Composition of membranes and mycelia ofStreptomyces levoris at different stages of growth

The composition of cell membranes and mycelia ofStreptomyces levoris, producer of the polyene antibiotic levorin, was studied. The membrane protein/lipid ratio was shown to be constant during growth of the microorganism. The membrane protein was found to be heterogeneous and to have a low molecular weight. The lipid component of the membranes consisted mainly of polar lipids—phosphatidyl ethanolamine, diphosphatidyl glycerol, and phosphatidyl inositol mannoside being predominant. During growth, the phospholipid content of the polar lipid fraction decreased, apparently due to replacement of phospholipids by phosphorus-free analogs.     

Phospholipid Alterations During Growth of Escherichia coli

As cultures of Escherichia coli progressed from the exponential growth phase to the stationary growth phase, the phospholipid composition of the cell was altered. Unsaturated fatty acids were converted to cyclopropane fatty acids, and phosphatidyl glycerol appears to have been converted to cardiolipin. With dual isotope label experiments, the kinetics of synthesis of cyclopropane fatty acid for each of the phospholipids was examined in vivo. The amount of cyclopropane fatty acid per phospholipid molecule began to increase in phosphatidyl ethanolamine at a cell density below the density at which this increase was observed in phosphatidyl glycerol or cardiolipin. The rate of this increase in phosphatidyl glycerol or in cardiolipin was faster than the rate of increase in phosphatidyl ethanolamine. After a few hours of stationary-phase growth, all the phospholipids were equally rich in cyclopropane fatty acids. It is suggested that the phospholipid alterations observed are a mechanism to protect against phospholipid degradation during stationary phase growth. Cyclopropane fatty acid synthetase activity was assayed in cultures at various stages of growth. Cultures from all growth stages examined had the same specific activity in crude extracts.     

Phospholipids activate cathepsin D

Total lipids as well as phospholipids extracted from the mitochondrial-lysosomal fraction of porcine adrenal cortex activated the lysosomal cathepsin D of this tissue 30- and 40-fold, respectively, with bovine serum albumin as the substrate. Phosphatidic acid, phosphatidyl ethanolamine, phosphatidyl serine, phosphatidyl inositol, phosphatidyl glycerol and cardiolipin were found to activate greatly the cathepsin D. The degree of activation ranged from 6-fold by phosphatidyl ethanolamine to 40-fold by cardiolipin at 1 mM, respectively. These results strongly point to the importance of phospholipids in intracellular protein degradation by lysosomal cathepsin D.     

Alterations in the phospholipid composition of Escherichia coli B during growth at different temperatures

The major phospholipid classes of Escherichia coli B, phosphatidyl ethanolamine, cardiolipin, and phosphatidyl glycerol, were quantitated at different stages of the growth cycle. The organisms were incubated at both 27 and 37 C. Significant differences were observed both in the amounts of total lipid phosphorus per gram (dry weight) of cells and in the relative percentages of the individual phospholipids. At 37 C the total amount of lipid phosphorus decreased significantly throughout the growth cycle. However, at 27 C total lipid phosphorus accumulated. The patterns of the three major phospholipid classes of Escherichia coli exhibited complex quantitative changes. In addition, some evidence based on glycerol to phosphate molar ratios indicated that phosphatidyl glycerolphosphate replaced phosphatidyl glycerol during the late growth stages of E. coli B when grown at 27 C. A comparative analysis of phospholipid and fatty acid patterns led to a hypothesis attempting to explain some reported variations in the lipid composition of E. coli under different conditions of growth.     

