PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “STEARIC ACID”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 325 records · Page 18Linked to original sources
PubMed1998

Ribozymes targeted to stearoyl-ACP delta9 desaturase mRNA produce heritable increases of stearic acid in transgenic maize leaves.

Ribozymes are RNAs that can be designed to catalyze the specific cleavage or ligation of target RNAs. We have explored the possibility of using ribozymes in maize to downregulate the expression of the stearoyl-acyl carrier protein (Delta9) desaturase gene. Based on site accessibility and catalytic activity, several ribozyme constructs were designed and transformed into regenerable maize lines. One of these constructs, a multimer hammerhead ribozyme linked to a selectable marker gene, was shown to increase leaf stearate in two of 13 maize lines. There were concomitant decreases in Delta9 desaturase mRNA and protein. The plants with the altered stearate phenotype were shown to express ribozyme RNA. The ribozyme-mediated trait was heritable, as evidenced by stearate increases in the leaves of the R1 plants derived from a high-stearate line. The increase in stearate correlated with the presence of the ribozyme gene. A catalytically inactive version of this ribozyme did not produce any significant effect in transgenic maize. This is evidence that ribozymes can be used to modulate the expression of endogenous genes in maize.

Amino Acid Sequence↗
PubMed1998

The signature 10-hydroxy stearic acid thought to correlate with infectivity in oocysts of Cryptosporidium species is an artifact.

Heating or freezing leads to loss in infectivity of oocysts of Cryptosporidium parvum toward neonatal BALB/c mice and is reflected in the profile of the polar lipid fatty acids. Upon loss of infectivity, the ratio of polar lipid to neutral lipid fatty acid decreased and the relative proportions of 18:1n-9 also decreased; proportions of 18:2n-6 and 20:5n-6 increased, whereas the proportions of 16:0 remained constant with freezing. During these investigations, a novel fatty acid, 10-OH 18:0, was discovered in the glycolipid fraction. The identification of a fatty acid unique to species of Cryptosporidium was thought to provide a specific biomarker for this organism. Cryptosporidium also demonstrated fluctuations in absolute quantities of 10-OH 18:0 with events that lead to loss of infectivity. This led to the presumed correlation of this biomarker with infectious Cryptosporidium. The 10-OH 18:0 was putatively localized at the sn-2 position of phosphatidylethanolamine. High-performance liquid chromatography/electrospray ionization mass spectrometry revealed that the 10-OH 18:0 existed principally in the free fatty acid form. Herein, we establish that the free fatty acid 10-OH 18:0 was, in actuality, an artifact of the procedures for sample preparation.

Animals↗
PubMed1982

[Absorption study of 3H-stearic acid in the rat small intestine using electron microscopic autoradiography].

Using electron microscope autoradiography evidence was provided on the space time character of the absorption, resynthesis, transfer and exocytosis of lipids in the form of chylomicrons; this evidence correlating with data on distribution in the subcellular compartments of epithelial cells of the intestine. The majority of fatty acid enters the lymph in the form of resynthesized lipids. Part of fatty acid is transported from the enteral environment to the internal one, escaping from the stages of esterification and triglyceride and chylomicron formation in the endoplasmic reticulum and Golgi apparatus.

Animals↗
PubMed1969

Effects of polypeptide and protein hormones on lipid monolayers. I. Effect of insulin and parathyroid hormone on monomolecular films of monooctadecyl phosphate and stearic acid.

Insulin in low concentrations inhibits the uptake of Ca(++) by the monooctadecyl (stearyl) phosphate monolayer (at air-water interface) and facilitates the release of Ca(++) adsorbed to the monolayer. These effects of insulin are more pronounced at higher insulin concentrations. Evidence is presented that a relatively intact insulin molecule competes with Ca(++) for the free phosphate group of the monolayer. Albumin has a slight inhibitory action on calcium uptake and parathyroid hormone has no observable action on calcium uptake or release.

Albumins↗
PubMed2006

Thermodynamics of the interaction of globular proteins with powdered stearic acid in acid pH.

Adsorption isotherms of different globular proteins and gelatin on strearic acid particles have been studied as a function of biopolymer concentration, ionic strength of the medium, and temperature. The effect of neutral salts including CaCl2, Na3PO4, and urea on the adsorption isotherms has been also investigated. It is observed that the extent of adsorption (Gamma2(1)) increases in two steps with the increase of biopolymer concentration (C2) in the bulk. Gamma2(1) increases with an increase of C2 until a steady maximum value Gamma2(m) is reached at a critical concentration C2(m). After initial saturation, Gamma2(1) again increases from Gamma2(m) without reaching any limiting value due to the surface aggregation of the protein. The values of the standard free energy change for adsorption have been calculated on the basis of the Gibbs equation. The standard entropy and enthalpy changes are also calculated.

Adsorption↗