Abstract：
:Phospholipase was isolated (in two fractions) from Vipera palestinae venom and it was shown to possess phospholipase A activity (hydrolyzing diacyl-sn-glycerophosphorylcholines, e.g., lecithin, in the 2-position) as well as lysophospholipase (phospholipase B) activity (hydrolyzing 1-monoacyl-sn-glycerophosphorylcholines, e.g., lysolecithin, yielding free fatty acid and glycerophosphorylcholine). Each of the two purified enzyme fractions was homogeneous as judged by electrophoresis on acrylamide gel and by immunodiffusion and immunoelectrophoresis, and both had essentially equal activities. The ratio of the specific activity, at various purification stages, to the specific activity of the whole venom was the same for A activity (substrate lecithin) as for B activity (substrate lysolecithin). The enzyme has a molecular weight of 16,000, six S-S bridges, and no free thiol groups. At pH 7, dimerization was observed in the ultracentrifuge. A dissociation constant of about 10(-5) m was estimated. The amino acid composition for both fractions (140 amino acid residues) was found to be essentially the same. The A activity had a pH optimum at 9; B activity was low at this pH but increased steadily beyond pH 10.5. For the hydrolysis of lysolecithin the Lineweaver-Burk plot was found to be linear, giving K(m) = 1.1 mm and k(cat) = 0.55 sec(-1) at 37 degrees C and pH 10. 2-Deoxylysolecithin was also hydrolyzed by the enzyme at pH 10, with k(cat) = 0.01 sec(-1) (zero-order kinetics in the range 0.5-2.5 mm). For lecithin these constants could not be determined, but at 0.25 mm substrate the hydrolysis rate (at pH 9) of lecithin was about 1000 times the hydrolysis rate of lysolecithin (at pH 10).
journal_name
J Lipid Resjournal_title
Journal of lipid researchauthors
Shiloah J,Klibansky C,de Vries A,Berger Asubject
Has Abstractpub_date
1973-05-01 00:00:00pages
267-78issue
3eissn
0022-2275issn
1539-7262journal_volume
14pub_type
杂志文章abstract：:The objective of this study was to establish a new lipoprotein lipase (LPL) and hepatic lipase (HL) activity assay method. Seventy normal volunteers were recruited. Lipase activities were assayed by measuring the increase in absorbance at 546 nm due to the quinoneine dye. Reaction mixture-1 (R-1) contained dioleoylgly...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M700528-JLR200
更新日期：2008-07-01 00:00:00
abstract：:The bioactive molecule sphingosine 1-phosphate (S1P) is abundantly stored in platelets and can be released extracellularly. However, although they have high sphingosine (Sph) kinase activity, platelets lack the de novo sphingolipid biosynthesis necessary to provide the substrates. Here, we reveal a generation pathway ...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M500268-JLR200
更新日期：2005-11-01 00:00:00
abstract：:Bile salts of the coelacanth, Latimeria chalumnae, Smith, have been analyzed and shown to have three bile alcohols, latimerol, 5 alpha-cyprinol, and 5 alpha-cholestane-3 beta, 7 alpha,-12 alpha,25,26-pentol, two C24 bile acids, chenodeoxycholic acid and cholic acid, one C26 bile acid, probably 3 beta, 7 alpha, 12 alph...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1984-12-01 00:00:00
abstract：:Increased plasma concentrations of apolipoprotein A-IV (apoA-IV) in chronic renal disease suggest a metabolic role of the kidney for this antiatherogenic protein. Therefore, we investigated patients with various forms of proteinuria and found increased serum concentrations of apoA-IV in 124 nephrotic patients compared...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M600178-JLR200
更新日期：2006-09-01 00:00:00
abstract：:The total nitrogen and L-hydroxyproline concentrations of two intra-abdominal and two subcutaneous sites of adipose tissue were measured in male and female Wistar rats. At 100 g body weight the nitrogen concentration of intra-abdominal adipose tissue was slightly lower than that of subcutaneous adipose tissue. As age ...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1970-07-01 00:00:00
abstract：:We have recently reported that the human apolipoprotein A-I (apoA-I) and apolipoprotein C-III (apoC-III) genes are physically linked and that the presence of a DNA insertion in the apoA-I gene is correlated with apoA-I-apoC-III deficiency in patients with premature atherosclerosis. In addition, the presence of a polym...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1985-04-01 00:00:00
abstract：:Lipoprotein lipase (LPL) hydrolyzes circulating lipoprotein triglyceride molecules while it is associated with the luminal surface of capillary endothelial cells. The precise molecular mechanism by which LPL attaches to these cells is unknown. LPL and a number of other molecules, including growth factors and clotting ...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1993-11-01 00:00:00
