Ratio Of Lipid Phosphorus Research Articles

Vitellogenin exists as charge isomers in the Indian freshwater murrel, Channa punctatus (Bloch)

Three charge isomeric forms of vitellogenin are reported in the blood of estrogen-treated murrel, Channa punctatus on the basis of the results of native and SDS–PAGE, isoelectric focusing, and Ferguson plot analysis. Vitellogenin was induced in adult murrels by exogenous administration of estradiol-17β and labelled with 32P in vivo. Labelled vitellogenin isolated from other plasma proteins on Ultrogel AcA 34 columns resolve into three bands on native-PAGE. Ferguson plot analysis reveals free electrophoretic mobilities of the three bands as 6.0, 4.5, and 3.7, which are very similar to the isoelectric point values of 5.9, 4.6, and 3.8, respectively. The apparent molecular weight of native murrel vitellogenin is 530 kDa. It consists of a single peptide with a molecular weight of 175 kDa. All the three bands on native PAGE resolves into a single peptide on SDS–PAGE. N-terminal amino acid sequence for murrel vitellogenin peptide is MKAVVLALLL. The protein phosphorus:lipid phosphorus ratio for murrel vitellogenin is 0.9. The total lipid content is 32.8%, consisting of 45% neutral lipids and 30% phospholipids. Phosphatidyl choline is the major phospholipid whereas triglycerides are the major neutral lipids. Results of these analytical analyses indicate that murrel native vitellogenin circulates as three charge isomers; poor in phosphorus but rich in lipids content.

Glycosphingolipids of cultured human colon carcinoma cells and their drug-resistant sublines

Human colon carcinoma cells were analyzed for lipid phosphorus, cholesterol and glycosphingolipids. Ceramide mono-, di- and trihexosides and sulfatides were isolated by column and thin-layer chromatography and determined quantitatively on the basis of their hexose content. The complex lipid fractions so isolated were only partially resolved with the material available. Gangliosides G M2 and 6 M2 and globoside were major components of the fraction and were determined on the basis of their hexose, hexosamine and neuraminic acid content. The HCT 116, 116a and 116b cells contained no fucolipids. Cell lines resistant to mitomycin C, teniposide and etoposide were developed and analyzed. Over the 5 year period of the study sulfatides declined to about one-fourth of their original amounts in both parent and drug-adapted cells. HCT 116 cells adapted to mitomycin C and teniposide had 30% less ceramide monohexoside and a 45% greater cholesterol to lipid phosphorus ratio than the parent cells. Reductions in ceramide dihexoside in the drug-adapted cells were greater than those of the ceramide monohexoside. Galabiosyl ceramide was the major ceramide dihexoside in all the cells and accumulated in HCT 116a to levels 4-6-fold greater than that of the other lines as the only dihexoside.

Co-localization of superoxide generation and NADP formation in plasma membrane fractions from human neutrophils.

In order to resolve discrepancies in the literature concerning the subcellular localization of NADPH oxidase, we disrupted human neutrophils by nitrogen cavitation and fractionated the subcellular organelles on a discontinuous sucrose density gradient. The lightest fraction was 20- to 40-fold enriched for plasma membranes as determined by the marker enzymes alkaline phosphatase and phosphodiesterase I as well as by the ratio of lipid phosphorus to protein. There was a significant decrease in the specific activities of the granule markers myeloperoxidase, lysozyme, and beta-glucuronidase. An intermediate fraction was enriched in membrane markers but not to the extent the lightest fraction was enriched. This fraction contained more granular contamination, as shown by the marker enzymes. In contrast, the densest bands of the gradient were enriched for granule markers with little contamination by plasma membrane. Superoxide generation and NADP formation were primarily associated with the two membrane-enriched fractions from polymorphonuclear leukocytes stimulated with phorbol myristate acetate. The NADP formation associated with a dense granule fraction observed previously in our laboratory was probably due to a cyanide-stimulated oxidation of NADPH by myeloperoxidase.

Increased adsorption of cytoplasmic proteins to the erythrocyte membrane in ATP-depleted normal and pyruvate kinase-deficient mature cells and reticulocytes.

