| transport properties of membrane vesicles from acholeplasma laidlawii. ii. kinetic characteristics and specificity of glucose transport system. | the glucose transport system of membrane vesicles isolated from acholeplasma laidlawii is saturable, with a km of 21.2 mum and v of 0.68 nmol min-1 (mg protein)-1. the process is ph-dependent and a break occurs in the arrhenius plot at 15 degrees c. exogenous substrates did not stimulate glucose transport probably due to their inability to penetrate into membrane vesicles. 3-o-methylglucose and 6-deoxyglucose competitively inhibited glucose transport. maltose inhibited transport of glucose nonco ... | 1975 | 286 |
| properties of the 3-o-methyl-d-glucose transport system in acholeplasma laidlawii. | transport of 3-o-methyl-d-glucose (3-o-mg) by acholeplasma laidlawii cells was studied. the 3-o-mg transport system appeared to be constitutive in cells grown on 3-o-mg and glucose; the transport process depended on the concentration of substrate used and exhibited typical saturation kinetics, with an apparent km of 4.6 mum. 3-o-mg was transported as a free carbohydrate and was not metabolized further in the cell. dependence on ph and temperature and the results of efflux and "counterflow" exper ... | 1976 | 1368 |
| variation in distribution of membrane particles in acholeplasma laidlawii b with ph. | | 1976 | 4629 |
| surface balance study of the interaction between microorganisms and lipid monolayer at the air/water interface. | using the surface balance technique, we have compared the interaction between acholeplasma laidlawii and some marine bacteria towards different types of monolayered lipid films. cells from a. laidlawii and serratia marinorubra penetrate the film, whereas cells from psuedomonas fluorescens form a layer underneath the film. the forces that bind microorganisms to the air/water interface are not strong enough to scatter a condensed monolayer but increase the strength of loosely packed monolayers. | 1976 | 5058 |
| cultivation of mycoplasmas in a modified tissue culture medium. | a new medium, which contained a chemically defined tissue culture base ("medium 199"), was developed for the cultivation of mycoplasmas. when supplemented with albumin, glucose, serum, and yeast extract, the new medium adequately supported the growth of mycoplasma and acholeplasma species. | 1976 | 7199 |
| differential reaction of cell membrane phospholipids and proteins with chemical probes. | the major aims of this study were to determine the degree of phospholipid asymmetry and the neighbor analysis of phospholipids in different types of cell membranes. for this study a penetrating probe (fdnb), a non-penetrating probe (tnbs) and a cross-linking probe (dfdnb) were used. the reaction of hemoglobin, membrane protein and membrane pe and ps of erythrocytes with dfnb and tnbs was studied over a concentration range of 0.5 to 10 mm probe. tnbs reacts to an extremely small extend with hemog ... | 1976 | 7364 |
| detection of serum proteins in the electrophoretic patterns of total proteins of mycoplasma cells. | the contamination of mycoplasma cell preparations by serum proteins originating from culture medium was studied. a. laidlawii and m. arthritidis cells were grown in the presence of 14c-aminoacids, and the cells were washed with 0-9% nac1 by threefold centrifugation. total proteins of the washed cells were analysed by sds gel electrophoresis. coomassie-stained electrophoretic patterns were compared with autoradiographs of the same gels. the stained electrophoretic pattern of washed a. laidlawii g ... | 1976 | 10333 |
| reduced nicotinamide adenine dinucleotide oxidase activity in membranes and cytoplasm of acholeplasma laidlawii and mycoplasma mycoides subsp. capri. | the properties of the membrane-bound reduced nicotinamide adenine dinucleotide (nadh) oxidase of acholeplasma laidlawii were compared with those of the corresponding cytoplasmic activity of mycoplasma mycoides subsp. capri. the striking differences in ph optima, susceptibility to inhibitors and detergents, and heat inactivation between the nadh oxidase activity, with oxygen as an electron acceptor, and the nadh oxidoreductase activity, with dichlorophenol indophenol (dcpip) as an alternate elect ... | 1976 | 11208 |
| microcalorimetric detection of growth of mycoplasmatales. | a static ampoule microcalorimeter was used to study the growth of mycoplasmas, acholeplasmas and ureaplasmas. growth as indicated by thermograms was compared with the results of conventional methods, namely, terminal dilution counts, plate counts, turbidimetric measurements, glucose consumption and ph changes. removal of oxygen had little effect on mycoplasma growth. the microcalorimetric method is potentially useful for identifying and enumerating the members of the mycoplasmatales. | 1976 | 11273 |
| membrane-bound thioesterase activity in mycoplasmas. | thioesterase activity was found in all mycoplasmas tested. activity was highest in acholeplasma species, whereas most of the sterol-requiring mycoplasma species showed little activity. the thioesterase activity of acholoplasma laidlawii is confined to the cell membrane. the enzyme could not be released from the membrane by either low- or high-ionic-strength solutions, with or without ethylenediaminetetraacetic acid, nor solubilized by detergents. the enzyme has a general specificity for long-cha ... | 1977 | 14108 |
