Showing papers on "Lysis published in 1975"
TL;DR: An improved method is described for the purification of the DNA-dependent RNA polymerase from Escherichia coli, resulting in a yield of 250 mg of holoenzyme from 500 g of cells.
Abstract: An improved method is described for the purification of the DNA-dependent RNA polymerase [ribonucleosidetriphosphate:RNA nucleotidyltransferase, EC 2.7.7.6] from Escherichia coli. The method involves lysozyme-sodium deoxycholate lysis, low-speed centrifugation, precipitation with Polymin P, elution from the Polymin P precipitate, ammonium sulfate precipitation, and chromatography on DNA-cellulose and Bio-Gel A 5m. RNA polymerase is purified to electrophoretic homogeneity in 2 days with a recovery of 45%, resulting in a yield of 250 mg of holoenzyme from 500 g of cells.
1,045 citations
TL;DR: Evidence is presented that penicillin bulge formation is due to the inhibition of proteins 2 and 3 in the absence of inhibition of protein 1.
Abstract: The varied effects of beta-lactam antibiotics on cell division, cell elongation, and cell shape in E. coli are shown to be due to the presence of three essential penicillin binding proteins with distinct roles in these three processes. (A) Cell shape: beta-Lactams that specifically result in the production of ovoid cells bind to penicillin binding protein 2 (molecular weight 66,000). A mutant has been isolated that fails to bind beta-lactams to protein 2, and that grows as round cells. (B) Cell division: beta-Lactams that specifically inhibit cell division bind preferentially to penicillin binding protein 3 (molecular weight 60,000). A temperature-sensitive cell division mutant has been shown to have a thermolabile protein 3. (C) Cell elongation: One beta-lactam that preferentially inhibits cell elongation and causes cell lysis binds preferentially to binding protein 1 (molecular weight 91,000). Evidence is presented that penicillin bulge formation is due to the inhibition of proteins 2 and 3 in the absence of inhibition of protein 1.
973 citations
TL;DR: This chapter discusses a procedure for isolation of DNA from the yeast Saccharomyces cerevisiae that yields a preparation of total-yeast DNA including all three buoyant density species observed in neutral isopycnic cesium chloride gradients.
Abstract: Publisher Summary This chapter discusses a procedure for isolation of DNA from the yeast Saccharomyces cerevisiae This procedure is a modification of an earlier method for isolating DNA from bacteria and has general operations: (1) preparation of osmotically fragile spheroplasts by enzymatic digestion of the cell wall, (2) lysis of the spheroplasts and partial proteolysis of the lysate, (3) deproteinization and extraction of lipids from the lysate, and (4) enzymatic digestion of RNA and elimination of polysaccharides by centrifugation or digestion, followed by separation of the DNA from the digestion products by selective isopropanol precipitation This procedure yields a preparation of total-yeast DNA including all three buoyant density species observed in neutral isopycnic cesium chloride gradients: nuclear, nuclear heavy satellite, and mitochondrial If spheroplasting of the cells is adequate and lysis is complete, there are no preferential losses of any of the observed DNA species Preparations free of DNA of mitochondrial density can be obtained from petite yeast strains that lack mitochondrial DNA The various DNA species obtained from normal strains by this method may be separated and purified using cesium chloride gradients, cesium chloride–ethidium bromide gradients, cesium sulfate–mercury, or cesium sulfate–silver gradients, and hydroxyapatite chromatography
446 citations
TL;DR: It is suggested that inhibition of cell wall synthesis by any means triggers bacterial autolytic enzymes by destabilizing the endogenous complex of an autolysin inhibitor (lipoteichoic acid) and Autolytic enzyme.
