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

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

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.

Effects of amantadine on the dynamics of membrane-bound influenza A M2 transmembrane peptide studied by NMR relaxation

Energy Technology Data Exchange (ETDEWEB)

Cady, Sarah D.; Hong Mei [Iowa State University, Department of Chemistry (United States)], E-mail: mhong@iastate.edu

2009-09-15

The molecular motions of membrane proteins in liquid-crystalline lipid bilayers lie at the interface between motions in isotropic liquids and in solids. Specifically, membrane proteins can undergo whole-body uniaxial diffusion on the microsecond time scale. In this work, we investigate the {sup 1}H rotating-frame spin-lattice relaxation (T{sub 1{rho}}) caused by the uniaxial diffusion of the influenza A M2 transmembrane peptide (M2TMP), which forms a tetrameric proton channel in lipid bilayers. This uniaxial diffusion was proved before by {sup 2}H, {sup 15}N and {sup 13}C NMR lineshapes of M2TMP in DLPC bilayers. When bound to an inhibitor, amantadine, the protein exhibits significantly narrower linewidths at physiological temperature. We now investigate the origin of this line narrowing through temperature-dependent {sup 1}H T{sub 1{rho}} relaxation times in the absence and presence of amantadine. Analysis of the temperature dependence indicates that amantadine decreases the correlation time of motion from 2.8 {+-} 0.9 {mu}s for the apo peptide to 0.89 {+-} 0.41 {mu}s for the bound peptide at 313 K. Thus the line narrowing of the bound peptide is due to better avoidance of the NMR time scale and suppression of intermediate time scale broadening. The faster diffusion of the bound peptide is due to the higher attempt rate of motion, suggesting that amantadine creates better-packed and more cohesive helical bundles. Analysis of the temperature dependence of ln (T{sub 1{rho}}{sup -1}) indicates that the activation energy of motion increased from 14.0 {+-} 4.0 kJ/mol for the apo peptide to 23.3 {+-} 6.2 kJ/mol for the bound peptide. This higher activation energy indicates that excess amantadine outside the protein channel in the lipid bilayer increases the membrane viscosity. Thus, the protein-bound amantadine speeds up the diffusion of the helical bundles while the excess amantadine in the bilayer increases the membrane viscosity.

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

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.

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.

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...

Bounded Densities and Their Derivatives

DEFF Research Database (Denmark)

Kozine, Igor; Krymsky, V.

2009-01-01

This paper describes how one can compute interval-valued statistical measures given limited information about the underlying distribution. The particular focus is on a bounded derivative of a probability density function and its combination with other available statistical evidence for computing ...... quantities of interest. To be able to utilise the evidence about the derivative it is suggested to adapt the ‘conventional’ problem statement to variational calculus and the way to do so is demonstrated. A number of examples are given throughout the paper....

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

Anticancer activities of bovine and human lactoferricin-derived peptides

NARCIS (Netherlands)

Arias, M.; Hilchie, A.L.; Haney, E.F.; Bolscher, J.G.M.; Hyndman, M.E.; Hancock, R.E.W.; Vogel, H.J.

2017-01-01

Lactoferrin (LF) is a mammalian host defense glycoprotein with diverse biological activities. Peptides derived from the cationic region of LF possess cytotoxic activity against cancer cells in vitro and in vivo. Bovine lactoferricin (LFcinB), a peptide derived from bovine LF (bLF), exhibits

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

Directory of Open Access Journals (Sweden)

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

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

Structure, Content, and Bioactivity of Food-Derived Peptides in the Body.

Science.gov (United States)

Sato, Kenji

2018-03-28

Orally administered peptides are assumed to be degraded into amino acids in the body. However, our recent studies revealed some food-derived prolyl and pyroglutamyl peptides with 2-3 amino acid residues in the blood of humans and animals, while most of the peptides in the endoproteinase digest of food protein are degraded by exopeptidase. Some food-derived dipeptides in the body display in vitro and in vivo biological activities. These facts indicate that the biological activities of food-derived peptides in the body rather than those in food are crucial to understanding the mechanism of the beneficial effects of orally administered peptides.

Food Derived Bioactive Peptides and Intestinal Barrier Function

Directory of Open Access Journals (Sweden)

Olga Martínez-Augustin

2014-12-01

Full Text Available A wide range of food-derived bioactive peptides have been shown to exert health-promoting actions and are therefore considered functional foods or nutraceuticals. Some of these actions are related to the maintenance, reinforcement or repairment of the intestinal barrier function (IBF whose role is to selectively allow the absorption of water, nutrients and ions while preventing the influx of microorganisms from the intestinal lumen. Alterations in the IBF have been related to many disorders, such as inflammatory bowel disease or metabolic syndrome. Components of IBF are the intestinal epithelium, the mucus layer, secretory immunoglobulin A and cells of the innate and adaptive immune systems. Here we review the effects of food derived bioactive peptides on these IBF components. In vitro and in vivo effects, both in healthy and disease states, have been reviewed. Although limited, the available information indicates a potential for food-derived peptides to modify IBF and to contribute to disease treatment, but further research is needed to better isolate responsible peptides, and to help define their mode of action.

Lactoferricin B-derived peptides with inhibitory effects on ECE-dependent vasoconstriction.

Science.gov (United States)

Fernández-Musoles, Ricardo; López-Díez, José Javier; Torregrosa, Germán; Vallés, Salvador; Alborch, Enrique; Manzanares, Paloma; Salom, Juan B

2010-10-01

Endothelin-converting enzyme (ECE), a key peptidase in the endothelin (ET) system, cleaves inactive big ET-1 to produce active ET-1, which binds to ET(A) receptors to exert its vasoconstrictor and pressor effects. ECE inhibition could be beneficial in the treatment of hypertension. In this study, a set of eight lactoferricin B (LfcinB)-derived peptides, previously characterized in our laboratory as angiotensin-converting enzyme (ACE) inhibitory peptides, was examined for their inhibitory effects on ECE. In vitro inhibitory effects on ECE activity were assessed using both the synthetic fluorogenic peptide substrate V (FPS V) and the natural substrate big ET-1. To study vasoactive effects, an ex vivo functional assay was developed using isolated rabbit carotid artery segments. With FPS V, only four LfcinB-derived peptides induced inhibition of ECE activity, whereas the eight peptides showed ECE inhibitory effects with big ET-1 as substrate. Regarding the ex vivo assays, six LfcinB-derived peptides showed inhibition of big ET-1-induced, ECE-dependent vasoconstriction. A positive correlation between the inhibitory effects of LfcinB-derived peptides on ECE activity when using big ET-1 and the inhibitory effects on ECE-dependent vasoconstriction was shown. ECE-independent vasoconstriction induced by ET-1 was not affected, thus discarding effects of LfcinB-derived peptides on ET(A) receptors or intracellular signal transduction mechanisms. In conclusion, a combined in vitro and ex vivo method to assess the effects of potentially antihypertensive peptides on the ET system has been developed and applied to show the inhibitory effects on ECE-dependent vasoconstriction of six LfcinB-derived peptides, five of which were dual vasopeptidase (ACE/ECE) inhibitors. Copyright © 2010 Elsevier Inc. All rights reserved.

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

A microbially derived tyrosine-sulfated peptide mimics a plant peptide hormone.

Science.gov (United States)

Pruitt, Rory N; Joe, Anna; Zhang, Weiguo; Feng, Wei; Stewart, Valley; Schwessinger, Benjamin; Dinneny, José R; Ronald, Pamela C

2017-07-01

The biotrophic pathogen Xanthomonas oryzae pv. oryzae (Xoo) produces a sulfated peptide named RaxX, which shares similarity to peptides in the PSY (plant peptide containing sulfated tyrosine) family. We hypothesize that RaxX mimics the growth-stimulating activity of PSY peptides. Root length was measured in Arabidopsis and rice treated with synthetic RaxX peptides. We also used comparative genomic analyses and reactive oxygen species burst assays to evaluate the activity of RaxX and PSY peptides. Here we found that a synthetic sulfated RaxX derivative comprising 13 residues (RaxX13-sY), highly conserved between RaxX and PSY, induces root growth in Arabidopsis and rice in a manner similar to that triggered by PSY. We identified residues that are required for activation of immunity mediated by the rice XA21 receptor but that are not essential for root growth induced by PSY. Finally, we showed that a Xanthomonas strain lacking raxX is impaired in virulence. These findings suggest that RaxX serves as a molecular mimic of PSY peptides to facilitate Xoo infection and that XA21 has evolved the ability to recognize and respond specifically to the microbial form of the peptide. © 2017 UT-Battelle LLC. New Phytologist © 2017 New Phytologist Trust.

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

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.

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.

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.

The pharmacokinetics and pharmacodynamics of progastrin-derived peptides

DEFF Research Database (Denmark)

Hansen, Carsten Palnaes

2003-01-01

The elimination of progastrin-derived peptides was a first-order process, also at supraphysiological concentrations in plasma. The site of extraction was dependent on the molecular size of the peptides and not on their bioactivity. Apart from the kidneys and brain, where the extraction...

Antimicrobial and immunomodulatory activities of PR-39 derived peptides.

Directory of Open Access Journals (Sweden)

Edwin J A Veldhuizen

Full Text Available The porcine cathelicidin PR-39 is a host defence peptide that plays a pivotal role in the innate immune defence of the pig against infections. Besides direct antimicrobial activity, it is involved in immunomodulation, wound healing and several other biological processes. In this study, the antimicrobial- and immunomodulatory activity of PR-39, and N- and C-terminal derivatives of PR-39 were tested. PR-39 exhibited an unexpected broad antimicrobial spectrum including several Gram positive strains such as Bacillus globigii and Enterococcus faecalis. Of organisms tested, only Staphylococcus aureus was insensitive to PR-39. Truncation of PR-39 down to 15 (N-terminal amino acids did not lead to major loss of activity, while peptides corresponding to the C-terminal part of PR-39 were hampered in their antimicrobial activity. However, shorter peptides were all much more sensitive to inhibition by salt. Active peptides induced ATP leakage and loss of membrane potential in Bacillus globigii and Escherichia coli, indicating a lytic mechanism of action for these peptides. Finally, only the mature peptide was able to induce IL-8 production in porcine macrophages, but some shorter peptides also had an effect on TNF-α production showing differential regulation of cytokine induction by PR-39 derived peptides. None of the active peptides showed high cytotoxicity highlighting the potential of these peptides for use as an alternative to antibiotics.

Antimicrobial and Immunomodulatory Activities of PR-39 Derived Peptides

Science.gov (United States)

Veldhuizen, Edwin J. A.; Schneider, Viktoria A. F.; Agustiandari, Herfita; van Dijk, Albert; Tjeerdsma-van Bokhoven, Johanna L. M.; Bikker, Floris J.; Haagsman, Henk P.

2014-01-01

The porcine cathelicidin PR-39 is a host defence peptide that plays a pivotal role in the innate immune defence of the pig against infections. Besides direct antimicrobial activity, it is involved in immunomodulation, wound healing and several other biological processes. In this study, the antimicrobial- and immunomodulatory activity of PR-39, and N- and C-terminal derivatives of PR-39 were tested. PR-39 exhibited an unexpected broad antimicrobial spectrum including several Gram positive strains such as Bacillus globigii and Enterococcus faecalis. Of organisms tested, only Staphylococcus aureus was insensitive to PR-39. Truncation of PR-39 down to 15 (N-terminal) amino acids did not lead to major loss of activity, while peptides corresponding to the C-terminal part of PR-39 were hampered in their antimicrobial activity. However, shorter peptides were all much more sensitive to inhibition by salt. Active peptides induced ATP leakage and loss of membrane potential in Bacillus globigii and Escherichia coli, indicating a lytic mechanism of action for these peptides. Finally, only the mature peptide was able to induce IL-8 production in porcine macrophages, but some shorter peptides also had an effect on TNF-α production showing differential regulation of cytokine induction by PR-39 derived peptides. None of the active peptides showed high cytotoxicity highlighting the potential of these peptides for use as an alternative to antibiotics. PMID:24755622

Vulnerable Derivatives and Good Deal Bounds: A Structural Model

DEFF Research Database (Denmark)

Murgoci, Agatha

2013-01-01

We price vulnerable derivatives -- i.e. derivatives where the counterparty may default. These are basically the derivatives traded on the over-the-counter (OTC) markets. Default is modeled in a structural framework. The technique employed for pricing is good deal bounds (GDBs). The method imposes...

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.

Two-dimensional sum-frequency generation (2D SFG) reveals structure and dynamics of a surface-bound peptide

Science.gov (United States)

Laaser, Jennifer E.; Skoff, David R.; Ho, Jia-Jung; Joo, Yongho; Serrano, Arnaldo L.; Steinkruger, Jay D.; Gopalan, Padma; Gellman, Samuel H.; Zanni, Martin T.

2014-01-01

Surface-bound polypeptides and proteins are increasingly used to functionalize inorganic interfaces such as electrodes, but their structural characterization is exceedingly difficult with standard technologies. In this paper, we report the first two-dimensional sum-frequency generation (2D SFG) spectra of a peptide monolayer, which is collected by adding a mid-IR pulse shaper to a standard femtosecond SFG spectrometer. On a gold surface, standard FTIR spectroscopy is inconclusive about the peptide structure because of solvation-induced frequency shifts, but the 2D lineshapes, anharmonic shifts, and lifetimes obtained from 2D SFG reveal that the peptide is largely α-helical and upright. Random coil residues are also observed, which do not themselves appear in SFG spectra due to their isotropic structural distribution, but which still absorb infrared light and so can be detected by cross-peaks in 2D SFG spectra. We discuss these results in the context of peptide design. Because of the similar way in which the spectra are collected, these 2D SFG spectra can be directly compared to 2D IR spectra, thereby enabling structural interpretations of surface-bound peptides and biomolecules based on the well-studied structure/2D IR spectra relationships established from soluble proteins. PMID:24372101

Bioactive Properties of Maillard Reaction Products Generated From Food Protein-derived Peptides.

Science.gov (United States)

Arihara, K; Zhou, L; Ohata, M

Food protein-derived peptides are promising food ingredients for developing functional foods, since various bioactive peptides are released from food proteins. The Maillard reaction, which plays an important role in most processed foods, generates various chemical components during processing. Although changes of amino acids or proteins and reduced sugars by the Maillard reaction have been studied extensively, such changes of peptides by the Maillard reaction are still not resolved enough. Since food protein-derived peptides are widely utilized in many processed foods, it deserves concern and research on the changes of peptides by the Maillard reaction in foods during processing or storage. This chapter initially overviewed food protein-derived bioactive peptides. Then, Maillard reaction products generated from peptides are discussed. We focused particularly on their bioactivities. © 2017 Elsevier Inc. All rights reserved.

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.

Immunomodulatory and Anti-Inflammatory Activities of Chicken Cathelicidin-2 Derived Peptides

Science.gov (United States)

van Dijk, Albert; van Eldik, Mandy; Veldhuizen, Edwin J. A.; Tjeerdsma-van Bokhoven, Hanne L. M.; de Zoete, Marcel R.; Bikker, Floris J.; Haagsman, Henk P.

2016-01-01

Host Defence Peptides and derived peptides are promising classes of antimicrobial and immunomodulatory lead compounds. For this purpose we examined whether chicken cathelicidin-2 (CATH-2)-derived peptides modulate the function and inflammatory response of avian immune cells. Using a chicken macrophage cell line (HD11) we found that full-length CATH-2 dose-dependently induced transcription of chemokines CXCLi2/IL-8, MCP-3 and CCLi4/RANTES, but not of pro-inflammatory cytokine IL-1β. In addition, CATH-2 efficiently inhibited IL-1β and nitric oxide production by HD11 cells induced by different sources of lipopolysaccharides (LPS). N-terminal truncated CATH-2 derived peptides maintained the capacity to selectively induce chemokine transcription, but despite their high LPS affinity several analogs lacked LPS-neutralizing capacity. Substitution of phenylalanine residues by tryptophan introduced endotoxin neutralization capacity in inactive truncated CATH-2 derived peptides. In contrast, amino acid substitution of phenylalanine by tyrosine abrogated endotoxin neutralization activity of CATH-2 analogs. These findings support a pivotal role for aromatic residues in peptide-mediated endotoxin neutralization by CATH-2 analogs and were shown to be independent of LPS affinity. The capacity to modulate chemokine production and dampen endotoxin-induced pro-inflammatory responses in chicken immune cells implicates that small CATH-2 based peptides could serve as leads for the design of CATH-2 based immunomodulatory anti-infectives. PMID:26848845

Immunomodulatory and Anti-Inflammatory Activities of Chicken Cathelicidin-2 Derived Peptides.

Directory of Open Access Journals (Sweden)

Albert van Dijk

Full Text Available Host Defence Peptides and derived peptides are promising classes of antimicrobial and immunomodulatory lead compounds. For this purpose we examined whether chicken cathelicidin-2 (CATH-2-derived peptides modulate the function and inflammatory response of avian immune cells. Using a chicken macrophage cell line (HD11 we found that full-length CATH-2 dose-dependently induced transcription of chemokines CXCLi2/IL-8, MCP-3 and CCLi4/RANTES, but not of pro-inflammatory cytokine IL-1β. In addition, CATH-2 efficiently inhibited IL-1β and nitric oxide production by HD11 cells induced by different sources of lipopolysaccharides (LPS. N-terminal truncated CATH-2 derived peptides maintained the capacity to selectively induce chemokine transcription, but despite their high LPS affinity several analogs lacked LPS-neutralizing capacity. Substitution of phenylalanine residues by tryptophan introduced endotoxin neutralization capacity in inactive truncated CATH-2 derived peptides. In contrast, amino acid substitution of phenylalanine by tyrosine abrogated endotoxin neutralization activity of CATH-2 analogs. These findings support a pivotal role for aromatic residues in peptide-mediated endotoxin neutralization by CATH-2 analogs and were shown to be independent of LPS affinity. The capacity to modulate chemokine production and dampen endotoxin-induced pro-inflammatory responses in chicken immune cells implicates that small CATH-2 based peptides could serve as leads for the design of CATH-2 based immunomodulatory anti-infectives.

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.

Photoperiod Regulates vgf-Derived Peptide Processing in Siberian Hamsters.

Directory of Open Access Journals (Sweden)

Barbara Noli

Full Text Available VGF mRNA is induced in specific hypothalamic areas of the Siberian hamster upon exposure to short photoperiods, which is associated with a seasonal decrease in appetite and weight loss. Processing of VGF generates multiple bioactive peptides, so the objective of this study was to determine the profile of the VGF-derived peptides in the brain, pituitary and plasma from Siberian hamsters, and to establish whether differential processing might occur in the short day lean state versus long day fat. Antisera against short sequences at the C- or N- termini of proVGF, as well as against NERP-1, TPGH and TLQP peptides, were used for analyses of tissues, and both immunohistochemistry and enzyme linked immunosorbent assay (ELISA coupled with high-performance liquid (HPLC or gel chromatography were carried out. VGF peptide immunoreactivity was found within cortex cholinergic perikarya, in multiple hypothalamic nuclei, including those containing vasopressin, and in pituitary gonadotrophs. ELISA revealed that exposure to short day photoperiod led to a down-regulation of VGF immunoreactivity in the cortex, and a less pronounced decrease in the hypothalamus and pituitary, while the plasma VGF levels were not affected by the photoperiod. HPLC and gel chromatography both confirmed the presence of multiple VGF-derived peptides in these tissues, while gel chromatography showed the presence of the VGF precursor in all tissues tested except for the cortex. These observations are consistent with the view that VGF-derived peptides have pleiotropic actions related to changing photoperiod, possibly by regulating cholinergic systems in the cortex, vasopressin hypothalamic pathways, and the reproductive axis.

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.

Food-derived bioactive peptides on inflammation and oxidative stress.

Science.gov (United States)

Chakrabarti, Subhadeep; Jahandideh, Forough; Wu, Jianping

2014-01-01

Chronic diseases such as atherosclerosis and cancer are now the leading causes of morbidity and mortality worldwide. Inflammatory processes and oxidative stress underlie the pathogenesis of these pathological conditions. Bioactive peptides derived from food proteins have been evaluated for various beneficial effects, including anti-inflammatory and antioxidant properties. In this review, we summarize the roles of various food-derived bioactive peptides in inflammation and oxidative stress and discuss the potential benefits and limitations of using these compounds against the burden of chronic diseases.

Dimerization effects on coacervation property of an elastin-derived synthetic peptide (FPGVG)5.

Science.gov (United States)

Suyama, Keitaro; Taniguchi, Suguru; Tatsubo, Daiki; Maeda, Iori; Nose, Takeru

2016-04-01

Elastin, a core protein of the elastic fibers, exhibits the coacervation (temperature-dependent reversible association/dissociation) under physiological conditions. Because of this characteristic, elastin and elastin-derived peptides have been considered to be useful as base materials for developing various biomedical products, skin substitutes, synthetic vascular grafts, and drug delivery systems. Although elastin-derived polypeptide (Val-Pro-Gly-Val-Gly)n also has been known to demonstrate coacervation property, a sufficiently high (VPGVG)n repetition number (n>40) is required for coacervation. In the present study, a series of elastin-derived peptide (Phe-Pro-Gly-Val-Gly)5 dimers possessing high coacervation potential were newly developed. These novel dimeric peptides exhibited coacervation at significantly lower concentrations and temperatures than the commonly used elastin-derived peptide analogs; this result suggests that the coacervation ability of the peptides is enhanced by dimerization. Circular dichroism (CD) measurements indicate that the dimers undergo similar temperature-dependent and reversible conformational changes when coacervation occurs. The molecular dynamics calculation results reveal that the sheet-turn-sheet motif involving a type II β-turn-like structure commonly observed among the dimers and caused formation of globular conformation of them. These synthesized peptide dimers may be useful not only as model peptides for structural analysis of elastin and elastin-derived peptides, but also as base materials for developing various temperature-sensitive biomedical and industrial products. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

Identification of MHC class I H-2 Kb/Db-restricted immunogenic peptides derived from retinal proteins

DEFF Research Database (Denmark)

Wang, Mingjun; Bai, Fang; Pries, Mette

2006-01-01

PURPOSE: To identify H-2 Kb/Db-binding immunogenic peptides derived from retinal proteins. METHODS: Computer-based prediction was used to identify potentially H-2 Kb/Db-binding peptides derived from the interphotoreceptor retinol-binding protein (IRBP), soluble retinal antigen (S...... on day 21 after immunization with IRBP or IRBP and the immunogenic peptides. RESULTS: All the 21 predicted peptides were found to upregulate expression of H-2 Kb/Db on RMA-S cells. Five peptides, the two IRBP-derived peptides IRBP89-96 and IRBP(101-108), and the three PEDF-derived peptides, PEDF389....... The immunogenic peptides alone did not induce inflammation in the eyes, but they could enhance severity of uveitis induced by IRBP. CONCLUSIONS: Five of 21 H-2 Kb/Db-binding retinal protein-derived peptides were found to be immunogenic, suggesting that these peptides could function as autoantigenic epitopes...

Multimerized CHR-derived peptides as HIV-1 fusion inhibitors.

Science.gov (United States)

Nomura, Wataru; Hashimoto, Chie; Suzuki, Takaharu; Ohashi, Nami; Fujino, Masayuki; Murakami, Tsutomu; Yamamoto, Naoki; Tamamura, Hirokazu

2013-08-01

To date, several HIV-1 fusion inhibitors based on the carboxy-terminal leucine/isoleucine heptad repeat (CHR) region of an HIV-1 envelope protein gp41 have been discovered. We have shown that a synthetic peptide mimetic of a trimer form of the CHR-derived peptide C34 has potent inhibitory activity against the HIV-1 fusion mechanism, compared to a monomer C34 peptide. The present study revealed that a dimeric form of C34 is evidently structurally critical for fusion inhibitors, and that the activity of multimerized CHR-derived peptides in fusion inhibition is affected by the properties of the unit peptides C34, SC34EK, and T20. The fluorescence-based study suggested that the N36-interactive sites of the C34 trimer, including hydrophobic residues, are exposed outside the trimer and that trimerization of C34 caused a remarkable increase in fusion inhibitory activity. The present results could be useful in the design of fusion inhibitors against viral infections which proceed via membrane fusion with host cells. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

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.

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 ...

BioPepDB: an integrated data platform for food-derived bioactive peptides.

Science.gov (United States)

Li, Qilin; Zhang, Chao; Chen, Hongjun; Xue, Jitong; Guo, Xiaolei; Liang, Ming; Chen, Ming

2018-03-12

Food-derived bioactive peptides play critical roles in regulating most biological processes and have considerable biological, medical and industrial importance. However, a large number of active peptides data, including sequence, function, source, commercial product information, references and other information are poorly integrated. BioPepDB is a searchable database of food-derived bioactive peptides and their related articles, including more than four thousand bioactive peptide entries. Moreover, BioPepDB provides modules of prediction and hydrolysis-simulation for discovering novel peptides. It can serve as a reference database to investigate the function of different bioactive peptides. BioPepDB is available at http://bis.zju.edu.cn/biopepdbr/ . The web page utilises Apache, PHP5 and MySQL to provide the user interface for accessing the database and predict novel peptides. The database itself is operated on a specialised server.

Glycotriazole-peptides derived from the peptide HSP1: synergistic effect of triazole and saccharide rings on the antifungal activity.

Science.gov (United States)

Junior, Eduardo F C; Guimarães, Carlos F R C; Franco, Lucas L; Alves, Ricardo J; Kato, Kelly C; Martins, Helen R; de Souza Filho, José D; Bemquerer, Marcelo P; Munhoz, Victor H O; Resende, Jarbas M; Verly, Rodrigo M

2017-08-01

This work proposes a strategy that uses solid-phase peptide synthesis associated with copper(I)-catalyzed azide alkyne cycloaddition reaction to promote the glycosylation of an antimicrobial peptide (HSP1) containing a carboxyamidated C-terminus (HSP1-NH 2 ). Two glycotriazole-peptides, namely [p-Glc-trz-G 1 ]HSP1-NH 2 and [p-GlcNAc-trz-G 1 ]HSP1-NH 2 , were prepared using per-O-acetylated azide derivatives of glucose and N-acetylglucosamine in the presence of copper(II) sulfate pentahydrate (CuSO 4 ·5H 2 O) and sodium ascorbate as a reducing agent. In order to investigate the synergistic action of the carbohydrate motif linked to the triazole-peptide structure, a triazole derivative [trz-G 1 ]HSP1-NH 2 was also prepared. A set of biophysical approaches such as DLS, Zeta Potential, SPR and carboxyfluorescein leakage from phospholipid vesicles confirmed higher membrane disruption and lytic activities as well as stronger peptide-LUVs interactions for the glycotriazole-peptides when compared to HSP1-NH 2 and to its triazole derivative, which is in accordance with the performed biological assays: whereas HSP1-NH 2 presents relatively low and [trz-G 1 ]HSP1-NH 2 just moderate fungicidal activity, the glycotriazole-peptides are significantly more effective antifungal agents. In addition, the glycotriazole-peptides and the triazole derivative present strong inhibition effects on ergosterol biosynthesis in Candida albicans, when compared to HSP1-NH 2 alone. In conclusion, the increased fungicidal activity of the glycotriazole-peptides seems to be the result of (A) more pronounced membrane-disruptive properties, which is related to the presence of a saccharide ring, together with (B) the inhibition of ergosterol biosynthesis, which seems to be related to the presence of both the monosaccharide and the triazole rings.

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...

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.

Biophysical analysis of the interaction of granulysin-derived peptides with enterobacterial endotoxins.

Science.gov (United States)

Chen, Xi; Howe, Jörg; Andrä, Jörg; Rössle, Manfred; Richter, Walter; da Silva, Ana Paula Galvão; Krensky, Alan M; Clayberger, Carol; Brandenburg, Klaus

2007-10-01

To combat infections by Gram-negative bacteria, it is not only necessary to kill the bacteria but also to neutralize pathogenicity factors such as endotoxin (lipopolysaccharide, LPS). The development of antimicrobial peptides based on mammalian endotoxin-binding proteins is a promising tool in the fight against bacterial infections, and septic shock syndrome. Here, synthetic peptides derived from granulysin (Gra-pep) were investigated in microbiological and biophysical assays to understand their interaction with LPS. We analyzed the influence of the binding of Gra-pep on (1) the acyl chain melting of the hydrophobic moiety of LPS, lipid A, by Fourier-transform spectroscopy, (2) the aggregate structure of LPS by small-angle X-ray scattering and cryo-transmission electron microscopy, and 3) the enthalpy change by isothermal titration calorimetry. In addition, the influence of Gra-pep on the incorporation of LPS and LPS-LBP (lipopolysaccharide-binding protein) complexes into negatively charged liposomes was monitored. Our findings demonstrate a characteristic change in the aggregate structure of LPS into multilamellar stacks in the presence of Gra-pep, but little or no change of acyl chain fluidity. Neutralization of LPS by Gra-pep is not due to a scavenging effect in solution, but rather proceeds after incorporation into target membranes, suggesting a requisite membrane-bound step.

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

Energy Technology Data Exchange (ETDEWEB)

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.

Structure of Calmodulin Bound to a Calcineurin Peptide: A New Way of Making an Old Binding Mode

International Nuclear Information System (INIS)

Ye, Q.; Li, X.; Wong, A.; Wei, Q.; Jia, Z.

2006-01-01

Calcineurin is a calmodulin-binding protein in brain and the only serine/threonine protein phosphatase under the control of Ca 2+ /calmodulin (CaM), which plays a critical role in coupling Ca 2+ signals to cellular responses. CaM up-regulates the phosphatase activity of calcineurin by binding to the CaM-binding domain (CBD) of calcineurin subunit A. Here, we report crystal structural studies of CaM bound to a CBD peptide. The chimeric protein containing CaM and the CBD peptide forms an intimate homodimer, in which CaM displays a native-like extended conformation and the CBD peptide shows -helical structure. Unexpectedly, the N-terminal lobe from one CaM and the C-terminal lobe from the second molecule form a combined binding site to trap the peptide. Thus, the dimer provides two binding sites, each of which is reminiscent of the fully collapsed conformation of CaM commonly observed in complex with, for example, the myosin light chain kinase (MLCK) peptide. The interaction between the peptide and CaM is highly specific and similar to MLCK

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.

Marine-Derived Bioactive Peptides with Pharmacological Activities- A Review

Directory of Open Access Journals (Sweden)

Sana Rabiei

2017-10-01

Full Text Available Some nutritional factors are related to chronic disease. In response to increased concern regarding nutrition and health, the functional and nutraceuticals food markets have been developed. During food digestion, proteins are hydrolyzed and a wide range of peptides are formed. Some of these peptides have special structures which permit them to confer particular biological functions. Marine animals which involve more than half of the world biological varieties are a wide source of bioactive proteins and peptides. Marine derived peptides show various physiologic functions such as anti-oxidant, antimicrobial, anti-cancer, Angiotensin1-Converting Enzyme (ACE glucosidase and a-amylase inhibitory effects in vitro. Before application of marine bioactive peptides as nutraceuticals or functional food ingredients, their efficacy should be approved through pre-clinical animal and then clinical studies. The aim of this study was to review the studies conducted on the pharmacological effect of marine bioactive peptides in animal models and humans.

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

Milk derived bioactive peptides and their impact on human health – A review

Directory of Open Access Journals (Sweden)

D.P. Mohanty

2016-09-01

Full Text Available Milk-derived bioactive peptides have been identified as potential ingredients of health-promoting functional foods. These bioactive peptides are targeted at diet-related chronic diseases especially the non-communicable diseases viz., obesity, cardiovascular diseases and diabetes. Peptides derived from the milk of cow, goat, sheep, buffalo and camel exert multifunctional properties, including anti-microbial, immune modulatory, anti-oxidant, inhibitory effect on enzymes, anti-thrombotic, and antagonistic activities against various toxic agents. Majority of those regulate immunological, gastrointestinal, hormonal and neurological responses, thereby playing a vital role in the prevention of cancer, osteoporosis, hypertension and other disorders as discussed in this review. For the commercial production of such novel bioactive peptides large scale technologies based on membrane separation and ion exchange chromatography methods have been developed. Separation and identification of those peptides and their pharmacodynamic parameters are necessary to transfer their potent functional properties into food applications. The present review summarizes the preliminary classes of bioactive milk-derived peptides along with their physiological functions, general characteristics and potential applications in health-care.

Novel angiotensin-converting enzyme (ACE) inhibitory peptides derived from boneless chicken leg meat.

Science.gov (United States)

Terashima, Masaaki; Baba, Takako; Ikemoto, Narumi; Katayama, Midori; Morimoto, Tomoko; Matsumura, Saki

2010-06-23

Four peptides that inhibit angiotensin-converting enzyme (ACE) were separated from the hydorlysate of boneless chicken leg meat digested with artificial gastric juice (pepsin). Two peptides were identified as the peptides encrypted in myosin heavy chain. The peptide P1 (MNVKHWPWMK) corresponds to the amino acid sequence from amino acids 825 to 834 of myosin heavy chain, and the peptide P4 (VTVNPYKWLP) corresponds to the amino acid sequence from amino acids 125 to 135 of myosin heavy chain. They are novel ACE inhibitory peptides derived from chicken, and IC(50) values of P1 and P4 were determined as 228 and 5.5 microM, respectively. Although these values were much larger than 0.022 microM for captopril, a typical synthetic ACE inhibitor, they are comparable to IC(50) values reported for various ACE inhibitory peptides derived from foods. Because the peptide P4 has a relatively low IC(50) value, it is a good starting substance for designing food supplements for hypertensive patients.

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.

Peptides derived from the solvent-exposed loops 3 and 4 of BDNF bind TrkB and p75(NTR) receptors and stimulate neurite outgrowth and survival

DEFF Research Database (Denmark)

Fobian, Kristina; Owczarek, Sylwia; Budtz, Christian

2010-01-01

Brain-derived neurotrophic factor (BDNF) is critically involved in modeling the developing nervous system and is an important regulator of a variety of crucial functions in the mature CNS. BDNF exerts its action through interactions with two transmembrane receptors, either separately or in concert....... BDNF has been implicated in several neurological disorders, and irregularities in BDNF function may have severe consequences. Administration of BDNF as a drug has thus far yielded few practicable results, and the potential side effects when using a multifunctional protein are substantial. In an effort...... to produce more specific compounds without side effects, small peptides mimicking protein function have been developed. The present study characterized two mimetic peptides, Betrofin 3 and Betrofin 4, derived from the BDNF sequence. Both Betrofins bound the cognate BDNF receptors, TrkB and p75(NTR...

Immunogenicity of HLA Class I and II Double Restricted Influenza A-Derived Peptides

DEFF Research Database (Denmark)

Pedersen, Sara Ram; Christensen, Jan Pravsgaard; Buus, Søren

2016-01-01

The aim of the present study was to identify influenza A-derived peptides which bind to both HLA class I and -II molecules and by immunization lead to both HLA class I and class II restricted immune responses. Eight influenza A-derived 9-11mer peptides with simultaneous binding to both HLA-A*02...... four of the double binding peptides did result in HLA-A*02:01 restricted responses only. According to their cytokine profile, the CD4 T cell responses were of the Th2 type. In influenza infected mice, we were unable to detect natural processing in vivo of the double restricted peptides and in line...... with this, peptide vaccination did not decrease virus titres in the lungs of intranasally influenza challenged mice. Our data show that HLA class I and class II double binding peptides can be identified by bioinformatics and biochemical technology. By immunization, double binding peptides can give rise...

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.

Antimicrobial properties of two novel peptides derived from Theobroma cacao osmotin.

Science.gov (United States)

Falcao, Loeni L; Silva-Werneck, Joseilde O; Ramos, Alessandra de R; Martins, Natalia F; Bresso, Emmanuel; Rodrigues, Magali A; Bemquerer, Marcelo P; Marcellino, Lucilia H

2016-05-01

The osmotin proteins of several plants display antifungal activity, which can play an important role in plant defense against diseases. Thus, this protein can be useful as a source for biotechnological strategies aiming to combat fungal diseases. In this work, we analyzed the antifungal activity of a cacao osmotin-like protein (TcOsm1) and of two osmotin-derived synthetic peptides with antimicrobial features, differing by five amino acids residues at the N-terminus. Antimicrobial tests showed that TcOsm1 expressed in Escherichia coli inhibits the growth of Moniliophthora perniciosa mycelium and Pichia pastoris X-33 in vitro. The TcOsm1-derived peptides, named Osm-pepA (H-RRLDRGGVWNLNVNPGTTGARVWARTK-NH2), located at R23-K49, and Osm-pepB (H-GGVWNLNVNPGTTGARVWARTK-NH2), located at G28-K49, inhibited growth of yeasts (Saccharomyces cerevisiae S288C and Pichia pastoris X-33) and spore germination of the phytopathogenic fungi Fusarium f. sp. glycines and Colletotrichum gossypi. Osm-pepA was more efficient than Osm-pepB for S. cerevisiae (MIC=40μM and MIC=127μM, respectively), as well as for P. pastoris (MIC=20μM and MIC=127μM, respectively). Furthermore, the peptides presented a biphasic performance, promoting S. cerevisiae growth in doses around 5μM and inhibiting it at higher doses. The structural model for these peptides showed that the five amino acids residues, RRLDR at Osm-pepA N-terminus, significantly affect the tertiary structure, indicating that this structure is important for the peptide antimicrobial potency. This is the first report of development of antimicrobial peptides from T. cacao. Taken together, the results indicate that the cacao osmotin and its derived peptides, herein studied, are good candidates for developing biotechnological tools aiming to control phytopathogenic fungi. Copyright © 2016 Elsevier Inc. All rights reserved.

Antimicrobial activity of bovine NK-lysin-derived peptides on Mycoplasma bovis

Science.gov (United States)

Antimicrobial peptides (AMPs) are a diverse group of molecules which play an important role in the innate immune response. Bovine NK-lysins, a type of AMP, have been predominantly found in the granules of cytotoxic T-lymphocytes and NK-cells. Bovine NK-lysin-derived peptides demonstrate antimicrobia...

Lactoferrin-derived Peptides Active towards Influenza: Identification of Three Potent Tetrapeptide Inhibitors.

Science.gov (United States)

Scala, Maria Carmina; Sala, Marina; Pietrantoni, Agostina; Spensiero, Antonia; Di Micco, Simone; Agamennone, Mariangela; Bertamino, Alessia; Novellino, Ettore; Bifulco, Giuseppe; Gomez-Monterrey, Isabel M; Superti, Fabiana; Campiglia, Pietro

2017-09-06

Bovine lactoferrin is a biglobular multifunctional iron binding glycoprotein that plays an important role in innate immunity against infections. We have previously demonstrated that selected peptides from bovine lactoferrin C-lobe are able to prevent both Influenza virus hemagglutination and cell infection. To deeper investigate the ability of lactoferrin derived peptides to inhibit Influenza virus infection, in this study we identified new bovine lactoferrin C-lobe derived sequences and corresponding synthetic peptides were synthesized and assayed to check their ability to prevent viral hemagglutination and infection. We identified three tetrapeptides endowed with broad anti-Influenza activity and able to inhibit viral infection in a concentration range femto- to picomolar. Our data indicate that these peptides may constitute a non-toxic tool for potential applications as anti-Influenza therapeutics.

Formation of taste-active amino acids, amino acid derivatives and peptides in food fermentations - A review.

Science.gov (United States)

Zhao, Cindy J; Schieber, Andreas; Gänzle, Michael G

2016-11-01

Fermented foods are valued for their rich and complex odour and taste. The metabolic activity of food-fermenting microorganisms determines food quality and generates odour and taste compounds. This communication reviews the formation of taste-active amino acids, amino acid derivatives and peptides in food fermentations. Pathways of the generation of taste compounds are presented for soy sauce, cheese, fermented meats, and bread. Proteolysis or autolysis during food fermentations generates taste-active amino acids and peptides; peptides derived from proteolysis particularly impart umami taste (e.g. α-glutamyl peptides) or bitter taste (e.g. hydrophobic peptides containing proline). Taste active peptide derivatives include pyroglutamyl peptides, γ-glutamyl peptides, and succinyl- or lactoyl amino acids. The influence of fermentation microbiota on proteolysis, and peptide hydrolysis, and the metabolism of glutamate and arginine is well understood, however, the understanding of microbial metabolic activities related to the formation of taste-active peptide derivatives is incomplete. Improved knowledge of the interactions between taste-active compounds will enable the development of novel fermentation strategies to develop tastier, less bitter, and low-salt food products, and may provide novel and "clean label" ingredients to improve the taste of other food products. Copyright © 2016 Elsevier Ltd. All rights reserved.

Identification of peptides from foot‐and‐mouth disease virus structural proteins bound by class I swine leukocyte antigen (SLA) alleles, SLA‐1*0401 and SLA‐2*0401

DEFF Research Database (Denmark)

Pedersen, Lasse Eggers; Harndahl, M.; Nielsen, Morten

2013-01-01

within the structural proteins of foot‐and‐mouth disease virus (FMDV), strain A24 were analyzed as candidate T‐cell epitopes. Peptides predicted by the NetMHCpan were tested in ELISA for binding to the SLA‐1*0401 and SLA‐2*0401 major histocompatibility complex class I proteins. Four of the 10 predicted...... FMDV peptides bound to SLA‐2*0401, whereas five of the nine predicted FMDV peptides bound to SLA‐1*0401. These methods provide the characterization of T‐cell epitopes in response to pathogens in more detail. The development of such approaches to analyze vaccine performance will contribute to a more...

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...

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...

Interaction of MreB-derived antimicrobial peptides with membranes.

Science.gov (United States)

Saikia, Karabi; Chaudhary, Nitin

2018-03-25

Antimicrobial peptides are critical components of defense systems in living forms. The activity is conferred largely by the selective membrane-permeabilizing ability. In our earlier work, we derived potent antimicrobial peptides from the 9-residue long, N-terminal amphipathic helix of E. coli MreB protein. The peptides display broad-spectrum activity, killing not only Gram-positive and Gram-negative bacteria but opportunistic fungus, Candida albicans as well. These results proved that membrane-binding stretches of bacterial proteins could turn out to be self-harming when applied from outside. Here, we studied the membrane-binding and membrane-perturbing potential of these peptides. Steady-state tryptophan fluorescence studies with tryptophan extended peptides, WMreB 1-9 and its N-terminal acetylated analog, Ac-WMreB 1-9 show preferential binding to negatively-charged liposomes. Both the peptides cause permeabilization of E. coli inner and outer-membranes. Tryptophan-lacking peptides, though permeabilize the outer-membrane efficiently, little permeabilization of the inner-membrane is observed. These data attest membrane-destabilization as the mechanism of rapid bacterial killing. This study is expected to motivate the research in identifying microbes' self-sequences to combat them. Copyright © 2018 Elsevier Inc. All rights reserved.

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.

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.

Identities of P2 and P3 Residues of H-2Kb-Bound Peptides Determine Mouse Ly49C Recognition.

Directory of Open Access Journals (Sweden)

Elsa A Marquez

Full Text Available Ly49 receptors can be peptide selective in their recognition of MHC-I-peptide complexes, affording them a level of discrimination beyond detecting the presence or absence of specific MHC-I allele products. Despite this ability, little is understood regarding the properties that enable some peptides, when bound to MHC-I molecules, to support Ly49 recognition, but not others. Using RMA-S target cells expressing MHC-I molecules loaded with individual peptides and effector cells expressing the ectodomain of the inhibitory Ly49C receptor, we found that two adjacent amino acid residues, P2 and P3, both buried in the peptide binding groove of H-2Kb, determine mouse Ly49C specificity. If both are aliphatic residues, this is supportive. Whereas, small amino acids at P2 and aromatic amino acids at the P3 auxiliary anchor residue are detrimental to Ly49C recognition. These results resemble those with a rat Ly49 where the identity of a peptide anchor residue determines recognition, suggesting that dependence on specific peptide residues buried in the MHC-I peptide-binding groove may be fundamental to Ly49 peptide selectivity and recognition.

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.

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.

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.