| localization of enzymes in ureaplasma urealyticum (t-strain mycoplasma). | ureaplasma urealyticum cells were lysed by osmotic shock or by digitonin. the membrane fraction contained four to ten times as much protein as the cytoplasmic fraction. these values are in large excess of those reported for classical mycoplasmas, suggesting that the ureaplasma membrane fraction was heavily contaminated with proteins derived from the growth medium. the u. urealyticum urease activity was localized in the cytoplasmic fraction, whereas the adenosine triphosphatase activity was local ... | 1977 | 15980 |
| fractionation of membrane proteins by hydrophobic interaction chromatography and by chromatography on agarose equilibrated with a water-alcohol mixture of low or high ph. | | 1978 | 25906 |
| symport h+/carbohydrate transport into acholeplasma laidlawii cells. | | 1978 | 26600 |
| effect of ammonium ion concentration and osmotic pressure on growth of ureaplasma urealyticum (t-strain mycoplasma). | the effect of ammonium ion concentration and osmotic pressure on growth of ureaplasma urealyticum type viii was determined by using a well-buffered broth medium containing 10 mm urea. the addition of nh4cl to the medium at concentrations up to 10 mm did not affect growth; however, addition of larger quantities progressively decreased both the specific growth rate (mu) and the maximum yield of the culture, with concentrations of 80 mm completely inhibiting growth. addition of either 150 mm kcl or ... | 1978 | 26668 |
| physiological role and membrane lipid modulation of the membrane-bound (mg2+, na+)-adenosine triphosphatase activity in acholeplasma laidlawii. | the membrane-bound adenosine triphosphatase (atpase) activity of acholeplasma laidlawii b differs in many respects from the common (mg2+, ca2+)-atpase activity of higher bacteria, most notably in that it is specifically activated by mg2+ and strongly and specifically stimulated by na+ (or li+). various inhibitors diminish the atpase activity with a concentration dependence which suggests that a single enzyme species is responsible for all of the observed atp hydrolytic activity (both basal and n ... | 1978 | 31351 |
| [glucose induced transport of h+, k+ and lactate in the cells of acholeplasma laidlawii]. | currents of h+ and k+ ions initiated under the effect of facultative anaerobe of a. laidlawii, valinomycin, nigericin and carbonyl cyanide chloride phenylhydrasone on the membrane are recorded by means of the system of cation sensitive electrodes. it is stated that during glucose transport a redistribution of h+ and k+ and lactate between the cellular content and the medium takes place. preincubation of cells with 3-o-methyl-d-glucose essentially decreases the effect of induced ion transport. it ... | 1979 | 35239 |
| size and shape of mycoplasma virus mv-lg-l 172 dna. | sedimentation of dna of mycoplasma virus mv-lg-l 172 in neutral and alkaline density gradients showed that the chromosome of this virus is most probably formed by a double-stranded circular dna molecule with a molecular weight of approx. 10(7) daltons. these results were confirmed by direct electron microscopy of the viral dna. gamma-irradiation of the virus caused in its dna single breaks on the average per each 66 ev of absorbed energy. virus survival depended exponentially on the irradiation ... | 1978 | 35941 |
| [regulatory mechanisms of membrane lipids--with reference to environmental adaptation (author's transl)]. | | 1979 | 41021 |
| the pathogenicity of avian mycoplasmas. | based on literature data and own experiences the author gives an outlook about pathogenicity of avian mycoplasmas. in chickens and turkeys m. gallisepticum and m. synoviae (in addition to it m. meleagridis exclusively in turkeys) are the most important mycoplasmas producing respiratory disease, inflamation of synovial membranes and other lesions. their pathogenic effect is very much influenced by dose of agent, route of entry of microorganism, age of birds, virulence and tropism of organism as w ... | 1979 | 44612 |
| pathogenicity of mycoplasmas for arthropods. | | 1979 | 44614 |
| [bidimensional immunoelectrophoretic study of the antigenic composition of the membrane in various mycoplasma strains]. | membrane antigenic composition of acheloplasma laidlawii pg9, a. granularum bts-39, and mycoplasma fermentans pg 18(g) was determined by means of bidimensional immunoelectrophoresis in the presence of sodium desoxycholate 0.5%. depending upon the mycoplasma species from which membranes were obtained, 7 to 15 antigens were evidenced. using sodium desoxycholate presents the advantage over non-ionic detergents to dissolve better the mycoplasmic membrane antigenic complexes. a comparative study of f ... | 1976 | 61061 |