Abstract: During penicillin treatment of an autolysin defective mutant pneumococcus we have observed three novel phenomena: (i) Growth of the mutant cultures is inhibited by the same concentrations of penicillin that induce lysis in the wild type. (ii) Mutant bacteria treated with the minimum growth inhibitory concentration of penicillin will lyse upon the addition of wild-type autolysin to the growth medium. Chloramphenicol and other inhibitors of protein synthesis protect the cells against lysis by exogenous enzyme. Sensitivity of the cells to exogenous autolysin requires treatment with penicillin or other inhibitors of cell wall synthesis (e.g., D-cycloserine or fosfonomycin) since exogenous autolysin alone has no effect on bacterial growth. (iii) Treatment with penicillin (or other inhibitors of cell wall synthesis) causes the escape into the medium of a choline-containing macromolecule that has properties suggesting that it contains pneumococcal lipoteichoic acid (Forssman antigen). Each one of these three phenomena (growth inhibition, sensitization to exogenous autolysin, and leakage of lipoteichoic acid) shows the same dose response as that of the penicillin-induced lysis of wild-type pneumococci. On the basis of these findings we propose a new hypothesis for the mechanism of penicillin-induced lysis of bacteria. It is suggested that inhibition of cell wall synthesis by any means triggers bacterial autolytic enzymes by destabilizing the endogenous complex of an autolysin inhibitor (lipoteichoic acid) and autolytic enzyme. Escape of lipoteichoic acid-like material to the growth medium is a consequence of this labilization. Chloramphenicol protects bacteria against penicillin-induced lysis by interfering with the activity of the autolytic enzyme, rather than by depleting the concentration of the enzyme at the cell surface.
215 citations
TL;DR: The results confirm the previous hypothesis that the chitin synthetase zymogen is associated with the plasma membrane, a basic assumption for the explanation of localized activation of the enzyme and initiation of septum formation.
Abstract: Pretreatment of yeast protoplasts with concanavalin A, according to the method used by G. A. Scarborough for Neurospora (J. Biol. Chem. 250, 1106-1111, 1975), reinforced the plasma membranes, and helped to maintain their integrity during subsequent lysis of the protoplasts. After purification by centrifuging on a Renografin density gradient, practically intact membranes were obtained. Previous labeling of the protoplasts with 125I or with [3H]concanavalin A resulted in recovery of the radioactivity in the membrane fraction. The bulk of the chitin synthetase (chitin synthase; UDP-2-acetamido-2-deoxy-D-glucose:chitin 4-beta-acetamidodeoxyglucosyltransferase; EC 2.4.1.16) recovered in the gradient was also found In this fraction; in the zymogen form. About 20% of the activity sedimented in a plasma-membrane-free fraction at lower density. Glutaraldehyde inactivated chitin synthetase when it was added to a lysate, but not when applied to intact protoplasts. It is concluded that chitin synthetase is so oriented in the membrane that it is only accessible from the inside of the cell. These results confirm our previous hypothesis that the chitin synthetase zymogen is associated with the plasma membrane, a basic assumption for the explanation of localized activation of the enzyme and initiation of septum formation.
208 citations
TL;DR: Using scanning electron microscopy it was possible to correlate surface alterations with exposure concentrations and cell viabilities so as to suggest a mode and sequence of cell injury which may ultimately lead to cell death.
182 citations
TL;DR: Direct evidence obtained at the single cell level shows that a single effector lymphocyte is required and sufficient for the destruction of a single target cell and that killer cells which have been responsible for the lysis of a given target cell can lyse a second and even a third time.
Abstract: Isolation and characterization of individual functionally reactive cytotoxic T lymphocytes have been achieved. Peritoneal exudate cytotoxic lymphocytes were obtained from BALB/c mice injected with EL4 tumor cells. Lymphocyte tumor cell conjugation was promoted by centrifugation. Individual conjugates comprised of one lymphocyte bound to one tumor cell were isolated with a micropipette. The ultrastructure of isolated killer lymphocytes and the lysis of conjugated target cells were analyzed. The cytotoxic lymphocytes are small cells with an indented nucleus which is poor in peripheral chromatin and rich in rough nuclear sap. The cytoplasm contains one-membrane-bound lysosome-like granules and clusters of ribosomes, but no rough endoplasmatic reticulum. The Golgi apparatus is well developed. Direct evidence obtained at the single cell level shows that a single effector lymphocyte is required and sufficient for the destruction of a single target cell and that killer cells which have been responsible for the lysis of a given target cell can lyse a second and even a third time.
