Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.64 (proteinase K)
 4,071 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Spleen cells from mice immunized with a Bordetella pertussis N-lauroyl sarcosine membrane extract (SME) were used to generate hybridoma cells lines producing monoclonal antibodies (mAbs). Seven mAbs were shown to be specific to B. pertussis lipo-oligosaccharide (LOS) by immunoblotting of SME or purified LOS following SDS-PAGE. All mAbs reacted with the B. pertussis Tohama I strain of the LOS AB phenotype, and did not react with the atypical variant strain 134 of the LOS B phenotype. The immune reactivity of the mAbs was retained after treatment of SME with proteinase K and was lost after sodium periodate treatment. No cross-reactivity was observed with the mAbs when tested against B. parapertussis and other Gram-negative bacteria. However, all mAbs reacted with B. bronchiseptica. Binding assays with live B. pertussis cells demonstrated that mAbs strongly reacted with cell surface exposed antigenic determinants. High bacterial cell lytic capability was observed for five of these mAbs. Concentrations between 0.22 and 2.2 micrograms mAb ml-1 (0.1 and 1 microgram per 450 microliter assay) purified by protein A were required to kill at least 50% of the bacteria. Competition immunoassays with biotinylated antibodies showed that the bacteriolytic and non-bacteriolytic mAbs were directed to different epitopes of the B. pertussis LOS A.
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PMID:Characterization and comparative bactericidal activity of monoclonal antibodies to Bordetella pertussis lipo-oligosaccharide A. 171 58

The heterohybridoma cell line HBp2 secreting human monoclonal antibody (hMAb) directed against Bordetella pertussis was generated by fusing SP2/HPT heteromyeloma cells with human spleen lymphocytes, after in vitro stimulation for 6 days. The hybridoma was maintained in culture for more than 1 year with continuous antibody secretion. The hMAb HBp2, an IgM, reacted with untreated and proteinase K-treated B. pertussis outer membrane antigens, whereas the reactivity was lost when the antigen was treated with sodium periodate. Human MAb HBp2 was shown to be specific to B. pertussis LOS by immunoblotting of whole cell extracts after SDS-PAGE. In a dot enzyme immunoassay, HBp2 reacted with all B. pertussis strains and clinical isolates tested except for four atypical variant strains of the LOS B phenotype. Human MAb HBp2 also reacted with a clinical isolate of B. bronchiseptica. No reaction was observed against B. parapertussis and other gram-negative species. Together these studies suggested that HBp2 is reactive with carbohydrate epitopes present on the LOS A. Binding assays with live bacteria demonstrated that hMAb HBp2 reacted with cell surface exposed epitopes on B. pertussis but the antibody did not bind significantly to the surface on intact B. bronchiseptica cells. When examined for bactericidal activity in the presence of complement, hMAb HBp2 showed high lytic capability against B. pertussis while no killing was obtained against B. bronchiseptica. These experiments established that LOS A is a target for human bactericidal antibodies. This antigen merits further investigation as a potentially important component in human immunity to B. pertussis infection.
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PMID:Biological activity of a human monoclonal antibody to Bordetella pertussis lipooligosaccharide. 172 52

Bordetella pertussis Tohama phases I and III were grown to the late-exponential phase in liquid medium containing [3H]diaminopimelic acid and treated by a hot (96 degrees C) sodium dodecyl sulfate extraction procedure. Washed sodium dodecyl sulfate-insoluble residue from phases I and III consisted of complexes containing protein (ca. 40%) and peptidoglycan (60%). Subsequent treatment with proteinase K yielded purified peptidoglycan which contained N-acetylglucosamine, N-acetylmuramic acid, alanine, glutamic acid, and diaminopimelic acid in molar ratios of 1:1:2:1:1 and less than 2% protein. Radiochemical analyses indicated that 3H added in diaminopimelic acid was present in peptidoglycan-protein complexes and purified peptidoglycan as diaminopimelic acid exclusively and that pertussis peptidoglycan was not O acetylated, consistent with it being degraded completely by hen egg white lysozyme. Muramidase-derived disaccharide peptide monomers and peptide-cross-linked dimers and higher oligomers were isolated by molecular-sieve chromatography; from the distribution of these peptidoglycan fragments, the extent of peptide cross-linking of both phase I and III peptidoglycan was calculated to be ca. 48%. Unambiguous determination of the structure of muramidase-derived peptidoglycan fragments by fast atom bombardment-mass spectrometry and tandem mass spectrometry indicated that the pertussis peptidoglycan monomer fraction was surprisingly homogeneous, consisting of greater than 95% N-acetylglucosaminyl-N-acetylmuramyl-alanyl-glutamyl-diaminopimelyl++ +-alanine.
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PMID:Structure of Bordetella pertussis peptidoglycan. 288 47