abstract：:Apheresis is a treatment option for patients with severe hypercholesterolemia and coronary artery disease. It is, however, unknown whether such therapy changes kinetic parameters of lipoprotein metabolism, such as apolipoprotein B (apoB) secretion rates, conversion rates, and fractional catabolic rates (FCR). We studi...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1996-11-01 00:00:00
abstract：:We used [2-13C1]glycerol to characterize very low density lipoprotein (VLDL)-triglyceride kinetics and intrahepatic glycerol metabolism in normal men (n = 4) after alcohol (EtOH) ingestion. [2-13C1]glycerol was infused before and after the consumption of 48 g EtOH or a placebo. Three additional subjects also received ...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1998-12-01 00:00:00
abstract：:Exosomes are bioactive vesicles released from multivesicular bodies (MVB) by intact cells and participate in intercellular signaling. We investigated the presence of lipid-related proteins and bioactive lipids in RBL-2H3 exosomes. Besides a phospholipid scramblase and a fatty acid binding protein, the exosomes contain...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M003657
更新日期：2010-08-01 00:00:00
abstract：:The ability to exogenously present cell-surface receptors in high-affinity conformations in a synthetic system offers an opportunity to provide host cells with protection from pathogenic toxins. This strategy requires improvement of the synthetic receptor binding affinity against its native counterpart, particularly w...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M007401
更新日期：2010-09-01 00:00:00
abstract：:Adipose tissue was shown to contain 0.6-1.6 mg of cholesterol per gram wet weight. When expressed per unit of protein or organ mass, fat tissue contains more cholesterol than most other organs or membranes. The cholesterol content of fat tissue increased with the age and weight of the rat. Over 95% of adipose tissue s...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1973-05-01 00:00:00
abstract：:Three mammalian cell lines were examined for their ability to metabolize the regulatory oxysterol, 25-hydroxycholesterol, and derepress 3-hydroxy-3-methylglutaryl CoA reductase. In mouse L cell fibroblasts reductase activity was restored with the concomitant metabolism of 25-hydroxycholesterol via side-chain hydroxyla...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1989-06-01 00:00:00
abstract：:Isolated etioplasts from 8-day-old dark-grown pea seedlings incorporated [1-(14)C]acetate into lipid at a relatively low rate. Plastids from seedlings that had been illuminated for at least 2 hr showed an enhanced incorporation provided the plastids were illuminated during incubation with the labeled acetate. Dark inc...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1973-11-01 00:00:00
abstract：:The human retina is well-known to have unique lipid profiles enriched in long-chain polyunsaturated fatty acids (LC-PUFAs) and very long-chain polyunsaturated fatty acids (VLC-PUFAs) that appear to promote normal retinal structure and function, but the influence of diet on retinal lipid profiles in health and disease ...
journal_title：Journal of lipid research
pub_type： 临床试验,杂志文章
doi：10.1194/jlr.P065540
更新日期：2016-03-01 00:00:00
abstract：:Analyses have been made of glycosphingolipids from visceral organs and brain of a patient with an unusual lipid storage disorder diagnosed initially as classical Tay-Sachs disease. Levels of the lipids from fresh-frozen sections of gray and white matter, kidney, spleen, liver, and heart from this patient were compared...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1972-01-01 00:00:00
abstract：:The methanolyzed lipids of the extreme halophile, Halobacterium cutirubrum, were separated into glycerol diether and glycerol monoether fractions. The diether was shown by synthesis to be 2,3-di-O-(3'R,7'R,11'R,15'-tetramethylhexadecyl)-sn-glycerol. The monoether fraction was separated by thin-layer chromatography on ...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1968-11-01 00:00:00
abstract：:Four groups of 20 weanling swine each were fed either (a) basal diet, (b) basal plus hydrogenated fat (13% trans), (c) basal plus hydrogenated fat (13% trans) and 0.4% cholesterol, or (d) basal plus beef tallow (all cis). After six months of feeding, the animals were killed and the blood and aortas were removed. Very ...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1977-03-01 00:00:00
