Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.1.5 (neuropathy target esterase)
 1,070 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rat pancreas presents a spontaneous phospholipase A activity which appears before trypsin activation at optimal pH 6.5. The responsible enzyme is independent of pancreatic prophospholipase A, as can be seen through experiments done in the presence of trypsin inhibitors. On the other hand, this enzyme is distinct from excretory phospholipase which is more active and whose optimal pH is 8.8. Thermostability and insensibility of spontaneously active phospholipase A to DFP differentiate it from lipase, carboxyl-esterhydrolase and lysophospholipase, respectively.
 ...
PMID:[Spontaneous phospholipase A activity of rat pancreatic homogenates]. 1 5

Phospholipase activities of rat intestinal mucosa homogenate have been determined from lysophosphatidylcholines [14C] and phosphatidylcholines [-3H-14C]. In the presence of phosphatidylcholines, at pH 6.5, the homogenate has a phospholipase B activity. At pH 8.5, a phospholipase A2 activity was shown. In the presence of lysophospatidylcholines, at pH 6.5, we notice a lysophospholipase A1 activity. A kinetic study of the reactions allows us to separate the activity B into a phospholipase A2 activity and a lysophospholipase A1 activity. Thus, it appears that the total phospholipase activity of rat intestinal mucosa would results from a phospholipase A2 activity and a lysophospholipase A1 activity.
 ...
PMID:[Phospholipase of rat intestine: mode of action]. 1 16

In mammalian cells the catabolism of membrane phosphoglycerides proceeds probably entirely through a deacylation pathway catalysed by phospholipase A and lysophospholipase (Wise & Elwyn, 1965). In the initial attack of diacylphosphoglycerides by phospholipase A two enzymatic activities with different positional specificities have been distinguished: phospholipase A1 (phosphatidate 1-acyl hydrolase EN 3.1.1.32) and phospholipase A2 (phosphatidate 2-acyl hydrolase EN 3.1.1.4) (Van Deenen & De Haas, 1966). Studies on these intracellular phospholipases were mainly concerned with their subcellular localization. Only occasionally more detailed enzymatic investigations have been conducted on them, in contrast to export phospholipases e.g. from snake venom, bee venom and porcine pancreas, which have been extensively investigated (Brockerhoff & Jensen 1974a). In a previous paper (De Wolf et al., 1976a), the presence of phospholipase A1 and phospholipase A2 activities in bovine thyroid was demonstrated, using 1-[9, 10-3H] stearoyl-2-[1-14C] linoleyl-sn-glycero-3-phosphocholine as a substrate. Optimal activity was observed in both instances at pH 4. Addition of the anionic detergent sodium taurocholate increased the A2 type activity and decreased the A1 type activity suggesting the presence of different enzymes. The lack of influence of Ca2+-ions and EDTA and the acid pH optima could suggest lysosomal localization. In this paper the subcellular distribution of both acid phospholipase activities is described as well as a purification scheme for phospholipase A1. Some characteristics of the purified enzyme preparation are discussed.
 ...
PMID:Lipolytic enzymes in bovine thyroid tissue. I. Subcellular localization, purification and characterization of acid phospholipase A1. 8 59

1. A pure lipid acyl-hydrolase was prepared from potato tubers by acetone precipitation, Sephadex G-100 and DEAE-Sephadex A-50 column chromatography, and by electrofocusing. 2. The purified enzyme was an acidic protein of pI 5.0 and molecular weight of about 70 000. Km values were 0.38 mM for monogalactosyldiacylglycerol and 1.7 mM for phosphatidylcholine. 3. The hydrolytic activity of the enzyme on different substrates was determined. The relative rates were acylsterylglucoside greater than monogalactosyldiacylglycerol greater than monogalactosylmonoacylglycerol greater than digalactosyldiacylglycerol greater than diagalactosylmonoacylglycerol, while the rates for phospholipids were lysophosphatidylcholine greater than phosphatidylcholine greater than lysophosphatidylethanolamine greater than phosphatidylethanolamine. 4. Analyses of enzymatic hydrolysis products suggested that a single enzyme had both galactolipase and phospholipase activities, and for the phospholipids it showed activities similar to phospholipase B and glycerylphosphorylcholine diesterase. 5. A competitive relation was found between monogalactosyldiacylglycerol and phosphatidylcholine as substrates of the enzyme, indicating that the active sites for both substrates may be the same. 6. It was suggested that histidine and probably serine residues were important to the enzymic activity, and that a tyrosine residue might be involved in the activity as an accessory component.
 ...
PMID:Purification and properties of a lipid acyl-hydrolase from potato tubers. 23 65

