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

Staphylococcus aureus accumulated cardiolipin (CL) and lost phosphatidylglycerol (PG) during the stationary phase of growth. The minor lipids, phosphatidylethanolamine and phosphatidylglucose, also accumulated, whereas the lysylphosphatidylglycerol (LPG) content of the membrane remained constant as stationary phase continued. During exponential growth, the proportions and total content of phospholipids per cell remained constant. The metabolism of the phospholipids was examined under these conditions. In pulse-chase experiments, the phospholipids lost (14)C from the glycerols slower than (32)P. When the phospholipids were labeled with (14)C glycerol, the unacylated glycerols of PG and LPG lost (14)C, whereas the diacylated glycerols either accumulated or did not lose (14)C. In all experiments, the PG showed a more rapid metabolism than the LPG. When staphylococcal CL was hydrolyzed by Haemophilus parainfluenzae CL-specific phospholipase D into phosphatidic acid (PA) and PG, the incorporation of (32)P into both of the phosphates of CL was found to be parallel at both the PG and PA ends of the molecule. However, the specific activity of the (32)P at the PA end was twice that at the PG end of the molecule. The PG end of the CL apparently came from a portion of the cellular PG pool with about 20% the specific activity of the total cellular PG. The turnover of two of the glycerols of the PG portion of CL was like that of the cellular PG. The diacylated glycerol of the PG and of CL and of the membrane PG showed neither turnover nor incorporation of (14)C. Half of the radioactivity was lost from the middle glycerol of CL and the free glycerol of the cellular PG in one bacterial doubling. The diacylated glycerol from the other end of the CL molecule (the PA end) lost radioactivity almost as rapidly as the middle glycerol for 10 min. After the initial rapid loss, the turnover slowed to a rate 10 times slower than the middle glycerol, indicating that the (14)C was actually accumulating at this end of the molecule. The phosphates and glycerols involved in the hydrolysis and resynthesis of the CL molecule during exponential growth in S. aureus apparently come from different pools of PG.
 ...
PMID:Metabolism of phosphatidylglycerol, lysylphosphatidylglycerol, and cardiolipin of Staphylococcus aureus. 512 4

Examination of phospholipid metabolism in Haemophilus parainfluenzae with inhibitors of various cellular functions indicated that macromolecular synthesis and lipid metabolism can be dissociated at least for a short time. Two classes of inhibitors have relatively specific effects on cardiolipin (CL) metabolism. Pentachlorophenol and p-hydroxymercuribenzoate blocked CL synthesis but allowed CL hydrolysis to phosphatidic acid and phosphatidyl glycerol (PG); 3,3',4,5'-tetrachlorosalicylanilide (TCS) and carbonyl cyanide m-chlorophenylhydrazone (m-CCCP) blocked CL hydrolysis with the stoichiometric accumulation of CL. It appeared as if TCS and m-CCCP inhibited a vital activity coupled with the hydrolysis of CL by the highly active, CL-specific phospholipase D found in this organism. Because TCS and m-CCCP are thought to act by destroying the proton gradient thereby interrupting energy-dependent transport, it is possible that a highly active portion of the cellular CL could be coupled to some phase of this process.
 ...
PMID:Consequences of the inhibition of cardiolipin metabolism in Haemophilus parainfluenzae. 513 31

The principal lipids associated with the electron transport membrane of Haemophilus parainfluenzae are phosphatidylethanolamine (78%), phosphatidylmonomethylethanolamine (0.4%), phosphatidylglycerol (18%), phosphatidylcholine (0.4%), phosphatidylserine (0.4%), phosphatidic acid (0.2%), and cardiolipin (3.0%). Phospholipids account for 98.4% of the extractible fatty acids. There are no glycolipids, plasmalogens, alkyl ethers, or lipo amino acid esters in the membrane lipids. Glycerol phosphate esters derived from the phospholipids by mild alkaline methanolysis were identified by their staining reactions, mobility on paper and ion-exchange column chromatography, and by the molar glycerol to phosphate ratios. Eleven diacyl phospholipids can be separated by two-dimensional thin-layer chromatography. Each lipid served as a substrate for phospholipase D, and had a fatty acid to phosphate ratio of 2:1. Each separated diacyl phospholipid was deacylated and the glycerol phosphate ester was identified by paper chromatography in four solvent systems. Of the 11 separated phospholipids, 3 were phosphatidylethanolamines, 2 were phosphatidylserines, and 2 were phosphatidylglycerols. Phosphatidylcholine, cardiolipin, and phosphatidic acid were found at a single location. Phosphatidylmonomethylethanolamine was found with the major phosphatidylethanolamine. Three distinct classes of phospholipids are separable according to their relative fatty acid compositions. (i) The trace lipids consist of two phosphatidylethanolamines, two phosphatidylserines, phosphatidylcholine, phosphatidic acid, and a phosphatidylglycerol. Each lipid represents less than 0.3% of the total lipid phosphate. These lipids are characterized by high proportions of the short (C(10) to C(14)) and long (C(19) to C(22)) fatty acids with practically no palmitoleic acid. (ii) The major phospholipids (93% of the lipid phosphate) are phosphatidylethanolamine, phosphatidylmonomethylethanolamine, and phosphatidylglycerol. These lipids contain a low proportion of the short (<C(14)) and long (>C(19)) fatty acids. Palmitic and palmitoleic acids represent over 80% of the total fatty acids. (iii) The fatty acid composition of the cardiolipin is intermediate between the other two classes. Both palmitoleic and the longer fatty acids represent a significant proportion of the total fatty acid.
 ...
PMID:Lipid composition of the electron transport membrane of Haemophilus parainfluenzae. 568 94