abstract：:The essential fatty acid DHA (22:6, omega-3 or n-3) is enriched in and required for the membrane biogenesis and function of photoreceptor cells (PRC), synapses, mitochondria, etc. of the CNS. PRC DHA becomes an acyl chain at the sn-2 of phosphatidylcholine (PC), amounting to more than 50% of the PRC outer segment phos...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.TR120001137
更新日期：2020-10-26 00:00:00
abstract：:Long-chain acyl-CoA synthetases (ACSLs) catalyze the thioesterification of long-chain FAs into their acyl-CoA derivatives. Purified ACSL4 is an arachidonic acid (20:4)-preferring ACSL isoform, and ACSL4 is therefore a probable regulator of lipid mediator production in intact cells. Eicosanoids play important roles in ...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M013292
更新日期：2011-04-01 00:00:00
abstract：:Due to conflicting reports concerning the relationship between phospholipid transfer protein (PLTP) activity and mass in plasma, the protein concentration and activity of PLTP were assessed in fractions isolated by fast protein liquid chromatography from the plasma of healthy normolipidemic individuals. Using both pol...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：2002-02-01 00:00:00
abstract：:The sequences of the plasma apolipoproteins have a high degree of internal homology as they contain several 22-mer internal repeats. These amphipathic helical repeats are considered as the structural and functional units of this class of proteins. We proposed that the 22-mer repeats of the plasma apolipoproteins consi...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1995-08-01 00:00:00
abstract：:We report the characterization of eight mutations of sterol 27-hydroxylase gene (CYP27) in five Italian patients with cerebrotendinous xanthomatosis, who were found to be compound heterozygotes. Four mutations (C --> T at nt 45 of exon 4, G(+1) --> A in intron 6, G(+5) --> T in intron 7, and G(-1) --> A in intron 7) a...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1997-11-01 00:00:00
abstract：:Dietary n-3 long-chain PUFAs (LC-PUFAs) are associated with improvement in the parameters of the metabolic syndrome (MetS). Glucokinase regulatory protein (GCKR) is a key protein regulating intracellular glucose disposal. Our aim was to investigate: i) the relationship between the GCKR rs1260326 (Pro446Leu) polymorphi...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M057570
更新日期：2015-09-01 00:00:00
abstract：:Oxidized forms of cholesterol (oxysterols) are present in atherosclerotic lesions and may play an active role in lesion development. For example, 7-ketocholesterol (7KC) inhibits cholesterol efflux from macrophage foam cells induced by apolipoprotein A-I (apoA-I). Such oxysterols may promote foam cell formation in ath...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1999-09-01 00:00:00
abstract：:Spectrophotometric techniques for determining the activities of lipases, lysophospholipases, and phospholipases are reviewed. These methods involve the use of thioester substrate analogs as well as omega-nitrophenyl derivatives of the corresponding lipids. The most promising results are obtained with the thioester sub...
journal_title：Journal of lipid research
pub_type： 杂志文章,评审
doi：
更新日期：1984-12-15 00:00:00
abstract：:Rates of conversion of alpha-linolenic acid (alpha-LNA, 18:3n-3) to docosahexaenoic acid (DHA, 22:6n-3) by the mammalian brain and the brain's ability to upregulate these rates during dietary deprivation of n-3 polyunsaturated fatty acids (PUFAs) are unknown. To answer these questions, we measured conversion coefficie...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：10.1194/jlr.M600549-JLR200
更新日期：2007-05-01 00:00:00
abstract：:Structurally specific very low density lipoprotein (VLDL) particles are presumed to redirect VLDL uptake during yolk deposition. Egg production is an energy intensive process, but energy excess negatively affects egg production. This study sought to determine whether overfeeding changed hen lipoprotein profiles, and i...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1994-08-01 00:00:00
abstract：:Lymph fistula rats with either biliary fistula or pancreaticobiliary fistula were used to measure coenzyme A-independent mucosal cholesterol esterifying activity in the presence and absence of pancreatic exocrine secretion. Efficiency of pancreatic diversion was verified to minimize contamination of mucosal homogenate...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1981-01-01 00:00:00
abstract：:Six African green monkeys were labeled intravenously with [1,2-(3)H]cholesterol while consuming a cholesterol-free liquid formula diet. The plasma cholesterol specific activity was compared with the specific activity of the biliary cholesterol and bile acids and with the fecal neutral steroids in order to determine wh...
journal_title：Journal of lipid research
pub_type： 杂志文章
doi：
更新日期：1980-09-01 00:00:00