164 citations
TL;DR: The time course reaction of TNBS with intact erythrocytes over a 24-hr period at 23 °C is complex and shows transition zones for both membrane phosphatidylethanolamine (PE) and membrane proteins, which indicate that these amino phospholipids are asymmetrically arranged.
Abstract: Trinitrobenzenesulfonate (TNBS), fluorodinitrobenzene (FDNB) and suberimidate have been reacted with intact human erythrocytes. TNBS does not penetrate the cell membrane significantly at 23 °C in bicarbonate-NaCl buffer, pH 8.6, as estimated by the labeling of the N-terminal valine of hemoglobin. Hence, under these conditions it can be used as a vectorial probe. However, at 37 °C, especially in phosphate buffer, at pH 8.6, TNBS does penetrate the cell membrane. FDNB and suberimidate both penetrate the erythrocyte membrane. The time course reaction of TNBS with intact erythrocytes over a 24-hr period at 23 °C is complex and shows transition zones for both membrane phosphatidylethanolamine (PE) and membrane proteins. No significant cell lysis occurs up to 10 hr. The fraction of total PE or phosphatidylserine (PS) which reacts with TNBS by this time period can be considered to be located on the outer surface of the cell membrane. Under these conditions it can be shown that 10 to 20% of the total PE and no PS is located on the outer surface of the membrane and hence these amino phospholipids are asymmetrically arranged. The pH gradient between the inside and outside of the cell in our system is 0.4 pH units. Nigericin has no effect on the extent of labeling of PE or PS by TNBS. Isotonic sucrose gives a slight enhancement of the labeling of PE by TNBS. Hence, the inability of PE and PS to react with the TNBS is considered not due to the inside of the cell having a lower pH. The extent of reaction of TNBS with PE is not influenced by changing the osmolarity of the medium or by treatment of cells with pronase, trypsin, phospholipase A or phospholipase D. However, bovine serum albumin (BSA) does protect some of the PE molecules from reacting with TNBS.
162 citations
TL;DR: The mechanism by which culture forms of Trypanosoma cruzi are lysed by normal mammalian sera was examined and the selective lysis by serum was exploited to purify viable trypomastigotes by means of centrifugation in an albumin column.
Abstract: The mechanism by which culture forms of Trypanosoma cruzi are lysed by normal mammalian sera was examined. Lysis is restricted to the epimastigote form of the organism and is not dependent on the presence of agglutinins. Lysis is a complement-dependent process, the activity being generated by the alternate pathway. The selective lysis by serum was exploited to purify viable trypomastigotes by means of centrifugation in an albumin column. Essentially pure trypomastigote populations are now being employed in cell culture experiments.
150 citations
TL;DR: The isolation and characterization of plasma membranes from a cell wall-less mutant of Neurospora crassa are described and the isolated plasma membrane vesicles have a characteristically high sterol to phospholipid ratio, Mg2+-dependent ATPase activity and (Na+ plus K+)-stimulated Mg 2+ATPase activity.
145 citations
Journal Article•
TL;DR: In this article, suspension in 10% dextran was used to interrupt the ongoing formation of adhesions between CTL and target cells already in contact in a centrifuged pellet.