How the metabolic defect of pyruvate kinase deficiency (PK(-)) accelerates red blood cell (RBC) destruction is not established, but may be related to RBC membrane abnormalities associated with altered cellular metabolism. Furthermore, it has been shown that PK(-) reticulocytes are especially sensitive to metabolic depletion. Therefore, we compared the membranes of reticulocyte-rich PK(-) RBC, both fresh and ATP depleted, with membranes of fresh and ATP depleted normal mature RBC and reticulocytes. There was no difference between the specific gravity (SG) of the membranes of normal mature RBC (SG 1.152 +/- 0.004) and membranes of reticulocyte-rich RBC from several anemias (SG 1.150 +/- 0.002). However, membranes from fresh, reticulocyte-rich PK(-) RBC were dense with SG of 1.165 +/- 0.004 which correlated with a corresponding increase of protein to lipid phosphorus ratio of 66 +/- 8 micrograms protein/micrograms lipid phosphorus (normal 52 +/- 6 micrograms/micrograms). The membrane density of PK(-) RBC was further increased when the PK(-) RBC ATP was depleted by anaerobic incubation (SG 1.188 +/- 0.004) or cyanide inhibition (SG 1.182 +/- 0.001). When ATP was depleted in normal RBC and in non-PK(-) reticulocytes, corresponding increases in membrane SG occurred. A distinctive 50,000 MW peptide is adsorbed from the cytoplasm to the membranes of reticulocytes (both normal and PK(-) when these cells were depleted of ATP. The increased membrane adsorption of cytoplasmic proteins by PK(-) RBC was not associated with increased RBC calcium uptake, sulfhydryl oxidation, or altered membrane protein phosphorylation. All the observed abnormalities of PK(-) RBC membranes could by reproduced by ATP depletion of reticulocyte-enriched non-PK(-) RBC.

Phospholipid substitution of the purple membrane. The stoichiometry of light-induced proton release by phospholipid-substituted purple membranes

The method of Warren et al. (1974, Proc. Natl. Acad. Sci. U.S. 71, 622–626) was employed to substitute the polar lipids of the purple membrane of Halobacterium halobium by different phosphatidylcholine species. Substitution at pH 6.5 yields proteolipid complexes in the form of bent open sheets which have a protein to lipid phosphorus ratio similar to the natural membrane, i.e. about 1 : 10 (mol/mol). The extent of substitution increases with the length of the fatty acid chain of the phosphatidylcholine used. The spectral properties of bacteriorhodopsin are only slightly affected by substitution of 95% of the lipid, except that the photocycle is slowed down appreciably. Due to this slow rate the M 4 12 intermediate of the cycle accumulates in the light. Associated with this accumulation is a net light-induced proton release, which proved insensitive to uncoupler. A comparison between the net proton release and the amount of M 4 12 accumulated, studied as a function of pH, shows that no fixed stoichiometry exists between the two processes. Phospholipid substitution by egg phosphatidylcholine at pH 7.5 or by egg phosphatidylethanolamine leads to preparations of purple membrane with 15 or 25 mol of phospholipid per mol of bacteriorhodopsin, respectively. These preparations seem to consist of closed membrane structures. They take up protons in the light in an uncoupler-sensitive way.

Radioimmunoassay of pulmonary surface-active material in the tracheal fluid of the fetal lamb.

We measured pulmonary surfactant antigen by radioimmunoassay and phospholipid by lipid phosphorus assay in fluid collected during 12-hour periods from the trachea of lambs in utero between 102 and 147 days of gestation. Both phospholipid and antigen were detectable at 114 days and were present at low concentrations until 137 days. The concentrations then increased rapidly and reached 5- to 10-fold higher concentrations before parturition. The ratio of lipid phosphorus to antigen increased approximately 5-fold as the lungs passed from canalicular to alveolar architecture and approximated the adult ratio only during the alveolar stage of development.

Isolation and characterization of membranes from a hydrocarbon-oxidizing Acinetobacter sp.