| complement-mediated killing of acholeplasma laidlawii by antibodies to various membrane components. | mycoplasmas are useful models for biochemical studies of the mechanism of complement-mediated killing by antibodies to various membrane components. the purpose of this study was to determine the membrane antigens involved in immune killing of acholeplasma laidlawii. antibodies to a. laidlawii membrane total lipids, glycolipids, and phospholipids could be induced in rabbits after injection of reaggregates of the purified lipids with mycoplasma hominis protein as the carrier. killing of a. laidlaw ... | 1976 | 61175 |
| keratitis and acholeplasma laidlawi. | | 1976 | 61420 |
| ultrastructural and cytochemical studies on anionic surface sites of mycoplasma membranes. | negatively charged, chemical groups on the surfaces of mycoplasma membranes were studied in the electron microscope by staining with positively charged ferric oxide hydrosols in the acetic acid (ai-reagent) or propanoic acid (pi-reagent), respectively. the technique of thin sectioning was used. with the ai-reagent, no significant binding of the ferric oxide particles was observed on the mycoplasma membranes. with the lipophilic pi-reagent, the membrane surfaces of m. mycoides subsp. capri, m. my ... | 1977 | 65876 |
| homogeneity of lipopolysaccharides from acholeplasma. | five methods were employed to determine the heterogeneity or homogeneity of lipopolysaccharides from four acholeplasmal species, acholeplasma axanthum, a. granularum, a. laidlawii, and a. modicum. a axanthum lipopolysaccharide behaved as a single component in all tests. a. granularum exhibited two components of identical composition and antigenic specificity. a. modicum lipopolysaccharide behaved as three components in two tests, but all three were similar in composition and identical serologica ... | 1977 | 67111 |
| effect of various culturing conditions of acholeplasma laidlawii on the yield and properties of the cells and cell membrane. | acholeplasma laidlawii strain b cell cultured in complex medium have an optimal temperature of growth at 31 degrees. maximal growth at this temperature is 80% higher than at 37 degrees. by stirring of the culture, the yield of the cell mass of 4 liter-cultures increases by 200%. with these modifications the yield of cell membranes increases 3--4 times with respect to that of static culturing at 37 degrees. membranes obtained from better aerated cultures have a lower flavin and carotenoid content ... | 1977 | 67754 |
| demonstration by electron microscopy of intracellular virus in acholeplasma laidlawii infected with either mv-l3 or a similar but serologically distinct virus (bn1 virus). | cultures of acholeplasma laidlawii strain m1305/68 were inoculated with mycoplasmatales virus-laidlawii 3 (mv-l3) and examined by electron microscopy. particles resembling mv-l3 were observed both intra- and extracellularly in thin sections prepared from mv-l3 infected cultures, but not from uninfected cultures. similar particles were occasionally observed in uninoculated cultures of a. laidlawii strain bn1 cells, from which a virus (bn1 virus) was subsequently isolated. this virus was morpholog ... | 1979 | 84856 |
| mycoplasma contamination in cell culture of crohn's disease material. | | 1979 | 89521 |
| role of cholesterol in the action of cereolysin on membranes. | | 1978 | 102256 |
| the nature and location of acholeplasma laidlawii membrane proteins investigated by two-dimensional gel electrophoresis. | the high resolution, two-dimensional electrophoresis system for the separation of proteins described by o'farrell, (o'farrell, p.h. (1975) j. biol. chem. 250, 4007--4021) has been modified for the separation of acholeplasma laidlawii proteins. reproducible protein patterns have been obtained from a. laidlawii cell, membrane and soluble protein preparations. the isoelectric focusing of membrane proteins was greatly improved by removing the bulk of the membrane lipid before solubilizing the protei ... | 1978 | 102346 |
| in vitro antimycoplasmal activity of mepartricin. | the in vitro antimycoplasmal activity of mepartricin was evaluated on several mycoplasma strains. the results demonstrate that this polyene antibiotic possesses a high efficacy against these microorganisms. | 1979 | 118890 |
| gliding mycoplasmas are inhibited by cytochalasin b and contain a polymerizable protein fraction. | studies are presented on the effect of cytochalasin b (cb) on the growth of five mycoplasma species, three acholeplasma species, and one spiroplasma species. the three gliding mycoplasma species (m gallisepticum, m pneumoniae and m pulmonis are the only mycoplasmas inhibited by cb. these are the only prokaryotes reported to be inhibited by cb. this suggested that these three mycoplasmas might have some sort of cytoskeletal structure. a protein fraction has been isolated from m gallisepticum whic ... | 1979 | 121144 |
| transport properties of membrane vesicles from acholeplasma laidlawii. i. isolation and general characteristics. | a new procedure for the isolation of membrane vesicles from acholeplasma laidlawii cells is described. the membrane vesicles are completely free from contaminations of whole cells and cell debris and represent a homogeneous fraction as shown by electron microscopy, ficoll density-gradient centrifugation, and titration on agar plate. absence of cytoplasmic contaminations was confirmed by double-labelling of membranes with 3h-oleic acid and 14c-uridine, as well as by distribution of specific marke ... | 1975 | 127739 |
