Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| characterization of the plasma membrane of mycoplasma laidlawii. vii. phase transitions of membrane lipids. | 1970 | 5473498 | |
| native and reformed mycoplasma laidlawii membranes compared by freeze-etching. | 1970 | 5473500 | |
| the effect of alterations in fatty acid composition and cholesterol content on the permeability of mycoplasma laidlawii b cells and derived liposomes. | 1970 | 5473512 | |
| amended nomenclature for strains related to mycoplasma laidlawii. | 1970 | 5487182 | |
| transfer ribonucleic acid from mycoplasma laidlawii a. | 1971 | 5545013 | |
| presence of two dna populations in mycoplasma laidlawii. | 1971 | 5551322 | |
| [fractionation of the population of mycoplasma laidlawii in urografin density gradient]. | 1971 | 5567637 | |
| electron microscopy of solubilized acholeplasma laidlawii membrane proteins reaggregated with mycoplasma pneumoniae glycolipids. | 1971 | 5579139 | |
| characterization of the plasma membrane of mycoplasma laidlawii. 3. the formation and aggregation of small lipoprotein structures derived from sodium dodecyl sulfate-solubilized membrane components. | 1968 | 5650390 | |
| characterization of the plasma membrane of mycoplasma laidlawii. iv. structure and composition of membrane and aggregated components. | 1968 | 5650391 | |
| mycoplasma membrane lipids: variations in fatty acid composition. | the fatty acid composition of the membrane polar lipids of mycoplasma laidlawii b can be dramatically altered. these variations reslut in characteristic morphological chlanges, and in most cases the cells remain viable. this organism should provide a useful system for clarifying the role of fatty acyl chains in biological membranes. | 1969 | 5777213 |
| mycoplasma laidlawii in human burns. | mycoplasma laidlawii was recovered from burns from 13 of 52 patients. in most cases, cocci or bacilli were isolated simultaneously. | 1969 | 5784230 |
| characterization of the plasma membrane of mycoplasma laidlawii. v. effects of selective removal of protein and lipid. | 1969 | 5792241 | |
| characterization of the plasma membrane of mycoplasma laidlawii. vi. potassium transport. | 1969 | 5792242 | |
| biosynthesis of glucosyl diglycerides by mycoplasma laidlawii strain b. | monoglucosyl diglyceride is synthesized from 1,2-diglyceride and uridine-5'-diphosphoglucose (udp); diglucosyl diglyceride from monoglucosyl diglyceride, and uridine-5'-diphosphoglucose by membranes of mycoplasma laidlawii strain b. all of these enzymatic activities reside in the membrane. membranes solubilized by detergent action or succinylation and acetone powders of membranes were inactive. requirements for mg(2+), udp, and appropriate lipid acceptor were demonstrated for biosynthesis of bot ... | 1969 | 5808075 |
| new sero-types of mycoplasma laidlawii isolated from mastitic milk and urogenital tracts of cattle. i. isolation of m. laidlawii. | 1969 | 5817669 | |
| the role of lipids in membrane transport in mycoplasma laidlawii. | 1969 | 5823712 | |
| morphology of mycoplasma laidlawii type a. ii. effect of glucose on growth and cellular morphology. | anderson, d. l. (university of minnesota, minneapolis), m. e. pollock, and l. f. brower. morphology of mycoplasma laidlawii type a. ii. effect of glucose on growth and cellular morphology. j. bacteriol. 90:1768-1777. 1965.-cells of mycoplasma laidlawii a grown in soy peptone-yeast extract (sp-ye) broth reached higher maximal titers than cells grown in sp-ye supplemented with 0.2% glucose, and remained viable longer than glucose-grown cells. moreover, addition of glucose to sp-ye markedly affecte ... | 1965 | 5854595 |
| mycoplasma laidlawii var. inocuum comb. nov. | 1964 | 5874544 | |
| carotenoids and cholesterol in membranes of mycoplasma laidlawii. | 1965 | 5882653 | |
| influence of lipid components of mycoplasma laidlawii membranes on osmotic fragility of cells. | razin, s. (university of connecticut, storrs), m. e. tourtellotte, r. n. mcelhaney, and j. d. pollack. influence of lipid components of mycoplasma laidlawii membranes on osmotic fragility of cells. j. bacteriol. 91:609-616. 1966.-lipid composition of mycoplasma laidlawii membranes could be significantly changed by variations in the growth medium. the effect of these changes on the osmotic fragility of the cells was studied. cholesterol, incorporated into the membrane from the growth medium, had ... | 1966 | 5883100 |
| growth inhibition of mycoplasma by inhibitors of polyterpene biosynthesis and its reversal by cholesterol. | smith, paul f. (university of south dakota, vermillion), and carl v. henrikson. growth inhibition of mycoplasma by inhibitors of polyterpene biosynthesis and its reversal by cholesterol. j. bacteriol. 91:1854-1858. 1966.-compounds which inhibit enzymatic reactions in the biosynthetic pathway to carotenoids inhibited growth of a sterol-nonrequiring species, mycoplasma laidlawii, strain b, and m. hominis, strain 07. since m. hominis lacks the enzymes for polyterpene biosynthesis, the inhibitory co ... | 1966 | 5937241 |
| role of carotenoids and cholesterol in the growth of mycoplasma laidlawii. | 1967 | 6025421 | |
| a comparison of the osmotic and passive permeability properties of mycoplasma laidlawii and mycoplasma hominis. | 1967 | 6035538 | |
| characterization of the plasma membrane of mycoplasma laidlawii. i. sodium dodecyl sulfate solubilization. | 1967 | 6048810 | |
| glucolipids from mycoplasma laidlawii and streptococcus mg. | 1967 | 6049904 | |
