Modification of the Membrane Composition of Mycoplasma mycoides subsp. capri by the Growth Medium

Archer, David B.

doi:10.1099/00221287-88-2-329

Cited by 27 publications

(12 citation statements)

References 30 publications

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“…Mycoplasma species [order Mycoplasmatales; family Mycoplasmataceae (1)] require an external sterol source for growth (2,3), a nutritional dependence not found elsewhere among prokaryotes. Plant and animal sterols meet this requirement, and so do certain sterol derivatives, provided they contain the cholestane ring system (A/B trans), an unsubstituted equatorial hydroxyl group, and a branched aliphatic side chain eight or more carbon atoms in length (4,5). Similar structural features appear to be necessary for regulatory functions (e.g., solute permeability and viscosity) of sterols in biological or artificial membranes (6).…”

mentioning

confidence: 99%

Sterol requirement of Mycoplasma capricolum.

Odriozola¹,

Waitzkin²,

Smith³

et al. 1978

Proc. Natl. Acad. Sci. U.S.A.

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Mycoplasmas require an external source of sterol for growth. For Mycoplasma capicolum this requirement is met not only by cholesterol but also by the methylcholestane derivatives lanosterol, cycloartenol, 4, imethylcholesterol, and 43-methylcholestanol. Cholesteryl methyl ether and 3a-methylcholestanol serve equally well as sterol supplements. None of the growth-supporting sterol derivatives tested was metabolically modified. The unusual acceptance of diverse cholestane derivatives by a mycoplasma species contrasts with the structural attributes thought to be necessary for sterol function in eukaryotic membranes. Mycoplasma species [order Mycoplasmatales; family Mycoplasmataceae (1)] require an external sterol source for growth (2, 3), a nutritional dependence not found elsewhere among prokaryotes. Plant and animal sterols meet this requirement, and so do certain sterol derivatives, provided they contain the cholestane ring system (A/B trans), an unsubstituted equatorial hydroxyl group, and a branched aliphatic side chain eight or more carbon atoms in length (4, 5). Similar structural features appear to be necessary for regulatory functions (e.g., solute permeability and viscosity) of sterols in biological or artificial membranes (6). We describe here the growth response of Mycoplasma capricolum to a variety of previously untested sterols and biogenetically related substances. Our results show that the "sterol" specificity for M. capricolum growth is surprisingly broad. EXPERIMENTAL M. capricolum (California Kid strain 14, ATCC 27342) was kindly supplied by M. W. Grabowsky. Cells were grown on modified Edward medium (1). The PPLO-serum fraction was omitted and replaced by fatty acid-poor bovine serum albumin (Sigma, 5 mg/ml). Other additions were palmitic acid (5 ,g/ml) and elaidic acid (6.5 ,ug/ml). Sterols and other test compounds were dissolved in ethanol and added to the growth medium in the quantities indicated in the figure legends. Cells were grown in air in a 370 water bath without shaking. Growth was determined by measuring the optical density of the cultures at 640 nm. Initially the pH values of the culture media were 8.0, they declined with time as a function of cell density. Typically, in a culture grown on 10 gg of cholesterol per ml the optical density rose from 0.04 to 0.42 and the pH fell concurrently to 6.2. In some experiments (not shown) the Difco heart infusion broth, Difco Bacto-peptone, and the Difco yeast extract components of the modified Edward medium were delipidated by extraction with chloroform/methanol, 2:1 by volume. Delipidation did not significantly affect the growth response of mycoplasma to the various test compounds. For isolation of unsaponifiable fractions, cells were harvested at mid to late logarithmic phase by centrifugation at 12,000 X g for 15 min at 40. Resuspended pellets were washed once with 0.25 M NaCl, recentrifuged, and extracted with chloroform/methanol (2:1). Lipid extracts were saponified with 3 M KOH (1 hr at 70), and the nonsaponifiable materials were...

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mentioning

confidence: 99%

Sterol requirement of Mycoplasma capricolum.

Odriozola¹,

Waitzkin²,

Smith³

et al. 1978

Proc. Natl. Acad. Sci. U.S.A.

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“…4A, lane f). Cholesterol is an obligate nutrient for M. pulmonis and many Mollicute species (Argaman and Razin, 1965;Archer, 1975) a specific hydrophobic uptake mechanism may be present. The increase in specific binding observed following deacylation of SGG (Fig.…”

Section: Discussionmentioning

confidence: 99%

Male germ cell specific sulfogalactoglycerolipid is recognized and degraded by mycoplasmas associated with male infertility

Lingwood

Schramayr

Quinn

1990

Journal Cellular Physiology

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Sulfogalactosylglycerolipid (SGG) is the major mammalian male germ cell glycolipid and has been implicated in sperm/egg binding. Mycoplasma pulmonis, a species of Mollicutes, is associated with male infertility in rodents. Purified SGG incubated in the presence of M. pulmonis was enzymatically degraded by both desulfation and deacylation. Desulfation occurred primarily at alkaline pH, and deacylation also increased with increased pH, indicating that these represent novel enzymatic activities. Digestion was facilitated, but not dependent on, the presence of detergent. Rat spermatozoa exposed to M. pulmonis showed a reduction in SGG content which was particularly marked for cauda (mature) spermatozoa. With the aid of tlc overlay binding procedure, intact M. pulmonis were found to bind specifically to sulfated glycolipids and thus SGG may provide the cell membrane receptor for this organism. The topology of mycoplasma binding to rat sperm was consistent with the known topology of sperm SGG. The reduced binding (and subsequent digestion) of caput spermatozoan SGG correlates with the membrane colocalization of SGG and its endogenous binding protein at this stage. Separation of SGG and its binding protein during epididymal sperm maturation appears to facilitate M. pulmonis binding to and digestion of cauda sperm SGG. The binding and degradation of the sperm SGG by M. pulmonis may play a role in the induction of infertility which follows infection with these organisms by interfering in sperm/egg receptor recognition.

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“…In our studies, only membranes isolated by digitonin showed a lower specificity of attachment to sialic acid residues. This may be because the isolated membranes contain significant quantities of digitonin (2,28), differing from native membranes. The finding that isolated M. gallisepticum membranes may retain specific attachment capacity to RBC opens the way for isolation of binding sites from the membranes.…”

Section: Discussionmentioning

confidence: 99%

Attachment of killed Mycoplasma gallisepticum cells and membranes to erythrocytes

Banai¹,

Kahane²,

Feldner³

et al. 1981

Infect Immun

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To correlate viability with attachment capacity, Mycoplasma gallisepticum cells harvested at different growth phases and treated by various agents were tested for their capacity to attach to human erythrocytes. The results show that viability per se is not essential for M. gallisepticum attachment to erythrocytes, as cells killed by ultraviolet irradiation and membranes isolated by lysing M. gallisepticum cells by various means retained attachment capacity. However, treatment of the mycoplasmas by protein-denaturing agents, such as heat, glutaraldehyde, or prolonged exposure to low pH, drastically affected or even abolished attachment, supporting the protein nature of the mycoplasma membrane components responsible for specific binding to the sialoglycoprotein receptors on the erythrocytes.

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Modification of the Membrane Composition of Mycoplasma mycoides subsp. capri by the Growth Medium

Cited by 27 publications

References 30 publications

Sterol requirement of Mycoplasma capricolum.

Sterol requirement of Mycoplasma capricolum.

Male germ cell specific sulfogalactoglycerolipid is recognized and degraded by mycoplasmas associated with male infertility

Attachment of killed Mycoplasma gallisepticum cells and membranes to erythrocytes

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