feline infectious peritonitis virus (FIPV). In the present study, we describe a challenge experiment with the same recombinant FCoVs in order to gain data on the in vivo characteristics on these viruses. While parent virus FIPV DF-2 developed feline infectious peritonitis in all the infected cats, its recombinant virus PBFIPV-DF-2, differing only in seven nucleotides, proved to be surprisingly low virulent, although caused an acute febrile episode similarly to the original FIPV DF-2. PBFIPV-DF-2 infection induced significantly lower virus neutralization titers than its parent virus, and lacked the second phase of viremia and development of fatal course of the disease. The recombinant PBFIPV-DF-2-R3i with completed ORF3abc gained biological properties that differentiate between the feline enteric coronavirus (FECV) and FIPV biotypes such as intensive replication in the gut, absence of viremia and weak or no serological response. Using reverse genetic approaches our study is the first experimental proof that ORF3abc is indeed responsible for the restriction of FECV replication to the intestine in vivo. PMID:24586385

  15. Boosted protease inhibitors and the electrocardiographic measures of QT and PR durations

    DEFF Research Database (Denmark)

    Soliman, Elsayed Z; Lundgren, Jens D; Roediger, Mollie P

    2011-01-01

    There are contradictory reports regarding the effects of protease inhibitors on the ECG measures of QT and PR interval durations. The effect of interrupting use of protease inhibitors on QT and PR progression is also unknown.......There are contradictory reports regarding the effects of protease inhibitors on the ECG measures of QT and PR interval durations. The effect of interrupting use of protease inhibitors on QT and PR progression is also unknown....

  16. Semi-continuous in situ magnetic separation for enhanced extracellular protease productionmodeling and experimental validation

    DEFF Research Database (Denmark)

    Cerff, M.; Scholz, A.; Käppler, T.

    2013-01-01

    In modern biotechnology proteases play a major role as detergent ingredients. Especially the production of extracellular protease by Bacillus species facilitates downstream processing because the protease can be directly harvested from the biosuspension. In situ magnetic separation (ISMS...... production, and was used to optimize ISMS steps to obtain the maximum overall protease yield. Biotechnol. Bioeng. 2013; 110: 2161–2172. © 2013 Wiley Periodicals, Inc....

  17. Effects of eye rubbing on the levels of protease, protease activity and cytokines in tears: relevance in keratoconus.

    Science.gov (United States)

    Balasubramanian, Sivaraman A; Pye, David C; Willcox, Mark D P

    2013-03-01

    Proteases, protease activity and inflammatory molecules in tears have been found to be relevant in the pathogenesis of keratoconus. We sought to determine the influence of eye rubbing on protease expression, protease activity and concentration of inflammatory molecules in tears. Basal tears were collected from normal volunteers before and after 60 seconds of experimental eye rubbing. The total amount of matrix metalloproteinase (MMP)-13 and inflammatory molecules interleukin (IL)-6 and tumour necrosis factor (TNF)-α in the tear samples were measured using specific enzyme-linked immunosorbent assays (ELISA). Tear collagenase activity was investigated using a specific activity assay. The concentrations of MMP-13 (51.9 ± 34.3 versus 63 ± 36.8 pg/ml, p = 0.006), IL-6 (1.24 ± 0.98 versus 2.02 ± 1.52 pg/ml, p = 0.004) and TNF-α (1.16 ± 0.74 versus 1.44 ± 0.66 pg/ml, p = 0.003) were significantly increased in normal subjects after eye rubbing. The experimental eye rub did not alter significantly the collagenase activity (5.02 ± 3 versus 7.50 ± 3.90 fluorescent intensity units, p = 0.14) of tears. Eye rubbing for 60 seconds increased the level of tear MMP-13, IL-6 and TNF-α in normal study subjects. This increase in protease, protease activity and inflammatory mediators in tears after eye rubbing may be exacerbated even further during persistent and forceful eye rubbing seen in people with keratoconus and this in turn may contribute to the progression of the disease. © 2013 The Authors. Clinical and Experimental Optometry © 2013 Optometrists Association Australia.

  18. Detection of potentially novel paramyxovirus and coronavirus viral RNA in bats and rats in the Mekong Delta region of southern Viet Nam.

    Science.gov (United States)

    Berto, A; Anh, P H; Carrique-Mas, J J; Simmonds, P; Van Cuong, N; Tue, N T; Van Dung, N; Woolhouse, M E; Smith, I; Marsh, G A; Bryant, J E; Thwaites, G E; Baker, S; Rabaa, M A

    2018-02-01

    Bats and rodents are being increasingly recognized as reservoirs of emerging zoonotic viruses. Various studies have investigated bat viruses in tropical regions, but to date there are no data regarding viruses with zoonotic potential that circulate in bat and rat populations in Viet Nam. To address this paucity of data, we sampled three bat farms and three wet markets trading in rat meat in the Mekong Delta region of southern Viet Nam. Faecal and urine samples were screened for the presence of RNA from paramyxoviruses, coronaviruses and filoviruses. Paramyxovirus RNA was detected in 4 of 248 (1%) and 11 of 222 (4.9%) bat faecal and urine samples, respectively. Coronavirus RNA was detected in 55 of 248 (22%) of bat faecal samples; filovirus RNA was not detected in any of the bat samples. Further, coronavirus RNA was detected in 12 of 270 (4.4%) of rat faecal samples; all samples tested negative for paramyxovirus. Phylogenetic analysis revealed that the bat paramyxoviruses and bat and rat coronaviruses were related to viruses circulating in bat and rodent populations globally, but showed no cross-species mixing of viruses between bat and rat populations within Viet Nam. Our study shows that potentially novel variants of paramyxoviruses and coronaviruses commonly circulate in bat and rat populations in Viet Nam. Further characterization of the viruses and additional human and animal surveillance is required to evaluate the likelihood of viral spillover and to assess whether these viruses pose a risk to human health. © 2017 The Authors. Zoonoses and Public Health Published by Blackwell Verlag GmbH.

  19. Characterization of the Aspergillus niger prtT, a unique regulator of extracellular protease encoding genes

    NARCIS (Netherlands)

    Punt, P.J.; Schuren, F.H.J.; Lehmbeck, J.; Christensen, T.; Hjort, C.; Hondel, C.A.M.J.J. van den

    2008-01-01

    Expression of several Aspergillus niger genes encoding major secreted, but not vacuolar, protease genes including the major acid protease gene pepA, was shown to be affected in the previously isolated A. niger protease mutant, AB1.13 [Mattern, I.E., van Noort, J.M., van den Berg, P., Archer, D.A.,

  20. Higher Desolvation Energy Reduces Molecular Recognition in Multi-Drug Resistant HIV-1 Protease

    Directory of Open Access Journals (Sweden)

    Ladislau C. Kovari

    2012-05-01

    Full Text Available Designing HIV-1 protease inhibitors that overcome drug-resistance is still a challenging task. In this study, four clinical isolates of multi-drug resistant HIV-1 proteases that exhibit resistance to all the US FDA-approved HIV-1 protease inhibitors and also reduce the substrate recognition ability were examined. A multi-drug resistant HIV-1 protease isolate, MDR 769, was co-crystallized with the p2/NC substrate and the mutated CA/p2 substrate, CA/p2 P1’F. Both substrates display different levels of molecular recognition by the wild-type and multi-drug resistant HIV-1 protease. From the crystal structures, only limited differences can be identified between the wild-type and multi-drug resistant protease. Therefore, a wild-type HIV-1 protease and four multi-drug resistant HIV-1 proteases in complex with the two peptides were modeled based on the crystal structures and examined during a 10 ns-molecular dynamics simulation. The simulation results reveal that the multi-drug resistant HIV-1 proteases require higher desolvation energy to form complexes with the peptides. This result suggests that the desolvation of the HIV-1 protease active site is an important step of protease-ligand complex formation as well as drug resistance. Therefore, desolvation energy could be considered as a parameter in the evaluation of future HIV-1 protease inhibitor candidates.

  1. Teaching Foundational Topics and Scientific Skills in Biochemistry within the Conceptual Framework of HIV Protease

    Science.gov (United States)

    Johnson, R. Jeremy

    2014-01-01

    HIV protease has served as a model protein for understanding protein structure, enzyme kinetics, structure-based drug design, and protein evolution. Inhibitors of HIV protease are also an essential part of effective HIV/AIDS treatment and have provided great societal benefits. The broad applications for HIV protease and its inhibitors make it a…

  2. 21 CFR 184.1027 - Mixed carbohydrase and protease enzyme product.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Mixed carbohydrase and protease enzyme product. 184... RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1027 Mixed carbohydrase and protease enzyme product. (a) Mixed carbohydrase and protease enzyme product is an enzyme preparation that includes...

