scholarly journals Identification of an Immunodominant ABC Transporter in Methicillin-Resistant Staphylococcus aureusInfections

2000 ◽  
Vol 68 (6) ◽  
pp. 3200-3209 ◽  
Author(s):  
James P. Burnie ◽  
Ruth C. Matthews ◽  
Tracey Carter ◽  
Elaine Beaulieu ◽  
Michael Donohoe ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Abc Transporter ◽  
Potential Role ◽  
Recombinant Antibodies ◽  
Control Groups ◽  
Expression Library ◽  
Methicillin Resistant ◽  
Genomic Expression

ABSTRACT Immunoblotting sera from 26 patients with septicemia due to an epidemic strain of methicillin-resistant Staphylococcus aureus (EMRSA-15), 6 of whom died, revealed an immunodominant EMRSA-15 antigen at 61 kDa. There was a statistically significant correlate (P < 0.001) between survival and immunoglobulin G to the 61-kDa band. The antigen was identified by sequencing positive clones obtained by screening a genomic expression library of EMRSA-15 with pooled sera from patients taken after the septicemic episode. Eluted antibody reacted with the 61-kDa antigen on immunoblots. The amino terminus was obtained by searching the S. aureus NCTC 8325 and MRSA strain COL databases, and the whole protein was expressed in Escherichia coli TOP 10F′. The derived amino acid sequence showed homology with ABC transporters, with paired Walker A and Walker B motifs and 73% homology to YkpA fromBacillus subtilis. Epitope mapping of the derived amino acid sequence with sera from patients who had recovered from EMRSA-15 septicemia delineated seven epitopes. Three of these epitopes, represented by peptides 1 (KIKVYVGNYDFWYQS), 2 (TVIVVSHDRHFLYNNV), and 3 (TETFLRGFLGRMLFS), were synthesized and used to isolate human recombinant antibodies from a phage antibody display library. Recombinant antibodies against peptides 1 and 2 gave logarithmic reductions in organ colony counts, compared with control groups, in a mouse model of the infection. This study suggests the potential role of an ABC transporter as a target for immunotherapy.

scholarly journals Specificity of the HIV-1 Protease on Substrates Representing the Cleavage Site in the Proximal Zinc-Finger of HIV-1 Nucleocapsid Protein

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1092
Author(s):  
János András Mótyán ◽  
Márió Miczi ◽  
Stephen Oroszlan ◽  
József Tőzsér
Keyword(s):  
Amino Acid ◽  
Zinc Finger ◽  
Cleavage Site ◽  
Potential Role ◽  
Binding Mode ◽  
Interaction Energies ◽  
Vitro Assay ◽  
Hiv 1

To explore the sequence context-dependent nature of the human immunodeficiency virus type 1 (HIV-1) protease’s specificity and to provide a rationale for viral mutagenesis to study the potential role of the nucleocapsid (NC) processing in HIV-1 replication, synthetic oligopeptide substrates representing the wild-type and modified versions of the proximal cleavage site of HIV-1 NC were assayed as substrates of the HIV-1 protease (PR). The S1′ substrate binding site of HIV-1 PR was studied by an in vitro assay using KIVKCF↓NCGK decapeptides having amino acid substitutions of N17 residue of the cleavage site of the first zinc-finger domain, and in silico calculations were also performed to investigate amino acid preferences of S1′ site. Second site substitutions have also been designed to produce “revertant” substrates and convert a non-hydrolysable sequence (having glycine in place of N17) to a substrate. The specificity constants obtained for peptides containing non-charged P1′ substitutions correlated well with the residue volume, while the correlation with the calculated interaction energies showed the importance of hydrophobicity: interaction energies with polar residues were related to substantially lower specificity constants. Cleavable “revertants” showed one residue shift of cleavage position due to an alternative productive binding mode, and surprisingly, a double cleavage of a substrate was also observed. The results revealed the importance of alternative binding possibilities of substrates into the HIV-1 PR. The introduction of the “revertant” mutations into infectious virus clones may provide further insights into the potential role of NC processing in the early phase of the viral life-cycle.

scholarly journals Purification, characterization, gene sequence, and significance of a bacterioferritin from Mycobacterium leprae.

1994 ◽  
Vol 180 (1) ◽  
pp. 319-327 ◽  
Author(s):  
M C Pessolani ◽  
D R Smith ◽  
B Rivoire ◽  
J McCormick ◽  
S A Hefta ◽  
...  
Keyword(s):  
Amino Acid ◽  
Membrane Protein ◽  
Amino Acid Sequence ◽  
Mycobacterium Leprae ◽  
Native Molecular Mass ◽  
Molecular Features ◽  
Ferroxidase Center ◽  
Considerable Homology