Effects of prolactin and androgens on seminal vesicular lipids of castrated mature bonnet monkeys Macaca radiata

Effects of prolactin (PRL), bromocriptine (Br), testosterone propionate (TP), dihydrotestosterone (DHT) and the combination of these androgens with PRL/Br on the total lipid, total cholesterol, total glyceride glycerols, total phospholipid and their fractions in seminal vesicles of castrated mature monkeys were studied. Glyceride glycerols formed the major portion (50%) of total lipids in normal monkeys. Cholesterol and phospholipids were of equal share (25%). Esterified cholesterol formed major share (75%) of total cholesterol. Diacyl glycerol was the major (60%) glyceride glycerol and phosphatidyl choline and ethanolamine were the major phospholipid classes. Except triacyl glycerol castration markedly decreased all the lipid classes. PRL restored normal free and esterified cholesterol and phosphatidyl inositol but Br invariably decreased all the lipid classes. TP/DHT treatment stimulated the free and esterified cholesterol more than the control; it restored the normal glyceride glycerols. Phosphatidyl inositol, choline and ethanolamine were stimulated by androgens and other phospholipid classes were brought to normal. Addition of PRL + TP/DHT markedly increased esterified cholesterol, phosphatidyl inositol, choline, ethanolamine and phosphatidic acid. In all these aspects, Br counteracted the effects of androgens and PRL.     

Lipids of Cuscuta reflexa and changes in lipids of its host plants after infection

The lipid level (fresh weight basis) of Cuscuta reflexa Roxb. was related to the lipid content of the host plants Meilicago saliva L., Helianthus annuus L., Pisum sativum L. and Lantana camara L. Parasitizing by the dodder significantly increased the total lipid level of the hosts. The increase was mainly due to enhancement in the neutral lipid fraction.
The level of phospholipid in the parasite was always higher than in its hosts. Phospholidyl choline and phosphatidyl ethanolamine constituted about 65% of the total phospholipid of Cuscuta. This was followed by phosphatidyl inositol (ca 20%) and phosphatidyl glycerol (ca 12%). Phosphatidic acid constituted only ca 3% of the phospholipids of Cuscuta. Although the total phospholipid levels of various host plants were not affected as a result of the infection by Cuscuta, a significant decrease occurred in the levels of phosphatidyl eholine and phosphatidyl ethanolamine as well as marked increases in phosphatidyl inositol and phosphatidic acid. The infected tissue showed an increase in phospholipase D activity as compared with the controls. The results have been discussed in relation to changes in permeability of the infected tissue.     

Removal of the sphingolipid impurity from preparations of yeast phosphatidyl inositol

A complex sphingolipid containing inositol and mannose, present in lipid extracted from toluene-autolyzed baker's yeast, was eluted from silicic acid columns immediately after phosphatidyl inositol, and was the main nitrogenous impurity in crude preparations of this phospholipid. Nitrogenfree phosphatidyl inositol was obtained by rechromatography on alumina. Modifications to the chromatographic procedure also gave diphosphatidyl glycerol containing the theoretical 4.29% P.     

Inhibition of chilling-induced photooxidative damage to leaves of Cucumis sativus L. by treatment with amino alcohols

The effect of pretreatment of cucumber (Cucumis sativus L.) roots with choline chloride or ethanolamine on leaf phospholipid composition and light-induced leaf damage during chilling was studied. Photooxidative chlorophyll degradation was similarly inhibited by both amino alcohols. The decrease of the chlorophyll a/chlorophyll b ratio and the increase of polyunsaturated-fatty-acid degradation during chilling in the light were equally inhibited by pretreatment with choline chloride or ethanolamine. Treatment with choline chloride and ethanolamine caused, respectively, 43% and 26% increases in the total phospholipid contents of the leaves. After treatment with choline chloride, the phosphatidylcholine content was higher than the content of phosphatidylethanolamine; the reverse was true after treatment with ethanolamine. The chlorophyll concentration increased less than the phospholipid concentration, resulting in a decreased chlorophyll/phospholipid ratio of treated leaves. During chilling in the light, degradation of phosphatidylcholine, ethanolamine and phosphatidyl glycerol occurred. Phosphatidyl glycerol was less sensitive than phosphatidylcholine and ethanolamine. The degradation was equally inhibited by pretreatment with either amino alcohol. Possible connections between the phospholipid content of leaf membranes and the inhibition of chilling-induced photooxidative leaf damage are discussed.Abbreviations CC choline chloride - Chl chlorophyll - EA ethanolamine - PC phosphatidyl choline - PE phosphatidyl ethanolamine - PG phosphatidyl glycerol     