  3. Identification and isoforms specificity of barley (Hordeum vulgare) grain proteinaceous inhibitors of commercial feed protease

    DEFF Research Database (Denmark)

    Dionisio, Giuseppe; Brinch-Pedersen, Henrik

    2016-01-01

    Protease is commonly used as feed additive. Ronozyme® ProAct, a subtilisin-like serine feed protease is different from the already characterized Bacillus subtilisin-like serine protease. When used in wheat and barley based feed, its degree of efficiency differs according to the cultivar in analys...

  4. A Kunitz-type cysteine protease inhibitor from cauliflower and Arabidopsis

    DEFF Research Database (Denmark)

    Halls, C.E.; Rogers, S. W.; Ouffattole, M.

    2006-01-01

    proaleurain maturation protease and of papain when assayed at pH 4.5 but not at pH 6.3. In a pull-down assay, the inhibitor bound tightly to papain, but only weakly to the aspartate protease pepsin. When the cauliflower protease inhibitor was transiently expressed in tobacco suspension culture protoplasts...

  5. Molecular Basis for Drug Resistance in HIV-1 Protease

    Directory of Open Access Journals (Sweden)

    Celia A. Schiffer

    2010-11-01

    Full Text Available HIV-1 protease is one of the major antiviral targets in the treatment of patients infected with HIV-1. The nine FDA approved HIV-1 protease inhibitors were developed with extensive use of structure-based drug design, thus the atomic details of how the inhibitors bind are well characterized. From this structural understanding the molecular basis for drug resistance in HIV-1 protease can be elucidated. Selected mutations in response to therapy and diversity between clades in HIV-1 protease have altered the shape of the active site, potentially altered the dynamics and even altered the sequence of the cleavage sites in the Gag polyprotein. All of these interdependent changes act in synergy to confer drug resistance while simultaneously maintaining the fitness of the virus. New strategies, such as incorporation of the substrate envelope constraint to design robust inhibitors that incorporate details of HIV-1 protease’s function and decrease the probability of drug resistance, are necessary to continue to effectively target this key protein in HIV-1 life cycle.

  6. Inactivation of proteinaceous protease inhibitors of soybeans by isolated fungi

    NARCIS (Netherlands)

    Meijer, M.M.T.; Spekking, W.T.J.; Sijtsma, L.; Bont, de J.A.M.

    1995-01-01

    Proteinaceous protease inhibitors, Kunitz Soybean Trypsin Inhibitor (KSTI) and Bowman Birk Inhibitor (BBI), in legume seeds reduce the digestibility of proteins in feed of monogastric animals. Enzymatic inactivation of these inhibitors will increase the nutritional value of the feed. The aim of this

  7. Breakdown of the innate immune system by bacterial proteases

    NARCIS (Netherlands)

    Laarman, A.J.

    2011-01-01

    Bacteria have developed many strategies to circumvent our immune system to survive and colonize human tissues. One of these strategies is by secreting proteases that specifically target the innate immune system. Aureolysin is a metalloprotease from Staphylococcus aureus which target the main

  8. Manipulating the autolytic pathway of a Bacillus protease

    NARCIS (Netherlands)

    VandenBurg, B; Eijsink, VGH; Vriend, G; Veltman, OR; Venema, G; HopsuHavu, VK; Jarvinen, M; Kirschke, H

    1997-01-01

    Autolytic degradation of Bacillus subtilis thermolysin-like proteinase (TLP-sub) is responsible for the irreversible inactivation of the enzyme at elevated temperatures. Previously, we reported five autolysis sites in B. subtilis neutral protease (Van den Burg et al., 1990, Biochem. J. 272:93-97).

  9. Alkaline protease production by alkaliphilic marine bacteria isolated ...

    African Journals Online (AJOL)

    The molecular mass determined using SDS-PAGE, was nearly 31.0 39 kDa. Some fundamental properties like effects of different temperatures, pH, metal ions (Ca2+, Mg2+, Cu2+, Pb3+, Mn2+ and Cd2+) and ethylene diamine tetraacetic acid (EDTA) on protease activity were also studied. Maximum activities were obtained ...

  10. Alkaline protease from senesced leaves of invasive weed Lantana ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-17

    Dec 17, 2008 ... amongst the most valuable commercial enzyme. Alkaline proteases hold a great potential for application in the detergent and leather industries (Kumar and Takagi,. 1999; Oberoi et al., 2001) due to the increasing trend to develop environmentally friendly technologies. Plants, animals and microbes are the ...

  11. Ionic liquids and proteases: A clean alliance for semisynthesis

    Czech Academy of Sciences Publication Activity Database

    Wehofsky, N.; Wespe, Ch.; Čeřovský, Václav; Pech, A.; Hoess, E.; Rudolph, R.; Bordusa, F.

    2008-01-01

    Roč. 9, č. 9 (2008), s. 1493-1499 ISSN 1439-4227 Grant - others:DFG(DE) SPP1191; DFG(DE) SFB610 Institutional research plan: CEZ:AV0Z40550506 Keywords : chemoenzymatic synthesis * ionic liquids * peptides * proteases * substrate mimetics Subject RIV: CC - Organic Chemistry Impact factor: 3.322, year: 2008

  12. Isolation of protease producing novel Bacillus cereus and detection ...

    African Journals Online (AJOL)

    user

    2011-02-14

    Feb 14, 2011 ... Key words: Protease, production, optimization, Bacillus sp. INTRODUCTION ... Nutrient broth (5 g peptone and 3 g meat extract, pH 7.0, Merck) was used as the common growth ... nitrate through nitrite. It was determined that ...

  13. Activity-Based Protein Profiling of Rhomboid Proteases in Liposomes

    Czech Academy of Sciences Publication Activity Database

    Wolf, E. V.; Seybold, M.; Hadravová, Romana; Stříšovský, Kvido; Verhelst, S. H. L.

    2015-01-01

    Roč. 16, č. 11 (2015), s. 1616-1621 ISSN 1439-4227 R&D Projects: GA MŠk(CZ) LK11206; GA MŠk LO1302 Institutional support: RVO:61388963 Keywords : activity-based protein profiling * chemical probes * inhibitors * intramembrane proteases * liposomes Subject RIV: CE - Biochemistry Impact factor: 2.850, year: 2015

  14. An oxidant, detergent and salt stable alkaline protease from Bacillus ...

    African Journals Online (AJOL)

    A novel soil bacterium, Bacillus cereus SIU1 was earlier isolated from non-saline, slightly alkaline soil of Eastern Uttar Pradesh, India. The isolate B. cereus SIU1 was grown in modified glucose yeast extract (modified GYE) medium at pH 9.0 and 45°C. It produced maximum protease at 20 h incubation. The enzyme was ...

  15. Increasing the alkaline protease activity of Bacillus cereus and ...

    African Journals Online (AJOL)

    User

    2011-05-09

    May 9, 2011 ... cereus and Bacillus polymyxa simultaneously with the start of sporulation phase as a ... microbial forms to inactivation by chemical or physical agents. .... alkaline pH, 9, 10 and 11 and the pH of the culture media was optimized with .... incubation temperature for alkaline protease production by Bacillus ...

  16. Milk Clotting Activity of Protease, Extracted from Rhizome of Taffin ...

    African Journals Online (AJOL)

    MBI

    2017-03-07

    Mar 7, 2017 ... The increasing prices of calf rennets, their accessibility and ethical concerns ... the region with a massive annual production (FAO, ... valuable group of enzymes with various industrial ... use of protease enzymes in the food industry .... In the procedure, Bovine Serum Albumin ..... Agricultural Economics.

  17. Purification and characterization of protease from Bacillus cereus ...

    African Journals Online (AJOL)

    chitti

    2013-09-16

    Sep 16, 2013 ... Purification and characterization of protease from. Bacillus cereus SU12 isolated from oyster. Saccostrea cucullata. S. Umayaparvathi*, S. Meenakshi, M. Arumugam and T. Balasubramanian. Centre of Advanced Study in Marine Biology, Faculty of Marine Sciences, Annamalai University, Parangipettai - 608.