| antibiotics for elimination of mycoplasmas and ureaplasma from bovine semen. | minocin at 500 micrograms/ml of semen extender eliminated ureaplasma from naturally or artificially infected bovine semen. minocin with lincospectin eliminated acholeplasma laidlawii, mycoplasma bovigenitalium, bovis, canadense, and arginini from artificially infected semen. stabilization times of 15 min at 35 c and 3 h at 4 c are important considerations to maximize antibiotic activity. | 1977 | 141466 |
| carbohydrate content and enzymic activites in the membrane of spiroplasma citri. | | 1977 | 142817 |
| membrane enzymes: artifacts in arrhenius plots due to temperature dependence of substrate-binding affinity. | for the membrane sodium-stimulated magnesium-adenosinetriphosphatase of acholeplasma laidlawii b both the vmax and km values in the michaelis equation very strongly with temperature. simulations of arrhenius plots show that an enzyme with a temperature-dependent km can yield a variety of arrhenius plot artifacts, most notably erroneous "breaks," if activity is assayed at a fixed substrate concentration. | 1978 | 146257 |
| the effect of high hydrostatic pressure on the membrane-bound atp-ase of acholeplasma laidlawii b [proceedings]. | | 1979 | 160925 |
| [infectious keratoconjunctivitis of cattle in ivory coast. i. microbiological aspects]. | | 1975 | 174165 |
| phosphorus nuclear magnetic resonance of acholeplasma laidlawii cell membranes and derived liposomes. | 1. the 129 mhz 31p-nmr spectrum of acholeplasma laidlawii membranes is very similar to the spectrum of the derived liposomes and is a typical "solid state" spectrum in which the major contribution to the linewidth is made by the chemical shift anisotropy. from the value of the chemical shift anisotropy an order parameter of 0.15 is estimated for the lipid phosphates in both membranes. 2. the 31p-nmr spectrum of the a. laidlawii membrane is insensitive to pronase digestion of 4-60% of the membran ... | 1976 | 174728 |
| action of polymyxin b on bacterial membranes: phosphatidylglycerol- and cardiolipin-induced susceptibility to polymyxin b in acholeplasma laidlawii b. | to identify the polymyxin receptor molecules in the membranes of living microorganisms, fusion of intact acholeplasma laidlawii b with lipid vesicles was investigated according to the procedure of grant and mcconnell (1973). the naturally polymyxin-resistant a. laidlawii b was treated with phospholipid vesicles prepared from purified phospholipids of the polymyxin-susceptible salmonella typhimurium g30. a. laidlawii b absorbed between 15 and 45% of its own lipid content of the added tritium-labe ... | 1976 | 176930 |
| the reduced nicotinamide adenine dinucleotide "oxidase" of acholeplasma laidlawii membranes. | an nadh dehydrogenase possessing a specific activity 3-5 times that of membrane-bound enzyme was obtained by extraction of acholeplasma laidlawii membranes with 9.0% ethanol at 43 degrees c. this dehydrogenase contained only trace amounts of iron (suggesting an uncoupled respiration), a flavin ratio of 1:2 fad to fmn and 30-40% lipid. its resistance to sedimentation is probably due to the high flotation density of the lipids. it efficiently utilized ferricyanide, menadione and dichlorophenol ind ... | 1976 | 177076 |
| thermotropic transitions in biomembranes. | | 1976 | 182064 |
| structure of the mannoheptose-containing pentaglycosyldiacylglycerol from acholeplasma modicum. | | 1976 | 182247 |
| recognition of different pools of phosphatidylglycerol in intact cells and isolated membranes of acholeplasma laidlawii by phospholipase a2. | phospholipase a2 (ec 3.1.1.4) from pig pancreas hydrolyzes phosphatidylglycerol in intact cells and isolated membranes of acholeplasma laidlawii. complete degradation of phosphatidylglycerol in intact cells at 37 degrees c does not result in lysis as shown by the retention of intracellular k+ ions and the cytoplasmic glucose-6-phosphatase, as well as the inability to detect activity of membrane-bound intracellular nadh-oxidase. a. laidlawii was grown on linoleic acid. phospholipase a2 treatment ... | 1977 | 191065 |
| rapid biochemical tests for characterization of the mycoplasmatales. | methods are described for the rapid detection of beta-d-glucosidase and phosphatase in mycoplasma cultures using fluorogenic 4-methylumbelliferone substrates. these methods were applied to a selection of mycoplasma cultures and were compared with the conventionally used tests for these enzymes. results were similar by both methods, but the fluorogenic tests could be read after 1 h, whereas the conventional tests took several days. | 1977 | 194917 |
| cholesterol transfer from serum lipoproteins to mycoplasma membranes. | | 1977 | 199249 |
| [experimental infection of dogs with myocplasmas (acholeplasma laidlawii)]. | | 1977 | 202113 |
| acholeplasma laidlawii membranes: an electron spin resonance study of the influence on molecular order of fatty acid composition and cholesterol. | | 1978 | 216314 |