Antimicrobial Effects of Helix D-derived Peptides of Human Antithrombin III*

Science.gov (United States)

Papareddy, Praveen; Kalle, Martina; Bhongir, Ravi K. V.; Mörgelin, Matthias; Malmsten, Martin; Schmidtchen, Artur

2014-01-01

Antithrombin III (ATIII) is a key antiproteinase involved in blood coagulation. Previous investigations have shown that ATIII is degraded by Staphylococcus aureus V8 protease, leading to release of heparin binding fragments derived from its D helix. As heparin binding and antimicrobial activity of peptides frequently overlap, we here set out to explore possible antibacterial effects of intact and degraded ATIII. In contrast to intact ATIII, the results showed that extensive degradation of the molecule yielded fragments with antimicrobial activity. Correspondingly, the heparin-binding, helix d-derived, peptide FFFAKLNCRLYRKANKSSKLV (FFF21) of human ATIII, was found to be antimicrobial against particularly the Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa. Fluorescence microscopy and electron microscopy studies demonstrated that FFF21 binds to and permeabilizes bacterial membranes. Analogously, FFF21 was found to induce membrane leakage of model anionic liposomes. In vivo, FFF21 significantly reduced P. aeruginosa infection in mice. Additionally, FFF21 displayed anti-endotoxic effects in vitro. Taken together, our results suggest novel roles for ATIII-derived peptide fragments in host defense. PMID:25202017

Autologous peptides constitutively occupy the antigen binding site on Ia

DEFF Research Database (Denmark)

Buus, S; Sette, A; Colon, S M

1988-01-01

Low molecular weight material associated with affinity-purified class II major histocompatibility complex (MHC) molecules of mouse (Ia) had the expected properties of peptides bound to the antigen binding site of Ia. Thus, the low molecular weight material derived from the I-Ad isotype...

Seahorse-derived peptide suppresses invasive migration of HT1080 fibrosarcoma cells by competing with intracellular α-enolase for plasminogen binding and inhibiting uPA-mediated activation of plasminogen.

Science.gov (United States)

Kim, Yong-Tae; Kim, Se-kwon; Jeon, You-Jin; Park, Sun Joo

2014-12-01

α-Enolase is a glycolytic enzyme and a surface receptor for plasminogen. α-Enolase-bound plasminogen promotes tumor cell invasion and cancer metastasis by activating plasmin and consequently degrading the extracellular matrix degradation. Therefore, α-enolase and plasminogen are novel targets for cancer therapy. We found that the amino acid sequence of a peptide purified from enzymatic hydrolysates of seahorse has striking similarities to that of α-enolase. In this study, we report that this peptide competes with cellular α-enolase for plasminogen binding and suppresses urokinase plasminogen activator (uPA)-mediated activation of plasminogen, which results in decreased invasive migration of HT1080 fibrosarcoma cells. In addition, the peptide treatment decreased the expression levels of uPA compared to that of untreated controls. These results provide new insight into the mechanism by which the seahorse-derived peptide suppresses invasive properties of human cancer cells. Our findings suggest that this peptide could emerge as a potential therapeutic agent for cancer.

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.

Peptides derived from tryptic hydrolysate of Bacillus subtilis culture suppress fungal spoilage of table grapes.

Science.gov (United States)

Zhang, Bo; Wang, Jingnan; Ning, Shuqing; Yuan, Quan; Chen, Xiangning; Zhang, Yanyan; Fan, Junfeng

2018-01-15

This study confirmed the anti-fungal effect of trypsin-treated Bacillus subtilis culture (BC) (tryptic hydrolysate, TH) on mold growth on Kyoho grapes. We examined the anti-fungal activity of TH by identifying TH peptides and performing a computational docking analysis. TH was more potent than untreated BC in suppressing fungal growth on grapes. Specifically, TH maintained grape freshness by inhibiting respiration and rachis browning, maintaining firmness, and preventing weight loss. Thirty-six inhibitory peptides against β-1,3-glucan synthase (GS) were screened from 126 TH peptides identified through proteomic analysis. Among them, 13 peptides bound tightly to GS active pockets with lower binding energies than that of GppNHp. The most potent peptides, LFEIDEELNEK and FATSDLNDLYR, were synthesized, and further experiments showed that these peptides had a highly suppressive effect on GS activity and Aspergillus niger and Penicillium chrysogenum growth. Our results confirm that tryptic treatment is effective for improving the anti-fungal activity of BC. Copyright © 2017 Elsevier Ltd. All rights reserved.

Paramagnetic relaxation enhancements in NMR peptide-membrane interaction studies

International Nuclear Information System (INIS)

Kosol, S.

2011-01-01

Small membrane-bound proteins or peptides are involved in numerous essential biological processes, like cellular recognition, signaling, channel formation, and cytolysis. The secondary structure, orientation, mode of interaction and dynamics of these peptides can be as varied as their functions. Their localization in the membrane, the immersion depth, and their binding mode are factors critical to the function of these peptides. The atomic 3D solution structure of peptides bound to micelles can be determined by NMR spectroscopy. However, by employing paramagnetic relaxation enhancements (PREs) information on the complete topology of peptide bound to a micelle can be obtained. The antimicrobial peptide maximin H6, fst, a bacterial toxin, and the human peptide hormone ghrelin served as membrane-bound model peptides of similar sizes but strongly differing amino acid sequences. Their structures and binding behavior were determined and compared.The measured PREs provided suitable data for determining and distinguishing the different topologies of the investigated peptides bound to micelles. Maximin H6 and fst fold into α-helices upon insertion into a membrane, whereas the unstructured ghrelin is freely mobile in solution and interacts only via a covalently bound octanoyl group with the lipids. Maximin H6 is oriented parallel to the membrane surface, enabling the peptide to aggregate at the membrane water interface. Fst binds in transmembrane orientation with a protruding intrinsically disordered region near the C-terminus. Aside from determining the orientation of the bound peptides from the PREs, the moieties critical for membrane binding could be mapped in ghrelin. If suitable relaxation-edited spectra are acquired, the complete orientation and immersion depth of a peptide bound to a micelle can readily be obtained. (author) [de

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.

Focused Screening of ECM-Selective Adhesion Peptides on Cellulose-Bound Peptide Microarrays.

Science.gov (United States)

Kanie, Kei; Kondo, Yuto; Owaki, Junki; Ikeda, Yurika; Narita, Yuji; Kato, Ryuji; Honda, Hiroyuki

2016-11-19

The coating of surfaces with bio-functional proteins is a promising strategy for the creation of highly biocompatible medical implants. Bio-functional proteins from the extracellular matrix (ECM) provide effective surface functions for controlling cellular behavior. We have previously screened bio-functional tripeptides for feasibility of mass production with the aim of identifying those that are medically useful, such as cell-selective peptides. In this work, we focused on the screening of tripeptides that selectively accumulate collagen type IV (Col IV), an ECM protein that accelerates the re-endothelialization of medical implants. A SPOT peptide microarray was selected for screening owing to its unique cellulose membrane platform, which can mimic fibrous scaffolds used in regenerative medicine. However, since the library size on the SPOT microarray was limited, physicochemical clustering was used to provide broader variation than that of random peptide selection. Using the custom focused microarray of 500 selected peptides, we assayed the relative binding rates of tripeptides to Col IV, collagen type I (Col I), and albumin. We discovered a cluster of Col IV-selective adhesion peptides that exhibit bio-safety with endothelial cells. The results from this study can be used to improve the screening of regeneration-enhancing peptides.

Focused Screening of ECM-Selective Adhesion Peptides on Cellulose-Bound Peptide Microarrays

Directory of Open Access Journals (Sweden)

Kei Kanie

2016-11-01

Full Text Available The coating of surfaces with bio-functional proteins is a promising strategy for the creation of highly biocompatible medical implants. Bio-functional proteins from the extracellular matrix (ECM provide effective surface functions for controlling cellular behavior. We have previously screened bio-functional tripeptides for feasibility of mass production with the aim of identifying those that are medically useful, such as cell-selective peptides. In this work, we focused on the screening of tripeptides that selectively accumulate collagen type IV (Col IV, an ECM protein that accelerates the re-endothelialization of medical implants. A SPOT peptide microarray was selected for screening owing to its unique cellulose membrane platform, which can mimic fibrous scaffolds used in regenerative medicine. However, since the library size on the SPOT microarray was limited, physicochemical clustering was used to provide broader variation than that of random peptide selection. Using the custom focused microarray of 500 selected peptides, we assayed the relative binding rates of tripeptides to Col IV, collagen type I (Col I, and albumin. We discovered a cluster of Col IV-selective adhesion peptides that exhibit bio-safety with endothelial cells. The results from this study can be used to improve the screening of regeneration-enhancing peptides.

A Posteriori Finite Element Bounds for Sensitivity Derivatives of Partial-Differential-Equation Outputs. Revised

Science.gov (United States)

Lewis, Robert Michael; Patera, Anthony T.; Peraire, Jaume

1998-01-01

We present a Neumann-subproblem a posteriori finite element procedure for the efficient and accurate calculation of rigorous, 'constant-free' upper and lower bounds for sensitivity derivatives of functionals of the solutions of partial differential equations. The design motivation for sensitivity derivative error control is discussed; the a posteriori finite element procedure is described; the asymptotic bounding properties and computational complexity of the method are summarized; and illustrative numerical results are presented.

Antimicrobial effects of helix D-derived peptides of human antithrombin III.

Science.gov (United States)

Papareddy, Praveen; Kalle, Martina; Bhongir, Ravi K V; Mörgelin, Matthias; Malmsten, Martin; Schmidtchen, Artur

2014-10-24

Antithrombin III (ATIII) is a key antiproteinase involved in blood coagulation. Previous investigations have shown that ATIII is degraded by Staphylococcus aureus V8 protease, leading to release of heparin binding fragments derived from its D helix. As heparin binding and antimicrobial activity of peptides frequently overlap, we here set out to explore possible antibacterial effects of intact and degraded ATIII. In contrast to intact ATIII, the results showed that extensive degradation of the molecule yielded fragments with antimicrobial activity. Correspondingly, the heparin-binding, helix D-derived, peptide FFFAKLNCRLYRKANKSSKLV (FFF21) of human ATIII, was found to be antimicrobial against particularly the Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa. Fluorescence microscopy and electron microscopy studies demonstrated that FFF21 binds to and permeabilizes bacterial membranes. Analogously, FFF21 was found to induce membrane leakage of model anionic liposomes. In vivo, FFF21 significantly reduced P. aeruginosa infection in mice. Additionally, FFF21 displayed anti-endotoxic effects in vitro. Taken together, our results suggest novel roles for ATIII-derived peptide fragments in host defense. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Human lactoferricin derived di-peptides deploying loop structures induce apoptosis specifically in cancer cells through targeting membranous phosphatidylserine.

Science.gov (United States)

Riedl, Sabrina; Leber, Regina; Rinner, Beate; Schaider, Helmut; Lohner, Karl; Zweytick, Dagmar

2015-11-01

Host defense-derived peptides have emerged as a novel strategy for the development of alternative anticancer therapies. In this study we report on characteristic features of human lactoferricin (hLFcin) derivatives which facilitate specific killing of cancer cells of melanoma, glioblastoma and rhabdomyosarcoma compared with non-specific derivatives and the synthetic peptide RW-AH. Changes in amino acid sequence of hLFcin providing 9-11 amino acids stretched derivatives LF11-316, -318 and -322 only yielded low antitumor activity. However, the addition of the repeat (di-peptide) and the retro-repeat (di-retro-peptide) sequences highly improved cancer cell toxicity up to 100% at 20 μM peptide concentration. Compared to the complete parent sequence hLFcin the derivatives showed toxicity on the melanoma cell line A375 increased by 10-fold and on the glioblastoma cell line U-87mg by 2-3-fold. Reduced killing velocity, apoptotic blebbing, activation of caspase 3/7 and formation of apoptotic DNA fragments proved that the active and cancer selective peptides, e.g. R-DIM-P-LF11-322, trigger apoptosis, whereas highly active, though non-selective peptides, such as DIM-LF11-318 and RW-AH seem to kill rapidly via necrosis inducing membrane lyses. Structural studies revealed specific toxicity on cancer cells by peptide derivatives with loop structures, whereas non-specific peptides comprised α-helical structures without loop. Model studies with the cancer membrane mimic phosphatidylserine (PS) gave strong evidence that PS only exposed by cancer cells is an important target for specific hLFcin derivatives. Other negatively charged membrane exposed molecules as sialic acid, heparan and chondroitin sulfate were shown to have minor impact on peptide activity. Copyright © 2015. Published by Elsevier B.V.

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

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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.

Peptides in headlock--a novel high-affinity and versatile peptide-binding nanobody for proteomics and microscopy.

Science.gov (United States)

Braun, Michael B; Traenkle, Bjoern; Koch, Philipp A; Emele, Felix; Weiss, Frederik; Poetz, Oliver; Stehle, Thilo; Rothbauer, Ulrich

2016-01-21

Nanobodies are highly valuable tools for numerous bioanalytical and biotechnical applications. Here, we report the characterization of a nanobody that binds a short peptide epitope with extraordinary affinity. Structural analysis reveals an unusual binding mode where the extended peptide becomes part of a β-sheet structure in the nanobody. This interaction relies on sequence-independent backbone interactions augmented by a small number of specificity-determining side chain contacts. Once bound, the peptide is fastened by two nanobody side chains that clamp it in a headlock fashion. Exploiting this unusual binding mode, we generated a novel nanobody-derived capture and detection system. Matrix-coupled nanobody enables the fast and efficient isolation of epitope-tagged proteins from prokaryotic and eukaryotic expression systems. Additionally, the fluorescently labeled nanobody visualizes subcellular structures in different cellular compartments. The high-affinity-binding and modifiable peptide tag of this system renders it a versatile and robust tool to combine biochemical analysis with microscopic studies.

Transferrin-derived synthetic peptide induces highly conserved pro-inflammatory responses of macrophages.

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Haddad, George; Belosevic, Miodrag

2009-02-01

We examined the induction of macrophage pro-inflammatory responses by transferrin-derived synthetic peptide originally identified following digestion of transferrin from different species (murine, bovine, human N-lobe and goldfish) using elastase. The mass spectrometry analysis of elastase-digested murine transferrin identified a 31 amino acid peptide located in the N2 sub-domain of the transferrin N-lobe, that we named TMAP. TMAP was synthetically produced and shown to induce a number of pro-inflammatory genes by quantitative PCR. TMAP induced chemotaxis, a potent nitric oxide response, and TNF-alpha secretion in different macrophage populations; P338D1 macrophage-like cells, mouse peritoneal macrophages, mouse bone marrow-derived macrophages (BMDM) and goldfish macrophages. The treatment of BMDM cultures with TMAP stimulated the production of nine cytokines and chemokines (IL-6, MCP-5, MIP-1 alpha, MIP-1 gamma, MIP-2, GCSF, KC, VEGF, and RANTES) that was measured using cytokine antibody array and confirmed by Western blot. Our results indicate that transferrin-derived peptide, TMAP, is an immunomodulating molecule capable of inducing pro-inflammatory responses in lower and higher vertebrates.

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

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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.

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

Characterization of trypsin-derived peptides acrylamide-adducted hemoglobin

International Nuclear Information System (INIS)

Springer, D.L.; Goheen, S.C.; Edmonds, C.G.; McCulloch, M.; Sylvester, D.M.; Sander, C.; Bull, R.J.

1991-01-01

Even though there are a number of sources for human exposure to acrylamide, reliable biomarkers of exposure are not available. In an effort to develop such a biomarker, the authors are characterizing peptides derived from trypsin digests of acrylamide-adducted hemoglobin. For this, radiolabeled acrylamide was incubated with this, radiolabeled acrylamide was incubated with purified human hemoglobin (Ao) and decomposition products removed by dialysis. When the adducted hemoglobin was separated by reverse-phase HPLC, radioactivity eluted with the α and β subunits, suggesting covalent binding. Digestion of individual subunits with trypsin followed by reverse phase HPLC, indicated that most of the radioactivity associated with the α subunit co-eluted with a single peptide. Similar results were observed for the β subunit except that significant amounts of radioactivity eluted with the solvent front, suggesting that radioactivity was released by trypsin digestion. Currently, these preparation are under further characterization by electrospray ionization mass spectrometry. This approach will aid in the identification of the adducted will aid in the identification of the adducted peptide and subsequent preparation of an acrylamide-specific antibody

[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.

Laminin-111-derived peptide conjugated fibrin hydrogel restores salivary gland function.

Directory of Open Access Journals (Sweden)

Kihoon Nam

Full Text Available Hyposalivation reduces the patient quality of life, as saliva is important for maintaining oral health. Current treatments for hyposalivation are limited to medications such as the muscarinic receptor agonists, pilocarpine and cevimeline. However, these therapies only provide temporary relief. Therefore, alternative therapies are essential to restore salivary gland function. An option is to use bioengineered scaffolds to promote functional salivary gland regeneration. Previous studies demonstrated that the laminin-111 protein is critical for intact salivary gland cell cluster formation and organization. However, laminin-111 protein as a whole is not suitable for clinical applications as some protein domains may contribute to unwanted side effects such as degradation, tumorigenesis and immune responses. Conversely, the use of synthetic laminin-111 peptides makes it possible to minimize the immune reactivity or pathogen transfer. In addition, it is relatively simple and inexpensive as compared to animal-derived proteins. Therefore, the goal of this study was to demonstrate whether a 20 day treatment with laminin-111-derived peptide conjugated fibrin hydrogel promotes tissue regeneration in submandibular glands of a wound healing mouse model. In this study, laminin-111-derived peptide conjugated fibrin hydrogel significantly accelerated formation of salivary gland tissue. The regenerated gland tissues displayed not only structural but also functional restoration.

Lysine-Derived Protein-Bound Heyns Compounds in Bakery Products.

Science.gov (United States)

Treibmann, Stephanie; Hellwig, Anne; Hellwig, Michael; Henle, Thomas

2017-12-06

Fructose and dicarbonyl compounds resulting from fructose in heated foods have been linked to pathophysiological pathways of several metabolic disorders. Up to now, very little has been known about the Maillard reaction of fructose in food. Heyns rearrangement compounds (HRCs), the first stable intermediates of the Maillard reaction between amino components and fructose, have not yet been quantitated as protein-bound products in food. Therefore, the HRCs glucosyllysine and mannosyllysine were synthesized and characterized by NMR. Protein-bound HRCs in cookies containing various sugars and in commercial bakery products were quantitated after enzymatic hydrolysis by RP-HPLC-ESI-MS/MS in the multiple reaction monitoring mode through application of the standard addition method. Protein-bound HRCs were quantitated for the first time in model cookies and in commercial bakery products containing honey, banana, and invert sugar syrup. Concentrations of HRCs from 19 to 287 mg/kg were found, which were similar to or exceeded the content of other frequently analyzed Maillard reaction products, such as N-ε-carboxymethyllysine (10-76 mg/kg), N-ε-carboxyethyllysine (2.5-53 mg/kg), and methylglyoxal-derived hydroimidazolone 1 (10-218 mg/kg) in the analyzed cookies. These results show that substantial amounts of HRCs form during food processing. Analysis of protein-bound HRCs in cookies is therefore useful to evaluate the Maillard reaction of fructose.

Antimicrobial activity of the indolicidin-derived novel synthetic peptide In-58.

Science.gov (United States)

Vasilchenko, A S; Vasilchenko, A V; Pashkova, T M; Smirnova, M P; Kolodkin, N I; Manukhov, I V; Zavilgelsky, G B; Sizova, E A; Kartashova, O L; Simbirtsev, A S; Rogozhin, E A; Duskaev, G K; Sycheva, M V

2017-12-01

Natural peptides with antimicrobial activity are extremely diverse, and peptide synthesis technologies make it possible to significantly improve their properties for specific tasks. Here, we investigate the biological properties of the natural peptide indolicidin and the indolicidin-derived novel synthetic peptide In-58. In-58 was generated by replacing all tryptophan residues on phenylalanine in D-configuration; the α-amino group in the main chain also was modified by unsaturated fatty acid. Compared with indolicidin, In-58 is more bactericidal, more resistant to proteinase K, and less toxic to mammalian cells. Using molecular physics approaches, we characterized the action of In-58 on bacterial cells at the cellular level. Also, we have found that studied peptides damage bacterial membranes. Using the Escherichia coli luminescent biosensor strain MG1655 (pcolD'::lux), we investigated the action of indolicidin and In-58 at the subcellular level. At subinhibitory concentrations, indolicidin and In-58 induced an SOS response. Our data suggest that indolicidin damages the DNA, but bacterial membrane perturbation is its principal mode of action. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.

Peptides in headlock – a novel high-affinity and versatile peptide-binding nanobody for proteomics and microscopy

Science.gov (United States)

Braun, Michael B.; Traenkle, Bjoern; Koch, Philipp A.; Emele, Felix; Weiss, Frederik; Poetz, Oliver; Stehle, Thilo; Rothbauer, Ulrich

2016-01-01

Nanobodies are highly valuable tools for numerous bioanalytical and biotechnical applications. Here, we report the characterization of a nanobody that binds a short peptide epitope with extraordinary affinity. Structural analysis reveals an unusual binding mode where the extended peptide becomes part of a β-sheet structure in the nanobody. This interaction relies on sequence-independent backbone interactions augmented by a small number of specificity-determining side chain contacts. Once bound, the peptide is fastened by two nanobody side chains that clamp it in a headlock fashion. Exploiting this unusual binding mode, we generated a novel nanobody-derived capture and detection system. Matrix-coupled nanobody enables the fast and efficient isolation of epitope-tagged proteins from prokaryotic and eukaryotic expression systems. Additionally, the fluorescently labeled nanobody visualizes subcellular structures in different cellular compartments. The high-affinity-binding and modifiable peptide tag of this system renders it a versatile and robust tool to combine biochemical analysis with microscopic studies. PMID:26791954

Lumazine Peptides from the Marine-Derived Fungus Aspergillus terreus

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Minjung You

2015-03-01

Full Text Available Terrelumamides A (1 and B (2, two new lumazine-containing peptides, were isolated from the culture broth of the marine-derived fungus Aspergillus terreus. From the results of combined spectroscopic and chemical analyses, the structures of these compounds were determined to be linear assemblies of 1-methyllumazine-6-carboxylic acid, an amino acid residue and anthranilic acid methyl ester connected by peptide bonds. These new compounds exhibited pharmacological activity by improving insulin sensitivity, which was evaluated in an adipogenesis model using human bone marrow mesenchymal stem cells. In addition, the compounds exhibited fluorescence changes upon binding to DNA, demonstrating their potential applications to DNA sequence recognition.

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

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

Hemopressins and other hemoglobin-derived peptides in mouse brain: Comparison between brain, blood, and heart peptidome and regulation in Cpefat/fat mice

Science.gov (United States)

Gelman, Julia S.; Sironi, Juan; Castro, Leandro M.; Ferro, Emer S.; Fricker, Lloyd D.

2010-01-01

Many hemoglobin-derived peptides are present in mouse brain, and several of these have bioactive properties including the hemopressins, a related series of peptides that bind to cannabinoid CB1 receptors. Although hemoglobin is a major component of red blood cells, it is also present in neurons and glia. To examine whether the hemoglobin-derived peptides in brain are similar to those present in blood and heart, we used a peptidomics approach involving mass spectrometry. Many hemoglobin-derived peptides are found only in brain and not in blood, whereas all hemoglobin-derived peptides found in heart were also seen in blood. Thus, it is likely that the majority of the hemoglobin-derived peptides detected in brain are produced from brain hemoglobin and not erythrocytes. We also examined if the hemopressins and other major hemoglobin-derived peptides were regulated in the Cpefat/fat mouse; previously these mice were reported to have elevated levels of several hemoglobin-derived peptides. Many, but not all of the hemoglobin-derived peptides were elevated in several brain regions of the Cpefat/fat mouse. Taken together, these findings suggest that the post-translational processing of alpha and beta hemoglobin into the hemopressins, as well as other peptides, is upregulated in some but not all Cpefat/fat mouse brain regions. PMID:20202081

PreproVIP-derived peptides in the human female genital tract: expression and biological function

DEFF Research Database (Denmark)

Bredkjoer, H E; Palle, C; Ekblad, E

1997-01-01

The aim of the study was to elucidate the localization, distribution, colocalization and biological effect of preproVIP-derived peptides in the human female genital tract. Radioimmunoassays applying antisera against the five functional domains of the VIP precursor in combination with immunohistoc......The aim of the study was to elucidate the localization, distribution, colocalization and biological effect of preproVIP-derived peptides in the human female genital tract. Radioimmunoassays applying antisera against the five functional domains of the VIP precursor in combination...... with immunohistochemistry were used. The effect of preproVIP 22-79, preproVIP 111-122 and preproVIP 156-170 on genital smooth muscle activity in the Fallopian tube was investigated in vitro and compared to that of VIP. All the preproVIP-derived peptides were expressed throughout the genital tract in neuronal elements...

Dissecting the Structure-Function Relationship of a Fungicidal Peptide Derived from the Constant Region of Human Immunoglobulins

OpenAIRE

Ciociola, Tecla; Pertinhez, Thelma A.; Giovati, Laura; Sperindè, Martina; Magliani, Walter; Ferrari, Elena; Gatti, Rita; D'Adda, Tiziana; Spisni, Alberto; Conti, Stefania; Polonelli, Luciano

2016-01-01

Synthetic peptides encompassing sequences related to the complementarity-determining regions of antibodies or derived from their constant region (Fc peptides) were proven to exert differential antimicrobial, antiviral, antitumor, and/or immunomodulatory activities in vitro and/or in vivo, regardless of the specificity and isotype of the parental antibody. Alanine substitution derivatives of these peptides exhibited unaltered, increased, or decreased candidacidal activities in vitro. The bioac...

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

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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/.

Alpha-amidated peptides derived from pro-opiomelanocortin in human pituitary tumours

DEFF Research Database (Denmark)

Fenger, M; Johnsen, A H

1988-01-01

Human pituitary tumours, obtained at surgery for Cushing's disease and Nelson's syndrome, were extracted and the content and molecular forms of pro-opiomelanocortin (POMC)-derived peptides determined by radioimmunoassay, gel chromatography, reversed-phase high-performance liquid chromatography....... In conclusion, all the molecular forms of the amidated peptides detected in tumours from patients with Cushing's disease and Nelson's syndrome were similar to the molecular forms found in the normal human pituitary. The main difference between the tumours and the normal pituitary was the greater amount...... (HPLC) and sequence analysis. In the tumours from patients with Cushing's disease the mean concentrations of amidated peptides relative to the total amount of POMC were as follows: alpha-MSH, 1.7%; amidated gamma-MSH (gamma 1-MSH), 8.5% and the peptide linking gamma-MSH and ACTH in the precursor (hinge...

Site-selective modification of peptides: From "customizable units" to novel α-aryl and α-alkyl glycine derivatives, and components of branched peptides.

Science.gov (United States)

Romero-Estudillo, Iván; Saavedra, Carlos; Boto, Alicia; Álvarez, Eleuterio

2015-09-01

The creation of peptide libraries by site-selective modification of a few peptide substrates would increase the efficiency of discovery processes, but still is a real synthetic challenge. The site-selective modification of small peptides at serine or threonine residues, by using a short scission-addition procedure, allows the preparation of peptides with unnatural α-aryl glycines. In a similar way, the scission of hydroxyproline residues is the key step in the production of optically pure α-alkyl glycines which are precursors or components of branched peptides. With these versatile processes, a single peptide can be transformed into a variety of peptide derivatives. The process takes place under mild conditions, and good global yields are obtained. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 104: 650-662, 2015. © 2015 Wiley Periodicals, Inc.

Crystallization and preliminary X-ray crystallographic analysis of peptide deformylase (PDF) from Bacillus cereus in ligand-free and actinonin-bound forms

International Nuclear Information System (INIS)

Park, Joon Kyu; Moon, Jin Ho; Kim, Jae-Hong; Kim, Eunice EunKyeong

2004-01-01

Peptide deformylase (PDF) from B. cereus has been overexpressed, purified and crystallized in ligand-free and actinonin-bound forms. Diffraction data have been collected from these crystals to 1.7 and 2.0 Å resolution, respectively. In bacteria, protein expression initiates with an N-formyl group and this needs to be removed in order to ensure proper bacterial growth. These formylation and deformylation processes are unique to eubacteria; therefore, inhibition of these would provide a novel antibacterial therapy. Deformylation is carried out by peptide deformylase (PDF). PDF from Bacillus cereus, one of the major pathogenic bacteria, was cloned into expression plasmid pET-28a (Novagen), overexpressed in Escherichia coli BL21 (DE3) and purified to high quality. Crystals have been obtained of both ligand-free PDF and PDF to which actinonin, a highly potent naturally occurring inhibitor, is bound. Both crystals belong to space group P2 1 2 1 2 1 , with unit-cell parameters a = 42.72, b = 44.04, c = 85.19 Å and a = 41.31, b = 44.56, c = 84.47 Å, respectively. Diffraction data were collected to 1.7 Å resolution for the inhibitor-free crystals and to 2.0 Å resolution for the actinonin-bound crystals

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

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....

MHC class II-derived peptides can bind to class II molecules, including self molecules, and prevent antigen presentation

DEFF Research Database (Denmark)

Rosloniec, E F; Vitez, L J; Buus, S

1990-01-01

the alpha k-3 peptide binds slightly less well. These combined data, suggesting that class II-derived peptides can bind to MHC class II molecules, including the autologous molecule from which they are derived, have important implications for the molecular basis of alloreactivity and autoreactivity. Further...... found in the first and third polymorphic regions (PMR) of the A alpha k chain (alpha k-1 and alpha k-3) were capable of inhibiting the presentation of three different HEL-derived peptide antigens to their appropriate T cells. In addition, the alpha k-1 peptide inhibited the presentation of the OVA(323......-339) immunodominant peptide to the I-Ad-restricted T cell hybridomas specific for it. Prepulsing experiments demonstrated that the PMR peptides were interacting with the APC and not with the T cell hybridomas. These observations were confirmed and extended by the demonstration that the alpha k-1 and alpha k-3...

Efficient generation of dopamine neuron-like cells from skin-derived precursors with a synthetic peptide derived from von Hippel-Lindau protein.

Science.gov (United States)

Kubo, Atsuhiko; Yoshida, Tetsuhiko; Kobayashi, Nahoko; Yokoyama, Takaakira; Mimura, Toshiro; Nishiguchi, Takao; Higashida, Tetsuhiro; Yamamoto, Isao; Kanno, Hiroshi

2009-12-01

Skin-derived precursors (SKPs) from mammalian dermis represent neural crest-related stem cells capable of differentiating into both neural and mesodermal progency. SKPs are of clinical interest because they serve as accessible autologous donor cells for neuronal repair for neuronal intractable diseases. However, little is known about the efficient generation of neurons from SKPs, and phenotypes of neurons generated from SKPs have been restricted. In addition, the neuronal repair using their generated neurons as donor cells has not been achieved. The von Hippel-Lindau protein (pVHL) is one of the proteins that play an important role during neuronal differentiation, and recently neuronal differentiation of neural progenitor cells by intracellular delivery of a synthetic VHL peptide derived from elongin BC-binding site has been demonstrated. In the present study, a synthetic VHL peptide derived from elongin BC-binding site was conjugated to the protein transduction domain (PTD) of HIV-TAT protein (TATVHL peptide) to facilitate entry into cells, and we demonstrate the efficient generation of cells with dopaminergic phenotype from SKPs with the intracellular delivery of TATVHL peptide, and characterized the generated cells. The TATVHL peptide-treated SKPs expressed neuronal marker proteins, particularly dopamine neuron markers, and also up-regulated mRNA levels of proneural basic helix-loop-helix factors. After the TATVHL peptide treatment, transplanted SKPs into Parkinson's disease (PD) model rats sufficiently differentiated into dopamine neuron-like cells in PD model rats, and partially but significantly corrected behavior of PD model rats. The generated dopamine neuron-like cells are expected to serve as donor cells for neuronal repair for PD.

The remarkable stability of chimeric, sialic acid-derived alpha/delta-peptides in human blood plasma.

Science.gov (United States)

Saludes, Jonel P; Natarajan, Arutselvan; DeNardo, Sally J; Gervay-Hague, Jacquelyn

2010-05-01

Peptides are labile toward proteolytic enzymes, and structural modifications are often required to prolong their metabolic half-life and increase resistance. One modification is the incorporation of non-alpha-amino acids into the peptide to deter recognition by hydrolytic enzymes. We previously reported the synthesis of chimeric alpha/delta-peptides from glutamic acids (Glu) and the sialic acid derivative Neu2en. Conformational analyses revealed these constructs adopt secondary structures in water and may serve as conformational surrogates of polysialic acid. Polysialic acid is a tumor-associated polysaccharide and is correlated with cancer metastasis. Soluble polysialic acid is rapidly cleared from the blood limiting its potential for vaccine development. One motivation in developing structural surrogates of polysialic acid was to create constructs with increased bioavailability. Here, we report plasma stability profiles of Glu/Neu2en alpha/delta-peptides. DOTA was conjugated at the peptide N-termini by solid phase peptide synthesis, radiolabeled with (111)In, incubated in human blood plasma at 37 degrees C, and their degradation patterns monitored by cellulose acetate electrophoresis and radioactivity counting. Results indicate that these peptides exhibit a long half-life that is two- to three-orders of magnitude higher than natural alpha-peptides. These findings provide a viable platform for the synthesis of plasma stable, sialic acid-derived peptides that may find pharmaceutical application.

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.

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.

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.

Science.gov (United States)

Morales, Lucia; Mateos-Gomez, Pedro A; Capiscol, Carmen; del Palacio, Lorena; Enjuanes, Luis; Sola, Isabel

2013-11-01

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. The integrity of the entire sequence domain was necessary because deletion of any of the five structural motifs defined within this region abrogated specific packaging of this viral RNA. One of these RNA motifs was the stem-loop SL5, a highly conserved motif in coronaviruses located at nucleotide positions 106 to 136. Partial deletion or point mutations within this motif also abrogated packaging. Using TGEV-derived defective minigenomes replicated in trans by a helper virus, we have shown that TGEV RNA packaging is a replication-independent process. Furthermore, the last 494 nt of the genomic 3' end were not essential for packaging, although this region increased packaging efficiency. TGEV RNA sequences identified as necessary for viral genome packaging were not sufficient to direct packaging of a heterologous sequence derived from the green fluorescent protein gene. These results indicated that TGEV genome packaging is a complex process involving many factors in addition to the identified RNA packaging signal. The identification of well-defined RNA motifs within the TGEV RNA genome that are essential for packaging will be useful for designing packaging-deficient biosafe coronavirus-derived vectors and providing new targets for antiviral therapies.

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

Science.gov (United States)

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

I-Ad-binding peptides derived from unrelated protein antigens share a common structural motif

DEFF Research Database (Denmark)

Sette, A; Buus, S; Colon, S

1988-01-01

on the I-Ad binding of the immunogenic peptide OVA 323-339. The results obtained demonstrated the very permissive nature of Ag-Ia interaction. We also showed that unrelated peptides that are good I-Ad binders share a common structural motif and speculated that recognition of such motifs could represent...... that I-Ad molecules recognize a large library of Ag by virtue of common structural motifs present in peptides derived from phylogenetically unrelated proteins....

A Review of Antioxidant Peptides Derived from Meat Muscle and By-Products

Directory of Open Access Journals (Sweden)

Rui Liu

2016-09-01

Full Text Available Antioxidant peptides are gradually being accepted as food ingredients, supplemented in functional food and nutraceuticals, to positively regulate oxidative stress in the human body against lipid and protein oxidation. Meat muscle and meat by-products are rich sources of proteins and can be regarded as good materials for the production of bioactive peptides by use of enzymatic hydrolysis or direct solvent extraction. In recent years, there has been a growing number of studies conducted to characterize antioxidant peptides or hydrolysates derived from meat muscle and by-products as well as processed meat products, including dry-cured hams. Antioxidant peptides obtained from animal sources could exert not only nutritional value but also bioavailability to benefit human health. This paper reviews the antioxidant peptides or protein hydrolysates identified in muscle protein and by-products. We focus on the procedure for the generation of peptides with antioxidant capacity including the acquisition of crude peptides, the assessment of antioxidant activity, and the purification and identification of the active fraction. It remains critical to perform validation experiments with a cell model, animal model or clinical trial to eliminate safety concerns before final application in the food system. In addition, some of the common characteristics on structure-activity relationship are also reviewed based on the identified antioxidant peptides.

A Review of Antioxidant Peptides Derived from Meat Muscle and By-Products.

Science.gov (United States)

Liu, Rui; Xing, Lujuan; Fu, Qingquan; Zhou, Guang-Hong; Zhang, Wan-Gang

2016-09-20

Antioxidant peptides are gradually being accepted as food ingredients, supplemented in functional food and nutraceuticals, to positively regulate oxidative stress in the human body against lipid and protein oxidation. Meat muscle and meat by-products are rich sources of proteins and can be regarded as good materials for the production of bioactive peptides by use of enzymatic hydrolysis or direct solvent extraction. In recent years, there has been a growing number of studies conducted to characterize antioxidant peptides or hydrolysates derived from meat muscle and by-products as well as processed meat products, including dry-cured hams. Antioxidant peptides obtained from animal sources could exert not only nutritional value but also bioavailability to benefit human health. This paper reviews the antioxidant peptides or protein hydrolysates identified in muscle protein and by-products. We focus on the procedure for the generation of peptides with antioxidant capacity including the acquisition of crude peptides, the assessment of antioxidant activity, and the purification and identification of the active fraction. It remains critical to perform validation experiments with a cell model, animal model or clinical trial to eliminate safety concerns before final application in the food system. In addition, some of the common characteristics on structure-activity relationship are also reviewed based on the identified antioxidant peptides.

New dendrimer - peptide host - guest complexes : towards dendrimers as peptide carriers

NARCIS (Netherlands)

Boas, U.; Sontjens, S.H.M.; Jensen, K.J.; Christensen, J.B.; Meijer, E.W.

2002-01-01

Adamantyl urea and adamantyl thiourea modified poly(propylene imine) dendrimers act as hosts for N-terminal tert-butoxycarbonyl (Boc)-protected peptides and form chloroform-soluble complexes. investigations with NMR spectroscopy show that the peptide is bound to the dendrimer by ionic interactions

Treatment of Experimental Brain Tumors with Trombospondin-1 Derived Peptides: an In Vivo Imaging Study

Directory of Open Access Journals (Sweden)

A. Bogdanov, Jr.

1999-11-01

Full Text Available Antiangiogenic and antiproliferative effects of synthetic D-reverse peptides derived from the type 1 repeats of thrombospondin (TSP1 [1,2] were studied in rodent C6 glioma and 9L gliosarcomas. To directly measure tumor size and vascular parameters, we employed in vivo magnetic resonance (MR imaging and corroborated results by traditional morphometric tissue analysis. Rats bearing either C6 or 9L tumors were treated with TSP1-derived peptide (D-reverse amKRFKQDGGWSHWSPWSSac, n=13 or a control peptide (D-reverse am KRAKQAGGASHASPASSac, n=12 at 10 mg/kg, administered either intravenously or through subcutaneous miniosmotic pumps starting 10 days after tumor implantation. Eleven days later, the effect of peptide treatment was evaluated. TSP1 peptide-treated 9L tumors (50.7±44.2 mm3, n=7 and C6 tumors (41.3±34.2 mm3, n=6 were significantly smaller than tumors treated with control peptide (9L: 215.7±67.8 mm3, n=6; C6:184.2±105.2 mm3, n=6. In contrast, the in vivo vascular volume fraction, the mean vascular area (determined by microscopy, and the microvascular density of tumors were not significantly different in any of the experimental groups. In cell culture, TSP1, and the amKRFKQDGGWSHWSPWSSac peptide showed antiproliferative effects against C6 with an IC of 45 nM for TSP1. These results indicate that TSP1derived peptides retard brain tumor growth presumably as a result of slower de novo blood vessel formation and synergistic direct antiproliferative effects on tumor cells. We also show that in vivo MR imaging can be used to assess treatment efficacy of novel antiangiogenic drugs non-invasively, which has obvious implications for clinical trials.

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

Studies on lactoferricin-derived Escherichia coli membrane-active peptides reveal differences in the mechanism of N-acylated versus nonacylated peptides.

Science.gov (United States)

Zweytick, Dagmar; Deutsch, Günter; Andrä, Jörg; Blondelle, Sylvie E; Vollmer, Ekkehard; Jerala, Roman; Lohner, Karl

2011-06-17

To improve the low antimicrobial activity of LF11, an 11-mer peptide derived from human lactoferricin, mutant sequences were designed based on the defined structure of LF11 in the lipidic environment. Thus, deletion of noncharged polar residues and strengthening of the hydrophobic N-terminal part upon adding a bulky hydrophobic amino acid or N-acylation resulted in enhanced antimicrobial activity against Escherichia coli, which correlated with the peptides' degree of perturbation of bacterial membrane mimics. Nonacylated and N-acylated peptides exhibited different effects at a molecular level. Nonacylated peptides induced segregation of peptide-enriched and peptide-poor lipid domains in negatively charged bilayers, although N-acylated peptides formed small heterogeneous domains resulting in a higher degree of packing defects. Additionally, only N-acylated peptides perturbed the lateral packing of neutral lipids and exhibited increased permeability of E. coli lipid vesicles. The latter did not correlate with the extent of improvement of the antimicrobial activity, which could be explained by the fact that elevated binding of N-acylated peptides to lipopolysaccharides of the outer membrane of gram-negative bacteria seems to counteract the elevated membrane permeabilization, reflected in the respective minimal inhibitory concentration for E. coli. The antimicrobial activity of the peptides correlated with an increase of membrane curvature stress and hence bilayer instability. Transmission electron microscopy revealed that only the N-acylated peptides induced tubular protrusions from the outer membrane, whereas all peptides caused detachment of the outer and inner membrane of E. coli bacteria. Viability tests demonstrated that these bacteria were dead before onset of visible cell lysis.

Studies on Lactoferricin-derived Escherichia coli Membrane-active Peptides Reveal Differences in the Mechanism of N-Acylated Versus Nonacylated Peptides*

Science.gov (United States)

Zweytick, Dagmar; Deutsch, Günter; Andrä, Jörg; Blondelle, Sylvie E.; Vollmer, Ekkehard; Jerala, Roman; Lohner, Karl

2011-01-01

To improve the low antimicrobial activity of LF11, an 11-mer peptide derived from human lactoferricin, mutant sequences were designed based on the defined structure of LF11 in the lipidic environment. Thus, deletion of noncharged polar residues and strengthening of the hydrophobic N-terminal part upon adding a bulky hydrophobic amino acid or N-acylation resulted in enhanced antimicrobial activity against Escherichia coli, which correlated with the peptides' degree of perturbation of bacterial membrane mimics. Nonacylated and N-acylated peptides exhibited different effects at a molecular level. Nonacylated peptides induced segregation of peptide-enriched and peptide-poor lipid domains in negatively charged bilayers, although N-acylated peptides formed small heterogeneous domains resulting in a higher degree of packing defects. Additionally, only N-acylated peptides perturbed the lateral packing of neutral lipids and exhibited increased permeability of E. coli lipid vesicles. The latter did not correlate with the extent of improvement of the antimicrobial activity, which could be explained by the fact that elevated binding of N-acylated peptides to lipopolysaccharides of the outer membrane of Gram-negative bacteria seems to counteract the elevated membrane permeabilization, reflected in the respective minimal inhibitory concentration for E. coli. The antimicrobial activity of the peptides correlated with an increase of membrane curvature stress and hence bilayer instability. Transmission electron microscopy revealed that only the N-acylated peptides induced tubular protrusions from the outer membrane, whereas all peptides caused detachment of the outer and inner membrane of E. coli bacteria. Viability tests demonstrated that these bacteria were dead before onset of visible cell lysis. PMID:21515687

Influence of structural and surface properties of whey-derived peptides on zinc-chelating capacity, and in vitro gastric stability and bioaccessibility of the zinc-peptide complexes.

Science.gov (United States)

Udechukwu, M Chinonye; Downey, Brianna; Udenigwe, Chibuike C

2018-02-01

Gastrointestinal stability of zinc-peptide complexes is essential for zinc delivery. As peptide surface charge can influence their metal complex stability, we evaluated the zinc-chelating capacity and stability of zinc complexes of whey protein hydrolysates (WPH), produced with Everlase (WPH-Ever; ζ-potential, -39mV) and papain (WPH-Pap; ζ-potential, -7mV), during simulated digestion. WPH-Ever had lower amount of zinc-binding amino acids but showed higher zinc-chelating capacity than WPH-Pap. This is attributable to the highly anionic surface charge of WPH-Ever for electrostatic interaction with zinc. Release of zinc during peptic digestion was lower for WPH-Ever-zinc, and over 50% of zinc remained bound in both peptide complexes after peptic-pancreatic digestion. Fourier transform infrared spectroscopy suggests the involvement of carboxylate ion, and sidechain carbon-oxygen of aspartate/glutamate and serine/threonine in zinc-peptide complexation. The findings indicate that strong zinc chelation can promote gastric stability and impede intestinal release, for peptides intended for use as dietary zinc carriers. Copyright © 2017 Elsevier Ltd. All rights reserved.