The study of tissue-derived Mycobacterium leprae provides insights to the immunopathology of leprosy and helps identify broad molecular features necessary for mycobacterial parasitism. A major membrane protein (MMP-II) of in vivo-derived M. leprae previously recognized (Hunter, S.W., B. Rivoire, V. Mehra, B.R. Bloom, and P.J. Brennan. 1990. J. Biol. Chem. 265:14065) was purified from extracts of the organism and partial amino acid sequence obtained. This information allowed recognition, within one of the cosmids that encompass the entire M. leprae genome, of a complete gene, bfr, encoding a protein of subunit size 18.2 kD. The amino acid sequence deduced from the major membrane protein II (MMP-II) gene revealed considerable homology to several bacterioferritins. Analysis of the native protein demonstrated the iron content, absorption spectrum, and large native molecular mass (380 kD) of several known bacterioferritins. The ferroxidase-center residues typical of ferritins were conserved in the M. leprae product. Oligonucleotides derived from the amino acid sequence of M. leprae bacterioferritin enabled amplification of much of the MMP-II gene and the detection of homologous sequences in Mycobacterium paratuberculosis, Mycobacterium avium, Mycobacterium tuberculosis, Mycobacterium intracellulare, and Mycobacterium scrofulaceum. The role of this iron-rich protein in the virulence of M. leprae is discussed.

scholarly journals Structural features of the low-molecular-mass human salivary mucin

1992 ◽  
Vol 287 (2) ◽  
pp. 639-643 ◽  
Author(s):  
M S Reddy ◽  
L A Bobek ◽  
G G Haraszthy ◽  
A R Biesbrock ◽  
M J Levine
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Molecular Mass ◽  
Gel Filtration ◽  
Structural Features ◽  
Cdna Expression Library ◽  
Cdna Clones ◽  
Expression Library ◽  
Mrna Species ◽  
Salivary Mucin

The low-molecular-mass human salivary mucin has at least two isoforms, MG2a and MG2b, that differ primarily in their sialic acid and fucose content. In this study, we characterize further these isoforms, particularly their peptide moieties. Trypsin digests of MG2a and MG2b yielded high- and low-molecular-mass glycopeptides following gel filtration on Sephacryl S-300. The larger glycopeptides from MG2a and MG2b had similar amino acid compositions and identical N-terminal sequences, suggesting common structural features between their peptides. An oligonucleotide probe generated from the amino acid sequence of the smaller glycopeptide from MG2a was employed in Northern-blot analysis. This probe specifically hybridized to two mRNA species from human submandibular and sublingual glands. A cDNA clone selected from a human submandibular gland cDNA expression library with antibody generated against deglycosylated MG2a also hybridized to these two mRNA species. In both cases, the larger mRNA was polydisperse, and the hybridization signal was more intense in the sublingual gland. In addition, the N-terminal amino acid sequence of the larger glycopeptide was found to be part of one of the selected MG2 cDNA clones.

An outbreak of methicillin resistant Staphylococcus aureus on a burn unit: potential role of contaminated hydrotherapy equipment

Burns ◽  
2001 ◽  
Vol 27 (7) ◽  
pp. 681-688 ◽  
Author(s):  
John M. Embil ◽  
Judy A. McLeod ◽  
Ali M. Al-Barrak ◽  
Genevieve M. Thompson ◽  
Fred Y. Aoki ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Potential Role ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Methicillin Resistant ◽  
Burn Unit

scholarly journals Spontaneous bacterial peritonitis due to methicillin-resistant Staphylococcus aureus in a patient with cirrhosis: the potential role for daptomycin and review of the literature

2015 ◽  
Vol 7 (3) ◽  
Author(s):  
Marco Falcone ◽  
Alessandro Russo ◽  
Giovanni Pacini ◽  
Manuela Merli ◽  
Mario Venditti
Keyword(s):  
Spontaneous Bacterial Peritonitis ◽  
Potential Role ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Healthcare Associated Infections ◽  
Review Of The Literature ◽  
Methicillin Resistant ◽  
Bacterial Peritonitis ◽  
Healthcare Associated ◽  
Gram Positive Cocci

Gram-positive cocci are emerging causes of spontaneous bacterial peritonitis (SBP), especially in patients with healthcare-associated infections. We report the case of a 68-year-old man with hepatitis C virus and alcohol-related cirrhosis who developed SBP due to methicillin-resistant <em>Staphylococcus</em> <em>aureus</em> treated with daptomycin. We discuss the potential role of daptomycin in this setting with a review of the literature about the use of daptomycin in primary or secondary bacterial peritonitis.

scholarly journals The Potential Role of 6-gingerol and 6-shogaol as ACE Inhibitors in Silico Study

2020 ◽  
Vol 8 (2) ◽  
pp. 210
Author(s):  
Yohanes Bare ◽  
Maria Helvina ◽  
Gabriella Chandrakirana Krisnamurti ◽  
Mansur S
Keyword(s):  
Amino Acid ◽  
Angiotensin Converting Enzyme ◽  
Binding Site ◽  
Potential Role ◽  
Enzyme Inhibitor ◽  
Renin Angiotensin System ◽  
Data Bank ◽  
Amino Acid Residues ◽  
Converting Enzyme