Abstract: Addition of high molecular weight dextran to culture medium prevents the initiation of T lymphocyte-mediated killing by holding the cytolytic T lymphocytes (CTL) and target cells in suspension and preventing intercellular contact. Suspension in 10% dextran was used to interrupt the ongoing formation of adhesions between CTL and target cells already in contact in a centrifuged pellet. The results demonstrate that 1) firm adhesions form between CTL and target cells within 1 min at 37°C; 2) once formed, these adhesions are stable at low temperature and are resistant to mechanical shearing forces; 3) these adhesions can be disrupted by EDTA; 4) immediately after the adhesions form, separation of the CTL from the target cells prevents lysis of the latter; 5) after incubation of targets adhering to CTL for an additional 6 min at 37°C, removal of the CTL no longer prevents target cell lysis. Thus, target cells become “programmed” for subsequent lysis within a few minutes after contact with CTL, after which lysis occurs during the next several hours without further participation of the effector cell. At 15°C, adhesions form 1/17 as fast as at 37°C. Programming of target cells for lysis occurs 1/76 as fast at 15°C as at 37°C. Thus, the programming for lysis step is about 4-fold more temperature dependent than the adhesion step. In addition to being detected by subsequent target cell lysis in 10% dextran, the adhering cell clusters can be counted with low power microscopy. This permitted verification that EDTA separates the clusters after programming for lysis is complete. Moreover, the great majority of the clusters seen at 37°C are antigen-specific. Knowledge of the cluster size distribution and the subsequent level of lysis permits the deduction that not less than 6% of the sensitized peritoneal cell populations used were CTL.
TL;DR: Packaging is initiated by complexing of either monomeric or concatemeric DNA with the phage-specific A protein, the protein also responsible for the DNA cutting.
TL;DR: Two in vitro systems, one using a whole cell lysate, and the other a suspension of washed nuclei prepared from a human lymphocyte line, are characterized with respect to their requirements for the synthesis of DNA and to the nature of the synthetic product.
TL;DR: A procedure for the lysis of bacterial cells for the subsequent measurement of β-galactosidase is presented, which is more reliable, reproducible, and yields higher values of enzymatic activity than do some of the techniques espoused in the literature.
TL;DR: In this article, the extent of lysis of spheroplasts and of the liberated vacuoles was studied under various conditions using alpha-glucosidase activity and soluble arginine as cytoplasmic and vacuolar markers, respectively.
Abstract: The polybasic macromolecules DEAE-dextran (diethylaminoethyl-dextran, molecular weight 500000) and poly-DL-lysine (molecular weight 30000-70000) were absorbed with a high affinity by spheroplasts of Candida utilis and subsequently, induced lysis. The extent of lysis of spheroplasts and of the liberated vacuoles was studied under various conditions using alpha-glucosidase activity and soluble arginine as cytoplasmic and vacuolar markers, respectively. Adsorption of polybases was rapidly completed even at 0 degrees C; however, with small doses, lysis was poor at 0-12 degrees C and extensive at temperatures above 12 degrees C. This permitted the completion of adsorption before initiating lysis. The purified vacuoles were also sensitive to polybases though less so than the spheroplasts; however, after lysis of spheroplasts the liberated vacuoles were well protected against the action of polybases. A treatment with polybases which disrupted more than 99% of the spheroplasts left at least 70% of the vacuoles intact. Potassium chloride in high concentrations and calcium chloride in low concentrations inhibited polybase induced lysis of spheroplasts by preventing or even reversing the polybase adsorption. A polyacidic macromolecule, dextran sulfate, could prevent but not reverse the adsorption of polybase and subsequent lysis. Metabolic inhibitors reduced the susceptibility of spheroplasts to polybase induced lysis. Vacuoles isolated from polybase lysed spheroplasts still contained large pools of soluble amino acids, and their ability to transport arginine specifically is a further indication of their functional integrity.
TL;DR: While most membrane proteins are associated with the fluid portion of the bilayer, some proteins evidently associate preferentially with phospholipids in the gel or frozen state.
TL;DR: The choline-containing teichoic acids of pneumococci can be modified by biosynthetic replacement of the choline residues with certain structural analogues, such as ethanolamine (EA) or the N-monomethyl- (MEA) and N-dimethyl- (DEA) amino derivatives of ethanolamine as discussed by the authors.