δ-Peptides from RuAAC-Derived 1,5-Disubstituted Triazole Units

KAUST Repository

Johansson, Johan R.

2014-02-14

Non-natural peptides with structures and functions similar to natural peptides have emerged lately in biomedical as well as nanotechnological contexts. They are interesting for pharmaceutical applications since they can adopt structures with new targeting potentials and because they are generally not prone to degradation by proteases. We report here a new set of peptidomimetics derived from δ-peptides, consisting of n units of a 1,5-disubstituted 1,2,3-triazole amino acid (5Tzl). The monomer was prepared using ruthenium-catalyzed azide-alkyne cycloaddition (RuAAC) chemistry using [RuCl2Cp]x as the catalyst, allowing for simpler purification and resulting in excellent yields. This achiral monomer was used to prepare peptide oligomers that are water soluble independent of peptide chain length. Conformational analysis and structural investigations of the oligomers were performed by 2D NOESY NMR experiments, and by quantum chemical calculations using the ωB97X-D functional. These data indicate that several conformations may co-exist with slight energetic differences. Together with their increased hydrophilicity, this feature of homo-5Tzl may prove essential for mimicking natural peptides composed of α-amino acids, where the various secondary structures are achieved by side chain effects and not by the rigidity of the peptide backbone. The improved synthetic method allows for facile variation of the 5Tzl amino acid side chains, further increasing the versatility of these compounds. A new set of non-natural peptides composed of 1,5-disubstituted 1,2,3-triazole amino acids is presented. These peptides benefit from: a) modular synthesis of the monomers, allowing variation of the side chains; b) increased solubility of the oligomers in water, irrespective of peptide length; c) flexibility of the backbone allowing these foldamers to adopt several conformations. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Thiol-disulfide exchange in peptides derived from human growth hormone.

Science.gov (United States)

Chandrasekhar, Saradha; Epling, Daniel E; Sophocleous, Andreas M; Topp, Elizabeth M

2014-04-01

Disulfide bonds stabilize proteins by cross-linking distant regions into a compact three-dimensional structure. They can also participate in hydrolytic and oxidative pathways to form nonnative disulfide bonds and other reactive species. Such covalent modifications can contribute to protein aggregation. Here, we present experimental data for the mechanism of thiol-disulfide exchange in tryptic peptides derived from human growth hormone in aqueous solution. Reaction kinetics was monitored to investigate the effect of pH (6.0-10.0), temperature (4-50°C), oxidation suppressants [ethylenediaminetetraacetic acid (EDTA) and N2 sparging], and peptide secondary structure (amide cyclized vs. open form). The concentrations of free thiol containing peptides, scrambled disulfides, and native disulfide-linked peptides generated via thiol-disulfide exchange and oxidation reactions were determined using reverse-phase HPLC and liquid chromatography-mass spectrometry. Concentration versus time data were fitted to a mathematical model using nonlinear least squares regression analysis. At all pH values, the model was able to fit the data with R(2) ≥ 0.95. Excluding oxidation suppressants (EDTA and N2 sparging) resulted in an increase in the formation of scrambled disulfides via oxidative pathways but did not influence the intrinsic rate of thiol-disulfide exchange. In addition, peptide secondary structure was found to influence the rate of thiol-disulfide exchange. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

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

Intracellular protein delivery activity of peptides derived from insulin-like growth factor binding proteins 3 and 5

International Nuclear Information System (INIS)

Goda, Natsuko; Tenno, Takeshi; Inomata, Kosuke; Shirakawa, Masahiro; Tanaka, Toshiki; Hiroaki, Hidekazu

2008-01-01

Insulin-like growth factor binding proteins (IGFBPs) have various IGF-independent cellular activities, including receptor-independent cellular uptake followed by transcriptional regulation, although mechanisms of cellular entry remain unclear. Herein, we focused on their receptor-independent cellular entry mechanism in terms of protein transduction domain (PTD) activity, which is an emerging technique useful for clinical applications. The peptides of 18 amino acid residues derived from IGFBP-3 and IGFBP-5, which involve heparin-binding regions, mediated cellular delivery of an exogenous protein into NIH3T3 and HeLa cells. Relative protein delivery activities of IGFBP-3/5-derived peptides were approximately 20-150% compared to that of the HIV-Tat peptide, a potent PTD. Heparin inhibited the uptake of the fusion proteins with IGFBP-3 and IGFBP-5, indicating that the delivery pathway is heparin-dependent endocytosis, similar to that of HIV-Tat. The delivery of GST fused to HIV-Tat was competed by either IGFBP-3 or IGFBP-5-derived synthetic peptides. Therefore, the entry pathways of the three PTDs are shared. Our data has shown a new approach for designing protein delivery systems using IGFBP-3/5 derived peptides based on the molecular mechanisms of IGF-independent activities of IGFBPs

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.

A general strategy to endow natural fusion-protein-derived peptides with potent antiviral activity.

Directory of Open Access Journals (Sweden)

Antonello Pessi

Full Text Available Fusion between the viral and target cell membranes is an obligatory step for the infectivity of all enveloped virus, and blocking this process is a clinically validated therapeutic strategy.Viral fusion is driven by specialized proteins which, although specific to each virus, act through a common mechanism, the formation of a complex between two heptad repeat (HR regions. The HR regions are initially separated in an intermediate termed "prehairpin", which bridges the viral and cell membranes, and then fold onto each other to form a 6-helical bundle (6HB, driving the two membranes to fuse. HR-derived peptides can inhibit viral infectivity by binding to the prehairpin intermediate and preventing its transition to the 6HB.The antiviral activity of HR-derived peptides differs considerably among enveloped viruses. For weak inhibitors, potency can be increased by peptide engineering strategies, but sequence-specific optimization is time-consuming. In seeking ways to increase potency without changing the native sequence, we previously reported that attachment to the HR peptide of a cholesterol group ("cholesterol-tagging" dramatically increases its antiviral potency, and simultaneously increases its half-life in vivo. We show here that antiviral potency may be increased by combining cholesterol-tagging with dimerization of the HR-derived sequence, using as examples human parainfluenza virus, Nipah virus, and HIV-1. Together, cholesterol-tagging and dimerization may represent strategies to boost HR peptide potency to levels that in some cases may be compatible with in vivo use, possibly contributing to emergency responses to outbreaks of existing or novel viruses.

PURIFICATION OF ANGIOTENSIN CONVERTING ENZYME INHIBITORY PEPTIDE DERIVED FROM KACANG GOAT MEAT PROTEIN HYDROLYSATE

Directory of Open Access Journals (Sweden)

J. Jamhari

2014-10-01

Full Text Available The objective of this study was to identify the Angiotensin Converting Enzyme (ACE inhibitorypeptide derived from Kacang goat meat protein hydrolysate. Kacang goat meat loin section washydrolyzed with pepsin, trypsin and chymotrypsin. Protein hydrolysate of Kacang goat meat was thentested the protein concentration and ACE inhibitory activity. ACE inhibitory peptide of the proteinhydrolysate was purified through several steps of purification by column SEP-PAK Plus C18 Cartridgeand RP-HPLC using a Cosmosil column 5PE-SM, 4.6 x 250　mm. The sequence of amino acid of ACEinhibitory peptide was identified by amino acid sequencer. The results showed that amino acidssequence of ACE inhibitory peptide derived from protein hydrolysate of Kacang goat meat was leu-thrglu-ala-pro-leu-asn-pro-lys-ala-arg- asn-glu-lys. It had a molecular weight (MW of 1581 and occurredat the position of 20th to 33rd residues of b-actin of goat meat protein (Capra hircus. The ACE inhibitoryactivity (IC50 of the peptide was 190 mg/mL or 120 mM.

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.

The persistent prevalence and evolution of cross-family recombinant coronavirus GCCDC1 among a bat population: a two-year follow-up.

Science.gov (United States)

Obameso, Joseph O; Li, Hong; Jia, Hao; Han, Min; Zhu, Shiyan; Huang, Canping; Zhao, Yuhui; Zhao, Min; Bai, Yu; Yuan, Fei; Zhao, Honglan; Peng, Xia; Xu, Wen; Tan, Wenjie; Zhao, Yingze; Yuen, Kwok-Yung; Liu, William J; Lu, Lin; Gao, George F

2017-12-01

Bats are connected with the increasing numbers of emerging and re-emerging viruses that may break the species barrier and spread into the human population. Coronaviruses are one of the most common viruses discovered in bats, which were considered as the natural source of recent human-susceptible coronaviruses, i.e. SARS-COV and MERS-CoV. Our previous study reported the discovery of a bat-derived putative cross-family recombinant coronavirus with a reovirus gene p10, named as Ro-BatCoV GCCDC1. In this report, through a two-year follow-up of a special bat population in one specific cave of south China, we illustrate that Ro-BatCoV GCCDC1 persistently circulates among bats. Notably, through the longitudinal observation, we identified the dynamic evolution of Ro-BatCoV GCCDC1 in bats represented by continuously recombination events. Our study provides the first glimpse of the virus evolution in one longitudinally observed bat population cohort and underlines the surveillance and pre-warning of potential interspecies transmittable viruses in bats.

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

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

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

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

Hotspot autoimmune T cell receptor binding underlies pathogen and insulin peptide cross-reactivity

Science.gov (United States)

Cole, David K.; Bulek, Anna M.; Dolton, Garry; Schauenberg, Andrea J.; Szomolay, Barbara; Trimby, Andrew; Jothikumar, Prithiviraj; Fuller, Anna; Skowera, Ania; Rossjohn, Jamie; Zhu, Cheng; Miles, John J.; Wooldridge, Linda; Rizkallah, Pierre J.; Sewell, Andrew K.

2016-01-01

The cross-reactivity of T cells with pathogen- and self-derived peptides has been implicated as a pathway involved in the development of autoimmunity. However, the mechanisms that allow the clonal T cell antigen receptor (TCR) to functionally engage multiple peptide–major histocompatibility complexes (pMHC) are unclear. Here, we studied multiligand discrimination by a human, preproinsulin reactive, MHC class-I–restricted CD8+ T cell clone (1E6) that can recognize over 1 million different peptides. We generated high-resolution structures of the 1E6 TCR bound to 7 altered peptide ligands, including a pathogen-derived peptide that was an order of magnitude more potent than the natural self-peptide. Evaluation of these structures demonstrated that binding was stabilized through a conserved lock-and-key–like minimal binding footprint that enables 1E6 TCR to tolerate vast numbers of substitutions outside of this so-called hotspot. Highly potent antigens of the 1E6 TCR engaged with a strong antipathogen-like binding affinity; this engagement was governed though an energetic switch from an enthalpically to entropically driven interaction compared with the natural autoimmune ligand. Together, these data highlight how T cell cross-reactivity with pathogen-derived antigens might break self-tolerance to induce autoimmune disease. PMID:27183389

Lacto-ghrestatin, a novel bovine milk-derived peptide, suppresses ghrelin secretion.

Science.gov (United States)

Aoki, Hayato; Nakato, Junya; Mizushige, Takafumi; Iwakura, Hiroshi; Sato, Masaru; Suzuki, Hideyuki; Kanamoto, Ryuhei; Ohinata, Kousaku

2017-07-01

Ghrelin, an endogenous peptide isolated from the stomach, is known to stimulate food intake after peripheral administration. We found that the enzymatic digest of β-lactoglobulin decreases ghrelin secretion from the ghrelin-producing cell line MGN3-1. The peptides present in the digest were comprehensively analyzed using the nanoLC-OrbitrapMS. Among them, we identified that the nonapeptide LIVTQTMKG, corresponding to β-lactoglobulin(1-9), suppresses ghrelin secretion from MGN3-1 cells. We named LIVTQTMKG 'lacto-ghrestatin'. We found that lacto-ghrestatin decreases intracellular cAMP levels and mRNA expression levels of ghrelin production-related genes in MGN3-1 cells. Orally administered lacto-ghrestatin decreases plasma ghrelin levels and food intake in fasted mice. Lacto-ghrestatin is the first food-derived peptide to suppress ghrelin secretion in vitro and in vivo. © 2017 Federation of European Biochemical Societies.

[The Qualitative Analysis of the Amide Derivative of HLDF-6 Peptide and Its Metabolites with the Use of Tritium- and Deuterium-Labeled Derivatives].

Science.gov (United States)

Zolotarev, A; Dadayan, A K; Kost, N V; Voevodina, M E; Sokolov, O Y; Kozik, V S; Shram, S I; Azev, V N; Bocharov, E V; Bogachouk, A P; Lipkin, V M; Myasoedov, N F

2015-01-01

The goal of the study was to elaborate the pharmacokinetics methods of the amide derivative of peptide HLDF-6 (TGENHR-NH2) and its range of nootropic and neuroprotective activity is wide. The hexapeptide 41TGENHR46 is a fragment of the HDLF differentiation factor. It forms the basis for the development of preventive and therapeutic preparations for treating cerebrovascular and neurodegenerative conditions. Pharmacokinetic and molecular mechanisms of the action of the HLDF-6 peptide were studied using tritium- and deuterium-labeled derivatives of this peptide, produced with the use of the high-temperature solid-state catalytic isotope exchange reaction (HSCIE). This reaction was employed to produce the tritium-labeled peptide [3H]TGENHR-NH2 with a molar radioactivity of 230 Ci/mmol and the deuterium-labeled peptide [2H]TGENHR-NH2 with an average deuterium incorporation equal to 10.5 atoms. It was shown by the NMR spectroscopy that the isotope label distribution over the labeled peptide's molecule was uniform, which allowed qualitative analysis ofboth the peptide itself and its fragments in the organism's tissues to be conducted. The newly developed pharmacokinetics method makes it possible to avoid almost completely losses of the peptides under study due to biodegradation during the analysis of tissues. These labeled peptides were used in mice, rats and rabbits to study the pharmacokinetics of the peptide and to calculate the values of its principal pharmacokinetic parameters. Characteristics of its pharmacokinetic profile in the blood were obtained, the hypothesis of pharmacokinetics linearity tested, its metabolism analyzed and its bioavailability value, 34%, calculated. It has been shown that the studied TGENHR-NH2 peptide shows high resistance to hydrolysis in the blood plasma, with dipeptidyl aminopeptidases making the largest contribution to its hydrolysis.

Selective detection of carbohydrates and their peptide conjugates by ESI-MS using synthetic quaternary ammonium salt derivatives of phenylboronic acids.

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Kijewska, Monika; Kuc, Adam; Kluczyk, Alicja; Waliczek, Mateusz; Man-Kupisinska, Aleksandra; Lukasiewicz, Jolanta; Stefanowicz, Piotr; Szewczuk, Zbigniew

2014-06-01

We present new tags based on the derivatives of phenylboronic acid and apply them for the selective detection of sugars and peptide-sugar conjugates in mass spectrometry. We investigated the binding of phenylboronic acid and its quaternary ammonium salt (QAS) derivatives to carbohydrates and peptide-derived Amadori products by HR-MS and MS/MS experiments. The formation of complexes between sugar or sugar-peptide conjugates and synthetic tags was confirmed on the basis of the unique isotopic distribution resulting from the presence of boron atom. Moreover, incorporation of a quaternary ammonium salt dramatically improved the efficiency of ionization in mass spectrometry. It was found that the formation of a complex with phenylboronic acid stabilizes the sugar moiety in glycated peptides, resulting in simplification of the fragmentation pattern of peptide-derived Amadori products. The obtained results suggest that derivatization of phenylboronic acid as QAS is a promising method for sensitive ESI-MS detection of carbohydrates and their conjugates formed by non-enzymatic glycation or glycosylation.

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

Science.gov (United States)

Morales, Lucia; Mateos-Gomez, Pedro A.; Capiscol, Carmen; del Palacio, Lorena; 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. The integrity of the entire sequence domain was necessary because deletion of any of the five structural motifs defined within this region abrogated specific packaging of this viral RNA. One of these RNA motifs was the stem-loop SL5, a highly conserved motif in coronaviruses located at nucleotide positions 106 to 136. Partial deletion or point mutations within this motif also abrogated packaging. Using TGEV-derived defective minigenomes replicated in trans by a helper virus, we have shown that TGEV RNA packaging is a replication-independent process. Furthermore, the last 494 nt of the genomic 3′ end were not essential for packaging, although this region increased packaging efficiency. TGEV RNA sequences identified as necessary for viral genome packaging were not sufficient to direct packaging of a heterologous sequence derived from the green fluorescent protein gene. These results indicated that TGEV genome packaging is a complex process involving many factors in addition to the identified RNA packaging signal. The identification of well-defined RNA motifs within the TGEV RNA genome that are essential for packaging will be useful for designing packaging-deficient biosafe coronavirus-derived vectors and providing new targets for antiviral therapies. PMID:23966403

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.

Human DMBT1-Derived Cell-Penetrating Peptides for Intracellular siRNA Delivery

DEFF Research Database (Denmark)

Tuttolomondo, Martina; Casella, Cinzia; Hansen, Pernille Lund

2017-01-01

tumor 1) is a pattern recognition molecule that interacts with polyanions and recognizes and aggregates bacteria. Taking advantage of these properties, we investigated whether specific synthetic DMBT1-derived peptides could be used to formulate nanoparticles for siRNA administration. Using......-potential, circular dichroism, dynamic light scattering, and transmission electron microscopy revealed negatively charged nanoparticles with an average diameter of 10-800 nm, depending on the reaction conditions, and a spherical or rice-shaped morphology, depending on the peptide and β-helix conformation. We...

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

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

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

Inhibition of HIV-1 infection by synthetic peptides derived CCR5 fragments

International Nuclear Information System (INIS)

Imai, Masaki; Baranyi, Lajos; Okada, Noriko; Okada, Hidechika

2007-01-01

HIV-1 infection requires interaction of viral envelope protein gp160 with CD4 and a chemokine receptor, CCR5 or CXCR4 as entry coreceptor. We designed HIV-inhibitory peptides targeted to CCR5 using a novel computer program (ANTIS), which searched all possible sense-antisense amino acid pairs between proteins. Seven AHBs were found in CCR5 receptor. All AHB peptides were synthesized and tested for their ability to prevent HIV-1 infection to human T cells. A peptide fragment (LC5) which is a part of the CCR5 receptor corresponding to the loop between the fifth and sixth transmembrane regions (amino acids 222-240) proved to inhibit HIV-1 IIIB infection of MT-4 cells. Interaction of these antisense peptides could be involved in sustaining HIV-1 infectivity. LC5 effectively indicated dose-dependent manner, and the suppression was enhanced additively by T20 peptide, which inhibits infection in vitro by disrupting the gp41 conformational changes necessary for membrane fusion. Thus, these results indicate that CCR5-derived AHB peptides could provide a useful tool to define the mechanism(s) of HIV infection, and may provide insight which will contribute to the development of an anti-HIV-1 reagent

Structure-function characterization and optimization of a plant-derived antibacterial peptide.

Science.gov (United States)

Suarez, Mougli; Haenni, Marisa; Canarelli, Stéphane; Fisch, Florian; Chodanowski, Pierre; Servis, Catherine; Michielin, Olivier; Freitag, Ruth; Moreillon, Philippe; Mermod, Nicolas

2005-09-01

Crushed seeds of the Moringa oleifera tree have been used traditionally as natural flocculants to clarify drinking water. We previously showed that one of the seed peptides mediates both the sedimentation of suspended particles such as bacterial cells and a direct bactericidal activity, raising the possibility that the two activities might be related. In this study, the conformational modeling of the peptide was coupled to a functional analysis of synthetic derivatives. This indicated that partly overlapping structural determinants mediate the sedimentation and antibacterial activities. Sedimentation requires a positively charged, glutamine-rich portion of the peptide that aggregates bacterial cells. The bactericidal activity was localized to a sequence prone to form a helix-loop-helix structural motif. Amino acid substitution showed that the bactericidal activity requires hydrophobic proline residues within the protruding loop. Vital dye staining indicated that treatment with peptides containing this motif results in bacterial membrane damage. Assembly of multiple copies of this structural motif into a branched peptide enhanced antibacterial activity, since low concentrations effectively kill bacteria such as Pseudomonas aeruginosa and Streptococcus pyogenes without displaying a toxic effect on human red blood cells. This study thus identifies a synthetic peptide with potent antibacterial activity against specific human pathogens. It also suggests partly distinct molecular mechanisms for each activity. Sedimentation may result from coupled flocculation and coagulation effects, while the bactericidal activity would require bacterial membrane destabilization by a hydrophobic loop.

The optimization of peptide cargo bound to MHC class I molecules by the peptide-loading complex.

Science.gov (United States)

Elliott, Tim; Williams, Anthony

2005-10-01

Major histocompatibility complex (MHC) class I complexes present peptides from both self and foreign intracellular proteins on the surface of most nucleated cells. The assembled heterotrimeric complexes consist of a polymorphic glycosylated heavy chain, non-polymorphic beta(2) microglobulin, and a peptide of typically nine amino acids in length. Assembly of the class I complexes occurs in the endoplasmic reticulum and is assisted by a number of chaperone molecules. A multimolecular unit termed the peptide-loading complex (PLC) is integral to this process. The PLC contains a peptide transporter (transporter associated with antigen processing), a thiooxido-reductase (ERp57), a glycoprotein chaperone (calreticulin), and tapasin, a class I-specific chaperone. We suggest that class I assembly involves a process of optimization where the peptide cargo of the complex is edited by the PLC. Furthermore, this selective peptide loading is biased toward peptides that have a longer off-rate from the assembled complex. We suggest that tapasin is the key chaperone that directs this action of the PLC with secondary contributions from calreticulin and possibly ERp57. We provide a framework model for how this may operate at the molecular level and draw parallels with the proposed mechanism of action of human leukocyte antigen-DM for MHC class II complex optimization.

HLA-A*0201 T-cell epitopes in severe acute respiratory syndrome (SARS) coronavirus nucleocapsid and spike proteins

International Nuclear Information System (INIS)

Tsao, Y.-P.; Lin, J.-Y.; Jan, J.-T.; Leng, C.-H.; Chu, C.-C.; Yang, Y.-C.; Chen, S.-L.

2006-01-01

The immunogenicity of HLA-A*0201-restricted cytotoxic T lymphocyte (CTL) peptide in severe acute respiratory syndrome coronavirus (SARS-CoV) nuclear capsid (N) and spike (S) proteins was determined by testing the proteins' ability to elicit a specific cellular immune response after immunization of HLA-A2.1 transgenic mice and in vitro vaccination of HLA-A2.1 positive human peripheral blood mononuclearcytes (PBMCs). First, we screened SARS N and S amino acid sequences for allele-specific motif matching those in human HLA-A2.1 MHC-I molecules. From HLA peptide binding predictions (http://thr.cit.nih.gov/molbio/hla_bind/), ten each potential N- and S-specific HLA-A2.1-binding peptides were synthesized. The high affinity HLA-A2.1 peptides were validated by T2-cell stabilization assays, with immunogenicity assays revealing peptides N223-231, N227-235, and N317-325 to be First identified HLA-A*0201-restricted CTL epitopes of SARS-CoV N protein. In addition, previous reports identified three HLA-A*0201-restricted CTL epitopes of S protein (S978-986, S1203-1211, and S1167-1175), here we found two novel peptides S787-795 and S1042-1050 as S-specific CTL epitopes. Moreover, our identified N317-325 and S1042-1050 CTL epitopes could induce recall responses when IFN-γ stimulation of blood CD8 + T-cells revealed significant difference between normal healthy donors and SARS-recovered patients after those PBMCs were in vitro vaccinated with their cognate antigen. Our results would provide a new insight into the development of therapeutic vaccine in SARS

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.

Structural and pharmacological characteristics of chimeric peptides derived from peptide E and beta-endorphin reveal the crucial role of the C-terminal YGGFL and YKKGE motifs in their analgesic properties.

Science.gov (United States)

Condamine, Eric; Courchay, Karine; Rego, Jean-Claude Do; Leprince, Jérôme; Mayer, Catherine; Davoust, Daniel; Costentin, Jean; Vaudry, Hubert

2010-05-01

Peptide E (a 25-amino acid peptide derived from proenkephalin A) and beta-endorphin (a 31-amino acid peptide derived from proopiomelanocortin) bind with high affinity to opioid receptors and share structural similarities but induce analgesic effects of very different intensity. Indeed, whereas they possess the same N-terminus Met-enkephalin message sequence linked to a helix by a flexible spacer and a C-terminal part in random coil conformation, in contrast with peptide E, beta-endorphin produces a profound analgesia. To determine the key structural elements explaining this very divergent opioid activity, we have compared the structural and pharmacological characteristics of several chimeric peptides derived from peptide E and beta-endorphin. Structures were obtained under the same experimental conditions using circular dichroism, computational estimation of helical content and/or nuclear magnetic resonance spectroscopy (NMR) and NMR-restrained molecular modeling. The hot-plate and writhing tests were used in mice to evaluate the antinociceptive effects of the peptides. Our results indicate that neither the length nor the physicochemical profile of the spacer plays a fundamental role in analgesia. On the other hand, while the functional importance of the helix cannot be excluded, the last 5 residues in the C-terminal part seem to be crucial for the expression or absence of the analgesic activity of these peptides. These data raise the question of the true function of peptides E in opioidergic systems. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Antimicrobial Peptides Derived from Fusion Peptides of Influenza A Viruses, a Promising Approach to Designing Potent Antimicrobial Agents.

Science.gov (United States)

Wang, Jingyu; Zhong, Wenjing; Lin, Dongguo; Xia, Fan; Wu, Wenjiao; Zhang, Heyuan; Lv, Lin; Liu, Shuwen; He, Jian

2015-10-01

The emergence and dissemination of antibiotic-resistant bacterial pathogens have spurred the urgent need to develop novel antimicrobial agents with different mode of action. In this respect, we turned several fusogenic peptides (FPs) derived from the hemagglutinin glycoproteins (HAs) of IAV into potent antibacterials by replacing the negatively or neutrally charged residues of FPs with positively charged lysines. Their antibacterial activities were evaluated by testing the MICs against a panel of bacterial strains including S. aureus, S. mutans, P. aeruginosa, and E. coli. The results showed that peptides HA-FP-1, HA-FP-2-1, and HA-FP-3-1 were effective against both Gram-positive and Gram-negative bacteria with MICs ranging from 1.9 to 16.0 μm, while the toxicities toward mammalian cells were low. In addition, the mode of action and the secondary structure of these peptides were also discussed. These data not only provide several potent peptides displaying promising potential in development as broad antimicrobial agents, but also present a useful strategy in designing new antimicrobial agents. © 2015 John Wiley & Sons A/S.

Processing of pro-opiomelanocortin-derived amidated joining peptide and glycine-extended precursor in monkey pituitary

DEFF Research Database (Denmark)

Fenger, M

1991-01-01

The molecular forms of proopiomelanocortin (POMC) derived amidated and C-terminal glycine-extended joining peptide from monkey (Macaca mulatta) pituitary were determined. The predominant forms of joining peptide found were the low molecular peptides POMC(76-105) and POMC(76-106), respectively...... sequence of monkey and human POMC extremely conserved, but also the processing patterns are similar. The monkey therefore serves as a suitable model for studying regulation of the processing of POMC and the hypothalamus-pituitary-adrenal axis in man....

Monitoring multiple myeloma by idiotype-specific peptide binders of tumor-derived exosomes.

Science.gov (United States)

Iaccino, Enrico; Mimmi, Selena; Dattilo, Vincenzo; Marino, Fabiola; Candeloro, Patrizio; Di Loria, Antonio; Marimpietri, Danilo; Pisano, Antonio; Albano, Francesco; Vecchio, Eleonora; Ceglia, Simona; Golino, Gaetanina; Lupia, Antonio; Fiume, Giuseppe; Quinto, Ileana; Scala, Giuseppe

2017-10-13

Tumor-derived exosomes (TDEs) play a pivotal role in tumor establishment and progression, and are emerging biomarkers for tumor diagnosis in personalized medicine. To date, there is a lack of efficient technology platforms for exosome isolation and characterization. Multiple myeloma (MM) is an incurable B-cell malignancy due to the rapid development of drug-resistance. MM-released exosomes express the immunoglobulin B-cell receptor (Ig-BCR) of the tumor B-cells, which can be targeted by Idiotype-binding peptides (Id-peptides). In this study, we analyzed the production of MM-released exosomes in the murine 5T33MM multiple myeloma model as biomarkers of tumor growth. To this end, we selected Id-peptides by screening a phage display library using as bait the Ig-BCR expressed by 5T33MM cells. By FACS, the FITC-conjugated Id-peptides detected the MM-released exosomes in the serum of 5T33MM-engrafted mice, levels of which are correlated with tumor progression at an earlier time point compared to serum paraprotein. These results indicate that Id-peptide-based recognition of MM-released exosomes may represent a very sensitive diagnostic approach for clinical evaluation of disease progression.

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

Tumor imaging and targeting potential of an Hsp70-derived 14-mer peptide.

Directory of Open Access Journals (Sweden)

Mathias Gehrmann

Full Text Available We have previously used a unique mouse monoclonal antibody cmHsp70.1 to demonstrate the selective presence of a membrane-bound form of Hsp70 (memHsp70 on a variety of leukemia cells and on single cell suspensions derived from solid tumors of different entities, but not on non-transformed cells or cells from corresponding 'healthy' tissue. This antibody can be used to image tumors in vivo and target them for antibody-dependent cellular cytotoxicity. Tumor-specific expression of memHsp70 therefore has the potential to be exploited for theranostic purposes. Given the advantages of peptides as imaging and targeting agents, this study assessed whether a 14-mer tumor penetrating peptide (TPP; TKDNNLLGRFELSG, the sequence of which is derived from the oligomerization domain of Hsp70 which is expressed on the cell surface of tumor cells, can also be used for targeting membrane Hsp70 positive (memHsp70+ tumor cells, in vitro.The specificity of carboxy-fluorescein (CF- labeled TPP (TPP to Hsp70 was proven in an Hsp70 knockout mammary tumor cell system. TPP specifically binds to different memHsp70+ mouse and human tumor cell lines and is rapidly taken up via endosomes. Two to four-fold higher levels of CF-labeled TPP were detected in MCF7 (82% memHsp70+ and MDA-MB-231 (75% memHsp70+ cells compared to T47D cells (29% memHsp70+ that exhibit a lower Hsp70 membrane positivity. After 90 min incubation, TPP co-localized with mitochondrial membranes in memHsp70+ tumors. Although there was no evidence that any given vesicle population was specifically localized, fluorophore-labeled cmHsp70.1 antibody and TPP preferentially accumulated in the proximity of the adherent surface of cultured cells. These findings suggest a potential association between membrane Hsp70 expression and cytoskeletal elements that are involved in adherence, the establishment of intercellular synapses and/or membrane reorganization.This study demonstrates the specific binding and rapid

Antiinflammatory properties of a peptide derived from interleukin-4

DEFF Research Database (Denmark)

Klementiev, Boris; Enevoldsen, Maj N; Li, Shizhong

2013-01-01

Interleukin-4 (IL-4) is a potent antiinflammatory cytokine. However its use in the clinic is hampered by side effects. We here describe the identification of a novel synthetic peptide, termed Ph8, derived from α-helix C of IL-4, which interacts with IL-4 receptor α (IL-4Rα). Employing various...... and reduced acute inflammation in carrageenan-induced edema. Our findings indicate that Ph8 is a promising potential drug candidate for the treatment of inflammatory diseases....

Evaluation of protective efficacy of the synthetic peptide vaccine containing the T-helper 1 epitope with CpG oligodeoxynucleotide against feline infectious peritonitis virus infection in cats.

Science.gov (United States)

Takano, Tomomi; Tomizawa, Keisuke; Morioka, Hiroyuki; Doki, Tomoyoshi; Hohdatsu, Tsutomu

2014-01-01

Feline infectious peritonitis (FIP) is a feline coronavirus-induced fatal disease in domestic and wild cats. Cellular immunity is considered to play an important role in the prevention of FIP. Thus, induction of the cellular immune response is essential in vaccines against FIP virus (FIPV) infection. We immunized cats with peptides containing T-helper (Th)1 epitopes derived from the nucleocapsid (N) protein of the type I FIPV KU-2 strain (NP7 and NP8) with feline CpG-oligodeoxynucleotides (fCpG-ODNs) as a vaccine adjuvant. Prevention against type II FIPV 79-1146 strain-induced FIP was slightly better in specific pathogen-free cats treated with NP7 and NP8 with fCpG-ODNs. However, immune tolerance was suggested to be induced by the high dose and frequency of NP7 and NP8 with fCpG-ODNs. Further investigations on the combination and concentrations of the peptides and fCpG-ODNs, dose, frequency and route of administration are needed.

New dendrimer - Peptide host - Guest complexes: Towards dendrimers as peptide carriers

DEFF Research Database (Denmark)

Boas, Ulrik; Sontjens, S.H.M.; Jensen, Knud Jørgen

2002-01-01

Adamantyl urea and adamantyl thiourea modified poly(propylene imine) dendrimers act as hosts for N-terminal tert-butoxycarbonyl (Boc)-protected peptides and form chloroform-soluble complexes. investigations with NMR spectroscopy show that the peptide is bound to the dendrimer by ionic interactions...... between the dendrimer outer shell tertiary amines and the C-terminal carboxylic acid of the peptide, and also through host-urea to peptide-amide hydrogen bonding. The hydrogen-bonding nature of the peptide dendrimer interactions was further confirmed by using Fourier transform IR spectroscopy, for which...... the NH- and CO-stretch signals of the peptide amide moieties shift towards lower wave-numbers upon complexation with the dendrimer. Spatial analysis of the complexes with NOESY spectroscopy generally shows close proximity of the N-terminal Boc group of the peptide to the peripheral adamantyl groups...

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

Dual function of a bee (Apis cerana) inhibitor cysteine knot peptide that acts as an antifungal peptide and insecticidal venom toxin.

Science.gov (United States)

Park, Hee Geun; Kyung, Seung Su; Lee, Kwang Sik; Kim, Bo Yeon; Choi, Yong Soo; Yoon, Hyung Joo; Kwon, Hyung Wook; Je, Yeon Ho; Jin, Byung Rae

2014-12-01

Inhibitor cysteine knot (ICK) peptides exhibit ion channel blocking, insecticidal, and antimicrobial activities, but currently, no functional roles for bee-derived ICK peptides have been identified. In this study, a bee (Apis cerana) ICK peptide (AcICK) that acts as an antifungal peptide and as an insecticidal venom toxin was identified. AcICK contains an ICK fold that is expressed in the epidermis, fat body, or venom gland and is present as a 6.6-kDa peptide in bee venom. Recombinant AcICK peptide (expressed in baculovirus-infected insect cells) bound directly to Beauveria bassiana and Fusarium graminearum, but not to Escherichia coli or Bacillus thuringiensis. Consistent with these findings, AcICK showed antifungal activity, indicating that AcICK acts as an antifungal peptide. Furthermore, AcICK expression is induced in the fat body and epidermis after injection with B. bassiana. These results provide insight into the role of AcICK during the innate immune response following fungal infection. Additionally, we show that AcICK has insecticidal activity. Our results demonstrate a functional role for AcICK in bees: AcICK acts as an antifungal peptide in innate immune reactions in the body and as an insecticidal toxin in venom. The finding that the AcICK peptide functions with different mechanisms of action in the body and in venom highlights the two-pronged strategy that is possible with the bee ICK peptide. Copyright © 2014 Elsevier Ltd. All rights reserved.

Solid-Phase Reactions of Iminium Ions: Cyclized Peptide Derivatives

DEFF Research Database (Denmark)

Wang, Yuanyuan

formation of N,N’-aminals by nucleophilic attack of the peptide backbone is reversible under strongly acidic conditions and the N,N’-aminal is likely to be the kinetic product of many INCIC reactions. In addition, the N,N’-aminals are stable in the absence of acid but could be converted to the THIQ...... derivatives in solution phase under acid conditions in the presence of an active C-nucleophile in the side chain. The high yielding nature of the aminal formation is confirmed by solution phase synthesis. The introduced azide and alkyne residues in the side chain of N,N’-aminal products were further......BB may undergo auto-oxidation to quinazoline-2,4-diones in the absence of a suitable nucleophile on the side chain or backbone of the peptide (Chapter 4). The structure is confirmed by comparison with products obtained from solution-phase synthesis under the same conditions, one of which was confirmed...

Detection of Coronaviruses in Bats of Various Species in Italy

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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.

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

Antimicrobial efficacy of granulysin-derived synthetic peptides in acne vulgaris.

Science.gov (United States)

Lim, Hee-Sun; Chun, Seung-Min; Soung, Min-Gyu; Kim, Jenny; Kim, Seong-Jin

2015-07-01

Antimicrobial peptides are considered as a potential alternative to antibiotic treatment in acne vulgaris because the development of a resistant strain of Propionibacterium acnes is problematic. Granulysin can be regarded as an ideal substance with which to treat acne because it has antimicrobial and anti-inflammatory effects. This study was performed to explore the effectiveness of granulysin-derived peptides (GDPs) in killing P. acnes in vitro under a standard microbiologic assay and to evaluate their potential use in a topical agent for the treatment of acne vulgaris. Twenty different peptides based on the known sequence of a GDP were synthesized and tested in vitro for antimicrobial activity. Thirty patients with facial acne vulgaris were instructed to apply a topical formulation containing synthetic GDP to acne lesions twice per day for 12 weeks. A newly synthesized peptide in which aspartic acid was substituted with arginine, and methionine was substituted with cysteine, showed the highest antimicrobial activity against P. acnes. Moreover, it was effective against both Gram-positive and Gram-negative bacteria in vitro. After treatment with the topical formulation containing 50 ppm of synthetic peptide for 12 weeks, a significant reduction in the number of pustules was observed, regardless of the increase in the number of comedones. In addition, a significant reduction in the clinical grade of acne based on the Korean Acne Grading System (KAGS) was evident. Synthesized GDP shows strong antimicrobial activity against P. acnes in vitro. The clinical improvement observed suggests a topical formulation containing the GDP has therapeutic potential for the improvement of inflammatory-type acne vulgaris by its antimicrobial activity. © 2015 The International Society of Dermatology.

Screening of soy protein-derived hypotriglyceridemic di-peptides in vitro and in vivo

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Matsui Toshiro

2011-05-01

Full Text Available Abstract Background Soy protein and soy peptides have attracted considerable attention because of their potentially beneficial biological properties, including antihypertensive, anticarcinogenic, and hypolipidemic effects. Although soy protein isolate contains several bioactive peptides that have distinct physiological activities in lipid metabolism, it is not clear which peptide sequences are responsible for the triglyceride (TG-lowering effects. In the present study, we investigated the effects of soy protein-derived peptides on lipid metabolism, especially TG metabolism, in HepG2 cells and obese Otsuka Long-Evans Tokushima fatty (OLETF rats. Results In the first experiment, we found that soy crude peptide (SCP-LD3, which was prepared by hydrolyze of soy protein isolate with endo-type protease, showed hypolipidemic effects in HepG2 cells and OLETF rats. In the second experiment, we found that hydrophilic fraction, separated from SCP-LD3 with hydrophobic synthetic absorbent, revealed lipid-lowering effects in HepG2 cells and OLETF rats. In the third experiment, we found that Fraction-C (Frc-C peptides, fractionated from hydrophilic peptides by gel permeation chromatography-high performance liquid chromatography, significantly reduced TG synthesis and apolipoprotein B (apoB secretion in HepG2 cells. In the fourth experiment, we found that the fraction with 0.1% trifluoroacetic acid, isolated from Frc-C peptides by octadecylsilyl column chromatography, showed hypolipidemic effects in HepG2 cells. In the final experiment, we found that 3 di-peptides, Lys-Ala, Val-Lys, and Ser-Tyr, reduced TG synthesis, and Ser-Tyr additionally reduced apoB secretion in HepG2 cells. Conclusion Novel active peptides with TG-lowering effects from soy protein have been isolated.

Suppression of gastric cancer dissemination by ephrin-B1-derived peptide.

Science.gov (United States)

Tanaka, Masamitsu; Kamata, Reiko; Yanagihara, Kazuyoshi; Sakai, Ryuichi

2010-01-01

Interaction of the Eph family of receptor protein tyrosine kinases and their ligands, ephrin family members, induces bidirectional signaling through cell-cell contacts. High expression of B-type ephrin is associated with high invasion potential of tumors, and we previously observed that signaling through the C-terminus of ephrin-B1 mediates the migration and invasion of cells, and is involved in the promotion of carcinomatous peritonitis in vivo. Here we show that the intracellular introduction of a synthetic peptide derived from ephrin-B1 C-terminus blocks ephrin-B1 mediated signaling in scirrhous gastric cancer cells. Treatment of cancer cells with a fusion peptide consisting of HIV-TAT and amino acids 331-346 of ephrin-B1 (PTD-EFNB1-C) suppressed the activation of RhoA, mediated by the association of ephrin-B1 with an adaptor protein Dishevelled, and also inhibited extracellular secretion of metalloproteinase. Moreover, injection of PTD-EFNB1-C peptide into the peritoneal cavity of nude mice suppressed carcinomatous peritonitis of intraperitoneally transplanted scirrhous gastric cancer cells. These results indicate the possible application of ephrin-B1 C-terminal peptide to develop novel protein therapy for scirrhous gastric carcinoma, especially in the stage of tumor progression, including peritoneal dissemination.

Effects of lactoferrin derived peptides on simulants of biological warfare agents.

Science.gov (United States)

Sijbrandij, Tjitske; Ligtenberg, Antoon J; Nazmi, Kamran; Veerman, Enno C I; Bolscher, Jan G M; Bikker, Floris J

2017-01-01

Lactoferrin (LF) is an important immune protein in neutrophils and secretory fluids of mammals. Bovine LF (bLF) harbours two antimicrobial stretches, lactoferricin and lactoferampin, situated in close proximity in the N1 domain. To mimic these antimicrobial domain parts a chimeric peptide (LFchimera) has been constructed comprising parts of both stretches (LFcin17-30 and LFampin265-284). To investigate the potency of this construct to combat a set of Gram positive and Gram negative bacteria which are regarded as simulants for biological warfare agents, the effect on bacterial killing, membrane permeability and membrane polarity were determined in comparison to the constituent peptides and the native bLF. Furthermore we aimed to increase the antimicrobial potency of the bLF derived peptides by cationic amino acid substitutions. Overall, the bactericidal activity of the peptides could be related to membrane disturbing effects, i.e. membrane permeabilization and depolarization. Those effects were most prominent for the LFchimera. Arginine residues were found to be crucial for displaying antimicrobial activity, as lysine to arginine substitutions resulted in an increased antimicrobial activity, affecting mostly LFampin265-284 whereas arginine to lysine substitutions resulted in a decreased bactericidal activity, predominantly in case of LFcin17-30.

The TFPI-2 derived peptide EDC34 improves outcome of gram-negative sepsis.

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Praveen Papareddy

Full Text Available Sepsis is characterized by a dysregulated host-pathogen response, leading to high cytokine levels, excessive coagulation and failure to eradicate invasive bacteria. Novel therapeutic strategies that address crucial pathogenetic steps during infection are urgently needed. Here, we describe novel bioactive roles and therapeutic anti-infective potential of the peptide EDC34, derived from the C-terminus of tissue factor pathway inhibitor-2 (TFPI-2. This peptide exerted direct bactericidal effects and boosted activation of the classical complement pathway including formation of antimicrobial C3a, but inhibited bacteria-induced activation of the contact system. Correspondingly, in mouse models of severe Escherichia coli and Pseudomonas aeruginosa infection, treatment with EDC34 reduced bacterial levels and lung damage. In combination with the antibiotic ceftazidime, the peptide significantly prolonged survival and reduced mortality in mice. The peptide's boosting effect on bacterial clearance paired with its inhibiting effect on excessive coagulation makes it a promising therapeutic candidate for invasive Gram-negative infections.

The TFPI-2 derived peptide EDC34 improves outcome of gram-negative sepsis.