Insertion sequence primers originally intended to amplify a singular specific product for the rapid diagnosis of Bordetella pertussis respiratory infection were used to differentiate strains of Pseudomonas (Burkholderia) cepacia. A modified sample preparation of proteinase K treatment and boiling was used in lieu of DNA extraction. The method was simple, rapid, and reproducible. This scheme identified 10 variations among 35 strains. Repeat strains from patients with cystic fibrosis and epidemiologically linked strains from an infection associated with a jet gun injection device were homologous in each setting.
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PMID:Insertional sequence primers for Bordetella pertussis diagnostic polymerase chain reaction differentiate strains of Pseudomonas cepacia. 754 Oct 63

Production of monoclonal antibodies (MAbs) to Bordetella avium surface proteins led to further characterization of the hemagglutinin. Proteins obtained by homogenization of whole-cell B. avium were used to immunize mice for the production of monoclonal antibodies. Immunoprecipitation and Western blot techniques were used to determine the specificity of three MAbs, which all recognized the B. avium 41-kilodalton (kd) surface protein. In addition, all of the MAbs inhibited hemagglutination (HA) of guinea pig erythrocytes by B. avium. The 41-kd protein recognized by the MAbs was observed by the indirect immunofluorescence test and sodium dodecyl sulfate-polyacrylamide gel electrophoresis to bind to guinea pig erythrocytes. When HA-positive isolates of B. avium were treated with periodic acid, which cleaves carbohydrates from proteins, the isolates became HA-negative. Likewise, treatment of HA-positive B. avium isolates with proteinase K, which would also remove carbohydrates associated with proteins on the surface of the bacterium, inhibited HA. Considering these data, we suggest that the B. avium hemagglutinin is a carbohydrate closely associated with the 41-kd surface protein.
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PMID:Production of monoclonal antibodies to the Bordetella avium 41-kilodalton surface protein and characterization of the hemagglutinin. 798 Feb 67

A major outbreak of 5,683 cases of pertussis occurred in northern Alberta, Canada, from December 1989 to January 1991. The outbreak highlighted a number of problems with current methods of pertussis diagnosis. In particular, an exceptionally high proportion of direct fluorescent-antibody (DFA)-positive, culture-negative specimens (88.4%) was identified. We took this opportunity to use polymerase chain reaction (PCR) methodology to examine whether the low culture rates were due to specimens containing dead organisms or whether the DFA results represented high numbers of false-positive results. A set of primer sequences within a Bordetella pertussis-specific repetitive element was used to amplify proteinase K extracts of B. pertussis DNA recovered from 279 submitted slides inoculated at the point of collection with nasopharyngeal material obtained from pernasal swabs. The PCR data corroborated the culture results: 84.6% of DFA-positive, culture-negative specimens were similarly PCR negative. At least three different bacterial species that were significantly cross-reactive with the commercial DFA reagent were identified in clinical specimens and in pure culture, providing one possible explanation for the false-positive DFA results. These results and other limitations of current diagnostic techniques underline the urgent need for a new DFA reagent with improved specificity and a standardized means of measuring the patient antibody response for the diagnosis of pertussis.
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PMID:Major outbreak of pertussis in northern Alberta, Canada: analysis of discrepant direct fluorescent-antibody and culture results by using polymerase chain reaction methodology. 834 47

The bacteriocin BacR1 was purified from culture supernatant of Staphylococcus aureus UT0007 by sequential ammonium sulfate precipitation, cation-exchange chromatography, and C4 reverse-phase chromatography steps. Mass spectrographic analysis indicated that the purified peptide has a molecular mass of 3,338 Da. It is resistant to environmental conditions, retaining full biological activity after exposure to pH extremes (pHs 3 to 11), heating at 95 degrees C for 15 min, and exposure to strong chaotropic agents. BacR1 was destroyed with a complete loss of biological activity after digestion with trypsin and proteinase K. Amino acid sequence analysis revealed a high concentration of Asx, Gly, and Pro residues and a high proportion of hydrophobic amino acids. The peptide is bactericidal and kills in a dose-dependent manner, but it does not lyse log-phase cells of Corynebacterium renale, the routine indicator organism for bacteriocin assay. A specific receptor for binding was detected on sensitive cells but not on insensitive cells. Competition assays showed that UV-inactivated cells could protect susceptible cells from antibacterial action. A partial inhibitory spectrum revealed that organisms from the following genera are susceptible: Staphylococcus, Streptococcus, Corynebacterium, Haemophilus, Bordetella, Moraxella, Pasteurella, Neisseria, and Bacillus.
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PMID:Purification and characterization of staphylococcin BacR1, a broad-spectrum bacteriocin. 936 2

