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)

A new restriction endonuclease has been isolated from Bacillus sphaericus R. The purification procedure includes Bio-Gel filtration, (NH4)2SO4 fractionation and phosphocellulose chromatography. After the phosphocellulose step the enzyme preparation is free of non-specific nucleases. Bsp cleaves double-stranded DNA with the same specificity as Bacillus subtilis (Bsu) and Haemophilus aegyptius (HaeIII) restriction endonucleases, as concluded from digests and double-digests of phiX174 replicative form DNA with Bsu and Bsp. The 5'-terminal nucleotide of the cleavage products was shown to be C. Bacillus sphaericus R produces Bsp in extremely large quantities and the enzyme can be easily purified in high yield.
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PMID:A new sequence-specific endonuclease (Bsp) from Bacillus sphaericus. 59 Jul 42

Mitochondrial DNA from several mammalian species has been digested with a site-specific restriction endonuclease (HaeIII) from Haemophilus aegyptius. A quantitative analysis of the resulting specific fragments indicates that the mtDNA of any individual mammal is predominantly a single molecular clone. Gel analysis of specific cleavage products has proven quite sensitive in detecting differences in mtDNA: mtDNAs from the more distantly related mammals studied (e.g., donkey and dog) are found to have few bands in common and very closely related mammals (e.g., donkey and horse) share only about 50% of their bands. This procedure has detected several intraspecies mtDNA differences. Six distinct human patterns have been found, with one pattern usually differing from another in two or three bands. mtDNAs from different organs of single individuals have also been analyzed, and no differences have been found.
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PMID:Specific cleavage analysis of mammalian mitochondrial DNA. 106 Jan 30

Genomic DNA size was measured in clinical isolates of Haemophilus influenzae by Pulsed-Field Gel Electrophoresis of DNA restriction fragments. Because of the high (64%) A+T content of H. influenzae DNA, restriction enzymes that recognize sequences with at least four GC base pairs were expected to be rare cutters. Five enzymes that produced fragments greater than 200 kb in size were used to digest intact chromosomes and fragments resolved by TAFE and/or FIGE: ApaI (GGGCCC), EagI (CGGCCG), NotI (GCGGCCGC), RsrI (CGGA/TCCG), and SmaI (CCCGGG). All five had recognition sequences with at least six GC base pairs. The genomic DNA size of H. influenzae serotype b, estimated with ApaI, EagI, NotI, RsrII, and SmaI, is 1,950 kb.
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PMID:Determination of genome size of Haemophilus influenzae Sb: analysis of DNA restriction fragments. 128 88

Outer membrane protein P6 is an important antigen expressed on the surface of all strains of Haemophilus influenzae. The predicted amino acid sequence of P6 contains a region of alpha helices that shares sequence identity with a family of helix-turn-helix DNA-binding proteins. A search for sequence-specific binding sites that resemble an operator region within the gene revealed a sequence with striking homology to the consensus operator sequence for lambda Cro and repressor. To test the hypothesis that P6 binds its own gene, purified P6 on nitrocellulose was probed with plasmid DNA containing the P6 gene. P6 bound the P6 gene in this Southwestern blot assay. To further test the observation, gel shift analysis was performed. Gel shift assays using a P6-specific monoclonal antibody demonstrated that P6 in crude cell extracts binds to the region of the gene containing the putative binding site. Competition with a synthetic oligonucleotide corresponding to the putative binding site inhibited binding of P6 to the P6 gene on nitrocellulose and in the gel shift assay. In addition, this oligonucleotide bound directly to P6 on nitrocellulose. Finally, DNase footprinting confirmed that P6 bound specifically to the same region of the P6 gene. These results indicate that P6 binds to a sequence-specific site within its own gene, suggesting that P6 regulates its own expression. This represents the first example of a Gram-negative outer membrane protein binding to its own gene and has potentially important implications as a mechanism for regulation of expression of outer membrane antigens.
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PMID:Outer membrane protein P6 of Haemophilus influenzae binds to its own gene. 156 Jul 83