Cardiolipin-Specific Phospholipase D Activity in Haemophilus parainfluenzae

A highly active phospholipase D that is specific for cardiolipin was detected in the gram-negative bacterium Haemophilus parainfluenzae. Previously reported phospholipase D preparations have come exclusively from higher plants. The bacterial enzyme hydrolyzed cardiolipin to phosphatidyl glycerol and phosphatidic acid. During the incubation, phosphatidic acid disappeared. Phosphatidyl ethanolamine, methylated phosphatidyl ethanolamines, phosphatidyl choline, and phosphatidyl glycerol were not hydrolyzed when cardiolipin was rapidly hydrolyzed.     

Chemotaxonomy of aerobic Actinomycetes: Phospholipid composition

A survey of the phospholipid composition of 97 strains representing 20 genera of the Actinomycetales showed that five groups could be distinguished on the basis of the presence or absence of certain nitrogenous phospholipids. Phospholipid type PI (no nitrogenous phospholipids) is characteristic of the genera Actinomadura (madurae, pelletieri).Corynebacterium, Microtetraspora and Nocardioides. Actinomycetes of Type PII contain only one nitrogenous phospholipid, phosphatidyl ethanolamine. These include members of the genera Actinoplanes, Chainia, Dactylosporangium, Microellobosporia, Micromonospora, Micropolyspora (brevicatena), Mycobacterium, Nocardia (all species examined but autotrophica), Streptomyces and Streptoverticillium. Phospholipid pattern type PIII (characteristic phospholipid, phosphatidyl choline) was found in Actinomadura (dassonvillei). Micropolyspora (faeni), Nocardia (autotrophica), and Pseudonocardia. Actinomycetes having a type P IV pattern contain an unknown, previously undescribed phospholipid containing glucosamine (GluNU) which was found to be characteristic of members of the genera Intrasporangium, Microbispora and Streptosporangium. Actinomycetes of type PV contain phosphatidyl glycerol in addition to GluNU and include members of the genera Promicromonospora and Oerskovia. Other phospholipids found variably in all groups included phosphatidyl inositol, phosphatidyl inositol mannosides, phosphatidyl methylethanolamine, acyl phosphatidyl glycerol (APG) and diphosphatidyl glycerol (DPG). The fatty acids present in DPG (or APG when DPG was absent) may be species-specific. The chemical heterogeneity of the genera Actinomadura, Corynebacterium, Micropolyspora and Nocardia is discussed.     

Turnover of Phospholipids in Normal and Phosphorus-deficient Spirodela

When ³²P₁ was supplied as a 15-minute pulse to normal Spirodela oligorrhiza plants, the first phospholipid to become fully labeled was phosphatidic acid. Phosphatidyl glycerol reached maximum labeling before the other major phospholipids. In phosphorus-deficient plants, however, phosphatidyl glycerol became labeled much more slowly than either phosphatidyl choline or phosphatidyl ethanolamine, and also the proportion of phosphatidyl glycerol present was smaller. Thus, phosphatidyl glycerol synthesis is sensitive to phosphorus deficiency. Since most of the phosphatidyl glycerol present in Spirodela was localized in the chloroplast, this effect appeared to be specifically one on chloroplast composition. The phosphorus-deficient chloroplast had a 60% lower phospholipid content and a normal phospholipid pattern, but the phospholipid which was present was apparently cycling much less rapidly. Zeatin, which ameliorates the visual symptoms of phosphorus deficiency, also reduces the effect of phosphorus deficiency on phospholipid synthesis.     

Effect of phospholipids on estrogen receptor of rat uterine cytosol

Phospholipids such as phosphatidyl inositol and phosphatidyl serine inhibit the binding of R5020 and progestin receptors. The effect of phospholipids on the binding of estrogen and estrogen receptors of rat uterine cytosol was studied. Phosphatidyl choline, sphingomyelin, phosphatidyl inositol, phosphatidyl ethanolamine, cardiolipin, and phosphatidic acid inhibited the binding of estradiol and estrogen receptors. This inhibitory effect of phosphatidyl inositol and cardiolipin was dose dependent.     