Science.gov (United States)

Papareddy, Praveen; Kalle, Martina; Sørensen, Ole E; Malmsten, Martin; Mörgelin, Matthias; Schmidtchen, Artur

2013-01-01

Sepsis is characterized by a dysregulated host-pathogen response, leading to high cytokine levels, excessive coagulation and failure to eradicate invasive bacteria. Novel therapeutic strategies that address crucial pathogenetic steps during infection are urgently needed. Here, we describe novel bioactive roles and therapeutic anti-infective potential of the peptide EDC34, derived from the C-terminus of tissue factor pathway inhibitor-2 (TFPI-2). This peptide exerted direct bactericidal effects and boosted activation of the classical complement pathway including formation of antimicrobial C3a, but inhibited bacteria-induced activation of the contact system. Correspondingly, in mouse models of severe Escherichia coli and Pseudomonas aeruginosa infection, treatment with EDC34 reduced bacterial levels and lung damage. In combination with the antibiotic ceftazidime, the peptide significantly prolonged survival and reduced mortality in mice. The peptide's boosting effect on bacterial clearance paired with its inhibiting effect on excessive coagulation makes it a promising therapeutic candidate for invasive Gram-negative infections.

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

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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.

Neutrophil elastase and elastin-derived peptides in BAL fluid and emphysematous changes on CT scans

International Nuclear Information System (INIS)

Betsuyaku, Tomoko; Nishimura, Masaharu; Yoshioka, Aya; Takeyabu, Kimihiro; Miyamoto, Kenji; Kawakami, Yoshikazu

1996-01-01

We examined the relationship between neutrophil elastase, elastin-derived peptides in bronchoalveolar lavage (BAL) fluid, and the development of pulmonary emphysema. The level of neutrophil elastase was higher in asymptomatic current smokers with emphysematous changes on computed tomographic scans than in current smokers without emphysematous changes, and was found to be correlated with the level of elastin-derived peptides in BAL fluid. Subjects with high levels of neutrophil elastase in BAL fluid had faster annual declines in FEV 1 . We conclude that the level of neutrophil elastase in BAL fluid can be used to differentiate asymptomatic cigarette smokers who are at risk for pulmonary emphysema from those who are not. (author)

Venom-derived peptides inhibiting Kir channels: Past, present, and future.

Science.gov (United States)

Doupnik, Craig A

2017-12-01

Inwardly rectifying K + (Kir) channels play a significant role in vertebrate and invertebrate biology by regulating the movement of K + ions involved in membrane transport and excitability. Yet unlike other ion channels including their ancestral K + -selective homologs, there are very few venom toxins known to target and inhibit Kir channels with the potency and selectivity found for the Ca 2+ -activated and voltage-gated K + channel families. It is unclear whether this is simply due to a lack of discovery, or instead a consequence of the evolutionary processes that drive the development of venom components towards their targets based on a collective efficacy to 1) elicit pain for defensive purposes, 2) promote paralysis for prey capture, or 3) facilitate delivery of venom components into the circulation. The past two decades of venom screening has yielded three venom peptides with inhibitory activity towards mammalian Kir channels, including the discovery of tertiapin, a high-affinity pore blocker from the venom of the European honey bee Apis mellifera. Venomics and structure-based computational approaches represent exciting new frontiers for venom peptide development, where re-engineering peptide 'scaffolds' such as tertiapin may aid in the quest to expand the palette of potent and selective Kir channel blockers for future research and potentially new therapeutics. This article is part of the Special Issue entitled 'Venom-derived Peptides as Pharmacological Tools.' Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

[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.

Enhancement of endotoxin neutralization by coupling of a C12-alkyl chain to a lactoferricin-derived peptide

Science.gov (United States)

2004-01-01

Antibacterial peptide acylation, which mimics the structure of the natural lipopeptide polymyxin B, increases antimicrobial and endotoxin-neutralizing activities. The interaction of the lactoferricin-derived peptide LF11 and its N-terminally acylated analogue, lauryl-LF11, with different chemotypes of bacterial lipopolysaccharide (LPS Re, Ra and smooth S form) was investigated by biophysical means and was related to the peptides' biological activities. Both peptides exhibit high antibacterial activity against the three strains of Salmonella enterica differing in the LPS chemotype. Lauryl-LF11 has one order of magnitude higher activity against Re-type, but activity against Ra- and S-type bacteria is comparable with that of LF11. The alkyl derivative peptide lauryl-LF11 shows a much stronger inhibition of the LPS-induced cytokine induction in human mononuclear cells than LF11. Although peptide–LPS interaction is essentially of electrostatic nature, the lauryl-modified peptide displays a strong hydrophobic component. Such a feature might then explain the fact that saturation of the peptide binding takes place at a much lower peptide/LPS ratio for LF11 than for lauryl-LF11, and that an overcompensation of the negative LPS backbone charges is observed for lauryl-LF11. The influence of LF11 on the gel-to-liquid-crystalline phase-transition of LPS is negligible for LPS Re, but clearly fluidizing for LPS Ra. In contrast, lauryl-LF11 causes a cholesterol-like effect in the two chemotypes, fluidizing in the gel and rigidifying of the hydrocarbon chains in the liquid-crystalline phase. Both peptides convert the mixed unilamellar/non-lamellar aggregate structure of lipid A, the ‘endotoxic principle’ of LPS, into a multilamellar one. These data contribute to the understanding of the mechanisms of the peptide-mediated neutralization of endotoxin and effect of lipid modification of peptides. PMID:15344905

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.

Synthesis and characterization of new chiral ketopinic acid-derived catalysts immobilized on polystyrene-bound imidazole

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Hassan Yusuf

2017-02-01

Full Text Available Four new chiral ketopinic acid-derived catalysts were anchored on a polystyrene-bound imidazole via non-covalent bond. The resulting heterogeneous catalysts were successfully characterized using IR, SEM, and TGA analyses.

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

Proteolytic signatures define unique thrombin-derived peptides present in human wound fluid in vivo.

Science.gov (United States)

Saravanan, Rathi; Adav, Sunil S; Choong, Yeu Khai; van der Plas, Mariena J A; Petrlova, Jitka; Kjellström, Sven; Sze, Siu Kwan; Schmidtchen, Artur

2017-10-13

The disease burden of failing skin repair and non-healing ulcers is extensive. There is an unmet need for new diagnostic approaches to better predict healing activity and wound infection. Uncontrolled and excessive protease activity, of endogenous or bacterial origin, has been described as a major contributor to wound healing impairments. Proteolytic peptide patterns could therefore correlate and "report" healing activity and infection. This work describes a proof of principle delineating a strategy by which peptides from a selected protein, human thrombin, are detected and attributed to proteolytic actions. With a particular focus on thrombin-derived C-terminal peptides (TCP), we show that distinct peptide patterns are generated in vitro by the human S1 peptidases human neutrophil elastase and cathepsin G, and the bacterial M4 peptidases Pseudomonas aeruginosa elastase and Staphylococcus aureus aureolysin, respectively. Corresponding peptide sequences were identified in wound fluids from acute and non-healing ulcers, and notably, one peptide, FYT21 (FYTHVFRLKKWIQKVIDQFGE), was only present in wound fluid from non-healing ulcers colonized by P. aeruginosa and S. aureus. Our result is a proof of principle pointing at the possibility of defining peptide biomarkers reporting distinct proteolytic activities, of potential implication for improved diagnosis of wound healing and infection.

Antibacterial activity of synthetic peptides derived from lactoferricin against Escherichia coli ATCC 25922 and Enterococcus faecalis ATCC 29212.

Science.gov (United States)

León-Calvijo, María A; Leal-Castro, Aura L; Almanzar-Reina, Giovanni A; Rosas-Pérez, Jaiver E; García-Castañeda, Javier E; Rivera-Monroy, Zuly J

2015-01-01

Peptides derived from human and bovine lactoferricin were designed, synthesized, purified, and characterized using RP-HPLC and MALDI-TOF-MS. Specific changes in the sequences were designed as (i) the incorporation of unnatural amino acids in the sequence, the (ii) reduction or (iii) elongation of the peptide chain length, and (iv) synthesis of molecules with different number of branches containing the same sequence. For each peptide, the antibacterial activity against Escherichia coli ATCC 25922 and Enterococcus faecalis ATCC 29212 was evaluated. Our results showed that Peptides I.2 (RWQWRWQWR) and I.4 ((RRWQWR)4K2Ahx2C2) exhibit bigger or similar activity against E. coli (MIC 4-33 μM) and E. faecalis (MIC 10-33 μM) when they were compared with lactoferricin protein (LF) and some of its derivate peptides as II.1 (FKCRRWQWRMKKLGA) and IV.1 (FKCRRWQWRMKKLGAPSITCVRRAE). It should be pointed out that Peptides I.2 and I.4, containing the RWQWR motif, are short and easy to synthesize; our results demonstrate that it is possible to design and obtain synthetic peptides that exhibit enhanced antibacterial activity using a methodology that is fast and low-cost and that allows obtaining products with a high degree of purity and high yield.

Antibacterial Activity of Synthetic Peptides Derived from Lactoferricin against Escherichia coli ATCC 25922 and Enterococcus faecalis ATCC 29212

Directory of Open Access Journals (Sweden)

María A. León-Calvijo

2015-01-01

Full Text Available Peptides derived from human and bovine lactoferricin were designed, synthesized, purified, and characterized using RP-HPLC and MALDI-TOF-MS. Specific changes in the sequences were designed as (i the incorporation of unnatural amino acids in the sequence, the (ii reduction or (iii elongation of the peptide chain length, and (iv synthesis of molecules with different number of branches containing the same sequence. For each peptide, the antibacterial activity against Escherichia coli ATCC 25922 and Enterococcus faecalis ATCC 29212 was evaluated. Our results showed that Peptides I.2 (RWQWRWQWR and I.4 ((RRWQWR4K2Ahx2C2 exhibit bigger or similar activity against E. coli (MIC 4–33 μM and E. faecalis (MIC 10–33 μM when they were compared with lactoferricin protein (LF and some of its derivate peptides as II.1 (FKCRRWQWRMKKLGA and IV.1 (FKCRRWQWRMKKLGAPSITCVRRAE. It should be pointed out that Peptides I.2 and I.4, containing the RWQWR motif, are short and easy to synthesize; our results demonstrate that it is possible to design and obtain synthetic peptides that exhibit enhanced antibacterial activity using a methodology that is fast and low-cost and that allows obtaining products with a high degree of purity and high yield.

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...

The relation between major histocompatibility complex (MHC) restriction and the capacity of Ia to bind immunogenic peptides

DEFF Research Database (Denmark)

Buus, S; Sette, A; Colon, S M

1987-01-01

The capacity of purified I-Ad, I-Ed, I-Ak, and I-Ek to bind to protein derived peptides that have been previously reported to be T cell immunogens has been examined. For each of the 12 peptides studied strong binding to the relevant Ia restriction element was observed. All the peptides bound more...... than one Ia molecule; however, for 11 of 12 peptides, the dominant binding was to the restriction element, whereas in one instance the dominant binding was to a nonrestriction element. When the peptides were used to inhibit the presentation of antigen by prefixed accessory cells to T cells......, an excellent correlation was found between the capacity of a peptide to inhibit the binding of an antigen to purified Ia and the capacity of the peptide to inhibit accessory cell presentation of the antigen. Thus, the binding of peptide to purified Ia is immunologically relevant, and Ia seems to be the only...

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

Iodinated derivatives of vasoactive intestinal peptide (VIP), PHI and PHM: purification, chemical characterization and biological activity

International Nuclear Information System (INIS)

McMaster, D.; Suzuki, Y.; Rorstad, O.; Lederis, K.

1987-01-01

The iodination of vasoactive intestinal peptide (VIP) was studied, using a variety of enzymatic and chemical iodination methods. Reversed phase high performance liquid chromatography (HPLC) was used to purify the reaction products. The lactoperoxidase-glucose oxidase method gave excellent results in terms of reproducibility, iodine incorporation, and yield of the non-oxidized products [Tyr(I)10]VIP and [Tyr(I)22]VIP, and was used to prepare both 125 I and 127 I labelled derivatives. In both cases, direct application to HPLC and a single column system were used. Although the oxidized peptides [Tyr(I)10,Met(O)17]VIP and [Tyr(I)22,Met(O)17]VIP could be generated to varying degrees directly by iodination of VIP, these were most conveniently prepared by iodination of [Met(O)17]VIP. Iodinated derivatives of the homologous peptides PHI and PHM were likewise prepared by rapid, one-step HPLC procedures. The site and degree of iodination were determined by HPLC peptide mapping of tryptic digests and amino acid analyses, and in the case of [Tyr(I)10]VIP also by sequencing. The vasorelaxant activities of the iodinated peptides in bovine cerebral artery preparations did not differ significantly from those of the corresponding noniodinated peptides, with the exception of [Tyr(I)10,Met(O)17]VIP and [Tyr(I)22,Met(O)17]VIP which, unlike [Met(O)17]VIP itself, had slightly lower potency than VIP

Antimicrobial activity of synthetic cationic peptides and lipopeptides derived from human lactoferricin against Pseudomonas aeruginosa planktonic cultures and biofilms.

Science.gov (United States)

Sánchez-Gómez, Susana; Ferrer-Espada, Raquel; Stewart, Philip S; Pitts, Betsey; Lohner, Karl; Martínez de Tejada, Guillermo

2015-07-07

Infections by Pseudomonas aeruginosa constitute a serious health threat because this pathogen -particularly when it forms biofilms - can acquire resistance to the majority of conventional antibiotics. This study evaluated the antimicrobial activity of synthetic peptides based on LF11, an 11-mer peptide derived from human lactoferricin against P. aeruginosa planktonic and biofilm-forming cells. We included in this analysis selected N-acylated derivatives of the peptides to analyze the effect of acylation in antimicrobial activity. To assess the efficacy of compounds against planktonic bacteria, microdilution assays to determine the minimal inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and time-kill studies were conducted. The anti-biofilm activity of the agents was assessed on biofilms grown under static (on microplates) and dynamic (in a CDC-reactor) flow regimes. The antimicrobial activity of lipopeptides differed from that of non-acylated peptides in their killing mechanisms on planktonic and biofilm-forming cells. Thus, acylation enhanced the bactericidal activity of the parental peptides and resulted in lipopeptides that were uniformly bactericidal at their MIC. In contrast, acylation of the most potent anti-biofilm peptides resulted in compounds with lower anti-biofilm activity. Both peptides and lipopeptides displayed very rapid killing kinetics and all of them required less than 21 min to reduce 1,000 times the viability of planktonic cells when tested at 2 times their MBC. The peptides, LF11-215 (FWRIRIRR) and LF11-227 (FWRRFWRR), displayed the most potent anti-biofilm activity causing a 10,000 fold reduction in cell viability after 1 h of treatment at 10 times their MIC. At that concentration, these two compounds exhibited low citotoxicity on human cells. In addition to its bactericidal activity, LF11-227 removed more that 50 % of the biofilm mass in independent assays. Peptide LF11-215 and two of the shortest and least

Three-Dimensional Graphene–RGD Peptide Nanoisland Composites That Enhance the Osteogenesis of Human Adipose-Derived Mesenchymal Stem Cells

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Ee-Seul Kang

2018-02-01

Full Text Available Graphene derivatives have immense potential in stem cell research. Here, we report a three-dimensional graphene/arginine-glycine-aspartic acid (RGD peptide nanoisland composite effective in guiding the osteogenesis of human adipose-derived mesenchymal stem cells (ADSCs. Amine-modified silica nanoparticles (SiNPs were uniformly coated onto an indium tin oxide electrode (ITO, followed by graphene oxide (GO encapsulation and electrochemical deposition of gold nanoparticles. A RGD–MAP–C peptide, with a triple-branched repeating RGD sequence and a terminal cysteine, was self-assembled onto the gold nanoparticles, generating the final three-dimensional graphene–RGD peptide nanoisland composite. We generated substrates with various gold nanoparticle–RGD peptide cluster densities, and found that the platform with the maximal number of clusters was most suitable for ADSC adhesion and spreading. Remarkably, the same platform was also highly efficient at guiding ADSC osteogenesis compared with other substrates, based on gene expression (alkaline phosphatase (ALP, runt-related transcription factor 2, enzyme activity (ALP, and calcium deposition. ADSCs induced to differentiate into osteoblasts showed higher calcium accumulations after 14–21 days than when grown on typical GO-SiNP complexes, suggesting that the platform can accelerate ADSC osteoblastic differentiation. The results demonstrate that a three-dimensional graphene–RGD peptide nanoisland composite can efficiently derive osteoblasts from mesenchymal stem cells.

Competitive fitness in coronaviruses is not correlated with size or number of double-membrane vesicles under reduced-temperature growth conditions.

Science.gov (United States)

Al-Mulla, Hawaa M N; Turrell, Lauren; Smith, Nicola M; Payne, Luke; Baliji, Surendranath; Züst, Roland; Thiel, Volker; Baker, Susan C; Siddell, Stuart G; Neuman, Benjamin W

2014-04-01

Positive-stranded viruses synthesize their RNA in membrane-bound organelles, but it is not clear how this benefits the virus or the host. For coronaviruses, these organelles take the form of double-membrane vesicles (DMVs) interconnected by a convoluted membrane network. We used electron microscopy to identify murine coronaviruses with mutations in nsp3 and nsp14 that replicated normally while producing only half the normal amount of DMVs under low-temperature growth conditions. Viruses with mutations in nsp5 and nsp16 produced small DMVs but also replicated normally. Quantitative reverse transcriptase PCR (RT-PCR) confirmed that the most strongly affected of these, the nsp3 mutant, produced more viral RNA than wild-type virus. Competitive growth assays were carried out in both continuous and primary cells to better understand the contribution of DMVs to viral fitness. Surprisingly, several viruses that produced fewer or smaller DMVs showed a higher fitness than wild-type virus at the reduced temperature, suggesting that larger and more numerous DMVs do not necessarily confer a competitive advantage in primary or continuous cell culture. For the first time, this directly demonstrates that replication and organelle formation may be, at least in part, studied separately during infection with positive-stranded RNA virus. IMPORTANCE The viruses that cause severe acute respiratory syndrome (SARS), poliomyelitis, and hepatitis C all replicate in double-membrane vesicles (DMVs). The big question about DMVs is why they exist in the first place. In this study, we looked at thousands of infected cells and identified two coronavirus mutants that made half as many organelles as normal and two others that made typical numbers but smaller organelles. Despite differences in DMV size and number, all four mutants replicated as efficiently as wild-type virus. To better understand the relative importance of replicative organelles, we carried out competitive fitness experiments. None

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

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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.

Structural Basis for Degenerate Recognition of Natural HIV Peptide Variants by Cytotoxic Lymphocytes

International Nuclear Information System (INIS)

Martinez-Hackert, E.; Anikeeva, N.; Kalams, S.; Walker, B.; Hendrickson, W.; Sykulev, Y.

2006-01-01

It is well established that even small changes in amino acid side chains of antigenic peptide bound to MHC protein may completely abrogate recognition of the peptide-MHC (pMHC) complex by the T-cell receptor (TCR). Often, however, several non-conservative substitutions in the peptide antigen are accommodated and do not impair its recognition by TCR. For example, a preponderance of natural sequence variants of the HIV p17 Gag-derived peptide SLYNTVATL (SL9) are recognized by cytotoxic T lymphocytes (CTL), which implies that interactions with SL9 variants are degenerate both with respect to the class I MHC molecule and with respect to TCR. Here we study the molecular basis for this degenerate recognition of SL9 variants. We show that several SL9 variants bind comparably well to soluble HLA-A2 and to a particular soluble TCR and that these variants are active in the cognate cytotoxicity assay. Natural SL9 variation is restricted by its context in the HIV p17 matrix protein, and we have used synthetic variants to explore the wider spectrum of recognition. High-resolution crystal structures of seven selected SL9 variants bound to HLA-A2 all have remarkably similar peptide conformations and side-chain dispositions outside sites of substitution. This preservation of the peptide conformation despite epitope variations suggests a mechanism for the observed degeneracy in pMHC recognition by TCR, and may contribute to the persistence of SL9-mediated immune responses in chronically infected individuals

Constitutive expression of transgenes encoding derivatives of the synthetic antimicrobial peptide BP100: impact on rice host plant fitness

Directory of Open Access Journals (Sweden)

Nadal Anna

2012-09-01

Full Text Available Abstract Background The Biopeptide BP100 is a synthetic and strongly cationic α-helical undecapeptide with high, specific antibacterial activity against economically important plant-pathogenic bacteria, and very low toxicity. It was selected from a library of synthetic peptides, along with other peptides with activities against relevant bacterial and fungal species. Expression of the BP100 series of peptides in plants is of major interest to establish disease-resistant plants and facilitate molecular farming. Specific challenges were the small length, peptide degradation by plant proteases and toxicity to the host plant. Here we approached the expression of the BP100 peptide series in plants using BP100 as a proof-of-concept. Results Our design considered up to three tandemly arranged BP100 units and peptide accumulation in the endoplasmic reticulum (ER, analyzing five BP100 derivatives. The ER retention sequence did not reduce the antimicrobial activity of chemically synthesized BP100 derivatives, making this strategy possible. Transformation with sequences encoding BP100 derivatives (bp100der was over ten-fold less efficient than that of the hygromycin phosphotransferase (hptII transgene. The BP100 direct tandems did not show higher antimicrobial activity than BP100, and genetically modified (GM plants constitutively expressing them were not viable. In contrast, inverted repeats of BP100, whether or not elongated with a portion of a natural antimicrobial peptide (AMP, had higher antimicrobial activity, and fertile GM rice lines constitutively expressing bp100der were produced. These GM lines had increased resistance to the pathogens Dickeya chrysanthemi and Fusarium verticillioides, and tolerance to oxidative stress, with agronomic performance comparable to untransformed lines. Conclusions Constitutive expression of transgenes encoding short cationic α-helical synthetic peptides can have a strong negative impact on rice fitness. However, GM

Stimulation of Interleukin-10 Production by Acidic β-Lactoglobulin-Derived Peptides Hydrolyzed with Lactobacillus paracasei NCC2461 Peptidases

OpenAIRE

Prioult, Guénolée; Pecquet, Sophie; Fliss, Ismail

2004-01-01

We have previously demonstrated that Lactobacillus paracasei NCC2461 may help to prevent cow's milk allergy in mice by inducing oral tolerance to β-lactoglobulin (BLG). To investigate the mechanisms involved in this beneficial effect, we examined the possibility that L. paracasei induces tolerance by hydrolyzing BLG-derived peptides and liberating peptides that stimulate interleukin-10 (IL-10) production. L. paracasei peptidases have been shown to hydrolyze tryptic-chymotryptic peptides from ...

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

Structural properties of a peptide derived from H+-V-ATPase subunit a

NARCIS (Netherlands)

Vermeer, L.S.; Reat, V.; Hemminga, M.A.; Milon, A.

2009-01-01

The 3D structure of a peptide derived from the putative transmembrane segment 7 (TM7) of subunit a from H+-V-ATPase from Saccharomyces cerevisiae has been determined by solution state NMR in SDS. A stable helix is formed from L736 up to and including Q745, the lumenal half of the putative TM7. The

A Chimeric Peptide Composed of a Dermaseptin Derivative and an RNA III-Inhibiting Peptide Prevents Graft-Associated Infections by Antibiotic-Resistant Staphylococci

Science.gov (United States)

Balaban, Naomi; Gov, Yael; Giacometti, Andrea; Cirioni, Oscar; Ghiselli, Roberto; Mocchegiani, Federico; Orlando, Fiorenza; D'Amato, Giuseppina; Saba, Vittorio; Scalise, Giorgio; Bernes, Sabina; Mor, Amram

2004-01-01

Staphylococcal bacteria are a prevalent cause of infections associated with foreign bodies and indwelling medical devices. Bacteria are capable of escaping antibiotic treatment through encapsulation into biofilms. RNA III-inhibiting peptide (RIP) is a heptapeptide that inhibits staphylococcal biofilm formation by obstructing quorum-sensing mechanisms. K4-S4(1-13)a is a 13-residue dermaseptin derivative (DD13) believed to kill bacteria via membrane disruption. We tested each of these peptides as well as a hybrid construct, DD13-RIP, for their ability to inhibit bacterial proliferation and suppress quorum sensing in vitro and for their efficacy in preventing staphylococcal infection in a rat graft infection model with methicillin-resistant Staphylococcus aureus (MRSA) or S. epidermidis (MRSE). In vitro, proliferation assays demonstrated that RIP had no inhibitory effect, while DD13-RIP and DD13 were equally effective, and that the chimeric peptide but not DD13 was slightly more effective than RIP in inhibiting RNA III synthesis, a regulatory RNA molecule important for staphylococcal pathogenesis. In vivo, the three peptides reduced graft-associated bacterial load in a dose-dependent manner, but the hybrid peptide was most potent in totally preventing staphylococcal infections at the lowest dose. In addition, each of the peptides acted synergistically with antibiotics. The data indicate that RIP and DD13 act in synergy by attacking bacteria simultaneously by two different mechanisms. Such a chimeric peptide may be useful for coating medical devices to prevent drug-resistant staphylococcal infections. PMID:15215107

Determination of Free-Form and Peptide Bound Pyrraline in the Commercial Drinks Enriched with Different Protein Hydrolysates

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Zhili Liang

2016-07-01

Full Text Available Pyrraline, a causative factor for the recent epidemics of diabetes and cardiovascular disease, is also employed as an indicator to evaluate heat damage and formation of advanced glycation end-products (AGEs in foods. Peptide-enriched drinks (PEDs are broadly consumed worldwide due to rapid rate of absorption and perceived health effects. It can be hypothesized that PED is an important source of pyrraline, especially peptide bound pyrraline (Pep-Pyr. In this study we determined free-form pyrraline (Free-Pyr and Pep-Pyr in drinks enriched with whey protein hydrolysate (WPH, soy protein hydrolysate (SPH and collagen protein hydrolysate (CPH. A detection method was developed using ultrahigh-performance liquid chromatography with UV-visible detector coupled with tandem mass spectrometry after solid-phase extraction (SPE. The SPE led to excellent recovery rates ranging between 93.2% and 98.5% and a high reproducibility with relative standard deviations (RSD of <5%. The limits of detection and quantification obtained were 30.4 and 70.3 ng/mL, respectively. Pep-Pyr was identified as the most abundant form (above 96 percent of total pyrraline, whereas Free-Pyr was present in a small proportion (less than four percent of total pyrraline. The results indicate that PED is an important extrinsic source of pyrraline, especially Pep-Pyr. As compared with CPH- and SPH-enriched drinks, WPH-enriched drinks contained high content of Pep-Pyr. The Pep-Pyr content is associated with the distribution of peptide lengths and the amino acid compositions of protein in PEDs.

Penetration of Milk-Derived Antimicrobial Peptides into Phospholipid Monolayers as Model Biomembranes

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Wanda Barzyk

2013-01-01

Full Text Available Three antimicrobial peptides derived from bovine milk proteins were examined with regard to penetration into insoluble monolayers formed with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC or 1,2-dipalmitoyl-sn-glycero-3-phospho-rac-(1-glycerol sodium salt (DPPG. Effects on surface pressure (Π and electric surface potential (ΔV were measured, Π with a platinum Wilhelmy plate and ΔV with a vibrating plate. The penetration measurements were performed under stationary diffusion conditions and upon the compression of the monolayers. The two type measurements showed greatly different effects of the peptide-lipid interactions. Results of the stationary penetration show that the peptide interactions with DPPC monolayer are weak, repulsive, and nonspecific while the interactions with DPPG monolayer are significant, attractive, and specific. These results are in accord with the fact that antimicrobial peptides disrupt bacteria membranes (negative while no significant effect on the host membranes (neutral is observed. No such discrimination was revealed from the compression isotherms. The latter indicate that squeezing the penetrant out of the monolayer upon compression does not allow for establishing the penetration equilibrium, so the monolayer remains supersaturated with the penetrant and shows an under-equilibrium orientation within the entire compression range, practically.

Improving surface functional properties of tofu whey-derived peptides by chemical modification with fatty acids.

Science.gov (United States)

Matemu, Athanasia Oswald; Katayama, Shigeru; Kayahara, Hisataka; Murasawa, Hisashi; Nakamura, Soichiro

2012-04-01

Effect of acylation with saturated fatty acids on surface functional properties of tofu whey-derived peptides was investigated. Tofu whey (TW) and soy proteins (7S, 11S, and acid-precipitated soy protein [APP]) were hydrolyzed by Protease M 'Amano' G, and resulting peptide mixtures were acylated with esterified fatty acids of different chain length (6C to 18C) to form a covalent linkage between the carboxyl group of fatty acid and the free amino groups of peptide. Acylation significantly (P properties of 7S, 11S, and APP peptides independent of fatty acid chain length. Acylation decreased water binding capacity although oil binding capacity of acylated tofu whey ultra filtered fraction (UFTW acids had shown significant higher surface hydrophobicity as in contrast with acylated UFTW acids can further affect functional properties of soy proteins. © 2012 Institute of Food Technologists®

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.

Quantification of VGF- and pro-SAAS-derived peptides in endocrine tissues and the brain, and their regulation by diet and cold stress.

Science.gov (United States)

Chakraborty, Tandra R; Tkalych, Oleg; Nanno, Daniela; Garcia, Angelo L; Devi, Lakshmi A; Salton, Stephen R J

2006-05-17

Two novel granin-like polypeptides, VGF and pro-SAAS, which are stored in and released from secretory vesicles and are expressed widely in nervous, endocrine, and neuroendocrine tissues, play roles in the regulation of body weight, feeding, and energy expenditure. Both VGF and pro-SAAS are cleaved into peptide fragments, several of which are biologically active. We utilized a highly sensitive and specific radioimmunoassay (RIA) to immunoreactive, pro-SAAS-derived PEN peptides, developed another against immunoreactive, VGF-derived AQEE30 peptides, and quantified these peptides in various mouse tissues and brain regions. Immunoreactive AQEE30 was most abundant in the pituitary, while brain levels were highest in hypothalamus, striatum, and frontal cortex. Immunoreactive PEN levels were highest in the pancreas and spinal cord, and in brain, PEN was most abundant in striatum, hippocampus, pons and medulla, and cortex. Since both peptides were expressed in hypothalamus, a region of the brain that controls feeding and energy expenditure, double label immunofluorescence studies were employed. These demonstrated that 42% of hypothalamic arcuate neurons coexpress VGF and SAAS peptides, and that the intracellular distributions of these peptides in arcuate neurons differed. By RIA, cold stress increased immunoreactive AQEE30 and PEN peptide levels in female but not male hypothalamus, while a high fat diet increased AQEE30 and PEN peptide levels in female but not male hippocampus. VGF and SAAS-derived peptides are therefore widely expressed in endocrine, neuroendocrine, and neural tissues, can be accurately quantified by RIA, and are differentially regulated in the brain by diet and cold stress.

Antibacterial activity of lactoferrin and a pepsin-derived lactoferrin peptide fragment.

OpenAIRE

Yamauchi, K; Tomita, M; Giehl, T J; Ellison, R T

1993-01-01

Although the antimicrobial activity of lactoferrin has been well described, its mechanism of action has been poorly characterized. Recent work has indicated that in addition to binding iron, human lactoferrin damages the outer membrane of gram-negative bacteria. In this study, we determined whether bovine lactoferrin and a pepsin-derived bovine lactoferrin peptide (lactoferricin) fragment have similar activities. We found that both 20 microM bovine lactoferrin and 20 microM lactoferricin rele...

N-Acylated and d Enantiomer Derivatives of a Nonamer Core Peptide of Lactoferricin B Showing Improved Antimicrobial Activity

OpenAIRE

Wakabayashi, Hiroyuki; Matsumoto, Hiroshi; Hashimoto, Koichi; Teraguchi, Susumu; Takase, Mitsunori; Hayasawa, Hirotoshi

1999-01-01

N-acylated or d enantiomer peptide derivatives based on the sequence RRWQWRMKK in lactoferricin B demonstrated antimicrobial activities greater than those of lactoferricin B against bacteria and fungi. The most potent peptide, conjugated with an 11-carbon-chain acyl group, showed two to eight times lower MIC than lactoferricin B.

N-Acylated and D enantiomer derivatives of a nonamer core peptide of lactoferricin B showing improved antimicrobial activity.

Science.gov (United States)

Wakabayashi, H; Matsumoto, H; Hashimoto, K; Teraguchi, S; Takase, M; Hayasawa, H

1999-05-01

N-acylated or D enantiomer peptide derivatives based on the sequence RRWQWRMKK in lactoferricin B demonstrated antimicrobial activities greater than those of lactoferricin B against bacteria and fungi. The most potent peptide, conjugated with an 11-carbon-chain acyl group, showed two to eight times lower MIC than lactoferricin B.

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 ...

Spontaneous human squamous cell carcinomas are killed by a human cytotoxic T lymphocyte clone recognizing a wild-type p53-derived peptide

DEFF Research Database (Denmark)

Röpke, M; Hald, J; Guldberg, Per

1996-01-01

p53 genes, in a L9V/HLA-A2 specific and restricted fashion. Thus, the normal tolerance against endogenously processed p53 protein-derived self-epitopes can be broken by peptide-specific in vitro priming. p53 protein-derived wild-type peptides might thus represent tumor associated target molecules...

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.

Predicting binding affinities of protein ligands from three-dimensional models: application to peptide binding to class I major histocompatibility proteins

DEFF Research Database (Denmark)

Rognan, D; Lauemoller, S L; Holm, A

1999-01-01

A simple and fast free energy scoring function (Fresno) has been developed to predict the binding free energy of peptides to class I major histocompatibility (MHC) proteins. It differs from existing scoring functions mainly by the explicit treatment of ligand desolvation and of unfavorable protein...... coordinates of the MHC-bound peptide have first been determined with an accuracy of about 1-1.5 A. Furthermore, it may be easily recalibrated for any protein-ligand complex.......) and of a series of 16 peptides to H-2K(k). Predictions were more accurate for HLA-A2-binding peptides as the training set had been built from experimentally determined structures. The average error in predicting the binding free energy of the test peptides was 3.1 kJ/mol. For the homology model-derived equation...

Molecular characterization of covalent complexes between tissue transglutaminase and gliadin peptides

DEFF Research Database (Denmark)

Fleckenstein, Burkhard; Qiao, Shuo-Wang; Larsen, Martin Røssel

2004-01-01

recognized by intestinal T cells from patients. Incubation of TG2 with gliadin peptides also results in the formation of covalent TG2-peptide complexes. Here we report the characterization of complexes between TG2 and two immunodominant gliadin peptides. Two types of covalent complexes were found......; the peptides are either linked via a thioester bond to the active site cysteine of TG2 or via isopeptide bonds to particular lysine residues of the enzyme. We quantified the number of gliadin peptides bound to TG2 under different conditions. After 30 min of incubation of TG2 at 1 microm with an equimolar ratio...... of peptides to TG2, approximately equal amounts of peptides were bound by thioester and isopeptide linkage. At higher peptide to TG2 ratios, more than one peptide was linked to TG2, and isopeptide bond formation dominated. The lysine residues in TG2 that act as acyl acceptors were identified by matrix...

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.

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

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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.

Apoptotic death of Listeria monocytogenes-infected human macrophages induced by lactoferricin B, a bovine lactoferrin-derived peptide.

Science.gov (United States)

Longhi, C; Conte, M P; Ranaldi, S; Penta, M; Valenti, P; Tinari, A; Superti, F; Seganti, L

2005-01-01

Listeria monocytogenes, an intracellular facultative food-borne pathogen, was reported to induce apoptosis in vitro and in vivo in a variety of cell types with the exception of murine macrophages. These cells represent the predominant compartment of bacterial multiplication and die as a result of necrosis. In this study we showed that human non-activated and IFN-gamma-activated macrophagic-like (THP-1) cells infected with L. monocytogenes, mainly die by necrosis rather than by an apoptotic process. Two natural products derived from bovine milk, lactoferrin and its derivative peptide lactoferricin B, are capable of regulating the fate of infected human macrophages. Bovine lactoferrin treatment of macrophages protects them from L. monocytogenes-induced death whereas lactoferricin B, its derivative peptide, determines a shifting of the equilibrium from necrosis to apoptosis.

Comparative antimicrobial activity and mechanism of action of bovine lactoferricin-derived synthetic peptides.

Science.gov (United States)

Liu, Yifan; Han, Feifei; Xie, Yonggang; Wang, Yizhen

2011-12-01

Lactoferricin B (LfcinB), a 25 residue peptide derived from the N-terminal of bovine lactoferrin (bLF), causes depolarization of the cytoplasmic membrane in susceptible bacteria. Its mechanism of action, however, still needs to be elucidated. In the present study, synthetic LfcinB (without a disulfide bridge) and LfcinB (C-C; with a disulfide bridge) as well as three derivatives with 15-, 11- and 9-residue peptides were prepared to investigate their antimicrobial nature and mechanisms. The antimicrobial properties were measured via minimum inhibitory concentration (MIC) determinations, killing kinetics assays and synergy testing, and hemolytic activities were assessed by hemoglobin release. Finally, the morphology of peptide-treated bacteria was determined by atomic force microscopy (AFM). We found that there was no difference in MICs between LfcinB and LfcinB (C-C). Among the derivatives, only LfcinB15 maintained nearly the same level as LfcinB, in the MIC range of 16-128 μg/ml, and the MICs of LfcinB11 (64-256 μg/ml) were 4 times more than LfcinB, while LfcinB9 exhibited the lowest antimicrobial activity. When treated at MIC for 1 h, many blebs were formed and holes of various sizes appeared on the cell surface, but the cell still maintained its integrity. This suggested that LfcinB had a major permeability effect on the cytoplasmic membrane of both Gram-positive and Gram-negative bacteria, which also indicated it may be a possible intracellular target. Among the tested antibiotics, aureomycin increased the bactericidal activity of LfcinB against E. coli, S. aureus and P. aeruginosa, but neomycin did not have such an effect. We also found that the combination of cecropin A and LfcinB had synergistic effects against E. coli.

Ghrelin-derived peptides: a link between appetite/reward, GH axis and psychiatric disorders ?

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Alexandra eLabarthe

2014-10-01

Full Text Available Psychiatric disorders are often associated with metabolic and hormonal alterations, including obesity, diabetes, metabolic syndrome as well as modifications in several biological rhythms including appetite, stress, sleep-wake cycles and secretion of their corresponding endocrine regulators.Among the gastrointestinal hormones that regulate appetite and adapt the metabolism in response to nutritional, hedonic and emotional dysfunctions, at the interface between endocrine, metabolic and psychiatric disorders, ghrelin plays a unique role as the only one increasing appetite. The secretion of ghrelin is altered in several psychiatric disorders (anorexia, schizophrenia as well as in metabolic disorders (obesity and in animal models in response to emotional triggers (psychological stress, …. but the relationship between these modifications and the physiopathology of psychiatric disorders remains unclear. Recently, a large literature showed that this key metabolic/endocrine regulator is involved in stress and reward-oriented behaviors and regulates anxiety and mood. In addition, preproghrelin is a complex prohormone but the roles of the other ghrelin-derived peptides, thought to act as functional ghrelin antagonists, are largely unknown. Altered ghrelin secretion and/or signaling in psychiatric diseases are thought to participate in altered appetite, hedonic response and reward. Whether this can contribute to the mechanism responsible for the development of the disease or can help to minimize some symptoms associated with these psychiatric disorders is discussed in the present review. We will thus describe 1 the biological actions of ghrelin and ghrelin-derived peptides on food and drugs reward, anxiety and depression, and the physiological consequences of ghrelin invalidation on these parameters, 2 how ghrelin and ghrelin-derived peptides are regulated in animal models of psychiatric diseases and in human psychiatric disorders in relation with the GH

Hydroxamic acid derivatives as potent peptide deformylase inhibitors and antibacterial agents.

Science.gov (United States)

Apfel, C; Banner, D W; Bur, D; Dietz, M; Hirata, T; Hubschwerlen, C; Locher, H; Page, M G; Pirson, W; Rossé, G; Specklin, J L

2000-06-15

Low-molecular-weight beta-sulfonyl- and beta-sulfinylhydroxamic acid derivatives have been synthesized and found to be potent inhibitors of Escherichia coli peptide deformylase (PDF). Most of the compounds synthesized and tested displayed antibacterial activities that cover several pathogens found in respiratory tract infections, including Chlamydia pneumoniae, Mycoplasma pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. The potential of these compounds as antibacterial agents is discussed with respect to selectivity, intracellular concentrations in bacteria, and potential for resistance development.

Comparison of some dispersion-corrected and traditional functionals as applied to peptides and conformations of cyclohexane derivatives

Science.gov (United States)

Marianski, Mateusz; Asensio, Amparo; Dannenberg, J. J.

2012-07-01

We compare the energetic and structural properties of fully optimized α-helical and antiparallel β-sheet polyalanines and the energetic differences between axial and equatorial conformations of three cyclohexane derivatives (methyl, fluoro, and chloro) as calculated using several functionals designed to treat dispersion (B97-D, ωB97x-D, M06, M06L, and M06-2X) with other traditional functionals not specifically parametrized to treat dispersion (B3LYP, X3LYP, and PBE1PBE) and with experimental results. Those functionals developed to treat dispersion significantly overestimate interaction enthalpies of folding for the α-helix and predict unreasonable structures that contain Ramachandran ϕ and ψ and C = O…N H-bonding angles that are out of the bounds of databases compiled the β-sheets. These structures are consistent with overestimation of the interaction energies. For the cyclohexanes, these functionals overestimate the stabilities of the axial conformation, especially when used with smaller basis sets. Their performance improves when the basis set is improved from D95** to aug-cc-pVTZ (which would not be possible with systems as large as the peptides).

High resolution crystal structure of the Grb2 SH2 domain with a phosphopeptide derived from CD28.

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Kunitake Higo

Full Text Available Src homology 2 (SH2 domains play a critical role in cellular signal transduction. They bind to peptides containing phosphotyrosine (pY with various specificities that depend on the flanking amino-acid residues. The SH2 domain of growth-factor receptor-bound protein 2 (Grb2 specifically recognizes pY-X-N-X, whereas the SH2 domains in phosphatidylinositol 3-kinase (PI3K recognize pY-X-X-M. Binding of the pY site in CD28 (pY-M-N-M by PI3K and Grb2 through their SH2 domains is a key step that triggers the CD28 signal transduction for T cell activation and differentiation. In this study, we determined the crystal structure of the Grb2 SH2 domain in complex with a pY-containing peptide derived from CD28 at 1.35 Å resolution. The peptide was found to adopt a twisted U-type conformation, similar to, but distinct from type-I β-turn. In all previously reported crystal structures, the peptide bound to the Grb2 SH2 domains adopts a type-I β-turn conformation, except those with a proline residue at the pY+3 position. Molecular modeling also suggests that the same peptide bound to PI3K might adopt a very different conformation.

High resolution crystal structure of the Grb2 SH2 domain with a phosphopeptide derived from CD28.

Science.gov (United States)

Higo, Kunitake; Ikura, Teikichi; Oda, Masayuki; Morii, Hisayuki; Takahashi, Jun; Abe, Ryo; Ito, Nobutoshi

2013-01-01

Src homology 2 (SH2) domains play a critical role in cellular signal transduction. They bind to peptides containing phosphotyrosine (pY) with various specificities that depend on the flanking amino-acid residues. The SH2 domain of growth-factor receptor-bound protein 2 (Grb2) specifically recognizes pY-X-N-X, whereas the SH2 domains in phosphatidylinositol 3-kinase (PI3K) recognize pY-X-X-M. Binding of the pY site in CD28 (pY-M-N-M) by PI3K and Grb2 through their SH2 domains is a key step that triggers the CD28 signal transduction for T cell activation and differentiation. In this study, we determined the crystal structure of the Grb2 SH2 domain in complex with a pY-containing peptide derived from CD28 at 1.35 Å resolution. The peptide was found to adopt a twisted U-type conformation, similar to, but distinct from type-I β-turn. In all previously reported crystal structures, the peptide bound to the Grb2 SH2 domains adopts a type-I β-turn conformation, except those with a proline residue at the pY+3 position. Molecular modeling also suggests that the same peptide bound to PI3K might adopt a very different conformation.

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.

A Tetrameric Peptide Derived from Bovine Lactoferricin Exhibits Specific Cytotoxic Effects against Oral Squamous-Cell Carcinoma Cell Lines.