Freshly collected cerumen (dry form) suspended at a concentration of 3% in glycerol-sodium bicarbonate buffer showed bactericidal activity against some strains of bacteria tested. This suspension reduced the viability of Haemophilus influenzae, Escherichia coli K-12, and Serratia marcescens by more than 99%, whereas the viability of two Pseudomonas aeruginosa isolates, E. coli K-1, Streptococcus, and two Staphylococcus aureus isolates of human origin was reduced by 30 to 80%. The results support the hypothesis that cerumen functions to kill certain foreign organisms which enter the ear canal.
 ...
PMID:Bactericidal activity of cerumen. 744 22

We report the purification, molecular cloning, and characterization of a 40-kDa glycerophosphodiester phosphodiesterase homolog from Borrelia hermsii. The 40-kDa protein was solubilized from whole organisms with 0.1% Triton X-100, phase partitioned into the Triton X-114 detergent phase, and purified by fast-performance liquid chromatography (FPLC). The gene encoding the 40-kDa protein was cloned from a B. hermsii chromosomal DNA lambda EXlox expression library and identified by using affinity antibodies generated against the purified native protein. The deduced amino acid sequence included a 20-amino-acid signal peptide encoding a putative leader peptidase II cleavage site, indicating that the 40-kDa protein was a lipoprotein. Based on significant homology (31 to 52% identity) of the 40-kDa protein to glycerophosphodiester phosphodiesterases of Escherichia coli (GlpQ), Bacillus subtilis (GlpQ), and Haemophilus influenzae (Hpd; protein D), we have designated this B. hermsii 40-kDa lipoprotein a glycerophosphodiester phosphodiesterase (Gpd) homolog, the first B. hermsii lipoprotein to have a putative functional assignment. A nonlipidated form of the Gpd homolog was overproduced as a fusion protein in E. coli BL21(DE3)(pLysE) and was used to immunize rabbits to generate specific antiserum. Immunoblot analysis with anti-Gpd serum recognized recombinant H. influenzae protein D, and conversely, antiserum to H. influenzae protein D recognized recombinant B. hermsii Gpd (rGpd), indicating antigenic conservation between these proteins. Antiserum to rGpd also identified native Gpd as a constituent of purified outer membrane vesicles prepared from B. hermsii. Screening of other pathogenic spirochetes with anti-rGpd serum revealed the presence of antigenically related proteins in Borrelia burgdorferi, Treponema pallidum, and Leptospira kirschneri. Further sequence analysis both upstream and downstream of the Gpd homolog showed additional homologs of glycerol metabolism, including a glycerol-3-phosphate transporter (GlpT), a glycerol-3-phosphate dehydrogenase (GlpD), and a thioredoxin reductase (TrxB).
 ...
PMID:Sequence analysis and characterization of a 40-kilodalton Borrelia hermsii glycerophosphodiester phosphodiesterase homolog. 907 9

The glycerol facilitator is one of the few known examples of bacterial solute transport proteins that catalyse facilitated diffusion across the cytoplasmic membrane. A second protein, glycerol kinase, is involved in entry of external glycerol into cellular metabolism by trapping glycerol in the cytoplasm as sn-glycerol 3-phosphate. Evidence is presented that glycerol transport in Pseudomonas aeruginosa is mediated by a similar transport system. The genes encoding the glycerol facilitator, glpF, and glycerol kinase, glpK, were isolated on a 4.5 kb EcoRI fragment from a chromosomal mini-library by functional complementation of an Escherichia coli glpK mutant after establishing a map of the chromosomal glpFK region with the help of a PCR-amplified glpK segment. The nucleotide sequence revealed that glpF is the promoter-proximal gene of the glpFK operon. The glycerol facilitator and glycerol kinase were identified in a T7 expression system as proteins with apparent molecular masses of 25 and 56 kDa, respectively. The identities of the glycerol facilitator and glycerol kinase amino acid sequences with their counterparts from Escherichia coli were 70 and 81%, respectively; this similarity extended to two homologues in the genome sequence of Haemophilus influenzae. A chromosomal delta glpFK mutant was isolated by gene replacement. This mutant no longer transported glycerol and could no longer utilize it as sole carbon and energy source. Two ORFs, orfX and orfY, encoding a putative regulatory protein and a carbohydrate kinase of unknown function, were located upstream of the glpFK operon.
 ...
PMID:Structure and gene-polypeptide relationships of the region encoding glycerol diffusion facilitator (glpF) and glycerol kinase (glpK) of Pseudomonas aeruginosa. 914 91