Chronic bronchial inflammation is associated with migration of large numbers of granulocytes into the bronchial tree. A study was designed to find out whether products of bacteria commonly isolated in chronic bronchial infection stimulate neutrophil migration in vitro. Neutrophils from healthy donors were studied by a modified Boyden chamber technique. Bacterial culture filtrates stimulated neutrophil migration over a wide dilution range and the chemotactic activity was heat stable. Culture filtrates derived from Pseudomonas aeruginosa, Streptococcus pneumoniae, and Haemophilus influenzae were significantly chemokinetic and directionally chemotactic, whereas filtrates from Staphylococcus aureus were only chemotactic. Gel filtration of S aureus and P aeruginosa culture filtrates yielded high, medium, and low molecular weight fractions showing chemotactic activity. S pneumoniae and H influenzae yielded fractions with only low molecular weight chemotactic activity. Neutrophil chemotactic responses, occurring in response to all bacterial species tested, appear to represent a defence mechanism by the host. Chemoattractant activity may, however, contribute to bronchial damage mediated by products released from continuously attracted, activated neutrophils.
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PMID:Effect of bacterial products on neutrophil migration in vitro. 211 19

A heat- and acid-stable protein which bound both native and denatured DNA but not RNA was extensively purified from extracts of Haemophilus influenzae Rd strain com-58-A. The active species had an apparent subunit molecular weight of 15,000. The interaction of the protein with denatured DNA appeared to be cooperative, as judged by the sigmoid shapes of binding curves. This cooperativity increased with increasing ionic strength and was more pronounced with sodium ions than with potassium ions. Gel filtration suggested that the native protein formed aggregates in solution. The presence of the binding protein protected single-stranded DNA from the action of S1 endonuclease; approximately 30 nucleotide residues were protected per subunit equivalent of protein. The number of subunit equivalents per cell of this protein has been estimated at 10,000. The protein, which we designate DNA-binding protein II, is most probably a major histone-line protein of H. influenzae.
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PMID:DNA-binding proteins of Haemophilus influenzae: purification and characterization of a major intracellular binding protein. 630 11

Nontypeable Haemophilus influenzae commonly causes infections in the lower and upper respiratory tract, although the mechanisms of its colonization and persistence in the airways are unclear. Culture filtrates from six clinical isolates of this bacterium were assessed for their abilities to influence neutrophil function in vitro. Each culture filtrate was assessed on six separate occasions with neutrophils obtained from six different donors. During the log and early stationary phases of growth (0 to 18 h), culture filtrates contained primarily neutrophil chemokinetic activity but no activity affecting neutrophil migration toward the chemotactic factors N-formyl-L-methionyl-L-leucyl-L-phenylalanine and leukotriene B4. In contrast, filtrates obtained after 24 h of culture contained factors which inhibited neutrophil migration toward both of these chemotactic factors. This chemotaxis-inhibitory activity persisted between 24 and 72 h of bacterial culture, and it was not associated with the presence of either chemotactic or chemokinetic activity as assessed by checkerboard analysis. Gel filtration of pooled 72-h filtrates yielded three major peaks of chemotaxis-inhibitory activity. Endotoxin was present together with two other low-molecular-mass hydrophobic factors of approximately 8 and 2 kDa. These low-molecular-mass factors are chloroform insoluble and heat stable, and they are inactivated by protease, periodate, and diborane reduction. Activity was completely retained on a wheat germ agglutinin column, and it could be eluted with N-acetyl-D-glucosamine. These data suggest that inhibitory activity is associated with N-acetyl-D-glucosamine-containing glycopeptides, possibly derived from the bacterial cell wall. The production of these compounds may contribute to the persistence of this bacterium in vivo by inhibiting neutrophil chemotaxis in the microenvironment of the respiratory mucosa.
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PMID:Inhibition of human neutrophil migration in vitro by low-molecular-mass products of nontypeable Haemophilus influenzae. 838 63