Phosphoglycerides of Trichophyton terrestre and One Phenotype Selected from the Apollo 16 Microbial Ecology Evaluation Device

Total lipid extracted from wild-type Trichophyton terrestre CDC-X285 was found to be 2.0 percent of the dry cell weight. The total lipid contained the following phospholipid components identified by silicic acid-impregnated thin-layer and paper chromatography: phosphatidyl inositol, phosphatidyl choline, phosphatidyl serine, and phosphatidic acid. The total lipid extracted from the phenotype T. terrestre 7048-1 isolated from the Apollo 16 Microbial Ecology Evaluation Device (MEED) was found to vary according to the time at which the phospholipids were extracted. The Trichophyton phenotype was selected from a cuvette housed in the MEED exposed to specific space parameters including ultraviolet light of known wavelengths and energy levels in deep space. The phospholipid components, identified in the phenotype were phosphatidyl ethanolamine and cardiolipin. The major lipid fraction was composed of digalactosyl diglyceride and monogalactosyl diglyceride. An unusual lipid was detected in the phenotype, which appeared to be sterol glycoside.     

Phospholipid Composition and Metabolism of Micrococcus denitrificans

The phospholipid composition of Micrococcus denitrificans was unusual in that phosphatidyl choline (PC) was a major phospholipid (30.9%). Other phospholipids were phosphatidyl glycerol (PG, 52.4%), phosphatidyl ethanolamine (PE, 5.8%), an unknown phospholipid (5.3%), cardiolipin (CL, 3.2%), phosphatidyl dimethylethanolamine (PDME, 0.9%), phosphatidyl monomethylethanolamine (PMME, 0.6%), phosphatidyl serine (PS, 0.5%), and phosphatidic acid (0.4%). Kinetics of ³²P incorporation suggested that PC was formed by the successive methylations of PE. Pulse-chase experiments with pulses of ³²P or acetate-1-¹⁴C to exponentially growing cells showed loss of isotopes from PMME, PDME, PS, and CL with biphasic kinetics suggesting the same type of multiple pools of these lipids as proposed in other bacteria. The major phospholipids, PC, PG, and PE, were metabolically stable under these conditions. The fatty acids isolated from the complex lipids were also unusual in being a simple mixture of seven fatty acids with oleic acid representing 86% of the total. Few free fatty acids and no non-extractable fatty acids associated with the cell wall or membrane were found.     

Phospholipid changes in wheat and barley leaves under water stress

Total phospholipid content of leaves of wheat and barley increased and phospholipid components changed under water stress. Notable among these were the absence of phosphatidyl serine in barley varieties, decrease in phosphatidyl glycerol content in a less drought-tolerant variety of wheat (S-308) and barley (BG-25), and appearance of phosphatidic acid in both crops. The phospholipid content and its components did not return to normal upon release of the stress by subsequent irrigations. Such observations are indicative of water stress effected alterations in membranes.     

On the Ornithinyl Ester of Phosphatidylglycerol of Mycobacterium 607

Ornithinyl ester of phosphatidyl glycerol was found to accumulate in Mycobacterium 607 under acidic conditions (pH 5.6) of growth or in cultures of ultraviolet-irradiated (320 to 420 nm) bacilli. There was a corresponding decrease in cardiolipin content of the organisms under these conditions.     

Phospholipids of the Thiobacilli

Phosphatidyl glycerol, disphosphatidyl glycerol, and phosphatidyl ethanolamine were found in all of the Thiobacillus species studied. T. thioparus possessed only these phospholipids. T. intermedius, T. neapolitanus, and T. thiooxidans contained phosphatidyl-N-monomethylethanolamine, and T. novellus lipids contained phosphatidyl-N-monomethylethanolamine, phosphatidyl-N-N-dimethylethanolamine, and phosphatidyl choline, in addition to the three phospholipids common to all of the thiobacilli. Methionine was found to act as a methyl donor in the biosynthesis of the methylated forms of phosphatidyl ethanolamine. Phosphatidyl inositol was not detected in any of the organisms. Changing the nutrient medium did not result in a qualitative change in the phospholipid spectrum of the cultures.     