| characterization of the plasma membrane of mycoplasma laidlawii. ii. modes of aggregation of solubilized membrane components. | 1967 | 6058126 | |
| [proteins of bacterial membranes. h+-adenosinetriphosphatase from acholeplasma laidlawii cells]. | the cytoplasmic membrane of micoplasmic cells, in particular of a. laidlawii cells, contains a proton-carrier mg2+ -activated atpase. a whole h+ -atpase complex (f0-f1) was isolated from these cells and characterized. the isolation procedure included solubilization of the enzyme with triton x-100 followed by ion-exchange chromatography on deae-cellulose and gel filtration on sepharose 6b. the enzyme was inhibited by dicyclohexylcarbodiimide (10(-4) m). the km value for atp hydrolysis and ki for ... | 1982 | 6123348 |
| effects of pressure and pressure antagonists on the growth and membrane-bound atp-ase of acholeplasma laidlawii b. | 1. arrhenius plots of the membrane-bound atp-ase were constructed at pressures of 300, 600 and 900 atm. pressure shifts the plots to higher temperatures with an increase in slope. 2. these data are partially consistent with a kinetic model in which a phase transition in the lipids associated with the atp-ase determines the activity of the enzyme. they are also consistent with a model in which the non-linear arrhenius plot is caused by the low temperature inactivation of the enzyme, upon which pr ... | 1982 | 6125309 |
| purification and characterization of the membrane (na+ + mg2+)-atpase from acholeplasma laidlawii b. | the membrane (na+ + mg2+)-atpase of acholeplasma laidlawii b has been solubilized with a brij-58/sodium deoxycholate mixture and purified by a combination of gel filtration and ion-exchange chromatography. the purified, partially delipidated atpase has a specific activity of 195 mumol pi/mg protein per h, which could be enhanced by 25% upon the addition of exogenous phospholipids. the kinetic properties of the purified enzyme are similar to those of the native membrane-bound enzyme, suggesting t ... | 1983 | 6138096 |
| purification and characterization of a dutpase from acholeplasma laidlawii b-pg9. | dutp was purified 120-fold from extracts of acholeplasma laidlawii b-pg9 by blue-sepharose, phenyl-sepharose, hydroxyapatite, and deae-sephacel chromatography techniques. the only substrate for the enzyme was dutp with an apparent km of 4.5 microm. the only reaction products were dump and ppi. the dutpase did not exhibit any specific divalent cation requirement, but it was inhibited by edta. the enzyme was not inhibited by pi or p-hydroxymercuribenzoate. the molecular weight of the enzyme was es ... | 1984 | 6145699 |
| properties of the membrane-bound mg2+-atpase isolated from acholeplasma laidlawii. | 1984 | 6148965 | |
| selective killing of mycoplasmas from contaminated mammalian cells in cell cultures. | 1980 | 6156417 | |
| methylation patterns of mycoplasma transfer and ribosomal ribonucleic acid. | the methylation patterns of transfer and ribosomal ribonucleic acid (rna) from two mycoplasmas, mycoplasma capricolum and acholeplasma laidlawii, have been examined. the transfer rna from the two mycoplasmas resembled that of other procaryotes in degree of methylation and general diversity of methylated nucleotides, and bore particular resemblance to bacillus subtilis transfer rna. the only unusual feature was the absence of m5u from m. capricolum transfer rna. the methylation patterns of the my ... | 1980 | 6160144 |
| eliminating mycoplasmas from contaminated cell cultures. | mycoplasmas are bothersome contaminants in cell cultures. cells derived from various sources are subject to contamination and although many procedures have been suggested to eliminate the contaminating mycoplasmas, there is no simple, rapid and effective method for eliminating them. we have devised a method for the selective killing of mycoplasmas based on the differences between the nucleic acid metabolism of mycoplasmas and that of tissue culture cells. whereas the nutritional requirements of ... | 1981 | 6169683 |
| origins of the mycoplasmas: sterol-nonrequiring mycoplasmas evolved from streptococci. | we report the establishment of a phylogenetic relationship between the sterol-nonrequiring mycoplasmas (acholeplasma species) and streptococci. three specific antisera prepared against purified streptococcus faecalis fructose diphosphate aldolase and glyceraldehyde-3-phosphate dehydrogenase and pediococcus cerevisiae glyceraldehyde-3-phosphate dehydrogenase were used for comparative enzyme immunological studies; the ouchterlony double-diffusion technique and the quantitative microcomplement fixa ... | 1982 | 6176574 |
| elucidation of the antigenic architecture of the acholeplasma laidlawii cell membrane by immunoabsorption in combination with crossed immunoelectrophoresis. | immunoabsorption in combination with crossed immunoelectrophoresis was used for elucidation of the antigenic architecture of the acholeplasma laidlawii cell membrane. when cells were grown in a medium containing cholesterol and unsaturated fatty acids, the cell membranes became fragile. membrane proteins or membrane fragments, which under some conditions seemed to be enriched in specific proteins (especially protein t2), were released into the growth medium. therefore, most of the experiments we ... | 1982 | 6181548 |