To identify potential opsonic targets of Treponema pallidum subsp. pallidum, a treponemal genomic expression library was constructed and differentially screened with opsonic and non-opsonic T. pallidum antisera. This method identified an immunoreactive clone containing an open reading frame encoding a 356 residue protein. Nucleotide sequence analysis demonstrated the translated protein to be a homologue of glycerophosphodiester phosphodiesterase, a glycerol metabolizing enzyme previously identified in Haemophilus influenzae, Escherichia coli, Bacillus subtilis and Borrelia hermsii. Sequence alignment analyses revealed the T. pallidum and H. influenzae enzymes share a high degree of amino acid sequence similarity (72%), suggesting that in T. pallidum this molecule may be surface exposed and involved in IgD binding as is the case with its counterpart in H. influenzae.
 ...
PMID:Identification of the Treponema pallidum subsp. pallidum glycerophosphodiester phosphodiesterase homologue. 931 Nov 29

The gene (denoted aroQp.pheA) encoding the bifunctional P-protein (chorismate mutase-P/prephenate dehydratase) from Xanthomonas campestris was cloned. aroQp.pheA is essential for L-phenylalanine biosynthesis. DNA sequencing of the smallest subclone capable of functional complementation of an Escherichia coli phenylalanine auxotroph revealed a putative open reading frame (ORF) of 1200 bp that would encode a 43,438-Da protein. AroQp.PheA exhibited 51% amino acid identity with a Pseudomonas stutzeri homologoue and greater than 30% identities with AroQp.PheA proteins from Haemophilus influenzae, Neisseria gonorrhoeae, and a number of enteric bacteria. AroQp.PheA from X. campestris, when expressed in E. coli, possesses a 40-residue amino-terminal extension that is lysine-rich and that is absent in all of the AroQp.PheA homologues known at present. About 95% of AroQp.PheA was particulate and readily sedimented by low-speed centrifugation. Soluble preparations of cloned AroQp.PheA exhibited a native molecular mass of 81,000 Da, indicating that the active enzyme species is a homodimer. These preparations were unstable after purification of about 40-fold, even in the presence of glycerol, which was an effective protectant before fractionation. When AroQp.PheA was overproduced by a T7 translation vector, unusual inclusion bodies having a macromolecular structure consisting of protein fibrils were observed by electron microscopy. Insoluble protein collected at low-speed centrifugation possessed high catalytic activity. The single band obtained via SDS-PAGE was used to confirm the translational start via N-terminal amino acid sequencing. A perspective on the evolutionary relationships of monofunctional AroQ and PheA proteins and the AroQp.PheA family of proteins is presented. A serC gene located immediately upstream of X. campestris aroQp.pheA appears to reflect a conserved gene organization, and both may belong to a single transcriptional unit.
 ...
PMID:The aroQ and pheA domains of the bifunctional P-protein from Xanthomonas campestris in a context of genomic comparison. 968 22

The aim of this study was to compare the efficacy of conservation by freezing the strains of Haemophilus influenzae at -20 degrees C and -70 degrees C. Skim milk supplemented with glucose, yeast extract and glycerol allowed highest viability of H. influenzae both at -20 degrees C and -70 degrees C from the media analyzed. Trypticase soy broth and brain heart infusion broth supplemented with glycerol, allowed excellent recovery. Use of cotton swaps as supporting material, with or without addition of cryoprotective agents, did not modify H. influenzae viability after six months of storage. Concentration of the initial inoculum positively affected viability when stored at -20 degrees C. Initial concentration did not influence survival after storage at -70 degrees C. Thawing at room temperature should not exceed 3 h as to get highest survival percentage.
 ...
PMID:A comparative study of preservation and storage of Haemophilus influenzae. 1139 34

Protein D, having a glycerol-3-phosphodiester phosphodiesterase activity, is found at the surface of all Haemophilus influenzae strains and is a possible virulence factor. In the present study, the involvement of protein D in the entry of NTHi into human monocytic cells is reported. Primary monocytes and the monocytic cell lines U-937 and THP-1 were infected with NTHi strain 772 and the mutant 772 Delta hpd 1 (lacking the gene for protein D). NTHi 772 adhered to and entered monocytic cells up to four-fold more efficiently compared to 772 Delta hpd 1. When an Escherichia coli transformant expressing protein D was incubated with monocytic cells, the number of intracellular bacteria increased 1.6-fold compared to protein D-deficient controls. Any correlation between internalization and phosphorylcholine expression was not detected. In conclusion, our data suggest that surface-expressed protein D promotes the adherence of NTHi to human monocytes leading to a higher number of internalized bacteria.
 ...
PMID:Protein D expression promotes the adherence and internalization of non-typeable Haemophilus influenzae into human monocytic cells. 1150 Jan


<< Previous 1 2 3 Next >>