Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.17 (lysozyme)
 21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The mechanism of uptake of aminoglycosides across the outer membrane of Escherichia coli was reevaluated. Porin-deficient mutants showed no alteration in gentamicin or kanamycin susceptibility. Furthermore, the influence of kanamycin on intrinsic tryptophan fluorescence of porin OmpF (Y. Kobayashi, and T. Nakae, Eur. J. Biochem. 151:231-236, 1985) was shown to be strongly influenced by protein concentration and EDTA. This led to the hypothesis that aminoglycoside-mediated increases and decreases in intrinsic tryptophan fluorescence were due to aggregation-disaggregation of OmpF mediated by interaction at a divalent cation binding site on OmpF. Gentamicin, kanamycin, and polymyxin B increased E. coli outer membrane permeability to the hydrophobic fluorescent compound 1-N-phenyl-naphthylamine (NPN) and the peptidoglycan-degrading enzyme lysozyme. Addition of Mg2+ blocked these permeabilizing activities. Furthermore, gentamicin and polymyxin B bound to Mg(2+)-binding sites on E. coli lipopolysaccharide, as determined in dansyl polymyxin displacement experiments. A polymyxin-resistant, lipopolysaccharide-altered pmr mutant of E. coli had a fourfold-lower MIC of gentamicin and kanamycin and was more poorly permeabilized to 1-N-phenylnaphthylamine than was its parent strain. These data were consistent with uptake of aminoglycosides across the E. coli outer membrane by the self-promoted uptake mechanism.
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PMID:Interaction of aminoglycosides with the outer membranes and purified lipopolysaccharide and OmpF porin of Escherichia coli. 165 59

Biopsies from the temporal artery of 32 patients suspected of giant-cell arteritis were evaluated retrospectively by light microscopy, histochemical, and immunohistochemical methods, as well as by transmission electron microscopy (TEM). At the clinical follow-up the 32 patients included four clinical groups: temporal arteritis (8 patients), polymyalgia rheumatica (10 patients), rheumatoid arthritis (4 patients), and a group of miscellaneous diseases unrelated to inflammatory rheumatic diseases (10 patients). There were a number of similarities between age-related alterations in the arteries and the changes in giant-cell arteritis. The most important differences were the inflammatory cellular infiltration of the media, the perifocal accumulation of fibronectin, and the occurrence of deposits of fibrin/fibrinogen and fibrin/fibrinogen degradation products. In addition, alpha-2 macroglobulin, lysozyme and factor VIII were also noted in giant-cell arteritis. The alterations in giant-cell arteritis show a number of similarities to the changes following experimental vascular injury of the rabbit aorta. The nature of the findings in human giant-cell arteritis, as well as the similarity to the experimental arteritis, indicate that giant-cell arteritis may reflect a non-specific reaction to injury, independent of the cause of the disease.
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PMID:Giant-cell arteritis. Histological, immunohistochemical and electronmicroscopic studies. 244 62