  18. Coxsackievirus B3 2A protease promotes encephalomyocarditis virus replication.

    Science.gov (United States)

    Song, Qin-Qin; Lu, Ming-Zhi; Song, Juan; Chi, Miao-Miao; Sheng, Lin-Jun; Yu, Jie; Luo, Xiao-Nuan; Zhang, Lu; Yao, Hai-Lan; Han, Jun

    2015-10-02

    To determine whether 2A protease of the enterovirus genus with type I internal ribosome entry site (IRES) effect on the viral replication of type II IRES, coxsackievirus B3(CVB3)-encoded protease 2A and encephalomyocarditis virus (EMCV) IRES (Type II)-dependent or cap-dependent report gene were transiently co-expressed in eukaryotic cells. We found that CVB3 2A protease not only inhibited translation of cap-dependent reporter genes through the cleavage of eIF4GI, but also conferred high EMCV IRES-dependent translation ability and promoted EMCV replication. Moreover, deletions of short motif (aa13-18 RVVNRH, aa65-70 KNKHYP, or aa88-93 PRRYQSH) resembling the nuclear localization signals (NLS) or COOH-terminal acidic amino acid motif (aa133-147 DIRDLLWLEDDAMEQ) of CVB3 2A protease decreased both its EMCV IRES-dependent translation efficiency and destroy its cleavage on eukaryotic initiation factor 4G (eIF4G) I. Our results may provide better understanding into more effective interventions and treatments for co-infection of viral diseases. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Targeted degradomics in protein terminomics and protease substrate discovery

    DEFF Research Database (Denmark)

    Savickas, Simonas; auf dem Keller, Ulrich

    2017-01-01

    extensive degradomics target lists that now can be tested with help of selected and parallel reaction monitoring (S/PRM) in complex biological systems, where proteases act in physiological environments. In this minireview, we describe the general principles of targeted degradomics, outline the generic...

  20. The non-death role of metacaspase proteases

    International Nuclear Information System (INIS)

    Shrestha, Amit; Megeney, Lynn A.

    2012-01-01

    The activation of caspase proteases and the targeting of protein substrates act as key steps in the engagement and conduct of apoptosis/programmed cell death. However, the discovery of caspase involvement in diverse non-apoptotic cellular functions strongly suggests that these proteins may have evolved from a core behavior unrelated to the induction of cell death. The presence of similar proteases, termed metacaspases, in single cell organisms supports the contention that such proteins may have co-evolved or derived from a critical non-death function. Indeed, the benefit(s) for single cell life forms to retain proteins solely dedicated to self destruction would be countered by a strong selection pressure to curb or eliminate such processes. Examination of metacaspase biology provides evidence that these ancient protease forerunners of the caspase family also retain versatility in function, i.e., death and non-death cell functions. Here, we provide a critical review that highlights the non-death roles of metacaspases that have been described thus far, and the impact that these observations have for our understanding of the evolution and cellular utility of this protease family.

  1. Purification and characterization of a protease from Thermophilic ...

    African Journals Online (AJOL)

    AJB SERVER

    2006-10-19

    Oct 19, 2006 ... protein liquid chromatography. The method gave a ... gent industry are the proteases from bacteria sources ... In this paper, we report our recent progress on the purification ... 10 to 60 min, then cooled in ice-water and the residue activity was measured .... Huo P, Mao J, Shi Y (2003). ... Kumar CG (2002).

  2. Retroviral proteases and their roles in virion maturation

    Czech Academy of Sciences Publication Activity Database

    Konvalinka, Jan; Kräusslich, H. G.; Müller, B.

    2015-01-01

    Roč. 479, SI (2015), s. 403-417 ISSN 0042-6822 R&D Projects: GA ČR GBP208/12/G016; GA MŠk LO1302 Institutional support: RVO:61388963 Keywords : retrovirus * aspartic protease * maturation * human immunodeficiency virus * Gag Subject RIV: CE - Biochemistry Impact factor: 3.200, year: 2015

  3. Physical and chemical properties of the acid protease from ...

    African Journals Online (AJOL)

    samsung

    2016-03-02

    Mar 2, 2016 ... is the principal set of biochemical changes during ... coagulating ability by analysis of the products of casein ... for protease activity, milk-clotting activity and protein content. ..... Figure 5, the content of casein components decreased in .... Purification, caracterization, molecular cloning and modelling of its.

  4. Extracellular acid protease from Aspergillus niger I1: purification and ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-09-15

    Sep 15, 2009 ... A new strain of Aspergillus niger producing acid protease was isolated and identified by universal primers NL1 and .... Media were autoclaved at 120°C for 20 min. ... molecular weight calibration kit as markers consisting of bovine ... then removed by washing the gel three times with 100 mM ..... New York.

  5. Production of Microbial Protease from Selected Soil Fungal Isolates ...

    African Journals Online (AJOL)

    Production of Microbial Protease from Selected Soil Fungal Isolates. ... Nigerian Journal of Biotechnology ... and 500C. The optimal pH on the enzyme production was observed to be between pH 3.5 and 5.5 for the organisms. Keywords: Soil microorganism, fungal isolate, incubation period, microbial enzyme. Nig J. Biotech.

  6. Serine protease from midgut of Bombus terrestris males

    Czech Academy of Sciences Publication Activity Database

    Brabcová, Jana; Kindl, Jiří; Valterová, Irena; Pichová, Iva; Zarevúcka, Marie; Brabcová, J.; Jágr, Michal; Mikšík, Ivan

    2013-01-01

    Roč. 82, č. 3 (2013), s. 117-128 ISSN 0739-4462 R&D Projects: GA ČR GA203/09/1446; GA TA ČR TA01020969 Institutional support: RVO:61388963 ; RVO:67985823 Keywords : Bombus terrestris * midgut * serine protease * bumblebee Subject RIV: CE - Biochemistry; CE - Biochemistry (FGU-C) Impact factor: 1.160, year: 2013

  7. Optimization of protease production by an actinomycete Strain, PS ...

    African Journals Online (AJOL)

    STORAGESEVER

    distilled water and this was inoculated into 5 ml of gelatin broth and .... leakage. After that, the dialysis bag was suspended in a beaker containing 0.5 M Tris-HCL buffer (pH 8.5) for 24 h, ... the detection of optimum temperature for the protease.

  8. Cleavage of desmin by cysteine proteases: Calpains and cathepsin B

    DEFF Research Database (Denmark)

    Baron, Caroline; Jacobsen, S.; Purslow, P.P.

    2004-01-01

    The intermediate filament protein, desmin, was purified from pork longissimus dorsi and incubated with either P-calpain, m-calpain or cathepsin B. Proteolysis of desmin was followed using SDS-PAGE and Western blotting. After incubation of desmin with the proteases, cleavage sites on the desmin mo...

  9. Production of alkaline protease by Teredinobacter turnirae cells ...

    African Journals Online (AJOL)

    The conditions for immobilizing the new alkaline protease-producing bacteria strain Teredinobacter turnirae by entrapment in calcium alginate gel were investigated. The influence of alginate concentration (20, 25 and 30 g/l) and initial cell loading (ICL) on enzyme production were studied. The production of alkaline ...

  10. Delay of Iris flower senescence by protease inhibitors

    NARCIS (Netherlands)

    Pak, C.; Doorn, van W.G.

    2005-01-01

    asterisk inside a circle sign Visible senescence of the flag tepals in Iris x hollandica (cv. Blue Magic) was preceded by a large increase in endoprotease activity. Just before visible senescence about half of total endoprotease activity was apparently due to cysteine proteases, somewhat less than

  11. molecular biology approach to the search for novel hiv proteases ...

    African Journals Online (AJOL)

    ... which could be tested in the animal models of HIV infection before subjection to clinical trials. Optimistically, the magic HIV therapeutics may be hidden in such insects and may require the application of molecular biology techniques to unravel. KEY WORDS: Antiretroviral drugs, malaria, proteases, restriction enzymes, ...

  12. In-cell protease assay systems based on trans-localizing molecular beacon proteins using HCV protease as a model system.

    Directory of Open Access Journals (Sweden)

    Jeong Hee Kim

    Full Text Available This study describes a sensitive in-cell protease detection system that enables direct fluorescence detection of a target protease and its inhibition inside living cells. This live-cell imaging system provides a fluorescent molecular beacon protein comprised of an intracellular translocation signal sequence, a protease-specific cleavage sequence, and a fluorescent tag sequence(s. The molecular beacon protein is designed to change its intracellular localization upon cleavage by a target protease, i.e., from the cytosol to a subcellular organelle or from a subcellular organelle to the cytosol. Protease activity can be monitored at the single cell level, and accordingly the entire cell population expressing the protease can be accurately enumerated. The clear cellular change in fluorescence pattern makes this system an ideal tool for various life science and drug discovery research, including high throughput and high content screening applications.