Abstract: The choline-containing teichoic acids of pneumococci can be modified by biosynthetic replacement of the choline residues with certain structural analogues, such as ethanolamine (EA) or the N-monomethyl- (MEA) and N-dimethyl- (DEA) amino derivatives of ethanolamine. Cells containing such analogues in their teichoic acids develop pleiomorphic alterations in several physiological properties, which include resistance to detergent-induced lysis and inhibition of cell separation (chain formation). We report here the results of physiological studies on the mechanism of these two phenomena. Our results are summarized in the following: (a) Pneumococci grown on various amino alcohols produce cell walls of identical amino sugar and amino acid composition. (b) Both choline- and EA-containing teichoic acids seem to follow the same conservative pattern of segregation during growth and cell division. (c) Lysis sensitivity of pneumococci requires the juxtaposition of lysissensitive (choline-containing) cell walls and endogenous autolysin at the cell wall growth zone. (d) Upon readdition of choline to ethanolamine-containing cells, lysis sensitivity and catalytically active (C-type) autolysin reappear in the bacteria with the same kinetics. (e) The chains of EA-grown pneumococci contain fully compartmentalized cells and normal cross walls.
TL;DR: A strain of Bacillus sp (Bacillus R-4) produces a protease and a carbohydrolase both of which have the ability to lyse Rhizopus cell walls, which has been purified to an ultracentrifugally and electrophoretically homogeneous state, and identified as a chitosanase.
Journal Article•
TL;DR: Monolayers of P815 cells treated for 10 sec with 0.15% glutaraldehyde, were capable of specifically depleting T-effector cells from a cytolytically-active spleen cell population, however, the monolayers lost their capacity to adsorb effector cells.
Abstract: Mastocytoma cells (P815 of the DBA/2 strain) treated with increasing concentrations of glutaraldehyde were concurrently evaluated for their ability to incorporate exogeneous uridine, thymidine, and amino acids. The antigenic expression and membrane integrity of these treated cells were assayed by measuring their susceptibility to lysis by antibody and complement and by T-effector cells. The concentrations of glutarladehyde required to effect target cell antigen display were greater than those required to inhibit totally the cell's protein and nucleic acid synthetic processes. Thus, P815 cells treated with 0.15% glutaraldehyde for 10 sec were unable to incorporate either amino acids or nucleotides into macromolecules, but were readily lysed by effector T cell populations, and by alloantibody in the presence of complement. Target cells treated with glutaraldehyde concentrations in excess of 0.25% for 10 sec were resistant to both forms of immune lysis. In keeping with these observations, monolayers of P815 cells treated for 10 sec with 0.15% glutaraldehyde, were capable of specifically depleting T-effector cells from a cytolytically-active spleen cell population. After treatment with higher concentrations of glutaraldehyde (0.3%), however, the monolayers lost their capacity to adsorb effector cells. Although P815 cells treated with glutaraldehyde continued to exhibit H-2d alloantigen, neither these cells nor glutaraldehyde-treated DBA/2 spleen cells induced significant blastogenesis or stimulated the production of cytolytically active effector cells in mixed leukocyte cultures.
TL;DR: The authors' data suggest that the terminal complement complex associates with membrane "core" components through apolar interactions, and is likely to be eluted by any of the described methods or combination of methods.
TL;DR: The dissociation of Semliki Forest virus induced by increasing concentrations of the anionic detergent sodium dodecyl sulfate was studied using density gradient centrifugation and found that the extent of virus dissociation could be controlled both by the detergent concentration and by the temperature.
Abstract: The dissociation of Semliki Forest virus induced by increasing concentrations of the anionic detergent sodium dodecyl sulfate was studied using density gradient centrifugation. Detectable binding to the virus started well below the critical micellar concentration of the detergent and increased thereafter with increased detergent concentration. At 4 degrees there were about 11,000 binding sites per virus particle with an average association constant of about 10-5 M-1. The extent of virus dissociation could be controlled both by the detergent concentration and by the temperature. At 4 degrees only disruption ("lysis") of the virus membrane could be observed. At 20 degrees most of the membrane was solubilized into lipoprotein complexes, and the nucleocapsid dissociated into RNA and protein. Complete delipidation of the viral membrane proteins was achieved at 30 degrees at a detergent concentration still below the critical micellar concentration.