| polyacrylamide gel electrophoresis: recovery of non-stained and stained proteins from gel slices. | following electrophoresis or isoelectric focusing in gels of polyacrylamide the protein band of interest is cut out and placed above a sucrose gradient column, containing carrier ampholytes (pharmalyte). by electrophoresis, isoelectric focusing or displacement electrophoresis the proteins migrate out of the gel slice and into the isoelectric focusing column for concentration and further purification. from this column, the proteins can be withdrawn and their isoelectric points determined. even af ... | 1983 | 6187792 |
| yet another improved silver staining method for the detection of proteins in polyacrylamide gels. | silver staining is very sensitive for detection of proteins in polyacrylamide gels and different procedures have been published. by combining and modifying some of the recipes, a very reproducible method, which is based upon staining with diamine complexes of silver, has been developed. the background staining is negligible and reduced silver does not precipitate on the gel surface. the technique works very well for sodium dodecyl sulfate-polyacrylamide gel electrophoresis in both homogeneous an ... | 1984 | 6203956 |
| molecular properties of membrane lipids and activity of a membrane adenosine triphosphatase from acholeplasma laidlawii b. | the effects of membrane lipid fluidity and phase state on enzyme activity were evaluated by careful analysis of arrhenius plots of the na+, mg2+-dependent adenosine triphosphatase (referred to hereafter as atpase) from acholeplasma laidlawii b membranes and differential thermal analysis of the membrane lipid phase transitions. arrhenius plots of the atpase activity in membranes containing only liquid-crystalline lipids are gently curved and have the same form regardless of the membrane fatty liv ... | 1982 | 6214837 |
| the effect of antibiotics against bovine mycoplasmas and ureaplasmas. | a combination of lincomycin-spectinomycin-tylosin was tested against several strains of mycoplasmas and acholeplasmas as might be encountered in bovine semen and shown to be effective against them. this combination as well as minocin , rosaramicin, rosoxacin, tiamulin, gentamicin and declomycin were tested in vitro against 58 isolates of ureaplasma from the bovine urogenital tract. the lincomycin-spectinomycin-tylosin combination, minocin , rosaramicin, tiamulin and declomycin were quite active, ... | 1984 | 6232992 |
| protein-lipid interactions in biological and model membrane systems. deuterium nmr of acholeplasma laidlawii b, escherichia coli, and cytochrome oxidase systems containing specifically deuterated lipids. | 1981 | 6256386 | |
| chronic exposure to inhaled anesthetics increases cholesterol content in acholeplasma laidlawii. | acholeplasma laidlawii cells were grown in cholesterol-enriched medium and exposed continuously to either air (control), 4.0 vol.% halothane in air at 1 atm pressure (4% atm halothane), or 80% cyclopropane in oxygen for 24 h at 37 degrees c. cells grown in the presence of 4% atm halothane or 80% cyclopropane had approximately twice as much membrane cholesterol content/mg protein as the control cells. cells grown in an anesthetic environment also tended to have a higher membrane cholesterol/phosp ... | 1981 | 6274406 |
| cytosine methylation of the sequence gatc in a mycoplasma. | mycoplasma virus l2 is subject to host-specific restriction and modification in acholeplasma laidlawii strains ja1 and k2. we have examined the dnas from both host cells and viruses propagated on these strains with respect to susceptibility to cleavage by restriction endonucleases and for dna base modifications. we show that, in strain k2 and l2 virus grown on k2 cells, cytosine in the sequence gatc is methylated to 5-methylcytosine and, although strain k2 and l2 viruses grown on k2 contain n6-m ... | 1982 | 6286600 |
| ribosomal rna genes in mycoplasma. | using southern blotting analysis with labelled mycoplasmal ribosomal rna as probe, two fragments (1 kb and 5 kb) were detected in an ecor i digest of mycoplasma capricolum dna. this analysis revealed that the 5 kb fragment carries both 16s rrna sequences and the entire 23s rrna gene of this mycoplasma. the 1 kb fragment contains 16s rrna sequences only. the 5 kb ecor i fragment has been cloned and used to characterize the structure of rrna cistrons in various mycoplasma strains. these experiment ... | 1982 | 6289267 |
| receptor sites for mycoplasmal viruses on acholeplasma laidlawii. | all three groups of mycoplasmal viruses tested, mvl1, mvl2, and mvl3, were inactivated by both membranes and lipoglycan from acholeplasma laidlawii strain ja1. the interaction was specific for components of a. laidlawii since no inactivation occurred with either membrane or lipoglycan from acholeplasma oculi. adsorption of virus was proved by the demonstration of radiolabeled virus-lipoglycan or virus-membrane particles that were separable in density gradients from either component alone. recept ... | 1982 | 6289406 |
| cholesterol and phospholipid uptake by mycoplasmas. | mycoplasma offer several unique advantages for investigating the mechanism controlling transfer and uptake of exogenous cholesterol and phospholipids by biomembranes, as their plasma membrane interacts directly with exogenous lipid donors and their endogenous lipid synthesis is restricted. growing cells of five species of mycoplasma were found to take up significant quantities of phosphatidylcholine and sphingomyelin as well as free and esterified cholesterol. in contrast, growing cells of three ... | 1982 | 6289408 |