  13. Interdependence of Inhibitor Recognition in HIV-1 Protease.

    Science.gov (United States)

    Paulsen, Janet L; Leidner, Florian; Ragland, Debra A; Kurt Yilmaz, Nese; Schiffer, Celia A

    2017-05-09

    Molecular recognition is a highly interdependent process. Subsite couplings within the active site of proteases are most often revealed through conditional amino acid preferences in substrate recognition. However, the potential effect of these couplings on inhibition and thus inhibitor design is largely unexplored. The present study examines the interdependency of subsites in HIV-1 protease using a focused library of protease inhibitors, to aid in future inhibitor design. Previously a series of darunavir (DRV) analogs was designed to systematically probe the S1' and S2' subsites. Co-crystal structures of these analogs with HIV-1 protease provide the ideal opportunity to probe subsite interdependency. All-atom molecular dynamics simulations starting from these structures were performed and systematically analyzed in terms of atomic fluctuations, intermolecular interactions, and water structure. These analyses reveal that the S1' subsite highly influences other subsites: the extension of the hydrophobic P1' moiety results in 1) reduced van der Waals contacts in the P2' subsite, 2) more variability in the hydrogen bond frequencies with catalytic residues and the flap water, and 3) changes in the occupancy of conserved water sites both proximal and distal to the active site. In addition, one of the monomers in this homodimeric enzyme has atomic fluctuations more highly correlated with DRV than the other monomer. These relationships intricately link the HIV-1 protease subsites and are critical to understanding molecular recognition and inhibitor binding. More broadly, the interdependency of subsite recognition within an active site requires consideration in the selection of chemical moieties in drug design; this strategy is in contrast to what is traditionally done with independent optimization of chemical moieties of an inhibitor.

  14. Effects of cysteine protease inhibitors on rabbit cathepsin D maturation

    International Nuclear Information System (INIS)

    Samarel, A.M.; Ferguson, A.G.; Decker, R.S.; Lesch, M.

    1989-01-01

    To examine the effects of cysteine protease inhibitors on cathepsin D intracellular transport, proteolytic processing, and secretion, primary cultures of rabbit cardiac fibroblasts were grown to confluence and exposed to media containing leupeptin, E 64, or chloroquine. Cathepsin D maturation was then evaluated in pulse-chase biosynthetic labeling experiments. None of the three agents affected the charge modification of procathepsin D within the Golgi apparatus. However, all three agents interfered with the subsequent proteolytic processing of procathepsin D isoforms to active cathepsin D. Both leupeptin and E 64 caused the intracellular accumulation of large amounts of a Mr 51,000 processing intermediate. Trace amounts of this intermediate were also detected in chloroquine-treated cells. Combined activity assay and radioimmunoassay of cell lysates indicated that this partially processed form of cathepsin D possessed proteolytic activity. Whereas low medium concentrations of leupeptin (10-100 microM) but not E 64 appeared to stimulate procathepsin D secretion, neither agent appeared to have a major effect on the rate of proenzyme secretion at doses required to inhibit proteolytic maturation (1-10 mM). Furthermore, pretreatment of cells with 10 mM leupeptin appeared only to delay, but not prevent, the intracellular transport of cathepsin D to lysosomes. In contrast, chloroquine increased procathepsin D secretion in a dose-dependent manner, diverting the majority of newly synthesized procathepsin D from the intracellular protease(s) responsible for proteolytic processing. These results suggest that cysteine proteases participate in the proteolytic maturation of procathepsin D during the transport of newly synthesized enzyme to lysosomes, but cysteine protease-mediated proteolytic processing is not required for cathepsin D activation or lysosomal translocation

  15. HIV protease inhibitors in pregnancy : pharmacology and clinical use.

    Science.gov (United States)

    Andany, Nisha; Loutfy, Mona R

    2013-03-01

    The impact of antiretroviral therapy (ART) on the natural history of HIV-1 infection has resulted in dramatic reductions in disease-associated morbidity and mortality. Additionally, the epidemiology of HIV-1 infection worldwide is changing, as women now represent a substantial proportion of infected adults. As more highly effective and tolerable antiretroviral regimens become available, and as the prevention of mother-to-child transmission becomes an attainable goal in the management of HIV-infected individuals, more and more HIV-positive women are choosing to become pregnant and have children. Consequently, it is important to consider the efficacy and safety of antiretroviral agents in pregnancy. Protease inhibitors are a common class of medication used in the treatment of HIV-1 infection and are increasingly being used in pregnancy. However, several studies have raised concerns regarding pharmacokinetic alterations in pregnancy, particularly in the third trimester, which results in suboptimal drug concentrations and a theoretically higher risk of virologic failure and perinatal transmission. Drug level reductions have been observed with each individual protease inhibitor and dose adjustments in pregnancy are suggested for certain agents. Furthermore, studies have also raised concerns regarding the safety of protease inhibitors in pregnancy, particularly as they may increase the risk of pre-term birth and metabolic disturbances. Overall, protease inhibitors are safe and effective for the treatment of HIV-infected pregnant women. Specifically, ritonavir-boosted lopinavir- and atazanavir-based regimens are preferred in pregnancy, while ritonavir-boosted darunavir- and saquinavir-based therapies are reasonable alternatives. This paper reviews the use of protease inhibitors in pregnancy, focusing on pharmacokinetic and safety considerations, and outlines the recommendations for use of this class of medication in the HIV-1-infected pregnant woman.

  16. Transmissible Gastroenteritis Coronavirus Genome Packaging Signal Is Located at the 5′ End of the Genome and Promotes Viral RNA Incorporation into Virions in a Replication-Independent Process

    OpenAIRE

    Morales, Lucia; Mateos-Gomez, Pedro A.; Capiscol, Carmen; del Palacio, Lorena; Enjuanes, Luis; Sola, Isabel

    2013-01-01

    Preferential RNA packaging in coronaviruses involves the recognition of viral genomic RNA, a crucial process for viral particle morphogenesis mediated by RNA-specific sequences, known as packaging signals. An essential packaging signal component of transmissible gastroenteritis coronavirus (TGEV) has been further delimited to the first 598 nucleotides (nt) from the 5′ end of its RNA genome, by using recombinant viruses transcribing subgenomic mRNA that included potential packaging signals. Th...

  17. The gut microbiome and mucosal defenses in cats with coronaviruses: a pilot study

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    Sara Meazzi

    2017-05-01

    Full Text Available Feline Infectious Peritonitis (FIP develops from a mutation of enteric feline coronaviruses (FCoVs and an imbalance of the host immune response. The wide polymorphism of FCoVs is associated with the viral replication rate (Licitra et al. 2013.  Changes in the composition of the gut microbiota may induce quali-quantitative modifications in FCoVs and/or different immune profiles (Weese et al., 2015. Few information is available on feline gut microbiome and the association between microbiota and the predisposition to pathological conditions (Ramadan et al., 2014. The aim of this study is to provide preliminary data about the composition of gut microbiota in healthy cats compared with FCoV infected cats (with and without  FIP, in order to evaluate whether changes of gut microbiota may induce changes in FCoV, in its genetic polymorphism and in the mucosal immunity. Screening analyses have been performed on 22 cats: - Routine hematology and biochemistry on EDTA and serum (included electrophoresis and alpha-1-acid glycoprotein measurement for cats suspected with FIP - Nested RT-PCR-3’UTR on frozen faeces - Effusion evaluation - FIV/FeLV serology Due to strict inclusion criteria (cats younger than 2.5 years old, indoor and not assuming antibiotics in the previous two months and based on the results obtained from the complete set of analysis, only 15 cats, specifically 5 cats for each of the following 3 groups: FIP- affected, healthy negative and positive for FCoV, have been recruited to perform the following analyses:  - microbiota analysis through NGS of 16S rRNA gene (V4 region amplicons followed by bioinformatic analysis  -  evaluation of secretory IgA (ELISA kit - phylogenetic analysis of FCoVs S gene sequences Innovative results will be provided on the feline gut microbiota composition. These will be correlated with the presence and genetic polymorphisms of FCoV and mucosal defenses to establish significant correlations between the analysed

  18. Seroprevalence study of feline coronavirus in owned and feral cats in Sydney, Australia.

    Science.gov (United States)