| purification and properties of acetate kinase from acholeplasma laidlawii. | acetate kinase (ec 2.7.2.1) was purified from acholeplasma laidlawii cytoplasm by a combination of ammonium sulfate fractionation, gel filtration, diethylaminoethyl-cellulose chromatography, and affinity chromatography on 8-(6-aminohexylamino)-adenosine 5'-triphosphate conjugated to sepharose 4b. the enzyme was composed of polypeptide chains of about 50,000 molecular weight as estimated from sodium dodecyl sulfate-polyacrylamide gel electrophoresis. under nondenaturating conditions, apparent mol ... | 1979 | 217865 |
| the ayerst award lecture 1978. organization and dynamics of membrane lipids as determined by magnetic resonance spectroscopy. | | 1979 | 218704 |
| activities of enzymes of purine and pyrimidine metabolism in nine mycoplasma species. | | 1979 | 232630 |
| characterization of the mycoplasma membrane proteins. v. release and localization of membrane-bound enzymes in acholeplasma laidlawii. | the peripheral membrane protein fraction released by washing acholeplasma laidlawii membranes with low-ionic strength buffers contained about 50% of the total membrane-bound ribonuclease and deoxyribonuclease activities. the atpase, nadh oxidase and p-nitrophenylphosphatase activities remained bound to the membrane even when edta was added to the wash fluids, and thus appear to belong to the integral membrane protein group. serving as a marker for peripheral membrane proteins, the membrane-bound ... | 1975 | 234252 |
| electron-microscopic study of a mycoplasmatales virus, strain mv-lg-ps2-l 172. | morphology and adsorption of a globular virus, lysing acholeplasma laidlawii were studied in ultrathin sections of plaques in a lawn of the host strain. the virus was globular, about 50 to 90 nm in diameter, with a clearly defined membrane, 6.5 to 8 nm thick. a protuberance about 25 to 35 nm long and 12 to 20 nm thick was observed on numerous virus particles. the evenly granulated, electron-optically dense content of the cells became clearer in cells affected by the viruses. fibrillar structures ... | 1975 | 234904 |
| differential fluorescence labelling with 5-dimethyl-aminonaphthalene-1-sulfonyl chloride of intact cells and isolated membranes in salmonella typhimurium and acholeplasma laidlawii. | for fluorescence labelling intact cells and isolated cell envelopes (membranes) from salmonella typhimurium and acholeplasma laidlawii were treated with mixed dansylchloride-lecithin-cholesterol vesicles. this kind of dansylation, which has been supposed to be specific for cell surface proteins, produced fluorescent protein pattern after sds-polyacrylamide gel electrophoresis only when isolated envelopes were dansylated. acid hydrolysis of fluorescent cell envelopes of salmonella typhimurium yie ... | 1975 | 235245 |
| [glucose transport into membrane vesicles from acholeplasma laidlawii cells]. | | 1975 | 235409 |
| purification of membrane proteins from acholeplasma laidlawii by agarose suspension electrophoresis in tween 20 and polyacrylamide and dextran gel electrophoresis in detergent-free media. | four of the membrane proteins from acholeplasma laidlawii that are soluble in the nonionic detergent tween 20 have been purified by preparative electrophoretic techniques utilizing different supporting media. the last purification step for two of the major proteins was a preparative polyacrylamide gel electrophoresis performed in the absence of any detergent. the proteins were recovered by continuous elution. the purity of the fractions was examined by analytical polyacrylamide gel electrophores ... | 1975 | 235514 |
| electron diffraction studies of biological membranes and lipids. | | 1975 | 235744 |
| [identification of mycoplasmas isolated from monkeys]. | the authors identified 15 strains of mycoplasmae isolated from papio hamadryas suffering from leukemia and from healthy macacus rhesus, a green monkey and saimiri. a study was made of their biochemical properties, antigenic properties in the reaction of growth depression with immune sera to a number of standard strains, and also the protein composition by electrophoresis in polyacrylamide gel (epag). a number of mycoplasmae were identified as a. laidlawii, m. arthritidis--campo and m. cynomolgus ... | 1975 | 235821 |
| adenine formation from adenosine by mycoplasmas: adenosine phosphorylase activity. | mammalian cells have enzymes to convert adenosine to inosine by deamination and inosine to hypoxanthine by phosphorolysis, but they do not possess the enzymes necessary to form the free base, adenine, from adenosine. mycoplasmas grown in broth or in cell cultures can produce adenine from adenosine. this activity was detected in a variety of mycoplasmatales, and the enzyme was shown to be adenosine phosphorylase. adenosine formation from adenine and ribose 1-phosphate, the reverse reaction of ade ... | 1975 | 236559 |
| immunogenetic analysis of the mechanism of induction of friend virus leukemia. | | 1975 | 236610 |
| scanning of polyacrylamide gel electrophoresis columns for detection of unstained protein zones and for their localization relative to enzyme activities. | | 1975 | 236684 |
| crossed immunoelectrophoresis: polyacrylamide gel electrophoresis followed by electrophoresis into an agarose gel containing antibodies. | | 1975 | 236696 |