Science.gov (United States)

Solarte, Víctor A; Rosas, Jaiver E; Rivera, Zuly J; Arango-Rodríguez, Martha L; García, Javier E; Vernot, Jean-Paul

2015-01-01

Several short linear peptides derived from cyclic bovine lactoferricin were synthesized and tested for their cytotoxic effect against the oral cavity squamous-cell carcinoma (OSCC) cell lines CAL27 and SCC15. As a control, an immortalized and nontumorigenic cell line, Het-1A, was used. Linear peptides based on the RRWQWR core sequence showed a moderate cytotoxic effect and specificity towards tumorigenic cells. A tetrameric peptide, LfcinB(20-25)4, containing the RRWQWR motif, exhibited greater cytotoxic activity (>90%) in both OSCC cell lines compared to the linear lactoferricin peptide or the lactoferrin protein. Additionally, this tetrameric peptide showed the highest specificity towards tumorigenic cells among the tested peptides. Interestingly, this effect was very fast, with cell shrinkage, severe damage to cell membrane permeability, and lysis within one hour of treatment. Our results are consistent with a necrotic effect rather than an apoptotic one and suggest that this tetrameric peptide could be considered as a new candidate for the therapeutic treatment of OSCC.

Anti-endotoxic and antibacterial effects of a dermal substitute coated with host defense peptides.

Science.gov (United States)

Kasetty, Gopinath; Kalle, Martina; Mörgelin, Matthias; Brune, Jan C; Schmidtchen, Artur

2015-01-01

Biomaterials used during surgery and wound treatment are of increasing importance in modern medical care. In the present study we set out to evaluate the addition of thrombin-derived host defense peptides to human acellular dermis (hAD, i.e. epiflex(®)). Antimicrobial activity of the functionalized hAD was demonstrated using radial diffusion and viable count assays against Gram-negative Escherichia coli, Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus bacteria. Electron microscopy analyses showed that peptide-mediated bacterial killing led to reduced hAD degradation. Furthermore, peptide-functionalized hAD displayed endotoxin-binding activity in vitro, as evidenced by inhibition of NF-κB activation in human monocytic cells (THP-1 cells) and a reduction of pro-inflammatory cytokine production in whole blood in response to lipopolysaccharide stimulation. The dermal substitute retained its anti-endotoxic activity after washing, compatible with results showing that the hAD bound a significant amount of peptide. Furthermore, bacteria-induced contact activation was inhibited by peptide addition to the hAD. E. coli infected hAD, alone, or after treatment with the antiseptic substance polyhexamethylenebiguanide (PHMB), yielded NF-κB activation in THP-1 cells. The activation was abrogated by peptide addition. Thus, thrombin-derived HDPs should be of interest in the further development of new biomaterials with combined antimicrobial and anti-endotoxic functions for use in surgery and wound treatment. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

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...

Amyloid fibril formation of peptides derived from the C-terminus of CETP modulated by lipids

Energy Technology Data Exchange (ETDEWEB)

García-González, Victor [Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, 04510 México, DF (Mexico); Mas-Oliva, Jaime, E-mail: jmas@ifc.unam.mx [Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, 04510 México, DF (Mexico); División de Investigación, Facultad de Medicina, Universidad Nacional Autónoma de México, 04510 México, DF (Mexico)

2013-04-26

Highlights: •The secondary structure of a C-terminal peptide derived from CETP was studied. •Lipids modulate secondary structure changes of a C-terminal peptide derived from CETP. •Lysophosphatidic acid maintains a functional α-helix and prevents fibril formation. •Transfer of lipids by CETP is related to the presence of an α-helix at its C-end. -- Abstract: Cholesteryl-ester transfer protein (CETP) is a plasmatic protein involved in neutral lipid transfer between lipoproteins. Focusing on the last 12 C-terminus residues we have previously shown that mutation D{sub 470}N promotes a conformational change towards a β-secondary structure. In turn, this modification leads to the formation of oligomers and fibrillar structures, which cause cytotoxic effects similar to the ones provoked by amyloid peptides. In this study, we evaluated the role of specific lipid arrangements on the structure of peptide helix-Z (D{sub 470}N) through the use of thioflavin T fluorescence, peptide bond absorbance, circular dichroism and electron microscopy. The results indicate that the use of micelles formed with lysophosphatidylcholine and lysophosphatidic acid (LPA) under neutral pH induce a conformational transition of peptide helix-Z containing a β-sheet conformation to a native α-helix structure, therefore avoiding the formation of amyloid fibrils. In contrast, incubation with phosphatidic acid does not change the profile for the β-sheet conformation. When the electrostatic charge at the surface of micelles or vesicles is regulated through the use of lipids such as phospholipid and LPA, minimal changes and the presence of β-structures were recorded. Mixtures with a positive net charge diminished the percentage of β-structure and the amount of amyloid fibrils. Our results suggest that the degree of solvation determined by the presence of a free hydroxyl group on lipids such as LPA is a key condition that can modulate the secondary structure and the consequent formation of

Amyloid fibril formation of peptides derived from the C-terminus of CETP modulated by lipids

International Nuclear Information System (INIS)

García-González, Victor; Mas-Oliva, Jaime

2013-01-01

Highlights: •The secondary structure of a C-terminal peptide derived from CETP was studied. •Lipids modulate secondary structure changes of a C-terminal peptide derived from CETP. •Lysophosphatidic acid maintains a functional α-helix and prevents fibril formation. •Transfer of lipids by CETP is related to the presence of an α-helix at its C-end. -- Abstract: Cholesteryl-ester transfer protein (CETP) is a plasmatic protein involved in neutral lipid transfer between lipoproteins. Focusing on the last 12 C-terminus residues we have previously shown that mutation D 470 N promotes a conformational change towards a β-secondary structure. In turn, this modification leads to the formation of oligomers and fibrillar structures, which cause cytotoxic effects similar to the ones provoked by amyloid peptides. In this study, we evaluated the role of specific lipid arrangements on the structure of peptide helix-Z (D 470 N) through the use of thioflavin T fluorescence, peptide bond absorbance, circular dichroism and electron microscopy. The results indicate that the use of micelles formed with lysophosphatidylcholine and lysophosphatidic acid (LPA) under neutral pH induce a conformational transition of peptide helix-Z containing a β-sheet conformation to a native α-helix structure, therefore avoiding the formation of amyloid fibrils. In contrast, incubation with phosphatidic acid does not change the profile for the β-sheet conformation. When the electrostatic charge at the surface of micelles or vesicles is regulated through the use of lipids such as phospholipid and LPA, minimal changes and the presence of β-structures were recorded. Mixtures with a positive net charge diminished the percentage of β-structure and the amount of amyloid fibrils. Our results suggest that the degree of solvation determined by the presence of a free hydroxyl group on lipids such as LPA is a key condition that can modulate the secondary structure and the consequent formation of amyloid

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...

A biomimetic collagen derived peptide exhibits anti-angiogenic activity in triple negative breast cancer.

Directory of Open Access Journals (Sweden)

Elena V Rosca

Full Text Available We investigated the application of a mimetic 20 amino acid peptide derived from type IV collagen for treatment of breast cancer. We showed that the peptide induced a decrease of proliferation, adhesion, and migration of endothelial and tumor cells in vitro. We also observed an inhibition of triple negative MDA-MB-231 xenograft growth by 75% relative to control when administered intraperitoneally for 27 days at 10 mg/kg. We monitored in vivo the changes in vascular properties throughout the treatment using MRI and found that the vascular volume and permeability surface area product decreased significantly. The treatment also resulted in an increase of caspase-3 activity and in a reduction of microvascular density. The multiple mode of action of this peptide, i.e., anti-angiogenic, and anti-tumorigenic, makes it a viable candidate as a therapeutic agent as a monotherapy or in combination with other compounds.

Electron Capture Dissociation of Weakly Bound Polypeptide Polycationic Complexes

DEFF Research Database (Denmark)

Haselmann, Kim F; Jørgensen, Thomas J D; Budnik, Bogdan A

2002-01-01

as well as specific complexes of modified glycopeptide antibiotics with their target peptide. The weak nature of bonding is substantiated by blackbody infrared dissociation, low-energy collisional excitation and force-field simulations. The results are consistent with a non-ergodic ECD cleavage mechanism.......We have previously reported that, in electron capture dissociation (ECD), rupture of strong intramolecular bonds in weakly bound supramolecular aggregates can proceed without dissociation of weak intermolecular bonds. This is now illustrated on a series of non-specific peptide-peptide dimers...

A novel affinity purification method to isolate peptide specific antibodies

DEFF Research Database (Denmark)

Karlsen, Alan E; Lernmark, A; Kofod, Hans

1990-01-01

Site-specific, high affinity polyclonal antisera are effectively and successfully produced by immunizing rabbits with synthetic peptides. The use of these antisera in subsequent immune analysis is often limited because of non-specific binding. We describe a new and simple method to effectively...... affinity-purify anti-peptide antibodies. To test our system, rabbits were immunized with model peptides representing sequences of the putative rabbit growth hormone receptor and several HLA-DQ beta-chain molecules. Polystyrene plastic beads were coated with peptides. Immune serum was incubated...... with the beads and after a wash step the bound antibodies were eluted in 1 M acetic acid. The eluted material was composed predominantly of intact immunoglobulin as evidenced by the presence of heavy and light chain bands in SDS-PAGE. The eluted antibodies were peptide specific in ELISA and bound only to intact...

Antibacterial activity in bovine lactoferrin-derived peptides.

Science.gov (United States)

Hoek, K S; Milne, J M; Grieve, P A; Dionysius, D A; Smith, R

1997-01-01

Several peptides sharing high sequence homology with lactoferricin B (Lf-cin B) were generated from bovine lactoferrin (Lf) with recombinant chymosin. Two peptides were copurified, one identical to Lf-cin B and another differing from Lf-cin B by the inclusion of a C-terminal alanine (lactoferricin). Two other peptides were copurified from chymosin-hydrolyzed Lf, one differing from Lf-cin B by the inclusion of C-terminal alanyl-leucine and the other being a heterodimer linked by a disulfide bond. These peptides were isolated in a single step from chymosin-hydrolyzed Lf by membrane ion-exchange chromatography and were purified by reverse-phase high-pressure liquid chromatography (HPLC). They were characterized by N-terminal Edman sequencing, mass spectrometry, and antibacterial activity determination. Pure lactoferricin, prepared from pepsin-hydrolyzed Lf, was purified by standard chromatography techniques. This peptide was analyzed against a number of gram-positive and gram-negative bacteria before and after reduction of its disulfide bond or cleavage after its single methionine residue and was found to inhibit the growth of all the test bacteria at a concentration of 8 microM or less. Subfragments of lactoferricin were isolated from reduced and cleaved peptide by reverse-phase HPLC. Subfragment 1 (residues 1 to 10) was active against most of the test microorganisms at concentrations of 10 to 50 microM. Subfragment 2 (residues 11 to 26) was active against only a few microorganisms at concentrations up to 100 microM. These antibacterial studies indicate that the activity of lactoferricin is mainly, but not wholly, due to its N-terminal region. PMID:8980754

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

AWRK6, A Synthetic Cationic Peptide Derived from Antimicrobial Peptide Dybowskin-2CDYa, Inhibits Lipopolysaccharide-Induced Inflammatory Response

Directory of Open Access Journals (Sweden)

Qiuyu Wang

2018-02-01

Full Text Available Lipopolysaccharides (LPS are major outer membrane components of Gram-negative bacteria and produce strong inflammatory responses in animals. Most antibiotics have shown little clinical anti-endotoxin activity while some antimicrobial peptides have proved to be effective in blocking LPS. Here, the anti-LPS activity of the synthetic peptide AWRK6, which is derived from antimicrobial peptide dybowskin-2CDYa, has been investigated in vitro and in vivo. The positively charged α-helical AWRK6 was found to be effective in blocking the binding of LBP (LPS binding protein with LPS in vitro using ELISA. In a murine endotoxemia model, AWRK6 offered satisfactory protection efficiency against endotoxemia death, and the serum levels of LPS, IL-1β, IL-6, and TNF-α were found to be attenuated using ELISA. Further, histopathological analysis suggested that AWRK6 could improve the healing of liver and lung injury in endotoxemia mice. The results of real-time PCR and Western blotting showed that AWRK6 significantly reversed LPS-induced TLR4 overexpression and IκB depression, as well as the enhanced IκB phosphorylation. Additionally, AWRK6 did not produce any significant toxicity in vivo and in vitro. In summary, AWRK6 showed efficacious protection from LPS challenges in vivo and in vitro, by blocking LPS binding to LBP, without obvious toxicity, providing a promising strategy against LPS-induced inflammatory responses.

A cyclic peptide derived from alpha-fetoprotein inhibits the proliferative effects of the epidermal growth factor and estradiol in MCF7 cells.

Science.gov (United States)

Torres, Cristian; Antileo, Elmer; Epuñán, Maráa José; Pino, Ana María; Valladares, Luis Emilio; Sierralta, Walter Daniel

2008-06-01

A cyclic peptide derived from the active domain of alpha-fetoprotein (AFP) significantly inhibited the proliferation of MCF7 cells stimulated with the epidermal growth factor (EGF) or estradiol (E2). The action of these three agents on cell growth was independent of the presence of calf serum in the culture medium. Our results demonstrated that the cyclic peptide interfered markedly with the regulation of MAPK by activated c-erbB2. The cyclic peptide showed no effect on the E2-stimulated release of matrix metalloproteinases 2 and 9 nor on the shedding of heparin-binding EGF into the culture medium. We propose that the AFP-derived cyclic peptide represents a valuable novel antiproliferative agent for treating breast cancer.

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.

Chimeric opioid peptides: tools for identifying opioid receptor types.

OpenAIRE

Xie, G X; Miyajima, A; Yokota, T; Arai, K; Goldstein, A

1990-01-01

We synthesized several chimeric peptides in which the N-terminal nine residues of dynorphin-32, a peptide selective for the kappa opioid receptor, were replaced by opioid peptides selective for other opioid receptor types. Each chimeric peptide retained the high affinity and type selectivity characteristic of its N-terminal sequence. The common C-terminal two-thirds of the chimeric peptides served as an epitope recognized by the same monoclonal antibody. When bound to receptors on a cell surf...

γ-Preprotachykinin-(72-92)-peptide amide: An endogenous preprotachykinin I gene-derived peptide that preferentially binds to neurokinin-2 receptors

International Nuclear Information System (INIS)

Dam, T.V.; Takeda, Y.; Krause, J.E.; Escher, E.; Quirion, R.

1990-01-01

The presence of N-terminally extended forms of neurokinin A has recently been reported in the mammalian brain. Among them, gamma-preprotachykinin-(72-92)-peptide amide [gamma-PPT-(72-92)-NH2], a peptide derived by posttranslational processing of gamma-preprotachykinin, is most prominent. We report here that this peptide most likely acts on neurokinin-2 receptor sites since neurokinin A (a putative neurokinin-2 agonist) and gamma-PPT-(72-92)-NH2 are potent competitors of 125I-labeled gamma-PPT-(72-92)-NH2 binding whereas selective neurokinin-1 and -3 agonists are not. Moreover, the distribution of 125I-labeled gamma-PPT-(72-92)-NH2 and 125I-labeled neurokinin A binding sites are very similar in rat brain. On the other hand, 125I-labeled Bolton-Hunter-substance P (a neurokinin-1 ligand) and 125I-labeled Bolton-Hunter-eledoisin (a neurokinin-3 ligand) binding sites are differentially located in this tissue. Thus, it appears that gamma-PPT-(72-92)-NH2 binds to neurokinin-2 receptors and should be considered as a putative endogenous ligand for this receptor class

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.

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

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.

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

Connecting peptide (c-peptide) and the duration of diabetes mellitus ...

African Journals Online (AJOL)

Objective: C-peptide is derived from proinsulin and it is secreted in equimolar concentration with insulin. Plasma C-peptide is more stable than insulin and it provides an indirect measure of insulin secretory reserve and beta cell function. To determine relationship between C-peptide and duration of diabetes mellitus, age, ...

A novel small peptide as an epidermal growth factor receptor targeting ligand for nanodelivery in vitro

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Han CY

2013-04-01

Full Text Available Cui-yan Han,1,2 Li-ling Yue,2 Ling-yu Tai,1 Li Zhou,2 Xue-yan Li,2 Gui-hua Xing,2 Xing-gang Yang,1 Ming-shuang Sun,1 Wei-san Pan1 1School of Pharmacy, Shenyang Pharmaceutical University, Shenyang, People’s Republic of China; 2Qiqihar Medical University, Qiqihar, People’s Republic of China Abstract: The epidermal growth factor receptor (EGFR serves an important function in the proliferation of tumors in humans and is an effective target for the treatment of cancer. In this paper, we studied the targeting characteristics of small peptides (AEYLR, EYINQ, and PDYQQD that were derived from three major autophosphorylation sites of the EGFR C-terminus domain in vitro. These small peptides were labeled with fluorescein isothiocyanate (FITC and used the peptide LARLLT as a positive control, which bound to putative EGFR selected from a virtual peptide library by computer-aided design, and the independent peptide RALEL as a negative control. Analyses with flow cytometry and an internalization assay using NCI-H1299 and K562 with high EGFR and no EGFR expression, respectively, indicated that FITC-AEYLR had high EGFR targeting activity. Biotin-AEYLR that was specifically bound to human EGFR proteins demonstrated a high affinity for human non-small-cell lung tumors. We found that AEYLR peptide-conjugated, nanostructured lipid carriers enhanced specific cellular uptake in vitro during a process that was apparently mediated by tumor cells with high-expression EGFR. Analysis of the MTT assay indicated that the AEYLR peptide did not significantly stimulate or inhibit the growth activity of the cells. These findings suggest that, when mediated by EGFR, AEYLR may be a potentially safe and efficient delivery ligand for targeted chemotherapy, radiotherapy, and gene therapy. Keywords: EGFR, small peptide, tumor targeting, lung cancer, NLC

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

Crystal structure of Middle East respiratory syndrome coronavirus helicase.

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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.

A Tetrameric Peptide Derived from Bovine Lactoferricin Exhibits Specific Cytotoxic Effects against Oral Squamous-Cell Carcinoma Cell Lines

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Víctor A. Solarte

2015-01-01

Full Text Available Several short linear peptides derived from cyclic bovine lactoferricin were synthesized and tested for their cytotoxic effect against the oral cavity squamous-cell carcinoma (OSCC cell lines CAL27 and SCC15. As a control, an immortalized and nontumorigenic cell line, Het-1A, was used. Linear peptides based on the RRWQWR core sequence showed a moderate cytotoxic effect and specificity towards tumorigenic cells. A tetrameric peptide, LfcinB(20–254, containing the RRWQWR motif, exhibited greater cytotoxic activity (>90% in both OSCC cell lines compared to the linear lactoferricin peptide or the lactoferrin protein. Additionally, this tetrameric peptide showed the highest specificity towards tumorigenic cells among the tested peptides. Interestingly, this effect was very fast, with cell shrinkage, severe damage to cell membrane permeability, and lysis within one hour of treatment. Our results are consistent with a necrotic effect rather than an apoptotic one and suggest that this tetrameric peptide could be considered as a new candidate for the therapeutic treatment of OSCC.

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

Bounds for Asian basket options

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Deelstra, Griselda; Diallo, Ibrahima; Vanmaele, Michèle

2008-09-01

In this paper we propose pricing bounds for European-style discrete arithmetic Asian basket options in a Black and Scholes framework. We start from methods used for basket options and Asian options. First, we use the general approach for deriving upper and lower bounds for stop-loss premia of sums of non-independent random variables as in Kaas et al. [Upper and lower bounds for sums of random variables, Insurance Math. Econom. 27 (2000) 151-168] or Dhaene et al. [The concept of comonotonicity in actuarial science and finance: theory, Insurance Math. Econom. 31(1) (2002) 3-33]. We generalize the methods in Deelstra et al. [Pricing of arithmetic basket options by conditioning, Insurance Math. Econom. 34 (2004) 55-57] and Vanmaele et al. [Bounds for the price of discrete sampled arithmetic Asian options, J. Comput. Appl. Math. 185(1) (2006) 51-90]. Afterwards we show how to derive an analytical closed-form expression for a lower bound in the non-comonotonic case. Finally, we derive upper bounds for Asian basket options by applying techniques as in Thompson [Fast narrow bounds on the value of Asian options, Working Paper, University of Cambridge, 1999] and Lord [Partially exact and bounded approximations for arithmetic Asian options, J. Comput. Finance 10 (2) (2006) 1-52]. Numerical results are included and on the basis of our numerical tests, we explain which method we recommend depending on moneyness and time-to-maturity.

Human Platelet-Rich Plasma- and Extracellular Matrix-Derived Peptides Promote Impaired Cutaneous Wound Healing In Vivo

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Demidova-Rice, Tatiana N.; Wolf, Lindsey; Deckenback, Jeffry; Hamblin, Michael R.; Herman, Ira M.

2012-01-01

Previous work in our laboratory has described several pro-angiogenic short peptides derived from endothelial extracellular matrices degraded by bacterial collagenase. Here we tested whether these peptides could stimulate wound healing in vivo. Our experiments demonstrated that a peptide created as combination of fragments of tenascin X and fibrillin 1 (comb1) applied into cranial dermal wounds created in mice treated with cyclophosphamide to impair wound healing, can improve the rate of wound closure. Furthermore, we identify and characterize a novel peptide (UN3) created and modified from two naturally-occurring peptides, which are present in human platelet-rich plasma. In vitro testing of UN3 demonstrates that it causes a 50% increase in endothelial proliferation, 250% increase in angiogenic response and a tripling of epithelial cell migration in response to injury. Results of in vivo experiments where comb1 and UN3 peptides were added together to cranial wounds in cyclophosphamide-treated mice leads to improvement of wound vascularization as shown by an increase of the number of blood vessels present in the wound beds. Application of the peptides markedly promotes cellular responses to injury and essentially restores wound healing dynamics to those of normal, acute wounds in the absence of cyclophosphamide impairment. Our current work is aimed at understanding the mechanisms underlying the stimulatory effects of these peptides as well as identification of the cellular receptors mediating these effects. PMID:22384158

Binding and orientation of fibronectin on polystyrene surfaces using immobilized bacterial adhesin-related peptides.

Science.gov (United States)

Klueh, U; Bryers, J D; Kreutzer, D L

2003-10-01

Fibronectin (FN) is known to bind to bacteria via high affinity receptors on bacterial surfaces known as adhesins. The binding of bacteria to FN is thought to have a key role in foreign device associated infections. For example, previous studies have indicated that Staphylococcus aureus adhesins bind to the 29 kDa NH(3) terminus end of FN, and thereby promote bacteria adherence to surfaces. Recently, the peptide sequences within the S. aureus adhesin molecule that are responsible for FN binding have been identified. Based on these observations, we hypothesize that functional FN can be bound and specifically oriented on polystyrene surfaces using bacterial adhesin-related (BRP-A) peptide. We further hypothesize that monoclonal antibodies that react with specific epitopes on the FN can be used to quantify both FN binding and orientation on these surfaces. Based on this hypothesis, we initiated a systematic investigation of the binding and orientation of FN on polystyrene surfaces using BRP-A peptide. To test this hypothesis, the binding and orientation of the FN to immobilized BRP-A was quantified using (125)I-FN, and monoclonal antibodies. (125)I-FN was used to quantitate FN binding to peptide-coated polystyrene surfaces. The orientation of bound FN was demonstrated by the use of monoclonal antibodies, which are reactive with the amine (N) or carboxyl (C) termini of the FN. The results of our studies demonstrated that when the BRP-A peptide was used to bind FN to surfaces that: 1. functional FN was bound to the peptide; 2. anti-C terminus antibodies bound to the peptide FN; and 3. only limited binding of anti-N terminus antibodies to peptide-bound FN occurred. We believe that the data that indicate an enhanced binding of anti-C antibodies reactive to anti-N antibodies are a result of the FN binding in an oriented manner with the N termini of FN bound tightly to the BRP-A on the polystyrene surface. Copyright 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 36

Destabilization of Human Insulin Fibrils by Peptides of Fruit Bromelain Derived From Ananas comosus (Pineapple).

Science.gov (United States)

Das, Sromona; Bhattacharyya, Debasish

2017-12-01

Deposition of insulin aggregates in human body leads to dysfunctioning of several organs. Effectiveness of fruit bromelain from pineapple in prevention of insulin aggregate was investigated. Proteolyses of bromelain was done as par human digestive system and the pool of small peptides was separated from larger peptides and proteins. Under conditions of growth of insulin aggregates from its monomers, this pool of peptides restricted the reaction upto formation of oligomers of limited size. These peptides also destabilized preformed insulin aggregates to oligomers. These processes were followed fluorimetrically using Thioflavin T and 1-ANS, size-exclusion HPLC, dynamic light scattering, atomic force microscopy, and transmission electron microscopy. Sequences of insulin (A and B chains) and bromelain were aligned using Clustal W software to predict most probable sites of interactions. Synthetic tripeptides corresponding to the hydrophobic interactive sites of bromelain showed disaggregation of insulin suggesting specificity of interactions. The peptides GG and AAA serving as negative controls showed no potency in destabilization of aggregates. Disaggregation potency of the peptides was also observed when insulin was deposited on HepG2 liver cells where no formation of toxic oligomers occurred. Amyloidogenic des-octapeptide (B23-B30 of insulin) incapable of cell signaling showed cytotoxicity similar to insulin. This toxicity could be neutralized by bromelain derived peptides. FT-IR and far-UV circular dichroism analysis indicated that disaggregated insulin had structure distinctly different from that of its hexameric (native) or monomeric states. Based on the stoichiometry of interaction and irreversibility of disaggregation, the mechanism/s of the peptides and insulin interactions has been proposed. J. Cell. Biochem. 118: 4881-4896, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Prediction of antibacterial activity from physicochemical properties of antimicrobial peptides.

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Manuel N Melo

Full Text Available Consensus is gathering that antimicrobial peptides that exert their antibacterial action at the membrane level must reach a local concentration threshold to become active. Studies of peptide interaction with model membranes do identify such disruptive thresholds but demonstrations of the possible correlation of these with the in vivo onset of activity have only recently been proposed. In addition, such thresholds observed in model membranes occur at local peptide concentrations close to full membrane coverage. In this work we fully develop an interaction model of antimicrobial peptides with biological membranes; by exploring the consequences of the underlying partition formalism we arrive at a relationship that provides antibacterial activity prediction from two biophysical parameters: the affinity of the peptide to the membrane and the critical bound peptide to lipid ratio. A straightforward and robust method to implement this relationship, with potential application to high-throughput screening approaches, is presented and tested. In addition, disruptive thresholds in model membranes and the onset of antibacterial peptide activity are shown to occur over the same range of locally bound peptide concentrations (10 to 100 mM, which conciliates the two types of observations.

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

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

The structure of the antimicrobial active center of lactoferricin B bound to sodium dodecyl sulfate micelles.

Science.gov (United States)

Schibli, D J; Hwang, P M; Vogel, H J

1999-03-12

Lactoferricin B (LfcinB) is a 25-residue antimicrobial peptide released from bovine lactoferrin upon pepsin digestion. The antimicrobial center of LfcinB consists of six residues (RRWQWR-NH2), and it possesses similar bactericidal activity to LfcinB. The structure of the six-residue peptide bound to sodium dodecyl sulfate (SDS) micelles has been determined by NMR spectroscopy and molecular dynamics refinement. The peptide adopts a well defined amphipathic structure when bound to SDS micelles with the Trp sidechains separated from the Arg residues. Additional evidence demonstrates that the peptide is oriented in the micelle such that the Trp residues are more deeply buried in the micelle than the Arg and Gln residues.

Diagnostic Methods for Feline Coronavirus: A Review

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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.

Recognition of GPCRs by peptide ligands and membrane compartments theory: structural studies of endogenous peptide hormones in membrane environment.

Science.gov (United States)

Sankararamakrishnan, Ramasubbu

2006-04-01

One of the largest family of cell surface proteins, G-protein coupled receptors (GPCRs) regulate virtually all known physiological processes in mammals. With seven transmembrane segments, they respond to diverse range of extracellular stimuli and represent a major class of drug targets. Peptidergic GPCRs use endogenous peptides as ligands. To understand the mechanism of GPCR activation and rational drug design, knowledge of three-dimensional structure of receptor-ligand complex is important. The endogenous peptide hormones are often short, flexible and completely disordered in aqueous solution. According to "Membrane Compartments Theory", the flexible peptide binds to the membrane in the first step before it recognizes its receptor and the membrane-induced conformation is postulated to bind to the receptor in the second step. Structures of several peptide hormones have been determined in membrane-mimetic medium. In these studies, micelles, reverse micelles and bicelles have been used to mimic the cell membrane environment. Recently, conformations of two peptide hormones have also been studied in receptor-bound form. Membrane environment induces stable secondary structures in flexible peptide ligands and membrane-induced peptide structures have been correlated with their bioactivity. Results of site-directed mutagenesis, spectroscopy and other experimental studies along with the conformations determined in membrane medium have been used to interpret the role of individual residues in the peptide ligand. Structural differences of membrane-bound peptides that belong to the same family but differ in selectivity are likely to explain the mechanism of receptor selectivity and specificity of the ligands. Knowledge of peptide 3D structures in membrane environment has potential applications in rational drug design.

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

Synthesis, Characterization, and Initial Biological Evaluation of [99m Tc]Tc-Tricarbonyl-labeled DPA-α-MSH Peptide Derivatives for Potential Melanoma Imaging.

Science.gov (United States)

Gao, Feng; Sihver, Wiebke; Bergmann, Ralf; Belter, Birgit; Bolzati, Cristina; Salvarese, Nicola; Steinbach, Jörg; Pietzsch, Jens; Pietzsch, Hans-Jürgen

2018-06-06

α-Melanocyte stimulating hormone (α-MSH) derivatives target the melanocortin-1 receptor (MC1R) specifically and selectively. In this study, the α-MSH-derived peptide NAP-NS1 (Nle-Asp-His-d-Phe-Arg-Trp-Gly-NH 2 ) with and without linkers was conjugated with 5-(bis(pyridin-2-ylmethyl)amino)pentanoic acid (DPA-COOH) and labeled with [ 99m Tc]Tc-tricarbonyl by two methods. With the one-pot method the labeling was faster than with the two-pot method, while obtaining similarly high yields. Negligible trans-chelation and high stability in physiological solutions was determined for the [ 99m Tc]Tc-tricarbonyl-peptide conjugates. Coupling an ethylene glycol (EG)-based linker increased the hydrophilicity. The peptide derivatives displayed high binding affinity in murine B16F10 melanoma cells as well as in human MeWo and TXM13 melanoma cell homogenates. Preliminary in vivo studies with one of the [ 99m Tc]Tc-tricarbonyl-peptide conjugates showed good stability in blood and both renal and hepatobiliary excretion. Biodistribution was performed on healthy rats to gain initial insight into the potential relevance of the 99m Tc-labeled peptides for in vivo imaging. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Universal bounds on current fluctuations.

Science.gov (United States)

Pietzonka, Patrick; Barato, Andre C; Seifert, Udo

2016-05-01

For current fluctuations in nonequilibrium steady states of Markovian processes, we derive four different universal bounds valid beyond the Gaussian regime. Different variants of these bounds apply to either the entropy change or any individual current, e.g., the rate of substrate consumption in a chemical reaction or the electron current in an electronic device. The bounds vary with respect to their degree of universality and tightness. A universal parabolic bound on the generating function of an arbitrary current depends solely on the average entropy production. A second, stronger bound requires knowledge both of the thermodynamic forces that drive the system and of the topology of the network of states. These two bounds are conjectures based on extensive numerics. An exponential bound that depends only on the average entropy production and the average number of transitions per time is rigorously proved. This bound has no obvious relation to the parabolic bound but it is typically tighter further away from equilibrium. An asymptotic bound that depends on the specific transition rates and becomes tight for large fluctuations is also derived. This bound allows for the prediction of the asymptotic growth of the generating function. Even though our results are restricted to networks with a finite number of states, we show that the parabolic bound is also valid for three paradigmatic examples of driven diffusive systems for which the generating function can be calculated using the additivity principle. Our bounds provide a general class of constraints for nonequilibrium systems.

Milk-derived proteins and peptides in clinical trials

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Jolanta Artym

2013-08-01

Full Text Available Clinical trials are reviewed, involving proteins and peptides derived from milk (predominantly bovine, with the exception of lactoferrin, which will be the subject of another article. The most explored milk fraction is α-lactalbumin (LA, which is often applied with glycomacropeptide (GMP – a casein degradation product. These milk constituents are used in health-promoting infant and adult formulae as well as in a modified form (HAMLET to treat cancer. Lactoperoxidase (LCP is used as an additive to mouth hygiene products and as a salivary substitute. Casein derivatives are applied, in addition, in the dry mouth syndrome. On the other hand, casein hydrolysates, containing active tripeptides, found application in hypertension and in type 2 diabetes. Lysozyme is routinely used for food conservation and in pharmaceutical products. It was successfully used in premature infants with concomitant diseases to improve health parameters. When used as prophylaxis in patients with scheduled surgery, it significantly reduced the incidence of hepatitis resulting from blood transfusion. Lysozyme was also used in infected children as an antimicrobial agent showing synergistic effects in combination with different antibiotics. Proline-rich polypeptide (PRP was introduced to therapy of Alzheimer’s disease patients. The therapeutic value of PRP was proved in several clinical trials and supported by studies on its mechanism of action. Concentrated immunoglobulin preparations from colostrum and milk of hyperimmunized cows showed efficacy in prevention of infections by bacteria, viruses and protozoa. A nutrition formula with milk-derived TGF-β2 (Modulen IBD® found application in treatment of pediatric Crohn’s disease. In conclusion, the preparations containing milk-derived products are safe and effective measures in prevention and treatment of infections as well as autoimmune and neoplastic diseases.

Laminin Peptide-Immobilized Hydrogels Modulate Valve Endothelial Cell Hemostatic Regulation.

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Liezl Rae Balaoing

Full Text Available Valve endothelial cells (VEC have unique phenotypic responses relative to other types of vascular endothelial cells and have highly sensitive hemostatic functions affected by changes in valve tissues. Furthermore, effects of environmental factors on VEC hemostatic function has not been characterized. This work used a poly(ethylene glycol diacrylate (PEGDA hydrogel platform to evaluate the effects of substrate stiffness and cell adhesive ligands on VEC phenotype and expression of hemostatic genes. Hydrogels of molecular weights (MWs 3.4, 8, and 20 kDa were polymerized into platforms of different rigidities and thiol-modified cell adhesive peptides were covalently bound to acrylate groups on the hydrogel surfaces. The peptide RKRLQVQLSIRT (RKR is a syndecan-1 binding ligand derived from laminin, a trimeric protein and a basement membrane matrix component. Conversely, RGDS is an integrin binding peptide found in many extracellular matrix (ECM proteins including fibronectin, fibrinogen, and von Willebrand factor (VWF. VECs adhered to and formed a stable monolayer on all RKR-coated hydrogel-MW combinations. RGDS-coated platforms supported VEC adhesion and growth on RGDS-3.4 kDa and RGDS-8 kDa hydrogels. VECs cultured on the softer RKR-8 kDa and RKR-20 kDa hydrogel platforms had significantly higher gene expression for all anti-thrombotic (ADAMTS-13, tissue factor pathway inhibitor, and tissue plasminogen activator and thrombotic (VWF, tissue factor, and P-selectin proteins than VECs cultured on RGDS-coated hydrogels and tissue culture polystyrene controls. Stimulated VECs promoted greater platelet adhesion than non-stimulated VECs on their respective culture condition; yet stimulated VECs on RGDS-3.4 kDa gels were not as responsive to stimulation relative to the RKR-gel groups. Thus, the syndecan binding, laminin-derived peptide promoted stable VEC adhesion on the softer hydrogels and maintained VEC phenotype and natural hemostatic function. In

Antimelanoma CTL recognizes peptides derived from an ORF transcribed from the antisense strand of the 3′ untranslated region of TRIT1

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Rolf K Swoboda

2014-01-01

Full Text Available Noncoding regions of the genome play an important role in tumorigenesis of cancer. Using expression cloning, we have identified a cytotoxic T lymphocyte (CTL–defined antigen that recognizes a protein sequence derived from an open reading frame transcribed from the reverse strand in the 3′ untranslated region of tRNA isopentenyltransferase 1 (TRIT1. A peptide derived from this open reading frame (ORF sequence and predicted to bind to HLA-B57, sensitized HLA-B57+ tumor cells to lysis by CTL793. The peptide also induced a CTL response in peripheral blood mononuclear cells (PBMC of patient 793 and in two other melanoma patients. The CTL lysed peptide-pulsed HLA-B57+ target cells and melanoma cells with endogenous antigen expression. The recognition of this antigen is not limited to HLA-B57-restricted CTLs. An HLA-A2 peptide derived from the ORF was able to induce CTLs in PBMC of 2 HLA-A2+ patients. This study describes for the first time a CTL-defined melanoma antigen that is derived from an ORF on the reverse strand of the putative tumor suppressor gene TRIT1. This antigen has potential use as a vaccine or its ability to induce CTLs in vitro could be used as a predictive biomarker.

ProSAAS-derived peptides are differentially processed and sorted in mouse brain and AtT-20 cells.

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Jonathan H Wardman

Full Text Available ProSAAS is the precursor for some of the most abundant peptides found in mouse brain and other tissues, including peptides named SAAS, PEN, and LEN. Both SAAS and LEN are found in big and little forms due to differential processing. Initial processing of proSAAS is mediated by furin (and/or furin-like enzymes and carboxypeptidase D, while the smaller forms are generated by secretory granule prohormone convertases and carboxypeptidase E. In mouse hypothalamus, PEN and big LEN colocalize with neuropeptide Y. In the present study, little LEN and SAAS were detected in mouse hypothalamus but not in cell bodies of neuropeptide Y-expressing neurons. PEN and big LEN show substantial colocalization in hypothalamus, but big LEN and little LEN do not. An antiserum to SAAS that detects both big and little forms of this peptide did not show substantial colocalization with PEN or big LEN. To further study this, the AtT-20 cells mouse pituitary corticotrophic cell line was transfected with rat proSAAS and the distribution of peptides examined. As found in mouse hypothalamus, only some of the proSAAS-derived peptides colocalized with each other in AtT-20 cells. The two sites within proSAAS that are known to be efficiently cleaved by furin were altered by site-directed mutagenesis to convert the P4 Arg into Lys; this change converts the sequences from furin consensus sites into prohormone convertase consensus sites. Upon expression of the mutated form of proSAAS in AtT-20 cells, there was significantly more colocalization of proSAAS-derived peptides PEN and SAAS. Taken together, these results indicate that proSAAS is initially cleaved in the Golgi or trans-Golgi network by furin and/or furin-like enzymes and the resulting fragments are sorted into distinct vesicles and further processed by additional enzymes into the mature peptides.

Synthetic Peptides Derived from Bovine Lactoferricin Exhibit Antimicrobial Activity against E. coli ATCC 11775, S. maltophilia ATCC 13636 and S. enteritidis ATCC 13076.

Science.gov (United States)

Huertas Méndez, Nataly De Jesús; Vargas Casanova, Yerly; Gómez Chimbi, Anyelith Katherine; Hernández, Edith; Leal Castro, Aura Lucia; Melo Diaz, Javier Mauricio; Rivera Monroy, Zuly Jenny; García Castañeda, Javier Eduardo

2017-03-12

Linear, dimeric, tetrameric, and cyclic peptides derived from lactoferricin B-containing non-natural amino acids and the RWQWR motif were synthesized, purified, and characterized using RP-HPLC, MALDI-TOF mass spectrometry, and circular dichroism. The antibacterial activity of peptides against Escherichia coli ATCC 11775, Stenotrophomonas maltophilia ATCC 13636, and Salmonella enteritidis ATCC 13076 was evaluated. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. The synthetic bovine lactoferricin exhibited antibacterial activity against E. coli ATCC 11775 and S. enteritidis ATCC 13076. The dimeric peptide (RRWQWR)₂K-Ahx exhibited the highest antibacterial activity against the tested bacterial strain. The monomeric, cyclic, tetrameric, and palindromic peptides containing the RWQWR motif exhibited high and specific activity against E. coli ATCC 11775. The results suggest that short peptides derived from lactoferricin B could be considered as potential candidates for the development of antibacterial agents against infections caused by E. coli .

NMR spectroscopic studies of a TAT-derived model peptide in imidazolium-based ILs: influence on chemical shifts and the cis/trans equilibrium state.

Science.gov (United States)

Wiedemann, Christoph; Ohlenschläger, Oliver; Mrestani-Klaus, Carmen; Bordusa, Frank

2017-09-13

NMR spectroscopy was used to study systematically the impact of imidazolium-based ionic liquid (IL) solutions on a TAT-derived model peptide containing Xaa-Pro peptide bonds. The selected IL anions cover a wide range of the Hofmeister series of ions. Based on highly resolved one- and two-dimensional NMR spectra individual 1 H and 13 C peptide chemical shift differences were analysed and a classification of IL anions according to the Hofmeister series was derived. The observed chemical shift changes indicate significant interactions between the peptide and the ILs. In addition, we examined the impact of different ILs towards the cis/trans equilibrium state of the Xaa-Pro peptide bonds. In this context, the IL cations appear to be of exceptional importance for inducing an alteration of the native cis/trans equilibrium state of Xaa-Pro bonds in favour of the trans-isomers.

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.

Presence of chromogranin-derived antimicrobial peptides in plasma during coronary artery bypass surgery and evidence of an immune origin of these peptides.

Science.gov (United States)

Tasiemski, Aurélie; Hammad, Hamida; Vandenbulcke, Franck; Breton, Christophe; Bilfinger, Thomas J; Pestel, Joel; Salzet, Michel

2002-07-15

Chromogranin A (CGA) and chromogranin B (CGB) are acidic proteins stored in secretory organelles of endocrine cells and neurons. In addition to their roles as helper proteins in the packaging of peptides, they may serve as prohormones to generate biologically active peptides such as vasostatin-1 and secretolytin. These molecules derived from CGA and CGB, respectively, possess antimicrobial properties. The present study demonstrates that plasmatic levels of both vasostatin-1 and secretolytin increase during surgery in patients undergoing cardiopulmonary bypass (CPB). Vasostatin-1 and secretolytin, initially present in plasma at low levels, are released just after skin incision. Consequently, they can be added to enkelytin, an antibacterial peptide derived from proenkephalin A, for the panoply of components acting as a first protective barrier against hypothetical invasion of pathogens, which may occur during surgery. CGA and CGB, more commonly viewed as markers for endocrine and neuronal cells, were also found to have an immune origin. RNA messengers coding for CGB were amplified by reverse transcription-polymerase chain reaction in human monocytes, and immunocytochemical analysis by confocal microscopy revealed the presence of CGA or CGB or both in monocytes and neutrophils. A combination of techniques including confocal microscopic analysis, mass spectrometry measurement, and antibacterial tests allowed for the identification of the positive role of interleukin 6 (IL-6) in the secretolytin release from monocytes in vitro. Because IL-6 release is known to be strongly enhanced during CPB, we suggest a possible relationship between IL-6 and the increased level of secretolytin in patients undergoing CPB.

Pentastatin-1, a collagen IV derived 20-mer peptide, suppresses tumor growth in a small cell lung cancer xenograft model.

Science.gov (United States)

Koskimaki, Jacob E; Karagiannis, Emmanouil D; Tang, Benjamin C; Hammers, Hans; Watkins, D Neil; Pili, Roberto; Popel, Aleksander S

2010-02-01

Angiogenesis is the formation of neovasculature from a pre-existing vascular network. Progression of solid tumors including lung cancer is angiogenesis-dependent. We previously introduced a bioinformatics-based methodology to identify endogenous anti-angiogenic peptide sequences, and validated these predictions in vitro in human umbilical vein endothelial cell (HUVEC) proliferation and migration assays. One family of peptides with high activity is derived from the alpha-fibrils of type IV collagen. Based on the results from the in vitro screening, we have evaluated the ability of a 20 amino acid peptide derived from the alpha5 fibril of type IV collagen, pentastatin-1, to suppress vessel growth in an angioreactor-based directed in vivo angiogenesis assay (DIVAA). In addition, pentastatin-1 suppressed tumor growth with intraperitoneal peptide administration in a small cell lung cancer (SCLC) xenograft model in nude mice using the NCI-H82 human cancer cell line. Pentastatin-1 decreased the invasion of vessels into angioreactors in vivo in a dose dependent manner. The peptide also decreased the rate of tumor growth and microvascular density in vivo in a small cell lung cancer xenograft model. The peptide treatment significantly decreased the invasion of microvessels in angioreactors and the rate of tumor growth in the xenograft model, indicating potential treatment for angiogenesis-dependent disease, and for translational development as a therapeutic agent for lung cancer.

