Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0348321 (Haemophilus)
 15,372 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mutants of Actinobacillus pleuropneumoniae strain HK 361 (serotype 2) were isolated which were deficient in type II (Ca2(+)-dependent) haemolysin activity (Hly-). Some of the Hly- mutants secreted a potent, heat-labile extracellular cytotoxic activity against porcine alveolar macrophages. Comparison of cell-free culture supernatant from the parent strain and some Hly- mutants by SDS-PAGE and immunoblotting revealed the loss of a major extracellular polypeptide of 109 kDa. Two Hly- mutants which in addition failed to secrete a 120 kDa polypeptide produced no extracellular cytotoxic activity, suggesting that the 120 kDa protein was the cytotoxin. Antiserum raised to the culture supernatant from a Hly- mutant lacking the 109 kDa polypeptide recognized the 120 kDa band, but not the 109 kDa band, in immunoblots and neutralized the cytotoxic activity, but not the haemolytic activity, of A. pleuropneumoniae. The 120 kDa polypeptide and extracellular cytotoxic activity were widespread among A. pleuropneumoniae strains, but absent from related bacterial pathogens of the pig: Actinobacillus suis, Haemophilus parasuis and Pasteurella multocida. A clear correlation was found between the presence of the 120 kDa polypeptide and cytotoxic activity in culture supernatants. The cytotoxic activity of all the strains tested was neutralized by antibody to the Hly- extracellular material and by convalescent pig serum. It is proposed that the 120 kDa polypeptide represents the cytotoxin of A. pleuropneumoniae, that it is distinct from the haemolysin, and that it be termed pleurotoxin.
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PMID:The cytotoxin of Actinobacillus pleuropneumoniae (pleurotoxin) is distinct from the haemolysin and is associated with a 120 kDa polypeptide. 203 78

The nucleotide sequence of the ROB-1 beta-lactamase gene from Haemophilus influenzae plasmid RRob was determined. The structural gene encodes a polypeptide of 305 amino acids, with an estimated molecular mass of 30,424 for the mature form of the protein. The ROB-1 gene showed low homologies with other beta-lactamases at the nucleic acid level. By using two statistical computer methods, assessment of the extent of similarity between ROB-1 and other known beta-lactamase amino acid sequences suggested that ROB-1 is a class A enzyme. Alignment of class A beta-lactamases with ROB-1 identified conserved residues. The use of a mutation matrix for detecting distance relationships indicated that ROB-1 has higher values and homologies with beta-lactamases of gram-positive bacteria, giving insight into its ancestry and divergence.
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PMID:Sequence analysis and evolutionary perspectives of ROB-1 beta-lactamase. 220 Dec 53

Protein D, a novel surface protein of the bacterial species Haemophilus influenzae with affinity for human IgD, was isolated after solubilization with sonication and Sarcosyl-extraction by a single SDS-PAGE step. From 1 ml of packed bacteria was prepared 0.25 mg of purified protein D. The apparent m.w. of protein D was estimated to 42,000 by SDS-PAGE and gel chromatography. Edman degradation cycles of protein D produced no amino acid phenylthiohydantoin derivatives and the amino-terminal end of the single protein D polypeptide chain is thus probably blocked. Protein D differs from all previously described outer membrane proteins (protein 1 to 6) of H. influenzae. Thus, protein D did not react with antibodies against protein 1 or protein 2 and the latter proteins did not bind IgD. Protein D was found to exhibit unique Ig-binding properties. Thus, in dot blots protein D bound four different human IgD myeloma proteins but not IgG, IgM, IgA, IgE, or some additional proteins. On the IgD molecule, constant parts of the H chains both in the Fab and Fc fragments appear responsible for the interaction with protein D. This novel Ig-binding reagent promises to be of theoretical and practical interest in immunologic and microbiologic research.
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PMID:Protein D of Haemophilus influenzae. A novel bacterial surface protein with affinity for human IgD. 223 Jan 24

Porphyrin ring source appears to alter the outer membrane protein (OMP) profile of some, but not all, non-typable (NT) Haemophilus influenzae strains isolated from sputum. When haemin was replaced with protoporphyrin IX, 41% of strains examined produced increased amounts of a polypeptide of 84 Kda and new OMPs of either 120 or 150 Kda. Immunoblotting with paired patient's sera revealed that antibodies reactive with these proteins were present, demonstrating OMP antigenicity and expression in vivo and indicating that these isolates of NT H. influenzae may display an altered OMP phenotype when growing in the human lung.
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PMID:Porphyrin ring source can alter the outer membrane protein profile of non-typable Haemophilus influenzae. 231 82

Outer membranes from Haemophilus pleuropneumoniae grown under iron-replete and iron-restricted conditions in vitro were analysed by means of SDS-PAGE and immunoblotting. Iron restriction resulted in the appearance of two or more novel polypeptides in the molecular size range of 96-102 kD and an increased amount of a 79 kD polypeptide. These polypeptides were recognized by porcine immune sera indicating their production by H. pleuropneumoniae during growth in vivo. Although soluble siderophore production could not be detected, growth of the organisms on an iron-restricted medium was enhanced by the presence of porcine transferrin but not by bovine or human transferrin. The results suggest that H. pleuropneumoniae possesses a specific transferrin receptor, perhaps in the form of an iron-regulated outer membrane protein.
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PMID:Responses of Haemophilus pleuropneumoniae to iron restriction: changes in the outer membrane protein profile and the removal of iron from porcine transferrin. 253 2