| osmotic behaviour of acholeplasma laidlawii b cells with membrane lipids in liquid-crystalline and gel state. | the osmotic behaviour of acholeplasma laidlawii b cells was investigated with combined spectrophotometric and enzymatic measurements. the conclusion could be drawn that this osmotic behaviour depends largely on the physical state of the membrane lipids. when part of the membrane lipids is in the liquid-crystalline phase the cell is able to swell and behaves as a good osmometer. however, when the membrane lipid is in the gel phase, the cell is unable to swell and the change in absorbance of the c ... | 1975 | 236790 |
| glucose transport in acholeplasma laidlawii b: dependence on the fluidity and physical state of membrane lipids. | the uptake of d-glucose by acholeplasma laidlawii b occurs via a mediated transport process, as shown by the following observations: (i) glucose permeates a. laidlawii b cells at a rate at least 100 times greater than would be expected if its entry occurred only by simple passive diffusion; (ii) the apparent activation energy for glucose uptake in a. laidlawii is significantly lower than that expected and observed for the passive permeation of this sugar; (iii) glucose uptake appears to be a sat ... | 1975 | 237881 |
| heterogeneity in the physical state of the exterior and interior regions of mycoplasma membrane lipids. | | 1975 | 238513 |
| membrane lipid, not polarized water, is responsible for the semipermeable properties of living cells. | it has recently been proposed that the semipermeable surface barrier of living cells is in fact provided by water polarized in multilayers by the cellular protein, and not by the lipids of the cell membrane as had been widely supposed. this review paper summarizes a large and diverse body of recent experimental work, concerned with the structure and function of biological membranes in general and with the passive permeability properties of cell surface membranes in particular, which does not sup ... | 1975 | 238671 |
| determination of membrane properties at the molecular level by carbon-13 and deuterium magnetic resonance. | | 1978 | 279301 |
| ultrastructural localization of tellurite reduction in acholeplasma species. | aerobic reduction of tellurite by five acholeplasma species and two mycoplasma species was investigated by light and electron microscopy. among the acholeplasma species, colonies of a. laidlawii and a. oculi exhibited a heavy, macroscopically visible reduction of tellurite, whereas the reaction of a. axanthum was weaker. a. granularum and a. modicum did not reduce the substrate under the experimental conditions employed. the two subspecies of m. mycoides also reacted with tellurite, as did also ... | 1977 | 329638 |
| localization of a phosphoglycolipid in mycoplasma membranes using specific anti-lipid-antibodies. | a phosphoglycolipid, presumably identical to glyceryl-phosphoryldiglycosyl diglyceride, is the main component of the membrane glycolipids of mycoplasma mycoides subsp. capri. it is immunologically active. anti-phosphoglycolipid antibodies were induced in rabbits by intravenous injection of the flocculated complexes of methylated bovine serum albumin with a mixture of the phosphoglycolipid and the auxiliary lipids, phosphatidyl-choline and cholesterol. the specificities of the antibodies directed ... | 1977 | 337735 |
| bristol laboratories division, bristol-myers company, syracuse, n.y. | | 1978 | 348086 |
| evaluation of an indirect immunoperoxidase test for identification of acholeplasma and mycoplasma. | | 1978 | 353224 |
| acid-soluble nucleotides of acholeplasma (mycoplasma) laidlawii a. | a study was made of the acid-soluble nucleotides present in acholeplasma (mycoplasma) laidlawii a during growth. the nucleotide pool of this organism is meagre, both qualitatively and quantitatively. the main nucleotides are uridine mono- and diphosphates, and none of the more complex nucleotide compounds, such as uridine diphosphate (udp) sugars or sugar peptides, required for cell wall formation, were detected. the nucleotide composition of a. laidlawii a is compared with that of the streptoco ... | 1978 | 358744 |
| mechanisms of thermophily. | | 1978 | 365460 |
| simplified preparation of mycoplasmas, an acholeplasma, and a spiroplasma for scanning electron microscopy. | a simple, effective procedure was developed for scanning electron microscopic examination of mycoplasmas and similar organisms. cultivation of several mycoplasmal species, an acholeplasma, and a spiroplasma in broth media in leighton tubes with cover slips resulted in attachment of the organisms to the cover slips. the attached cells were easily processed for either scanning electron microscopy or light microscopy. by eliminating the need for centrifugation, which was used in previously describe ... | 1979 | 370106 |
| comparative studies between microbiological culture and uptake of uridine/uracil to detect mycoplasmal infection of cell cultures. | | 1979 | 376320 |
