Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.4.3 (phospholipase C)
 18,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of several kinds of carbohydrate oxidase, SH-inhibitors and some other chemical reagents on the activities of von Willebrand factor, factor VIII procoagulant and factor VIII-related antigen were studied. Factor VIII procoagulant and von Willebrand factor activities were both inhibited by galactose oxidase, p-hydroxymercuribenzoic acid, 2,4,6-trinitrobenzensulfonic acid and sodium periodate, alpha-Mannosidase, N-ethylmaleimide and phospholipase C inactivated factor VIII procoagulant but not von Willebrand factor activity. Dithiothreitol had little effect on factor VIII procoagulant activity but reduced significantly that of von Willebrand factor. It is suggested that galactose and the thiol and epsilon-aminogroup groups of lysine may play an important role in both factor VIII procoagulant and von Willebrand factor activity. Mannose may be responsible for the factor VIII procoagulant activity but not for the von Willebrand factor activity. The Laurell rocket heights of factor VIII-related antigen rose with increasing concentration of galactose oxidase, 2,4,6-trinitrobenzenesulfonic acid or sodium periodate. Gel filtration experiments showed that factor VIII-related antigen may be dissociated into subunits by galactose oxidase but not by 2,4,6-trinitrobenzenesulfonic acid or sodium periodate.
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PMID:Studies of von Willebrand factor: effects of different kinds of carbohydrate oxidases, SH-inhibitors and some other chemical reagents. 30 2

The glycolipids of the protozoan Leishmania major strain LRC-L119 belong to a class of glycoinositol phospholipids (GIPL) that show partial structural homology to the phosphatidylinositol-containing glycolipid membrane anchors of several eukaryotic proteins and the lipid moiety of L. major lipophosphoglycan. The GIPLs were the only glycolipids detected and were purified by octyl-Sepharose and thin layer chromatographies. Analysis of the native and dephosphorylated glycolipids (GIPLs 1-6) by gas chromatography-mass spectrometry revealed that the glycan moieties have between 4 and 10 saccharide residues and all contain mannose, galactose, and non-N-acetylated glucosamine. Some of the GIPLs also contain glucose (GIPL-6) and hexose monophosphate residues (GIPL 4-6). The presence of an inositol phospholipid moiety in all the GIPLs is indicated by the identification of 1 myo-inositol monophosphate residue/molecule and their susceptibility to phosphatidylinositol-specific phospholipase C. However, heterogeneity in the lipid moieties is indicated by differences in the compositional analysis and the behavior of the GIPLs on the thin layer chromatography after mild alkali hydrolysis or phospholipase A2 treatment. These results demonstrate that GIPLs 1-4 contain 1-alkyl-2-acylglycerol composed of saturated unbranched alkyl chains with carbon chain lengths of 18-26 and acyl chains of myristate, palmitate and stearate, whereas GIPL-5 and -6 contain lyso-alkylglycerol composed of mainly C24:0 and C26:0 alkyl chains. Analysis of the products of nitrous acid deamination demonstrates that these glycerolipids are present as alkylacylphosphatidylinositol (GIPLs 1-4) and 1-O-alkylglycerophosphoinositol (GIPL-5 and -6), respectively. GIPL-2 and -3 are labeled on the surface of living promastigotes with galactose oxidase/NaB[3H]4. These GIPLs also react with three monoclonal antibodies that recognize the surface of promastigotes and amastigotes of L. major and other Leishmania spp.
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PMID:A family of glycoinositol phospholipids from Leishmania major. Isolation, characterization, and antigenicity. 291 Aug 65

The principal galactose oxidase/NaB[3H]4-labeled membrane protein of rat caudal epididymal spermatozoa was isolated by hydrophobic interaction chromatography. The protein is released from the membrane by the action of phosphatidylinositol specific phospholipase C, and thereby its properties are transformed from those of a protein anchored to the hydrophobic membrane to those of a hydrophilic solution protein. Because it is the only membrane-associated protein released by the enzyme which did not absorb to a propylaspartate resin, a simple, single step purification procedure was devised. Although the amino terminus of the protein is blocked to Edman degradation, the majority of the protein structure was determined from a series of tryptic peptides and from limited acid hydrolysis. Approximately 65% of the protein mass is carbohydrate which is primarily attached through O-glycosidic bonds to the 18 threonines. The molecular weight of the glycoprotein was estimated to be 16,600, considerably smaller than the M(r) = 26,000 to 37,000 previously determined by gel electrophoresis. The anomalous electrophoretic behavior is undoubtedly due to the large percentage of carbohydrate. The distribution of carbohydrate on the protein side chains suggests the protein may form a positively charged, specialized scaffolding for the presentation of the carbohydrate moieties. Because the appearance of the ability to label the protein with galactose oxidase is correlated with sperm maturation in the epididymis, the glycoprotein structures may be an important component in the fertilization process. The combination of linkage by glycosylphosphatidylinositol and low molecular weight mucin-like structure indicates this may be a member of a new class of membrane proteins.
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PMID:Characterization of a cell surface glycoprotein associated with maturation of rat spermatozoa. 812 26