TL;DR: A difference in the organization of adenylate cyclase and 3′5′-cyclic phosphodiesterase in isolated plasma membranes was observed by the development of a new technique for the lysis of Dictyostelium discoideum using the polyene antibiotic amphotericin B.
TL;DR: The reconstituted system, made by adding back the cytoplasmic fraction before incubation at 30 degrees, completely restored the in vitro level of SV40(I) DNA synthesis.
TL;DR: Results indicate that tropolone acts on the cell wall or envelope and on the plasma membrane and that bacteriostatic and bactericidal activity was quantitated using standard methods.
Abstract: Tropolone was shown to be bacteriostatic and bactericidal for a wide range of bacterial species. This antibacterial activity was quantitated using standard methods. Tropolone treatment of whole cells resulted in cell lysis characterized by bleb formation and subsequent loss of cell contents after rupture of the bleb. Although bleb formation and lysis did not occur in the presence of 20% sucrose, cell viability was lost. Spheroplasts and protoplasts also lysed in the presence of tropolone. These results indicate that tropolone acts on the cell wall or envelope and on the plasma membrane.
TL;DR: Pneumococcal lipoteichoic acid (Forssman antigen) added to the medium of growing pneumococcal cultures caused chain formation, prevented culture lysis in the stationary phase of growth, and inhibited lysis by penicillin and by the pneumococCal bacteriophage Dp-1.
Abstract: Pneumococcal lipoteichoic acid (Forssman antigen) added to the medium of growing pneumococcal cultures caused chain formation, prevented culture lysis in the stationary phase of growth, and inhibited lysis by penicillin and by the pneumococcal bacteriophage Dp-1.
TL;DR: The addition of ethylenediaminetetraacetate to sheep erythrocytes preincubated with sphingomyelinase C was found to induce rapid hemolysis at 37 C, and the data suggest that exogenously added and/or membrane-bound divalent cations are important for the stability of sphingomelin-depleted membranes.
Abstract: Staphylococcus aureus produces a phospholipase C specific for sphingomyelin (beta-hemolysin). Erythrocytes with approximately 50% sphingomyelin in their membranes, e.g., from sheep, have been shown to have up to 60% of this phospholipid hydrolyzed by this enzyme at 37 C in isotonic buffered saline without hemolysis. Cooling of sphingomyelinase C-treated erythrocytes to 4 C causes complete lysis of the cells, a phenomenon known as hot-cold hemolysis. The addition of ethylenediaminetetraacetate (EDTA) to sheep erythrocytes preincubated with sphingomyelinase C was found to induce rapid hemolysis at 37 C. The treated cells became susceptible to chelator-induced hemolysis and to hot-cold hemolysis simultaneously, and the degree of lysis of both mechanisms increased equally with prolonged preincubation with sphingomyelinase C. Erythrocytes of species not readily susceptible to hot-cold hemolysis were equally insusceptible to chelator-induced lysis. Chelators of the EDTA series were the most effective, whereas chelators more specific for Ca2+, Zn2+, Fe2+, Cu2+, and Mg2+ were without effect. The rate of chelator-induced lysis was dependent on the preincubation period with beta-hemolysin and on the concentration of chelator added. The optimal concentration of EDTA was found to equal the amount of exogenously added Mg2+, a cation necessary for sphingomyelinase C activity. Hypotonicity increased the rate of chelator-induced hemolysis, whereas increasing the osmotic pressure to twice isotonic completely inhibited chelator-induced lysis. The data suggest that exogenously added and/or membrane-bound divalent cations are important for the stability of sphingomyelin-depleted membranes. The phenomenon of hot-cold hemolysis may be a consequence of the temperature dependence of divalent ion stabilization.