| alteration of colonial morphology of acholeplasma laidlawii and acholeplasma modicum by infection with mycoplasmatales viruses. | morphologically aberrant colonies resulted from the infection of acholeplasma laidlawii with two of its three known viruses and from acholeplasma modicum cells naturally carrying virus. the patterns of colonial alteration differed between cells infected with the two a. laidlawii viruses. colonies derived from single cells infected with the bullet-shaped virus mv-l1 (mycoplasmatales virus-laidlawii-1) had a radial sectoring pattern of intracolonial swellings ("blebs"), whereas cells infected with ... | 1979 | 378947 |
| [comparative study of rosette and plaque formation in rats infected with mycoplasma arthritidis and acholeplasma laidlawii]. | m. arthritidis suppresses rosette- and plaque-formation in rats infected with this strain of mycoplasma. on the 15th day the immune response was restored in the control and experimental groups of animals. in later stages a strong stimulation of rfc and pfc was recorded, which levelled on day 150. on the contrary, a. laidlawii stimulated rfc and pfc in all stages of infection. a relationship between the phenomena described and pathogenic properties of the mycoplasma is discussed. | 1979 | 380687 |
| [action of mycoplasma arthritidis and acholeplasma laidlawii on the immunological reactivity of balb/c mice infected with the rauscher leukemia virus]. | | 1979 | 389300 |
| isolation of mycoplasmas from milk, lungs, and prepuce of cattle. | | 1979 | 398242 |
| growth of an enveloped mycoplasmavirus and establishment of a carrier state. | the growth of an enveloped dna-containing mycoplasmavirus (mvl2 obtained from r.n. gourlay) has studied, by using the indicator host acholeplasma laidlawii strain ja1. from virus one-step growth curves, artificial lysis experiments, and infected cell growth curves, it was found that virus infection is nonlytic. newly infected cells grow slower and are osmotically more stable than uninfected cells. however, 4 to 6 h after infection, the cells reach a carrier state in which cell growth rate and os ... | 1977 | 405508 |
| lipoquinones of some bacteria and mycoplasmas, with considerations on their functional significance. | in a comparative study the lipoquinones of some chemoorganotrophic, facultatively aerobic bacteria, and representative acholeplasma, mycoplasma, spiroplasma, and thermoplasma strains were investigated. the quinones were partly purified by preparative thin layer chromatography of lipid extracts, and characterized by their difference spectra (reduced minus oxidized) and rf values. respiring bacteria expectedly contained benzoquinones and/or naphthoquinones in micromolar concentrations whereas some ... | 1977 | 413478 |
| alteration by cereolysin of the structure of cholesterol-containing membranes. | when erythrocyte membranes were treated with cereolysin, negatively stained and examined by electron microscopy, ring and arc-shaped structures were observed in the membrane. the outside diameter of the rings varied from 33 to 50 nm with a border thickness of 6.7 to 8.3 nm. the arcs varied in length from 33 to 170 nm with a border thickness of also 6.7 to 8.3 min. when right-side-out erythrocyte ghosts which had been treated with cereolysin were examined by electron microscopy after freeze-fract ... | 1978 | 414780 |
| physical characterization of the superhelical dna genome of an enveloped mycoplasmavirus. | mycoplasmavirus mvl2 is a nonlytic enveloped virion containing dna. this dna has been shown to be a double-stranded circular superhelical molecule of 11.8 kilobase pairs (7.8 x 10(6) daltons). the superhelix density is greater than that of phi x174 rfi but less than that of pm2 phage dna. a physical map of the mvl2 genome has been obtained using restriction endonucleases. | 1979 | 430595 |
| characterization of mycoplasmavirus mvl2 dna. | the size and molecular configuration of mycoplasmavirus mvl2 dna are presented. the dna was shown to be a covalently closed circular duplex molecule with a molecular weight of 7.4 x 10(6). in sucrose gradients at neutral ph, the form i and form ii dna molecules have sedimentation values of approximately 29s and 23s, respectively. under alkaline conditions, the form i and form ii have s values of 70 and 20, respectively. | 1979 | 430596 |
| studies on classification of acholeplasmas isolated from horses, cattle and abattoir sewage. | | 1979 | 430937 |
| the properties of gel state lipid in membranes of acholeplasma laidlawii as observed by 2h nmr. | | 1979 | 437110 |
| is the vertical disposition of mycoplasma membrane proteins affected by membrane fluidity? | the influence of the physical state of the membrane lipid matrix on the vertical disposition of membrane proteins was studied with acholeplasma laidlawii. changes in membrane fluidity were brought about by altering the fatty acid composition of membrane lipids, by changing the growth temperature, by aging of cultures and by inducing changes in the membrane lipid-to-protein ratio through treatment with chloramphenicol. the lactoperoxidase-mediated iodination technique was used to label membrane p ... | 1979 | 444513 |
| role of lipid fatty acyl composition and membrane fluidity in the resistance of acholeplasma laidlawii to complement-mediated killing. | | 1979 | 448140 |