We have evaluated the use of proteinase K (PK)-treated cells isolated from Helicobacter pylori as lipopolysaccharide (LPS) antigens in an immunoblot assay and an enzyme-linked immunosorbent assay (ELISA) for the serodiagnosis of H. pylori infection. The sera from patients with chronic gastritis, gastric ulcer, duodenal ulcer or gastric cancer, and from healthy adults with or without H. pylori infection were assayed with three commercial serodiagnostic kits (HM-CAP, Helico-G, and G.A.P. II) and novel methods relying on the use of PK-treated cells. The PK-treated cells used in these assays were selected on the basis of their possibility to possess a common epitope in the O-polysaccharides of H. pylori, which is known to be highly immunogenic in humans. Of the sera from these patients, 71-94% were positive with the commercial kits, 97% with immunoblot assay, and 90% with ELISA. On the other hand, of the healthy adults infected with H. pylori, 72-97% were positive with the commercial kits, 86% with immunoblot assay, and 72% with ELISA. PK-treated cells that did not contain the common epitope were unsuitable as an antigen for immunoblot assay or ELISA. Furthermore, the reactivity of these sera reacted specifically with H. pylori PK-treated cells but not with LPSs from other gram-negative bacteria, such as Campylobacter, Proteus, Bordetella, and Salmonella. These results demonstrate that the serological assays relying on the use of H. pylori PK-treated cells possessing a highly antigenic epitope are potentially useful as a serodiagnostic test for H. pylori infection.
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PMID:Utilization of proteinase K-treated cells as lipopolysaccharide antigens for the serodiagnosis of Helicobacter pylori infections. 971 4

Pertussis or whooping cough is an acute, highly contagious respiratory infection, which is particularly severe in infants under one year old. In classic disease, clinical diagnosis may present no difficulties. In other cases, it requires laboratory confirmation. Generally used methods are: culture, serology and PCR. For the latter, the sample of choice is a nasopharyngeal aspirate, and the simplest method for processing these samples uses proteinase K. Although results are generally satisfactory, difficulties often arise regarding the mucosal nature of the specimens. Moreover, uncertainties exist regarding the optimal conditions for sample storage. This study evaluated various technologies for processing and storing samples. Results enabled us to select a method for optimizing sample processing, with performance comparable to commercial methods and far lower costs. The experiments designed to assess the conservation of samples enabled us to obtain valuable information to guide the referral of samples from patient care centres to laboratories where such samples are processed by molecular methods.
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PMID:[Optimization of processing and storage of clinical samples to be used for the molecular diagnosis of pertussis]. 2058 31

Bordetella pertussis is the causative agent of pertussis, a highly contagious disease of the human respiratory tract. Despite very high vaccine coverage, pertussis has reemerged as a serious threat in the United States and many developing countries. Thus, it is important to pursue research to discover unknown pathogenic mechanisms of B. pertussis. We have investigated a previously uncharacterized locus in B. pertussis, the dra locus, which is homologous to the dlt operons of Gram-positive bacteria. The absence of the dra locus resulted in increased sensitivity to the killing action of antimicrobial peptides (AMPs) and human phagocytes. Compared to the wild-type cells, the mutant cells bound higher levels of cationic proteins and peptides, suggesting that dra contributes to AMP resistance by decreasing the electronegativity of the cell surface. The presence of dra led to the incorporation of d-alanine into an outer membrane component that is susceptible to proteinase K cleavage. We conclude that dra encodes a virulence-associated determinant and contributes to the immune resistance of B. pertussis. With these findings, we have identified a new mechanism of surface modification in B. pertussis which may also be relevant in other Gram-negative pathogens.
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PMID:D-alanine modification of a protease-susceptible outer membrane component by the Bordetella pertussis dra locus promotes resistance to antimicrobial peptides and polymorphonuclear leukocyte-mediated killing. 2401 34


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