Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1175175 (SARS)
 19,188 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The 3C-like protease (3CLpro) of severe acute respiratory syndrome (SARS) has been proposed as an attractive target for drug design. His41 and Cys145 were essential for the active site as the principal catalytic residues. In this study, we mutated the two sites, expressed four resulting mutants in Escherichia coli and characterized. All mutants showed undetectable activity in trans-cleavage assay. In addition, we introduced a 31-mer peptide containing an auto-cleavage site to the N-terminal of the proteases and found the peptide could be cleaved efficiently by 3CLsc itself, but, among the four mutants, only the mutant Cys145-->Ser showed residual activity as detected by the auto-cleavage assay. The data supported the proposition unequivocally that SARS-CoV 3CLpro was a member of serine proteases involving His41 and Cys145 residues at the active site. The auto-cleavage assay also provided a sensitive and reliable compensation to the traditional trans-cleavage assay.
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PMID:A novel auto-cleavage assay for studying mutational effects on the active site of severe acute respiratory syndrome coronavirus 3C-like protease. 1547 66

We have identified the membrane-active regions of the severe acute respiratory syndrome coronavirus (SARS CoV) spike glycoprotein by determining the effect on model membrane integrity of a 16/18-mer SARS CoV spike glycoprotein peptide library. By monitoring the effect of this peptide library on membrane leakage in model membranes, we have identified three regions on the SARS CoV spike glycoprotein with membrane-interacting capabilities: region 1, located immediately upstream of heptad repeat 1 (HR1) and suggested to be the fusion peptide; region 2, located between HR1 and HR2, which would be analogous to the loop domain of human immunodeficiency virus type 1; and region 3, which would correspond to the pretransmembrane region. The identification of these membrane-active regions, which are capable of modifying the biophysical properties of phospholipid membranes, supports their direct role in SARS CoV-mediated membrane fusion, as well as facilitating the future development of SARS CoV entry inhibitors.
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PMID:Identification of the membrane-active regions of the severe acute respiratory syndrome coronavirus spike membrane glycoprotein using a 16/18-mer peptide scan: implications for the viral fusion mechanism. 1565 Jan 99

A hybridisation-based genosensor was designed on a 100 nm sputtered gold film. This material worked as an immobilisation and transduction surface. A 30-mer sequence that encodes a short lysine-rich region, unique to SARS (severe acute respiratory syndrome) virus, was chosen as target. A complementary strand (probe), labelled with a thiol group at the 3'-end, was immobilised on the film. After blocking the surface, hybridisation with the biotin-conjugated SARS strand (at the 3'-end) took place. Interaction with alkaline phosphatase-labelled streptavidin permits amplified indirect electrochemical detection. The analytical signal is constituted by an electrochemical process of indigo carmine, the soluble product of the enzymatic hydrolysis of 3-indoxyl phosphate. The use of a sensitive electrochemical technique such as square wave voltammetry allowed a detection limit of 6 pM to be obtained for this DNA sequence, lower than any other found in the bibliography. The parameters affecting the methodology were studied, with special attention being placed on selectivity. Specificity was clearly enhanced when interaction time and stringency (in the form of formamide percentage) were increased. With 1h of strand interaction and employing 50% of formamide in the hybridisation buffer, a 3-base mismatch strand was perfectly distinguished from the complementary.
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PMID:Genosensor on gold films with enzymatic electrochemical detection of a SARS virus sequence. 1579 23

We studied the adjuvanticity of recombinant Onchocerca volvulus activation associated protein-1 (rOv-ASP-1) for ovalbumin (OVA) in mice. After a single immunization and one boost, rOv-ASP-1 exceeded the efficacy of alum or MPL + TDM adjuvants in terms of end-point total IgG or IgG1 and IgG2a anti-OVA titres. Using the helminth-derived adjuvant, IgG isotype responses to OVA were of a mixed Th1/Th2 profile and spleen cell cytokines exclusively Th1-type. The potent adjuvanticity of rOv-ASP-1 was confirmed in mice vaccinated with a 37-mer peptide from the S protein of SARS-CoV and an HIV-1 gp120-CD4 chimeric polypeptide antigen. Unusually for a helminth product, the rOv-ASP-1 adjuvant augmented not only Th2 but also Th1 responses, the latter property being of potential utility in stimulating anti-viral immune responses.
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PMID:rOv-ASP-1, a recombinant secreted protein of the helminth Onchocercavolvulus, is a potent adjuvant for inducing antibodies to ovalbumin, HIV-1 polypeptide and SARS-CoV peptide antigens. 1583 68