    Bell, E T; Toribio, J A L M L; White, J D; Malik, R; Norris, J M

    2006-03-01

    i) To establish the seroprevalence of Feline Coronavirus (FCoV) infection in two defined groups of cats in Sydney: owned and feral cats; ii) to identify factors associated with an increased risk of infection with FCoV; and iii) to establish the seroprevalence and FCoV antibody titres of owned cats with immunohistochemically confirmed feline infectious peritonitis (FIP). Prospective multi-institutional cross sectional study. Procedure Serum samples from owned cats presented to three inner city veterinary clinics in Sydney and feral cats from a colony in South Western Sydney over an 11-month period were tested for FCoV antibodies using the Immunocomb test kit. The relationship between serological score and six major factors (breed, age, gender, number of cats per household, living environment and health status) in the owned cat sample population was analysed and compared to cats with FIR RESULTS: The seroprevalence of FCoV infection in the sample population of owned and feral cats was 34% and 0%, respectively. The median Immunocomb scores of DSH, Persian, Siamese and Devon Rex cats were significantly lower than that of Burmese, BSH, Abyssinian, Birman, Ragdoll and Russian Blue. The median lmmunocomb score of pedigree cats less than 2 years-of-age was significantly higher than for pedigree cats greater than 2 years-of-age. This distinction was not evident in DSH cats in these age groups. The number of cats per household at the time of blood collection had a strong positive association with Immunocomb score. The median Immunocomb score of cats with immunohistochemically confirmed FIP was significantly higher than cats in the sample population of owned cats but there was sufficient overlap between these two groups to make definitive diagnosis of FIP by serology impossible. This represents the first seroprevalence study of FCoV in Australia. The major determinants of antibody score of owned cats identified in this study were breed, age and the number of cats per

  19. Detection of feline coronavirus spike gene mutations as a tool to diagnose feline infectious peritonitis.

    Science.gov (United States)

    Felten, Sandra; Weider, Karola; Doenges, Stephanie; Gruendl, Stefanie; Matiasek, Kaspar; Hermanns, Walter; Mueller, Elisabeth; Matiasek, Lara; Fischer, Andrea; Weber, Karin; Hirschberger, Johannes; Wess, Gerhard; Hartmann, Katrin

    2017-04-01

    Objectives Feline infectious peritonitis (FIP) is an important cause of death in the cat population worldwide. The ante-mortem diagnosis of FIP in clinical cases is still challenging. In cats without effusion, a definitive diagnosis can only be achieved post mortem or with invasive methods. The aim of this study was to evaluate the use of a combined reverse transcriptase nested polymerase chain reaction (RT-nPCR) and sequencing approach in the diagnosis of FIP, detecting mutations at two different nucleotide positions within the spike (S) gene. Methods The study population consisted of 64 cats with confirmed FIP and 63 cats in which FIP was initially suspected due to similar clinical or laboratory signs, but that were definitively diagnosed with another disease. Serum/plasma and/or effusion samples of these cats were examined for feline coronavirus (FCoV) RNA by RT-nPCR and, if positive, PCR products were sequenced for nucleotide transitions within the S gene. Results Specificity of RT-nPCR was 100% in all materials (95% confidence interval [CI] in serum/plasma 83.9-100.0; 95% CI in effusion 93.0-100.0). The specificity of the sequencing step could not be determined as none of the cats of the control group tested positive for FCoV RNA. Sensitivity of the 'combined RT-nPCR and sequencing approach' was 6.5% (95% CI 0.8-21.4) in serum/plasma and 65.3% (95% CI 50.4-78.3) in effusion. Conclusions and relevance A positive result is highly indicative of the presence of FIP, but as none of the control cats tested positive by RT-nPCR, it was not possible to confirm that the FCoV mutant described can only be found in cats with FIP. Further studies are necessary to evaluate the usefulness of the sequencing step including FCoV-RNA-positive cats with and without FIP. A negative result cannot be used to exclude the disease, especially when only serum/plasma samples are available.

  20. Bovine coronavirus in naturally and experimentally exposed calves; viral shedding and the potential for transmission.

    Science.gov (United States)

    Oma, Veslemøy Sunniva; Tråvén, Madeleine; Alenius, Stefan; Myrmel, Mette; Stokstad, Maria

    2016-06-13

    Bovine coronavirus (BCoV) is a widely distributed pathogen, causing disease and economic losses in the cattle industry worldwide. Prevention of virus spread is impeded by a lack of basic knowledge concerning viral shedding and transmission potential in individual animals. The aims of the study were to investigate the duration and quantity of BCoV shedding in feces and nasal secretions related to clinical signs, the presence of virus in blood and tissues and to test the hypothesis that seropositive calves are not infectious to naïve in-contact calves three weeks after BCoV infection. A live animal experiment was conducted, with direct contact between animal groups for 24 h as challenge procedure. Four naïve calves were commingled with a group of six naturally infected calves and sequentially euthanized. Two naïve sentinel calves were commingled with the experimentally exposed group three weeks after exposure. Nasal swabs, feces, blood and tissue samples were analyzed for viral RNA by RT-qPCR, and virus isolation was performed on nasal swabs. Serum was analyzed for BCoV antibodies. The calves showed mild general signs, and the most prominent signs were from the respiratory system. The overall clinical score corresponded well with the shedding of viral RNA the first three weeks after challenge. General depression and cough were the signs that correlated best with shedding of BCoV RNA, while peak respiratory rate and peak rectal temperature appeared more than a week later than the peak shedding. Nasal shedding preceded fecal shedding, and the calves had detectable amounts of viral RNA intermittently in feces through day 35 and in nasal secretions through day 28, however virus isolation was unsuccessful from day six and day 18 from the two calves investigated. Viral RNA was not detected in blood, but was found in lymphatic tissue through day 42 after challenge. Although the calves were shedding BCoV RNA 21 days after infection the sentinel animals were not infected

  1. Epidemiology of human coronavirus NL63 infection among hospitalized patients with pneumonia in Taiwan.

    Science.gov (United States)

    Huang, Su-Hua; Su, Mei-Chi; Tien, Ni; Huang, Chien-Jhen; Lan, Yu-Ching; Lin, Chen-Sheng; Chen, Chao-Hsien; Lin, Cheng-Wen

    2017-12-01

    Human coronavirus (HCoV) NL63 is recognized in association with upper or lower respiratory tract illnesses in children. This study surveyed the prevalence of HCoV-NL63 and influenza viruses in patients with influenza-like illness in Taiwan during 2010-2011. Throat samples from 107 hospitalized patients with pneumonia and 175 outpatients with influenza-like illness were examined using real-time polymerase chain reaction assays with virus-specific primers, and then virus-positive specimens were confirmed by sequencing the polymerase chain reaction products. HCoV-NL63 infection was identified in 8.4% (9/107) of hospitalized patients with pneumonia, but not found in outpatients with influenza-like illness. Age distribution of HCoV-NL63 infection in hospitalized patients with pneumonia indicated that the group aged 16-25 years (20%) had the highest positive rate compared with the other groups, and exhibited a similar age-specific pattern to influenza A/H1N1 infection, but not influenza A/H3N2 and B infections in hospitalized patients. Seasonal prevalence of HCoV-NL63 infection was late winter, overlapping the highest peak of the influenza A/H1N1 epidemic during December 2010 to March 2011 in Taiwan. Co-infection of HCoV-NL63 and influenza A/H1N1 was detected in three hospitalized patients. Clinical manifestation analysis indicated that the main symptoms for HCoV-NL63 infection included fever (88.9%), cough (77.8%), and pneumonia (100%). Co-infection caused significantly higher rates of breathing difficulties, cough, and sore throat than those of single infection with HCoV-NL63 and influenza A/H1N1. Phylogenetic analysis indicated a low level of heterogeneity between Taiwan and global HCoV-NL63 strains. Understanding epidemiology of HCoV-NL63 in Taiwan provides an insight for worldwide surveillance of HCoV-NL63 infection. Copyright © 2015. Published by Elsevier B.V.

  2. Middle East respiratory syndrome coronavirus transmission among health care workers: Implication for infection control.