Pentastatin-1, a collagen IV derived 20-mer peptide, suppresses tumor growth in a small cell lung cancer xenograft model

International Nuclear Information System (INIS)

Koskimaki, Jacob E; Karagiannis, Emmanouil D; Tang, Benjamin C; Hammers, Hans; Watkins, D Neil; Pili, Roberto; Popel, Aleksander S

2010-01-01

Angiogenesis is the formation of neovasculature from a pre-existing vascular network. Progression of solid tumors including lung cancer is angiogenesis-dependent. We previously introduced a bioinformatics-based methodology to identify endogenous anti-angiogenic peptide sequences, and validated these predictions in vitro in human umbilical vein endothelial cell (HUVEC) proliferation and migration assays. One family of peptides with high activity is derived from the α-fibrils of type IV collagen. Based on the results from the in vitro screening, we have evaluated the ability of a 20 amino acid peptide derived from the α5 fibril of type IV collagen, pentastatin-1, to suppress vessel growth in an angioreactor-based directed in vivo angiogenesis assay (DIVAA). In addition, pentastatin-1 suppressed tumor growth with intraperitoneal peptide administration in a small cell lung cancer (SCLC) xenograft model in nude mice using the NCI-H82 human cancer cell line. Pentastatin-1 decreased the invasion of vessels into angioreactors in vivo in a dose dependent manner. The peptide also decreased the rate of tumor growth and microvascular density in vivo in a small cell lung cancer xenograft model. The peptide treatment significantly decreased the invasion of microvessels in angioreactors and the rate of tumor growth in the xenograft model, indicating potential treatment for angiogenesis-dependent disease, and for translational development as a therapeutic agent for lung cancer

Conformational analysis of Infectious bursal disease virus (IBDV derived cell penetrating peptide (CPP analogs

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Vinay G. Joshi

2013-12-01

Full Text Available Aim: This study was designed to develop peptide analogs of Infectious Bursal Disease (IBD virus VP5 protein segment having cell penetrating ability to improve their interaction with cargo molecule (Nucleic acid without affecting the backbone conformation. Materials and Methods: IBDV VP5 protein segment designated as RATH peptide were synthesized using solid phase peptide synthesis and their solution conformation was elucidated using CD spectroscopy in polar (water and apolar (TFE solvents. Cell penetrating ability of RATH-CONH2 was observed using FITC labeled peptide internalization in to HeLa cells under fluorescent microscopy. The efficacy of RATH analog interactions with nucleic acids was evaluated using FITC labeled oligonucleotides by fluorescence spectroscopy and plasmid constructs in gel retardation assay. Results: CD spectra of RATH analogs in water and apolar trifluroethanol (TFE helped to compare their secondary structures which were almost similar with dominant beta conformations suggesting successful induction of positive charge in the analogs without affecting back bone conformation of CPP designed. Cell penetrating ability of RATH CONH2 in HeLa cell was more than 90%. The fluorescence spectroscopy and plasmid constructs in gel retardation assay demonstrated successful interaction of amide analogs with nucleic acid. Conclusion: Intentional changes made in IBDV derived peptide RATH COOH to RATH CONH2 did not showed major changes in backbone conformation and such modifications may help to improve the cationic charge in most CPPs to interact with nucleic acid. [Vet World 2013; 6(6.000: 307-312

In Vivo Efficacy of Measles Virus Fusion Protein-Derived Peptides Is Modulated by the Properties of Self-Assembly and Membrane Residence

Science.gov (United States)

Figueira, T. N.; Palermo, L. M.; Veiga, A. S.; Huey, D.; Alabi, C. A.; Santos, N. C.; Welsch, J. C.; Mathieu, C.; Niewiesk, S.; Moscona, A.

2016-01-01

ABSTRACT Measles virus (MV) infection is undergoing resurgence and remains one of the leading causes of death among young children worldwide despite the availability of an effective measles vaccine. MV infects its target cells by coordinated action of the MV hemagglutinin (H) and fusion (F) envelope glycoproteins; upon receptor engagement by H, the prefusion F undergoes a structural transition, extending and inserting into the target cell membrane and then refolding into a postfusion structure that fuses the viral and cell membranes. By interfering with this structural transition of F, peptides derived from the heptad repeat (HR) regions of F can inhibit MV infection at the entry stage. In previous work, we have generated potent MV fusion inhibitors by dimerizing the F-derived peptides and conjugating them to cholesterol. We have shown that prophylactic intranasal administration of our lead fusion inhibitor efficiently protects from MV infection in vivo. We show here that peptides tagged with lipophilic moieties self-assemble into nanoparticles until they reach the target cells, where they are integrated into cell membranes. The self-assembly feature enhances biodistribution and the half-life of the peptides, while integration into the target cell membrane increases fusion inhibitor potency. These factors together modulate in vivo efficacy. The results suggest a new framework for developing effective fusion inhibitory peptides. IMPORTANCE Measles virus (MV) infection causes an acute illness that may be associated with infection of the central nervous system (CNS) and severe neurological disease. No specific treatment is available. We have shown that fusion-inhibitory peptides delivered intranasally provide effective prophylaxis against MV infection. We show here that specific biophysical properties regulate the in vivo efficacy of MV F-derived peptides. PMID:27733647

ProSAAS-derived peptides are regulated by cocaine and are required for sensitization to the locomotor effects of cocaine.

Science.gov (United States)

Berezniuk, Iryna; Rodriguiz, Ramona M; Zee, Michael L; Marcus, David J; Pintar, John; Morgan, Daniel J; Wetsel, William C; Fricker, Lloyd D

2017-11-01

To identify neuropeptides that are regulated by cocaine, we used a quantitative peptidomic technique to examine the relative levels of neuropeptides in several regions of mouse brain following daily intraperitoneal administration of 10 mg/kg cocaine or saline for 7 days. A total of 102 distinct peptides were identified in one or more of the following brain regions: nucleus accumbens, caudate putamen, frontal cortex, and ventral tegmental area. None of the peptides detected in the caudate putamen or frontal cortex were altered by cocaine administration. Three peptides in the nucleus accumbens and seven peptides in the ventral tegmental area were significantly decreased in cocaine-treated mice. Five of these ten peptides are derived from proSAAS, a secretory pathway protein and neuropeptide precursor. To investigate whether proSAAS peptides contribute to the physiological effects of psychostimulants, we examined acute responses to cocaine and amphetamine in the open field with wild-type (WT) and proSAAS knockout (KO) mice. Locomotion was stimulated more robustly in the WT compared to mutant mice for both psychostimulants. Behavioral sensitization to amphetamine was not maintained in proSAAS KO mice and these mutants failed to sensitize to cocaine. To determine whether the rewarding effects of cocaine were altered, mice were tested in conditioned place preference (CPP). Both WT and proSAAS KO mice showed dose-dependent CPP to cocaine that was not distinguished by genotype. Taken together, these results suggest that proSAAS-derived peptides contribute differentially to the behavioral sensitization to psychostimulants, while the rewarding effects of cocaine appear intact in mice lacking proSAAS. © 2017 International Society for Neurochemistry.

Peptide array-based screening of human mesenchymal stem cell-adhesive peptides derived from fibronectin type III domain

International Nuclear Information System (INIS)

Okochi, Mina; Nomura, Shigeyuki; Kaga, Chiaki; Honda, Hiroyuki

2008-01-01

Human mesenchymal stem cell-adhesive peptides were screened based on the amino acid sequence of fibronectin type III domain 8-11 (FN-III 8-11 ) using a peptide array synthesized by the Fmoc-chemistry. Using hexameric peptide library of FN-III 8-11 scan, we identified the ALNGR (Ala-Leu-Asn-Gly-Arg) peptide that induced cell adhesion as well as RGDS (Arg-Gly-Asp-Ser) peptide. After incubation for 2 h, approximately 68% of inoculated cells adhere to the ALNGR peptide disk. Adhesion inhibition assay with integrin antibodies showed that the ALNGR peptide interacts with integrin β1 but not with αvβ3, indicating that the receptors for ALNGR are different from RGDS. Additionally, the ALNGR peptide expressed cell specificities for adhesion: cell adhesion was promoted for fibroblasts but not for keratinocytes or endotherial cells. The ALNGR peptide induced cell adhesion and promoted cell proliferation without changing its property. It is therefore useful for the construction of functional biomaterials

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.

Photon virtual bound state

International Nuclear Information System (INIS)

Inoue, J.; Ohtaka, K.

2004-01-01

We study virtual bound states in photonics, which are a vectorial extension of electron virtual bound states. The condition for these states is derived. It is found that the Mie resonant state which satisfies the condition that the size parameter is less than the angular momentum should be interpreted as a photon virtual bound state. In order to confirm the validity of the concept, we compare the photonic density of states, the width of which represents the lifetime of the photon virtual bound states, with numerical results

Crystallization and preliminary X-ray crystallographic analysis of peptide deformylase (PDF) from Bacillus cereus in ligand-free and actinonin-bound forms.

Science.gov (United States)

Park, Joon Kyu; Moon, Jin Ho; Kim, Jae-Hong; Kim, Eunice EunKyeong

2005-01-01

In bacteria, protein expression initiates with an N-formyl group and this needs to be removed in order to ensure proper bacterial growth. These formylation and deformylation processes are unique to eubacteria; therefore, inhibition of these would provide a novel antibacterial therapy. Deformylation is carried out by peptide deformylase (PDF). PDF from Bacillus cereus, one of the major pathogenic bacteria, was cloned into expression plasmid pET-28a (Novagen), overexpressed in Escherichia coli BL21 (DE3) and purified to high quality. Crystals have been obtained of both ligand-free PDF and PDF to which actinonin, a highly potent naturally occurring inhibitor, is bound. Both crystals belong to space group P2(1)2(1)2(1), with unit-cell parameters a = 42.72, b = 44.04, c = 85.19 A and a = 41.31, b = 44.56, c = 84.47 A, respectively. Diffraction data were collected to 1.7 A resolution for the inhibitor-free crystals and to 2.0 A resolution for the actinonin-bound crystals.

Proteomics shows Hsp70 does not bind peptide sequences indiscriminately in vivo

International Nuclear Information System (INIS)

Grossmann, Michael E.; Madden, Benjamin J.; Gao, Fan; Pang, Yuan-Ping; Carpenter, John E.; McCormick, Daniel; Young, Charles Y.F.

2004-01-01

Heat shock protein 70 (Hsp70) binds peptide and has several functions that include protein folding, protein trafficking, and involvement with immune function. However, endogenous Hsp70-binding peptides had not previously been identified. Therefore, we eluted and identified several hundred endogenously bound peptides from Hsp70 using liquid chromatography ion trap mass spectrophotometry (LC-ITMS). Our work shows that the peptides are capable of binding Hsp70 as previously described. They are generally 8-26 amino acids in length and correspond to specific regions of many proteins. Through computationally assisted analysis of peptides eluted from Hsp70 we determined variable amino acid sequences, including a 5 amino acid core sequence that Hsp70 favorably binds. We also developed a computer algorithm that predicts Hsp70 binding within proteins. This work helps to define what peptides are bound by Hsp70 in vivo and suggests that Hsp70 facilitates peptide selection by aiding a funneling mechanism that is flexible but allows only a limited number of peptides to be processed

Penilumamide, a novel lumazine peptide isolated from the marine-derived fungus, Penicillium sp. CNL-338.

Science.gov (United States)

Meyer, Sven W; Mordhorst, Thorsten F; Lee, Choonghwan; Jensen, Paul R; Fenical, William; Köck, Matthias

2010-05-07

A novel lumazine peptide, penilumamide (1), was isolated from the fermentation broth of a marine-derived fungal strain, identified as Penicillium sp. (strain CNL-338) and the structure of the new metabolite was determined by analysis of ESI-TOF MS data combined with 1D and 2D NMR experiments.

Uniform bounds for Black--Scholes implied volatility

OpenAIRE

Tehranchi, Michael R.

2015-01-01

In this note, Black--Scholes implied volatility is expressed in terms of various optimisation problems. From these representations, upper and lower bounds are derived which hold uniformly across moneyness and call price. Various symmetries of the Black--Scholes formula are exploited to derive new bounds from old. These bounds are used to reprove asymptotic formulae for implied volatility at extreme strikes and/or maturities.

Molecular basis for endotoxin neutralization by amphipathic peptides derived from the alpha-helical cationic core-region of NK-lysin.

Science.gov (United States)

Brandenburg, Klaus; Garidel, Patrick; Fukuoka, Satoshi; Howe, Jörg; Koch, Michel H J; Gutsmann, Thomas; Andrä, Jörg

2010-08-01

An analysis of the interaction of the NK-lysin derived peptide NK-2 and of analogs thereof with bacterial lipopolysaccharide (LPS, endotoxin) was performed to determine the most important biophysical parameters for an effective LPS neutralization. We used microcalorimetry, FTIR spectroscopy, Zeta potential measurements, and small-angle X-ray scattering to analyze the peptide:LPS binding enthalpy, the accessible LPS surface charge, the fluidity of the LPS hydrocarbon chains, their phase transition enthalpy change, the aggregate structure of LPS, and how these parameters are modulated by the peptides. We conclude that (i) a high peptide:LPS binding affinity, which is facilitated by electrostatic and hydrophobic interactions and which leads to a positive Zeta potential, (ii) the formation of peptide-enriched domains, which destabilize the lipid packing, demonstrated by a drastic decrease of phase transition enthalpy change of LPS, and (iii) the multilamellarization of the LPS aggregate structure are crucial for an effective endotoxin neutralization by cationic peptides.

Peptide YY receptors in the brain

International Nuclear Information System (INIS)

Inui, A.; Oya, M.; Okita, M.

1988-01-01

Radiolabelled ligand binding studies demonstrated that specific receptors for peptide YY are present in the porcine as well as the canine brains. Peptide YY was bound to brain tissue membranes via high-affinity (dissociation constant, 1.39 X 10(-10)M) and low-affinity (dissociation constant, 3.72 X 10(-8)M) components. The binding sites showed a high specificity for peptide YY and neuropeptide Y, but not for pancreatic polypeptide or structurally unrelated peptides. The specific activity of peptide YY binding was highest in the hippocampus, followed by the pituitary gland, the hypothalamus, and the amygdala of the porcine brain, this pattern being similarly observed in the canine brain. The results suggest that peptide YY and neuropeptide Y may regulate the function of these regions of the brain through interaction with a common receptor site

Synthetic Peptides Derived from Bovine Lactoferricin Exhibit Antimicrobial Activity against E. coli ATCC 11775, S. maltophilia ATCC 13636 and S. enteritidis ATCC 13076

Directory of Open Access Journals (Sweden)

Nataly De Jesús Huertas Méndez

2017-03-01

Full Text Available Linear, dimeric, tetrameric, and cyclic peptides derived from lactoferricin B–containing non-natural amino acids and the RWQWR motif were synthesized, purified, and characterized using RP-HPLC, MALDI-TOF mass spectrometry, and circular dichroism. The antibacterial activity of peptides against Escherichia coli ATCC 11775, Stenotrophomonas maltophilia ATCC 13636, and Salmonella enteritidis ATCC 13076 was evaluated. The minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC were determined. The synthetic bovine lactoferricin exhibited antibacterial activity against E. coli ATCC 11775 and S. enteritidis ATCC 13076. The dimeric peptide (RRWQWR2K-Ahx exhibited the highest antibacterial activity against the tested bacterial strain. The monomeric, cyclic, tetrameric, and palindromic peptides containing the RWQWR motif exhibited high and specific activity against E. coli ATCC 11775. The results suggest that short peptides derived from lactoferricin B could be considered as potential candidates for the development of antibacterial agents against infections caused by E. coli.

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

Short Peptides Enhance Single Cell Adhesion and Viability onMicroarrays

Energy Technology Data Exchange (ETDEWEB)

Veiseh, Mandana; Veiseh, Omid; Martin, Michael C.; Asphahani,Fareid; Zhang, Miqin

2007-01-19

Single cell patterning holds important implications forbiology, biochemistry, biotechnology, medicine, and bioinformatics. Thechallenge for single cell patterning is to produce small islands hostingonly single cells and retaining their viability for a prolonged period oftime. This study demonstrated a surface engineering approach that uses acovalently bound short peptide as a mediator to pattern cells withimproved single cell adhesion and prolonged cellular viabilityon goldpatterned SiO2 substrates. The underlying hypothesis is that celladhesion is regulated bythe type, availability, and stability ofeffective cell adhesion peptides, and thus covalently bound shortpeptides would promote cell spreading and, thus, single cell adhesion andviability. The effectiveness of this approach and the underlyingmechanism for the increased probability of single cell adhesion andprolonged cell viability by short peptides were studied by comparingcellular behavior of human umbilical cord vein endothelial cells on threemodelsurfaces whose gold electrodes were immobilized with fibronectin,physically adsorbed Arg-Glu-Asp-Val-Tyr, and covalently boundLys-Arg-Glu-Asp-Val-Tyr, respectively. The surface chemistry and bindingproperties were characterized by reflectance Fourier transform infraredspectroscopy. Both short peptides were superior to fibronectin inproducing adhesion of only single cells, whereas the covalently boundpeptide also reduced apoptosis and necrosisof adhered cells. Controllingcell spreading by peptide binding domains to regulate apoptosis andviability represents a fundamental mechanism in cell-materialsinteraction and provides an effective strategy in engineering arrays ofsingle cells.

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

Analysis of the antimicrobial activities of a chemokine-derived peptide (CDAP-4) on Pseudomonas aeruginosa

International Nuclear Information System (INIS)

Martinez-Becerra, Francisco; Silva, Daniel-Adriano; Dominguez-Ramirez, Lenin; Mendoza-Hernandez, Guillermo; Lopez-Vidal, Yolanda; Soldevila, Gloria; Garcia-Zepeda, Eduardo A.

2007-01-01

Chemokines are key molecules involved in the control of leukocyte trafficking. Recently, a novel function as antimicrobial proteins has been described. CCL13 is the only member of the MCP chemokine subfamily displaying antimicrobial activity. To determine Key residues involved in its antimicrobial activity, CCL13 derived peptides were synthesized and tested against several bacterial strains, including Pseudomonas aeruginosa. One of these peptides, corresponding to the C-terminal region of CCL13 (CDAP-4) displayed good antimicrobial activity. Electron microscopy studies revealed remarkable morphological changes after CDAP-4 treatment. By computer modeling, CDAP-4 in α helical configuration generated a positive electrostatic potential that extended beyond the surface of the molecule. This feature is similar to other antimicrobial peptides. Altogether, these findings indicate that the antimicrobial activity was displayed by CCL13 resides to some extent at the C-terminal region. Furthermore, CDAP-4 could be considered a good antimicrobial candidate with a potential use against pathogens including P. aeruginosa

Analysis and Evaluation of the Inhibitory Mechanism of a Novel Angiotensin-I-Converting Enzyme Inhibitory Peptide Derived from Casein Hydrolysate.

Science.gov (United States)

Tu, Maolin; Liu, Hanxiong; Zhang, Ruyi; Chen, Hui; Mao, Fengjiao; Cheng, Shuzhen; Lu, Weihong; Du, Ming

2018-04-25

Casein hydrolysates exert various biological activities, and the responsible functional peptides are being identified from them continuously. In this study, the tryptic casein hydrolysate was fractionated by an ultrafiltration membrane (3 kDa), and the peptides were identified by capillary electrophoresis-quadrupole-time-of-flight-tandem mass spectrometry. Meanwhile, in silico methods were used to analyze the toxicity, solubility, stability, and affinity between the peptides and angiotensin-I-converting enzyme (ACE). Finally, a new angiotensin-I-converting enzyme inhibitory (ACEI) peptide, EKVNELSK, derived from α s1 -casein (fragment 35-42) was screened. The half maximal inhibitory concentration value of the peptide is 5.998 mM, which was determined by a high-performance liquid chromatography method. The Lineweaver-Burk plot indicated that this peptide is a mixed-type inhibitor against ACE. Moreover, Discovery Studio 2017 R2 software was adopted to perform molecular docking to propose the potential mechanisms underlying the ACEI activity of the peptide. These results indicated that EKVNELSK is a new ACEI peptide identified from casein hydrolysate.

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

Peptide and Peptide-Dependent Motions in MHC Proteins: Immunological Implications and Biophysical Underpinnings

Directory of Open Access Journals (Sweden)

Cory M. Ayres

2017-08-01

Full Text Available Structural biology of peptides presented by class I and class II MHC proteins has transformed immunology, impacting our understanding of fundamental immune mechanisms and allowing researchers to rationalize immunogenicity and design novel vaccines. However, proteins are not static structures as often inferred from crystallographic structures. Their components move and breathe individually and collectively over a range of timescales. Peptides bound within MHC peptide-binding grooves are no exception and their motions have been shown to impact recognition by T cell and other receptors in ways that influence function. Furthermore, peptides tune the motions of MHC proteins themselves, which impacts recognition of peptide/MHC complexes by other proteins. Here, we review the motional properties of peptides in MHC binding grooves and discuss how peptide properties can influence MHC motions. We briefly review theoretical concepts about protein motion and highlight key data that illustrate immunological consequences. We focus primarily on class I systems due to greater availability of data, but segue into class II systems as the concepts and consequences overlap. We suggest that characterization of the dynamic “energy landscapes” of peptide/MHC complexes and the resulting functional consequences is one of the next frontiers in structural immunology.

Cleavage specificity analysis of six type II transmembrane serine proteases (TTSPs using PICS with proteome-derived peptide libraries.

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Olivier Barré

Full Text Available Type II transmembrane serine proteases (TTSPs are a family of cell membrane tethered serine proteases with unclear roles as their cleavage site specificities and substrate degradomes have not been fully elucidated. Indeed just 52 cleavage sites are annotated in MEROPS, the database of proteases, their substrates and inhibitors.To profile the active site specificities of the TTSPs, we applied Proteomic Identification of protease Cleavage Sites (PICS. Human proteome-derived database searchable peptide libraries were assayed with six human TTSPs (matriptase, matriptase-2, matriptase-3, HAT, DESC and hepsin to simultaneously determine sequence preferences on the N-terminal non-prime (P and C-terminal prime (P' sides of the scissile bond. Prime-side cleavage products were isolated following biotinylation and identified by tandem mass spectrometry. The corresponding non-prime side sequences were derived from human proteome databases using bioinformatics. Sequencing of 2,405 individual cleaved peptides allowed for the development of the family consensus protease cleavage site specificity revealing a strong specificity for arginine in the P1 position and surprisingly a lysine in P1' position. TTSP cleavage between R↓K was confirmed using synthetic peptides. By parsing through known substrates and known structures of TTSP catalytic domains, and by modeling the remainder, structural explanations for this strong specificity were derived.Degradomics analysis of 2,405 cleavage sites revealed a similar and characteristic TTSP family specificity at the P1 and P1' positions for arginine and lysine in unfolded peptides. The prime side is important for cleavage specificity, thus making these proteases unusual within the tryptic-enzyme class that generally has overriding non-prime side specificity.

Structure–activity relationships of the human prothrombin kringle-2 peptide derivative NSA9: anti-proliferative activity and cellular internalization

OpenAIRE

Hwang, Hyun Sook; Kim, Dong Won; Kim, Soung Soo

2006-01-01

The human prothrombin kringle-2 protein inhibits angiogenesis and LLC (Lewis lung carcinoma) growth and metastasis in mice. Additionally, the NSA9 peptide (NSAVQLVEN) derived from human prothrombin kringle-2 has been reported to inhibit the proliferation of BCE (bovine capillary endothelial) cells and CAM (chorioallantoic membrane) angiogenesis. In the present study, we examined the structure–activity relationships of the NSA9 peptide in inhibiting the proliferation of endothelial cells lines...

Sensing lymphoma cells based on a cell-penetrating/apoptosis-inducing/electron-transfer peptide probe

International Nuclear Information System (INIS)

Sugawara, Kazuharu; Shinohara, Hiroki; Kadoya, Toshihiko; Kuramitz, Hideki

2016-01-01

To electrochemically sense lymphoma cells (U937), we fabricated a multifunctional peptide probe that consists of cell-penetrating/apoptosis-inducing/electron-transfer peptides. Electron-transfer peptides derive from cysteine residue combined with the C-terminals of four tyrosine residues (Y_4). A peptide whereby Y_4C is bound to the C-terminals of protegrin 1 (RGGRLCYCRRRFCVCVGR-NH_2) is known to be an apoptosis-inducing agent against U937 cells, and is referred to as a peptide-1 probe. An oxidation response of the peptide-1 probe has been observed due to a phenolic hydroxyl group, and this response is decreased by the uptake of the peptide probe into the cells. To improve the cell membrane permeability against U937 cells, the RGGR at the N-terminals of the peptide-1 probe was replaced by RRRR (peptide-2 probe). In contrast, RNRCKGTDVQAWY_4C (peptide-3 probe), which recognizes ovalbumin, was constructed as a control. Compared with the other probes, the change in the peak current of the peptide-2 probe was the greatest at low concentrations and occurred in a short amount of time. Therefore, the cell membrane permeability of the peptide-2 probe was increased based on the arginine residues and the apoptosis-inducing peptides. The peak current was linear and ranged from 100 to 1000 cells/ml. The relative standard deviation of 600 cells/ml was 5.0% (n = 5). Furthermore, the membrane permeability of the peptide probes was confirmed using fluorescent dye. - Highlights: • We constructed a multifunctional peptide probe for the electrochemical sensing of lymphoma cells. • The peptide probe consists of cell-penetrating/apoptosis-inducing/electron-transfer peptides. • The electrode response of the peptide probe changes due to selective uptake into the cells.

Sensing lymphoma cells based on a cell-penetrating/apoptosis-inducing/electron-transfer peptide probe

Energy Technology Data Exchange (ETDEWEB)

Sugawara, Kazuharu, E-mail: kzsuga@maebashi-it.ac.jp [Maebashi Institute of Technology, Gunma 371-0816 (Japan); Shinohara, Hiroki; Kadoya, Toshihiko [Maebashi Institute of Technology, Gunma 371-0816 (Japan); Kuramitz, Hideki [Department of Environmental Biology and Chemistry, Graduate School of Science and Engineering for Research, University of Toyama, Toyama 930-8555 (Japan)

2016-06-14

To electrochemically sense lymphoma cells (U937), we fabricated a multifunctional peptide probe that consists of cell-penetrating/apoptosis-inducing/electron-transfer peptides. Electron-transfer peptides derive from cysteine residue combined with the C-terminals of four tyrosine residues (Y{sub 4}). A peptide whereby Y{sub 4}C is bound to the C-terminals of protegrin 1 (RGGRLCYCRRRFCVCVGR-NH{sub 2}) is known to be an apoptosis-inducing agent against U937 cells, and is referred to as a peptide-1 probe. An oxidation response of the peptide-1 probe has been observed due to a phenolic hydroxyl group, and this response is decreased by the uptake of the peptide probe into the cells. To improve the cell membrane permeability against U937 cells, the RGGR at the N-terminals of the peptide-1 probe was replaced by RRRR (peptide-2 probe). In contrast, RNRCKGTDVQAWY{sub 4}C (peptide-3 probe), which recognizes ovalbumin, was constructed as a control. Compared with the other probes, the change in the peak current of the peptide-2 probe was the greatest at low concentrations and occurred in a short amount of time. Therefore, the cell membrane permeability of the peptide-2 probe was increased based on the arginine residues and the apoptosis-inducing peptides. The peak current was linear and ranged from 100 to 1000 cells/ml. The relative standard deviation of 600 cells/ml was 5.0% (n = 5). Furthermore, the membrane permeability of the peptide probes was confirmed using fluorescent dye. - Highlights: • We constructed a multifunctional peptide probe for the electrochemical sensing of lymphoma cells. • The peptide probe consists of cell-penetrating/apoptosis-inducing/electron-transfer peptides. • The electrode response of the peptide probe changes due to selective uptake into the cells.

Role of Colored Cross-Correlation in Additive and Multiplicative White Noises on Upper Bound of Time Derivative of Information Entropy[PACS numbers: 02.50.Ey, 05.40.-a

Energy Technology Data Exchange (ETDEWEB)

Goswami, Gurupada; Majee, Pradip; Bag, Bidhan Chandra [Department of Chemistry, Visva-Bharati, Santiniketan 731 235 (India); Barik, Debashis [Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India)

2006-09-15

In this paper we have studied upper bound of time derivative of information entropy for colored cross-correlated noise driven open systems. The upper bound is calculated based on the Fokker-Planck equation and the Schwartz inequality principle. Our results consider the effect of the noise correlation strength and correlation time due to the correlation between additive and multiplicative white noises on the upper bound as well as relaxation time. The interplay of deterministic and random forces reveals extremal nature of the upper bound and its deviation from the time derivative of information entropy. (author)

Uniform Bounds for Black--Scholes Implied Volatility

OpenAIRE

Tehranchi, Michael Rummine

2016-01-01

In this note, Black--Scholes implied volatility is expressed in terms of various optimization problems. From these representations, upper and lower bounds are derived which hold uniformly across moneyness and call price. Various symmetries of the Black--Scholes formula are exploited to derive new bounds from old. These bounds are used to reprove asymptotic formulas for implied volatility at extreme strikes and/or maturities. the Society for Industrial and Applied Mathematics 10.1137/14095248X

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...

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

High cleavage efficiency of a 2A peptide derived from porcine teschovirus-1 in human cell lines, zebrafish and mice.

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Jin Hee Kim

Full Text Available When expression of more than one gene is required in cells, bicistronic or multicistronic expression vectors have been used. Among various strategies employed to construct bicistronic or multicistronic vectors, an internal ribosomal entry site (IRES has been widely used. Due to the large size and difference in expression levels between genes before and after IRES, however, a new strategy was required to replace IRES. A self-cleaving 2A peptide could be a good candidate to replace IRES because of its small size and high cleavage efficiency between genes upstream and downstream of the 2A peptide. Despite the advantages of the 2A peptides, its use is not widespread because (i there are no publicly available cloning vectors harboring a 2A peptide gene and (ii comprehensive comparison of cleavage efficiency among various 2A peptides reported to date has not been performed in different contexts. Here, we generated four expression plasmids each harboring different 2A peptides derived from the foot-and-mouth disease virus, equine rhinitis A virus, Thosea asigna virus and porcine teschovirus-1, respectively, and evaluated their cleavage efficiency in three commonly used human cell lines, zebrafish embryos and adult mice. Western blotting and confocal microscopic analyses revealed that among the four 2As, the one derived from porcine teschovirus-1 (P2A has the highest cleavage efficiency in all the contexts examined. We anticipate that the 2A-harboring cloning vectors we generated and the highest efficiency of the P2A peptide we demonstrated would help biomedical researchers easily adopt the 2A technology when bicistronic or multicistronic expression is required.

Statistical deconvolution of enthalpic energetic contributions to MHC-peptide binding affinity

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Drew Michael GB

2006-03-01

Full Text Available Abstract Background MHC Class I molecules present antigenic peptides to cytotoxic T cells, which forms an integral part of the adaptive immune response. Peptides are bound within a groove formed by the MHC heavy chain. Previous approaches to MHC Class I-peptide binding prediction have largely concentrated on the peptide anchor residues located at the P2 and C-terminus positions. Results A large dataset comprising MHC-peptide structural complexes was created by re-modelling pre-determined x-ray crystallographic structures. Static energetic analysis, following energy minimisation, was performed on the dataset in order to characterise interactions between bound peptides and the MHC Class I molecule, partitioning the interactions within the groove into van der Waals, electrostatic and total non-bonded energy contributions. Conclusion The QSAR techniques of Genetic Function Approximation (GFA and Genetic Partial Least Squares (G/PLS algorithms were used to identify key interactions between the two molecules by comparing the calculated energy values with experimentally-determined BL50 data. Although the peptide termini binding interactions help ensure the stability of the MHC Class I-peptide complex, the central region of the peptide is also important in defining the specificity of the interaction. As thermodynamic studies indicate that peptide association and dissociation may be driven entropically, it may be necessary to incorporate entropic contributions into future calculations.

Controlled Retention of BMP-2-Derived Peptide on Nanofibers Based on Mussel-Inspired Adhesion for Bone Formation.

Science.gov (United States)

Lee, Jinkyu; Perikamana, Sajeesh Kumar Madhurakkat; Ahmad, Taufiq; Lee, Min Suk; Yang, Hee Seok; Kim, Do-Gyoon; Kim, Kyobum; Kwon, Bosun; Shin, Heungsoo

2017-04-01

Although bone morphogenetic protein-2 (BMP-2) has been frequently used to stimulate bone formation, it has several side effects to be addressed, including the difficulty in optimization of clinically relevant doses and unwanted induction of cancerous signaling processes. In this study, an osteogenic peptide (OP) derived from BMP-2 was investigated as a substitute for BMP-2. In vitro studies showed that OP was able to enhance the osteogenic differentiation and mineralization of human mesenchymal stem cells (hMSCs). The peptides were then conjugated onto biocompatible poly-ι-lactide electrospun nanofibers through polydopamine chemistry. Surface chemical analysis proved that more than 80% of the peptides were stably retained on the nanofiber surface after 8 h of polydopamine coating during at least 28 days, and the amount of peptides that was retained increased depending on the polydopamine coating time. For instance, about 65% of the peptides were retained on nanofibers after 4 h of polydopamine coating. Also, a relatively small dose of peptides could effectively induce bone formation in in vivo critical-sized defects on the calvarial bones of mice. More than 50.4% ± 16.9% of newly formed bone was filled within the defect after treatment with only 10.5 ± 0.6 μg of peptides. Moreover, these groups had similar elastic moduli and contact hardnesses with host bone. Taken together, our results suggest that polydopamine-mediated OP immobilized on nanofibers can modulate the retention of relatively short lengths of peptides, which might make this an effective therapeutic remedy to guide bone regeneration using a relatively small amount of peptides.

Design and evaluation of antimalarial peptides derived from prediction of short linear motifs in proteins related to erythrocyte invasion.

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Alessandra Bianchin

Full Text Available The purpose of this study was to investigate the blood stage of the malaria causing parasite, Plasmodium falciparum, to predict potential protein interactions between the parasite merozoite and the host erythrocyte and design peptides that could interrupt these predicted interactions. We screened the P. falciparum and human proteomes for computationally predicted short linear motifs (SLiMs in cytoplasmic portions of transmembrane proteins that could play roles in the invasion of the erythrocyte by the merozoite, an essential step in malarial pathogenesis. We tested thirteen peptides predicted to contain SLiMs, twelve of them palmitoylated to enhance membrane targeting, and found three that blocked parasite growth in culture by inhibiting the initiation of new infections in erythrocytes. Scrambled peptides for two of the most promising peptides suggested that their activity may be reflective of amino acid properties, in particular, positive charge. However, one peptide showed effects which were stronger than those of scrambled peptides. This was derived from human red blood cell glycophorin-B. We concluded that proteome-wide computational screening of the intracellular regions of both host and pathogen adhesion proteins provides potential lead peptides for the development of anti-malarial compounds.

Chimeric opioid peptides: Tools for identifying opioid receptor types

International Nuclear Information System (INIS)

Xie, G.; Miyajima, A.; Yokota, T.; Arai, K.; Goldstein, A.

1990-01-01

The authors synthesized several chimeric [125J-labelled] peptides in which the N-terminal nine residues of dynorphin-32, a peptide selective for the κ opioid receptor, were replaced by opioid peptides selective for other opioid receptor types. Each chimeric peptide retained the high affinity and type selectivity characteristic of its N-terminal sequence. The common C-terminal two-thirds of the chimeric peptides served as an epitope recognized by the same monoclonal antibody. When bound to receptors on a cell surface or membrane preparation, these peptides could still bind specifically to the monoclonal antibody. These chimeric peptides should be useful for isolating μ, δ, and κ opioid receptors and for identifying opioid receptors on transfected cells in expression cloning procedures. The general approach using chimeric peptides should be applicable to other peptide receptors

Peptides derived from human galectin-3 N-terminal tail interact with its carbohydrate recognition domain in a phosphorylation-dependent manner

Energy Technology Data Exchange (ETDEWEB)

Berbís, M. Álvaro [Chemical and Physical Biology Department, Centro de Investigaciones Biológicas, CSIC, 28040 Madrid (Spain); André, Sabine [Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximilians University, 80539 Munich (Germany); Cañada, F. Javier [Chemical and Physical Biology Department, Centro de Investigaciones Biológicas, CSIC, 28040 Madrid (Spain); Pipkorn, Rüdiger [Central Peptide Synthesis Unit, German Cancer Research Center, 69120 Heidelberg (Germany); Ippel, Hans [Department of Biochemistry, CARIM, University of Maastricht, Maastricht (Netherlands); Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455 (United States); Mayo, Kevin H. [Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455 (United States); Kübler, Dieter [Biomolecular Interactions, German Cancer Research Center, 69120 Heidelberg (Germany); Gabius, Hans-Joachim [Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximilians University, 80539 Munich (Germany); Jiménez-Barbero, Jesús, E-mail: jjbarbero@cib.csic.es [Chemical and Physical Biology Department, Centro de Investigaciones Biológicas, CSIC, 28040 Madrid (Spain)

2014-01-03

Highlights: •Galectin-3 is composed of a carbohydrate recognition domain and an N-terminal tail. •Synthetic peptides derived from the tail are shown to interact with the CRD. •This interaction is modulated by Ser- and Tyr-phosphorylation of the peptides. -- Abstract: Galectin-3 (Gal-3) is a multi-functional effector protein that functions in the cytoplasm and the nucleus, as well as extracellularly following non-classical secretion. Structurally, Gal-3 is unique among galectins with its carbohydrate recognition domain (CRD) attached to a rather long N-terminal tail composed mostly of collagen-like repeats (nine in the human protein) and terminating in a short non-collagenous terminal peptide sequence unique in this lectin family and not yet fully explored. Although several Ser and Tyr sites within the N-terminal tail can be phosphorylated, the physiological significance of this post-translational modification remains unclear. Here, we used a series of synthetic (phospho)peptides derived from the tail to assess phosphorylation-mediated interactions with {sup 15}N-labeled Gal-3 CRD. HSQC-derived chemical shift perturbations revealed selective interactions at the backface of the CRD that were attenuated by phosphorylation of Tyr 107 and Tyr 118, while phosphorylation of Ser 6 and Ser 12 was essential. Controls with sequence scrambling underscored inherent specificity. Our studies shed light on how phosphorylation of the N-terminal tail may impact on Gal-3 function and prompt further studies using phosphorylated full-length protein.

Peptides derived from human galectin-3 N-terminal tail interact with its carbohydrate recognition domain in a phosphorylation-dependent manner

International Nuclear Information System (INIS)

Berbís, M. Álvaro; André, Sabine; Cañada, F. Javier; Pipkorn, Rüdiger; Ippel, Hans; Mayo, Kevin H.; Kübler, Dieter; Gabius, Hans-Joachim; Jiménez-Barbero, Jesús

2014-01-01

Highlights: •Galectin-3 is composed of a carbohydrate recognition domain and an N-terminal tail. •Synthetic peptides derived from the tail are shown to interact with the CRD. •This interaction is modulated by Ser- and Tyr-phosphorylation of the peptides. -- Abstract: Galectin-3 (Gal-3) is a multi-functional effector protein that functions in the cytoplasm and the nucleus, as well as extracellularly following non-classical secretion. Structurally, Gal-3 is unique among galectins with its carbohydrate recognition domain (CRD) attached to a rather long N-terminal tail composed mostly of collagen-like repeats (nine in the human protein) and terminating in a short non-collagenous terminal peptide sequence unique in this lectin family and not yet fully explored. Although several Ser and Tyr sites within the N-terminal tail can be phosphorylated, the physiological significance of this post-translational modification remains unclear. Here, we used a series of synthetic (phospho)peptides derived from the tail to assess phosphorylation-mediated interactions with 15 N-labeled Gal-3 CRD. HSQC-derived chemical shift perturbations revealed selective interactions at the backface of the CRD that were attenuated by phosphorylation of Tyr 107 and Tyr 118, while phosphorylation of Ser 6 and Ser 12 was essential. Controls with sequence scrambling underscored inherent specificity. Our studies shed light on how phosphorylation of the N-terminal tail may impact on Gal-3 function and prompt further studies using phosphorylated full-length protein

Novel haemoglobin-derived antimicrobial peptides from chicken (Gallus gallus) blood: purification, structural aspects and biological activity.

Science.gov (United States)

Vasilchenko, A S; Rogozhin, E A; Vasilchenko, A V; Kartashova, O L; Sycheva, M V

2016-12-01

To purify and characterize antimicrobial peptides derived from the acid extract of Gallus gallus blood cells. Two polypeptides (i.e. CHb-1 and CHb-2) with antibacterial activity were detected in the acidic extract of blood cells from chicken (G. gallus). The isolated peptides that possessed a potent antibacterial activity were purified using a two-step chromatography procedure that involved solid-phase extraction of a total protein/peptide extract followed by thin fractionation by reversed-phase high performance liquid chromatography (RP-HPLC). The molecular masses of the purified peptides were similar and were 4824·4 and 4825·2 Da, which have been measured by matrix-assisted laser desorption/ionization mass spectrometry (MALDI TOF MS). Their amino acid sequences were determined by Edman degradation and showed that the peptides were fully identical to the two fragments of G. gallus α-haemoglobin localized into different subunits (A and D respectively). The peptides were active in micromolar concentrations against Gram-negative Escherichia coli K12 TG1. Using the 1-N-phenylnaphthylamine, the FITC-dextran labelled probes and the live/dead staining allowed to show the hemocidin mode of action and estimate the pore size. In this study, for the first time, α-haemoglobin from chicken (G. gallus) has been investigated as a donor of the two high homologous native peptide fragments that possess potent antibacterial activity in vitro. These are membrane-active peptides and their mechanism of action against E. coli involves a toroidal pore formation. The obtained results expand the perception of the role of haemoglobin in a living system, describing it as a source of multifunction substances. Additionally, the data presented in this paper may contribute to the development of new, cost-effective, antimicrobial agents. © 2016 The Society for Applied Microbiology.

Peptide vaccination against multiple myeloma using peptides derived from anti-apoptotic protein

DEFF Research Database (Denmark)

Jørgensen, Nicolai Grønne Dahlager; Ahmad, Shamaila Munir; Abildgaard, N.

2016-01-01

The B-cell lymphoma-2 (Bcl-2) family of proteins play a crucial role in multiple myeloma (MM), contributing to lacking apoptosis which is a hallmark of the disease. This makes the Bcl-2 proteins interesting targets for therapeutic peptide vaccination. We report a phase I trial of therapeutic vacc...... vaccination. Vaccination against Bcl-2 was well tolerated and was able to induce immune responses in patients with relapsed MM. © Stem Cell Investigation. All rights reserved.......The B-cell lymphoma-2 (Bcl-2) family of proteins play a crucial role in multiple myeloma (MM), contributing to lacking apoptosis which is a hallmark of the disease. This makes the Bcl-2 proteins interesting targets for therapeutic peptide vaccination. We report a phase I trial of therapeutic...... vaccination with peptides from the proteins Bcl-2, Bcl-XL and Mcl-1 in patients with relapsed MM. Vaccines were given concomitant with bortezomib. Out of 7 enrolled patients, 4 received the full course of 8 vaccinations. The remaining 3 patients received fewer vaccinations due to progression, clinical...

Peptide-membrane Interactions by Spin-labeling EPR

Science.gov (United States)

Smirnova, Tatyana I.; Smirnov, Alex I.

2016-01-01

Site-directed spin labeling (SDSL) in combination with Electron Paramagnetic Resonance (EPR) spectroscopy is a well-established method that has recently grown in popularity as an experimental technique, with multiple applications in protein and peptide science. The growth is driven by development of labeling strategies, as well as by considerable technical advances in the field, that are paralleled by an increased availability of EPR instrumentation. While the method requires an introduction of a paramagnetic probe at a well-defined position in a peptide sequence, it has been shown to be minimally destructive to the peptide structure and energetics of the peptide-membrane interactions. In this chapter, we describe basic approaches for using SDSL EPR spectroscopy to study interactions between small peptides and biological membranes or membrane mimetic systems. We focus on experimental approaches to quantify peptide-membrane binding, topology of bound peptides, and characterize peptide aggregation. Sample preparation protocols including spin-labeling methods and preparation of membrane mimetic systems are also described. PMID:26477253

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

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.