A novel severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV) has been identified as the aetiological agent of SARS. We previously isolated and characterized SARS-CoV and SARS-CoV-like viruses from human and animals, respectively, suggesting that SARS could be transmitted from wild/farmed animals to humans. Comparison of the viral genomes indicated that sequence variation between animal and human isolates existed mainly in the spike (S) gene. We hypothesized that these variations may underlie a change of binding specificity of the S protein to the host cells, permitting viral transmission from animals to humans. Here we report that four 20-mer synthetic peptides (S protein fragments), designed to span these sequence variation hotspots, exhibited significant antiviral activities in a cell line. SARS-CoV infectivity was reduced over 10 000-fold through pre-incubation with two of these peptides, while it was completely inhibited in the presence of three peptides. Molecular modelling of the SARS-CoV peplomer suggests that three of these antiviral peptides map to the interfaces between the three monomers of the trimeric peplomer rather than the heptad repeat region from which short peptides are known to inhibit viral entry. Our results revealed novel regions in the spike protein that can be targeted to inhibit viral infection. The peptides identified in this study could be further developed into antiviral drugs.
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PMID:Synthetic peptides outside the spike protein heptad repeat regions as potent inhibitors of SARS-associated coronavirus. 1591 30

A 10-mer overlapping peptide library has been synthesized for screening and identification of linear B-cell epitopes of severe acute respiratory syndrome associated coronavirus (SARS-CoV), which spanned the major structural proteins of SARS-CoV. One hundred and eleven candidate peptides were positive according to the result of PEPscan, which were assembled into 22 longer peptides. Five of these peptides showed high cross-immunoreactivities (approximately 66.7 to 90.5%) to SARS convalescent patients' sera from the severest epidemic regions of the China mainland. Most interestingly, S(471-503), a peptide located at the receptor binding domain (RBD) of SARS-CoV, could specifically block the binding between the RBD and angiotensin-converting enzyme 2, resulting in the inhibition of SARS-CoV entrance into host cells in vitro. The study demonstrated that S(471-503) peptide was a potential immunoantigen for the development of peptide-based vaccine or a candidate for further drug evaluation against the SARS-CoV virus-cell fusion.
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PMID:Screening and identification of linear B-cell epitopes and entry-blocking peptide of severe acute respiratory syndrome (SARS)-associated coronavirus using synthetic overlapping peptide library. 1615 58

We applied artificial neural networks (ANN) for the prediction of targets of immune responses that are useful for study of vaccine formulations against viral infections. Using a novel data representation, we developed a system termed MULTIPRED that can predict peptide binding to multiple related human leukocyte antigens (HLA). This implementation showed high accuracy in the prediction of the promiscuous peptides that bind to five HLA-A2 allelic variants. MULTIPRED is useful for the identification of peptides that bind multiple HLA-A2 variants as a group. By implementing ANN as a classification engine, we enabled both the prediction of peptides binding to multiple individual HLA-A2 molecules and the prediction of promiscuous binders using a single model. The ANN MULTIPRED predicts peptide binding to HLA-A*0205 with excellent accuracy (area under the receiver operating characteristic curve--AROC>0.90), and to HLA-A*0201, HLA-A*0204 and HLA-A*0206 with high accuracy (AROC>0.85). Antigenic regions with high density of binders ("antigenic hot-spots") represent best targets for vaccine design. MULTIPRED not only predicts individual 9-mer binders but also predicts antigenic hot spots. Two HLA-A2 hot-spots in Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) membrane protein were predicted by using MULTIPRED.
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PMID:Neural models for predicting viral vaccine targets. 1627 55