Membranes were isolated and purified from nutrient broth-yeast extract- and hexadecane-grown cells of Acinetobacter sp. strain HO1-N. Two membrane fractions were isolated from nutrient broth-yeast extract-grown cells, the cytoplasmic membrane and the outer membrane. In addition to these two membrane fractions, a unique membrane fraction was isolated from hexadecane-grown cells (band 1) and characterized as a lipid-rich, low-density membrane containing high concentrations of hexadecane. The outer membrane preparations of Acinetobacter, obtained from nutrient broth-yeast extract- and hexadecane-grown cells, exhibited a low ratio of lipid phosphorus to protein and contained phospholipase activity and 2-keto-3-deoxyoctulosonic acid. Phosphatidic acid cytidyltransferase, adenosine triphosphatase, and reduced nicotinamide adenine dinucleotide oxidase were recovered almost exclusively in the cytoplasmic membrane fractions. The cytoplasmic membrane fractions contained 20 to 25 polypeptide species on sodium dodecyl sulfate-polyacrylamide gels, and the outer membrane fractions contained 15 to 20 polypeptide species. A major polypeptide species with an apparent molecular weight of approximately 42,000 to 44,000 was found for all outer membrane fractions. The buoyant densities of the cytoplasmic membrane fractions and the outer membrane fractions were closely similar, necessitating their separation by differential centrifugation. Band 1 of hexadecane-grown cells had a ratio of lipid phosphorus to protein that was almost twice that of cytoplasmic membrane and a correspondingly low buoyant density (1.086 g/cm3). Enzyme activities associated with band 1 were identical to those associated with the cytoplasmic membrane. The electrophoretic banding pattern of band 1 was essentially identical to the banding pattern of the cytoplasmic membrane. The phospholipid and neutral lipid compositions of the isolated membrane fractions were determined as qualitatively similar, with significant quantitative differences. The ultrastructure characteristics of the respective membrane fractions were examined by the negative-stain technique.

Mechanism of Chilling Injury in Sweet Potatoes Part V

1. The ratio of the unsaturated C16, C18 and C20 fatty acids to total fatty acids was higher in the crude mitochondrial fraction from chilling-stored sweet potatoes 4 days after transfer to 0°C than from healthy sweet potatoes; and, the difference became greater at periods of 7, 10, and 14 days. However, this difference was shown to be mainly due to the decrease during chilling storage in contamination with lauric acid, isopalmitic acid (presumable) and erucic acid (presumable) contained in the latex body fraction. 2. There were no significant changes in the composition and amounts of fatty acids in the 0_??_700×g fraction, the microsomal fraction, and the supernatant fraction, when sweet potatoes were given a chilling treatment. 3. The ratio of C16, C18 and C20 unsaturated fatty acids to total fatty acids in the pure mitochondrial fraction from sweet potatoes was not changed significantly as a result of chilling storage. However, the ratio of lipid-phosphorus (lipid-P) to acid insoluble nitrogen (acid insol.-N) decreased during chilling storage, and the density of the mitochondria was slightly heavier as revealed by sucrose density gradient centrifugation. 4. The composition of fatty acids, the ratio of lipid-P to acid insol.-N, and the density of the pure mitochondrial fraction from white potatoes was not distinctly changed as a result of chilling storage. 5. Contrary to previous reports, white potato, a temperate-zone plant, had a lower ratio of unsaturated fatty acids to total fatty acids in the pure mitochondrial fraction than in the case of sweet potato, a tropical plant.

Mechanism of Chilling Injury in Sweet Potatoes

1. The ratio of the unsaturated C16, C18 and C20 fatty acids to total fatty acids was higher in the crude mitochondrial fraction from chilling-stored sweet potatoes 4 days after transfer to 0°C than from healthy sweet potatoes; and, the difference became greater at periods of 7, 10, and 14 days. However, this difference was shown to be mainly due to the decrease during chilling storage in contamination with lauric acid, isopalmitic acid (presumable) and erucic acid (presumable) contained in the latex body fraction.2. There were no significant changes in the composition and amounts of fatty acids in the 0 ~ 700 × g fraction, the microsomal fraction, and the supernatant fraction, when sweet potatoes were given a chilling treatment.3. The ratio of C16, C18 and C20 unsaturated fatty acids to total fatty acids in the pure mitochondrial fraction from sweet potatoes was not changed significantly as a result of chilling storage. However, the ratio of lipid-phosphorus (lipid-P) to acid insoluble nitrogen (acid ins...

