References: Lecithin
J Biol Chem. 1989 Mar 15;264(8):4450-5.
Lipid synthesis in permeabilized cultured rat hepatocytes.
Mayorek N, Bar-Tana J.
Department of Biochemistry, Hebrew University, Hadassah Medical School, Jerusalem, Israel.
Hepatic lipid synthesis was verified and studied in lysolecithin-permeabilized cultured rat hepatocytes and compared to that of intact liver cells. Triacylglycerol synthesis in permeabilized cells incubated in the presence of glycerol 3-phosphate and long chain fatty acids approached that of intact hepatocytes. Similarly, phosphatidylcholine synthesis in permeable cells incubated in the presence of exogenous CDP-choline was similar to that of intact hepatocytes and at the expense of microsomal neutral lipid synthesis. Phosphatidic acid accumulation in lysolecithin-permeabilized liver cells was remarkably increased as compared to that of intact cells, and its synthesis was mostly accounted for by the activity of mitochondrial glycerol-3-phosphate acyltransferase. Mitochondrial-generated phosphatidate was found to migrate to the endoplasmic reticulum, thus establishing a novel lipid esterification pathway which begins in mitochondrial glycerol 3-phosphate acylation and results in microsomal triacylglycerol and phospholipid synthesis. The free access of permeabilized liver cells to substrates and modulators of lipid synthesis, while maintaining an overall synthetic pattern similar to that of intact hepatocytes, makes them a system of choice for studying hepatic lipid synthesis in general and the microsomal/mitochondrial distribution of fluxes in particular.
Laxative online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2925651&dopt=Abstract lecithin
J Biol Chem. 1989 Mar 15;264(8):4628-35.
Properties of lipid complexes with amphipathic helix-forming peptides. Role of distribution of peptide charges.
Epand RM, Surewicz WK, Hughes DW, Mantsch H, Segrest JP, Allen TM, Anantharamaiah GM.
Department of Biochemistry, McMaster University Health Sciences Centre, Hamilton, Ontario.
The peptides [Glu1,8,Leu11,17] 18A and [Glu4,9,Leu11,17] reverse-18A are 18-residue peptides designed to form amphipathic helices with opposite charge distribution; [Glu1,8,Leu11,17] 18A having positively charged residues at the hydrophobic/hydrophilic interface. Both [Glu1,8,Leu11,17] 18A and [Glu4,9,Leu11,17] reverse-18A strongly disrupt the bilayer structure as indicated by the relatively narrow lipid 1H and 31P NMR peaks. In addition, the 1H chemical shift of the quaternary ammonium methyl groups indicates that [Glu1,8,Leu11,17] 18A forms smaller lipoprotein particles with dimyristoylphosphatidylcholine (DMPC) than does [Glu4,9,Leu11,17] reverse-18A. However, motional properties of the lipid head group indicate that no specific salt bridges are formed between the phospholipid head group and the side chains of polar amino acids of either of the two peptides. In addition, the acyl chain conformation for the DMPC complexes with [Glu1,8,Leu11,17] 18A and with [Glu4,9,Leu11,17] reverse-18A are indistinguishable by the criterion of IR spectroscopy. The 2H linewidth of the solvent 2H2O remains narrower in frozen solutions of the DMPC-[Glu1,8,Leu11,17] 18A complexes suggesting the presence of more unfrozen bound water in this case. The two peptides exhibit many similarities in their interaction with lipids. However, [Glu1,8,Leu11,17] 18A can more readily lyse vesicles and activate lecithin:cholesterol acyltransferase. These differences do not appear to result from differences in specific charge interactions between the lipid and peptide but may be manifested through differences in hydration properties.
Laxative online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2925658&dopt=Abstract lecithin
Gene. 1993 Jun 30;128(2):295-9.
Baboon lecithin cholesterol acyltransferase (LCAT): cDNA sequences of two alleles, evolution, and gene expression.
Hixson JE, Driscoll DM, Birnbaum S, Britten ML.
Department of Genetics, Southwest Foundation for Biomedical Research, San Antonio, TX 78228-0147.
Lecithin cholesterol acyltransferase (LCAT) is a key enzyme of cholesterol metabolism that catalyzes esterification of cholesterol for packaging in high-density lipoprotein (HDL) particles. In this study, we cloned and sequenced LCAT cDNA from baboon, a nonhuman primate model of atherosclerosis. LCAT sequences have been highly conserved over approximately 25 million years since the divergence of the baboon and human lineages. The baboon and human sequences are 97% identical at the nucleotide (nt) level and 98% identical at the amino acid (aa) level. Only 18% of the nt substitutions change the aa sequence (nonsynonymous substitutions). The substitutions between baboon and human LCAT do not alter key functional sites including the interfacial substrate active site, asparagine-linked glycosylation sites, or sites at which rare mutations cause human familial LCAT deficiencies. We also sequenced LCAT cDNA for a less common allele that is associated with higher LCAT activities and altered lipoprotein phenotypes. There were no sequence differences between the two alleles, which suggests that genotypic effects are most likely due to allelic differences in gene expression. The tissue specificity of LCAT expression was investigated using an RNase protection assay calibrated with known amounts of synthetic human LCAT RNA. In a survey of baboon tissues, the highest levels of LCAT mRNA were found in the cerebellum and liver and trace amounts in the ileum, spleen and cerebral cortex.
Laxative online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8514197&dopt=Abstract lecithin
Lecithin online literature
Buy Rx Online || Hair Million herbal formula for hair loss and hair growth || Hair Million, excellent herbal formula, wards off hair loss and promotes hair growth || Buy Tramadol || Dream Pharmaceuticals Online Pharmacy: Buy Rx Online || Lecithin product online guide ||