| molecular organization and selective solubilization of lipids and proteins in the envelope of mycoplasmal virus l2. | the composition and molecular organization of mycoplasmal virus l2 (mvl2) were studied and compared with those of the cell membrane of the host, acholeplasma laidlawii strain ja1. the virus contained 0.2-0.25 mumol of polar lipids per mg of viral protein. the lipid species of the mvl2 were the same as those of the host cells. nevertheless, the proportions between the various polar lipids were different, with a much lower content of phosphatidylglycerol in the viral lipids. despite these quantita ... | 1982 | 6289409 |
| integration and lysogeny by an enveloped mycoplasma virus. | the 11.8 kilobase pair (7.8 x 10(6) mol. wt.) genome of mycoplasma virus l2 in lysogenic acholeplasma laidlawii cells was examined. for this study, dnas were analysed by agarose gel electrophoresis and viral dna sequences identified by dna-dna hybridization. l2 dna was found to be integrated into the lysogenic host cell chromosome at a unique site in both viral and cellular dna. the viral dna site was roughly mapped and the approximate time of integration during the l2 non-cytocidal infectious c ... | 1983 | 6308135 |
| the structure and function of the acholeplasma laidlawii plasma membrane. | 1984 | 6318828 | |
| purine metabolism in acholeplasma laidlawii b: novel ppi-dependent nucleoside kinase activity. | acholeplasma laidlawii b-pg9 was examined for 16 cytoplasmic enzymes with activity for purine salvage and interconversion. phosphoribosyltransferase activities for adenine, guanine, xanthine, and hypoxanthine were shown. adenine, guanine, xanthine, and hypoxanthine were ribosylated to their nucleoside. adenosine, inosine, xanthosine, and guanosine were converted to their base. no atp-dependent phosphorylation of nucleosides to mononucleotides was found. however, ppi-dependent phosphorylation of ... | 1984 | 6330034 |
| immunoglobulin a protease activity of ureaplasma urealyticum. | all of 14 serotype standards and 34 of 35 wild-type strains of ureaplasma urealyticum isolated from humans demonstrated an immunoglobulin a (iga) protease activity. this activity degraded radiolabeled human iga including iga1 but not igg or azocasein. the iga fragments were detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, followed by radioautography, and they had molecular weights of about 110,000 and 50,000. the iga protease activity persisted in 25 mm edta but was sensiti ... | 1984 | 6365962 |
| effects of mycoplasma contamination on the intra-cellular free amino acid pool and exopeptidases of cultured human diploid fibroblasts. | 1984 | 6379361 | |
| [the pathogenic properties of acholeplasma in experiments in guinea pigs]. | 1983 | 6400777 | |
| extraction of membrane lipids during fixation, dehydration and embedding of acholeplasma laidlawii-cells for electron microscopy. | 1983 | 6405040 | |
| mycoplasmal infection of insect cell cultures. | twenty-five cell cultures of three insect orders from eight laboratories were tested for mycoplasmal infection. acholeplasma laidlawii was detected in one culture, an incidence of 4.0%. a. laidlawii, mycoplasma orale, m. arginini, but not m. hyorhinis, could establish infections of drosophila dm-1 cell cultures at 25 degrees c. in prospective studies, drosophila dm-1 cultures were intentionally infected with broth-propagated a. laidlawii and m. hyorhinis. m. hyorhinis did not grow and was elimin ... | 1983 | 6413389 |
| effect of mycoplasma infection on pyruvate dehydrogenase complex activity of normal and pyruvate dehydrogenase complex-deficient fibroblasts. | the fermentative mycoplasmas a. laidlawii js, m. hyorhinis dbs-50, m. hyorhinis gdl and m. pneumoniae fh have very high apparent activities of pyruvate dehydrogenase (pdh) (ec 1.2.4.1) and pyruvate dehydrogenase complex (pdhc). infection of normal and pdhc-deficient fibroblasts with these mycoplasma species resulted in a marked increase of the specific activity of these two enzymes, and under certain conditions could conceal the enzymatic defect. the non-fermentative mycoplasmas m. salivarium vv ... | 1984 | 6423397 |
| insect cell cultures in the study of attachment and pathogenicity of spiroplasmas and mycoplasmas. | the insect cell lines dm-1 (drosophila melanogaster), as-2 (aceratagallia sanguinolenta) and ac-20 (agallia constricta) were infected with spiroplasmas, mycoplasmas and acholeplasma laidlawii. in dm-1 cultures maintained at 25 degrees c in m1a medium, all strains multiplied except m. hyorhinis and the uncultivable sex-ratio organism. spiroplasma citri r8a2, s. floricola bnr-1 and obmg, s. apis pps-1 and the strains bc-3, corn stunt spiroplasma (css) and 277f produced cytopathogenic effects (cpe) ... | 1984 | 6424527 |
| extraction of lipids during freeze-substitution of acholeplasma laidlawii-cells for electron microscopy. | cells of the bacterium acholeplasma laidlawii were rapidly frozen against a copper block cooled by liquid helium. the frozen cells were transferred to liquid nitrogen and subsequently to acetone or methanol at 183 k. after 24 h the cells were infiltrated at 203 k with a non-polar methacrylate resin of the same type as lowicryl hm20. the resin was cured at the same temperature. acetone extracted approximately 5% of the lipid content of the cells, methanol 15-45% and the resin only negligible amou ... | 1984 | 6429337 |