Rapid elucidation of neutralizing antibody epitopes on emerging viral pathogens like severe acute respiratory syndrome (SARS) coronavirus (CoV) or highly pathogenic avian influenza H5N1 virus is of great importance for rational design of vaccines against these viruses. Here we combined screening of phage display random peptide libraries with a unique computer algorithm "Mapitope" to identify the discontinuous epitope of 80R, a potent neutralizing human anti-SARS monoclonal antibody against the spike protein. Using two different types of random peptide libraries which display cysteine-constrained loops or linear 13-15-mer peptides, independent panels containing 42 and 18 peptides were isolated, respectively. These peptides, which had no apparent homologous motif within or between the peptide pools and spike protein, were deconvoluted into amino acid pairs (AAPs) by Mapitope and the statistically significant pairs (SSPs) were defined. Mapitope analysis of the peptides was first performed on a theoretical model of the spike and later on the genuine crystal structure. Three clusters (A, B and C) were predicted on both structures with remarkable overlap. Cluster A ranked the highest in the algorithm in both models and coincided well with the sites of spike protein that are in contact with the receptor, consistent with the observation that 80R functions as a potent entry inhibitor. This study demonstrates that by using this novel strategy one can rapidly predict and identify a neutralizing antibody epitope, even in the absence of the crystal structure of its target protein.
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PMID:Mapping a neutralizing epitope on the SARS coronavirus spike protein: computational prediction based on affinity-selected peptides. 1663 Jun 34

In this work, a gold complex is used as electroactive label for monitoring hybridization assays on glassy carbon electrodes. Ionic gold is bound to a 30-mer sequence of the SARS (severe acute respiratory syndrome) virus, responsible for the atypical pneumonia, using sodium aurothiomalate. In order to label this single strand, a mixture of sodium aurothiomalate and the strand is prepared. Then, it is incubated for 24 h at 37 degrees C and, finally, free gold is separated from the labeled strand by a dialysis against a 0.15M NaCl solution (pH 7.5). The DNA hybridization sensor is designed immobilizing the complementary probe on the pre-treated electrode surface and, then, the hybridization reaction takes place with the gold labeled strand. The electrochemical determination is based on the catalytic effect of electrodeposited gold on the reduction of silver ions. In non-stringent experimental conditions, a limit of detection of 15 fmol (30 microL) is obtained, and discrimination between a complementary oligonucleotide and a three-based mismatch complementary oligonucleotide is achieved. For the discrimination of a single-base mismatch, is needed to use stringent conditions (50% of formamide in the hybridization buffer).
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PMID:DNA hybridization sensor based on aurothiomalate electroactive label on glassy carbon electrodes. 1676 39

Peptides derived from the membrane proximal region of fusion proteins of human immunodeficiency viruses 1 and 2, Coronavirus 229 E, severe acute respiratory syndrome coronavirus and Ebola virus were all potent antagonists of the formyl peptide receptor expressed in Chinese hamster ovary cells. Binding of viral peptides was affected by the naturally occurring polymorphisms at residues 190 and 192, which are located at second extracellular loop-transmembrane helix 5 interface. Substitution of R190 with W190 enhanced the affinity for a severe acute respiratory syndrome coronavirus peptide 6 fold but reduced the affinity for N-formyl-Nle-Leu-Phe by 2.5 fold. A 12 mer peptide derived from coronavirus 229E (ETYIKPWWVWL) was the most potent antagonist of the formyl peptide receptor W190 with a K(i) of 230 nM. Fluorescently labeled ETYIKPWWVWL was effectively internalized by all three variants with EC(50) of approximately 25 nM. An HKU-1 coronavirus peptide, MYVKWPWYVWL, was a potent antagonist but N-formyl-MYVKWPWYVWL was a potent agonist. ETYIKPWWVWL did not stimulate GTPgammaS binding but inhibited the stimulation by formyl-NleLeuPhe. It also blocked beta arrestin translocation and receptor downregulation induced by formyl-Nle-Leu-Phe. This indicates that formyl peptide receptor may be important in viral infections and that variations in its sequence among individuals may affect their likelihood of viral and bacterial infections.
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PMID:Peptides derived from HIV-1, HIV-2, Ebola virus, SARS coronavirus and coronavirus 229E exhibit high affinity binding to the formyl peptide receptor. 1684 82


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