Penilumamide, a novel lumazine peptide isolated from the marine-derived fungus, Penicillium sp. CNL-338†

OpenAIRE

Meyer, Sven W.; Mordhorst, Thorsten F.; Lee, Choonghwan; Jensen, Paul R.; Fenical, William; Köck, Matthias

2010-01-01

A novel lumazine peptide, penilumamide (1), was isolated from the fermentation broth of a marine-derived fungal strain, identified as Penicillium sp. (strain CNL-338) and the structure of the new metabolite was determined by analysis of ESI-TOF MS data combined with 1D and 2D NMR experiments.

Human C-peptide. Pt. 1

International Nuclear Information System (INIS)

Beischer, W.; Keller, L.; Maas, M.; Schiefer, E.; Pfeiffer, E.F.

1976-01-01

Synthetic human C-peptide bearing a tyrosine group at its amino end is labelled with 125 iodine using chloramin T or hydrogen peroxide and lactoperoxidase. The results of the two methods are compared. Antiserum to synthetic human C-peptide (without tyrosine), which was partially coupled to rabbit albumin, is raised in guinea pigs and goats. Goats show to be superior to guinea pips concerning antibody production. The so-called 'hook effect' phenomenon is observed when setting up the standard curves for the radioimmunoassay. Monotonically decreasing standard curves are obtained on dilution of antiserum with a high antibody titer which was produced by repeated immunization in goats. Free C-peptide and C-peptide bound to antiserum are separated using the anion exchange resin amberlite. Using this separation technique we excluded unspecific binding of labelled C-peptide to protein fractions in serum of diabetics. The sensitivity of our radioimmunoassay is approx. 0.3 ng C-peptide/ml serum. Intra- and interassay variability are below 10%. Human proinsulin is the only substance found to crossreact with the antiserum. (orig.) [de

Purification of Angiotensin Converting Enzyme Inhibitory Peptide Derived From Kacang Goat Meat Protein Hydrolysate

OpenAIRE

Jamhari, J; Yusiati, L.M; Suryanto, E; Cahyanto, M.N; Erwanto, Y; Muguruma, M

2013-01-01

The objective of this study was to identify the Angiotensin Converting Enzyme (ACE) inhibitorypeptide derived from Kacang goat meat protein hydrolysate. Kacang goat meat loin section washydrolyzed with pepsin, trypsin and chymotrypsin. Protein hydrolysate of Kacang goat meat was thentested the protein concentration and ACE inhibitory activity. ACE inhibitory peptide of the proteinhydrolysate was purified through several steps of purification by column SEP-PAK Plus C18 Cartridgeand RP-HPLC usi...

Entropy Bounds for Constrained Two-Dimensional Fields

DEFF Research Database (Denmark)

Forchhammer, Søren Otto; Justesen, Jørn

1999-01-01

The maximum entropy and thereby the capacity of 2-D fields given by certain constraints on configurations are considered. Upper and lower bounds are derived.......The maximum entropy and thereby the capacity of 2-D fields given by certain constraints on configurations are considered. Upper and lower bounds are derived....

Proposal for novel curcumin derivatives as potent inhibitors against Alzheimer's disease: Ab initio molecular simulations on the specific interactions between amyloid-beta peptide and curcumin

Science.gov (United States)

Ota, Shintaro; Fujimori, Mitsuki; Ishimura, Hiromi; Shulga, Sergiy; Kurita, Noriyuki

2017-10-01

Accumulation of amyloid-β (Aβ) peptides in a brain is closely related with the pathogenesis of Alzheimer's disease. To suppress the production of Aβ peptides, we propose novel curcumin derivatives and investigate their binding properties with the amyloid precursor protein (APP), using protein-ligand docking as well as ab initio molecular simulations. Our proposed derivative (curcumin XIV) is found to have a large binding energy with APP and interacts strongly with the cleavage site Ala19 by secretase. It is thus expected that curcumin XIV can protect APP from the secretase attack and be a potent inhibitor against the production of Aβ peptides.

Labeling schemes for bounded degree graphs

DEFF Research Database (Denmark)

Adjiashvili, David; Rotbart, Noy Galil

2014-01-01

We investigate adjacency labeling schemes for graphs of bounded degree Δ = O(1). In particular, we present an optimal (up to an additive constant) log n + O(1) adjacency labeling scheme for bounded degree trees. The latter scheme is derived from a labeling scheme for bounded degree outerplanar...... graphs. Our results complement a similar bound recently obtained for bounded depth trees [Fraigniaud and Korman, SODA 2010], and may provide new insights for closing the long standing gap for adjacency in trees [Alstrup and Rauhe, FOCS 2002]. We also provide improved labeling schemes for bounded degree...

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

Absolute Lower Bound on the Bounce Action

Science.gov (United States)

Sato, Ryosuke; Takimoto, Masahiro

2018-03-01

The decay rate of a false vacuum is determined by the minimal action solution of the tunneling field: bounce. In this Letter, we focus on models with scalar fields which have a canonical kinetic term in N (>2 ) dimensional Euclidean space, and derive an absolute lower bound on the bounce action. In the case of four-dimensional space, we show the bounce action is generically larger than 24 /λcr, where λcr≡max [-4 V (ϕ )/|ϕ |4] with the false vacuum being at ϕ =0 and V (0 )=0 . We derive this bound on the bounce action without solving the equation of motion explicitly. Our bound is derived by a quite simple discussion, and it provides useful information even if it is difficult to obtain the explicit form of the bounce solution. Our bound offers a sufficient condition for the stability of a false vacuum, and it is useful as a quick check on the vacuum stability for given models. Our bound can be applied to a broad class of scalar potential with any number of scalar fields. We also discuss a necessary condition for the bounce action taking a value close to this lower bound.

Soluble N-Ethylmaleimide-Sensitive Factor Attachment Protein Receptor-Derived Peptides for Regulation of Mast Cell Degranulation.

Science.gov (United States)

Yang, Yoosoo; Kong, Byoungjae; Jung, Younghoon; Park, Joon-Bum; Oh, Jung-Mi; Hwang, Jaesung; Cho, Jae Youl; Kweon, Dae-Hyuk

2018-01-01

Vesicle-associated V-soluble N -ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins and target membrane-associated T-SNAREs (syntaxin 4 and SNAP-23) assemble into a core trans -SNARE complex that mediates membrane fusion during mast cell degranulation. This complex plays pivotal roles at various stages of exocytosis from the initial priming step to fusion pore opening and expansion, finally resulting in the release of the vesicle contents. In this study, peptides with the sequences of various SNARE motifs were investigated for their potential inhibitory effects against SNARE complex formation and mast cell degranulation. The peptides with the sequences of the N-terminal regions of vesicle-associated membrane protein 2 (VAMP2) and VAMP8 were found to reduce mast cell degranulation by inhibiting SNARE complex formation. The fusion of protein transduction domains to the N-terminal of each peptide enabled the internalization of the fusion peptides into the cells equally as efficiently as cell permeabilization by streptolysin-O without any loss of their inhibitory activities. Distinct subsets of mast cell granules could be selectively regulated by the N-terminal-mimicking peptides derived from VAMP2 and VAMP8, and they effectively decreased the symptoms of atopic dermatitis in mouse models. These results suggest that the cell membrane fusion machinery may represent a therapeutic target for atopic dermatitis.

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.

Penilumamide, a novel lumazine peptide isolated from the marine-derived fungus, Penicillium sp. CNL-338†

Science.gov (United States)

Meyer, Sven W.; Mordhorst, Thorsten F.; Lee, Choonghwan; Jensen, Paul R.; Fenical, William; Köck, Matthias

2013-01-01

A novel lumazine peptide, penilumamide (1), was isolated from the fermentation broth of a marine-derived fungal strain, identified as Penicillium sp. (strain CNL-338) and the structure of the new metabolite was determined by analysis of ESI-TOF MS data combined with 1D and 2D NMR experiments. PMID:20401392

Synthesis of peptide thioacids at neutral pH using bis(2-sulfanylethyl)amido peptide precursors.

Science.gov (United States)

Pira, Silvain L; Boll, Emmanuelle; Melnyk, Oleg

2013-10-18

Reaction of bis(2-sulfanylethyl)amido (SEA) peptides with triisopropylsilylthiol in water at neutral pH yields peptide thiocarboxylates. An alkylthioester derived from β-alanine was used to trap the released bis(2-sulfanylethyl)amine and displace the equilibrium toward the peptide thiocarboxylate.

Search for quasi bound η mesons

International Nuclear Information System (INIS)

Machner, H

2015-01-01

The search for a quasi bound η meson in atomic nuclei is reviewed. This tentative state is studied theoretically as well as experimentally. The theory starts from elastic η nucleon scattering which is derived from production data within some models. From this interaction the η nucleus interaction is derived. Model calculations predict binding energies and widths of the quasi bound state. Another method is to derive the η nucleus interaction from excitation functions of η production experiments. The s wave interaction is extracted from such data via final state interaction (FSI) theorem. We give the derivation of s wave amplitudes in partial wave expansion and in helicity amplitudes and their relation to observables. Different experiments extracting the FSI are discussed as are production experiments. So far only three experiments give evidence for the existence of the quasi bound state: a pion double charge exchange experiment, an effective mass measurement, and a transfer reaction at recoil free kinematics with observation of the decay of the state. (topical review)

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

B7H6-derived peptides trigger TNF-α-dependent immunostimulatory activity of lymphocytic NK92-MI cells.

Science.gov (United States)

Phillips, Mariana; Romeo, Francesca; Bitsaktsis, Constantine; Sabatino, David

2016-09-01

The rise of biologics that can stimulate immune responses towards the eradication of tumors has led to the evolution of cancer-based immunotherapy. Representatively, B7H6 has been recently identified as a protein ligand on tumor cells that binds specifically to the NKp30 receptor and triggers NK cell-derived cytokine production, which ultimately leads to tumor cell lysis and death. In an effort to develop effective immunotherapy approaches, the rational design of a novel class of immunostimulatory peptides (IPs) derived from the binding interface of B7H6:NKp30 is described in this study. The IPs comprised the B7H6 active site sequence for NKp30 binding and immunostimulatory activity. An aminohexanoic acid linker was also introduced at the N-terminus of the peptides for FITC-labeling by Fmoc-solid phase peptide synthesis. The peptides were characterized by LCMS to confirm identities and purities >95%. The secondary structures of the peptides were examined by CD spectroscopy in H2 O, PBS and a H2 O:TFE mixture which demonstrated versatile peptide structures which transitioned from random coil (H2 O) to α-helical (PBS) and turn-type (H2 O:TFE) conformations. Their biological properties were then evaluated by flow cytometry, enzyme-linked immunosorbent assays (ELISAs), and cell death assays. The occupancy of the synthetic peptides to a human NK cell line demonstrated comparable binding relative to the natural NKp30 ligand, B7H6, and the human anti-NKp30 monoclonal antibody (mAb), in a concentration dependent manner. A competitive binding assay between the human anti-NKp30 mAb or B7H6, and the synthetic peptides, demonstrated partial displacement of the ligands upon anti-NKp30 mAb treatment, suggesting NKp30 receptor specificities by the synthetic peptides. Moreover, the immunostimulatory activity of B7H6 was demonstrated by the secretion of the pro-inflammatory cytokines tumor necrosis factor-alfa (TNF-α) and interferon gamma (IFN-γ) by the human NK cell line. The

Entire Functions of Bounded L-Index: Its Zeros and Behavior of Partial Logarithmic Derivatives

Directory of Open Access Journals (Sweden)

Andriy Bandura

2017-01-01

Full Text Available In this paper, we obtain new sufficient conditions of boundedness of L-index in joint variables for entire function in Cn functions. They give an estimate of maximum modulus of an entire function by its minimum modulus on a skeleton in a polydisc and describe the behavior of all partial logarithmic derivatives and the distribution of zeros. In some sense, the obtained results are new for entire functions of bounded index and l-index in C too. They generalize known results of Fricke, Sheremeta, and Kuzyk.

Mesobuthus Venom-Derived Antimicrobial Peptides Possess Intrinsic Multifunctionality and Differential Potential as Drugs

Directory of Open Access Journals (Sweden)

Bin Gao

2018-02-01

Full Text Available Animal venoms are a mixture of peptides and proteins that serve two basic biological functions: predation and defense against both predators and microbes. Antimicrobial peptides (AMPs are a common component extensively present in various scorpion venoms (herein abbreviated as svAMPs. However, their roles in predation and defense against predators and potential as drugs are poorly understood. Here, we report five new venom peptides with antimicrobial activity from two Mesobuthus scorpion species. These α-helical linear peptides displayed highly bactericidal activity toward all the Gram-positive bacteria used here but differential activity against Gram-negative bacteria and fungi. In addition to the antibiotic activity, these AMPs displayed lethality to houseflies and hemotoxin-like toxicity on mice by causing hemolysis, tissue damage and inducing inflammatory pain. Unlike AMPs from other origins, these venom-derived AMPs seem to be unsuitable as anti-infective drugs due to their high hemolysis and low serum stability. However, MeuTXKβ1, a known two-domain Mesobuthus AMP, is an exception since it exhibits high activity toward antibiotic resistant Staphylococci clinical isolates with low hemolysis and high serum stability. The findings that the classical AMPs play predatory and defensive roles indicate that the multifunctionality of scorpion venom components is an intrinsic feature likely evolved by natural selection from microbes, prey and predators of scorpions. This definitely provides an excellent system in which one can study how a protein adaptively evolves novel functions in a new environment. Meantimes, new strategies are needed to remove the toxicity of svAMPs on eukaryotic cells when they are used as leads for anti-infective drugs.

Effect of time delay on the upper bound of the time derivative of information entropy in a stochastic dynamical system

International Nuclear Information System (INIS)

Zhang Min-Min; Mei Dong-Cheng; Wang Can-Jun

2011-01-01

The effects of the time delay on the upper bound of the time derivative of information entropy are investigated in a time-delayed dynamical system driven by correlated noise. Using the Markov approximation of the stochastic delay differential equations and the Schwartz inequality principle, we obtain an analytical expression for the upper bound U B (t) of the time derivative of the information entropy. The results show that there is a critical value of τ (delay time), and U B (t) presents opposite behaviours on difference sides of the critical value. For the case of the weak additive noise, τ can induce a reentrance transition. Delay time τ also causes a reversal behaviour in U B (t)-λ plot, where λ denotes the degree of the correlation between the two noises. (general)

Elastin-derived peptides are new regulators of insulin resistance development in mice

DEFF Research Database (Denmark)

Blaise, Sébastien; Romier, Béatrice; Kawecki, Charlotte

2013-01-01

. In the current study, we show that elastin-derived peptides (EDPs) may be involved in the development of insulin resistance (IRES) in mice. In chow-fed mice, acute or chronic intravenous injections of EDPs induced hyperglycemic effects associated with glucose uptake reduction and IRES in skeletal muscle, liver......, and adipose tissue. Based on in vivo, in vitro, and in silico approaches, we propose that this IRES is due to interaction between the insulin receptor (IR) and the neuraminidase-1 subunit of the elastin receptor complex triggered by EDPs. This interplay was correlated with decreased sialic acid levels...

Peptide p5 binds both heparinase-sensitive glycosaminoglycans and fibrils in patient-derived AL amyloid extracts

Energy Technology Data Exchange (ETDEWEB)

Martin, Emily B.; Williams, Angela [Department of Medicine, University of Tennessee Graduate School of Medicine, 1924 Alcoa Highway, Knoxville, TN 37922 (United States); Heidel, Eric [Department of Surgery, University of Tennessee Graduate School of Medicine, 1924 Alcoa Highway, Knoxville, TN 37922 (United States); Macy, Sallie [Department of Medicine, University of Tennessee Graduate School of Medicine, 1924 Alcoa Highway, Knoxville, TN 37922 (United States); Kennel, Stephen J. [Department of Medicine, University of Tennessee Graduate School of Medicine, 1924 Alcoa Highway, Knoxville, TN 37922 (United States); Department of Radiology, University of Tennessee Graduate School of Medicine, 1924 Alcoa Highway, Knoxville, TN 37922 (United States); Wall, Jonathan S., E-mail: jwall@utmck.edu [Department of Medicine, University of Tennessee Graduate School of Medicine, 1924 Alcoa Highway, Knoxville, TN 37922 (United States); Department of Radiology, University of Tennessee Graduate School of Medicine, 1924 Alcoa Highway, Knoxville, TN 37922 (United States)

2013-06-21

Highlights: •Polybasic peptide p5 binds human light chain amyloid extracts. •The binding of p5 with amyloid involves both glycosaminoglycans and fibrils. •Heparinase treatment led to a correlation between p5 binding and fibril content. •p5 binding to AL amyloid requires electrostatic interactions. -- Abstract: In previously published work, we have described heparin-binding synthetic peptides that preferentially recognize amyloid deposits in a mouse model of reactive systemic (AA) amyloidosis and can be imaged by using positron and single photon emission tomographic imaging. We wanted to extend these findings to the most common form of visceral amyloidosis, namely light chain (AL); however, there are no robust experimental animal models of AL amyloidosis. To further define the binding of the lead peptide, p5, to AL amyloid, we characterized the reactivity in vitro of p5 with in situ and patient-derived AL amyloid extracts which contain both hypersulfated heparan sulfate proteoglycans as well as amyloid fibrils. Histochemical staining demonstrated that the peptide specifically localized with tissue-associated AL amyloid deposits. Although we anticipated that p5 would undergo electrostatic interactions with the amyloid-associated glycosaminoglycans expressing heparin-like side chains, no significant correlation between peptide binding and glycosaminoglycan content within amyloid extracts was observed. In contrast, following heparinase I treatment, although overall binding was reduced, a positive correlation between peptide binding and amyloid fibril content became evident. This interaction was further confirmed using synthetic light chain fibrils that contain no carbohydrates. These data suggest that p5 can bind to both the sulfated glycosaminoglycans and protein fibril components of AL amyloid. Understanding these complex electrostatic interactions will aid in the optimization of synthetic peptides for use as amyloid imaging agents and potentially as

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.

Role of αA-crystallin-derived αA66-80 peptide in guinea pig lens crystallin aggregation and insolubilization.

Science.gov (United States)

Raju, Murugesan; Mooney, Brian P; Thakkar, Kavi M; Giblin, Frank J; Schey, Kevin L; Sharma, K Krishna

2015-03-01

Earlier we reported that low molecular weight (LMW) peptides accumulate in aging human lens tissue and that among the LMW peptides, the chaperone inhibitor peptide αA66-80, derived from α-crystallin protein, is one of the predominant peptides. We showed that in vitro αA66-80 induces protein aggregation. The current study was undertaken to determine whether LMW peptides are also present in guinea pig lens tissue subjected to hyperbaric oxygen (HBO) in vivo. The nuclear opacity induced by HBO in guinea pig lens is the closest animal model for studying age-related cataract formation in humans. A LMW peptide profile by mass spectrometry showed the presence of an increased amount of LMW peptides in HBO-treated guinea pig lenses compared to age-matched controls. Interestingly, the mass spectrometric data also showed that the chaperone inhibitor peptide αA66-80 accumulates in HBO-treated guinea pig lens. Following incubation of synthetic chaperone inhibitor peptide αA66-80 with α-crystallin from guinea pig lens extracts, we observed a decreased ability of α-crystallin to inhibit the amorphous aggregation of the target protein alcohol dehydrogenase and the formation of large light scattering aggregates, similar to those we have observed with human α-crystallin and αA66-80 peptide. Further, time-lapse recordings showed that a preformed complex of α-crystallin and αA66-80 attracted additional crystallin molecules to form even larger aggregates. These results demonstrate that LMW peptide-mediated cataract development in aged human lens and in HBO-induced lens opacity in the guinea pig may have common molecular pathways. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

Inequalities and bounds for nucleon-nucleon scattering

International Nuclear Information System (INIS)

Ramandurai, K.S.

1979-08-01

The objective of this work is to derive model-independent inequalities and bounds for nucleon-nucleon elastic scattering amplitudes based on well-established theoretical principles and symmetries. Two classes of methods are used: algebraic and variational. In the algebraic part, the author derives inequalities and bounds for NN amplitudes and observables using their mutual relations and x symmetries. In the variational part, he employs Lagrange's method of undetermined multipliers to evaluate the bounds. He tests the predictions of a sample of proposed phase shifts at three different energies using the results obtained

The antibacterial activity of peptides derived from human beta-2 glycoprotein I is inhibited by protein H and M1 protein from Streptococcus pyogenes

NARCIS (Netherlands)

Nilsson, Maria; Wasylik, Sylwia; Mörgelin, Matthias; Olin, Anders I.; Meijers, Joost C. M.; Derksen, Ronald H. W. M.; de Groot, Philip G.; Herwald, Heiko

2008-01-01

During the last years, the importance of antibacterial peptides has attracted considerable attention. We report here that peptides derived from the fifth domain of beta-2 glycoprotein I (beta(2)GPI), a human heparin binding plasma protein, have antibacterial activities against Gram-positive and

Zein nanoparticle as a novel BMP6 derived peptide carrier for enhanced osteogenic differentiation of C2C12 cells.

Science.gov (United States)

Hadavi, Mahvash; Hasannia, Sadegh; Faghihi, Shahab; Mashayekhi, Farhad; Homazadeh, Homayoun; Mostofi, Seyed Behrooz

2018-01-26

Zein nanoparticles as a carrier system for BMP6-derived peptide were prepared by liquid-liquid phase separation procedure and characterized with SEM, DLS, FTIR and thermogravimetric methods. After peptide encapsulation, nanoparticle size increased from 236.3 ± 92.2 nm to 379.4 ± 116.8 nm. The encapsulation efficiency of peptide was 72.6% and the release of peptide from Zein nanoparticles was partly sustained in trypsin containing phosphate buffered saline (pH 7.4) for up to 14 days. Peptide-loaded nanoparticles showed similar cell viability compared with blank ones. ALP activity of C2C12 cells treated with peptide-loaded nanoparticles (500 µg/mL) was evaluated 7, 14, 21 and 28 days after culture. In peptide-loaded nanoparticles, ALP activity was significantly higher (p < .05) compared with other groups at day 14. Alizarin Red S staining showed, C2C12 cells behind peptide-loaded nanoparticles had significantly (p < .05) higher calcium deposition at day 21. The results of RT-qPCR show that the BMP-6 peptide activated expression of RUNX2 as a transcription factor. In turn, RUNX2 regulates SPP1 and BGLAP gene expression, as osteogenic marker genes. The results confirm that the peptide-loaded Zein nanoparticles, as osteoinductive material, may be used to repair small area of bone defects, with low load bearing.

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 ...

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...

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.

Antibacterial Synthetic Peptides Derived from Bovine Lactoferricin Exhibit Cytotoxic Effect against MDA-MB-468 and MDA-MB-231 Breast Cancer Cell Lines

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Yerly Vargas Casanova

2017-09-01

Full Text Available Linear, dimeric, tetrameric, and cyclic peptides derived from lactoferricin B, containing the RRWQWR motif, were designed, synthesized, purified, and characterized using RP-HPLC chromatography and MALDI-TOF mass spectrometry. The antibacterial activity of the designed peptides against E. coli (ATCC 11775 and 25922 and their cytotoxic effect against MDA-MB-468 and MDA-MB-231 breast cancer cell lines were evaluated. Dimeric and tetrameric peptides showed higher antibacterial activity in both bacteria strains than linear peptides. The dimeric peptide (RRWQWR2K-Ahx exhibited the highest antibacterial activity against the tested bacterial strains. Furthermore, the peptides with high antibacterial activity exhibited significant cytotoxic effect against the tested breast cancer cell lines. This cytotoxic effect was fast and dependent on the peptide concentration. The tetrameric molecule containing RRWQWR motif has an optimal cytotoxic effect at a concentration of 22 µM. The evaluated dimeric and tetrameric peptides could be considered as candidates for developing new therapeutic agents against breast cancer. Polyvalence of linear sequences could be considered as a novel and versatile strategy for obtaining molecules with high anticancer activity.

Antibacterial Synthetic Peptides Derived from Bovine Lactoferricin Exhibit Cytotoxic Effect against MDA-MB-468 and MDA-MB-231 Breast Cancer Cell Lines.

Science.gov (United States)

Vargas Casanova, Yerly; Rodríguez Guerra, Jorge Antonio; Umaña Pérez, Yadi Adriana; Leal Castro, Aura Lucía; Almanzar Reina, Giovanni; García Castañeda, Javier Eduardo; Rivera Monroy, Zuly Jenny

2017-09-29

Linear, dimeric, tetrameric, and cyclic peptides derived from lactoferricin B, containing the RRWQWR motif, were designed, synthesized, purified, and characterized using RP-HPLC chromatography and MALDI-TOF mass spectrometry. The antibacterial activity of the designed peptides against E. coli (ATCC 11775 and 25922) and their cytotoxic effect against MDA-MB-468 and MDA-MB-231 breast cancer cell lines were evaluated. Dimeric and tetrameric peptides showed higher antibacterial activity in both bacteria strains than linear peptides. The dimeric peptide (RRWQWR)₂K-Ahx exhibited the highest antibacterial activity against the tested bacterial strains. Furthermore, the peptides with high antibacterial activity exhibited significant cytotoxic effect against the tested breast cancer cell lines. This cytotoxic effect was fast and dependent on the peptide concentration. The tetrameric molecule containing RRWQWR motif has an optimal cytotoxic effect at a concentration of 22 µM. The evaluated dimeric and tetrameric peptides could be considered as candidates for developing new therapeutic agents against breast cancer. Polyvalence of linear sequences could be considered as a novel and versatile strategy for obtaining molecules with high anticancer activity.

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.

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.

Morphofunctional reaction of bacteria treated with antimicrobial peptides derived from farm animal platelets.

Science.gov (United States)

Vasilchenko, Alexey S; Dymova, Veronica V; Kartashova, Olga L; Sycheva, Maria V

2015-03-01

Classical microbiological approach and atomic force microscopy were used to evaluate the mechanisms of biological activity of antimicrobial peptides (AMPs) derived from platelets of farm animals. It is established that AMPs inhibit both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) microorganisms. Differences revealed in the biological activity of AMP preparations obtained from the organisms of various species can be reduced to quantitative differences. While qualitative changes of bacterial cells were substantially similar, changes in the integrity of cell walls resulted in disintegration of the bacterial outer and/or cytoplasmic membranes.

Peptides, polypeptides and peptide-polymer hybrids as nucleic acid carriers.

Science.gov (United States)

Ahmed, Marya

2017-10-24

Cell penetrating peptides (CPPs), and protein transduction domains (PTDs) of viruses and other natural proteins serve as a template for the development of efficient peptide based gene delivery vectors. PTDs are sequences of acidic or basic amphipathic amino acids, with superior membrane trespassing efficacies. Gene delivery vectors derived from these natural, cationic and cationic amphipathic peptides, however, offer little flexibility in tailoring the physicochemical properties of single chain peptide based systems. Owing to significant advances in the field of peptide chemistry, synthetic mimics of natural peptides are often prepared and have been evaluated for their gene expression, as a function of amino acid functionalities, architecture and net cationic content of peptide chains. Moreover, chimeric single polypeptide chains are prepared by a combination of multiple small natural or synthetic peptides, which imparts distinct physiological properties to peptide based gene delivery therapeutics. In order to obtain multivalency and improve the gene delivery efficacies of low molecular weight cationic peptides, bioactive peptides are often incorporated into a polymeric architecture to obtain novel 'polymer-peptide hybrids' with improved gene delivery efficacies. Peptide modified polymers prepared by physical or chemical modifications exhibit enhanced endosomal escape, stimuli responsive degradation and targeting efficacies, as a function of physicochemical and biological activities of peptides attached onto a polymeric scaffold. The focus of this review is to provide comprehensive and step-wise progress in major natural and synthetic peptides, chimeric polypeptides, and peptide-polymer hybrids for nucleic acid delivery applications.

Molecular dynamics simulations of peptide adsorption on self-assembled monolayers

International Nuclear Information System (INIS)

Xie Yun; Liu Meifeng; Zhou Jian

2012-01-01

All-atom molecular dynamics simulations are performed to investigate the neuromedin-B peptide adsorption on the self-assembled monolayers (SAMs) of SH(CH 2 ) 10 N + (CH 3 ) 2 CH 2 CH(OH)CH 2 SO 3 - (SBT), SH(CH 2 ) 10 OH and SH(CH 2 ) 10 CH 3 . The force-distance profiles show that the surface resistance to peptide adsorption is mainly generated by the water molecules tightly bound to surfaces via hydrogen bonds (hydration water molecules); but surfaces themselves may also set an energy barrier for the approaching peptide. For the SBT-SAM, the surface first exerts a relatively high repulsive force and then a rather week attractive force on the approaching peptide; meanwhile the hydration water molecules exert a strong repulsive force on the peptide. Therefore, SBT-SAM has an excellent performance on resisting protein adsorption. For the OH-SAM and CH 3 -SAM, surfaces show low or little energy barrier but strong affinity to the peptide; and the hydration water molecules apply merely a repulsive force within a much narrower range and with lower intensity compared with the case for the SBT-SAM. The analysis of structural and dynamical properties of the peptide, surface and water indicates that possible factors contributing to surface resistance include the hydrogen-bond formation capability of surfaces, mobility of water molecules near surfaces, surface packing density and chain flexibility of SAMs. There are a large number of hydrogen bonds formed between the hydration water molecules and the functional groups of the SBT-SAM, which greatly lowers the mobility of water molecules near the surface. This tightly-bound water layer effectively reduces the direct contact between the surface and the peptide. Furthermore, the SBT-SAM also has a high flexibility and a low surface packing density, which allows water molecules to penetrate into the surface to form tightly-bound networks and therefore reduces the affinity between the peptide and the surface. The results show that

A PEDF-Derived Peptide Inhibits Retinal Neovascularization and Blocks Mobilization of Bone Marrow-Derived Endothelial Progenitor Cells

Directory of Open Access Journals (Sweden)

Richard Longeras

2012-01-01

Full Text Available Proliferative diabetic retinopathy is characterized by pathological retinal neovascularization, mediated by both angiogenesis (involving mature endothelial cells and vasculogenesis (involving bone marrow-derived circulating endothelial progenitor cells (EPCs. Pigment epithelium-derived factor (PEDF contains an N-terminal 34-amino acid peptide (PEDF-34 that has antiangiogenic properties. Herein, we present a novel finding that PEDF-34 also possesses antivasculogenic activity. In the oxygen-induced retinopathy (OIR model using transgenic mice that have Tie2 promoter-driven GFP expression, we quantified Tie2GFP+ cells in bone marrow and peripheral blood by fluorescence-activated cell sorting (FACS. OIR significantly increased the number of circulating Tie2-GFP+ at P16, correlating with the peak progression of neovascularization. Daily intraperitoneal injections of PEDF-34 into OIR mice decreased the number of Tie2-GFP+ cells in the circulation at P16 by 65% but did not affect the number of Tie2-GFP+ cells in the bone marrow. These studies suggest that PEDF-34 attenuates EPC mobilization from the bone marrow into the blood circulation during retinal neovascularization.

Human C-peptide. Pt. 1. Radioimmunoassay

Energy Technology Data Exchange (ETDEWEB)

Beischer, W; Keller, L; Maas, M; Schiefer, E; Pfeiffer, E F [Ulm Univ. (Germany, F.R.). Abt. Innere Medizin, Endokrinologie und Stoffwechsel

1976-08-01

Synthetic human C-peptide bearing a tyrosine group at its amino end is labelled with /sup 125/iodine using chloramin T or hydrogen peroxide and lactoperoxidase. The results of the two methods are compared. Antiserum to synthetic human C-peptide (without tyrosine), which was partially coupled to rabbit albumin, is raised in guinea pigs and goats. Goats show to be superior to guinea pips concerning antibody production. The so-called 'hook effect' phenomenon is observed when setting up the standard curves for the radioimmunoassay. Monotonically decreasing standard curves are obtained on dilution of antiserum with a high antibody titer which was produced by repeated immunization in goats. Free C-peptide and C-peptide bound to antiserum are separated using the anion exchange resin amberlite. Using this separation technique we excluded unspecific binding of labelled C-peptide to protein fractions in serum of diabetics. The sensitivity of our radioimmunoassay is approx. 0.3 ng C-peptide/ml serum. Intra- and interassay variability are below 10%. Human proinsulin is the only substance found to crossreact with the antiserum.

Deglycosylation of chondroitin sulfate proteoglycan and derived peptides

International Nuclear Information System (INIS)

Campbell, S.C.; Krueger, R.C.; Schwartz, N.B.

1990-01-01

In order to define the domain structure of proteoglycans as well as identify primary amino acid sequences specific for attachment of the various carbohydrate substituents, reliable techniques for deglycosylating proteoglycans are required. In this study, deglycosylation of cartilage chondroitin sulfate proteoglycan (CSPG) with minimal core protein cleavage was accomplished by digestion with chondroitinase ABC and keratanase, followed by treatment with anhydrous HF in pyridine. Nearly complete deglycosylation of secreted proteoglycan was verified within 45 min of HF treatment by loss of incorporated [ 3 H]glucosamine label from the proteoglycan as a function of time of treatment, as well as by direct analysis of carbohydrate content and xylosyltransferase acceptor activity of unlabeled core protein preparations. The deglycosylated CSPG preparations were homogeneous and of high molecular weight. Comparison of the intact deglycosylated core protein preparations with newly synthesized unprocessed precursors suggested that extensive proteolytic cleavage of the core protein did not occur during normal intracellular processing. Furthermore, peptide patterns generated after clostripain digestion of core protein precursor and of deglycosylated secreted proteoglycan were comparable. With the use of the clostripain digestion procedure, peptides were produced from unlabeled proteoglycan, and two predominant peptides from the most highly glycosylated regions were isolated, characterized, and deglycosylated. These peptides were found to follow similar kinetics of deglycosylation and to acquire xylose activity comparable to the intact core protein

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.

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

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

Multi-species sequence comparison reveals conservation of ghrelin gene-derived splice variants encoding a truncated ghrelin peptide.

Science.gov (United States)

Seim, Inge; Jeffery, Penny L; Thomas, Patrick B; Walpole, Carina M; Maugham, Michelle; Fung, Jenny N T; Yap, Pei-Yi; O'Keeffe, Angela J; Lai, John; Whiteside, Eliza J; Herington, Adrian C; Chopin, Lisa K

2016-06-01

The peptide hormone ghrelin is a potent orexigen produced predominantly in the stomach. It has a number of other biological actions, including roles in appetite stimulation, energy balance, the stimulation of growth hormone release and the regulation of cell proliferation. Recently, several ghrelin gene splice variants have been described. Here, we attempted to identify conserved alternative splicing of the ghrelin gene by cross-species sequence comparisons. We identified a novel human exon 2-deleted variant and provide preliminary evidence that this splice variant and in1-ghrelin encode a C-terminally truncated form of the ghrelin peptide, termed minighrelin. These variants are expressed in humans and mice, demonstrating conservation of alternative splicing spanning 90 million years. Minighrelin appears to have similar actions to full-length ghrelin, as treatment with exogenous minighrelin peptide stimulates appetite and feeding in mice. Forced expression of the exon 2-deleted preproghrelin variant mirrors the effect of the canonical preproghrelin, stimulating cell proliferation and migration in the PC3 prostate cancer cell line. This is the first study to characterise an exon 2-deleted preproghrelin variant and to demonstrate sequence conservation of ghrelin gene-derived splice variants that encode a truncated ghrelin peptide. This adds further impetus for studies into the alternative splicing of the ghrelin gene and the function of novel ghrelin peptides in vertebrates.

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....

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

Directory of Open Access Journals (Sweden)

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

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.

Molecular dynamics simulations of helical antimicrobial peptides in SDS micelles: what do point mutations achieve?

DEFF Research Database (Denmark)

Khandelia, Himanshu; Kaznessis, Yiannis N

2005-01-01

We report long time scale simulations of the 18-residue helical antimicrobial peptide ovispirin-1 and its analogs novispirin-G10 and novispirin-T7 in SDS micelles. The SDS micelle serves as an economical and effective model for a cellular membrane. Ovispirin, which is initially placed along...... a micelle diameter, diffuses out to the water-SDS interface and stabilizes to an interface-bound steady state in 16.35 ns of simulation. The final conformation, orientation, and the structure of ovispirin are in good agreement with the experimentally observed properties of the peptide in presence of lipid...... bilayers. The simulation succeeds in capturing subtle differences of the membrane-bound peptide structure as predicted by solid state NMR. The novispirins also undergo identical diffusion patterns and similar final conformations. Although the final interface-bound states are similar, the simulations...

High-affinity human leucocyte antigen class I binding variola-derived peptides induce CD4(+) T cell responses more than 30 years post-vaccinia virus vaccination

DEFF Research Database (Denmark)

Wang, M.; Tang, Sheila Tuyet; Lund, Ole

2009-01-01

Interferon-gamma secreting T lymphocytes against pox virus-derived synthetic 9-mer peptides were tested by enzyme-linked immunospot in peripheral blood of individuals vaccinated with vaccinia virus more than 30 years ago. The peptides were characterized biochemically as high-affinity human leucoc...

Structural studies of polypeptides: Mechanism of immunoglobin catalysis and helix propagation in hybrid sequence, disulfide containing peptides

Energy Technology Data Exchange (ETDEWEB)

Storrs, Richard Wood [Univ. of California, Berkeley, CA (United States)

1992-08-01

Catalytic immunoglobin fragments were studied Nuclear Magnetic Resonance spectroscopy to identify amino acid residues responsible for the catalytic activity. Small, hybrid sequence peptides were analyzed for helix propagation following covalent initiation and for activity related to the protein from which the helical sequence was derived. Hydrolysis of p-nitrophenyl carbonates and esters by specific immunoglobins is thought to involve charge complementarity. The pK of the transition state analog P-nitrophenyl phosphate bound to the immunoglobin fragment was determined by ³¹P-NMR to verify the juxtaposition of a positively charged amino acid to the binding/catalytic site. Optical studies of immunoglobin mediated photoreversal of cis, syn cyclobutane thymine dimers implicated tryptophan as the photosensitizing chromophore. Research shows the chemical environment of a single tryptophan residue is altered upon binding of the thymine dimer. This tryptophan residue was localized to within 20 Å of the binding site through the use of a nitroxide paramagnetic species covalently attached to the thymine dimer. A hybrid sequence peptide was synthesized based on the bee venom peptide apamin in which the helical residues of apamin were replaced with those from the recognition helix of the bacteriophage 434 repressor protein. Oxidation of the disufide bonds occured uniformly in the proper 1-11, 3-15 orientation, stabilizing the 434 sequence in an α-helix. The glycine residue stopped helix propagation. Helix propagation in 2,2,2-trifluoroethanol mixtures was investigated in a second hybrid sequence peptide using the apamin-derived disulfide scaffold and the S-peptide sequence. The helix-stop signal previously observed was not observed in the NMR NOESY spectrum. Helical connectivities were seen throughout the S-peptide sequence. The apamin/S-peptide hybrid binded to the S-protein (residues 21-166 of ribonuclease A) and reconstituted enzymatic activity.

Structural studies of polypeptides: Mechanism of immunoglobin catalysis and helix propagation in hybrid sequence, disulfide containing peptides

Energy Technology Data Exchange (ETDEWEB)

Storrs, R.W.

1992-08-01

Catalytic immunoglobin fragments were studied Nuclear Magnetic Resonance spectroscopy to identify amino acid residues responsible for the catalytic activity. Small, hybrid sequence peptides were analyzed for helix propagation following covalent initiation and for activity related to the protein from which the helical sequence was derived. Hydrolysis of p-nitrophenyl carbonates and esters by specific immunoglobins is thought to involve charge complementarity. The pK of the transition state analog P-nitrophenyl phosphate bound to the immunoglobin fragment was determined by [sup 31]P-NMR to verify the juxtaposition of a positively charged amino acid to the binding/catalytic site. Optical studies of immunoglobin mediated photoreversal of cis, syn cyclobutane thymine dimers implicated tryptophan as the photosensitizing chromophore. Research shows the chemical environment of a single tryptophan residue is altered upon binding of the thymine dimer. This tryptophan residue was localized to within 20 [Angstrom] of the binding site through the use of a nitroxide paramagnetic species covalently attached to the thymine dimer. A hybrid sequence peptide was synthesized based on the bee venom peptide apamin in which the helical residues of apamin were replaced with those from the recognition helix of the bacteriophage 434 repressor protein. Oxidation of the disufide bonds occured uniformly in the proper 1-11, 3-15 orientation, stabilizing the 434 sequence in an [alpha]-helix. The glycine residue stopped helix propagation. Helix propagation in 2,2,2-trifluoroethanol mixtures was investigated in a second hybrid sequence peptide using the apamin-derived disulfide scaffold and the S-peptide sequence. The helix-stop signal previously observed was not observed in the NMR NOESY spectrum. Helical connectivities were seen throughout the S-peptide sequence. The apamin/S-peptide hybrid binded to the S-protein (residues 21-166 of ribonuclease A) and reconstituted enzymatic activity.

Biosynthesis of 2-aminooctanoic acid and its use to terminally modify a lactoferricin B peptide derivative for improved antimicrobial activity.

Science.gov (United States)

Almahboub, Sarah A; Narancic, Tanja; Devocelle, Marc; Kenny, Shane T; Palmer-Brown, William; Murphy, Cormac; Nikodinovic-Runic, Jasmina; O'Connor, Kevin E

2018-01-01

Terminal modification of peptides is frequently used to improve their hydrophobicity. While N-terminal modification with fatty acids (lipidation) has been reported previously, C-terminal lipidation is limited as it requires the use of linkers. Here we report the use of a biocatalyst for the production of an unnatural fatty amino acid, (S)-2-aminooctanoic acid (2-AOA) with enantiomeric excess > 98% ee and the subsequent use of 2-AOA to modify and improve the activity of an antimicrobial peptide. A transaminase originating from Chromobacterium violaceum was employed with a conversion efficiency 52-80% depending on the ratio of amino group donor to acceptor. 2-AOA is a fatty acid with amino functionality, which allowed direct C- and N-terminal conjugation respectively to an antimicrobial peptide (AMP) derived from lactoferricin B. The antibacterial activity of the modified peptides was improved by up to 16-fold. Furthermore, minimal inhibitory concentrations (MIC) of C-terminally modified peptide were always lower than N-terminally conjugated peptides. The C-terminally modified peptide exhibited MIC values of 25 μg/ml for Escherichia coli, 50 μg/ml for Bacillus subtilis, 100 μg/ml for Salmonella typhimurium, 200 μg/ml for Pseudomonas aeruginosa and 400 μg/ml for Staphylococcus aureus. The C-terminally modified peptide was the only peptide tested that showed complete inhibition of growth of S. aureus.

No-arbitrage bounds for financial scenarios

DEFF Research Database (Denmark)

Geyer, Alois; Hanke, Michael; Weissensteiner, Alex

2014-01-01

We derive no-arbitrage bounds for expected excess returns to generate scenarios used in financial applications. The bounds allow to distinguish three regions: one where arbitrage opportunities will never exist, a second where arbitrage may be present, and a third, where arbitrage opportunities...

Re-derived overclosure bound for the inert doublet model

Science.gov (United States)

Biondini, S.; Laine, M.

2017-08-01

We apply a formalism accounting for thermal effects (such as modified Sommerfeld effect; Salpeter correction; decohering scatterings; dissociation of bound states), to one of the simplest WIMP-like dark matter models, associated with an "inert" Higgs doublet. A broad temperature range T ˜ M/20 . . . M/104 is considered, stressing the importance and less-understood nature of late annihilation stages. Even though only weak interactions play a role, we find that resummed real and virtual corrections increase the tree-level overclosure bound by 1 . . . 18%, depending on quartic couplings and mass splittings.

Investigation of the antibiofilm capacity of peptide-modified stainless steel.