Lipophosphoglycan-like glycoconjugates were isolated, purified and partially characterized from Tritrichomonas foetus and Trichomonas vaginalis. Cell surface radiolabeling of both trichomonads by the galactose oxidase/NaB[3H]4 technique indicated that the glycoconjugate was located on the cell surface of the parasites. The glycoconjugates were extracted from the delipidated residue fraction with the solvent, water/ethanol/diethylether/pyridine/NH4OH (15:15:5:1:0.017) and were purified to homogeneity by Sepharose CL-4B followed by octyl-Sepharose chromatography and methanol precipitation. The glycoconjugates migrated as broad bands upon SDS-PAGE. The T. foetus glycoconjugate contained large amounts of fucose along with some mannose, galactose, glucosamine and glucose and trace amounts of galactosamine and inositol. The T. vaginalis glycoconjugate appeared to contain large amounts of glucosamine and galactose along with some glucose, mannose and traces of galactosamine and inositol. The surface-labeled glycoconjugates from both parasites was found to be deaminated with nitrous acid and susceptible to phosphatidylinositol-specific phospholipase C, indicating the presence of a phospholipid anchor. Furthermore, these glycoconjugate were found to contain phosphate and were labile to hydrolysis by mild acid, strongly suggesting that the intact molecule is related to Leishmania lipophosphoglycans (LPG). The most striking and the unique features of these glycoconjugate molecules are the presence of large amounts of fucose in T. foetus and glucosamine in T. vaginalis along with the presence of galactosamine in both parasites. These results indicate that these glycoconjugates are new types of LPG-like molecules expressed on the trichomonad cell surface and are structurally distinct from Leishmania LPG.
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PMID:Lipophosphoglycan-like glycoconjugate of Tritrichomonas foetus and Trichomonas vaginalis. 843 19

Extracts of human liver were found to contain activities which copurified and coeluted with the two major subtypes of mediators (type A and type P) isolated from insulin-stimulated rat liver. The putative type A mediator from human liver inhibited cAMP-dependent protein kinase from bovine heart, decreased phosphoenolypyruvate carboxykinase mRNA levels in rat hepatoma cells, and stimulated lipogenesis in rat adipocytes. The putative type P mediator stimulated bovine heart pyruvate dehydrogenase phosphatase. Both fractions were able to stimulate proliferation of EGFR T17 fibroblasts and the type A was able to support growth in organotypic cultures of chicken embryo cochleovestibular ganglia. Both activities were resistant to Pronase treatment and the presence of carbohydrates, phosphate, and free-amino groups were confirmed in the two fractions. These properties are consistent with the structure/ function characteristics of the type A and P inositolphosphoglycans (IPG) previously characterized from rat liver. Further, the ability of the human-derived mediators to interact with rat adipocytes and bovine-derived metabolic enzymes suggests similarity in structure between the mediators purified from different species. Galactose oxidase-susceptible membrane-associated glycosylphosphatidylinositols (GPI) have been proposed to be the precursors of IPG. GPI was purified from human liver membranes followed by treatment with galactose oxidase and reduction with NaB3H4. Serial t.l.c. revealed three radiolabeled bands which comigrated with the putative GPI precursors found in rat liver. These galactose-oxidase-reactive lipidic compounds, however, were only partially susceptible to hydrolysis with phosphatidylinositol-specific phospholipase C from Bacillus thuringiensis and were resistant to glycosylphosphatidylinositol-specific phospholipase C from Trypanosoma brucei. These data indicate that IPG molecules with insulin-like biological activities are present in human liver.
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PMID:Isolation and partial characterisation of insulin-mimetic inositol phosphoglycans from human liver. 925 87