Biochemical aspects of the visual process: XIII. The role of phospholipids in cattle rhodopsin studied with phospholipase C

The importance of the phospholipids present in cattle rod outer segments for the spectral integrity of rhodopsin was studied. The molar ratio of lipid phosphorus to retinaldehyde bound in rhodopsin could be reduced from 87 to 4 by means of treatment with phospholipase C from Bacillus cereus without affecting the spectral integrity of the rhodopsin. Hexane extraction of the phospholipase C-treated material did not further reduce the lipid phosphorus to retinaldehyde ratio, but did remove diglycerides arising from the hydrolyzed phospholipids. The photolytic properties of phosphlipase C-treated rhodopsin remained intact also during the hexane extraction. From this it was concluded that neither the polar moiety nor the diglyceride part of 95% of the phospholipids in the rod outer segments are essential for the spectral integrity of rhodopsin. Quantitative analysis of the phospholipids present in the phospholipase C-treated, hexane-extracted preparation showed that they consisted of 1.6 mole phosphatidyl serine, 0.4 mole diphosphatidyl glycerol, 0.6 mole sphingomyeline, and 0.1 mole phosphatidyl ethanolamine per mole of retinaldehyde. These findings rule out the possibility that the retinaldehyde group in rhodopsin is linked to phosphatidyl ethanolamine.

Serum protein-bound iodine and serum lipid changes in the thyroidectomized, hypophysectomized, castrated and adrenalectomized baboon (Papio ursinus).

SUMMARY Thyroidectomy, hypophysectomy, pituitary stalk section and thyro-hypophysectomy cause a rapid decline in the serum protein-bound iodine (PBI) of the baboon. A low PBI level was, however, persistently maintained in serum from thyroidectomized baboons. The serum PBI of castrated baboons remained normal, whereas a significant increase was observed after adrenalectomy. The mean serum lipids and cholesterol:lipid phosphorus ratio were elevated in thyroidectomized baboons and tended to return to normal in cases of thyroid nodule regeneration. After hypophysectomy and pituitary stalk section the serum total cholesterol was higher than that of the normal adult baboon, while thyro-hypophysectomy resulted in a significant decrease of the total lipids, total cholesterol and lipid phosphorus. These low lipid concentrations in the absence of the pituitary and thyroid were maintained more consistently than in the normal thyroidectomized or hypophysectomized baboon. Castration in the baboon led to a significant rise of all lipid fractions under investigation. Hypophysectomy in the baboon caused an increased sensitivity to adrenocorticotrophic hormone and cortisone, as judged by the serum lipid response. Such an increased sensitivity seemed to be absent in the thyro-hypophysectomized baboon.

The effect of cortisone on the serum lipids and on the development of experimental cholesterol atherosclerosis in the rabbit.

An experiment was performed to determine the effect of cortisone on the serum lipids and on the development of experimental cholesterol atherosclerosis in the rabbit. Litter mate rabbits of the same sex were employed; both sexes were represented in the experiment. The report is based upon four experimental groups comprising (1) 12 rabbits fed cholesterol and treated with cortisone vehicle; (2) 12 rabbits fed cholesterol and treated daily with cortisone; (3) 11 rabbits treated with cortisone; and (4) 7 rabbits that received cortisone vehicle. It was observed that: (1) There was less aortic atherosclerosis in the cholesterol-fed cortisone-treated rabbits as judged by both morphological and chemical means than in the rabbits fed cholesterol without cortisone treatment. (2) Cortisone depressed appreciably the hypercholesterolemia resulting from the feeding of cholesterol to rabbits. (3) Cortisone treatment caused a moderate hypercholesterolemia in normal rabbits. (4) Cortisone caused a moderate increase in serum lipid phosphorus equal to that produced by cholesterol feeding alone. (5) The combination of cholesterol feeding and cortisone did not result in a higher phospholipidemia than either one of these agents alone. (6) Cortisone caused a great increase in serum-neutral fat; it was not apparent whether cholesterol feeding affected the neutral fat lipemia due to cortisone treatment alone. (7) The total cholesterol to lipid phosphorus ratio was about normal in the rabbits that received cortisone only. It was doubled in the animals receiving both cholesterol and cortisone, and it was increased about four times in those that received only cholesterol. The significance of the alterations in the serum lipids induced by cortisone is discussed in relation to the inhibition of the development of aortic atherosclerosis that occurred in the cholesterol-fed rabbits treated with cortisone.