| [lipid regulation of carbohydrate transport system in mycoplasma]. | cultivation of acholeplasma laidlawii cells in media containing unsaturated fatty acids results in changes of the physiological state of the membrane lipid bilayer due to preferable incorporation of an unsaturated fatty acid into lipids. the lipids are capable to regulate the transport activity since the transport rates for glucose, 3-o-methyl-c-glucose, glucerol and erythritol change considerably when the cells are cultivated in media containing different unsaturated fatty acids. the transport ... | 1979 | 454709 |
| lipid and lipopolysaccharide composition of acholeplasma oculi. | the total lipid content of acholeplasma oculi comprises 13.3% of the dry weight of the organism and is about equally distributed between the neutral lipids plus glycolipids and the phospholipids. the phospholipids were identified as phosphatidyl glycerol and diphosphatidyl glycerol. the glycolipid fraction contained o-alpha-d-glucopyranosyl-(1 leads to 1)-2,3-diacyl glycerol and o-alpha-d-glucopyranosyl-(1 leads to 2)-o-alpha-d-glucopyranosyl-(1 leads to 1)-2,3-diacyl glycerol. the neutral lipid ... | 1979 | 457607 |
| the use of the anti-acholeplasma activities of streptomyces culture filtrates for the screening of new antibiotics. | a screening method for new antimicrobial agents from streptomyces culture filtrates was developed. three different types of test organisms were used for determining the antimicrobial activities of the culture filtrates: they were (a) an antibacterial activity test against staphylococcus aureus, (b) an antimycoplasmal activity test against acholeplasma laidlawii, and (c) a cytotoxicity test against hela-s3 cells. the active filtrates showing antimicrobial spectra (anticellogram) which did not mat ... | 1979 | 462473 |
| on the interaction between intrinsic proteins and phosphatidylglycerol in the membrane of acholeplasma laidlawii. | | 1979 | 464610 |
| isolation of acholeplasmas and mycoplasmas from aborted horse fetuses. | | 1979 | 473533 |
| replication of mycoplasmavirus mvl51: vi. acriflavine stimulates growth of this single-stranded dna virus. | | 1979 | 486185 |
| lipid distribution in acholeplasma laidlawii membrane. a study using the lactoperoxidase-mediated iodination. | the lactoperoxidase-mediated radioiodination has been applied to study the transbilayer distribution of phospho- and glycolipids in acholeplasma laidlawii membranes. after radioiodination, about 5% of the 125i-iodine was found in membrane lipids. a comparison of the labeling intensities of the various lipid species between iodinated intact cells and isolated membranes revealed that the glycolipids monoglucosyldiglyceride and diglucosyldiglyceride are located almost exclusively in the outer half ... | 1979 | 486468 |
| prevalence of mycoplasmal bovine mastitis in california. | seven species of mycoplasma plus one or more unknown species were found to cause bovine mastitis in california. both the frequency of cases and number of species of mycoplasma in samples received at the laboratory have increased from 1976 to 1978. by survey, nearly 4% of samples of bulk tank milk from dairy farms were found to contain mycoplasma of potential pathogenic significance. acholeplasma laidlawii was frequently isolated from samples both from cows and from farm bulk tanks during wet, ra ... | 1979 | 507492 |
| unusual positional distribution of fatty acids in phosphatidylglycerol of sterol-requiring mycoplasmas. | | 1979 | 510549 |
| composition and molecular organization of lipids and proteins in the envelope of mycoplasmavirus mvl2. | mvl2 virus was purified from culture supernatants of infected acholeplasma laidlawii cells by differential centrifugation, followed by velocity centrifugation in sucrose gradients. the purified virus contained 0.08 to 0.1 mumol of lipid phosphorous per ml of viral protein. thin-layer chromatography of viral lipids revealed the presence of phospho-, glyco-, and phosphoglycolipids identical with those found in the host cell membrane, but the relative amount of phosphatidylglycerol was much lower t ... | 1979 | 513201 |
| comparison of mycoplasmatales virus mv-lg-ps2-l172 with plasmavirus mv-l2 and the other mycoplasma viruses. | mycoplasma virus mv-lg-ps2-l172 was sensitive to heat (56 degrees c/30 minutes), nonidet-p40 and ether. in these respects it resembled plasmavirus mb-l2. however, it differed from mv-l2 (and the other mycoplasma viruses, mv-l1, mv-l3 and bn1 virus) in reciprocal plaque inhibition and serum neutralization tests (mv-l2 only). by plaque formation on host lawns resistant to the different mycoplasma viruses, including mv-lg-ps2-l172, this latter virus was shown to be distinct from the other viruses, ... | 1979 | 518304 |
| pathogenicity of some mycoplasma and acholeplasma species in the lungs of gnotobiotic calves. | cloned cultures of 16 strains, representing nine different species of mycoplasma and acholeplasma, were inoculated intratracheally into gnotobiotic calves. strains of m bovirhinis, m canadense, m verecundum, a axanthum and a modicum did not produce visible pneumonic lesions and were not reisolated from the lungs. strains of m alkalescens and m arginini colonised the lower respiratory tract but failed to produce visible pneumonia. m bovigenitalium (strain m991/70) and m dispar (strain gri226) bot ... | 1979 | 523812 |