    Science.gov (United States)

    Alfaraj, Sarah H; Al-Tawfiq, Jaffar A; Altuwaijri, Talal A; Alanazi, Marzouqa; Alzahrani, Nojoom; Memish, Ziad A

    2018-02-01

    Many outbreaks of Middle East respiratory syndrome coronavirus (MERS-CoV) have occurred in health care settings and involved health care workers (HCWs). We describe the occurrence of an outbreak among HCWs and attempt to characterize at-risk exposures to improve future infection control interventions. This study included an index case and all HCW contacts. All contacts were screened for MERS-CoV using polymerase chain reaction. During the study period in 2015, the index case was a 30-year-old Filipino nurse who had a history of unprotected exposure to a MERS-CoV-positive case on May 15, 2015, and had multiple negative tests for MERS-CoV. Weeks later, she was diagnosed with pulmonary tuberculosis and MERS-CoV infection. A total of 73 staff were quarantined for 14 days, and nasopharyngeal swabs were taken on days 2, 5, and 12 postexposure. Of those contacts, 3 (4%) were confirmed positive for MERS-CoV. An additional 18 staff were quarantined and had MERS-CoV swabs. A fourth case was confirmed positive on day 12. Subsequent contact investigations revealed a fourth-generation transmission. Only 7 (4.5%) of the total 153 contacts were positive for MERS-CoV. The role of HCWs in MERS-CoV transmission is complex. Although most MERS-CoV-infected HCWs are asymptomatic or have mild disease, fatal infections can occur and HCWs can play a major role in propagating health care facility outbreaks. This investigation highlights the need to continuously review infection control guidance relating to the role of HCWs in MERS-CoV transmission in health care outbreaks, especially as it relates to the complex questions on definition of risky exposures, who to test, and the frequency of MERS-CoV testing; criteria for who to quarantine and for how long; and clearance and return to active duty criteria. Copyright © 2018 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  3. A role in immunity for Arabidopsis cysteine protease RD21, the ortholog of the tomato immune protease C14.

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    Takayuki Shindo

    Full Text Available Secreted papain-like Cys proteases are important players in plant immunity. We previously reported that the C14 protease of tomato is targeted by cystatin-like EPIC proteins that are secreted by the oomycete pathogen Phytophthora infestans (Pinf during infection. C14 has been under diversifying selection in wild potato species coevolving with Pinf and reduced C14 levels result in enhanced susceptibility for Pinf. Here, we investigated the role C14-EPIC-like interactions in the natural pathosystem of Arabidopsis with the oomycete pathogen Hyaloperonospora arabidopsidis (Hpa. In contrast to the Pinf-solanaceae pathosystem, the C14 orthologous protease of Arabidopsis, RD21, does not evolve under diversifying selection in Arabidopsis, and rd21 null mutants do not show phenotypes upon compatible and incompatible Hpa interactions, despite the evident lack of a major leaf protease. Hpa isolates express highly conserved EPIC-like proteins during infections, but it is unknown if these HpaEPICs can inhibit RD21 and one of these HpaEPICs even lacks the canonical cystatin motifs. The rd21 mutants are unaffected in compatible and incompatible interactions with Pseudomonas syringae pv. tomato, but are significantly more susceptible for the necrotrophic fungal pathogen Botrytis cinerea, demonstrating that RD21 provides immunity to a necrotrophic pathogen.

  4. Some Investigations on Protease Enzyme Production Kinetics Using Bacillus licheniformis BBRC 100053 and Effects of Inhibitors on Protease Activity

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    Zahra Ghobadi Nejad

    2014-01-01

    Full Text Available Due to great commercial application of protease, it is necessary to study kinetic characterization of this enzyme in order to improve design of enzymatic reactors. In this study, mathematical modeling of protease enzyme production kinetics which is derived from Bacillus licheniformis BBRC 100053 was studied (at 37°C, pH 10 after 73 h in stationary phase, and 150 rpm. The aim of the present paper was to determine the best kinetic model and kinetic parameters for production of protease and calculating Ki (inhibition constant of different inhibitors to find the most effective one. The kinetic parameters Km (Michaelis-Menten constant and Vm (maximum rate were calculated 0.626 mM and 0.0523 mM/min. According to the experimental results, using DFP (diisopropyl fluorophosphate and PMSF (phenylmethanesulfonyl fluoride as inhibitors almost 50% of the enzyme activity could be inhibited when their concentrations were 0.525 and 0.541 mM, respectively. Ki for DFP and PMSF were 0.46 and 0.56 mM, respectively. Kinetic analysis showed that the Lineweaver-Burk model was the best fitting model for protease production kinetics DFP was more effective than PMSF and both of them should be covered in the group of noncompetitive inhibitors.

  5. Characterization of the Protease Activity of Detergents: Laboratory Practicals for Studying the Protease Profile and Activity of Various Commercial Detergents

    Science.gov (United States)

    Valls, Cristina; Pujadas, Gerard; Garcia-Vallve, Santi; Mulero, Miquel

    2011-01-01

    Detergent enzymes account for about 30% of the total worldwide production of enzymes and are one of the largest and most successful applications of modern industrial biotechnology. Proteases can improve the wash performance of household, industrial, and institutional laundry detergents used to remove protein-based stains such as blood, grass, body…

  6. Identification of cysteine proteases and screening of cysteine protease inhibitors in biological samples by a two-dimensional gel system of zymography and reverse zymography.

    Science.gov (United States)

    Saitoh, Eiichi; Yamamoto, Shinya; Okamoto, Eishiro; Hayakawa, Yoshimi; Hoshino, Takashi; Sato, Ritsuko; Isemura, Satoko; Ohtsubo, Sadami; Taniguchi, Masayuki

    2007-11-18

    We have developed a two-dimensional (2D-) gel system of zymography and reverse zymography for the detection and characterization of proteases and protease inhibitors. Isoelectric focusing (IEF) agarose gels with pH gradients were employed for separation in the first-dimension and sodium dodecyl sulfate (SDS)-polyacrylamide gel copolymerized with gelatin used for the second dimension. Proteases and protease inhibitors separated by IEF gel were applied on the second gel without trichloroacetic acid (TCA) fixation. Protease activity in the 2D-gel was visualized as transparent spots where gelatin substrate was digested after commassie brilliant blue (CBB) staining. Some of the transparent spots from the skin mucus extract of rainbow trout were determined to be a cysteine protease through use of E-64 or CA-074. In the reverse zymography technique, the gel was incubated with papain solution at 37 degrees C for 18 h. Cysteine protease inhibitors from broad bean seeds were detected as clear blue spots after CBB staining. The amino (N-) terminal sequences of four papain inhibitor spots thus detected were demonstrated to be identical to that of favin beta chain, a broad bean lectin. Taken together, our system can be considered to be an efficient technique for discovering and characterizing new proteases and protease inhibitors in biological samples. This is the first report describing a 2D-gel system of zymography and reverse zymography.

  7. The SARS-unique domain (SUD of SARS coronavirus contains two macrodomains that bind G-quadruplexes.

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    Jinzhi Tan

    2009-05-01

    Full Text Available Since the outbreak of severe acute respiratory syndrome (SARS in 2003, the three-dimensional structures of several of the replicase/transcriptase components of SARS coronavirus (SARS-CoV, the non-structural proteins (Nsps, have been determined. However, within the large Nsp3 (1922 amino-acid residues, the structure and function of the so-called SARS-unique domain (SUD have remained elusive. SUD occurs only in SARS-CoV and the highly related viruses found in certain bats, but is absent from all other coronaviruses. Therefore, it has been speculated that it may be involved in the extreme pathogenicity of SARS-CoV, compared to other coronaviruses, most of which cause only mild infections in humans. In order to help elucidate the function of the SUD, we have determined crystal structures of fragment 389-652 ("SUD(core" of Nsp3, which comprises 264 of the 338 residues of the domain. Both the monoclinic and triclinic crystal forms (2.2 and 2.8 A resolution, respectively revealed that SUD(core forms a homodimer. Each monomer consists of two subdomains, SUD-N and SUD-M, with a macrodomain fold similar to the SARS-CoV X-domain. However, in contrast to the latter, SUD fails to bind ADP-ribose, as determined by zone-interference gel electrophoresis. Instead, the entire SUD(core as well as its individual subdomains interact with oligonucleotides known to form G-quadruplexes. This includes oligodeoxy- as well as oligoribonucleotides. Mutations of selected lysine residues on the surface of the SUD-N subdomain lead to reduction of G-quadruplex binding, whereas mutations in the SUD-M subdomain abolish it. As there is no evidence for Nsp3 entering the nucleus of the host cell, the SARS-CoV genomic RNA or host-cell mRNA containing long G-stretches may be targets of SUD. The SARS-CoV genome is devoid of G-stretches longer than 5-6 nucleotides, but more extended G-stretches are found in the 3'-nontranslated regions of mRNAs coding for certain host-cell proteins

  8. The threonine protease activity of testes-specific protease 50 (TSP50 is essential for its function in cell proliferation.