| effects of manganese on the growth and morphology of ureaplasma urealyticum. | all of the 14 serotype standard strains of ureaplasma urealyticum were inhibited to varying degrees by manganese. a 1 mm concentration of this cation either stopped growth or reduced the rate of growth in liquid medium. the presence of manganese also altered colonial morphology and cellular ultrastructure. inhibition was dose dependent and strain specific. this differential response allowed the serotype strains to be divided into two broad biotypes. for the first biotype (serotypes 1, 3, 6, and ... | 1984 | 6432835 |
| interspecies and intraspecies dna homology among established species of acholeplasma: a review. | radiolabeled dna probes prepared in vitro by the nick translation method were used to determine the nucleotide sequence homology among the eight established and one unclassified species of acholeplasma. very little dna homology (2 to 21 percent) was found among these nine distinct species and the heteroduplexes showed at least 15 percent mismatching as determined by thermal elution endpoints. the data obtained by hybridization analyses paralleled the results obtained by the growth inhibition and ... | 1983 | 6433583 |
| binding of mvl-2 virus to a. laidlawii cells. | binding of mvl-2 virus, whose envelope lipids were radioactively labeled, to a. laidlawii ja1 cells was determined and characterized. the binding followed first-order kinetics and was temperature-dependent. all mvl-2 particles were capable of binding to a. laidlawii cells. at least 75 percent of radioactive mvl-2 bound represented specific binding which was markedly inhibited by edta. virus infectivity was not essential for binding as inactivation of the virus by ultraviolet irradiation did not ... | 1983 | 6433585 |
| membrane lipid physical state and modulation of the na+,mg2+-atpase activity in acholeplasma laidlawii b. | careful analysis of the arrhenius plot of the na+,mg2+-atpase (atp pyrophosphohydrolase, ec 3.6.1.8) activity in acholeplasma laidlawii b membranes of varying fatty acid composition has been combined with differential thermal analysis of the membrane lipid phase transitions to evaluate the effects of membrane lipid properties on the enzyme activity. our results indicate that the enzyme is active only in association with liquid-crystalline lipids, exhibiting a significant heat capacity of activat ... | 1980 | 6445554 |
| [proteins of bacterial membranes. purification of soluble atpase from acholeplasma laidlawii]. | a purified preparation of atpase (factor f1) from the acholeplasma laidlawii was obtained. the purification procedure included extraction of the enzyme complex from the isolated membranes by ultrasonication, chromatography on deae-cellulose and gel filtration on sepharose 6b. the specific activity of the atpase was increased 30-fold as compared to the original activity. the km value for atp hydrolysis was 7,4 . 10(-4) m. adp competitively inhibited the enzyme (ki = 2,0 . 10(-4) m). ouabain (2,5 ... | 1980 | 6452174 |
| altered surface structure of acholeplasma laidlawii induced by mycoplasmavirus l3 infection. | 1981 | 6456906 | |
| purification and properties of a manganese-containing superoxide dismutase from acholeplasma laidlawii. | from the prokaryotic microorganism acholeplasma laidlawii the major manganese-containing superoxide dismutase has been purified to homogeneity, as judged by polyacrylamide gel electrophoresis. the molecular mass of the enzyme was found to be 41 500 da. it consists of two subunits of identical size and has an isoelectric point of 6.4. the enzyme contains 0.51 +/- 0.05 atoms of manganese per subunit. its amino-acid composition and light absorption spectra are presented and compared with mn- and fe ... | 1984 | 6469219 |
| two cholesterol pools in acholeplasma laidlawii membranes. | cholesterol exchange kinetics between [14c]cholesterol-labeled acholeplasma laidlawii and mycoplasma gallisepticum cells and phosphatidylcholine-cholesterol vesicles followed a biphasic curve, with faster exchange rates for a. laidlawii. the same biphasic curve was obtained with isolated membranes. cholesterol exchange between lipid vesicles and a. laidlawii cells depleted of phospholipids by phospholipase a2, fitted a monophasic linear curve. the data support the hypothesis that the biphasic ch ... | 1984 | 6479337 |
| autoxidation of acholeplasma laidlawii membranes. | autoxidation of acholeplasma laidlawii membranes (with equimolar ratio of palmitic and linoleic acid) lacks an obvious induction period, and the overall rate of disappearance of substrate does not follow closely that of typical autocatalytic kinetics. throughout the course of autoxidation, the major oxygenated products isolated were hydroperoxides (as hydroxy esters) and compounds that gave rise to trihydroxy esters. the yield of trihydroxy esters was appreciable even at the early stage of the o ... | 1984 | 6503621 |
| effects of acyl chain composition on production of mycoplasmavirus mv-l2 by acholeplasma laidlawii. | membrane-enveloped viruses obtain their lipid envelopes from the host cells. studies with animal viruses and different cell lines have shown that the composition of the virus envelope affects infectivity. in this study, acholeplasma laidlawii strain ja1 and the membrane-enveloped virus mv-l2 were used. in this system, it is possible to vary the "stiffness" of the host cytoplasmic membrane within a very wide range by adding different fatty acids to the growth medium. viruses with different envelo ... | 1984 | 6511354 |