The physical maps the Haemophilus influenzae Sb genomes were constructed by the comparison of restriction fragment sizes of complete single and double digests, as well as by the analysis of partial DNA digests. Sites for four restriction endonucleases NotI, RsrII, SmaI and SrfI were located on the bacterial chromosomes, which are circular, and 2028 and 2045 kb in circumferences. The order of fragments was deduced from fragment patterns of the combinations of double digestion and by two-dimensional Field-Inversion Gel Electrophoresis (FIGE).
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PMID:Physical maps of the chromosomes of Haemophilus influenzae Sb. 879 54

Nontypeable Haemophilus influenzae (NTHi) is an important pathogen responsible for otitis media in children and of pneumonitis in adults with depressed resistance. NTHi is acapsular and, therefore, capsular polysaccharide-based vaccines are ineffective for preventing infections by this pathogen. Recently it was found that a detoxified lipooligo-saccharide (LOS) conjugate from NTHi 9274 induced bactericidal antibodies effective against a large number of NTHi isolates, and conferred protection against NTHi otitis media in chinchillas (X.-X.Gu et al., 1996, Infect. Immun.,64, 4047-4053; X. -X.Gu et al., 1997., Infect. Immun.,65, 4488-4493). In this paper we report the chemical character-ization of the LOS from NTHi 9274 LOS. NTHi is capable of expressing a heterogenous population of LOS exhibited by multiple oligosaccharide (OS) epitopes. OSs released from the LOS of NTHi 9274 by mild acid hydrolysis were purified using Bio-Gel P4 gel permeation chromatography. The OSs were characterized by glycosyl composition analysis, glycosyl linkage analysis, nuclear magnetic resonance spectroscopy (NMR), fast atom bombardment mass spectro-metry (FAB-MS), matrix-assisted laser desorption time of flight mass spectro-metry (MALDITOF-MS), and tandem MS/MS. At least 17 different OS molecules were observed. These contained variable glycosyl residues, phosphate (P), and phospho-ethanolamine (PEA) substituents. These molecules contained either three, four, or five hexoses, and all contained four heptosyl residues. The four heptosyl residues consisted of one D,D-Hep and three L,D-Hep. Dephosphorylation of the OSs with aqueous 48% hydrofluoric acid (HF) reduced the number of molecules to about to seven; Hex(1)-(7)Hep(4)Kdo(1). Of these seven, Hex(2)Hep(4)Kdo(1), Hex(3)Hep(4)Kdo(1), and Hex(4)Hep(4)Kdo(1)were the major constituents. Thus, this NTHi LOS preparation is very heterogeneous, and contains structures different from those previously published for Haemophilus influenzae. The tandem MS/MS analysis and glycosyl linkage data suggest that the LOS oligosaccharides have the following structures where Hex is either a Glc or Gal residue.
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PMID:The structural heterogeneity of the lipooligosaccharide (LOS) expressed by pathogenic non-typeable Haemophilus influenzae strain NTHi 9274. 1056 62

The crystal structure of the Haemophilus influenzae protein HI1480 was determined at 2.1-A resolution. The amino acid sequence of HI1480 is unique, having no homology with other known protein sequences. The protein adopts a novel alpha+beta fold, and associates into a dimer of tightly associated dimers. The tight dimers are formed by intermolecular interactions that are mediated by an antiparallel beta-barrel involving both monomers. Helical regions of two dimers mediate the tetramer formation. The helical region contains a four-helix bundle that has been seen only in the anticodon binding domains of class I tRNA synthetases. A cluster of four residues, Tyr18, Arg134, Glu26, and Lys12 is located in a depression formed at the four-helix bundle/ beta-barrel interface. The arrangement is suggestive of an active center, possibly a catalytic site. The HI1480 gene is located within the Mu-like prophage region of H. influenzae, has no homology to bacteriophage genes, and is flanked by transposases. Hence, this is an example of horizontal transfer from an unknown organism. Gel mobility shift assays revealed that HI1480 binds DNA and RNA molecules. Double-stranded DNA is favored over single-stranded DNA, and longer DNA molecules are bound better than shorter ones.
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PMID:Novel structure and nucleotide binding properties of HI1480 from Haemophilus influenzae: a protein with no known sequence homologues. 1522 88


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