Topic
Lysis
About: Lysis is a research topic. Over the lifetime, 6072 publications have been published within this topic receiving 216978 citations.
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TL;DR: The biological activity of the PA, when combined with excess lethal factor in the macrophage cell lysis assay, was comparable to previously reported values.
Abstract: Bacillus anthracis, the etiologic agent for anthrax, produces two bipartite, AB-type exotoxins, edema toxin and lethal toxin. The B subunit of both exotoxins is an Mr 83,000 protein termed protective antigen (PA). The human anthrax vaccine currently licensed for use in the United States consists primarily of this protein adsorbed onto aluminum oxyhydroxide. This report describes the production of PA from a recombinant, asporogenic, nontoxigenic, and nonencapsulated host strain of B. anthracis and the subsequent purification and characterization of the protein product. Fermentation in a high-tryptone, high-yeast-extract medium under nonlimiting aeration produced 20 to 30 mg of secreted PA per liter. Secreted protease activity under these fermentation conditions was low and was inhibited more than 95% by the addition of EDTA. A purity of 88 to 93% was achieved for PA by diafiltration and anion-exchange chromatography, while greater than 95% final purity was achieved with an additional hydrophobic interaction chromatography step. The purity of the PA product was characterized by reversed-phase high-pressure liquid chromatography, sodium dodecyl sulfate (SDS)-capillary electrophoresis, capillary isoelectric focusing, native gel electrophoresis, and SDS-polyacrylamide gel electrophoresis. The biological activity of the PA, when combined with excess lethal factor in the macrophage cell lysis assay, was comparable to previously reported values.
80 citations
TL;DR: It was suggested that PBP1A/1B do not have a specific function in either elongation or constriction, rather, they seem to have a general activity on the basis of which the other synthesizing PBP perform their special tasks.
80 citations
01 Jan 1992
TL;DR: Although atypical tetracyclines promoted lysis in intact organisms, they did not cause lysis of E. coli spheroplasts, indicating that the analogs do not directly destroy the cytoplasmic membrane.
Abstract: 6-thiatetracycline, anhydrochlortetracycline, and4-epi-anhydrochlortetracycline, werebactericidal andcaused thelysis ofEscherichia coli accompaniedbytherelease ofthecytoplasmic enzyme1-galactosidase into thesupernatant. Examination byelectron microscopy demonstrated that cells exposed tothese analogs underwent markedmorphological alterations that included theformation ofnumerous ghosts andtheappearance ofcellular debris intheculture medium. Although atypical tetracyclines promoted lysis inintact organisms, theydidnotcauselysis ofE.coli spheroplasts, indicating that theanalogs donotdirectly destroy thecytoplasmic membrane. Theseagents may promote cell lysis anddeath byinterfering withthemembrane's electrochemical gradient, whichinturnleads tostimulation ofautolytic enzyme activity andcellular lysis. Theresults support recently published datawhich indicate that tetracyclines aredivisible into twoclasses onthebasis oftheir modesofaction.
80 citations
TL;DR: The data presented indicate that the bacteriolytic response of growing cells to Triton X-100 required the expression of the cellular autolytic enzyme system and was most likely due to an effect of the surfactant on components of the autolytics system that are associated with the cytoplasmic membrane.
Abstract: Lysis of exponential-phase cultures of Streptococcus faecalis ATCC 9790 was induced by exposure to both anionic (sodium dodecyl sulfate) and nonionic (Triton X-100) surfactants. Lysis in response to sodium dodecyl sulfate was effective only over a limited range of concentrations, whereas Triton X-100-induced lysis occurred over a broad range of surfactant concentrations. The data presented indicate that the bacteriolytic response of growing cells to Triton X-100: (i) was related to the ratio of surfactant to cells and not the surfactant concentration per se; (ii) required the expression of the cellular autolytic enzyme system; and (iii) was most likely due to an effect of the surfactant on components of the autolytic system that are associated with the cytoplasmic membrane. The possibility that Triton X-100 may induce cellular lysis by releasing a lipid inhibitor of the cellular autolytic enzyme is discussed.
79 citations
TL;DR: The concentration of PAHs and catechol 2,3-dioxygenase DNA in PAH-contaminated sediment undergoing an ex situ compost process was quantified by competitive PCR over a period of 16 weeks and was found to correlate.
79 citations