| calorimetric and spectroscopic studies of lipid hydrocarbon chain order in the acholeplasma laidlawii membrane. | the thermotropic phase behavior of acholeplasma laidlawii b membranes, whose lipids were biosynthetically highly enriched with one of a wide variety of different types of fatty acyl groups, was studied by differential scanning calorimetry. the membrane-lipid-hydrocarbon chain orientational order of these membranes, in both the gel and liquid-crystalline states, was also investigated by 19f-nuclear magnetic resonance spectroscopy, using biosynthetically incorporated monofluoropalmitic acid probes ... | 1984 | 6511356 |
| fatty acyl chain structure, orientational order, and the lipid phase transition in acholeplasma laidlawii b membranes. a review of recent 19f nuclear magnetic resonance studies. | the orientational order parameters of monofluoropalmitic acids biosynthetically incorporated into membranes of acholeplasma laidlawii b in the presence of a large excess of a variety of structurally diverse fatty acids have been determined via 19f nuclear magnetic resonance (19f nmr) spectroscopy. it is demonstrated that these monofluoropalmitic acids are relatively nonperturbing membrane probes based upon physical (differential scanning calorimetry), biochemical (membrane lipid analysis), and b ... | 1984 | 6525566 |
| bacterial membranes and lipid packing theory. | recent physical studies on the lipids of biological membranes have emphasized the potential instability of the lamellar phase of mixtures of lipids containing unsaturated species of phosphatidylethanolamine, plasmenylethanolamine, or monoglycosyldiacylglycerols, all of which are important constituents of the membranes of different groups of prokaryotes. the polar lipid compositions of bacteria are examined in terms of lipid packing theory. this survey reveals that gram-negative species with high ... | 1984 | 6530599 |
| radiation studies of acholeplasma laidlawii: the role of membrane composition. | acholeplasma laidlawii, a mycoplasma, is unable to synthesize unsaturated fatty acids but it will incorporate them into its plasma membrane if they are supplied exogeneously. thus the fatty acid composition of the cell membrane can be defined by growing the organism in media containing specific fatty acids. we obtained cells with predominantly one type of unsaturated fatty acid (either oleic, linoleic or linolenic acid) or cells with only saturated fatty acid in the cell membrane. the cells were ... | 1983 | 6605325 |
| the effects of ionizing radiation on the peroxide content of a pure polyunsaturated lipid dispersion and of lipids and membranes derived from acholeplasma laidlawii. | dispersions of a pure unsaturated phospholipid, dilinoleoylphosphatidyl choline, formed conjugated diene hydroperoxides when irradiated in air with 7 mev electrons (150 gy and 300 gy). peroxide formation was optimized when the dispersions were irradiated in air at 37 degrees c at a dose rate of 5 gy/min. no significant loss of linoleic acid from the irradiated phospholipid dispersions was observed after doses of 150 or 300 gy. small amounts of thiobarbituric acid-reactive material were formed in ... | 1984 | 6607230 |
| [mycoplasma mastitis of cattle. 10. test of mycoplasma bovis, mycoplasma bovigenitalium and acholeplasma laidlawii for udder pathogenicity]. | 1983 | 6615132 | |
| [mycoplasma mastitis of cattle. 11. histological udder findings after experimental infection with mycoplasma bovigenitalium and acholeplasma laidlawii]. | 1983 | 6615133 | |
| uracil phosphoribosyltransferase from acholeplasma laidlawii: partial purification and kinetic properties. | uracil phosphoribosyltransferase was purified 34-fold from sonicated extracts of acholeplasma laidlawii by ammonium sulfate precipitation, binding to deae-sephadex, sephadex g-200 chromatography, and hydroxylapatite chromatography. the molecular weight of the enzyme by gel filtration was approximately 80,000. the ph optimum for phosphoribosylation was around 7.5, and the optimum mgcl2 concentration was 5 mm. initial velocity studies were conducted over a wide range of both uracil and 5-phosphori ... | 1983 | 6619094 |
| uridine phosphorylase from acholeplasma laidlawii: purification and kinetic properties. | uridine phosphorylase was purified 1,370-fold from sonicated extracts of acholeplasma laidlawii by ammonium sulfate precipitation, deae-sephadex column chromatography, hydroxylapatite chromatography, and sephadex g-200 fractionation. the molecular weight of the enzyme as determined by gel filtration was approximately 65,000. [u-14c]ribose-1-phosphate (rib-1-p), prepared enzymatically from [u-14c]inosine, was utilized in initial velocity studies of uridine synthesis, which indicated a sequential ... | 1983 | 6619095 |
| intraspecies genetic relatedness among strains of acholeplasma laidlawii and of acholeplasma axanthum by nucleic acid hybridization. | this study compares the intraspecies genetic relatedness among strains of two established species of acholeplasma. radiolabelled dna probes were prepared from three strains of acholeplasma laidlawii and two strains of acholeplasma axanthum, by using the nick translation method. the labelled dna probes of these two strains were hybridized to an excess of unlabelled dna from 12 strains of acholeplasma laidlawii and from six strains of acholeplasma axanthum, respectively. nucleic acid hybridization ... | 1983 | 6631407 |
