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)

Two-dimensional gel electrophoresis separates several hundred protein molecules in one single experiment and is efficiently used to study the products expressed by different genomes. Low-copy-number gene products are invisible on a stained two-dimensional map and must be enriched such that sufficient amounts are present for visualization and identification. We investigated the enrichment of proteins of the bacterium Haemophilus influenzae by chromatography on immobilized heparin which has affinity for growth and protein biosynthesis factors. Total soluble proteins of the microorganism were fractionated on Heparin-Actigel which resulted in enrichment of approximately 160 proteins. The eluates, representing about 40% of the applied proteins, were analyzed by two-dimensional gel electrophoresis and the protein spots were characterized by amino acid composition analysis and matrix-assisted laser desorption ionization mass spectrometry. The proteins enriched by chromatography on the heparin gel were not exclusively low-copy-number gene products and they did not exclusively belong to one single class of proteins. The proteins that bound to the heparin gel are indicated in a two-dimensional protein map which includes more than 110 newly identified proteins.
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PMID:Two-dimensional map of Haemophilus influenzae following protein enrichment by heparin chromatography. 923 78

The design of efficient protein purification protocols is a scientific challenge and can be facilitated by the use of master protein enrichment or purification steps. A master purification step is in principle a list including the major proteins expected to be present in the various fractions collected from a particular enrichment process. Consideration of a master step in the design of a purification pathway can reduce the time and effort usually invested in "trial and error" approaches. Moreover, master purification steps will certainly become valuable tools in the isolation of proteins today designated as hypothetical or predicted coding regions, resulting from the sequencing of the various genomes, and for which no information on their purification exists. The construction of such a master step consists of performance of the protein separation by the particular chromatographic method, analysis by two-dimensional polyacrylamide gel electrophoresis, and identification by mass spectrometry of the proteins present in each fraction. This can be efficiently accomplished now thanks to developments in two-dimensional gel technology and large-scale sample throughput mass spectrometry. Here we present an example of construction of a master protein enrichment step using the soluble protein fraction of the bacterium Haemophilus influenzae and applying Heparin chromatography.
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PMID:Design of protein purification pathways: application to the proteome of Haemophilus influenzae using heparin chromatography. 975 58

Haemophilus somnus can cause a devastating fibrinopurulent meningitis with thrombotic vasculitis and encephalitis in cattle. The mechanisms used by H. somnus to migrate from the bloodstream into the central nervous system (CNS) are unknown. In this study, we demonstrate that H. somnus adheres to, but does not invade, bovine brain endothelial cells (BBEC) in vitro. The number of adherent H. somnus was significantly increased by prior activation of the BBEC with tumor necrosis factor alpha (TNF-alpha). Addition of exogenous glycosaminoglycans significantly reduced H. somnus adherence to resting and TNF-alpha-activated BBEC. Heparinase digestion of the endothelial cell's glycocalyx or sodium chlorate inhibition of endothelial cell sulfated glycan synthesis significantly reduced the number of adherent H. somnus. In contrast, addition of hyaluronic acid, a nonsulfated glycosaminoglycan, had no inhibitory effect. These findings suggest a critical role for both cellular activation and sulfated glycosaminoglycans in adherence of H. somnus to BBEC. Using heparin-labeled agarose beads, we demonstrated a high-molecular-weight heparin-binding protein expressed by H. somnus. Heparin was also shown to bind H. somnus in a 4 degrees C binding assay. These data suggest that heparin-binding proteins on H. somnus could serve as initial adhesins to sulfated proteoglycans on the endothelial cell surface, thus contributing to the ability of H. somnus to infect the bovine CNS.
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PMID:Roles of cellular activation and sulfated glycans in Haemophilus somnus adherence to bovine brain microvascular endothelial cells. 1692 25