The total homogenate of rat intestine is devoid of C or D phospholipase activity. At pH 6,5 in the presence of phosphatidylcholines, it exhibits a B phospholipase activity and in the presence of exogen lysophosphatidylcholines an A1 lysophospholipase activity. At pH 8,5 the intestinal mucous membrane of a rat shows an isolated A2 phospholipase activity.
 ...
PMID:[Specificity of action of phospholipases of rat intestinal mucosa]. 24 May 9

Phospholipase A and lysophospholipase have been identified as the enzymes responsible for phospholipid hydrolysis by Candida albicans. The method used to identify and measure the activity of these enzymes is described, and the probable significance of phospholipase in the invasion of the epithelium by Candida albicans discussed.
 ...
PMID:Phospholipase activity in Candida albicans. 33 24

An enzyme with phospholipase Al activity was purified some 500-fold from Escherichia coli cell homogenates. Lipase, phospholipase A2, and lysophospholipase copurified with phospholipase A1 and the four activities displayed similar susceptibility to heat treatment. The phospholipase A and lipase activities were recovered in a single band when partially purified preparations were subjected to SDS gel electrophoresis. Phospholipase, lysophospholipase, and lipase all required Ca2+ for activity. Phosphatidylcholine, phosphatidylethanolamine, and their lyso analogues were all hydrolysed at equivalent rates and these were substantially greater than the rate of methylpalmitate or tripalmitoylglycerol hydrolyses under similar incubation conditions. Evidence for a direct but slow hydrolysis of the ester at position 2 of phosphoglyceride was obtained; however, release of fatty acid from this position is mostly indirect involving acyl migration to position 1 and subsequent release of the translocated fatty acid. Escherichia coli, therefore, appears to possess a lipolytic enzyme of broad substrate specificity acting mainly at position 1 but also at position 2 of phosphoglycerides and on triacylglycerols and methyl fatty-acid esters.
 ...
PMID:Partial purification of a lipolytic enzyme from Escherichia coli. 35 85

The effects of some antibiotics on activities of phospholipase A2, B and C were investigated in vitro. Tetracyclines, macrolides, chloramphenicol and carbenicillin inhibited the activity of Crotalus adamanteus phospholipase A2 towards phospholipids of egg-yolk emulsions. When the ability to inhibit the activity of Penicillium notatum phospholipase B towards mixed micelles of phosphatidylcholine and Triton X-100 was investigated, polymyxin B was found to be inhibitory while chloramphenicol and carbenicillin were found to stimulate the activity of the phospholipase. The activity of Bacillus cereus phospholipase C towards the mixed micelles was inhibited by bleomycin, oleandomycin and chloramphenicol.
 ...
PMID:In vitro actions of some antibiotics on phospholipases. 54 Dec 66

The Clara cell of the bronchiole is unique to the lung; the cell's function is not clear. The localization of the lipid-hydrolase enzymes phospholipase, lysophospholipase, and lipase was examined ultrastructurally in the Clara cell of the rat bronchiole. The secretory granules of the Clara cell showed a strong reaction of lysophospholipase and a weak reaction of lipase. Phospholipase activity was not detected intracellularly. These findings suggest that the Clara cell secretes lipase-phospholipase into the bronchiolar lumen, thus catabolizing the pulmonary surfactant phospholipids.
 ...
PMID:Ultrastructural localization of phospholipases in the Clara cell of the rat bronchiole. 58 34

The positional specificity of the phospholipase A in human gallbladder epithelium was studied by using biosynthetically radioabeled diacylphosphoglycerides as substrates. Diacylphosphoglyceride in 14C-palmitic acid-labeled, autoclaved E.coli was hydrolyzed under the formation of monoacylphosphoglyceride and fatty acid that were both radiolabled. In contrast, diacylphosphoglyceride in 14C-oleate-labeled bacteria was hydrolyzed so as to give radiolabel in the fatty acid only. Since 14C-palmitate occupies predominantly the 1-acyl position and 14C oleate the 2-acyl position of the major E. coli diacylphosphoglycerides, these findings suggest that: 1) the phospholipase attacks and 2-position of diacylphosphoglycerides, and 2) a complete deacylation of diacylphosphoglycerides in the gallbladder wall is brought about by the combined action of phospholipase A2 and lysophospholipase, the latter being able to hydrolyze the 1-acyllysophosphoglyceride. It appears, therefore, that the biochemical preequisites for a local formation and degreadation of lysolecithin in the gallbladder itself are met by the positional specificity of theenzymes present. This finding further substantiates the hypothesis that lysolecithin is an adjustable mediator of aseptic cholecystitis.
 ...
PMID:The prerequisites for local lysolecithin formation in the human gallbladder. II. Studies on the positional specificity of the phospholipase A activity. 67 50


1 2 3 4 5 6 7 8 9 10 Next >>