scholarly journals Composition of the protoplast membrane from Saccharomyces cerevisiae

1968 ◽  
Vol 108 (3) ◽  
pp. 401-412 ◽  
Author(s):  
R. P. Longley ◽  
A. H. Rose ◽  
B. A. Knights
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Magnesium Chloride ◽  
Membrane Lipids ◽  
Dry Weight ◽  
Exponential Phase ◽  
Gas Liquid Chromatography ◽  
Liquid Chromatography Mass Spectrometry ◽  
Sterol Esters ◽  
Whole Cells ◽  
Fatty Acid Compositions

1. Protoplasts of Saccharomyces cerevisiae N.C.Y.C. 366 were prepared by incubating washed exponential-phase cells in buffered mannitol (0·8m) containing 10mm-magnesium chloride and snail gut juice (about 8mg. of protein/ml. of reaction mixture). Protoplast membranes were obtained by bursting protoplasts in ice-cold phosphate buffer (pH7·0) containing 10mm-magnesium chloride. 2. Protoplast membranes accounted for 13–20% of the dry weight of the yeast cell. They contained on a weight basis about 39% of lipid, 49% of protein, 6% of sterol (assayed spectrophotometrically) and traces of RNA and carbohydrate (glucan+mannan). 3. The principal fatty acids in membrane lipids were C16:0, C16:1 and C18:1 acids. Whole cells contained a slightly greater proportion of C16:0 and a somewhat smaller proportion of C18:1 acids. Membrane and whole-cell lipids included monoglycerides, diglycerides, triglycerides, sterols, sterol esters, phosphatidylcholine, lysophosphatidylcholine, phosphatidylethanolamine and phosphatidylinositol+phosphatidylserine. Phosphorus analyses on phospholipid fractions from membranes and whole cells showed that membranes contained proportionately more phosphatidylethanolamine and phosphatidylinositol+phosphatidylserine than whole cells, which in turn were richer in phosphatidylcholine. Phospholipid fractions from membranes and whole cells had similar fatty acid compositions. 4. Membranes and whole cells contained two major and three minor sterol components. Gas–liquid chromatography, mass spectrometry and u.v. and i.r. spectra indicated that the major components were probably Δ5,7,22,24(28)-ergostatetraen-3β-ol and zymosterol. The minor sterol components in whole cells were probably episterol (or fecosterol), ergosterol and a C29 di-unsaturated sterol. 5. Defatted whole cells contained slightly more glutamate and ornithine and slightly less leucine and isoleucine than membranes. Otherwise, no major differences were detected in the amino acid compositions of defatted whole cells and membranes.

The anther cuticle of Zea mays

1986 ◽  
Vol 64 (9) ◽  
pp. 2088-2097 ◽  
Author(s):  
P. C. Cheng ◽  
R. I. Greyson ◽  
D. B. Walden
Keyword(s):  
Zea Mays ◽  
Dry Weight ◽  
Gas Liquid Chromatography ◽  
Liquid Chromatography Mass Spectrometry ◽  
Hexane Extraction ◽  
Cuticular Membrane ◽  
Transmission Electron ◽  
Anther Cuticle ◽  
Cuticular Layer

The cuticular membrane of the anther of Zea mays is ridged or rugose over most of its surface. The ridges arise during anther development and are confined to the cuticular membrane itself with no coincident folding of the cell wall, although some fibrous wall-like material becomes incorporated within the ridges. The height of a ridge, on mature anthers, is about 0.5 μm and although ridges are aligned, for the most part, in the long axis of the organ, ridges are continuous across cell boundaries in all directions. From transmission electron microscope views we conclude that the cuticle is homogeneous with a thickness of approximately 100 nm. The cuticular layer can be removed from the underlying wall by ZnCl2–HCl hydrolysis. Older anthers yield intact cuticles with persistent ridges. The ridges are not retained by cuticles from young anthers. Chloroform or hexane extraction removes about 30% of the dry weight from isolated cuticles. Characterization of the extract by gas–liquid chromatography – mass spectrometry reveals it is mainly composed of a mixture of odd- and even-numbered straight-chain, saturated hydrocarbons (C25 to C34).