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    Yu-Yin Li

    Full Text Available BACKGROUND: Testes-specific protease 50 (TSP50, a newly discovered threonine enzyme, has similar amino acid sequences and enzymatic structures to those of many serine proteases. It may be an oncogene. TSP50 is up-regulated in breast cancer epithelial cells, and ectopic expression of TSP50 in TSP50-deficient Chinese hamster ovary (CHO cells has been found to promote cell proliferation. However, the mechanisms by which TSP50 exerts its growth-promoting effects are not yet fully understood. METHODOLOGY/PRINCIPAL FINDINGS: To delineate whether the threonine protease activity of TSP50 is essential to its function in cell proliferation, we constructed and characterized a mutant TSP50, called TSP50 T310A, which was identified as a protease-dead mutant of TSP50. By a series of proliferation analyses, colony formation assays and apoptosis analyses, we showed that T310A mutation significantly depresses TSP50-induced cell proliferation in vitro. Next, the CHO stable cell line expressing either wild-type or T310A mutant TSP50 was injected subcutaneously into nude mice. We found that the T310A mutation could abolish the tumorigenicity of TSP50 in vivo. A mechanism investigation revealed that the T310A mutation prevented interaction between TSP50 and the NF-κBIκBα complex, which is necessary for TSP50 to perform its function in cell proliferation. CONCLUSION: Our data highlight the importance of threonine 310, the most critical protease catalytic site in TSP50, to TSP50-induced cell proliferation and tumor formation.

  9. Proteases in Escherichia coli and Staphylococcus aureus confer reduced susceptibility to lactoferricin B.

    Science.gov (United States)

    Ulvatne, Hilde; Haukland, Hanne Husom; Samuelsen, Ørjan; Krämer, Manuela; Vorland, Lars H

    2002-10-01

    Lactoferricin B is a cationic antimicrobial peptide derived from the N-terminal part of bovine lactoferrin. The effect of bacterial proteases on the antibacterial activity of lactoferricin B towards Escherichia coli and Staphylococcus aureus was investigated using various protease inhibitors and protease-deficient E. coli mutants. Sodium-EDTA, a metalloprotease inhibitor, was the most efficient inhibitors in both species, but combinations of sodium-EDTA with other types of protease inhibitor gave a synergic effect. The results indicate that several groups of proteases are involved in resistance to lactoferricin B in both E. coli and S. aureus. We also report that genetic inactivation of the heat shock-induced serine protease DegP increased the susceptibility to lactoferricin B in E. coli, suggesting that this protease, at least, is involved in reduced susceptibility to lactoferricin B.

  10. Production and partial characterization of alkaline protease from bacillus subtilis mutant induced by gamma radiation

    International Nuclear Information System (INIS)

    Ibrahim, H.M.M.; Bashandy, A.S.

    2010-01-01

    Fourteen bacterial isolates belonging to B.subtilis were locally isolated from soil and screened for alkaline protease production. Only one strain, the highly potent one, was selected as alkaline protease producer and subjected to further studies to optimize its production. Alkaline protease production was maximum at 35 degree C after 72 h of incubation and at ph 10.0. molasses as a carbon source and combination of peptone and yeast extract as a nitrogen source enhanced greatly alkaline protease production. The mutant strain induced by gamma radiation showed higher alkaline protease production by 1.97 fold as compared with the parent strain. The alkaline protease enzyme was active at 40 degree C and ph 10. It was compatible with many commercial detergents and showed high stability (84 %) of its original activity with Ariel detergent. Moreover, alkaline protease enhanced the washing performance, and retained 95 % of its activity in the formulated dry powder.

  11. Kinetic intermediates en route to the final serpin-protease complex: studies of complexes of α1-protease inhibitor with trypsin.

    Science.gov (United States)

    Maddur, Ashoka A; Swanson, Richard; Izaguirre, Gonzalo; Gettins, Peter G W; Olson, Steven T

    2013-11-01

    Serpin protein protease inhibitors inactivate their target proteases through a unique mechanism in which a major serpin conformational change, resulting in a 70-Å translocation of the protease from its initial reactive center loop docking site to the opposite pole of the serpin, kinetically traps the acyl-intermediate complex. Although the initial Michaelis and final trapped acyl-intermediate complexes have been well characterized structurally, the intermediate stages involved in this remarkable transformation are not well understood. To better characterize such intermediate steps, we undertook rapid kinetic studies of the FRET and fluorescence perturbation changes of site-specific fluorophore-labeled derivatives of the serpin, α1-protease inhibitor (α1PI), which report the serpin and protease conformational changes involved in transforming the Michaelis complex to the trapped acyl-intermediate complex in reactions with trypsin. Two kinetically resolvable conformational changes were observed in the reactions, ascribable to (i) serpin reactive center loop insertion into sheet A with full protease translocation but incomplete protease distortion followed by, (ii) full conformational distortion and movement of the protease and coupled serpin conformational changes involving the F helix-sheet A interface. Kinetic studies of calcium effects on the labeled α1PI-trypsin reactions demonstrated both inactive and low activity states of the distorted protease in the final complex that were distinct from the intermediate distorted state. These studies provide new insights into the nature of the serpin and protease conformational changes involved in trapping the acyl-intermediate complex in serpin-protease reactions and support a previously proposed role for helix F in the trapping mechanism.

  12. Virological and serological analysis of a recent Middle East respiratory syndrome coronavirus infection case on a triple combination antiviral regimen.

    Science.gov (United States)

    Spanakis, Nikolaos; Tsiodras, Sotirios; Haagmans, Bart L; Raj, V Stalin; Pontikis, Kostantinos; Koutsoukou, Antonia; Koulouris, Nikolaos G; Osterhaus, Albert D M E; Koopmans, Marion P G; Tsakris, Athanassios

    2014-12-01

    Serological, molecular and phylogenetic analyses of a recently imported case of Middle East respiratory syndrome coronavirus (MERS-CoV) in Greece are reported. Although MERS-CoV remained detectable in the respiratory tract secretions of the patient until the fourth week of illness, viraemia was last detected 2 days after initiation of triple combination therapy with pegylated interferon, ribavirin and lopinavir/ritonavir, administered from Day 13 of illness. Phylogenetic analysis of the virus showed close similarity with other human MERS-CoVs from the recent Jeddah outbreak in Saudi Arabia. Immunoglobulin G (IgG) titres peaked 3 weeks after the onset of illness, whilst IgM levels remained constantly elevated during the follow-up period (second to fifth week of illness). Serological testing confirmed by virus neutralisation assay detected an additional case that was a close contact of the patient. Copyright © 2014. Published by Elsevier B.V.

  13. Detection and genetic characterization of Canine parvovirus and Canine coronavirus strains circulating in district of Tirana in Albania.

    Science.gov (United States)

    Cavalli, Alessandra; Desario, Costantina; Kusi, Ilir; Mari, Viviana; Lorusso, Eleonora; Cirone, Francesco; Kumbe, Ilirjan; Colaianni, Maria Loredana; Buonavoglia, Domenico; Decaro, Nicola

    2014-07-01

    An epidemiological survey for Canine parvovirus 2 (CPV-2) and Canine coronavirus (CCoV) was conducted in Albania. A total of 57 fecal samples were collected from diarrheic dogs in the District of Tirana during 2011-2013. The molecular assays detected 53 and 31 CPV- and CCoV-positive specimens, respectively, with mixed CPV-CCoV infections diagnosed in 28 dogs. The most frequently detected CPV type was 2a, whereas IIa was the predominant CCoV subtype. A better comprehension of the CPV-CCoV epidemiology in eastern European countries will help to assess the most appropriate vaccination strategies to prevent disease due to infections with these widespread agents of acute gastroenteritis in the dog.

  14. Co-circulation of three camel coronavirus species and recombination of MERS-CoVs in Saudi Arabia.

    Science.gov (United States)

    Sabir, Jamal S M; Lam, Tommy T-Y; Ahmed, Mohamed M M; Li, Lifeng; Shen, Yongyi; Abo-Aba, Salah E M; Qureshi, Muhammd I; Abu-Zeid, Mohamed; Zhang, Yu; Khiyami, Mohammad A; Alharbi, Njud S; Hajrah, Nahid H; Sabir, Meshaal J; Mutwakil, Mohammed H Z; Kabli, Saleh A; Alsulaimany, Faten A S; Obaid, Abdullah Y; Zhou, Boping; Smith, David K; Holmes, Edward C; Zhu, Huachen; Guan, Yi

    2016-01-01

    Outbreaks of Middle East respiratory syndrome (MERS) raise questions about the prevalence and evolution of the MERS coronavirus (CoV) in its animal reservoir. Our surveillance in Saudi Arabia in 2014 and 2015 showed that viruses of the MERS-CoV species and a human CoV 229E-related lineage co-circulated at high prevalence, with frequent co-infections in the upper respiratory tract of dromedary camels. viruses of the betacoronavirus 1 species, we found that dromedary camels share three CoV species with humans. Several MERS-CoV lineages were present in camels, including a recombinant lineage that has been dominant since December 2014 and that subsequently led to the human outbreaks in 2015. Camels therefore serve as an important reservoir for the maintenance and diversification of the MERS-CoVs and are the source of human infections with this virus. Copyright © 2016, American Association for the Advancement of Science.