| fluorine-19 nuclear magnetic resonance studies of lipid fatty acyl chain order and dynamics in acholeplasma laidlawii b membranes. a physical, biochemical, and biological evaluation of monofluoropalmitic acids as membrane probes. | fluorine-19 nuclear magnetic resonance spectroscopy offers a number of unique advantages for studies of lipid fatty acyl chain order and dynamics in model and biological membranes. however, the germinal difluoromethylene fatty acids commonly employed as 19f membrane probes appear to appreciably perturb the organization of model membranes and biomembranes. we have thus synthesized a series of specifically labeled monofluoropalmitic acids and evaluated these as suitable membrane probes. differenti ... | 1983 | 6652058 |
| fluorine-19 nuclear magnetic resonance studies of lipid fatty acyl chain order and dynamics in acholeplasma laidlawii b membranes. effects of methyl-branch substitution and of trans unsaturation upon membrane acyl-chain orientational order. | the hydrocarbon-chain orientational order parameters of membranes of acholeplasma laidlawii b enriched with straight-chain saturated, methyl iso-branched, methyl anteiso-branched, or trans-unsaturated fatty acids have been determined via fluorine-19 nuclear magnetic resonance spectroscopy (19f nmr). a theoretical description of the 19f nmr spectral line shape is presented that permits the determination of the orientational order parameters associated with specifically monofluorinated palmitic ac ... | 1983 | 6652059 |
| synthesis of adenylate nucleotides by mollicutes (mycoplasmas). | cultures of the mollicutes (mycoplasma) acholeplasma laidlawii b, acholeplasma morum, mycoplasma bovis, mycoplasma arginini, mycoplasma fermentans and mycoplasma gallisepticum, representing four metabolic groups, were sampled at intervals over a 40 to 50 h period and assayed for the numbers of c.f.u., changes in ph and glucose concentration, and concentrations of atp, adp, amp, lactate and pyruvate. the adenylate energy charge (eca), the mean generation time, and the number of nmol of atp (mg dr ... | 1983 | 6655457 |
| transport activity of mouse spleen lymphocytes after their interaction in vitro with acholeplasma laidlawii cells. | transport of two non-metabolized carbohydrates (3-o-methyl-d-glucose, 3-o-mg, and 2-deoxy-d-glucose, 2-dg) into mouse spleen lymphocytes after their interaction with acholeplasma laidlawii cells has been studied. incubation of a. laidlawii cells and particularly the liposomes prepared from a. laidlawii membrane lipids enhances the rates of the both carbohydrates transport. this treatment resulted in increasing of the vmax values of 3-o-mg and 2-dg without changing the km values. this stimulation ... | 1983 | 6659737 |
| [interaction of acholeplasma laidlawii and mycoplasma arthritidis with the lymphocytes of mice of different strains]. | the interaction of mycoplasmas and mouse lymphocytes has been studied by the microbiological and electron-microscopic methods. the experiments have shown that a. laidlawii and m. arthritidis are adsorbed on lymphocytes and thymocytes of (c57bl6 x a/he)f1, balb and c57bl mice after 15 minutes of their joint incubation at 37 degrees c, 1 hour later adsorption reaches its maximum intensity and after further prolongation of the time of incubation the number of adsorbed microbial cells remains unchan ... | 1983 | 6659765 |
| [accumulation of cholesterol in acholeplasma laidlawii membranes in the steady-state phase of culture growth]. | in early logarithmic phase of growth of the a. laidlawii cells the lipid composition of plasma membrane is changed: the total lipid, glycolipid and phospholipid contents are decreased, while that of cholesterol changes only insignificantly. in late logarithmic and steady state phases the cholesterol level in the membrane is increased in parallel with the decrease of the phospholipid content. throughout the growth period a quantitative redistribution of membrane phospholipids in fatty acids and a ... | 1983 | 6661465 |
| [instability of host-virus association in acholeplasma laidlawii infected by a mycoplasma virus of the gourlay group l1]. | since l 1 mycoplasmaviruses have been described by gourlay for acholeplasma laidlawii, two hypotheses tried to explain the relationships between virus and host, the first by a "gradual lysis", the second on the basis of a "reduced growth" of infected acholeplasmas. neither has implied that susceptible cells, free of virus, can be obtained from infected populations, the cells being supposed to die according to the first and to be all infected but still slowly dividing according to the second hypo ... | 1983 | 6675342 |
| 19f-nuclear magnetic resonance study of glycerolipid fatty acyl chain order in acholeplasma laidlawii b membranes. | the technique of 19f-nuclear magnetic resonance (19f-nmr) spectroscopy offers a number of advantages for studies of lipid fatty acyl chain orientation and dynamics in biomembranes. however, the geminal difluoromethylene fatty acid probes usually employed in such studies appreciably perturb the organization of lipid bilayers. we have thus synthesized a series of specifically monofluorinated palmitic acids and carried out biophysical, biochemical, and physiological studies establishing their suita ... | 1983 | 6679141 |