INFLUENCE OF AGE AND STAGE OF DEVELOPMENT ON THE NEUTRAL CARBOHYDRATE COMPONENTS IN ROOT EXUDATES FROM ALFALFA PLANTS GROWN IN A GNOTOBIOTIC ENVIRONMENT

1972 ◽  
Vol 52 (4) ◽  
pp. 633-642 ◽  
Author(s):  
R. A. HAMLEN ◽  
F. L. LUKEZIC ◽  
J. R. BLOOM
Keyword(s):  
Root Exudates ◽  
General Trend ◽  
Plant Root ◽  
Dry Weight ◽  
Plant Age ◽  
Gas Liquid Chromatography ◽  
Liquid Chromatography Mass Spectrometry ◽  
Qualitative And Quantitative ◽  
Stage Of Development ◽  
Carbohydrate Components

Investigations were carried out by gas–liquid chromatography–mass spectrometry on the neutral carbohydrate fraction of root exudates from DuPuits alfalfa plants grown gnotobiotically for 16 weeks. Carbohydrates detected were arabinose, ribose, xylose, fructose, mannose, glucose, inositol, sucrose, and maltose. Three components were not identified. A general trend was observed of decreasing concentration of total neutral carbohydrates released with increasing plant age; however, two components increased with time. Based on milligrams of carbohydrate released per gram of dry weight of root tissue, all carbohydrates decreased with increased plant age. Flowering plants produced a significant increase in amounts of material released over samples from clipped plants. The results support the view that age and stage of development are significant influences on the qualitative and quantitative nature of plant root exudates.

scholarly journals Production of Extracellular Polysaccharides by CAP Mutants of Cryptococcus neoformans

2009 ◽  
Vol 8 (8) ◽  
pp. 1165-1173 ◽  
Author(s):  
Jan Grijpstra ◽  
Gerrit J. Gerwig ◽  
Han Wösten ◽  
Johannis P. Kamerling ◽  
Hans de Cock
Keyword(s):  
Cryptococcus Neoformans ◽  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Extracellular Polysaccharides ◽  
Gas Liquid Chromatography ◽  
Liquid Chromatography Mass Spectrometry ◽  
Wild Type ◽  
One Dimensional ◽  
Whole Cells ◽  
First Time

ABSTRACT The human pathogen Cryptococcus neoformans causes meningoencephalitis. The polysaccharide capsule is one of the main virulence factors and consists of two distinct polysaccharides, glucuronoxylomannan (GXM) and galactoxylomannan (GalXM). How capsular polysaccharides are synthesized, transported, and assembled is largely unknown. Previously, it was shown that mutations in the CAP10, CAP59, CAP60, and CAP64 genes result in an acapsular phenotype. Here, it is shown that these acapsular mutants do secrete GalXM and GXM-like polymers. GXM and GalXM antibodies specifically reacted with whole cells and the growth medium of the wild type and CAP mutants, indicating that the capsule polysaccharides adhere to the cell wall and are shed into the environment. These polysaccharides were purified from the medium, either with or without anion-exchange chromatography. Monosaccharide analysis of polysaccharide fractions by gas-liquid chromatography/mass spectrometry showed that wild-type cells secrete both GalXM and GXM. The CAP mutants, on the other hand, were shown to secrete GalXM and GXM-like polymers. Notably, the GalXM polymers were shown to contain glucuronic acid. One-dimensional 1H nuclear magnetic resonance confirmed that the CAP mutants secrete GalXM and also showed the presence of O-acetylated polymers. This is the first time it is shown that CAP mutants secrete GXM-like polymers in addition to GalXM. The small amount of this GXM-like polymer, 1 to 5% of the total amount of secreted polysaccharides, may explain the acapsular phenotype.

Concentrations of non-glucose polyols in serum and cerebrospinal fluid from apparently healthy adults and children.

1984 ◽  
Vol 30 (2) ◽  
pp. 188-191 ◽  
Author(s):  
S Yoshioka ◽  
S Saitoh ◽  
S Seki ◽  
K Seki
Keyword(s):  
Mass Spectrometry ◽  
Cerebrospinal Fluid ◽  
Liquid Chromatography ◽  
Healthy Subjects ◽  
Metabolic Diseases ◽  
Gas Liquid Chromatography ◽  
Liquid Chromatography Mass Spectrometry ◽  
Adults And Children ◽  
Healthy Persons ◽  
Apparently Healthy

Abstract Six non-glucose polyols--mannose, fructose, 1-deoxyglucose, mannitol, glucitol, and inositol--were identified and evaluated in human serum and cerebrospinal fluid by gas-liquid chromatography and by gas-liquid chromatography/mass spectrometry. Concentrations of fructose, mannose, and inositol in the serum of healthy persons or children without metabolic diseases varied with age, as already reported for 1-deoxyglucose. Fructose, inositol, and glucitol concentrations in cerebrospinal fluid significantly exceeded those in serum. The method described here for determining polyols and for evaluating polyol patterns in serum, as well as the resulting data on children and healthy subjects, should be useful in investigations of the clinical and physiological significance of polyols.

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