Inhibition of wall autolysis in Streptococcus faecalis by lipoteichoic acid and lipids.

Fully acylated lipoteichoic acid (LTA) isolated from Streptococcus faecalis ATCC9790 (S. faecium) inhibited autolysis of walls from the same organism at concentrations (1.0 to 1.5 nmol of LTA per mg of wall) comparable to those found in intact cells. Partially deacylated LTA isolated from S. faecalis or chemically deacylated LTA failed to inhibit significantly in the same concentration range. Beef heart cardiolipin and commercially obtained dipalmitoyl phosphatidyl glycerol were also found to inhibit wall autolysis in S. faecalis. Chemical deacylation of beef heart cardiolipin also removed the inhibitory activity of this molecule. Lipid fractions isolated from S. faecalis that inhibited wall autolysis were: diphosphatidyl glycerol (cardiolipin), phosphatidyl glycerol, aminoacyl phosphatidyl glycerol, and a neutral lipid fraction. Glycolipids were not found to be effective inhibitors. The possible role of LTA and/or certain lipids as regulators of cellular autolytic activity is discussed.     

Tightly associated cardiolipin in the bovine heart mitochondrial ATP synthase as analyzed by 31P nuclear magnetic resonance spectroscopy

The bovine heart F0F1-ATPase preparation (Serrano, R., Kanner, B., and Racker, E. (1976) J. Biol. Chem. 251, 2453-2461) has been further delipidated. The lipid-deficient preparation contained 2.5 mol of cardiolipin, 1 mol of phosphatidylcholine (PC), and 1 mol of phosphatidylethanolamine (PE) per mol of F0F1. When reconstituted with asolectin the delipidated preparation exhibited an activity of 13 mumol of ATP hydrolyzed/min/mg of protein which was 88% oligomycin-sensitive. The phospholipids in this preparation were analyzed by 31P NMR spectroscopy to determine if they were immobilized by the enzyme (rendered NMR-invisible). The PC and PE were below the limits of detection under the conditions utilized and the cardiolipin was NMR-invisible until the enzyme was denatured by addition of either 1% sodium dodecyl sulfate or 8 M urea. Addition of cardiolipin to the delipidated preparation and subsequent analysis by NMR spectroscopy revealed that approximately 4 mol of cardiolipin were immobilized per mol of F0F1 ATPase. The enzyme appears to have high affinity for cardiolipin exclusively, since PC (a prominent inner membrane lipid), phosphatidyl serine (an acidic phospholipid), and phosphatidyl glycerol (the precursor to cardiolipin) were not immobilized (rendered NMR-invisible) when added to the delipidated preparation.     

Effect of corticosterone on epididymal lipids in pubertal rat

Serum corticosterone excess was induced by the administration of corticosterone acetate to adrenal intact rats. Different lipid classes were studied in unwashed and washed (epididymal sperm and fluid free) caput and cauda epididymides. The unwashed caput epididymidis registered a significant decrease in total lipid, cholesterol and phospholipid while total glyceride glycerol and its fractions were not altered after corticosterone treatment. Among phospholipid fractions phosphatidyl inositol, choline and ethanolamine showed a significant decrease. Unlike the unwashed caput epididymidis, the washed caput region recorded a marked increase in total lipid, glyceride glycerol and its fractions. However, total lipid in the washed cauda region significantly increased and the increase was mainly due to triacyl glycerol. Though the phospholipid fractions phosphatidyl choline and ethanolamine showed an increase, the total phospholipid was not altered significantly. Serum testosterone and prolactin registered a significant decrease while gonadotropins were unaltered. On the withdrawal of corticosterone treatment, all the lipid classes turned to normalcy along with serum testosterone and prolactin. It is concluded that corticosterone excess favours lipid accumulation in the sperm free epididymal tissue and its influence on epididymis is region specific and reversible.