TL;DR: The results obtained indicate that the capacity of Mg-2+ salts at very low concentration to prevent lysis of intact cells and mureinoplasts of this organism is due primarily to the interaction of Mm-2- with the peptidoglycan layer of the cell wall.
Abstract: Intact cells of marine pseudomonad B-16 (ATCC 19855) which have been washed with a solution of NaCl require only 0.001 M MgSO4 and 100 to 300 times this concentration of NaCl or KCl to prevent lysis. Conversion of intact cells to mureinoplasts, a process involving removal of the outer double-track layer (outer membrane) and the periplasmic space layer of the cell wall, approximately doubled the requirement for the three salts to prevent lysis. The formation of protoplasts from mureinoplasts by removing the peptidoglycan layer again doubled the requirement for Na+ and K+ salts but increased the requirement for the Mg-2+ salt 200- to 300-fold. Cells of the marine pseudomonad suspended in solutions containing Mg-2+ salts failed to lyse on subsequent repeated suspension in distilled water, whereas cells presuspended in NaCl lysed immediately. Isolated envelope layers including the peptidoglycan layer, when dialyzed against solutiions containing Mg-2+ salts, retained Mg-2+ after subsequent suspension in distilled water. Envelope layers exposed to solutions of Na+ or K+ salts failed to retain these ions after exposure to distilled water. Na+ displaced Mg-2+ from the cell envelope layers. The results obtained indicate that the capacity of Mg-2+ salts at very low concentration to prevent lysis of intact cells and mureinoplasts of this organism is due primarily to the interaction of Mg-2+ with the peptidoglycan layer of the cell wall. Ion interaction with the layers lying outside of the peptidoglycan layer contributes only a small amount to the mechanical strength of the wall.
TL;DR: Both Cu++ and Zn++ inhibited the formation of hemolytically active EC56789 from EC5678 and C9, and Cu++ is shown to inactivate irreversibly the hemolytic activity ofEC5678.
Abstract: The effect of various metal ions, Fe++, Fe+++, Cu++, Zn++, Co++, on the terminal stage of reactive lysis (a form of complement-mediated hemolysis
TL;DR: The data suggest that the employment of highly purified cationic proteins of leukocytes and tissues to study bactericidal models may not reflect the actual conditions that prevail in inflammatory exudates.
Abstract: Lysis of14C-labeledStaph. aureus by human blood leukocyte lysates, by extracts of rabbit small intestines and pancreas, and by the “cocktail” of enzymes (containing trypsin, lysolecithin, and lysozyme) is strongly inhibited by anionic polyelectrolytes (e.g., heparin, chondroitin sulfate, liquoid (polyanethole sulfonic acid), and DNA). Most of the lytic agents employed were inhibited by cationic polyelectrolytes (e.g., histone, protamin sulfate and polylysin), as well as by gold thiomalate, normal human serum, synovial fluids obtained from patients with knee-joint trauma, extracts of coffee, tea, and cocoa, Ultracorten- and Dexamethasone. On the other hand, some antiinflammatory agents tested (e.g., indomethacin, aspirin, hydrocortisone acetate and succinate, and prednisolone acetate and tributyl acetate) were not inhibitory. All the cationic polyelectrolytes employed and liquoid were also strong inhibitors of lysozyme. Since mixtures of cationic and anionic polyelectrolytes at equimolar concentrations failed to inhibit bacteriolysis, it is postulated that the balance between charged macromolecular substances, which are likely to accumulate in inflammatory foci, may determine the fate of cellular components of bacteria in inflamed tissues. The possible role played by lysosomal enzymes and by tissue inhibitors in tissue damage and in the survival of bacteria in chronic inflammatory lesions is discussed.
TL;DR: The degree of single strandedness of the DNA released from rat liver nuclei by various alkaline lysing solutions was determined both before and after sedimentation in alkaline sucrose gradients employing electron microscopy, melting profiles, circular dichroism measurements, and digestibility by S1 nuclease.