| survey of plasmids in various mycoplasmas. | thirty-three strains representing 15 distinct mycoplasma, acholeplasma, and spiroplasma species were examined for the presence of plasmid dna by agarose gel electrophoresis. the electrophoretic patterns of the dnas of three strains, mycoplasma sp. strain 747, spiroplasma mirum strain smca, and m. hominis strain 1257, suggested the presence of a plasmid with molecular weights of approximately 70, 10, and 9 megadaltons, respectively. the functions of these plasmids are currently unknown. | 1983 | 6679154 |
| persistence of acholeplasma laidlawii in an established cell line rl 19. 1. host-parasite morphology. | the cell-parasite relationship of epitheloid cells from the established liver cell line rl 19 persistently infected with acholeplasma laidlawii was studied by transmission electron microscopy and scanning electron microscopy. the predominantly filamentous, branched a. laidlawii were arranged horizontally on the cell surface between microvilli at the cell margin. the cell adhesion, spreading, growth pattern and cell surface shape were not altered in relation to uninfected cultures of the same cel ... | 1983 | 6685661 |
| effect of novobiocin on mycoplasma virus l2 replication. | l2 is a temperate mycoplasma virus containing 11.8 kilobase pairs of negatively superhelical double-stranded dna. we observed l2 dna with less superhelicity in novobiocin-treated cells than that in untreated cells. however, although no change in viral dna superhelicity could be found in novobiocin-treated novobiocin-resistant cells, l2 production decreased in these novobiocin-treated cells. | 1984 | 6690717 |
| isolation and pathogenicity of mycoplasmas from geese. | several mycoplasma isolation trials were performed on infertile goose eggs and goose embryos which died during incubation, as well as on geese of different ages. a total of 43 out of 110 goose eggs proved to be contaminated by mycoplasmas. upon autopsy of birds which laid positive eggs, lesions were observed in the airsacs. mycoplasmas could be isolated from their air sacs and oviduct. four out of 15 strains examined biochemically and serologically with antisera prepared against all known avian ... | 1984 | 6712063 |
| [comparative study of transformation and fusion induced by polyethylene glycol in acholeplasma laidlawii b]. | this study showed in acholeplasma laidlawii the possibility of transformation and fusion of protoplasts after induction by polyethylene glycol. recombination in a genome of the resistance to chloramphenicol and neomycin has been obtained. minimal inhibitory concentration of these antibiotics towards the recombined strain are identical to those measured with the parental strains. the most suitable experimental conditions have been studied. it appeared that the fusion, which is cared out more easi ... | 1984 | 6713302 |
| elimination of mycoplasmas from cell cultures and establishment of mycoplasma-free cell lines. | several antibiotics were examined for their potential to eliminate mycoplasmas from contaminated cell cultures. acholeplasma laidlawii, mycoplasma arginini, mycoplasma hyorhinis and mycoplasma orale were effectively eliminated from experimentally contaminated mouse fibroblasts and mink epithelial cells by the use of the antibiotics minocycline and tiamutin . an elimination procedure was established, which involved the consecutive treatment of the cultures over a period of 3 weeks, followed by ce ... | 1984 | 6723803 |
| detection of mycoplasmas infecting cell cultures by dna hybridization. | infection of cell cultures by mycoplasmas can be detected and the mycoplasma identified by southern blot hybridization of the eco ri-digested dna of the suspected cell cultures with a nick-translated probe consisting of cloned ribosomal rna genes of mycoplasma capricolum. the probe does not hybridize with eukaryotic dna. the hybridization pattern with mycoplasmal dna is species specific, enabling the identification of the four most prevalent mycoplasma contaminants, mycoplasma orale, mycoplasma ... | 1984 | 6724620 |
| [effect of the geroprotector 2-ethyl-6-methyl-3-hydroxypyridine chlorhydrate on the cell proliferation of acholeplasma laidlawii]. | 1984 | 6734406 | |
| emmy klieneberger-nobel award lecture: the protein fingerprints of mycoplasmas. | the proteins of 91 strains of mycoplasma from 19 established species and three groups of uncertain taxonomic position were separated by two-dimensional polyacrylamide gel electrophoresis. considerable variations in protein patterns were found among strains from the same species or subspecies; the percentage of matching spots (% of congruence) ranged from 42%-100%, but many proteins were strongly conserved in all strains of a given species. maps of these conserved proteins could be used to identi ... | 1982 | 6750757 |
| [equine mycoplasma typing using the direct immunofluorescence technic]. | 1982 | 6764691 | |
| dialogue between membranes and their lipid-metabolizing enzymes. | 1980 | 6768613 | |
| [polysaccharide participation in bacterial wall permeability]. | 1980 | 6773273 | |
| a novel method for the determination of electrical potentials across cellular membranes. ii. membrane potentials of acholeplasmas, mycoplasmas, streptococci and erythrocytes. | the membrane potentials of acholeplasma laidlawii, mycoplasma mycoides subsp. capri, mycoplasma gallisepticum, streptococcus faecalis and human erythrocytes have been determined by applying a novel technique. the membrane potentials were calculated simply from potassium concentrations determined by atomic absorption spectroscopy, and gravimetry. the versatility of the new technique is demonstrated by comparing our results with data obtained by different techniques. | 1980 | 6773575 |