  15. Overview of preparedness and response for Middle East respiratory syndrome coronavirus (MERS-CoV in Oman

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    I.S. Al-Abaidani

    2014-12-01

    Full Text Available Several countries in the Middle East and around 22 countries worldwide have reported cases of human infection with the Middle East respiratory syndrome coronavirus (MERS-CoV. The exceptionally high fatality rate resulting from MERS-CoV infection in conjunction with the paucity of knowledge about this emerging virus has led to major public and international concern. Within the framework of the national acute respiratory illness surveillance, the Ministry of Health in the Sultanate of Oman has announced two confirmed cases of MERS-CoV to date. The aim of this report is to describe the epidemiological aspects of these two cases and to highlight the importance of public health preparedness and response. The absence of secondary cases among contacts of the reported cases can be seen as evidence of the effectiveness of infection prevention and control precautions as an important pillar of the national preparedness and response plan applied in the health care institutions in Oman.

  16. Knowledge and attitude towards the Middle East respiratory syndrome coronavirus among healthcare personnel in the southern region of Saudi Arabia.

    Science.gov (United States)

    Abbag, Huda F; El-Mekki, Awad Ahmed; Al Bshabshe, Ali Aobaid Ali; Mahfouz, Ahmed A; Al-Dosry, Ahasen A; Mirdad, Rasha T; AlKhttabi, Nora F; Abbag, Lubna F

    2018-03-07

    Middle East respiratory syndrome coronavirus (MERS-CoV) belongs to the family Coronaviridae, and is named for the crown-like spikes on its surface. The clinical presentation of MERS-CoV infection ranges from asymptomatic to very severe disease, and the classical presentation includes fever, cough chills, sore throat, myalgia, and arthralgia. A cross-sectional study of 339 healthcare personnel was conducted over an 8-month period in the Aseer region of Saudi Arabia using a structured survey that included demographic information and questions testing participant's knowledge. Approximately two-thirds of the respondents properly identified the causative agent of MERS-CoV as an RNA virus (66.4%, n=225) that is enveloped (68.1%, n=231). On the other hand, few respondents identified the proper number of strains or the genus (16.5% and 17.4%, respectively). More than half of the study sample identified the disease as zoonotic (57.2%, n=194). Similarly, 89.1% (n=302) identified that camels and bats are prone to infection with coronaviruses. Only 23.9% (n=81) properly identified March through May as the season with the highest transmission rate. There was a massive lack of adequate knowledge regarding prevalence of antibodies. Only 18.3% (n=62) of respondents identified PCR as the proper diagnostic confirmatory test for MERS-CoV infection. Regarding MERS-CoV clinical features, 76.4% (n=259) recognized the presence of sub-clinical infection, 64.7% (n=218) indicated that cases should be immediately isolated, and 46.9% (n=159) identified the main cause of mortality as respiratory failure. There is limited microbiological and virological knowledge of MERS-CoV infection among healthcare personnel in the southern region of Saudi Arabia, although the clinical aspects are known. Copyright © 2018. Published by Elsevier Ltd.

  17. Feline coronavirus quantitative reverse transcriptase polymerase chain reaction on effusion samples in cats with and without feline infectious peritonitis.

    Science.gov (United States)

    Longstaff, Louise; Porter, Emily; Crossley, Victoria J; Hayhow, Sophie E; Helps, Christopher R; Tasker, Séverine

    2017-02-01

    Objectives The aim of the study was to determine whether feline coronavirus (FCoV) RNA in effusion samples can be used as a diagnostic marker of feline infectious peritonitis (FIP); and in FCoV RNA-positive samples to examine amino acid codons in the FCoV spike protein at positions 1058 and 1060 where leucine and alanine, respectively, have been associated with systemic or virulent (FIP) FCoV infection. Methods Total RNA was extracted from effusion samples from 20 cats with confirmed FIP and 23 cats with other diseases. Feline coronavirus RNA was detected using a reverse transcriptase quantitative polymerase chain reaction assay (qRT-PCR), and positive samples underwent pyrosequencing of position 1058 with or without Sanger sequencing of position 1060 in the FCoV spike protein. Results Seventeen (85%) of the effusion samples from 20 cats with FIP were positive for FCoV RNA, whereas none of the 23 cats with other diseases were positive. Pyrosequencing of the 17 FCoV-positive samples showed that 11 (65%) of the cats had leucine and two (12%) had methionine at position 1058. Of the latter two samples with methionine, one had alanine at position 1060. Conclusions and relevance A positive FCoV qRT-PCR result on effusions appears specific for FIP and may be a useful diagnostic marker for FIP in cats with effusions. The majority of FCoVs contained amino acid changes previously associated with systemic spread or virulence (FIP) of the virus.

  18. Structural Analysis of Major Species Barriers between Humans and Palm Civets for Severe Acute Respiratory Syndrome Coronavirus Infections

    Energy Technology Data Exchange (ETDEWEB)

    Li, Fang (UMM)

    2008-09-23

    It is believed that a novel coronavirus, severe acute respiratory syndrome coronavirus (SARS-CoV), was passed from palm civets to humans and caused the epidemic of SARS in 2002 to 2003. The major species barriers between humans and civets for SARS-CoV infections are the specific interactions between a defined receptor-binding domain (RBD) on a viral spike protein and its host receptor, angiotensin-converting enzyme 2 (ACE2). In this study a chimeric ACE2 bearing the critical N-terminal helix from civet and the remaining peptidase domain from human was constructed, and it was shown that this construct has the same receptor activity as civet ACE2. In addition, crystal structures of the chimeric ACE2 complexed with RBDs from various human and civet SARS-CoV strains were determined. These structures, combined with a previously determined structure of human ACE2 complexed with the RBD from a human SARS-CoV strain, have revealed a structural basis for understanding the major species barriers between humans and civets for SARS-CoV infections. They show that the major species barriers are determined by interactions between four ACE2 residues (residues 31, 35, 38, and 353) and two RBD residues (residues 479 and 487), that early civet SARS-CoV isolates were prevented from infecting human cells due to imbalanced salt bridges at the hydrophobic virus/receptor interface, and that SARS-CoV has evolved to gain sustained infectivity for human cells by eliminating unfavorable free charges at the interface through stepwise mutations at positions 479 and 487. These results enhance our understanding of host adaptations and cross-species infections of SARS-CoV and other emerging animal viruses.

  19. Cardiovascular disease and use of contemporary protease inhibitors

    DEFF Research Database (Denmark)

    Ryom, Lene; Lundgren, Jens D; El-Sadr, Wafaa

    2018-01-01

    BACKGROUND: Although earlier protease inhibitors have been associated with increased risk of cardiovascular disease, whether this increased risk also applies to more contemporary protease inhibitors is unknown. We aimed to assess whether cumulative use of ritonavir-boosted atazanavir and ritonavir......-boosted darunavir were associated with increased incidence of cardiovascular disease in people living with HIV. METHODS: The prospective Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study consists of people living with HIV-1 from 11 cohorts in Australia, Europe, and the USA. Participants were...... monitored from Jan 1, 2009, until the earliest of a cardiovascular event, 6 months after the last visit, or until Feb 1, 2016. The outcome of interest was the incidence of cardiovascular disease in adults (aged ≥16 years) living with HIV who were being treated with contemporary treatments. We defined...

  20. Advances in zymography techniques and patents regarding protease analysis.

    Science.gov (United States)

    Wilkesman, Jeff; Kurz, Liliana

    2012-08-01

    Detection of enzymatic activity on gel electrophoresis, namely zymography, is a technique that has received increasing attention in the last 10 years, according to the number of articles published. A growing amount of enzymes, mainly proteases, are now routinely detected by zymography. Detailed analytical studies are beginning to be published, as well as new patents have been developed. This new article updates the information covered in our last review, condensing the recent publications dealing with the identification of proteolytic enzymes in electrophoretic gel supports and its variations. The new advances of this method are basically focused towards two dimensional zymography and transfer zymography. Though comparatively fewer patents have been published, they basically coincide in the study of matrix metalloproteases. The tendency is foreseen to be very productive in the area of zymoproteomics, combining electrophoresis and mass spectrometry for the analysis of proteases.