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: When Escherichia coli containing the plasmid ptac11 is induced with 10−4 M isopropyl‐β‐thiogalactopyranoside (IPTG), 90% of the β‐lactamase activity of an overnight culture is present in the medium and the level of two membrane proteins, OmpA and OmpC, is decreased.
Abstract: When Escherichia coli containing the plasmid ptac11 is induced with 10(-4) M isopropyl-beta-thiogalactopyranoside (IPTG), 90% of the beta-lactamase activity of an overnight culture is present in the medium. The high extracellular activity of beta-lactamase does not result from cell lysis but from an increase in the permeability of the outer membrane. The excreting cells release several other periplasmic enzymes into the extracellular fluid and are more sensitive to lysis by detergents. It was also shown that in these cells the level of two membrane proteins, OmpA and OmpC, is decreased. None of these phenomena were observed with the plasmid pDW17, which has a mutation in the tac promoter that reduces its activity to one fourth of the tac promoter.
79 citations
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TL;DR: The AgNP was successfully synthesised from soil isolated bacterium Bacillus subtilis and treated microalga to disrupt its cell wall to release lipids and carbohydrates, causing cell wall damages evidenced by LDH assay and SEM.
79 citations
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TL;DR: The REAP procedure is performed at low temperature and takes <2 min, which minimizes protein degradation, protein modification, and diffusion of soluble proteins out of the nuclear compartment while maintaining the integrity of protein complexes.
Abstract: This protocol presents a rapid, efficient, and practical (REAP) method to separate nuclei from cultured cells in vitro with as little damage and contamination as possible. The REAP procedure is performed at low temperature and takes <2 min, which minimizes protein degradation, protein modification, and diffusion of soluble proteins out of the nuclear compartment while maintaining the integrity of protein complexes. A mild detergent, NP-40, is used together with mild mechanical shearing to disrupt the plasma membrane, leaving the nuclear membrane intact. The REAP method can be used with various cell lines grown in vitro and requires minimal optimization. The isolated nuclei are suitable for numerous downstream applications (e.g., western blotting, 2D gel electrophoresis, and immunoprecipitation). If desired, aliquots of whole-cell lysate and the cytoplasmic fraction can be saved for comparison.
79 citations
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TL;DR: The results imply that the leukotoxin has membranolytic activity, producing pores in target cells with a functional diameter approximately the size of maltose (0.96 nm), which suggests that the toxin may not be sufficient to cause lysis without activation of additional effector mechanisms.
Abstract: Actinobacillus actinomycetemcomitans leukotoxin permeabilized the plasma membrane of HL-60 promyelocytic leukemia cells, resulting in colloid osmotic lysis. These events were associated with efflux of 51chromium (from prelabeled cells), influx of propidium iodide, and ultrastructural evidence of cellular damage. Target cell lysis was inhibited by procedures which may interfere with the initial interaction of the toxin with the plasma membrane. For example, washing cultures (to dilute and remove toxin) or the addition of monoclonal antibodies (to neutralize toxin) or trypsin (to inactivate toxin) limited lysis when undertaken within the first 5 min of the reaction. The extent of injury was also diminished when radiolabeled HL-60 cells were exposed to toxin in the presence of unlabeled, toxin-sensitive cells (e.g., HL-60 cells or human neutrophils) or certain toxin-resistant target cells (e.g., human K562 erythroleukemia cells). This suggests that the association of the toxin with the cell membrane may not be sufficient to cause lysis without activation of additional effector mechanisms. The addition of specific trivalent (e.g., La3+) or divalent (e.g., Ca2+ and Zn2+) cations to toxin-treated cells appeared to enhance their capacity to repair or minimize the extent of toxin-mediated membrane damage. Depending on size, certain saccharides served as osmotic protectants: maltose almost completely inhibited radiolabel release, while smaller molecules provided correspondingly less protection. The results imply that the leukotoxin has membranolytic activity, producing pores in target cells with a functional diameter approximately the size of maltose (0.96 nm).
79 citations
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TL;DR: A powerful lytic factor has been obtained in phage lysates of group C streptococci, which is active against streptitis of groups A, C and E and under some conditions group H, and is the factor responsible for ‘nascent’phage lysis.
Abstract: SUMMARY: A powerful lytic factor has been obtained in phage lysates of group C streptococci, which is active against streptococci of groups A, C and E and under some conditions group H. It is the factor responsible for ‘nascent’ phage lysis. The lytic activity remains unaltered by the removal of the phage by high-speed centri-fuging, and also in the presence of phage antiserum. It is active against young and old cell suspensions, live, or killed by chloroform. The activity diminishes in the absence of reducing agents and it is destroyed by protcolytic enzymes. Heat-killed cocci when attacked by the lytic factor become Gram-negative but do not lyse. The addition of a proteolytic enzyme completes lysis. Efforts to demonstrate the release of proteinases from streptococcal suspensions have failed. After lysis the group polysaccharide is free as a hapten and some cell-wall structure remains. M antigen is also present in group A lysates.
79 citations