The nucleotide sequence of the leftmost 2,363 base pairs of the HP1 genome, which includes the attachment site (attP) and the integration region, was determined. This sequence contained an open reading frame encoding a 337-residue polypeptide, which is a member of the integrase family of site-specific recombination proteins as judged by sequence comparison. The open reading frame was located immediately adjacent to the att site and was oriented so that initiation of translation would begin distal to the att site and end in its immediate vicinity. Expression of this DNA segment in Escherichia coli provided extracts which promoted site-specific recombination between plasmids containing cloned HP1 attP and Haemophilus influenzae attB sites. This recombination was directional, since no reaction was observed between plasmids containing attR and attL sites. The reaction was stimulated by the accessory protein integration host factor of E. coli. Evidence was also obtained that the integration host factor influenced the levels of HP1 integrase expression. The deduced amino acid sequence of HP1 integrase has remarkable similarity to that deduced for the integrase of coliphage 186.
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PMID:Nucleotide sequence and expression of the gene for the site-specific integration protein from bacteriophage HP1 of Haemophilus influenzae. 254 15

One hundred and nine strains of Haemophilus influenzae type b were subtyped by sodium dodecyl sulphate polyacrylamide gel electrophoresis of whole-cell polypeptides. Twenty-one strains from England, 44 from Scotland, 8 from Sweden, 6 from the Netherlands and 30 from the USA were examined. Some of these strains had been subtyped by outer membrane protein analysis; most of the strains had been isolated from cases of invasive disease. Comparison of polypeptide profiles using the Dice coefficient of similarity showed that the majority of European strains were closely related and formed a single large group. Four smaller groups were identified; three of these included American and European strains, indicating a world-wide distribution of subtypes. However, the common European and American subtypes fell into different groups, indicating the existence of marked geographical variations in subtype frequency.
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PMID:Subtyping of Haemophilus influenzae type b strains from Europe and North America by SDS-PAGE of whole-cell polypeptides: the geographical distribution of subtypes. 278 12

Two Haemophilus influenzae Rd genes each complemented the pleiotropic defects of the recA-like mutation rec-1. One gene, fec, was isolated on a 3.6-kilobase-pair EcoRI restriction fragment by complementation of the Fec- phenotype of bacteriophage lambda. The other gene, rec, was identified on a 3.1-kilobase-pair EcoRI fragment by Southern hybridization by using recA-like gene probes from Erwinia carotovora and Pseudomonas aeruginosa PAO. In a rec-1 strain of H. influenzae, the cloned genes restored resistance to UV irradiation, transformation by chromosomal DNA, and spontaneous release of HP1 prophage to wild-type levels. The fec and rec genes were located on the cloned segments by insertion and deletion mutagenesis and subcloning. The restriction endonuclease cleavage maps of the two DNAs were similar but not identical. Southern hybridization demonstrated that the two EcoRI restriction fragments contained homologous DNA sequences, but a fec gene-specific probe was prepared. Each gene encoded a 38,000-dalton polypeptide.
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PMID:Two Haemophilus influenzae Rd genes that complement the recA-like mutation rec-1. 278 4

P6, a 16,600-dalton protein present in the outer membranes of both typeable and nontypeable strains, may be an important antigen in immunity to Haemophilus influenzae. The gene encoding P6 of a nontypeable strain of H. influenzae was cloned by using bacteriophage lambda gt11. Four recombinant phages were detected by screening plaques with monoclonal antibodies and a polyclonal antiserum. One recombinant phage, clone O, produced a full-length gene product which was expressed at a high yield. The DNA insert contained within this phage was cloned into the plasmid vector pUC18 to create the recombinant plasmid pBUD1. An Escherichia coli transformant containing this plasmid produced a protein which had an apparent molecular weight identical to that of H. influenzae P6, as determined by Western blot (immunoblot) analyses. Expression of the P6 polypeptide by both clone 0 and the transformant was independent of induction of the lac operon by isopropyl-beta-D-thiogalactopyranoside, suggesting that transcription was from the promoter of the P6 gene. Immunoelectron microscopy using a monoclonal antibody with specificity for a P6 surface epitope detected the presence of P6 on the surface of the transformant. The insert in pBUD1 was cut down in size to approximately 800 base pairs. The resultant plasmid, pBUD5, also coded for a full-length gene product. DNA sequence analysis revealed that the P6 gene contains transcriptional and translational sequences resembling those recognized in E. coli and a signal sequence characteristic of procaryotic membrane proteins. In addition, the carboxy terminus of this signal sequence shares homology with a common sequence found in bacterial lipoproteins, suggesting that P6 is a lipoprotein. Posttranslational proteolytic cleavage of the signal sequence would result in a protein composed of 134 amino acids.
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PMID:Cloning and sequencing of Haemophilus influenzae outer membrane protein P6. 325

Penicillin-binding proteins (PBPs) from Haemophilus influenzae RD purified by a combination of affinity chromatography, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and electroelution were used to immunize rabbits to obtain specific antisera. Antisera directed against PBP 1 (1b) of H. influenzae cross-reacted with representative organisms of the family Pasteurellaceae and with many members of the family Enterobacteriaceae but not with other gram-negative organisms. Immunization with purified PBP 3 of H. influenzae produced antisera that reacted with PBP 1 (1b) of H. influenzae and showed the same cross-reactive pattern with other species as the anti-PBP 1 antiserum. A 24,000-molecular-weight polypeptide of H. influenzae, not radiolabeled by [35S]penicillin, reacted with antisera against purified PBPs 1 (1a, 1b), 2, and 3. The results suggest that antigenic epitopes are shared among similar PBPs from related species and even among different PBPs within the same species.
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PMID:Antigenic relationships among penicillin-binding proteins 1 from members of the families Pasteurellaceae and Enterobacteriaceae. 349 81


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