Hypertension has become the third highest cause of death in Indonesia. The condition is correlated with angiotensin-converting enzyme (ACE), and possibly managed with the use of drugs. In addition, some natural compounds, including 6-shogaol and 6-gingerol from ginger, are used to decrease blood pressure. However, the mechanism and binding site of these compounds to ACE protein is currently unclear. This study, therefore, aims to investigate the potential role of these compounds as an angiotensin-converting enzyme inhibitor. The ACE protein was downloaded from Protein Data Bank (PDB) database with the ID: 3bkk, while the 6-shogaol (CID: 5281794) and 6-gingerol (CID: 44559528) ligands were obtained from the PubChem database. Meanwhile, molecular docking was established using HEX 8.0.0 software. The analysis examined the amino acid residues and the bonds formed from these interactions. According to the results, fourteen amino acid residues were formed by the interaction between 6-shogaol and ACE, while the interaction between 6-gingerol and ACE formed eight amino acids. Also, thirteen amino acid residues in the novelty binding site of ACE were discovered to be blocked by the ligands from ginger. Therefore, the compounds have potential roles as inhibitors, and this possibly helps to prevent regulation of the renin-angiotensin system. These interactions also formed hydrogen bonds, as well as electrostatic, unfavorable, and hydrophobic sites, making the binding stronger than others. 

scholarly journals Human myeloperoxidase gene: molecular cloning and expression in leukemic cells

Blood ◽  
1986 ◽  
Vol 68 (6) ◽  
pp. 1411-1414
Author(s):  
KS Chang ◽  
JM Trujillo ◽  
RG Cook ◽  
SA Stass
Keyword(s):  
Gene Expression ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Cdna Clone ◽  
Northern Blot ◽  
Single Gene ◽  
Myelogenous Leukemia ◽  
Cloning And Expression ◽  
Leukemic Cells ◽  
Expression Library

We have molecularly cloned the human myeloperoxidase (MPO) gene from the lambda gt11 expression library by screening with an affinity- purified MPO antibody. The cDNA clone of the MPO gene was used to study MPO gene expression in leukemic cells. The amino acid sequence predicted from the nucleotide sequence of the cDNA clone pMP401 matched exactly the 23 amino acid sequence of the NH2-terminal of the 60,000 MPO subunit. We found that MPO cDNA hybridized to a single EcoRI genomic band of 19 kb, indicating that the MPO gene represents a single gene in the human genome. Northern blot analysis of RNA isolated from leukemic cell lines and acute myelogenous leukemia (AML) patients' samples shows that MPO gene expression correlated with myeloid lineage. The intensity of MPO mRNA expression on Northern blot correlated with the level of MPO expression by cytochemical staining. Multiple species of MPO mRNA were found. This indicates that a single MPO gene may encode different RNA species through a mechanism of posttranscriptional processing or that multiple transcriptional start/termination sites exist in the MPO gene.

scholarly journals Prevalence and Genetic Diversity of Staphylococcal Enterotoxin (-Like) Genes sey, selw, selx, selz, sel26 and sel27 in Community-Acquired Methicillin-Resistant Staphylococcus aureus

Toxins ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 347 ◽  
Author(s):  
Meiji Soe Aung ◽  
Noriko Urushibara ◽  
Mitsuyo Kawaguchiya ◽  
Masahiko Ito ◽  
Satoshi Habadera ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Staphylococcus Aureus ◽  
Virulence Factors ◽  
Potential Role ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Methicillin Resistant ◽  
Sequence Identity ◽  
Genetic Groups ◽  
Epidemiological Features

Staphylococcal enterotoxins (SEs) are virulence factors of Staphylococcus aureus associated with various toxic diseases due to their emetic and superantigenic activities. Although at least 27 SE(-like) genes have been identified in S. aureus to date, the newly identified SE(-like) genes have not yet been well characterized by their epidemiological features. In this study, the prevalence and genetic diversity of SE gene sey and SE-like genes selw, selx, selz, sel26, and sel27 were investigated for 624 clinical isolates of community-acquired methicillin-resistant S. aureus (CA-MRSA). The most prevalent SE(-like) gene was selw (92.9%), followed by selx (85.6%), sey (35.4%) and selz (5.6%), while sel26 and sel27 were not detected. Phylogenetically, sey, selw, selx, and selz were discriminated into 7, 10, 16, and 9 subtypes (groups), respectively. Among these subtypes, sey was the most conserved and showed the highest sequence identity (>98.8%), followed by selz and selx. The SE-like gene selw was the most divergent, and four out of ten genetic groups contained pseudogenes that may encode truncated product. Individual subtypes of SE(-like) genes were generally found in isolates with specific genotypes/lineages of S. aureus. This study revealed the putative ubiquity of selw and selx and the prevalence of sey and selz in some specific lineages (e.g., ST121) in CA-MRSA, suggesting a potential role of these newly described SEs(-like) in pathogenicity.

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