Science.gov (United States)

Cao, Pan; Li, Wen-Wu; Morris, Andrew R; Horrocks, Paul D; Yuan, Cheng-Qing; Yang, Ying

2018-03-01

Biofilm formation on surfaces is an important research topic in ship tribology and medical implants. In this study, dopamine and two types of synthetic peptides were designed and attached to 304 stainless steel surfaces, aiming to inhibit the formation of biofilms. A combinatory surface modification procedure was applied in which dopamine was used as a coupling agent, allowing a strong binding ability with the two peptides. X-ray photoelectron spectroscopy (XPS), elemental analysis, contact angle measurement and surface roughness test were used to evaluate the efficiency of the peptide modification. An antibiofilm assay against Staphylococcus aureus was conducted to validate the antibiofilm capacity of the peptide-modified stainless steel samples. XPS analysis confirmed that the optimal dopamine concentration was 40 µg ml -1 in the coupling reaction. Element analysis showed that dopamine and the peptides had bound to the steel surfaces. The robustness assay of the modified surface demonstrated that most peptide molecules had bound on the surface of the stainless steel firmly. The contact angle of the modified surfaces was significantly changed. Modified steel samples exhibited improved antibiofilm properties in comparison to untreated and dopamine-only counterpart, with the peptide 1 modification displaying the best antibiofilm effect. The modified surfaces showed antibacterial capacity. The antibiofilm capacity of the modified surfaces was also surface topography sensitive. The steel sample surfaces polished with 600# sandpaper exhibited stronger antibiofilm capacity than those polished with other types of sandpapers after peptide modification. These findings present valuable information for future antifouling material research.

Positivity bounds for Sivers functions

International Nuclear Information System (INIS)

Kang Zhongbo; Soffer, Jacques

2011-01-01

We generalize a positivity constraint derived initially for parity-conserving processes to the parity-violating ones, and use it to derive non-trivial bounds on several Sivers functions, entering in the theoretical description of single spin asymmetry for various processes.

Antiviral activity of a Bacillus sp: P34 peptide against pathogenic viruses of domestic animals

Directory of Open Access Journals (Sweden)

Débora Scopel e Silva

2014-09-01

Full Text Available P34 is an antimicrobial peptide produced by a Bacillus sp. strain isolated from the intestinal contents of a fish in the Brazilian Amazon basin with reported antibacterial activity. The aim of this work was to evaluate the peptide P34 for its in vitro antiviral properties against canine adenovirus type 2 (CAV-2, canine coronavirus (CCoV, canine distemper virus (CDV, canine parvovirus type 2 (CPV-2, equine arteritis virus (EAV, equine influenza virus (EIV, feline calicivirus (FCV and feline herpesvirus type 1 (FHV-1. The results showed that the peptide P34 exhibited antiviral activity against EAV and FHV-1. The peptide P34 inhibited the replication of EAV by 99.9% and FHV-1 by 94.4%. Virucidal activity was detected only against EAV. When P34 and EAV were incubated for 6 h at 37 °C the viral titer reduced from 10(4.5 TCID50 to 10(2.75 TCID50, showing a percent of inhibition of 98.6%. In conclusion, our results demonstrated that P34 inhibited EAV and FHV-1 replication in infected cell cultures and it showed virucidal activity against EAV. Since there is documented resistance to the current drugs used against herpesviruses and there is no treatment for equine viral arteritis, it is advisable to search for new antiviral compounds to overcome these infections.

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

Intrinsic Toxin-Derived Peptides Destabilize and Inactivate Clostridium difficile TcdB

Directory of Open Access Journals (Sweden)

Jason L. Larabee

2017-05-01

Full Text Available Clostridium difficile infection (CDI is a major cause of hospital-associated, antibiotic-induced diarrhea, which is largely mediated by the production of two large multidomain clostridial toxins, TcdA and TcdB. Both toxins coordinate the action of specific domains to bind receptors, enter cells, and deliver a catalytic fragment into the cytosol. This results in GTPase inactivation, actin disassembly, and cytotoxicity. TcdB in particular has been shown to encode a region covering amino acids 1753 to 1851 that affects epitope exposure and cytotoxicity. Surprisingly, studies here show that several peptides derived from this region, which share the consensus sequence 1769NVFKGNTISDK1779, protect cells from the action of TcdB. One peptide, PepB2, forms multiple interactions with the carboxy-terminal region of TcdB, destabilizes TcdB structure, and disrupts cell binding. We further show that these effects require PepB2 to form a higher-order polymeric complex, a process that requires the central GN amino acid pair. These data suggest that TcdB1769–1779 interacts with repeat sequences in the proximal carboxy-terminal domain of TcdB (i.e., the CROP domain to alter the conformation of TcdB. Furthermore, these studies provide insights into TcdB structure and functions that can be exploited to inactivate this critical virulence factor and ameliorate the course of CDI.

Use of a Phage-Display Method to Identify Peptides that Bind to a Tin Oxide Nanosheets.

Science.gov (United States)

Nakazawa, Hikaru; Seta, Yasuko; Hirose, Tatsuya; Masuda, Yoshitake; Umetsu, Mitsuo

2018-01-01

Nanosheets of SnO2 which an n-type semiconductor with a rutile-type crystalline structure are predominantly used as gas sensors. SnO2 nanosheets have a tetragonal crystal structure where growth along the c-axis is suppressed to form a sheet. The major exposed facets of SnO2 nanosheets have {110}, {101} and {211} crystal planes along the a-axis, with the reduced {110} surface having a particularly high surface energy. Identifying peptides that bind to specific crystal planes by using peptide phage-display approach will increase the potential applications of metal oxide nanomaterials by fusing proteins with desirable active sites to peptides that adsorb at high density on the major exposed crystal plane of nanosheets. It may be possible to construct highly sensitive biosensors. The main objective of the present study is to identify peptides that adsorb preferentially to a SnO2 nanosheet by using peptide-phage display approach. Four milligrams of SnO2 nanosheet were mixed with 1011 plaque-forming units of Ph.D.-12 Phage Display Peptide Library. Phage-bound nanosheet particles were washed 10 times with 1 mL of phosphatebuffered saline containing 0.5% Tween 20. Phages bound to the nanosheet were eluted with three different buffers: (1) high-salt buffer containing 2 M NaCl (pH 7.5); (2) acidic buffer containing 200 mM Gly-HCl (pH 2.2); and (3) high-phosphate-ion buffer containing 500 mM NaH2PO4 (pH 7.5). The eluted phages were subjected to four or five rounds of biopanning. At each round, individual plaques were picked from the plates, and the amino acid sequences of the peptides were identified by DNA sequencing. The identified SnO2-binding peptides labeled with fluorescein isothiocyanate were synthesized. Adsorption isotherms were constructed at peptide concentrations ranging from 0.25 to 2.0 µM with 4mg of nanomaterials. We were determined the sequences of 11 clones with the high-salt buffer, 7 with the high-phosphateion buffers, and 6 with the acidic buffer and

Solution Structure of LXXLL-related Cofactor Peptide of Orphan Nuclear Receptor FTZ-F1

International Nuclear Information System (INIS)

Yun, Ji Hye; Lee, Chul Jin; Jung, Jin Won; Lee, Weon Tae

2012-01-01

Functional interaction between Drosophila orphan receptor FTZ-F1 (NR5A3) and a segmentation gene product fushi tarazu (FTZ) is crucial for regulating genes related to define the identities of alternate segmental regions in the Drosophila embryo. FTZ binding to the ligand-binding domain (LBD) of FTZ-F1 is of essence in activating its transcription process. We determined solution structures of the cofactor peptide (FTZ PEP ) derived from FTZ by NMR spectroscopy. The cofactor peptide showed a nascent helical conformation in aqueous solution, however, the helicity was increased in the presence of TFE. Furthermore, FTZ PEP formed α- helical conformation upon FTZ-F1 binding, which provides a receptor bound structure of FTZ PEP . The solution structure of FTZ PEP in the presence of FTZ-F1 displays a long stretch of the α-helix with a bend in the middle of helix

Solution Structure of LXXLL-related Cofactor Peptide of Orphan Nuclear Receptor FTZ-F1

Energy Technology Data Exchange (ETDEWEB)

Yun, Ji Hye; Lee, Chul Jin; Jung, Jin Won; Lee, Weon Tae [Yonsei University, Seoul (Korea, Republic of)

2012-02-15

Functional interaction between Drosophila orphan receptor FTZ-F1 (NR5A3) and a segmentation gene product fushi tarazu (FTZ) is crucial for regulating genes related to define the identities of alternate segmental regions in the Drosophila embryo. FTZ binding to the ligand-binding domain (LBD) of FTZ-F1 is of essence in activating its transcription process. We determined solution structures of the cofactor peptide (FTZ{sup PEP}) derived from FTZ by NMR spectroscopy. The cofactor peptide showed a nascent helical conformation in aqueous solution, however, the helicity was increased in the presence of TFE. Furthermore, FTZ{sup PEP} formed α- helical conformation upon FTZ-F1 binding, which provides a receptor bound structure of FTZ{sup PEP}. The solution structure of FTZ{sup PEP} in the presence of FTZ-F1 displays a long stretch of the α-helix with a bend in the middle of helix.

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

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.

Optimization of hydrolysis conditions, isolation, and identification of neuroprotective peptides derived from seahorse Hippocampus trimaculatus.

Science.gov (United States)

Pangestuti, Ratih; Ryu, Bomi; Himaya, Swa; Kim, Se-Kwon

2013-08-01

Hippocampus trimaculatus is one of the most heavily traded seahorse species for traditional medicine purposes in many countries. In the present study, we showed neuroprotective effects of peptide derived from H. trimaculatus against amyloid-β42 (Aβ42) toxicity which are central to the pathogenesis of Alzheimer's diseases (AD). Firstly, H. trimaculatus was separately hydrolyzed by four different enzymes and tested for their protective effect on Aβ42-induced neurotoxicity in differentiated PC12 cells. Pronase E hydrolysate exerted highest protection with cell viability value of 88.33 ± 3.33 %. Furthermore, we used response surface methodology to optimize pronase E hydrolysis conditions and found that temperature at 36.69 °C with the hydrolysis time 20.01 h, enzyme to substrate (E/S) ratio of 2.02 % and pH 7.34 were the most optimum conditions. Following several purification steps, H. trimaculatus-derived neuroprotective peptides (HTP-1) sequence was identified as Gly-Thr-Glu-Asp-Glu-Leu-Asp-Lys (906.4 Da). HTP-1 protected PC12 cells from Aβ42-induced neuronal death with the cell viability value of 85.52 ± 2.22 % and up-regulated pro-survival gene (Bcl-2) expressions. These results suggest that HTP-1 has the potential to be used in treatment of neurodegenerative diseases, particularly AD. Identification, characterization, and synthesis of bioactive components derived from H. trimaculatus have the potential to replace or at least complement the use of seahorse as traditional medicine, which further may become an approach to minimize seahorse exploitation in traditional medicine.

A family of cell-adhering peptides homologous to fibrinogen C-termini

International Nuclear Information System (INIS)

Levy-Beladev, Liron; Levdansky, Lilia; Gaberman, Elena; Friedler, Assaf; Gorodetsky, Raphael

2010-01-01

Research highlights: → Cell-adhesive sequences homologous to fibrinogen C-termini exist in other proteins. → The extended homologous cell-adhesive C-termini peptides family is termed Haptides. → In membrane-like environment random coiled Haptides adopt a helical conformation. → Replacing positively charged residues with alanine reduces Haptides activity. -- Abstract: A family of cell-adhesive peptides homologous to sequences on different chains of fibrinogen was investigated. These homologous peptides, termed Haptides, include the peptides Cβ, preCγ, and CαE, corresponding to sequences on the C-termini of fibrinogen chains β, γ, and αE, respectively. Haptides do not affect cell survival and rate of proliferation of the normal cell types tested. The use of new sensitive assays of cell adhesion clearly demonstrated the ability of Haptides, bound to inert matrices, to mediate attachment of different matrix-dependent cell types including normal fibroblasts, endothelial, and smooth muscle cells. Here we present new active Haptides bearing homologous sequences derived from the C-termini of other proteins, such as angiopoietin 1 and 2, tenascins C and X, and microfibril-associated glycoprotein-4. The cell adhesion properties of all the Haptides were found to be associated mainly with their 11 N-terminal residues. Mutated preCγ peptides revealed that positively charged residues account for their attachment effect. These results suggest a mechanism of direct electrostatic interaction of Haptides with the cell membrane. The extended Haptides family may be applied in modulating adhesion of cells to scaffolds for tissue regeneration and for enhancement of nanoparticulate transfection into cells.

NMR structures of anti-HIV D-peptides derived from the N-terminus of viral chemokine vMIP-II

International Nuclear Information System (INIS)

Mori, Mayuko; Liu Dongxiang; Kumar, Santosh; Huang Ziwei

2005-01-01

The viral macrophage inflammatory protein-II (vMIP-II) encoded by Kaposi's sarcoma-associated herpesvirus has unique biological activities in that it blocks the cell entry by several different human immunodeficiency virus type 1 (HIV-1) strains via chemokine receptors including CXCR4 and CCR5. In this paper, we report the solution structure of all-D-amino acid peptides derived from the N-terminus of vMIP-II, which have been shown to have strong CXCR4 binding activity and potently inhibit HIV-1 entry via CXCR4, by using long mixing time two-dimensional nuclear Overhauser enhancement spectroscopy experiments. Both of all-D-peptides vMIP-II (1-10) and vMIP-II (1-21), which are designated as DV3 and DV1, respectively, have higher CXCR4 binding ability than their L-peptide counterparts. They are partially structured in aqueous solution, displaying a turn-like structure over residues 5-8. The small temperature coefficients of His-6 amide proton for both peptides also suggest the formation of a small hydrophobic pocket centered on His-6. The structural features of DV3 are very similar to the reported solution structure of all-L-peptide vMIP-II (1-10) [M.P. Crump, E. Elisseeva, J. Gong, I. Clark-Lewis, B.D. Sykes, Structure/function of human herpesvirus-8 MIP-II (1-71) and the antagonist N-terminal segment (1-10), FEBS Lett. 489 (2001) 171], which is consistent with the notion that D- and L-enantiomeric peptides can adopt mirror image conformations. The NMR structures of the D-peptides provide a structural basis to understand their mechanism of action and design new peptidomimetic analogs to further explore the structure-activity relationship of D-peptide ligand binding to CXCR4

Acute ingestion of a novel whey-derived peptide improves vascular endothelial responses in healthy individuals: a randomized, placebo controlled trial

Directory of Open Access Journals (Sweden)

Kupchak Brian R

2009-07-01

Full Text Available Abstract Background Whey protein is a potential source of bioactive peptides. Based on findings from in vitro experiments indicating a novel whey derived peptide (NOP-47 increased endothelial nitric oxide synthesis, we tested its effects on vascular function in humans. Methods A randomized, placebo-controlled, crossover study design was used. Healthy men (n = 10 and women (n = 10 (25 ± 5 y, BMI = 24.3 ± 2.3 kg/m2 participated in two vascular testing days each preceded by 2 wk of supplementation with a single dose of 5 g/day of a novel whey-derived peptide (NOP-47 or placebo. There was a 2 wk washout period between trials. After 2 wk of supplementation, vascular function in the forearm and circulating oxidative stress and inflammatory related biomarkers were measured serially for 2 h after ingestion of 5 g of NOP-47 or placebo. Macrovascular and microvascular function were assessed using brachial artery flow mediated dilation (FMD and venous occlusion strain gauge plethysmography. Results Baseline peak FMD was not different for Placebo (7.7% and NOP-47 (7.8%. Placebo had no effect on FMD at 30, 60, and 90 min post-ingestion (7.5%, 7.2%, and 7.6%, respectively whereas NOP-47 significantly improved FMD responses at these respective postprandial time points compared to baseline (8.9%, 9.9%, and 9.0%; P P = 0.008 for time × trial interaction. Plasma myeloperoxidase was increased transiently by both NOP-47 and placebo, but there were no changes in markers inflammation. Plasma total nitrites/nitrates significantly decreased over the 2 hr post-ingestion period and were lower at 120 min after placebo (-25% compared to NOP-47 (-18%. Conclusion These findings indicate that supplementation with a novel whey-derived peptide in healthy individuals improves vascular function.

Maize EMBRYO SAC family peptides interact differentially with pollen tubes and fungal cells.

Science.gov (United States)

Woriedh, Mayada; Merkl, Rainer; Dresselhaus, Thomas

2015-08-01

EMBRYO SAC1-4 (ES1-4) peptides belong to the defensin subgroup of cysteine-rich peptides known to mediate pollen tube burst in Zea mays (maize). ES1-4 are reported here to also be capable of inhibiting germination and growth of the maize fungal pathogens Fusarium graminearum and Ustilago maydis at higher concentrations. Dividing the peptides into smaller pieces showed that a 15-amino-acid peptide located in a highly variable loop region lacking similarity to other defensins or defensin-like peptides binds to maize pollen tube surfaces, causing swelling prior to burst. This peptide fragment and a second conserved neighbouring fragment showed suppression of fungal germination and growth. The two peptides caused swelling of fungal cells, production of reactive oxygen species, and finally the formation of big vacuoles prior to burst at high peptide concentration. Furthermore, peptide fragments were found to bind differently to fungal cells. In necrotrophic F. graminearum, a peptide fragment named ES-d bound only at cell surfaces whereas the peptide ES-c bound at cell surfaces and also accumulated inside cells. Conversely, in biotrophic U. maydis, both peptide fragments accumulated inside cells, but, if applied at higher concentration, ES-c but not ES-d accumulated mainly in vacuoles. Mapping of peptide interaction sites identified amino acids differing in pollen tube burst and fungal response reactions. In summary, these findings indicate that residues targeting pollen tube burst in maize are specific to the ES family, while residues targeting fungal growth are conserved within defensins and defensin-like peptides. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Peptides in melanoma therapy.

Science.gov (United States)

Mocellin, Simone

2012-01-01

Peptides derived from tumor associated antigens can be utilized to elicit a therapeutically effective immune response against melanoma in experimental models. However, patient vaccination with peptides - although it is often followed by the induction of melanoma- specific T lymphocytes - is rarely associated with tumor response of clinical relevance. In this review I summarize the principles of peptide design as well as the results so far obtained in the clinical setting while treating cutaneous melanoma by means of this active immunotherapy strategy. I also discuss some immunological and methodological issues that might be helpful for the successful development of peptide-based vaccines.

Universal bounds in even-spin CFTs

Energy Technology Data Exchange (ETDEWEB)

Qualls, Joshua D. [Department of Physics, National Taiwan University,Taipei, Taiwan (China)

2015-12-01

We prove using invariance under the modular S− and ST−transformations that every unitary two-dimensional conformal field theory (CFT) having only even-spin primary operators (with no extended chiral algebra and with right- and left-central charges c,c̃>1) contains a primary operator with dimension Δ{sub 1} satisfying 0<Δ{sub 1}<((c+c̃)/24)+0.09280…. After deriving both analytical and numerical bounds, we discuss how to extend our methods to bound higher conformal dimensions before deriving lower and upper bounds on the number of primary operators in a given energy range. Using the AdS{sub 3}/CFT{sub 2} dictionary, the bound on Δ{sub 1} proves the lightest massive excitation in appropriate theories of 3D matter and gravity with cosmological constant Λ<0 can be no heavier than 1/8G{sub N}+O(√(−Λ)); the bounds on the number of operators are related via AdS/CFT to the entropy of states in the dual gravitational theory. In the flat-space approximation, the limiting mass is exactly that of the lightest BTZ black hole.

Lower Bounds to the Reliabilities of Factor Score Estimators.

Science.gov (United States)

Hessen, David J

2016-10-06

Under the general common factor model, the reliabilities of factor score estimators might be of more interest than the reliability of the total score (the unweighted sum of item scores). In this paper, lower bounds to the reliabilities of Thurstone's factor score estimators, Bartlett's factor score estimators, and McDonald's factor score estimators are derived and conditions are given under which these lower bounds are equal. The relative performance of the derived lower bounds is studied using classic example data sets. The results show that estimates of the lower bounds to the reliabilities of Thurstone's factor score estimators are greater than or equal to the estimates of the lower bounds to the reliabilities of Bartlett's and McDonald's factor score estimators.

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.

Residual DNA-bound proteins are a source of in vitro transcription inhibitor peptides

International Nuclear Information System (INIS)

Venanzi, F.M.

1989-01-01

Enzymatic breakdown of residual proteins occurs at mild alkaline pH (pH optimum 8.5) as monitored by using radioiodinated, purified genomic DNA from calf thymus. These DNA fibers also possess a differential ability to hydrolyze added exogenous small and linker histones. The results described argue strongly that a putative protease activity, co-purified with DNA, is the source of short chain peptides which inhibit transcription in vitro. Therefore, we propose that RNA repressor peptides must be of higher molecular weight than previously reported

Antimicrobial Activity of Truncated and Polyvalent Peptides Derived from the FKCRRQWQWRMKKGLA Sequence against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923

Directory of Open Access Journals (Sweden)

Nataly de Jesús Huertas

2017-06-01

Full Text Available Peptides derived from LfcinB were designed and synthesized, and their antibacterial activity was tested against Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 25923. Specifically, a peptide library was constructed by systemically removing the flanking residues (N or C-terminal of Lfcin 17–31 (17FKCRRWQWRMKKLGA31, maintaining in all peptides the 20RRWQWR25 sequence that corresponds to the minimal antimicrobial motif. For this research, also included were (i a peptide containing an Ala instead of Cys ([Ala19]-LfcinB 17–31 and (ii polyvalent peptides containing the RRWQWR sequence and a non-natural amino acid (aminocaproic acid. We established that the lineal peptides LfcinB 17–25 and LfcinB 17–26 exhibited the greatest activity against E. coli ATCC 25922 and S. aureus ATCC 25923, respectively. On the other hand, polyvalent peptides, a dimer and a tetramer, exhibited the greatest antibacterial activity, indicating that multiple copies of the sequence increase the activity. Our results suggest that the dimeric and tetrameric sequence forms potentiate the antibacterial activity of lineal sequences that have exhibited moderate antibacterial activity.

A Two-Piece Derivative of a Group I Intron RNA as a Platform for Designing Self-Assembling RNA Templates to Promote Peptide Ligation

Directory of Open Access Journals (Sweden)

Takahiro Tanaka

2012-01-01

Full Text Available Multicomponent RNA-peptide complexes are attractive from the viewpoint of artificial design of functional biomacromolecular systems. We have developed self-folding and self-assembling RNAs that serve as templates to assist chemical ligation between two reactive peptides with RNA-binding capabilities. The design principle of previous templates, however, can be applied only to limited classes of RNA-binding peptides. In this study, we employed a two-piece derivative of a group I intron RNA from the Tetrahymena large subunit ribosomal RNA (LSU rRNA as a platform for new template RNAs. In this group I intron-based self-assembling platform, modules for the recognition of substrate peptides can be installed independently from modules holding the platform structure. The new self-assembling platform allows us to expand the repertoire of substrate peptides in template RNA design.

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

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.

Biosynthesis of cardiac natriuretic peptides

DEFF Research Database (Denmark)

Goetze, Jens Peter

2010-01-01

Cardiac-derived peptide hormones were identified more than 25 years ago. An astonishing amount of clinical studies have established cardiac natriuretic peptides and their molecular precursors as useful markers of heart disease. In contrast to the clinical applications, the biogenesis of cardiac...... peptides has only been elucidated during the last decade. The cellular synthesis including amino acid modifications and proteolytic cleavages has proven considerably more complex than initially perceived. Consequently, the elimination phase of the peptide products in circulation is not yet well....... An inefficient post-translational prohormone maturation will also affect the biology of the cardiac natriuretic peptide system. This review aims at summarizing the myocardial synthesis of natriuretic peptides focusing on B-type natriuretic peptide, where new data has disclosed cardiac myocytes as highly...

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.

Comparative analysis of biological activities of Der p I-derived peptides on Fc epsilon receptor-bearing cells from Dermatophagoides pteronyssinus-sensitive patients.

Science.gov (United States)

Jeannin, P; Pestel, J; Bossus, M; Lassalle, P; Tartar, A; Tonnel, A B

1993-01-01

The ability of four uncoupled synthetic peptides (p52-71, p117-133, p176-187, p188-199) derived from Der p I, a major allergen from the house dust mite Dermatophagoides pteronyssinus (Dpt) to stimulate Fc epsilon R+ cells from Dpt-sensitive patients was comparatively analysed. Each free peptide may specifically stimulate basophils (Fc epsilon RI+ cells) and platelets (Fc epsilon RII+ cells) from patients with significant levels of anti-Der p I IgE antibodies; p52-71 and p117-133 appear the best cell stimulation inducers. Both concentration-dependent biological activities of Der p I-peptide on Fc epsilon R+ cells are enhanced by coupling peptide to a carrier (as human serum albumin). Interestingly each Der p I-sensitive patient tested presents an individual pattern of response to peptide. Thus, from our results it appears that different Der p I sequences could be involved in the immune response to Der p I. PMID:7682161

Comparative analysis of biological activities of Der p I-derived peptides on Fc epsilon receptor-bearing cells from Dermatophagoides pteronyssinus-sensitive patients.

Science.gov (United States)

Jeannin, P; Pestel, J; Bossus, M; Lassalle, P; Tartar, A; Tonnel, A B

1993-04-01

The ability of four uncoupled synthetic peptides (p52-71, p117-133, p176-187, p188-199) derived from Der p I, a major allergen from the house dust mite Dermatophagoides pteronyssinus (Dpt) to stimulate Fc epsilon R+ cells from Dpt-sensitive patients was comparatively analysed. Each free peptide may specifically stimulate basophils (Fc epsilon RI+ cells) and platelets (Fc epsilon RII+ cells) from patients with significant levels of anti-Der p I IgE antibodies; p52-71 and p117-133 appear the best cell stimulation inducers. Both concentration-dependent biological activities of Der p I-peptide on Fc epsilon R+ cells are enhanced by coupling peptide to a carrier (as human serum albumin). Interestingly each Der p I-sensitive patient tested presents an individual pattern of response to peptide. Thus, from our results it appears that different Der p I sequences could be involved in the immune response to Der p I.

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

Alpha-amidated peptides derived from pro-opiomelanocortin in normal human pituitary

DEFF Research Database (Denmark)

Fenger, M; Johnsen, A H

1988-01-01

Normal human pituitaries were extracted in boiling water and acetic acid, and the alpha-amidated peptide products of pro-opiomelanocortin (POMC), alpha-melanocyte-stimulating hormone (alpha MSH), gamma-melanocyte-stimulating hormone (gamma 1MSH), and amidated hinge peptide (HP-N), as well...... (ACTH)-(1-39), ACTH-(1-14) and alpha MSH immunoreactivity]. alpha MSH and ACTH-(1-14) were only present in non- or mono-acetylated forms. Only large forms of gamma 1MSH and gamma 2MSH were present in partly glycosylated states. The hinge peptides were amidated to an extent two to three orders...... amidated POMC-related peptides are present in normal human pituitary. It also shows that cleavage in vivo at all dibasic amino acids but one, takes place at the N-terminal POMC region; the exception is at the POMC-(49-50) N-terminal of the gamma MSH sequence. The pattern of peptides produced suggests...

Cardioprotective peptides from marine sources.

Science.gov (United States)

Harnedy, Padraigín A; FitzGerald, Richard J

2013-05-01

Elevated blood pressure or hypertension is one of the fastest growing health problems worldwide. Although the etiology of essential hypertension has a genetic component, dietary factors play an important role. With the high costs and adverse side-effects associated with synthetic antihypertensive drugs and the awareness of the link between diet and health there has been increased focus on identification of food components that may contribute to cardiovascular health. In recent years special interest has been paid to the cardioprotective activity of peptides derived from food proteins including marine proteins. These peptides are latent within the sequence of the parent protein and only become active when released by proteolytic digestion during gastrointestinal digestion or through food processing. Current data on antihypertensive activity of marine-derived protein hydrolysates/peptides in animal and human studies is reviewed herein. Furthermore, products containing protein hydrolysates/peptides from marine origin with antihypertensive effects are discussed.

Evaluation of single amino acid chelate derivatives and regioselective radiolabelling of a cyclic peptide for the urokinase plasminogen activator receptor

Energy Technology Data Exchange (ETDEWEB)

Armstrong, Andrea F.; Lemon, Jennifer A. [McMaster Institute for Applied Radiation Sciences, McMaster University, ON, L8S 4M1 (Canada); Czorny, Shannon K. [McMaster Institute for Applied Radiation Sciences, McMaster University, ON, L8S 4M1 (Canada); Juravinski Cancer Centre, Hamilton, ON, L8V 5C2 (Canada); Singh, Gurmit [Juravinski Cancer Centre, Hamilton, ON, L8V 5C2 (Canada); Valliant, John F. [Department of Chemistry, McMaster University, Hamilton, ON, L8S 4M1 (Canada); Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, ON, L8S 4M1 (Canada)], E-mail: valliant@mcmaster.ca

2009-11-15

Introduction: The aim of this work was to investigate the relative radiolabelling kinetics and affinity of a series of ligands for the [{sup 99m}Tc(CO){sub 3}]{sup +} core, both in the absence and in the presence of competing donors. This information was used to select a suitable ligand for radiolabelling complex peptide-based targeting vectors in high yield under mild conditions. Methods: A series of {alpha}-N-Fmoc-protected lysine derivatives bearing two heterocyclic donor groups at the {epsilon}-amine (, 2-pyridyl; , quinolyl; , 6-methoxy-2-pyridyl; 1d, 2-thiazolyl; 1e, N-methylimidazolyl; , 3-pyridyl) were synthesized and labelled with {sup 99m}Tc. A resin-capture purification strategy for the separation of residual ligand from the radiolabelled product was also developed. The binding affinities of targeted peptides 4, 5a and 5b for uPAR were determined using flow cytometry. Results: Variable temperature radiolabelling reactions using - and [{sup 99m}Tc(CO){sub 3}]{sup +} revealed optimal kinetics and good selectivity for compounds and 1d; in the case of , 1d, and 1e, the labelling can be conducted at ambient temperature. The utility of this class of ligands was further demonstrated by the radiolabelling of a cyclic peptide that is known to target the serine protease receptor uPAR; essentially quantitative incorporation of {sup 99m}Tc occurred exclusively at the SAAC site, despite the presence of a His residue, and without disruption of the disulfide bond. Conclusion: A series of single amino acid chelate (SAAC) ligands have been evaluated for their ability to incorporate {sup 99m}Tc into peptides. The lead agent to emerge from this work is the thiazole SAAC derivative 1d which has demonstrated the ability to regioselectively label the widest range of peptides.

A neural cell adhesion molecule-derived peptide reduces neuropathological signs and cognitive impairment induced by Abeta25-35

DEFF Research Database (Denmark)

Klementiev, B; Novikova, T; Novitskaya, V

2007-01-01

death and brain atrophy in response to Abeta25-35. Finally, the Abeta25-35-administration led to a reduced short-term memory as determined by the social recognition test. A synthetic peptide termed FGL derived from the neural cell adhesion molecule (NCAM) was able to prevent or, if already manifest......, strongly reduce all investigated signs of Abeta25-35-induced neuropathology and cognitive impairment. The FGL peptide was recently demonstrated to be able to cross the blood-brain-barrier. Accordingly, we found that the beneficial effects of FGL were achieved not only by intracisternal, but also...... and cognitive impairment involves the modulation of intracellular signal-transduction mediated through GSK3beta....

Generation of functional HLA-DR*1101 tetramers receptive for loading with pathogen or tumour derived synthetic peptides

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Protti Maria

2005-12-01

Full Text Available Abstract Background MHC class I-peptide tetramers are currently utilised to characterize CD8+ T cell responses at single cell level. The generation and use of MHC class II tetramers to study antigen-specific CD4+ T cells appears less straightforward. Most MHC class II tetramers are produced with a homogeneously built-in peptide, reducing greatly their flexibility of use. We attempted the generation of "empty" functional HLA-DR*1101 tetramers, receptive for loading with synthetic peptides by incubation. No such reagent is in fact available for this HLA-DR allele, one of the most frequent in the Caucasian population. Results We compared soluble MHC class II-immunoglobulin fusion proteins (HLA-DR*1101-Ig with soluble MHC class II protein fused with an optimised Bir site for enzymatic biotynilation (HLA-DR*1101-Bir, both produced in insect cells. The molecules were multimerised by binding fluorochrome-protein A or fluorochrome-streptavidin, respectively. We find that HLA-DR*1101-Bir molecules are superior to the HLA-DR*1101-Ig ones both in biochemical and functional terms. HLA-DR*1101-Bir molecules can be pulsed with at least three different promiscuous peptide epitopes, derived from Tetanus Toxoid, influenza HA and the tumour associated antigen MAGE-3 respectively, to stain specific CD4+ T cells. Both staining temperature and activation state of CD4+ T cells are critical for the binding of peptide-pulsed HLA-DR*1101-Bir to the cognate TCR. Conclusion It is therefore possible to generate a soluble recombinant HLA-DR*1101 backbone that is receptive for loading with different peptides to stain specific CD4+ T cells. As shown for other HLA-DR alleles, we confirm that not all the strategies to produce soluble HLA-DR*1101 multimers are equivalent.

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

Dynamics of lipid layers with/without bounded antimicrobial peptide halictine-1

Czech Academy of Sciences Publication Activity Database

Tesař, A.; Kopecký, V. Jr.; Kočišová, E.; Bednárová, Lucie

2017-01-01

Roč. 93, Nov (2017), s. 42-51 ISSN 0924-2031 R&D Projects: GA ČR GAP208/10/0376 Institutional support: RVO:61388963 Keywords : antibacterial peptide * halictine * liposome * phospholipid bilayer * infrared spectroscopy * attenuated total reflection Subject RIV: BO - Biophysics OBOR OECD: Biophysics Impact factor: 1.740, year: 2016

Production and characterization of peptide antibodies

DEFF Research Database (Denmark)

Trier, Nicole Hartwig; Hansen, Paul Robert; Houen, Gunnar

2012-01-01

Proteins are effective immunogens for generation of antibodies. However, occasionally the native protein is known but not available for antibody production. In such cases synthetic peptides derived from the native protein are good alternatives for antibody production. These peptide antibodies...... are powerful tools in experimental biology and are easily produced to any peptide of choice. A widely used approach for production of peptide antibodies is to immunize animals with a synthetic peptide coupled to a carrier protein. Very important is the selection of the synthetic peptide, where factors......, including solid-phase peptide-carrier conjugation and peptide-carrier conjugation in solution. Upon immunization, adjuvants such as Al(OH)(3) are added together with the immunogenic peptide-carrier conjugate, which usually leads to high-titred antisera. Following immunization and peptide antibody...

Impact of the antimicrobial peptide Novicidin on membrane structure and integrity

DEFF Research Database (Denmark)

Nielsen, Søren B; Otzen, Daniel Erik

2010-01-01

We have studied the impact of an 18-residue cationic antimicrobial peptide Novicidin (Nc) on the structure and integrity of partially anionic lipid membranes using oriented circular dichroism (OCD), quartz crystal microbalance with dissipation (QCM-D), dual polarization interferometry (DPI......), calcein dye leakage and fluorescence spectroscopy. OCD consistently showed that Nc is bound in an alpha-helical, surface bound state over a range of peptide to lipid (P/L) ratios up to approximately 1:15. Realignment of Nc at higher P/L ratios correlates to loss of membrane integrity as shown by Laurdan...... concentration, probably through formation of transient pores or transient disruption of the membrane integrity, followed by more extensive membrane disintegration at higher P/L ratios....

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

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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.

The Paradox of Feline Coronavirus Pathogenesis: A Review

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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.

Experimental myositis inducible with transfer of dendritic cells presenting a skeletal muscle C protein-derived CD8 epitope peptide.

Science.gov (United States)

Okiyama, Naoko; Hasegawa, Hisanori; Oida, Takatoku; Hirata, Shinya; Yokozeki, Hiroo; Fujimoto, Manabu; Miyasaka, Nobuyuki; Kohsaka, Hitoshi

2015-07-01

It is suggested that polymyositis, an autoimmune inflammatory myopathy, is mediated by autoaggressive CD8 T cells. Skeletal muscle C protein is a self-antigen that induces C protein-induced myositis, a murine model of polymyositis. To establish a new murine model of myositis inducible with a single CD8 T-cell epitope peptide that derives from the C protein, three internet-based prediction systems were employed to identify 24 candidate peptides of the immunogenic fragment of the C protein and bind theoretically to major histocompatibility complex class I molecules of C57BL/6 (B6) mice. RMA-S cell assay revealed that a HILIYSDV peptide, amino acid position 399-406 of the C protein, had the highest affinity to the H2-K(b) molecules. Transfer of mature bone marrow-derived dendritic cells pulsed with HILIYSDV induced myositis in naive B6 mice. This myositis was suppressed by anti-CD8-depleting antibodies but not by anti-CD4-depleting antibodies. Because this myositis model is mediated by CD8 T cells independently of CD4 T cells, it should be a useful tool to investigate pathology of polymyositis and develop therapies targeting CD8 T cells. © The Japanese Society for Immunology. 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Structure of HLA-A*1101 in complex with a hepatitis B peptide homologue

DEFF Research Database (Denmark)

Blicher, Thomas; Kastrup, Jette Sandholm; Pedersen, Lars Østergaard

2006-01-01

A high-resolution structure of the human MHC-I molecule HLA-A*1101 is presented in which it forms a complex with a sequence homologue of a peptide that occurs naturally in hepatitis B virus DNA polymerase. The sequence of the bound peptide is AIMPARFYPK, while that of the corresponding natural...

A geometric bound on F-term inflation

NARCIS (Netherlands)

Borghese, Andrea; Roest, Diederik; Zavala, Ivonne

We discuss a general bound on the possibility to realise inflation in any minimal supergravity with F-terms. The derivation crucially depends on the sGoldstini, the scalar field directions that are singled out by spontaneous supersymmetry breaking. The resulting bound involves both slow-roll

The lactoferricin B-derived peptide, LfB17-34, induces melanogenesis in B16F10 cells.

Science.gov (United States)

Huang, Hsiu-Chin; Lin, Hsuan; Huang, Min-Chuan

2017-03-01

Lactoferricin B (LfcinB), a peptide of bovine lactoferrin (LfB), exhibits multiple biological functions, including antimicrobial, antiviral, antioxidant and immunomodulatory activities. However, the role of LfcinB-related peptides in melanogenesis remains unclear. In this study, a set of five LfcinB-related peptides was examined. We found that LfB17‑34, an 18-mer LfcinB-derived peptide, increased melanogenesis in B16F10 melanoma cells without significantly affecting cell viability. LfB17‑34 increased in vitro tyrosinase activity and melanin content in a dose-dependent manner. The results of RT-qPCR and western blot analyses showed that LfB17‑34 increased the mRNA and protein expression of tyrosinase and tyrosinase-related protein 1 (Trp1). Moreover, LfB17‑34 inhibited the phosphorylation of MAPK/Erk, but not p38 and Akt, and constitutively active MEK was able to reverse the LfB17-34-enhanced pigmentation, melanin content, and tyrosinase activity, suggesting a role of Erk signaling in the process of LfB17‑34-mediated pigmentation. Taken together, these results suggest that LfB17‑34 induces melanogenesis in B16F10 cells primarily through increased tyrosinase expression and activity and that LfB17‑34 could be further developed for the treatment of hypopigmentation disorders.

Transferred nuclear Overhauser effect analyses of membrane-bound enkephalin analogues by sup 1 H nuclear magnetic resonance: Correlation between activities and membrane-bound conformations

Energy Technology Data Exchange (ETDEWEB)

Milon, Alain; Miyazawa, Tatsuo; Higashijima, Tsutomu (Univ. of Tokyo (Japan))

1990-01-09

Leu-enkephalin, (D-Ala{sup 2})Leu-enkephalin, and (D-Ala{sup 2})Leu-enkephalinamide (agonists) and (L-Ala{sup 2})Leu-enkephalin (inactive analogue) bind to lipid bilayer consisting of phosphatidylcholine and phosphatidylserine. The conformations that these compounds assume, once bound to perdeuterated phospholipid bilayer, have been shown to be unique, as shown by the transferred nuclear Overhauser effect (TRNOE) of {sup 1}H NMR spectroscopy. In addition, their location in the bilayer was analyzed by TRNOE in the presence of spin-labeled phospholipids. These analyses showed a clear relationship between the activity and the peptide-membrane interaction. The three active peptides, when bound to membranes, adopt the same conformation, characterized by a type II{prime} {beta}-turn around Gly{sup 3}-Phe and a {gamma}-turn around Gly{sup 2} (or D-Ala{sup 2}). The inactive analogue, (L-Ala{sup 2})Leu-enkephalin, displayed a completely different TRNOE pattern corresponding to a different conformation in the membrane-bound state. The tyrosine residue of the active compounds is not inserted into the interior of membrane, but it is inserted into the bilayer for the L-Ala{sup 2} analogue. According to these results, (L-Ala{sup 2})Leu-enkephalin may be explained to be inactive because the mode of binding to the membranes is different from that of active compounds.

Benchmarking of copper(II) LFMM parameters for studying amyloid-β peptides.

Science.gov (United States)

Mutter, Shaun T; Deeth, Robert J; Turner, Matthew; Platts, James A

2018-04-01

Ligand field molecular mechanics (LFMM) parameters have been benchmarked for copper (II) bound to the amyloid-β 1-16 peptide fragment. Several density functional theory (DFT) optimised small test models, representative of different possible copper coordination modes, have been used to test the accuracy of the LFMM copper bond lengths and angles, resulting in errors typically less than 0.1 Å and 5°. Ligand field molecular dynamics (LFMD) simulations have been carried out on the copper bound amyloid-β 1-16 peptide and snapshots extracted from the subsequent trajectory. Snapshots have been optimised using DFT and the semi-empirical PM7 method resulting in good agreement against the LFMM calculated geometry. Analysis of substructures within snapshots shows that the larger contribution of geometrical difference, as measured by RMSD, lies within the peptide backbone, arising from differences in DFT and AMBER, and the copper coordination sphere is reproduced well by LFMM. PM7 performs excellently against LFMM with an average RMSD of 0.2 Å over 21 tested snapshots. Further analysis of the LFMD trajectory shows that copper bond lengths and angles have only small deviations from average values, with the exception of a carbonyl moiety from the N-terminus, which can act as a weakly bound fifth ligand.

The common equine class I molecule Eqca-1*00101 (ELA-A3.1) is characterized by narrow peptide binding and T cell epitope repertoires.

Science.gov (United States)

Bergmann, Tobias; Moore, Carrie; Sidney, John; Miller, Donald; Tallmadge, Rebecca; Harman, Rebecca M; Oseroff, Carla; Wriston, Amanda; Shabanowitz, Jeffrey; Hunt, Donald F; Osterrieder, Nikolaus; Peters, Bjoern; Antczak, Douglas F; Sette, Alessandro

2015-11-01

Here we describe a detailed quantitative peptide-binding motif for the common equine leukocyte antigen (ELA) class I allele Eqca-1*00101, present in roughly 25 % of Thoroughbred horses. We determined a preliminary binding motif by sequencing endogenously bound ligands. Subsequently, a positional scanning combinatorial library (PSCL) was used to further characterize binding specificity and derive a quantitative motif involving aspartic acid in position 2 and hydrophobic residues at the C-terminus. Using this motif, we selected and tested 9- and 10-mer peptides derived from the equine herpesvirus type 1 (EHV-1) proteome for their capacity to bind Eqca-1*00101. PSCL predictions were very efficient, with an receiver operating characteristic (ROC) curve performance of 0.877, and 87 peptides derived from 40 different EHV-1 proteins were identified with affinities of 500 nM or higher. Quantitative analysis revealed that Eqca-1*00101 has a narrow peptide-binding repertoire, in comparison to those of most human, non-human primate, and mouse class I alleles. Peripheral blood mononuclear cells from six EHV-1-infected, or vaccinated but uninfected, Eqca-1*00101-positive horses were used in IFN-γ enzyme-linked immunospot (ELISPOT) assays. When we screened the 87 Eqca-1*00101-binding peptides for T cell reactivity, only one Eqca-1*00101 epitope, derived from the intermediate-early protein ICP4, was identified. Thus, despite its common occurrence in several horse breeds, Eqca-1*00101 is associated with a narrow binding repertoire and a similarly narrow T cell response to an important equine viral pathogen. Intriguingly, these features are shared with other human and macaque major histocompatibility complex (MHC) molecules with a similar specificity for D in position 2 or 3 in their main anchor motif.

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

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